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1 | | /* Copyright (C) Sara Golemon <sarag@libssh2.org> |
2 | | * Copyright (C) Daniel Stenberg <daniel@haxx.se> |
3 | | * All rights reserved. |
4 | | * |
5 | | * Redistribution and use in source and binary forms, |
6 | | * with or without modification, are permitted provided |
7 | | * that the following conditions are met: |
8 | | * |
9 | | * Redistributions of source code must retain the above |
10 | | * copyright notice, this list of conditions and the |
11 | | * following disclaimer. |
12 | | * |
13 | | * Redistributions in binary form must reproduce the above |
14 | | * copyright notice, this list of conditions and the following |
15 | | * disclaimer in the documentation and/or other materials |
16 | | * provided with the distribution. |
17 | | * |
18 | | * Neither the name of the copyright holder nor the names |
19 | | * of any other contributors may be used to endorse or |
20 | | * promote products derived from this software without |
21 | | * specific prior written permission. |
22 | | * |
23 | | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
24 | | * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
25 | | * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
26 | | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
27 | | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
28 | | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
29 | | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
30 | | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
31 | | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
32 | | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
33 | | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
34 | | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE |
35 | | * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
36 | | * OF SUCH DAMAGE. |
37 | | * |
38 | | * SPDX-License-Identifier: BSD-3-Clause |
39 | | */ |
40 | | |
41 | | #include "libssh2_priv.h" |
42 | | |
43 | | #include "transport.h" |
44 | | #include "comp.h" |
45 | | #include "mac.h" |
46 | | |
47 | | #include <assert.h> |
48 | | |
49 | | /* define SHA1_DIGEST_LENGTH for the macro below */ |
50 | | #ifndef SHA1_DIGEST_LENGTH |
51 | 678 | #define SHA1_DIGEST_LENGTH SHA_DIGEST_LENGTH |
52 | | #endif |
53 | | |
54 | | /* TODO: Switch this to an inline and handle alloc() failures */ |
55 | | /* Helper macro called from |
56 | | kex_method_diffie_hellman_group1_sha1_key_exchange */ |
57 | | |
58 | | #if LIBSSH2_ECDSA |
59 | | #define LIBSSH2_KEX_METHOD_EC_SHA_VALUE_HASH(value, reqlen, version) \ |
60 | 0 | do { \ |
61 | 0 | if(type == LIBSSH2_EC_CURVE_NISTP256) { \ |
62 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(256, value, reqlen, version); \ |
63 | 0 | } \ |
64 | 0 | else if(type == LIBSSH2_EC_CURVE_NISTP384) { \ |
65 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(384, value, reqlen, version); \ |
66 | 0 | } \ |
67 | 0 | else if(type == LIBSSH2_EC_CURVE_NISTP521) { \ |
68 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(512, value, reqlen, version); \ |
69 | 0 | } \ |
70 | 0 | } while(0) |
71 | | #endif |
72 | | |
73 | | #define LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(digest_type, value, \ |
74 | 0 | reqlen, version) \ |
75 | 0 | do { \ |
76 | 0 | libssh2_sha##digest_type##_ctx hash; \ |
77 | 0 | size_t len = 0; \ |
78 | 0 | if(!(value)) { \ |
79 | 0 | value = LIBSSH2_ALLOC(session, \ |
80 | 0 | reqlen + SHA##digest_type##_DIGEST_LENGTH); \ |
81 | 0 | } \ |
82 | 0 | if(value) \ |
83 | 0 | while(len < (size_t)reqlen) { \ |
84 | 0 | if(!libssh2_sha##digest_type##_init(&hash) || \ |
85 | 0 | !libssh2_sha##digest_type##_update(hash, \ |
86 | 0 | exchange_state->k_value, \ |
87 | 0 | exchange_state->k_value_len) || \ |
88 | 0 | !libssh2_sha##digest_type##_update(hash, \ |
89 | 0 | exchange_state->h_sig_comp, \ |
90 | 0 | SHA##digest_type##_DIGEST_LENGTH)) { \ |
91 | 0 | LIBSSH2_FREE(session, value); \ |
92 | 0 | value = NULL; \ |
93 | 0 | break; \ |
94 | 0 | } \ |
95 | 0 | if(len > 0) { \ |
96 | 0 | if(!libssh2_sha##digest_type##_update(hash, value, len)) { \ |
97 | 0 | LIBSSH2_FREE(session, value); \ |
98 | 0 | value = NULL; \ |
99 | 0 | break; \ |
100 | 0 | } \ |
101 | 0 | } \ |
102 | 0 | else { \ |
103 | 0 | if(!libssh2_sha##digest_type##_update(hash, \ |
104 | 0 | (version), 1) || \ |
105 | 0 | !libssh2_sha##digest_type##_update(hash, \ |
106 | 0 | session->session_id, \ |
107 | 0 | session->session_id_len)) { \ |
108 | 0 | LIBSSH2_FREE(session, value); \ |
109 | 0 | value = NULL; \ |
110 | 0 | break; \ |
111 | 0 | } \ |
112 | 0 | } \ |
113 | 0 | if(!libssh2_sha##digest_type##_final(hash, (value) + len)) { \ |
114 | 0 | LIBSSH2_FREE(session, value); \ |
115 | 0 | value = NULL; \ |
116 | 0 | break; \ |
117 | 0 | } \ |
118 | 0 | len += SHA##digest_type##_DIGEST_LENGTH; \ |
119 | 0 | } \ |
120 | 0 | } while(0) |
121 | | |
122 | | /*! |
123 | | * @note The following are wrapper functions used by diffie_hellman_sha_algo(). |
124 | | * TODO: Switch backend SHA macros to functions to allow function pointers |
125 | | * @discussion Ideally these would be function pointers but the backend macros |
126 | | * don't allow it so we have to wrap them up in helper functions |
127 | | */ |
128 | | |
129 | | static int _libssh2_sha_algo_ctx_init(int sha_algo, void *ctx) |
130 | 18 | { |
131 | 18 | if(sha_algo == 512) { |
132 | 1 | return libssh2_sha512_init((libssh2_sha512_ctx*)ctx); |
133 | 1 | } |
134 | 17 | else if(sha_algo == 384) { |
135 | 0 | return libssh2_sha384_init((libssh2_sha384_ctx*)ctx); |
136 | 0 | } |
137 | 17 | else if(sha_algo == 256) { |
138 | 0 | return libssh2_sha256_init((libssh2_sha256_ctx*)ctx); |
139 | 0 | } |
140 | 17 | else if(sha_algo == 1) { |
141 | 17 | return libssh2_sha1_init((libssh2_sha1_ctx*)ctx); |
142 | 17 | } |
143 | 0 | else { |
144 | 0 | #ifdef LIBSSH2DEBUG |
145 | 0 | assert(0); |
146 | 0 | #endif |
147 | 0 | } |
148 | 0 | return 0; |
149 | 18 | } |
150 | | |
151 | | static int _libssh2_sha_algo_ctx_update(int sha_algo, void *ctx, |
152 | | const void *data, size_t len) |
153 | 252 | { |
154 | 252 | if(sha_algo == 512) { |
155 | 14 | libssh2_sha512_ctx *_ctx = (libssh2_sha512_ctx*)ctx; |
156 | 14 | return libssh2_sha512_update(*_ctx, data, len); |
157 | 14 | } |
158 | 238 | else if(sha_algo == 384) { |
159 | 0 | libssh2_sha384_ctx *_ctx = (libssh2_sha384_ctx*)ctx; |
160 | 0 | return libssh2_sha384_update(*_ctx, data, len); |
161 | 0 | } |
162 | 238 | else if(sha_algo == 256) { |
163 | 0 | libssh2_sha256_ctx *_ctx = (libssh2_sha256_ctx*)ctx; |
164 | 0 | return libssh2_sha256_update(*_ctx, data, len); |
165 | 0 | } |
166 | 238 | else if(sha_algo == 1) { |
167 | 238 | libssh2_sha1_ctx *_ctx = (libssh2_sha1_ctx*)ctx; |
168 | 238 | return libssh2_sha1_update(*_ctx, data, len); |
169 | 238 | } |
170 | 0 | else { |
171 | 0 | #ifdef LIBSSH2DEBUG |
172 | 0 | assert(0); |
173 | 0 | #endif |
174 | 0 | } |
175 | 0 | return 0; |
176 | 252 | } |
177 | | |
178 | | static int _libssh2_sha_algo_ctx_final(int sha_algo, void *ctx, |
179 | | void *hash) |
180 | 18 | { |
181 | 18 | if(sha_algo == 512) { |
182 | 1 | libssh2_sha512_ctx *_ctx = (libssh2_sha512_ctx*)ctx; |
183 | 1 | return libssh2_sha512_final(*_ctx, hash); |
184 | 1 | } |
185 | 17 | else if(sha_algo == 384) { |
186 | 0 | libssh2_sha384_ctx *_ctx = (libssh2_sha384_ctx*)ctx; |
187 | 0 | return libssh2_sha384_final(*_ctx, hash); |
188 | 0 | } |
189 | 17 | else if(sha_algo == 256) { |
190 | 0 | libssh2_sha256_ctx *_ctx = (libssh2_sha256_ctx*)ctx; |
191 | 0 | return libssh2_sha256_final(*_ctx, hash); |
192 | 0 | } |
193 | 17 | else if(sha_algo == 1) { |
194 | 17 | libssh2_sha1_ctx *_ctx = (libssh2_sha1_ctx*)ctx; |
195 | 17 | return libssh2_sha1_final(*_ctx, hash); |
196 | 17 | } |
197 | 0 | else { |
198 | 0 | #ifdef LIBSSH2DEBUG |
199 | 0 | assert(0); |
200 | 0 | #endif |
201 | 0 | } |
202 | 0 | return 0; |
203 | 18 | } |
204 | | |
205 | | static void _libssh2_sha_algo_value_hash(int sha_algo, |
206 | | LIBSSH2_SESSION *session, |
207 | | kmdhgGPshakex_state_t *exchange_state, |
208 | | unsigned char **data, size_t data_len, |
209 | | const unsigned char *version) |
210 | 0 | { |
211 | 0 | if(sha_algo == 512) { |
212 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(512, *data, data_len, version); |
213 | 0 | } |
214 | 0 | else if(sha_algo == 384) { |
215 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(384, *data, data_len, version); |
216 | 0 | } |
217 | 0 | else if(sha_algo == 256) { |
218 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(256, *data, data_len, version); |
219 | 0 | } |
220 | 0 | else if(sha_algo == 1) { |
221 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(1, *data, data_len, version); |
222 | 0 | } |
223 | 0 | else { |
224 | 0 | #ifdef LIBSSH2DEBUG |
225 | 0 | assert(0); |
226 | 0 | #endif |
227 | 0 | } |
228 | 0 | } |
229 | | |
230 | | |
231 | | static void |
232 | | diffie_hellman_state_cleanup(LIBSSH2_SESSION * session, |
233 | | kmdhgGPshakex_state_t *exchange_state) |
234 | 1.16k | { |
235 | 1.16k | libssh2_dh_dtor(&exchange_state->x); |
236 | 1.16k | _libssh2_bn_free(exchange_state->e); |
237 | 1.16k | exchange_state->e = NULL; |
238 | 1.16k | _libssh2_bn_free(exchange_state->f); |
239 | 1.16k | exchange_state->f = NULL; |
240 | 1.16k | _libssh2_bn_free(exchange_state->k); |
241 | 1.16k | exchange_state->k = NULL; |
242 | 1.16k | _libssh2_bn_ctx_free(exchange_state->ctx); |
243 | 1.16k | exchange_state->ctx = NULL; |
244 | | |
245 | 1.16k | if(exchange_state->e_packet) { |
246 | 909 | LIBSSH2_FREE(session, exchange_state->e_packet); |
247 | 909 | exchange_state->e_packet = NULL; |
248 | 909 | } |
249 | | |
250 | 1.16k | if(exchange_state->s_packet) { |
251 | 236 | LIBSSH2_FREE(session, exchange_state->s_packet); |
252 | 236 | exchange_state->s_packet = NULL; |
253 | 236 | } |
254 | | |
255 | 1.16k | if(exchange_state->k_value) { |
256 | 20 | LIBSSH2_FREE(session, exchange_state->k_value); |
257 | 20 | exchange_state->k_value = NULL; |
258 | 20 | } |
259 | | |
260 | 1.16k | exchange_state->state = libssh2_NB_state_idle; |
261 | 1.16k | } |
262 | | |
263 | | static void |
264 | | kex_diffie_hellman_cleanup(LIBSSH2_SESSION * session, |
265 | 2.80k | key_exchange_state_low_t * key_state) { |
266 | 2.80k | if(key_state->state != libssh2_NB_state_idle) { |
267 | 1.05k | _libssh2_bn_free(key_state->p); |
268 | 1.05k | key_state->p = NULL; |
269 | 1.05k | _libssh2_bn_free(key_state->g); |
270 | 1.05k | key_state->g = NULL; |
271 | | |
272 | 1.05k | if(key_state->data) { |
273 | 175 | LIBSSH2_FREE(session, key_state->data); |
274 | 175 | key_state->data = NULL; |
275 | 175 | } |
276 | 1.05k | key_state->state = libssh2_NB_state_idle; |
277 | 1.05k | } |
278 | | |
279 | 2.80k | if(key_state->exchange_state.state != libssh2_NB_state_idle) { |
280 | 0 | diffie_hellman_state_cleanup(session, &key_state->exchange_state); |
281 | 0 | } |
282 | 2.80k | } |
283 | | |
284 | | |
285 | | /*! |
286 | | * @function diffie_hellman_sha_algo |
287 | | * @abstract Diffie Hellman Key Exchange, Group Agnostic, |
288 | | * SHA Algorithm Agnostic |
289 | | * @result 0 on success, error code on failure |
290 | | */ |
291 | | static int diffie_hellman_sha_algo(LIBSSH2_SESSION *session, |
292 | | _libssh2_bn *g, |
293 | | _libssh2_bn *p, |
294 | | int group_order, |
295 | | int sha_algo_value, |
296 | | void *exchange_hash_ctx, |
297 | | unsigned char packet_type_init, |
298 | | unsigned char packet_type_reply, |
299 | | unsigned char *midhash, |
300 | | size_t midhash_len, |
301 | | kmdhgGPshakex_state_t *exchange_state) |
302 | 1.16k | { |
303 | 1.16k | int ret = 0; |
304 | 1.16k | int rc; |
305 | | |
306 | 1.16k | int digest_len = 0; |
307 | | |
308 | 1.16k | if(sha_algo_value == 512) |
309 | 308 | digest_len = SHA512_DIGEST_LENGTH; |
310 | 859 | else if(sha_algo_value == 384) |
311 | 0 | digest_len = SHA384_DIGEST_LENGTH; |
312 | 859 | else if(sha_algo_value == 256) |
313 | 181 | digest_len = SHA256_DIGEST_LENGTH; |
314 | 678 | else if(sha_algo_value == 1) |
315 | 678 | digest_len = SHA1_DIGEST_LENGTH; |
316 | 0 | else { |
317 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
318 | 0 | "sha algo value is unimplemented"); |
319 | 0 | goto clean_exit; |
320 | 0 | } |
321 | | |
322 | 1.16k | if(exchange_state->state == libssh2_NB_state_idle) { |
323 | | /* Setup initial values */ |
324 | 1.16k | exchange_state->e_packet = NULL; |
325 | 1.16k | exchange_state->s_packet = NULL; |
326 | 1.16k | exchange_state->k_value = NULL; |
327 | 1.16k | exchange_state->ctx = _libssh2_bn_ctx_new(); |
328 | 1.16k | libssh2_dh_init(&exchange_state->x); |
329 | 1.16k | exchange_state->e = _libssh2_bn_init(); /* g^x mod p */ |
330 | 1.16k | exchange_state->f = _libssh2_bn_init_from_bin(); /* g^(Random from |
331 | | server) mod p */ |
332 | 1.16k | exchange_state->k = _libssh2_bn_init(); /* The shared secret: f^x mod |
333 | | p */ |
334 | | |
335 | | /* Zero the whole thing out */ |
336 | 1.16k | memset(&exchange_state->req_state, 0, sizeof(packet_require_state_t)); |
337 | | |
338 | | /* Generate x and e */ |
339 | 1.16k | if(_libssh2_bn_bits(p) > LIBSSH2_DH_MAX_MODULUS_BITS) { |
340 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_INVAL, |
341 | 0 | "dh modulus value is too large"); |
342 | 0 | goto clean_exit; |
343 | 0 | } |
344 | | |
345 | 1.16k | rc = libssh2_dh_key_pair(&exchange_state->x, exchange_state->e, g, p, |
346 | 1.16k | group_order, exchange_state->ctx); |
347 | 1.16k | if(rc) { |
348 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_KEX_FAILURE, |
349 | 0 | "dh key pair generation failed"); |
350 | 0 | goto clean_exit; |
351 | 0 | } |
352 | | |
353 | | /* Send KEX init */ |
354 | | /* packet_type(1) + String Length(4) + leading 0(1) */ |
355 | 1.16k | exchange_state->e_packet_len = |
356 | 1.16k | _libssh2_bn_bytes(exchange_state->e) + 6; |
357 | 1.16k | if(_libssh2_bn_bits(exchange_state->e) % 8) { |
358 | | /* Leading 00 not needed */ |
359 | 652 | exchange_state->e_packet_len--; |
360 | 652 | } |
361 | | |
362 | 1.16k | exchange_state->e_packet = |
363 | 1.16k | LIBSSH2_ALLOC(session, exchange_state->e_packet_len); |
364 | 1.16k | if(!exchange_state->e_packet) { |
365 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
366 | 0 | "Out of memory error"); |
367 | 0 | goto clean_exit; |
368 | 0 | } |
369 | 1.16k | exchange_state->e_packet[0] = packet_type_init; |
370 | 1.16k | _libssh2_htonu32(exchange_state->e_packet + 1, |
371 | 1.16k | (uint32_t)(exchange_state->e_packet_len - 5)); |
372 | 1.16k | if(_libssh2_bn_bits(exchange_state->e) % 8) { |
373 | 652 | if(_libssh2_bn_to_bin(exchange_state->e, |
374 | 652 | exchange_state->e_packet + 5)) { |
375 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY, |
376 | 0 | "Can't write exchange_state->e"); |
377 | 0 | goto clean_exit; |
378 | 0 | } |
379 | 652 | } |
380 | 515 | else { |
381 | 515 | exchange_state->e_packet[5] = 0; |
382 | 515 | if(_libssh2_bn_to_bin(exchange_state->e, |
383 | 515 | exchange_state->e_packet + 6)) { |
384 | 5 | ret = _libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY, |
385 | 5 | "Can't write exchange_state->e"); |
386 | 5 | goto clean_exit; |
387 | 5 | } |
388 | 515 | } |
389 | | |
390 | 1.16k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, "Sending KEX packet %u", |
391 | 1.16k | (unsigned int) packet_type_init)); |
392 | 1.16k | exchange_state->state = libssh2_NB_state_created; |
393 | 1.16k | } |
394 | | |
395 | 1.16k | if(exchange_state->state == libssh2_NB_state_created) { |
396 | 1.16k | rc = _libssh2_transport_send(session, exchange_state->e_packet, |
397 | 1.16k | exchange_state->e_packet_len, |
398 | 1.16k | NULL, 0); |
399 | 1.16k | if(rc == LIBSSH2_ERROR_EAGAIN) { |
400 | 0 | return rc; |
401 | 0 | } |
402 | 1.16k | else if(rc) { |
403 | 0 | ret = _libssh2_error(session, rc, |
404 | 0 | "Unable to send KEX init message"); |
405 | 0 | goto clean_exit; |
406 | 0 | } |
407 | 1.16k | exchange_state->state = libssh2_NB_state_sent; |
408 | 1.16k | } |
409 | | |
410 | 1.16k | if(exchange_state->state == libssh2_NB_state_sent) { |
411 | 1.16k | if(session->burn_optimistic_kexinit) { |
412 | | /* The first KEX packet to come along will be the guess initially |
413 | | * sent by the server. That guess turned out to be wrong so we |
414 | | * need to silently ignore it */ |
415 | 527 | int burn_type; |
416 | | |
417 | 527 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
418 | 527 | "Waiting for badly guessed KEX packet " |
419 | 527 | "(to be ignored)")); |
420 | 527 | burn_type = |
421 | 527 | _libssh2_packet_burn(session, &exchange_state->burn_state); |
422 | 527 | if(burn_type == LIBSSH2_ERROR_EAGAIN) { |
423 | 0 | return burn_type; |
424 | 0 | } |
425 | 527 | else if(burn_type <= 0) { |
426 | | /* Failed to receive a packet */ |
427 | 254 | ret = burn_type; |
428 | 254 | goto clean_exit; |
429 | 254 | } |
430 | 273 | session->burn_optimistic_kexinit = 0; |
431 | | |
432 | 273 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
433 | 273 | "Burnt packet of type: %02x", |
434 | 273 | (unsigned int) burn_type)); |
435 | 273 | } |
436 | | |
437 | 908 | exchange_state->state = libssh2_NB_state_sent1; |
438 | 908 | } |
439 | | |
440 | 908 | if(exchange_state->state == libssh2_NB_state_sent1) { |
441 | | /* Wait for KEX reply */ |
442 | 908 | struct string_buf buf; |
443 | 908 | size_t host_key_len; |
444 | 908 | int err; |
445 | 908 | int hok; |
446 | | |
447 | 908 | rc = _libssh2_packet_require(session, packet_type_reply, |
448 | 908 | &exchange_state->s_packet, |
449 | 908 | &exchange_state->s_packet_len, 0, NULL, |
450 | 908 | 0, &exchange_state->req_state); |
451 | 908 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
452 | 0 | return rc; |
453 | 0 | } |
454 | 908 | if(rc) { |
455 | 672 | ret = _libssh2_error(session, LIBSSH2_ERROR_TIMEOUT, |
456 | 672 | "Timed out waiting for KEX reply"); |
457 | 672 | goto clean_exit; |
458 | 672 | } |
459 | | |
460 | | /* Parse KEXDH_REPLY */ |
461 | 236 | if(exchange_state->s_packet_len < 5) { |
462 | 2 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
463 | 2 | "Unexpected packet length DH-SHA"); |
464 | 2 | goto clean_exit; |
465 | 2 | } |
466 | | |
467 | 234 | buf.data = exchange_state->s_packet; |
468 | 234 | buf.len = exchange_state->s_packet_len; |
469 | 234 | buf.dataptr = buf.data; |
470 | 234 | buf.dataptr++; /* advance past type */ |
471 | | |
472 | 234 | if(session->server_hostkey) { |
473 | 0 | LIBSSH2_FREE(session, session->server_hostkey); |
474 | 0 | session->server_hostkey = NULL; |
475 | 0 | session->server_hostkey_len = 0; |
476 | 0 | } |
477 | | |
478 | 234 | if(_libssh2_copy_string(session, &buf, &(session->server_hostkey), |
479 | 234 | &host_key_len)) { |
480 | 3 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
481 | 3 | "Could not copy host key"); |
482 | 3 | goto clean_exit; |
483 | 3 | } |
484 | | |
485 | 231 | session->server_hostkey_len = (uint32_t)host_key_len; |
486 | | |
487 | | #if LIBSSH2_MD5 |
488 | | { |
489 | | libssh2_md5_ctx fingerprint_ctx; |
490 | | |
491 | | if(libssh2_md5_init(&fingerprint_ctx) && |
492 | | libssh2_md5_update(fingerprint_ctx, session->server_hostkey, |
493 | | session->server_hostkey_len) && |
494 | | libssh2_md5_final(fingerprint_ctx, |
495 | | session->server_hostkey_md5)) { |
496 | | session->server_hostkey_md5_valid = TRUE; |
497 | | } |
498 | | else { |
499 | | session->server_hostkey_md5_valid = FALSE; |
500 | | } |
501 | | } |
502 | | #ifdef LIBSSH2DEBUG |
503 | | { |
504 | | char fingerprint[50], *fprint = fingerprint; |
505 | | int i; |
506 | | for(i = 0; i < 16; i++, fprint += 3) { |
507 | | snprintf(fprint, 4, "%02x:", session->server_hostkey_md5[i]); |
508 | | } |
509 | | *(--fprint) = '\0'; |
510 | | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
511 | | "Server's MD5 Fingerprint: %s", fingerprint)); |
512 | | } |
513 | | #endif /* LIBSSH2DEBUG */ |
514 | | #endif /* ! LIBSSH2_MD5 */ |
515 | | |
516 | 231 | { |
517 | 231 | libssh2_sha1_ctx fingerprint_ctx; |
518 | | |
519 | 231 | if(libssh2_sha1_init(&fingerprint_ctx) && |
520 | 231 | libssh2_sha1_update(fingerprint_ctx, session->server_hostkey, |
521 | 231 | session->server_hostkey_len) && |
522 | 231 | libssh2_sha1_final(fingerprint_ctx, |
523 | 231 | session->server_hostkey_sha1)) { |
524 | 231 | session->server_hostkey_sha1_valid = TRUE; |
525 | 231 | } |
526 | 0 | else { |
527 | 0 | session->server_hostkey_sha1_valid = FALSE; |
528 | 0 | } |
529 | 231 | } |
530 | 231 | #ifdef LIBSSH2DEBUG |
531 | 231 | { |
532 | 231 | char fingerprint[64], *fprint = fingerprint; |
533 | 231 | int i; |
534 | 4.85k | for(i = 0; i < 20; i++, fprint += 3) { |
535 | 4.62k | snprintf(fprint, 4, "%02x:", session->server_hostkey_sha1[i]); |
536 | 4.62k | } |
537 | 231 | *(--fprint) = '\0'; |
538 | 231 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
539 | 231 | "Server's SHA1 Fingerprint: %s", fingerprint)); |
540 | 231 | } |
541 | 231 | #endif /* LIBSSH2DEBUG */ |
542 | | |
543 | 231 | { |
544 | 231 | libssh2_sha256_ctx fingerprint_ctx; |
545 | | |
546 | 231 | if(libssh2_sha256_init(&fingerprint_ctx) && |
547 | 231 | libssh2_sha256_update(fingerprint_ctx, session->server_hostkey, |
548 | 231 | session->server_hostkey_len) && |
549 | 231 | libssh2_sha256_final(fingerprint_ctx, |
550 | 231 | session->server_hostkey_sha256)) { |
551 | 231 | session->server_hostkey_sha256_valid = TRUE; |
552 | 231 | } |
553 | 0 | else { |
554 | 0 | session->server_hostkey_sha256_valid = FALSE; |
555 | 0 | } |
556 | 231 | } |
557 | 231 | #ifdef LIBSSH2DEBUG |
558 | 231 | { |
559 | 231 | char *base64Fingerprint = NULL; |
560 | 231 | _libssh2_base64_encode(session, |
561 | 231 | (const char *) |
562 | 231 | session->server_hostkey_sha256, |
563 | 231 | SHA256_DIGEST_LENGTH, &base64Fingerprint); |
564 | 231 | if(base64Fingerprint) { |
565 | 231 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
566 | 231 | "Server's SHA256 Fingerprint: %s", |
567 | 231 | base64Fingerprint)); |
568 | 231 | LIBSSH2_FREE(session, base64Fingerprint); |
569 | 231 | } |
570 | 231 | } |
571 | 231 | #endif /* LIBSSH2DEBUG */ |
572 | | |
573 | | |
574 | 231 | if(!session->hostkey) { |
575 | 1 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
576 | 1 | "hostkey is NULL"); |
577 | 1 | goto clean_exit; |
578 | 1 | } |
579 | 230 | if(session->hostkey->init(session, session->server_hostkey, |
580 | 230 | session->server_hostkey_len, |
581 | 230 | &session->server_hostkey_abstract)) { |
582 | 208 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, |
583 | 208 | "Unable to initialize hostkey importer " |
584 | 208 | "DH-SHA"); |
585 | 208 | goto clean_exit; |
586 | 208 | } |
587 | | |
588 | 22 | if(_libssh2_get_string(&buf, &(exchange_state->f_value), |
589 | 22 | &(exchange_state->f_value_len))) { |
590 | 1 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, |
591 | 1 | "Unable to get DH-SHA f value"); |
592 | 1 | goto clean_exit; |
593 | 1 | } |
594 | | |
595 | 21 | if(_libssh2_bn_from_bin(exchange_state->f, |
596 | 21 | exchange_state->f_value_len, |
597 | 21 | exchange_state->f_value)) { |
598 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, |
599 | 0 | "Invalid DH-SHA f value"); |
600 | 0 | goto clean_exit; |
601 | 0 | } |
602 | | |
603 | 21 | if(_libssh2_get_string(&buf, &(exchange_state->h_sig), |
604 | 21 | &(exchange_state->h_sig_len))) { |
605 | 1 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, |
606 | 1 | "Unable to get DH-SHA h sig"); |
607 | 1 | goto clean_exit; |
608 | 1 | } |
609 | | |
610 | | /* Compute the shared secret */ |
611 | 20 | libssh2_dh_secret(&exchange_state->x, exchange_state->k, |
612 | 20 | exchange_state->f, p, exchange_state->ctx); |
613 | 20 | exchange_state->k_value_len = _libssh2_bn_bytes(exchange_state->k) + 5; |
614 | 20 | if(_libssh2_bn_bits(exchange_state->k) % 8) { |
615 | | /* don't need leading 00 */ |
616 | 6 | exchange_state->k_value_len--; |
617 | 6 | } |
618 | 20 | exchange_state->k_value = |
619 | 20 | LIBSSH2_ALLOC(session, exchange_state->k_value_len); |
620 | 20 | if(!exchange_state->k_value) { |
621 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
622 | 0 | "Unable to allocate buffer for DH-SHA K"); |
623 | 0 | goto clean_exit; |
624 | 0 | } |
625 | 20 | _libssh2_htonu32(exchange_state->k_value, |
626 | 20 | (uint32_t)(exchange_state->k_value_len - 4)); |
627 | 20 | if(_libssh2_bn_bits(exchange_state->k) % 8) { |
628 | 6 | if(_libssh2_bn_to_bin(exchange_state->k, |
629 | 6 | exchange_state->k_value + 4)) { |
630 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY, |
631 | 0 | "Can't write exchange_state->k"); |
632 | 0 | goto clean_exit; |
633 | 0 | } |
634 | 6 | } |
635 | 14 | else { |
636 | 14 | exchange_state->k_value[4] = 0; |
637 | 14 | if(_libssh2_bn_to_bin(exchange_state->k, |
638 | 14 | exchange_state->k_value + 5)) { |
639 | 2 | ret = _libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY, |
640 | 2 | "Can't write exchange_state->k"); |
641 | 2 | goto clean_exit; |
642 | 2 | } |
643 | 14 | } |
644 | | |
645 | 18 | exchange_state->exchange_hash = (void *)&exchange_hash_ctx; |
646 | 18 | if(!_libssh2_sha_algo_ctx_init(sha_algo_value, exchange_hash_ctx)) { |
647 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_HASH_INIT, |
648 | 0 | "Unable to initialize hash context"); |
649 | 0 | goto clean_exit; |
650 | 0 | } |
651 | 18 | hok = 1; |
652 | 18 | if(session->local.banner) { |
653 | 0 | _libssh2_htonu32(exchange_state->h_sig_comp, |
654 | 0 | (uint32_t)(strlen((char *) session->local.banner) - 2)); |
655 | 0 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, |
656 | 0 | exchange_hash_ctx, |
657 | 0 | exchange_state->h_sig_comp, 4); |
658 | 0 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, |
659 | 0 | exchange_hash_ctx, |
660 | 0 | session->local.banner, |
661 | 0 | strlen((char *) session->local.banner) - 2); |
662 | 0 | } |
663 | 18 | else { |
664 | 18 | _libssh2_htonu32(exchange_state->h_sig_comp, |
665 | 18 | sizeof(LIBSSH2_SSH_DEFAULT_BANNER) - 1); |
666 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, |
667 | 18 | exchange_hash_ctx, |
668 | 18 | exchange_state->h_sig_comp, 4); |
669 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, |
670 | 18 | exchange_hash_ctx, |
671 | 18 | (const void *)LIBSSH2_SSH_DEFAULT_BANNER, |
672 | 18 | sizeof(LIBSSH2_SSH_DEFAULT_BANNER) - 1); |
673 | 18 | } |
674 | | |
675 | 18 | _libssh2_htonu32(exchange_state->h_sig_comp, |
676 | 18 | (uint32_t)strlen((char *) session->remote.banner)); |
677 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
678 | 18 | exchange_state->h_sig_comp, 4); |
679 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
680 | 18 | session->remote.banner, |
681 | 18 | strlen((char *)session->remote.banner)); |
682 | | |
683 | 18 | _libssh2_htonu32(exchange_state->h_sig_comp, |
684 | 18 | (uint32_t)session->local.kexinit_len); |
685 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
686 | 18 | exchange_state->h_sig_comp, 4); |
687 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
688 | 18 | session->local.kexinit, |
689 | 18 | session->local.kexinit_len); |
690 | | |
691 | 18 | _libssh2_htonu32(exchange_state->h_sig_comp, |
692 | 18 | (uint32_t)session->remote.kexinit_len); |
693 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
694 | 18 | exchange_state->h_sig_comp, 4); |
695 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
696 | 18 | session->remote.kexinit, |
697 | 18 | session->remote.kexinit_len); |
698 | | |
699 | 18 | _libssh2_htonu32(exchange_state->h_sig_comp, |
700 | 18 | session->server_hostkey_len); |
701 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
702 | 18 | exchange_state->h_sig_comp, 4); |
703 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
704 | 18 | session->server_hostkey, |
705 | 18 | session->server_hostkey_len); |
706 | | |
707 | 18 | if(packet_type_init == SSH_MSG_KEX_DH_GEX_INIT) { |
708 | | /* diffie-hellman-group-exchange hashes additional fields */ |
709 | 0 | _libssh2_htonu32(exchange_state->h_sig_comp, |
710 | 0 | LIBSSH2_DH_GEX_MINGROUP); |
711 | 0 | _libssh2_htonu32(exchange_state->h_sig_comp + 4, |
712 | 0 | LIBSSH2_DH_GEX_OPTGROUP); |
713 | 0 | _libssh2_htonu32(exchange_state->h_sig_comp + 8, |
714 | 0 | LIBSSH2_DH_GEX_MAXGROUP); |
715 | 0 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, |
716 | 0 | exchange_hash_ctx, |
717 | 0 | exchange_state->h_sig_comp, |
718 | 0 | 12); |
719 | 0 | } |
720 | | |
721 | 18 | if(midhash) { |
722 | 0 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, |
723 | 0 | exchange_hash_ctx, |
724 | 0 | midhash, midhash_len); |
725 | 0 | } |
726 | | |
727 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
728 | 18 | exchange_state->e_packet + 1, |
729 | 18 | exchange_state->e_packet_len - 1); |
730 | | |
731 | 18 | _libssh2_htonu32(exchange_state->h_sig_comp, |
732 | 18 | (uint32_t)exchange_state->f_value_len); |
733 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
734 | 18 | exchange_state->h_sig_comp, 4); |
735 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
736 | 18 | exchange_state->f_value, |
737 | 18 | exchange_state->f_value_len); |
738 | | |
739 | 18 | hok &= _libssh2_sha_algo_ctx_update(sha_algo_value, exchange_hash_ctx, |
740 | 18 | exchange_state->k_value, |
741 | 18 | exchange_state->k_value_len); |
742 | | |
743 | 18 | if(!hok || |
744 | 18 | !_libssh2_sha_algo_ctx_final(sha_algo_value, exchange_hash_ctx, |
745 | 18 | exchange_state->h_sig_comp)) { |
746 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_HASH_CALC, |
747 | 0 | "kex: failed to calculate hash"); |
748 | 0 | goto clean_exit; |
749 | 0 | } |
750 | | |
751 | 18 | err = session->hostkey->sig_verify(session, |
752 | 18 | exchange_state->h_sig, |
753 | 18 | exchange_state->h_sig_len, |
754 | 18 | exchange_state->h_sig_comp, |
755 | 18 | digest_len, |
756 | 18 | &session->server_hostkey_abstract); |
757 | | |
758 | 18 | if(err) { |
759 | 18 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
760 | 18 | "Failed hostkey sig_verify(): %s: %d", |
761 | 18 | session->hostkey->name, err)); |
762 | 18 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_SIGN, |
763 | 18 | "Unable to verify hostkey signature " |
764 | 18 | "DH-SHA"); |
765 | 18 | goto clean_exit; |
766 | 18 | } |
767 | | |
768 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
769 | 0 | "Sending NEWKEYS message")); |
770 | 0 | exchange_state->c = SSH_MSG_NEWKEYS; |
771 | |
|
772 | 0 | exchange_state->state = libssh2_NB_state_sent2; |
773 | 0 | } |
774 | | |
775 | 0 | if(exchange_state->state == libssh2_NB_state_sent2) { |
776 | 0 | rc = _libssh2_transport_send(session, &exchange_state->c, 1, NULL, 0); |
777 | 0 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
778 | 0 | return rc; |
779 | 0 | } |
780 | 0 | else if(rc) { |
781 | 0 | ret = _libssh2_error(session, rc, |
782 | 0 | "Unable to send NEWKEYS message DH-SHA"); |
783 | 0 | goto clean_exit; |
784 | 0 | } |
785 | | |
786 | 0 | exchange_state->state = libssh2_NB_state_sent3; |
787 | 0 | } |
788 | | |
789 | 0 | if(exchange_state->state == libssh2_NB_state_sent3) { |
790 | 0 | rc = _libssh2_packet_require(session, SSH_MSG_NEWKEYS, |
791 | 0 | &exchange_state->tmp, |
792 | 0 | &exchange_state->tmp_len, 0, NULL, 0, |
793 | 0 | &exchange_state->req_state); |
794 | 0 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
795 | 0 | return rc; |
796 | 0 | } |
797 | 0 | else if(rc) { |
798 | 0 | ret = _libssh2_error(session, rc, |
799 | 0 | "Timed out waiting for NEWKEYS DH-SHA"); |
800 | 0 | goto clean_exit; |
801 | 0 | } |
802 | | |
803 | | /* The first key exchange has been performed, |
804 | | switch to active crypt/comp/mac mode */ |
805 | 0 | session->state |= LIBSSH2_STATE_NEWKEYS; |
806 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
807 | 0 | "Received NEWKEYS message DH-SHA")); |
808 | | |
809 | | /* This will actually end up being just packet_type(1) |
810 | | for this packet type anyway */ |
811 | 0 | LIBSSH2_FREE(session, exchange_state->tmp); |
812 | |
|
813 | 0 | if(!session->session_id) { |
814 | 0 | session->session_id = LIBSSH2_ALLOC(session, digest_len); |
815 | 0 | if(!session->session_id) { |
816 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
817 | 0 | "Unable to allocate buffer for " |
818 | 0 | "SHA digest"); |
819 | 0 | goto clean_exit; |
820 | 0 | } |
821 | 0 | memcpy(session->session_id, exchange_state->h_sig_comp, |
822 | 0 | digest_len); |
823 | 0 | session->session_id_len = digest_len; |
824 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
825 | 0 | "session_id calculated")); |
826 | 0 | } |
827 | | |
828 | | /* Cleanup any existing cipher */ |
829 | 0 | if(session->local.crypt->dtor) { |
830 | 0 | session->local.crypt->dtor(session, |
831 | 0 | &session->local.crypt_abstract); |
832 | 0 | } |
833 | | |
834 | | /* Calculate IV/Secret/Key for each direction */ |
835 | 0 | if(session->local.crypt->init) { |
836 | 0 | unsigned char *iv = NULL, *secret = NULL; |
837 | 0 | int free_iv = 0, free_secret = 0; |
838 | |
|
839 | 0 | _libssh2_sha_algo_value_hash(sha_algo_value, session, |
840 | 0 | exchange_state, &iv, |
841 | 0 | session->local.crypt->iv_len, |
842 | 0 | (const unsigned char *)"A"); |
843 | |
|
844 | 0 | if(!iv) { |
845 | 0 | ret = -1; |
846 | 0 | goto clean_exit; |
847 | 0 | } |
848 | 0 | _libssh2_sha_algo_value_hash(sha_algo_value, session, |
849 | 0 | exchange_state, &secret, |
850 | 0 | session->local.crypt->secret_len, |
851 | 0 | (const unsigned char *)"C"); |
852 | |
|
853 | 0 | if(!secret) { |
854 | 0 | LIBSSH2_FREE(session, iv); |
855 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
856 | 0 | goto clean_exit; |
857 | 0 | } |
858 | 0 | if(session->local.crypt-> |
859 | 0 | init(session, session->local.crypt, iv, &free_iv, secret, |
860 | 0 | &free_secret, 1, &session->local.crypt_abstract)) { |
861 | 0 | LIBSSH2_FREE(session, iv); |
862 | 0 | LIBSSH2_FREE(session, secret); |
863 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
864 | 0 | goto clean_exit; |
865 | 0 | } |
866 | | |
867 | 0 | if(free_iv) { |
868 | 0 | _libssh2_explicit_zero(iv, session->local.crypt->iv_len); |
869 | 0 | LIBSSH2_FREE(session, iv); |
870 | 0 | } |
871 | |
|
872 | 0 | if(free_secret) { |
873 | 0 | _libssh2_explicit_zero(secret, |
874 | 0 | session->local.crypt->secret_len); |
875 | 0 | LIBSSH2_FREE(session, secret); |
876 | 0 | } |
877 | 0 | } |
878 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
879 | 0 | "Client to Server IV and Key calculated")); |
880 | |
|
881 | 0 | if(session->remote.crypt->dtor) { |
882 | | /* Cleanup any existing cipher */ |
883 | 0 | session->remote.crypt->dtor(session, |
884 | 0 | &session->remote.crypt_abstract); |
885 | 0 | } |
886 | |
|
887 | 0 | if(session->remote.crypt->init) { |
888 | 0 | unsigned char *iv = NULL, *secret = NULL; |
889 | 0 | int free_iv = 0, free_secret = 0; |
890 | |
|
891 | 0 | _libssh2_sha_algo_value_hash(sha_algo_value, session, |
892 | 0 | exchange_state, &iv, |
893 | 0 | session->remote.crypt->iv_len, |
894 | 0 | (const unsigned char *)"B"); |
895 | 0 | if(!iv) { |
896 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
897 | 0 | goto clean_exit; |
898 | 0 | } |
899 | 0 | _libssh2_sha_algo_value_hash(sha_algo_value, session, |
900 | 0 | exchange_state, &secret, |
901 | 0 | session->remote.crypt->secret_len, |
902 | 0 | (const unsigned char *)"D"); |
903 | 0 | if(!secret) { |
904 | 0 | LIBSSH2_FREE(session, iv); |
905 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
906 | 0 | goto clean_exit; |
907 | 0 | } |
908 | 0 | if(session->remote.crypt-> |
909 | 0 | init(session, session->remote.crypt, iv, &free_iv, secret, |
910 | 0 | &free_secret, 0, &session->remote.crypt_abstract)) { |
911 | 0 | LIBSSH2_FREE(session, iv); |
912 | 0 | LIBSSH2_FREE(session, secret); |
913 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
914 | 0 | goto clean_exit; |
915 | 0 | } |
916 | | |
917 | 0 | if(free_iv) { |
918 | 0 | _libssh2_explicit_zero(iv, session->remote.crypt->iv_len); |
919 | 0 | LIBSSH2_FREE(session, iv); |
920 | 0 | } |
921 | |
|
922 | 0 | if(free_secret) { |
923 | 0 | _libssh2_explicit_zero(secret, |
924 | 0 | session->remote.crypt->secret_len); |
925 | 0 | LIBSSH2_FREE(session, secret); |
926 | 0 | } |
927 | 0 | } |
928 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
929 | 0 | "Server to Client IV and Key calculated")); |
930 | |
|
931 | 0 | if(session->local.mac->dtor) { |
932 | 0 | session->local.mac->dtor(session, &session->local.mac_abstract); |
933 | 0 | } |
934 | |
|
935 | 0 | if(session->local.mac->init) { |
936 | 0 | unsigned char *key = NULL; |
937 | 0 | int free_key = 0; |
938 | |
|
939 | 0 | _libssh2_sha_algo_value_hash(sha_algo_value, session, |
940 | 0 | exchange_state, &key, |
941 | 0 | session->local.mac->key_len, |
942 | 0 | (const unsigned char *)"E"); |
943 | 0 | if(!key) { |
944 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
945 | 0 | goto clean_exit; |
946 | 0 | } |
947 | 0 | session->local.mac->init(session, key, &free_key, |
948 | 0 | &session->local.mac_abstract); |
949 | |
|
950 | 0 | if(free_key) { |
951 | 0 | _libssh2_explicit_zero(key, session->local.mac->key_len); |
952 | 0 | LIBSSH2_FREE(session, key); |
953 | 0 | } |
954 | 0 | } |
955 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
956 | 0 | "Client to Server HMAC Key calculated")); |
957 | |
|
958 | 0 | if(session->remote.mac->dtor) { |
959 | 0 | session->remote.mac->dtor(session, &session->remote.mac_abstract); |
960 | 0 | } |
961 | |
|
962 | 0 | if(session->remote.mac->init) { |
963 | 0 | unsigned char *key = NULL; |
964 | 0 | int free_key = 0; |
965 | |
|
966 | 0 | _libssh2_sha_algo_value_hash(sha_algo_value, session, |
967 | 0 | exchange_state, &key, |
968 | 0 | session->remote.mac->key_len, |
969 | 0 | (const unsigned char *)"F"); |
970 | 0 | if(!key) { |
971 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
972 | 0 | goto clean_exit; |
973 | 0 | } |
974 | 0 | session->remote.mac->init(session, key, &free_key, |
975 | 0 | &session->remote.mac_abstract); |
976 | |
|
977 | 0 | if(free_key) { |
978 | 0 | _libssh2_explicit_zero(key, session->remote.mac->key_len); |
979 | 0 | LIBSSH2_FREE(session, key); |
980 | 0 | } |
981 | 0 | } |
982 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
983 | 0 | "Server to Client HMAC Key calculated")); |
984 | | |
985 | | /* Initialize compression for each direction */ |
986 | | |
987 | | /* Cleanup any existing compression */ |
988 | 0 | if(session->local.comp && session->local.comp->dtor) { |
989 | 0 | session->local.comp->dtor(session, 1, |
990 | 0 | &session->local.comp_abstract); |
991 | 0 | } |
992 | |
|
993 | 0 | if(session->local.comp && session->local.comp->init) { |
994 | 0 | if(session->local.comp->init(session, 1, |
995 | 0 | &session->local.comp_abstract)) { |
996 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
997 | 0 | goto clean_exit; |
998 | 0 | } |
999 | 0 | } |
1000 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
1001 | 0 | "Client to Server compression initialized")); |
1002 | |
|
1003 | 0 | if(session->remote.comp && session->remote.comp->dtor) { |
1004 | 0 | session->remote.comp->dtor(session, 0, |
1005 | 0 | &session->remote.comp_abstract); |
1006 | 0 | } |
1007 | |
|
1008 | 0 | if(session->remote.comp && session->remote.comp->init) { |
1009 | 0 | if(session->remote.comp->init(session, 0, |
1010 | 0 | &session->remote.comp_abstract)) { |
1011 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
1012 | 0 | goto clean_exit; |
1013 | 0 | } |
1014 | 0 | } |
1015 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
1016 | 0 | "Server to Client compression initialized")); |
1017 | |
|
1018 | 0 | } |
1019 | | |
1020 | 1.16k | clean_exit: |
1021 | 1.16k | diffie_hellman_state_cleanup(session, exchange_state); |
1022 | | |
1023 | 1.16k | return ret; |
1024 | 0 | } |
1025 | | |
1026 | | |
1027 | | |
1028 | | /* kex_method_diffie_hellman_group1_sha1_key_exchange |
1029 | | * Diffie-Hellman Group1 (Actually Group2) Key Exchange using SHA1 |
1030 | | */ |
1031 | | static int |
1032 | | kex_method_diffie_hellman_group1_sha1_key_exchange(LIBSSH2_SESSION *session, |
1033 | | key_exchange_state_low_t |
1034 | | * key_state) |
1035 | 393 | { |
1036 | 393 | static const unsigned char p_value[128] = { |
1037 | 393 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
1038 | 393 | 0xC9, 0x0F, 0xDA, 0xA2, 0x21, 0x68, 0xC2, 0x34, |
1039 | 393 | 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1, |
1040 | 393 | 0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, |
1041 | 393 | 0x02, 0x0B, 0xBE, 0xA6, 0x3B, 0x13, 0x9B, 0x22, |
1042 | 393 | 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD, |
1043 | 393 | 0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, |
1044 | 393 | 0x30, 0x2B, 0x0A, 0x6D, 0xF2, 0x5F, 0x14, 0x37, |
1045 | 393 | 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45, |
1046 | 393 | 0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, |
1047 | 393 | 0xF4, 0x4C, 0x42, 0xE9, 0xA6, 0x37, 0xED, 0x6B, |
1048 | 393 | 0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED, |
1049 | 393 | 0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5, |
1050 | 393 | 0xAE, 0x9F, 0x24, 0x11, 0x7C, 0x4B, 0x1F, 0xE6, |
1051 | 393 | 0x49, 0x28, 0x66, 0x51, 0xEC, 0xE6, 0x53, 0x81, |
1052 | 393 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF |
1053 | 393 | }; |
1054 | | |
1055 | 393 | int ret; |
1056 | 393 | libssh2_sha1_ctx exchange_hash_ctx; |
1057 | | |
1058 | 393 | if(key_state->state == libssh2_NB_state_idle) { |
1059 | | /* g == 2 */ |
1060 | 393 | key_state->p = _libssh2_bn_init_from_bin(); /* SSH2 defined value |
1061 | | (p_value) */ |
1062 | 393 | key_state->g = _libssh2_bn_init(); /* SSH2 defined value (2) */ |
1063 | | |
1064 | | /* Initialize P and G */ |
1065 | 393 | if(!key_state->g || _libssh2_bn_set_word(key_state->g, 2)) { |
1066 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
1067 | 0 | "Failed to allocate key state g."); |
1068 | 0 | goto clean_exit; |
1069 | 0 | } |
1070 | 393 | if(!key_state->p || _libssh2_bn_from_bin(key_state->p, 128, p_value)) { |
1071 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
1072 | 0 | "Failed to allocate key state p."); |
1073 | 0 | goto clean_exit; |
1074 | 0 | } |
1075 | | |
1076 | 393 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
1077 | 393 | "Initiating Diffie-Hellman Group1 Key Exchange")); |
1078 | | |
1079 | 393 | key_state->state = libssh2_NB_state_created; |
1080 | 393 | } |
1081 | | |
1082 | 393 | ret = diffie_hellman_sha_algo(session, key_state->g, key_state->p, 128, 1, |
1083 | 393 | (void *)&exchange_hash_ctx, |
1084 | 393 | SSH_MSG_KEXDH_INIT, SSH_MSG_KEXDH_REPLY, |
1085 | 393 | NULL, 0, &key_state->exchange_state); |
1086 | 393 | if(ret == LIBSSH2_ERROR_EAGAIN) { |
1087 | 0 | return ret; |
1088 | 0 | } |
1089 | | |
1090 | 393 | clean_exit: |
1091 | 393 | kex_diffie_hellman_cleanup(session, key_state); |
1092 | | |
1093 | 393 | return ret; |
1094 | 393 | } |
1095 | | |
1096 | | |
1097 | | /* kex_method_diffie_hellman_group14_key_exchange |
1098 | | * Diffie-Hellman Group14 Key Exchange with hash function callback |
1099 | | */ |
1100 | | typedef int (*diffie_hellman_hash_func_t)(LIBSSH2_SESSION *, |
1101 | | _libssh2_bn *, |
1102 | | _libssh2_bn *, |
1103 | | int, |
1104 | | int, |
1105 | | void *, |
1106 | | unsigned char, |
1107 | | unsigned char, |
1108 | | unsigned char *, |
1109 | | size_t, |
1110 | | kmdhgGPshakex_state_t *); |
1111 | | static int |
1112 | | kex_method_diffie_hellman_group14_key_exchange(LIBSSH2_SESSION *session, |
1113 | | key_exchange_state_low_t |
1114 | | * key_state, |
1115 | | int sha_algo_value, |
1116 | | void *exchange_hash_ctx, |
1117 | | diffie_hellman_hash_func_t |
1118 | | hashfunc) |
1119 | 265 | { |
1120 | 265 | static const unsigned char p_value[256] = { |
1121 | 265 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
1122 | 265 | 0xC9, 0x0F, 0xDA, 0xA2, 0x21, 0x68, 0xC2, 0x34, |
1123 | 265 | 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1, |
1124 | 265 | 0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, |
1125 | 265 | 0x02, 0x0B, 0xBE, 0xA6, 0x3B, 0x13, 0x9B, 0x22, |
1126 | 265 | 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD, |
1127 | 265 | 0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, |
1128 | 265 | 0x30, 0x2B, 0x0A, 0x6D, 0xF2, 0x5F, 0x14, 0x37, |
1129 | 265 | 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45, |
1130 | 265 | 0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, |
1131 | 265 | 0xF4, 0x4C, 0x42, 0xE9, 0xA6, 0x37, 0xED, 0x6B, |
1132 | 265 | 0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED, |
1133 | 265 | 0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5, |
1134 | 265 | 0xAE, 0x9F, 0x24, 0x11, 0x7C, 0x4B, 0x1F, 0xE6, |
1135 | 265 | 0x49, 0x28, 0x66, 0x51, 0xEC, 0xE4, 0x5B, 0x3D, |
1136 | 265 | 0xC2, 0x00, 0x7C, 0xB8, 0xA1, 0x63, 0xBF, 0x05, |
1137 | 265 | 0x98, 0xDA, 0x48, 0x36, 0x1C, 0x55, 0xD3, 0x9A, |
1138 | 265 | 0x69, 0x16, 0x3F, 0xA8, 0xFD, 0x24, 0xCF, 0x5F, |
1139 | 265 | 0x83, 0x65, 0x5D, 0x23, 0xDC, 0xA3, 0xAD, 0x96, |
1140 | 265 | 0x1C, 0x62, 0xF3, 0x56, 0x20, 0x85, 0x52, 0xBB, |
1141 | 265 | 0x9E, 0xD5, 0x29, 0x07, 0x70, 0x96, 0x96, 0x6D, |
1142 | 265 | 0x67, 0x0C, 0x35, 0x4E, 0x4A, 0xBC, 0x98, 0x04, |
1143 | 265 | 0xF1, 0x74, 0x6C, 0x08, 0xCA, 0x18, 0x21, 0x7C, |
1144 | 265 | 0x32, 0x90, 0x5E, 0x46, 0x2E, 0x36, 0xCE, 0x3B, |
1145 | 265 | 0xE3, 0x9E, 0x77, 0x2C, 0x18, 0x0E, 0x86, 0x03, |
1146 | 265 | 0x9B, 0x27, 0x83, 0xA2, 0xEC, 0x07, 0xA2, 0x8F, |
1147 | 265 | 0xB5, 0xC5, 0x5D, 0xF0, 0x6F, 0x4C, 0x52, 0xC9, |
1148 | 265 | 0xDE, 0x2B, 0xCB, 0xF6, 0x95, 0x58, 0x17, 0x18, |
1149 | 265 | 0x39, 0x95, 0x49, 0x7C, 0xEA, 0x95, 0x6A, 0xE5, |
1150 | 265 | 0x15, 0xD2, 0x26, 0x18, 0x98, 0xFA, 0x05, 0x10, |
1151 | 265 | 0x15, 0x72, 0x8E, 0x5A, 0x8A, 0xAC, 0xAA, 0x68, |
1152 | 265 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF |
1153 | 265 | }; |
1154 | 265 | int ret; |
1155 | | |
1156 | 265 | if(key_state->state == libssh2_NB_state_idle) { |
1157 | 265 | key_state->p = _libssh2_bn_init_from_bin(); /* SSH2 defined value |
1158 | | (p_value) */ |
1159 | 265 | key_state->g = _libssh2_bn_init(); /* SSH2 defined value (2) */ |
1160 | | |
1161 | | /* g == 2 */ |
1162 | | /* Initialize P and G */ |
1163 | 265 | if(!key_state->g || _libssh2_bn_set_word(key_state->g, 2)) { |
1164 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
1165 | 0 | "Failed to allocate key state g."); |
1166 | 0 | goto clean_exit; |
1167 | 0 | } |
1168 | 265 | else if(!key_state->p || |
1169 | 265 | _libssh2_bn_from_bin(key_state->p, 256, p_value)) { |
1170 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
1171 | 0 | "Failed to allocate key state p."); |
1172 | 0 | goto clean_exit; |
1173 | 0 | } |
1174 | | |
1175 | 265 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
1176 | 265 | "Initiating Diffie-Hellman Group14 Key Exchange")); |
1177 | | |
1178 | 265 | key_state->state = libssh2_NB_state_created; |
1179 | 265 | } |
1180 | 265 | ret = hashfunc(session, key_state->g, key_state->p, |
1181 | 265 | 256, sha_algo_value, exchange_hash_ctx, SSH_MSG_KEXDH_INIT, |
1182 | 265 | SSH_MSG_KEXDH_REPLY, NULL, 0, &key_state->exchange_state); |
1183 | 265 | if(ret == LIBSSH2_ERROR_EAGAIN) { |
1184 | 0 | return ret; |
1185 | 0 | } |
1186 | | |
1187 | 265 | clean_exit: |
1188 | 265 | kex_diffie_hellman_cleanup(session, key_state); |
1189 | | |
1190 | 265 | return ret; |
1191 | 265 | } |
1192 | | |
1193 | | |
1194 | | |
1195 | | /* kex_method_diffie_hellman_group14_sha1_key_exchange |
1196 | | * Diffie-Hellman Group14 Key Exchange using SHA1 |
1197 | | */ |
1198 | | static int |
1199 | | kex_method_diffie_hellman_group14_sha1_key_exchange(LIBSSH2_SESSION *session, |
1200 | | key_exchange_state_low_t |
1201 | | * key_state) |
1202 | 264 | { |
1203 | 264 | libssh2_sha1_ctx ctx; |
1204 | 264 | return kex_method_diffie_hellman_group14_key_exchange(session, |
1205 | 264 | key_state, 1, |
1206 | 264 | &ctx, |
1207 | 264 | diffie_hellman_sha_algo); |
1208 | 264 | } |
1209 | | |
1210 | | |
1211 | | |
1212 | | /* kex_method_diffie_hellman_group14_sha256_key_exchange |
1213 | | * Diffie-Hellman Group14 Key Exchange using SHA256 |
1214 | | */ |
1215 | | static int |
1216 | | kex_method_diffie_hellman_group14_sha256_key_exchange(LIBSSH2_SESSION *session, |
1217 | | key_exchange_state_low_t |
1218 | | * key_state) |
1219 | 1 | { |
1220 | 1 | libssh2_sha256_ctx ctx; |
1221 | 1 | return kex_method_diffie_hellman_group14_key_exchange(session, |
1222 | 1 | key_state, 256, |
1223 | 1 | &ctx, |
1224 | 1 | diffie_hellman_sha_algo); |
1225 | 1 | } |
1226 | | |
1227 | | /* kex_method_diffie_hellman_group16_sha512_key_exchange |
1228 | | * Diffie-Hellman Group16 Key Exchange using SHA512 |
1229 | | */ |
1230 | | static int |
1231 | | kex_method_diffie_hellman_group16_sha512_key_exchange(LIBSSH2_SESSION *session, |
1232 | | key_exchange_state_low_t |
1233 | | * key_state) |
1234 | 154 | { |
1235 | 154 | static const unsigned char p_value[512] = { |
1236 | 154 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2, |
1237 | 154 | 0x21, 0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1, |
1238 | 154 | 0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6, |
1239 | 154 | 0x3B, 0x13, 0x9B, 0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD, |
1240 | 154 | 0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D, |
1241 | 154 | 0xF2, 0x5F, 0x14, 0x37, 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45, |
1242 | 154 | 0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9, |
1243 | 154 | 0xA6, 0x37, 0xED, 0x6B, 0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED, |
1244 | 154 | 0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5, 0xAE, 0x9F, 0x24, 0x11, |
1245 | 154 | 0x7C, 0x4B, 0x1F, 0xE6, 0x49, 0x28, 0x66, 0x51, 0xEC, 0xE4, 0x5B, 0x3D, |
1246 | 154 | 0xC2, 0x00, 0x7C, 0xB8, 0xA1, 0x63, 0xBF, 0x05, 0x98, 0xDA, 0x48, 0x36, |
1247 | 154 | 0x1C, 0x55, 0xD3, 0x9A, 0x69, 0x16, 0x3F, 0xA8, 0xFD, 0x24, 0xCF, 0x5F, |
1248 | 154 | 0x83, 0x65, 0x5D, 0x23, 0xDC, 0xA3, 0xAD, 0x96, 0x1C, 0x62, 0xF3, 0x56, |
1249 | 154 | 0x20, 0x85, 0x52, 0xBB, 0x9E, 0xD5, 0x29, 0x07, 0x70, 0x96, 0x96, 0x6D, |
1250 | 154 | 0x67, 0x0C, 0x35, 0x4E, 0x4A, 0xBC, 0x98, 0x04, 0xF1, 0x74, 0x6C, 0x08, |
1251 | 154 | 0xCA, 0x18, 0x21, 0x7C, 0x32, 0x90, 0x5E, 0x46, 0x2E, 0x36, 0xCE, 0x3B, |
1252 | 154 | 0xE3, 0x9E, 0x77, 0x2C, 0x18, 0x0E, 0x86, 0x03, 0x9B, 0x27, 0x83, 0xA2, |
1253 | 154 | 0xEC, 0x07, 0xA2, 0x8F, 0xB5, 0xC5, 0x5D, 0xF0, 0x6F, 0x4C, 0x52, 0xC9, |
1254 | 154 | 0xDE, 0x2B, 0xCB, 0xF6, 0x95, 0x58, 0x17, 0x18, 0x39, 0x95, 0x49, 0x7C, |
1255 | 154 | 0xEA, 0x95, 0x6A, 0xE5, 0x15, 0xD2, 0x26, 0x18, 0x98, 0xFA, 0x05, 0x10, |
1256 | 154 | 0x15, 0x72, 0x8E, 0x5A, 0x8A, 0xAA, 0xC4, 0x2D, 0xAD, 0x33, 0x17, 0x0D, |
1257 | 154 | 0x04, 0x50, 0x7A, 0x33, 0xA8, 0x55, 0x21, 0xAB, 0xDF, 0x1C, 0xBA, 0x64, |
1258 | 154 | 0xEC, 0xFB, 0x85, 0x04, 0x58, 0xDB, 0xEF, 0x0A, 0x8A, 0xEA, 0x71, 0x57, |
1259 | 154 | 0x5D, 0x06, 0x0C, 0x7D, 0xB3, 0x97, 0x0F, 0x85, 0xA6, 0xE1, 0xE4, 0xC7, |
1260 | 154 | 0xAB, 0xF5, 0xAE, 0x8C, 0xDB, 0x09, 0x33, 0xD7, 0x1E, 0x8C, 0x94, 0xE0, |
1261 | 154 | 0x4A, 0x25, 0x61, 0x9D, 0xCE, 0xE3, 0xD2, 0x26, 0x1A, 0xD2, 0xEE, 0x6B, |
1262 | 154 | 0xF1, 0x2F, 0xFA, 0x06, 0xD9, 0x8A, 0x08, 0x64, 0xD8, 0x76, 0x02, 0x73, |
1263 | 154 | 0x3E, 0xC8, 0x6A, 0x64, 0x52, 0x1F, 0x2B, 0x18, 0x17, 0x7B, 0x20, 0x0C, |
1264 | 154 | 0xBB, 0xE1, 0x17, 0x57, 0x7A, 0x61, 0x5D, 0x6C, 0x77, 0x09, 0x88, 0xC0, |
1265 | 154 | 0xBA, 0xD9, 0x46, 0xE2, 0x08, 0xE2, 0x4F, 0xA0, 0x74, 0xE5, 0xAB, 0x31, |
1266 | 154 | 0x43, 0xDB, 0x5B, 0xFC, 0xE0, 0xFD, 0x10, 0x8E, 0x4B, 0x82, 0xD1, 0x20, |
1267 | 154 | 0xA9, 0x21, 0x08, 0x01, 0x1A, 0x72, 0x3C, 0x12, 0xA7, 0x87, 0xE6, 0xD7, |
1268 | 154 | 0x88, 0x71, 0x9A, 0x10, 0xBD, 0xBA, 0x5B, 0x26, 0x99, 0xC3, 0x27, 0x18, |
1269 | 154 | 0x6A, 0xF4, 0xE2, 0x3C, 0x1A, 0x94, 0x68, 0x34, 0xB6, 0x15, 0x0B, 0xDA, |
1270 | 154 | 0x25, 0x83, 0xE9, 0xCA, 0x2A, 0xD4, 0x4C, 0xE8, 0xDB, 0xBB, 0xC2, 0xDB, |
1271 | 154 | 0x04, 0xDE, 0x8E, 0xF9, 0x2E, 0x8E, 0xFC, 0x14, 0x1F, 0xBE, 0xCA, 0xA6, |
1272 | 154 | 0x28, 0x7C, 0x59, 0x47, 0x4E, 0x6B, 0xC0, 0x5D, 0x99, 0xB2, 0x96, 0x4F, |
1273 | 154 | 0xA0, 0x90, 0xC3, 0xA2, 0x23, 0x3B, 0xA1, 0x86, 0x51, 0x5B, 0xE7, 0xED, |
1274 | 154 | 0x1F, 0x61, 0x29, 0x70, 0xCE, 0xE2, 0xD7, 0xAF, 0xB8, 0x1B, 0xDD, 0x76, |
1275 | 154 | 0x21, 0x70, 0x48, 0x1C, 0xD0, 0x06, 0x91, 0x27, 0xD5, 0xB0, 0x5A, 0xA9, |
1276 | 154 | 0x93, 0xB4, 0xEA, 0x98, 0x8D, 0x8F, 0xDD, 0xC1, 0x86, 0xFF, 0xB7, 0xDC, |
1277 | 154 | 0x90, 0xA6, 0xC0, 0x8F, 0x4D, 0xF4, 0x35, 0xC9, 0x34, 0x06, 0x31, 0x99, |
1278 | 154 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF |
1279 | 154 | }; |
1280 | 154 | int ret; |
1281 | 154 | libssh2_sha512_ctx exchange_hash_ctx; |
1282 | | |
1283 | 154 | if(key_state->state == libssh2_NB_state_idle) { |
1284 | 154 | key_state->p = _libssh2_bn_init_from_bin(); /* SSH2 defined value |
1285 | | (p_value) */ |
1286 | 154 | key_state->g = _libssh2_bn_init(); /* SSH2 defined value (2) */ |
1287 | | |
1288 | | /* g == 2 */ |
1289 | | /* Initialize P and G */ |
1290 | 154 | if(!key_state->g || _libssh2_bn_set_word(key_state->g, 2)) { |
1291 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
1292 | 0 | "Failed to allocate key state g."); |
1293 | 0 | goto clean_exit; |
1294 | 0 | } |
1295 | 154 | if(!key_state->p || _libssh2_bn_from_bin(key_state->p, 512, p_value)) { |
1296 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
1297 | 0 | "Failed to allocate key state p."); |
1298 | 0 | goto clean_exit; |
1299 | 0 | } |
1300 | | |
1301 | 154 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
1302 | 154 | "Initiating Diffie-Hellman Group16 Key Exchange")); |
1303 | | |
1304 | 154 | key_state->state = libssh2_NB_state_created; |
1305 | 154 | } |
1306 | | |
1307 | 154 | ret = diffie_hellman_sha_algo(session, key_state->g, key_state->p, 512, |
1308 | 154 | 512, (void *)&exchange_hash_ctx, |
1309 | 154 | SSH_MSG_KEXDH_INIT, SSH_MSG_KEXDH_REPLY, |
1310 | 154 | NULL, 0, &key_state->exchange_state); |
1311 | 154 | if(ret == LIBSSH2_ERROR_EAGAIN) { |
1312 | 0 | return ret; |
1313 | 0 | } |
1314 | | |
1315 | 154 | clean_exit: |
1316 | 154 | kex_diffie_hellman_cleanup(session, key_state); |
1317 | | |
1318 | 154 | return ret; |
1319 | 154 | } |
1320 | | |
1321 | | /* kex_method_diffie_hellman_group16_sha512_key_exchange |
1322 | | * Diffie-Hellman Group18 Key Exchange using SHA512 |
1323 | | */ |
1324 | | static int |
1325 | | kex_method_diffie_hellman_group18_sha512_key_exchange(LIBSSH2_SESSION *session, |
1326 | | key_exchange_state_low_t |
1327 | | * key_state) |
1328 | 154 | { |
1329 | 154 | static const unsigned char p_value[1024] = { |
1330 | 154 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2, |
1331 | 154 | 0x21, 0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1, |
1332 | 154 | 0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6, |
1333 | 154 | 0x3B, 0x13, 0x9B, 0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD, |
1334 | 154 | 0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D, |
1335 | 154 | 0xF2, 0x5F, 0x14, 0x37, 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45, |
1336 | 154 | 0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9, |
1337 | 154 | 0xA6, 0x37, 0xED, 0x6B, 0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED, |
1338 | 154 | 0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5, 0xAE, 0x9F, 0x24, 0x11, |
1339 | 154 | 0x7C, 0x4B, 0x1F, 0xE6, 0x49, 0x28, 0x66, 0x51, 0xEC, 0xE4, 0x5B, 0x3D, |
1340 | 154 | 0xC2, 0x00, 0x7C, 0xB8, 0xA1, 0x63, 0xBF, 0x05, 0x98, 0xDA, 0x48, 0x36, |
1341 | 154 | 0x1C, 0x55, 0xD3, 0x9A, 0x69, 0x16, 0x3F, 0xA8, 0xFD, 0x24, 0xCF, 0x5F, |
1342 | 154 | 0x83, 0x65, 0x5D, 0x23, 0xDC, 0xA3, 0xAD, 0x96, 0x1C, 0x62, 0xF3, 0x56, |
1343 | 154 | 0x20, 0x85, 0x52, 0xBB, 0x9E, 0xD5, 0x29, 0x07, 0x70, 0x96, 0x96, 0x6D, |
1344 | 154 | 0x67, 0x0C, 0x35, 0x4E, 0x4A, 0xBC, 0x98, 0x04, 0xF1, 0x74, 0x6C, 0x08, |
1345 | 154 | 0xCA, 0x18, 0x21, 0x7C, 0x32, 0x90, 0x5E, 0x46, 0x2E, 0x36, 0xCE, 0x3B, |
1346 | 154 | 0xE3, 0x9E, 0x77, 0x2C, 0x18, 0x0E, 0x86, 0x03, 0x9B, 0x27, 0x83, 0xA2, |
1347 | 154 | 0xEC, 0x07, 0xA2, 0x8F, 0xB5, 0xC5, 0x5D, 0xF0, 0x6F, 0x4C, 0x52, 0xC9, |
1348 | 154 | 0xDE, 0x2B, 0xCB, 0xF6, 0x95, 0x58, 0x17, 0x18, 0x39, 0x95, 0x49, 0x7C, |
1349 | 154 | 0xEA, 0x95, 0x6A, 0xE5, 0x15, 0xD2, 0x26, 0x18, 0x98, 0xFA, 0x05, 0x10, |
1350 | 154 | 0x15, 0x72, 0x8E, 0x5A, 0x8A, 0xAA, 0xC4, 0x2D, 0xAD, 0x33, 0x17, 0x0D, |
1351 | 154 | 0x04, 0x50, 0x7A, 0x33, 0xA8, 0x55, 0x21, 0xAB, 0xDF, 0x1C, 0xBA, 0x64, |
1352 | 154 | 0xEC, 0xFB, 0x85, 0x04, 0x58, 0xDB, 0xEF, 0x0A, 0x8A, 0xEA, 0x71, 0x57, |
1353 | 154 | 0x5D, 0x06, 0x0C, 0x7D, 0xB3, 0x97, 0x0F, 0x85, 0xA6, 0xE1, 0xE4, 0xC7, |
1354 | 154 | 0xAB, 0xF5, 0xAE, 0x8C, 0xDB, 0x09, 0x33, 0xD7, 0x1E, 0x8C, 0x94, 0xE0, |
1355 | 154 | 0x4A, 0x25, 0x61, 0x9D, 0xCE, 0xE3, 0xD2, 0x26, 0x1A, 0xD2, 0xEE, 0x6B, |
1356 | 154 | 0xF1, 0x2F, 0xFA, 0x06, 0xD9, 0x8A, 0x08, 0x64, 0xD8, 0x76, 0x02, 0x73, |
1357 | 154 | 0x3E, 0xC8, 0x6A, 0x64, 0x52, 0x1F, 0x2B, 0x18, 0x17, 0x7B, 0x20, 0x0C, |
1358 | 154 | 0xBB, 0xE1, 0x17, 0x57, 0x7A, 0x61, 0x5D, 0x6C, 0x77, 0x09, 0x88, 0xC0, |
1359 | 154 | 0xBA, 0xD9, 0x46, 0xE2, 0x08, 0xE2, 0x4F, 0xA0, 0x74, 0xE5, 0xAB, 0x31, |
1360 | 154 | 0x43, 0xDB, 0x5B, 0xFC, 0xE0, 0xFD, 0x10, 0x8E, 0x4B, 0x82, 0xD1, 0x20, |
1361 | 154 | 0xA9, 0x21, 0x08, 0x01, 0x1A, 0x72, 0x3C, 0x12, 0xA7, 0x87, 0xE6, 0xD7, |
1362 | 154 | 0x88, 0x71, 0x9A, 0x10, 0xBD, 0xBA, 0x5B, 0x26, 0x99, 0xC3, 0x27, 0x18, |
1363 | 154 | 0x6A, 0xF4, 0xE2, 0x3C, 0x1A, 0x94, 0x68, 0x34, 0xB6, 0x15, 0x0B, 0xDA, |
1364 | 154 | 0x25, 0x83, 0xE9, 0xCA, 0x2A, 0xD4, 0x4C, 0xE8, 0xDB, 0xBB, 0xC2, 0xDB, |
1365 | 154 | 0x04, 0xDE, 0x8E, 0xF9, 0x2E, 0x8E, 0xFC, 0x14, 0x1F, 0xBE, 0xCA, 0xA6, |
1366 | 154 | 0x28, 0x7C, 0x59, 0x47, 0x4E, 0x6B, 0xC0, 0x5D, 0x99, 0xB2, 0x96, 0x4F, |
1367 | 154 | 0xA0, 0x90, 0xC3, 0xA2, 0x23, 0x3B, 0xA1, 0x86, 0x51, 0x5B, 0xE7, 0xED, |
1368 | 154 | 0x1F, 0x61, 0x29, 0x70, 0xCE, 0xE2, 0xD7, 0xAF, 0xB8, 0x1B, 0xDD, 0x76, |
1369 | 154 | 0x21, 0x70, 0x48, 0x1C, 0xD0, 0x06, 0x91, 0x27, 0xD5, 0xB0, 0x5A, 0xA9, |
1370 | 154 | 0x93, 0xB4, 0xEA, 0x98, 0x8D, 0x8F, 0xDD, 0xC1, 0x86, 0xFF, 0xB7, 0xDC, |
1371 | 154 | 0x90, 0xA6, 0xC0, 0x8F, 0x4D, 0xF4, 0x35, 0xC9, 0x34, 0x02, 0x84, 0x92, |
1372 | 154 | 0x36, 0xC3, 0xFA, 0xB4, 0xD2, 0x7C, 0x70, 0x26, 0xC1, 0xD4, 0xDC, 0xB2, |
1373 | 154 | 0x60, 0x26, 0x46, 0xDE, 0xC9, 0x75, 0x1E, 0x76, 0x3D, 0xBA, 0x37, 0xBD, |
1374 | 154 | 0xF8, 0xFF, 0x94, 0x06, 0xAD, 0x9E, 0x53, 0x0E, 0xE5, 0xDB, 0x38, 0x2F, |
1375 | 154 | 0x41, 0x30, 0x01, 0xAE, 0xB0, 0x6A, 0x53, 0xED, 0x90, 0x27, 0xD8, 0x31, |
1376 | 154 | 0x17, 0x97, 0x27, 0xB0, 0x86, 0x5A, 0x89, 0x18, 0xDA, 0x3E, 0xDB, 0xEB, |
1377 | 154 | 0xCF, 0x9B, 0x14, 0xED, 0x44, 0xCE, 0x6C, 0xBA, 0xCE, 0xD4, 0xBB, 0x1B, |
1378 | 154 | 0xDB, 0x7F, 0x14, 0x47, 0xE6, 0xCC, 0x25, 0x4B, 0x33, 0x20, 0x51, 0x51, |
1379 | 154 | 0x2B, 0xD7, 0xAF, 0x42, 0x6F, 0xB8, 0xF4, 0x01, 0x37, 0x8C, 0xD2, 0xBF, |
1380 | 154 | 0x59, 0x83, 0xCA, 0x01, 0xC6, 0x4B, 0x92, 0xEC, 0xF0, 0x32, 0xEA, 0x15, |
1381 | 154 | 0xD1, 0x72, 0x1D, 0x03, 0xF4, 0x82, 0xD7, 0xCE, 0x6E, 0x74, 0xFE, 0xF6, |
1382 | 154 | 0xD5, 0x5E, 0x70, 0x2F, 0x46, 0x98, 0x0C, 0x82, 0xB5, 0xA8, 0x40, 0x31, |
1383 | 154 | 0x90, 0x0B, 0x1C, 0x9E, 0x59, 0xE7, 0xC9, 0x7F, 0xBE, 0xC7, 0xE8, 0xF3, |
1384 | 154 | 0x23, 0xA9, 0x7A, 0x7E, 0x36, 0xCC, 0x88, 0xBE, 0x0F, 0x1D, 0x45, 0xB7, |
1385 | 154 | 0xFF, 0x58, 0x5A, 0xC5, 0x4B, 0xD4, 0x07, 0xB2, 0x2B, 0x41, 0x54, 0xAA, |
1386 | 154 | 0xCC, 0x8F, 0x6D, 0x7E, 0xBF, 0x48, 0xE1, 0xD8, 0x14, 0xCC, 0x5E, 0xD2, |
1387 | 154 | 0x0F, 0x80, 0x37, 0xE0, 0xA7, 0x97, 0x15, 0xEE, 0xF2, 0x9B, 0xE3, 0x28, |
1388 | 154 | 0x06, 0xA1, 0xD5, 0x8B, 0xB7, 0xC5, 0xDA, 0x76, 0xF5, 0x50, 0xAA, 0x3D, |
1389 | 154 | 0x8A, 0x1F, 0xBF, 0xF0, 0xEB, 0x19, 0xCC, 0xB1, 0xA3, 0x13, 0xD5, 0x5C, |
1390 | 154 | 0xDA, 0x56, 0xC9, 0xEC, 0x2E, 0xF2, 0x96, 0x32, 0x38, 0x7F, 0xE8, 0xD7, |
1391 | 154 | 0x6E, 0x3C, 0x04, 0x68, 0x04, 0x3E, 0x8F, 0x66, 0x3F, 0x48, 0x60, 0xEE, |
1392 | 154 | 0x12, 0xBF, 0x2D, 0x5B, 0x0B, 0x74, 0x74, 0xD6, 0xE6, 0x94, 0xF9, 0x1E, |
1393 | 154 | 0x6D, 0xBE, 0x11, 0x59, 0x74, 0xA3, 0x92, 0x6F, 0x12, 0xFE, 0xE5, 0xE4, |
1394 | 154 | 0x38, 0x77, 0x7C, 0xB6, 0xA9, 0x32, 0xDF, 0x8C, 0xD8, 0xBE, 0xC4, 0xD0, |
1395 | 154 | 0x73, 0xB9, 0x31, 0xBA, 0x3B, 0xC8, 0x32, 0xB6, 0x8D, 0x9D, 0xD3, 0x00, |
1396 | 154 | 0x74, 0x1F, 0xA7, 0xBF, 0x8A, 0xFC, 0x47, 0xED, 0x25, 0x76, 0xF6, 0x93, |
1397 | 154 | 0x6B, 0xA4, 0x24, 0x66, 0x3A, 0xAB, 0x63, 0x9C, 0x5A, 0xE4, 0xF5, 0x68, |
1398 | 154 | 0x34, 0x23, 0xB4, 0x74, 0x2B, 0xF1, 0xC9, 0x78, 0x23, 0x8F, 0x16, 0xCB, |
1399 | 154 | 0xE3, 0x9D, 0x65, 0x2D, 0xE3, 0xFD, 0xB8, 0xBE, 0xFC, 0x84, 0x8A, 0xD9, |
1400 | 154 | 0x22, 0x22, 0x2E, 0x04, 0xA4, 0x03, 0x7C, 0x07, 0x13, 0xEB, 0x57, 0xA8, |
1401 | 154 | 0x1A, 0x23, 0xF0, 0xC7, 0x34, 0x73, 0xFC, 0x64, 0x6C, 0xEA, 0x30, 0x6B, |
1402 | 154 | 0x4B, 0xCB, 0xC8, 0x86, 0x2F, 0x83, 0x85, 0xDD, 0xFA, 0x9D, 0x4B, 0x7F, |
1403 | 154 | 0xA2, 0xC0, 0x87, 0xE8, 0x79, 0x68, 0x33, 0x03, 0xED, 0x5B, 0xDD, 0x3A, |
1404 | 154 | 0x06, 0x2B, 0x3C, 0xF5, 0xB3, 0xA2, 0x78, 0xA6, 0x6D, 0x2A, 0x13, 0xF8, |
1405 | 154 | 0x3F, 0x44, 0xF8, 0x2D, 0xDF, 0x31, 0x0E, 0xE0, 0x74, 0xAB, 0x6A, 0x36, |
1406 | 154 | 0x45, 0x97, 0xE8, 0x99, 0xA0, 0x25, 0x5D, 0xC1, 0x64, 0xF3, 0x1C, 0xC5, |
1407 | 154 | 0x08, 0x46, 0x85, 0x1D, 0xF9, 0xAB, 0x48, 0x19, 0x5D, 0xED, 0x7E, 0xA1, |
1408 | 154 | 0xB1, 0xD5, 0x10, 0xBD, 0x7E, 0xE7, 0x4D, 0x73, 0xFA, 0xF3, 0x6B, 0xC3, |
1409 | 154 | 0x1E, 0xCF, 0xA2, 0x68, 0x35, 0x90, 0x46, 0xF4, 0xEB, 0x87, 0x9F, 0x92, |
1410 | 154 | 0x40, 0x09, 0x43, 0x8B, 0x48, 0x1C, 0x6C, 0xD7, 0x88, 0x9A, 0x00, 0x2E, |
1411 | 154 | 0xD5, 0xEE, 0x38, 0x2B, 0xC9, 0x19, 0x0D, 0xA6, 0xFC, 0x02, 0x6E, 0x47, |
1412 | 154 | 0x95, 0x58, 0xE4, 0x47, 0x56, 0x77, 0xE9, 0xAA, 0x9E, 0x30, 0x50, 0xE2, |
1413 | 154 | 0x76, 0x56, 0x94, 0xDF, 0xC8, 0x1F, 0x56, 0xE8, 0x80, 0xB9, 0x6E, 0x71, |
1414 | 154 | 0x60, 0xC9, 0x80, 0xDD, 0x98, 0xED, 0xD3, 0xDF, 0xFF, 0xFF, 0xFF, 0xFF, |
1415 | 154 | 0xFF, 0xFF, 0xFF, 0xFF |
1416 | 154 | }; |
1417 | 154 | int ret; |
1418 | 154 | libssh2_sha512_ctx exchange_hash_ctx; |
1419 | | |
1420 | 154 | if(key_state->state == libssh2_NB_state_idle) { |
1421 | 154 | key_state->p = _libssh2_bn_init_from_bin(); /* SSH2 defined value |
1422 | | (p_value) */ |
1423 | 154 | key_state->g = _libssh2_bn_init(); /* SSH2 defined value (2) */ |
1424 | | |
1425 | | /* g == 2 */ |
1426 | | /* Initialize P and G */ |
1427 | 154 | if(!key_state->g || _libssh2_bn_set_word(key_state->g, 2)) { |
1428 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
1429 | 0 | "Failed to allocate key state g."); |
1430 | 0 | goto clean_exit; |
1431 | 0 | } |
1432 | 154 | else if(!key_state->p || |
1433 | 154 | _libssh2_bn_from_bin(key_state->p, 1024, p_value)) { |
1434 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
1435 | 0 | "Failed to allocate key state p."); |
1436 | 0 | goto clean_exit; |
1437 | 0 | } |
1438 | | |
1439 | 154 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
1440 | 154 | "Initiating Diffie-Hellman Group18 Key Exchange")); |
1441 | | |
1442 | 154 | key_state->state = libssh2_NB_state_created; |
1443 | 154 | } |
1444 | | |
1445 | 154 | ret = diffie_hellman_sha_algo(session, key_state->g, key_state->p, 1024, |
1446 | 154 | 512, (void *)&exchange_hash_ctx, |
1447 | 154 | SSH_MSG_KEXDH_INIT, SSH_MSG_KEXDH_REPLY, |
1448 | 154 | NULL, 0, &key_state->exchange_state); |
1449 | 154 | if(ret == LIBSSH2_ERROR_EAGAIN) { |
1450 | 0 | return ret; |
1451 | 0 | } |
1452 | | |
1453 | 154 | clean_exit: |
1454 | 154 | kex_diffie_hellman_cleanup(session, key_state); |
1455 | | |
1456 | 154 | return ret; |
1457 | 154 | } |
1458 | | |
1459 | | /* kex_method_diffie_hellman_group_exchange_sha1_key_exchange |
1460 | | * Diffie-Hellman Group Exchange Key Exchange using SHA1 |
1461 | | * Negotiates random(ish) group for secret derivation |
1462 | | */ |
1463 | | static int |
1464 | | kex_method_diffie_hellman_group_exchange_sha1_key_exchange( |
1465 | | LIBSSH2_SESSION * session, |
1466 | | key_exchange_state_low_t * key_state) |
1467 | 37 | { |
1468 | 37 | int ret = 0; |
1469 | 37 | int rc; |
1470 | | |
1471 | 37 | if(key_state->state == libssh2_NB_state_idle) { |
1472 | 37 | key_state->p = _libssh2_bn_init_from_bin(); |
1473 | 37 | key_state->g = _libssh2_bn_init_from_bin(); |
1474 | | /* Ask for a P and G pair */ |
1475 | 37 | key_state->request[0] = SSH_MSG_KEX_DH_GEX_REQUEST; |
1476 | 37 | _libssh2_htonu32(key_state->request + 1, LIBSSH2_DH_GEX_MINGROUP); |
1477 | 37 | _libssh2_htonu32(key_state->request + 5, LIBSSH2_DH_GEX_OPTGROUP); |
1478 | 37 | _libssh2_htonu32(key_state->request + 9, LIBSSH2_DH_GEX_MAXGROUP); |
1479 | 37 | key_state->request_len = 13; |
1480 | 37 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
1481 | 37 | "Initiating Diffie-Hellman Group-Exchange SHA1")); |
1482 | | |
1483 | 37 | key_state->state = libssh2_NB_state_created; |
1484 | 37 | } |
1485 | | |
1486 | 37 | if(key_state->state == libssh2_NB_state_created) { |
1487 | 37 | rc = _libssh2_transport_send(session, key_state->request, |
1488 | 37 | key_state->request_len, NULL, 0); |
1489 | 37 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
1490 | 0 | return rc; |
1491 | 0 | } |
1492 | 37 | else if(rc) { |
1493 | 0 | ret = _libssh2_error(session, rc, |
1494 | 0 | "Unable to send Group Exchange Request"); |
1495 | 0 | goto dh_gex_clean_exit; |
1496 | 0 | } |
1497 | | |
1498 | 37 | key_state->state = libssh2_NB_state_sent; |
1499 | 37 | } |
1500 | | |
1501 | 37 | if(key_state->state == libssh2_NB_state_sent) { |
1502 | 37 | rc = _libssh2_packet_require(session, SSH_MSG_KEX_DH_GEX_GROUP, |
1503 | 37 | &key_state->data, &key_state->data_len, |
1504 | 37 | 0, NULL, 0, &key_state->req_state); |
1505 | 37 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
1506 | 0 | return rc; |
1507 | 0 | } |
1508 | 37 | else if(rc) { |
1509 | 9 | ret = _libssh2_error(session, rc, |
1510 | 9 | "Timeout waiting for GEX_GROUP reply"); |
1511 | 9 | goto dh_gex_clean_exit; |
1512 | 9 | } |
1513 | | |
1514 | 28 | key_state->state = libssh2_NB_state_sent1; |
1515 | 28 | } |
1516 | | |
1517 | 28 | if(key_state->state == libssh2_NB_state_sent1) { |
1518 | 28 | size_t p_len, g_len; |
1519 | 28 | unsigned char *p, *g; |
1520 | 28 | struct string_buf buf; |
1521 | 28 | libssh2_sha1_ctx exchange_hash_ctx; |
1522 | | |
1523 | 28 | if(key_state->data_len < 9) { |
1524 | 2 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
1525 | 2 | "Unexpected key length DH-SHA1"); |
1526 | 2 | goto dh_gex_clean_exit; |
1527 | 2 | } |
1528 | | |
1529 | 26 | buf.data = key_state->data; |
1530 | 26 | buf.dataptr = buf.data; |
1531 | 26 | buf.len = key_state->data_len; |
1532 | | |
1533 | 26 | buf.dataptr++; /* increment to big num */ |
1534 | | |
1535 | 26 | if(_libssh2_get_bignum_bytes(&buf, &p, &p_len)) { |
1536 | 3 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
1537 | 3 | "Unexpected value DH-SHA1 p"); |
1538 | 3 | goto dh_gex_clean_exit; |
1539 | 3 | } |
1540 | | |
1541 | 23 | if(_libssh2_get_bignum_bytes(&buf, &g, &g_len)) { |
1542 | 2 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
1543 | 2 | "Unexpected value DH-SHA1 g"); |
1544 | 2 | goto dh_gex_clean_exit; |
1545 | 2 | } |
1546 | | |
1547 | 21 | if(_libssh2_bn_from_bin(key_state->p, p_len, p)) { |
1548 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
1549 | 0 | "Invalid DH-SHA1 p"); |
1550 | 0 | goto dh_gex_clean_exit; |
1551 | 0 | } |
1552 | | |
1553 | 21 | if(_libssh2_bn_from_bin(key_state->g, g_len, g)) { |
1554 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
1555 | 0 | "Invalid DH-SHA1 g"); |
1556 | 0 | goto dh_gex_clean_exit; |
1557 | 0 | } |
1558 | | |
1559 | 21 | ret = diffie_hellman_sha_algo(session, key_state->g, key_state->p, |
1560 | 21 | (int)p_len, 1, |
1561 | 21 | (void *)&exchange_hash_ctx, |
1562 | 21 | SSH_MSG_KEX_DH_GEX_INIT, |
1563 | 21 | SSH_MSG_KEX_DH_GEX_REPLY, |
1564 | 21 | key_state->data + 1, |
1565 | 21 | key_state->data_len - 1, |
1566 | 21 | &key_state->exchange_state); |
1567 | 21 | if(ret == LIBSSH2_ERROR_EAGAIN) { |
1568 | 0 | return ret; |
1569 | 0 | } |
1570 | 21 | } |
1571 | | |
1572 | 37 | dh_gex_clean_exit: |
1573 | 37 | kex_diffie_hellman_cleanup(session, key_state); |
1574 | | |
1575 | 37 | return ret; |
1576 | 28 | } |
1577 | | |
1578 | | |
1579 | | |
1580 | | /* kex_method_diffie_hellman_group_exchange_sha256_key_exchange |
1581 | | * Diffie-Hellman Group Exchange Key Exchange using SHA256 |
1582 | | * Negotiates random(ish) group for secret derivation |
1583 | | */ |
1584 | | static int |
1585 | | kex_method_diffie_hellman_group_exchange_sha256_key_exchange( |
1586 | | LIBSSH2_SESSION * session, |
1587 | | key_exchange_state_low_t * key_state) |
1588 | 307 | { |
1589 | 307 | int ret = 0; |
1590 | 307 | int rc; |
1591 | | |
1592 | 307 | if(key_state->state == libssh2_NB_state_idle) { |
1593 | 307 | key_state->p = _libssh2_bn_init(); |
1594 | 307 | key_state->g = _libssh2_bn_init(); |
1595 | | /* Ask for a P and G pair */ |
1596 | 307 | key_state->request[0] = SSH_MSG_KEX_DH_GEX_REQUEST; |
1597 | 307 | _libssh2_htonu32(key_state->request + 1, LIBSSH2_DH_GEX_MINGROUP); |
1598 | 307 | _libssh2_htonu32(key_state->request + 5, LIBSSH2_DH_GEX_OPTGROUP); |
1599 | 307 | _libssh2_htonu32(key_state->request + 9, LIBSSH2_DH_GEX_MAXGROUP); |
1600 | 307 | key_state->request_len = 13; |
1601 | 307 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
1602 | 307 | "Initiating Diffie-Hellman Group-Exchange SHA256")); |
1603 | | |
1604 | 307 | key_state->state = libssh2_NB_state_created; |
1605 | 307 | } |
1606 | | |
1607 | 307 | if(key_state->state == libssh2_NB_state_created) { |
1608 | 307 | rc = _libssh2_transport_send(session, key_state->request, |
1609 | 307 | key_state->request_len, NULL, 0); |
1610 | 307 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
1611 | 0 | return rc; |
1612 | 0 | } |
1613 | 307 | else if(rc) { |
1614 | 0 | ret = _libssh2_error(session, rc, |
1615 | 0 | "Unable to send " |
1616 | 0 | "Group Exchange Request SHA256"); |
1617 | 0 | goto dh_gex_clean_exit; |
1618 | 0 | } |
1619 | | |
1620 | 307 | key_state->state = libssh2_NB_state_sent; |
1621 | 307 | } |
1622 | | |
1623 | 307 | if(key_state->state == libssh2_NB_state_sent) { |
1624 | 307 | rc = _libssh2_packet_require(session, SSH_MSG_KEX_DH_GEX_GROUP, |
1625 | 307 | &key_state->data, &key_state->data_len, |
1626 | 307 | 0, NULL, 0, &key_state->req_state); |
1627 | 307 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
1628 | 0 | return rc; |
1629 | 0 | } |
1630 | 307 | else if(rc) { |
1631 | 101 | ret = _libssh2_error(session, rc, |
1632 | 101 | "Timeout waiting for GEX_GROUP reply SHA256"); |
1633 | 101 | goto dh_gex_clean_exit; |
1634 | 101 | } |
1635 | | |
1636 | 206 | key_state->state = libssh2_NB_state_sent1; |
1637 | 206 | } |
1638 | | |
1639 | 206 | if(key_state->state == libssh2_NB_state_sent1) { |
1640 | 206 | unsigned char *p, *g; |
1641 | 206 | size_t p_len, g_len; |
1642 | 206 | struct string_buf buf; |
1643 | 206 | libssh2_sha256_ctx exchange_hash_ctx; |
1644 | | |
1645 | 206 | if(key_state->data_len < 9) { |
1646 | 3 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
1647 | 3 | "Unexpected key length DH-SHA256"); |
1648 | 3 | goto dh_gex_clean_exit; |
1649 | 3 | } |
1650 | | |
1651 | 203 | buf.data = key_state->data; |
1652 | 203 | buf.dataptr = buf.data; |
1653 | 203 | buf.len = key_state->data_len; |
1654 | | |
1655 | 203 | buf.dataptr++; /* increment to big num */ |
1656 | | |
1657 | 203 | if(_libssh2_get_bignum_bytes(&buf, &p, &p_len)) { |
1658 | 12 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
1659 | 12 | "Unexpected value DH-SHA256 p"); |
1660 | 12 | goto dh_gex_clean_exit; |
1661 | 12 | } |
1662 | | |
1663 | 191 | if(_libssh2_get_bignum_bytes(&buf, &g, &g_len)) { |
1664 | 11 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
1665 | 11 | "Unexpected value DH-SHA256 g"); |
1666 | 11 | goto dh_gex_clean_exit; |
1667 | 11 | } |
1668 | | |
1669 | 180 | if(_libssh2_bn_from_bin(key_state->p, p_len, p)) { |
1670 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
1671 | 0 | "Invalid DH-SHA256 p"); |
1672 | 0 | goto dh_gex_clean_exit; |
1673 | 0 | } |
1674 | | |
1675 | 180 | if(_libssh2_bn_from_bin(key_state->g, g_len, g)) { |
1676 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
1677 | 0 | "Invalid DH-SHA256 g"); |
1678 | 0 | goto dh_gex_clean_exit; |
1679 | 0 | } |
1680 | | |
1681 | 180 | ret = diffie_hellman_sha_algo(session, key_state->g, key_state->p, |
1682 | 180 | (int)p_len, 256, |
1683 | 180 | (void *)&exchange_hash_ctx, |
1684 | 180 | SSH_MSG_KEX_DH_GEX_INIT, |
1685 | 180 | SSH_MSG_KEX_DH_GEX_REPLY, |
1686 | 180 | key_state->data + 1, |
1687 | 180 | key_state->data_len - 1, |
1688 | 180 | &key_state->exchange_state); |
1689 | 180 | if(ret == LIBSSH2_ERROR_EAGAIN) { |
1690 | 0 | return ret; |
1691 | 0 | } |
1692 | 180 | } |
1693 | | |
1694 | 307 | dh_gex_clean_exit: |
1695 | 307 | kex_diffie_hellman_cleanup(session, key_state); |
1696 | | |
1697 | 307 | return ret; |
1698 | 206 | } |
1699 | | |
1700 | | #if LIBSSH2_ECDSA |
1701 | | |
1702 | | /* LIBSSH2_KEX_METHOD_EC_SHA_HASH_CREATE_VERIFY |
1703 | | * |
1704 | | * Macro that create and verifies EC SHA hash with a given digest bytes |
1705 | | * |
1706 | | * Payload format: |
1707 | | * |
1708 | | * string V_C, client's identification string (CR and LF excluded) |
1709 | | * string V_S, server's identification string (CR and LF excluded) |
1710 | | * string I_C, payload of the client's SSH_MSG_KEXINIT |
1711 | | * string I_S, payload of the server's SSH_MSG_KEXINIT |
1712 | | * string K_S, server's public host key |
1713 | | * string Q_C, client's ephemeral public key octet string |
1714 | | * string Q_S, server's ephemeral public key octet string |
1715 | | * mpint K, shared secret |
1716 | | * |
1717 | | */ |
1718 | 6 | #define LIBSSH2_KEX_METHOD_EC_SHA_HASH_CREATE_VERIFY(digest_type) \ |
1719 | 6 | do { \ |
1720 | 6 | libssh2_sha##digest_type##_ctx ctx; \ |
1721 | 6 | int hok; \ |
1722 | 6 | if(!libssh2_sha##digest_type##_init(&ctx)) { \ |
1723 | 0 | rc = -1; \ |
1724 | 0 | break; \ |
1725 | 0 | } \ |
1726 | 6 | exchange_state->exchange_hash = (void *)&ctx; \ |
1727 | 6 | hok = 1; \ |
1728 | 6 | if(session->local.banner) { \ |
1729 | 0 | _libssh2_htonu32(exchange_state->h_sig_comp, \ |
1730 | 0 | (uint32_t)(strlen((char *) session->local.banner) - 2)); \ |
1731 | 0 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1732 | 0 | exchange_state->h_sig_comp, \ |
1733 | 0 | 4); \ |
1734 | 0 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1735 | 0 | (char *)session->local.banner, \ |
1736 | 0 | strlen((char *)session->local.banner) \ |
1737 | 0 | - 2); \ |
1738 | 0 | } \ |
1739 | 6 | else { \ |
1740 | 6 | _libssh2_htonu32(exchange_state->h_sig_comp, \ |
1741 | 6 | sizeof(LIBSSH2_SSH_DEFAULT_BANNER) - 1); \ |
1742 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1743 | 6 | exchange_state->h_sig_comp, 4); \ |
1744 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1745 | 6 | LIBSSH2_SSH_DEFAULT_BANNER, \ |
1746 | 6 | sizeof(LIBSSH2_SSH_DEFAULT_BANNER) \ |
1747 | 6 | - 1); \ |
1748 | 6 | } \ |
1749 | 6 | \ |
1750 | 6 | _libssh2_htonu32(exchange_state->h_sig_comp, \ |
1751 | 6 | (uint32_t)strlen((char *) session->remote.banner)); \ |
1752 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1753 | 6 | exchange_state->h_sig_comp, 4); \ |
1754 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, session->remote.banner, \ |
1755 | 6 | strlen((char *)session->remote.banner)); \ |
1756 | 6 | \ |
1757 | 6 | _libssh2_htonu32(exchange_state->h_sig_comp, \ |
1758 | 6 | (uint32_t)session->local.kexinit_len); \ |
1759 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1760 | 6 | exchange_state->h_sig_comp, 4); \ |
1761 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1762 | 6 | session->local.kexinit, \ |
1763 | 6 | session->local.kexinit_len); \ |
1764 | 6 | \ |
1765 | 6 | _libssh2_htonu32(exchange_state->h_sig_comp, \ |
1766 | 6 | (uint32_t)session->remote.kexinit_len); \ |
1767 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1768 | 6 | exchange_state->h_sig_comp, 4); \ |
1769 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1770 | 6 | session->remote.kexinit, \ |
1771 | 6 | session->remote.kexinit_len); \ |
1772 | 6 | \ |
1773 | 6 | _libssh2_htonu32(exchange_state->h_sig_comp, \ |
1774 | 6 | session->server_hostkey_len); \ |
1775 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1776 | 6 | exchange_state->h_sig_comp, 4); \ |
1777 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1778 | 6 | session->server_hostkey, \ |
1779 | 6 | session->server_hostkey_len); \ |
1780 | 6 | \ |
1781 | 6 | _libssh2_htonu32(exchange_state->h_sig_comp, \ |
1782 | 6 | (uint32_t)public_key_len); \ |
1783 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1784 | 6 | exchange_state->h_sig_comp, 4); \ |
1785 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1786 | 6 | public_key, \ |
1787 | 6 | public_key_len); \ |
1788 | 6 | \ |
1789 | 6 | _libssh2_htonu32(exchange_state->h_sig_comp, \ |
1790 | 6 | (uint32_t)server_public_key_len); \ |
1791 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1792 | 6 | exchange_state->h_sig_comp, 4); \ |
1793 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1794 | 6 | server_public_key, \ |
1795 | 6 | server_public_key_len); \ |
1796 | 6 | \ |
1797 | 6 | hok &= libssh2_sha##digest_type##_update(ctx, \ |
1798 | 6 | exchange_state->k_value, \ |
1799 | 6 | exchange_state->k_value_len); \ |
1800 | 6 | \ |
1801 | 6 | if(!hok || \ |
1802 | 6 | !libssh2_sha##digest_type##_final(ctx, exchange_state->h_sig_comp)) { \ |
1803 | 0 | rc = -1; \ |
1804 | 0 | break; \ |
1805 | 0 | } \ |
1806 | 6 | \ |
1807 | 6 | if(session->hostkey-> \ |
1808 | 6 | sig_verify(session, exchange_state->h_sig, \ |
1809 | 6 | exchange_state->h_sig_len, exchange_state->h_sig_comp, \ |
1810 | 6 | SHA##digest_type##_DIGEST_LENGTH, \ |
1811 | 6 | &session->server_hostkey_abstract)) { \ |
1812 | 6 | rc = -1; \ |
1813 | 6 | } \ |
1814 | 6 | } while(0) |
1815 | | |
1816 | | /* kex_session_ecdh_curve_type |
1817 | | * returns the EC curve type by name used in key exchange |
1818 | | */ |
1819 | | |
1820 | | static int |
1821 | | kex_session_ecdh_curve_type(const char *name, libssh2_curve_type *out_type) |
1822 | 392 | { |
1823 | 392 | libssh2_curve_type type; |
1824 | | |
1825 | 392 | if(!name) |
1826 | 0 | return -1; |
1827 | | |
1828 | 392 | if(strcmp(name, "ecdh-sha2-nistp256") == 0) |
1829 | 121 | type = LIBSSH2_EC_CURVE_NISTP256; |
1830 | 271 | else if(strcmp(name, "ecdh-sha2-nistp384") == 0) |
1831 | 40 | type = LIBSSH2_EC_CURVE_NISTP384; |
1832 | 231 | else if(strcmp(name, "ecdh-sha2-nistp521") == 0) |
1833 | 231 | type = LIBSSH2_EC_CURVE_NISTP521; |
1834 | 0 | else { |
1835 | 0 | return -1; |
1836 | 0 | } |
1837 | | |
1838 | 392 | if(out_type) { |
1839 | 392 | *out_type = type; |
1840 | 392 | } |
1841 | | |
1842 | 392 | return 0; |
1843 | 392 | } |
1844 | | |
1845 | | |
1846 | | static void |
1847 | | ecdh_exchange_state_cleanup(LIBSSH2_SESSION * session, |
1848 | | kmdhgGPshakex_state_t *exchange_state) |
1849 | 156 | { |
1850 | 156 | _libssh2_bn_free(exchange_state->k); |
1851 | 156 | exchange_state->k = NULL; |
1852 | | |
1853 | 156 | if(exchange_state->k_value) { |
1854 | 0 | LIBSSH2_FREE(session, exchange_state->k_value); |
1855 | 0 | exchange_state->k_value = NULL; |
1856 | 0 | } |
1857 | | |
1858 | 156 | exchange_state->state = libssh2_NB_state_idle; |
1859 | 156 | } |
1860 | | |
1861 | | |
1862 | | static void |
1863 | | kex_method_ecdh_cleanup |
1864 | | (LIBSSH2_SESSION * session, key_exchange_state_low_t * key_state) |
1865 | 580 | { |
1866 | 580 | if(key_state->public_key_oct) { |
1867 | 233 | LIBSSH2_FREE(session, key_state->public_key_oct); |
1868 | 233 | key_state->public_key_oct = NULL; |
1869 | 233 | } |
1870 | | |
1871 | 580 | if(key_state->private_key) { |
1872 | 233 | _libssh2_ecdsa_free(key_state->private_key); |
1873 | 233 | key_state->private_key = NULL; |
1874 | 233 | } |
1875 | | |
1876 | 580 | if(key_state->data) { |
1877 | 159 | LIBSSH2_FREE(session, key_state->data); |
1878 | 159 | key_state->data = NULL; |
1879 | 159 | } |
1880 | | |
1881 | 580 | key_state->state = libssh2_NB_state_idle; |
1882 | | |
1883 | 580 | if(key_state->exchange_state.state != libssh2_NB_state_idle) { |
1884 | 0 | ecdh_exchange_state_cleanup(session, &key_state->exchange_state); |
1885 | 0 | } |
1886 | 580 | } |
1887 | | |
1888 | | |
1889 | | /* ecdh_sha2_nistp |
1890 | | * Elliptic Curve Diffie Hellman Key Exchange |
1891 | | */ |
1892 | | |
1893 | | static int ecdh_sha2_nistp(LIBSSH2_SESSION *session, libssh2_curve_type type, |
1894 | | unsigned char *data, size_t data_len, |
1895 | | unsigned char *public_key, |
1896 | | size_t public_key_len, _libssh2_ec_key *private_key, |
1897 | | kmdhgGPshakex_state_t *exchange_state) |
1898 | 159 | { |
1899 | 159 | int ret = 0; |
1900 | 159 | int rc; |
1901 | | |
1902 | 159 | if(data_len < 5) { |
1903 | 3 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, |
1904 | 3 | "Host key data is too short"); |
1905 | 3 | return ret; |
1906 | 3 | } |
1907 | | |
1908 | 156 | if(exchange_state->state == libssh2_NB_state_idle) { |
1909 | | |
1910 | | /* Setup initial values */ |
1911 | 156 | exchange_state->k = _libssh2_bn_init(); |
1912 | | |
1913 | 156 | exchange_state->state = libssh2_NB_state_created; |
1914 | 156 | } |
1915 | | |
1916 | 156 | if(exchange_state->state == libssh2_NB_state_created) { |
1917 | | /* parse INIT reply data */ |
1918 | | |
1919 | | /* host key K_S */ |
1920 | 156 | unsigned char *server_public_key; |
1921 | 156 | size_t server_public_key_len; |
1922 | 156 | struct string_buf buf; |
1923 | | |
1924 | 156 | buf.data = data; |
1925 | 156 | buf.len = data_len; |
1926 | 156 | buf.dataptr = buf.data; |
1927 | 156 | buf.dataptr++; /* Advance past packet type */ |
1928 | | |
1929 | 156 | if(_libssh2_copy_string(session, &buf, &(session->server_hostkey), |
1930 | 156 | &server_public_key_len)) { |
1931 | 5 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
1932 | 5 | "Unable to allocate memory for a copy " |
1933 | 5 | "of the host ECDH key"); |
1934 | 5 | goto clean_exit; |
1935 | 5 | } |
1936 | | |
1937 | 151 | session->server_hostkey_len = (uint32_t)server_public_key_len; |
1938 | | |
1939 | | #if LIBSSH2_MD5 |
1940 | | { |
1941 | | libssh2_md5_ctx fingerprint_ctx; |
1942 | | |
1943 | | if(libssh2_md5_init(&fingerprint_ctx) && |
1944 | | libssh2_md5_update(fingerprint_ctx, session->server_hostkey, |
1945 | | session->server_hostkey_len) && |
1946 | | libssh2_md5_final(fingerprint_ctx, |
1947 | | session->server_hostkey_md5)) { |
1948 | | session->server_hostkey_md5_valid = TRUE; |
1949 | | } |
1950 | | else { |
1951 | | session->server_hostkey_md5_valid = FALSE; |
1952 | | } |
1953 | | } |
1954 | | #ifdef LIBSSH2DEBUG |
1955 | | { |
1956 | | char fingerprint[50], *fprint = fingerprint; |
1957 | | int i; |
1958 | | for(i = 0; i < 16; i++, fprint += 3) { |
1959 | | snprintf(fprint, 4, "%02x:", session->server_hostkey_md5[i]); |
1960 | | } |
1961 | | *(--fprint) = '\0'; |
1962 | | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
1963 | | "Server's MD5 Fingerprint: %s", fingerprint)); |
1964 | | } |
1965 | | #endif /* LIBSSH2DEBUG */ |
1966 | | #endif /* ! LIBSSH2_MD5 */ |
1967 | | |
1968 | 151 | { |
1969 | 151 | libssh2_sha1_ctx fingerprint_ctx; |
1970 | | |
1971 | 151 | if(libssh2_sha1_init(&fingerprint_ctx) && |
1972 | 151 | libssh2_sha1_update(fingerprint_ctx, session->server_hostkey, |
1973 | 151 | session->server_hostkey_len) && |
1974 | 151 | libssh2_sha1_final(fingerprint_ctx, |
1975 | 151 | session->server_hostkey_sha1)) { |
1976 | 151 | session->server_hostkey_sha1_valid = TRUE; |
1977 | 151 | } |
1978 | 0 | else { |
1979 | 0 | session->server_hostkey_sha1_valid = FALSE; |
1980 | 0 | } |
1981 | 151 | } |
1982 | 151 | #ifdef LIBSSH2DEBUG |
1983 | 151 | { |
1984 | 151 | char fingerprint[64], *fprint = fingerprint; |
1985 | 151 | int i; |
1986 | 3.17k | for(i = 0; i < 20; i++, fprint += 3) { |
1987 | 3.02k | snprintf(fprint, 4, "%02x:", session->server_hostkey_sha1[i]); |
1988 | 3.02k | } |
1989 | 151 | *(--fprint) = '\0'; |
1990 | 151 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
1991 | 151 | "Server's SHA1 Fingerprint: %s", fingerprint)); |
1992 | 151 | } |
1993 | 151 | #endif /* LIBSSH2DEBUG */ |
1994 | | |
1995 | | /* SHA256 */ |
1996 | 151 | { |
1997 | 151 | libssh2_sha256_ctx fingerprint_ctx; |
1998 | | |
1999 | 151 | if(libssh2_sha256_init(&fingerprint_ctx) && |
2000 | 151 | libssh2_sha256_update(fingerprint_ctx, session->server_hostkey, |
2001 | 151 | session->server_hostkey_len) && |
2002 | 151 | libssh2_sha256_final(fingerprint_ctx, |
2003 | 151 | session->server_hostkey_sha256)) { |
2004 | 151 | session->server_hostkey_sha256_valid = TRUE; |
2005 | 151 | } |
2006 | 0 | else { |
2007 | 0 | session->server_hostkey_sha256_valid = FALSE; |
2008 | 0 | } |
2009 | 151 | } |
2010 | 151 | #ifdef LIBSSH2DEBUG |
2011 | 151 | { |
2012 | 151 | char *base64Fingerprint = NULL; |
2013 | 151 | _libssh2_base64_encode(session, |
2014 | 151 | (const char *) |
2015 | 151 | session->server_hostkey_sha256, |
2016 | 151 | SHA256_DIGEST_LENGTH, &base64Fingerprint); |
2017 | 151 | if(base64Fingerprint) { |
2018 | 151 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2019 | 151 | "Server's SHA256 Fingerprint: %s", |
2020 | 151 | base64Fingerprint)); |
2021 | 151 | LIBSSH2_FREE(session, base64Fingerprint); |
2022 | 151 | } |
2023 | 151 | } |
2024 | 151 | #endif /* LIBSSH2DEBUG */ |
2025 | | |
2026 | 151 | if(session->hostkey->init(session, session->server_hostkey, |
2027 | 151 | session->server_hostkey_len, |
2028 | 151 | &session->server_hostkey_abstract)) { |
2029 | 147 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, |
2030 | 147 | "Unable to initialize hostkey importer " |
2031 | 147 | "ECDH"); |
2032 | 147 | goto clean_exit; |
2033 | 147 | } |
2034 | | |
2035 | | /* server public key Q_S */ |
2036 | 4 | if(_libssh2_get_string(&buf, &server_public_key, |
2037 | 4 | &server_public_key_len)) { |
2038 | 1 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
2039 | 1 | "Unexpected key length ECDH"); |
2040 | 1 | goto clean_exit; |
2041 | 1 | } |
2042 | | |
2043 | | /* server signature */ |
2044 | 3 | if(_libssh2_get_string(&buf, &exchange_state->h_sig, |
2045 | 3 | &(exchange_state->h_sig_len))) { |
2046 | 1 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, |
2047 | 1 | "Unexpected ECDH server sig length"); |
2048 | 1 | goto clean_exit; |
2049 | 1 | } |
2050 | | |
2051 | | /* Compute the shared secret K */ |
2052 | 2 | rc = _libssh2_ecdh_gen_k(&exchange_state->k, private_key, |
2053 | 2 | server_public_key, server_public_key_len); |
2054 | 2 | if(rc) { |
2055 | 2 | ret = _libssh2_error(session, LIBSSH2_ERROR_KEX_FAILURE, |
2056 | 2 | "Unable to create ECDH shared secret"); |
2057 | 2 | goto clean_exit; |
2058 | 2 | } |
2059 | | |
2060 | 0 | exchange_state->k_value_len = _libssh2_bn_bytes(exchange_state->k) + 5; |
2061 | 0 | if(_libssh2_bn_bits(exchange_state->k) % 8) { |
2062 | | /* don't need leading 00 */ |
2063 | 0 | exchange_state->k_value_len--; |
2064 | 0 | } |
2065 | 0 | exchange_state->k_value = |
2066 | 0 | LIBSSH2_ALLOC(session, exchange_state->k_value_len); |
2067 | 0 | if(!exchange_state->k_value) { |
2068 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
2069 | 0 | "Unable to allocate buffer for ECDH K"); |
2070 | 0 | goto clean_exit; |
2071 | 0 | } |
2072 | 0 | _libssh2_htonu32(exchange_state->k_value, |
2073 | 0 | (uint32_t)(exchange_state->k_value_len - 4)); |
2074 | 0 | if(_libssh2_bn_bits(exchange_state->k) % 8) { |
2075 | 0 | if(_libssh2_bn_to_bin(exchange_state->k, |
2076 | 0 | exchange_state->k_value + 4)) { |
2077 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY, |
2078 | 0 | "Can't write exchange_state->k"); |
2079 | 0 | goto clean_exit; |
2080 | 0 | } |
2081 | 0 | } |
2082 | 0 | else { |
2083 | 0 | exchange_state->k_value[4] = 0; |
2084 | 0 | if(_libssh2_bn_to_bin(exchange_state->k, |
2085 | 0 | exchange_state->k_value + 5)) { |
2086 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY, |
2087 | 0 | "Can't write exchange_state->e"); |
2088 | 0 | goto clean_exit; |
2089 | 0 | } |
2090 | 0 | } |
2091 | | |
2092 | | /* verify hash */ |
2093 | | |
2094 | 0 | switch(type) { |
2095 | 0 | case LIBSSH2_EC_CURVE_NISTP256: |
2096 | 0 | LIBSSH2_KEX_METHOD_EC_SHA_HASH_CREATE_VERIFY(256); |
2097 | 0 | break; |
2098 | 0 | case LIBSSH2_EC_CURVE_NISTP384: |
2099 | 0 | LIBSSH2_KEX_METHOD_EC_SHA_HASH_CREATE_VERIFY(384); |
2100 | 0 | break; |
2101 | 0 | case LIBSSH2_EC_CURVE_NISTP521: |
2102 | 0 | LIBSSH2_KEX_METHOD_EC_SHA_HASH_CREATE_VERIFY(512); |
2103 | 0 | break; |
2104 | 0 | } |
2105 | | |
2106 | 0 | if(rc) { |
2107 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_SIGN, |
2108 | 0 | "Unable to verify hostkey signature " |
2109 | 0 | "ECDH"); |
2110 | 0 | goto clean_exit; |
2111 | 0 | } |
2112 | | |
2113 | 0 | exchange_state->c = SSH_MSG_NEWKEYS; |
2114 | 0 | exchange_state->state = libssh2_NB_state_sent; |
2115 | 0 | } |
2116 | | |
2117 | 0 | if(exchange_state->state == libssh2_NB_state_sent) { |
2118 | 0 | rc = _libssh2_transport_send(session, &exchange_state->c, 1, NULL, 0); |
2119 | 0 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
2120 | 0 | return rc; |
2121 | 0 | } |
2122 | 0 | else if(rc) { |
2123 | 0 | ret = _libssh2_error(session, rc, |
2124 | 0 | "Unable to send NEWKEYS message ECDH"); |
2125 | 0 | goto clean_exit; |
2126 | 0 | } |
2127 | | |
2128 | 0 | exchange_state->state = libssh2_NB_state_sent2; |
2129 | 0 | } |
2130 | | |
2131 | 0 | if(exchange_state->state == libssh2_NB_state_sent2) { |
2132 | 0 | rc = _libssh2_packet_require(session, SSH_MSG_NEWKEYS, |
2133 | 0 | &exchange_state->tmp, |
2134 | 0 | &exchange_state->tmp_len, 0, NULL, 0, |
2135 | 0 | &exchange_state->req_state); |
2136 | 0 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
2137 | 0 | return rc; |
2138 | 0 | } |
2139 | 0 | else if(rc) { |
2140 | 0 | ret = _libssh2_error(session, rc, |
2141 | 0 | "Timed out waiting for NEWKEYS ECDH"); |
2142 | 0 | goto clean_exit; |
2143 | 0 | } |
2144 | | |
2145 | | /* The first key exchange has been performed, |
2146 | | switch to active crypt/comp/mac mode */ |
2147 | 0 | session->state |= LIBSSH2_STATE_NEWKEYS; |
2148 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2149 | 0 | "Received NEWKEYS message ECDH")); |
2150 | | |
2151 | | /* This will actually end up being just packet_type(1) |
2152 | | for this packet type anyway */ |
2153 | 0 | LIBSSH2_FREE(session, exchange_state->tmp); |
2154 | |
|
2155 | 0 | if(!session->session_id) { |
2156 | |
|
2157 | 0 | size_t digest_length = 0; |
2158 | |
|
2159 | 0 | if(type == LIBSSH2_EC_CURVE_NISTP256) |
2160 | 0 | digest_length = SHA256_DIGEST_LENGTH; |
2161 | 0 | else if(type == LIBSSH2_EC_CURVE_NISTP384) |
2162 | 0 | digest_length = SHA384_DIGEST_LENGTH; |
2163 | 0 | else if(type == LIBSSH2_EC_CURVE_NISTP521) |
2164 | 0 | digest_length = SHA512_DIGEST_LENGTH; |
2165 | 0 | else{ |
2166 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_KEX_FAILURE, |
2167 | 0 | "Unknown SHA digest for EC curve"); |
2168 | 0 | goto clean_exit; |
2169 | |
|
2170 | 0 | } |
2171 | 0 | session->session_id = LIBSSH2_ALLOC(session, digest_length); |
2172 | 0 | if(!session->session_id) { |
2173 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
2174 | 0 | "Unable to allocate buffer for " |
2175 | 0 | "SHA digest"); |
2176 | 0 | goto clean_exit; |
2177 | 0 | } |
2178 | 0 | memcpy(session->session_id, exchange_state->h_sig_comp, |
2179 | 0 | digest_length); |
2180 | 0 | session->session_id_len = (uint32_t)digest_length; |
2181 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2182 | 0 | "session_id calculated")); |
2183 | 0 | } |
2184 | | |
2185 | | /* Cleanup any existing cipher */ |
2186 | 0 | if(session->local.crypt->dtor) { |
2187 | 0 | session->local.crypt->dtor(session, |
2188 | 0 | &session->local.crypt_abstract); |
2189 | 0 | } |
2190 | | |
2191 | | /* Calculate IV/Secret/Key for each direction */ |
2192 | 0 | if(session->local.crypt->init) { |
2193 | 0 | unsigned char *iv = NULL, *secret = NULL; |
2194 | 0 | int free_iv = 0, free_secret = 0; |
2195 | |
|
2196 | 0 | LIBSSH2_KEX_METHOD_EC_SHA_VALUE_HASH(iv, |
2197 | 0 | session->local.crypt-> |
2198 | 0 | iv_len, "A"); |
2199 | 0 | if(!iv) { |
2200 | 0 | ret = -1; |
2201 | 0 | goto clean_exit; |
2202 | 0 | } |
2203 | | |
2204 | 0 | LIBSSH2_KEX_METHOD_EC_SHA_VALUE_HASH(secret, |
2205 | 0 | session->local.crypt-> |
2206 | 0 | secret_len, "C"); |
2207 | |
|
2208 | 0 | if(!secret) { |
2209 | 0 | LIBSSH2_FREE(session, iv); |
2210 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2211 | 0 | goto clean_exit; |
2212 | 0 | } |
2213 | 0 | if(session->local.crypt-> |
2214 | 0 | init(session, session->local.crypt, iv, &free_iv, secret, |
2215 | 0 | &free_secret, 1, &session->local.crypt_abstract)) { |
2216 | 0 | LIBSSH2_FREE(session, iv); |
2217 | 0 | LIBSSH2_FREE(session, secret); |
2218 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2219 | 0 | goto clean_exit; |
2220 | 0 | } |
2221 | | |
2222 | 0 | if(free_iv) { |
2223 | 0 | _libssh2_explicit_zero(iv, session->local.crypt->iv_len); |
2224 | 0 | LIBSSH2_FREE(session, iv); |
2225 | 0 | } |
2226 | |
|
2227 | 0 | if(free_secret) { |
2228 | 0 | _libssh2_explicit_zero(secret, |
2229 | 0 | session->local.crypt->secret_len); |
2230 | 0 | LIBSSH2_FREE(session, secret); |
2231 | 0 | } |
2232 | 0 | } |
2233 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2234 | 0 | "Client to Server IV and Key calculated")); |
2235 | |
|
2236 | 0 | if(session->remote.crypt->dtor) { |
2237 | | /* Cleanup any existing cipher */ |
2238 | 0 | session->remote.crypt->dtor(session, |
2239 | 0 | &session->remote.crypt_abstract); |
2240 | 0 | } |
2241 | |
|
2242 | 0 | if(session->remote.crypt->init) { |
2243 | 0 | unsigned char *iv = NULL, *secret = NULL; |
2244 | 0 | int free_iv = 0, free_secret = 0; |
2245 | |
|
2246 | 0 | LIBSSH2_KEX_METHOD_EC_SHA_VALUE_HASH(iv, |
2247 | 0 | session->remote.crypt-> |
2248 | 0 | iv_len, "B"); |
2249 | |
|
2250 | 0 | if(!iv) { |
2251 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2252 | 0 | goto clean_exit; |
2253 | 0 | } |
2254 | 0 | LIBSSH2_KEX_METHOD_EC_SHA_VALUE_HASH(secret, |
2255 | 0 | session->remote.crypt-> |
2256 | 0 | secret_len, "D"); |
2257 | |
|
2258 | 0 | if(!secret) { |
2259 | 0 | LIBSSH2_FREE(session, iv); |
2260 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2261 | 0 | goto clean_exit; |
2262 | 0 | } |
2263 | 0 | if(session->remote.crypt-> |
2264 | 0 | init(session, session->remote.crypt, iv, &free_iv, secret, |
2265 | 0 | &free_secret, 0, &session->remote.crypt_abstract)) { |
2266 | 0 | LIBSSH2_FREE(session, iv); |
2267 | 0 | LIBSSH2_FREE(session, secret); |
2268 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2269 | 0 | goto clean_exit; |
2270 | 0 | } |
2271 | | |
2272 | 0 | if(free_iv) { |
2273 | 0 | _libssh2_explicit_zero(iv, session->remote.crypt->iv_len); |
2274 | 0 | LIBSSH2_FREE(session, iv); |
2275 | 0 | } |
2276 | |
|
2277 | 0 | if(free_secret) { |
2278 | 0 | _libssh2_explicit_zero(secret, |
2279 | 0 | session->remote.crypt->secret_len); |
2280 | 0 | LIBSSH2_FREE(session, secret); |
2281 | 0 | } |
2282 | 0 | } |
2283 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2284 | 0 | "Server to Client IV and Key calculated")); |
2285 | |
|
2286 | 0 | if(session->local.mac->dtor) { |
2287 | 0 | session->local.mac->dtor(session, &session->local.mac_abstract); |
2288 | 0 | } |
2289 | |
|
2290 | 0 | if(session->local.mac->init) { |
2291 | 0 | unsigned char *key = NULL; |
2292 | 0 | int free_key = 0; |
2293 | |
|
2294 | 0 | LIBSSH2_KEX_METHOD_EC_SHA_VALUE_HASH(key, |
2295 | 0 | session->local.mac-> |
2296 | 0 | key_len, "E"); |
2297 | |
|
2298 | 0 | if(!key) { |
2299 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2300 | 0 | goto clean_exit; |
2301 | 0 | } |
2302 | 0 | session->local.mac->init(session, key, &free_key, |
2303 | 0 | &session->local.mac_abstract); |
2304 | |
|
2305 | 0 | if(free_key) { |
2306 | 0 | _libssh2_explicit_zero(key, session->local.mac->key_len); |
2307 | 0 | LIBSSH2_FREE(session, key); |
2308 | 0 | } |
2309 | 0 | } |
2310 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2311 | 0 | "Client to Server HMAC Key calculated")); |
2312 | |
|
2313 | 0 | if(session->remote.mac->dtor) { |
2314 | 0 | session->remote.mac->dtor(session, &session->remote.mac_abstract); |
2315 | 0 | } |
2316 | |
|
2317 | 0 | if(session->remote.mac->init) { |
2318 | 0 | unsigned char *key = NULL; |
2319 | 0 | int free_key = 0; |
2320 | |
|
2321 | 0 | LIBSSH2_KEX_METHOD_EC_SHA_VALUE_HASH(key, |
2322 | 0 | session->remote.mac-> |
2323 | 0 | key_len, "F"); |
2324 | |
|
2325 | 0 | if(!key) { |
2326 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2327 | 0 | goto clean_exit; |
2328 | 0 | } |
2329 | 0 | session->remote.mac->init(session, key, &free_key, |
2330 | 0 | &session->remote.mac_abstract); |
2331 | |
|
2332 | 0 | if(free_key) { |
2333 | 0 | _libssh2_explicit_zero(key, session->remote.mac->key_len); |
2334 | 0 | LIBSSH2_FREE(session, key); |
2335 | 0 | } |
2336 | 0 | } |
2337 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2338 | 0 | "Server to Client HMAC Key calculated")); |
2339 | | |
2340 | | /* Initialize compression for each direction */ |
2341 | | |
2342 | | /* Cleanup any existing compression */ |
2343 | 0 | if(session->local.comp && session->local.comp->dtor) { |
2344 | 0 | session->local.comp->dtor(session, 1, |
2345 | 0 | &session->local.comp_abstract); |
2346 | 0 | } |
2347 | |
|
2348 | 0 | if(session->local.comp && session->local.comp->init) { |
2349 | 0 | if(session->local.comp->init(session, 1, |
2350 | 0 | &session->local.comp_abstract)) { |
2351 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2352 | 0 | goto clean_exit; |
2353 | 0 | } |
2354 | 0 | } |
2355 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2356 | 0 | "Client to Server compression initialized")); |
2357 | |
|
2358 | 0 | if(session->remote.comp && session->remote.comp->dtor) { |
2359 | 0 | session->remote.comp->dtor(session, 0, |
2360 | 0 | &session->remote.comp_abstract); |
2361 | 0 | } |
2362 | |
|
2363 | 0 | if(session->remote.comp && session->remote.comp->init) { |
2364 | 0 | if(session->remote.comp->init(session, 0, |
2365 | 0 | &session->remote.comp_abstract)) { |
2366 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2367 | 0 | goto clean_exit; |
2368 | 0 | } |
2369 | 0 | } |
2370 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2371 | 0 | "Server to Client compression initialized")); |
2372 | 0 | } |
2373 | | |
2374 | 156 | clean_exit: |
2375 | 156 | ecdh_exchange_state_cleanup(session, exchange_state); |
2376 | | |
2377 | 156 | return ret; |
2378 | 0 | } |
2379 | | |
2380 | | /* kex_method_ecdh_key_exchange |
2381 | | * |
2382 | | * Elliptic Curve Diffie Hellman Key Exchange |
2383 | | * supports SHA256/384/512 hashes based on negotiated ecdh method |
2384 | | * |
2385 | | */ |
2386 | | static int |
2387 | | kex_method_ecdh_key_exchange |
2388 | | (LIBSSH2_SESSION * session, key_exchange_state_low_t * key_state) |
2389 | 233 | { |
2390 | 233 | int ret = 0; |
2391 | 233 | int rc = 0; |
2392 | 233 | unsigned char *s; |
2393 | 233 | libssh2_curve_type type; |
2394 | | |
2395 | 233 | if(key_state->state == libssh2_NB_state_idle) { |
2396 | | |
2397 | 233 | key_state->public_key_oct = NULL; |
2398 | 233 | key_state->state = libssh2_NB_state_created; |
2399 | 233 | } |
2400 | | |
2401 | 233 | if(key_state->state == libssh2_NB_state_created) { |
2402 | 233 | rc = kex_session_ecdh_curve_type(session->kex->name, &type); |
2403 | | |
2404 | 233 | if(rc) { |
2405 | 0 | ret = _libssh2_error(session, -1, |
2406 | 0 | "Unknown KEX nistp curve type"); |
2407 | 0 | goto ecdh_clean_exit; |
2408 | 0 | } |
2409 | | |
2410 | 233 | rc = _libssh2_ecdsa_create_key(session, &key_state->private_key, |
2411 | 233 | &key_state->public_key_oct, |
2412 | 233 | &key_state->public_key_oct_len, type); |
2413 | | |
2414 | 233 | if(rc) { |
2415 | 0 | ret = _libssh2_error(session, rc, |
2416 | 0 | "Unable to create private key"); |
2417 | 0 | goto ecdh_clean_exit; |
2418 | 0 | } |
2419 | | |
2420 | 233 | key_state->request[0] = SSH2_MSG_KEX_ECDH_INIT; |
2421 | 233 | s = key_state->request + 1; |
2422 | 233 | _libssh2_store_str(&s, (const char *)key_state->public_key_oct, |
2423 | 233 | key_state->public_key_oct_len); |
2424 | 233 | key_state->request_len = key_state->public_key_oct_len + 5; |
2425 | | |
2426 | 233 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2427 | 233 | "Initiating ECDH SHA2 NISTP256")); |
2428 | | |
2429 | 233 | key_state->state = libssh2_NB_state_sent; |
2430 | 233 | } |
2431 | | |
2432 | 233 | if(key_state->state == libssh2_NB_state_sent) { |
2433 | 233 | rc = _libssh2_transport_send(session, key_state->request, |
2434 | 233 | key_state->request_len, NULL, 0); |
2435 | 233 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
2436 | 0 | return rc; |
2437 | 0 | } |
2438 | 233 | else if(rc) { |
2439 | 0 | ret = _libssh2_error(session, rc, |
2440 | 0 | "Unable to send ECDH_INIT"); |
2441 | 0 | goto ecdh_clean_exit; |
2442 | 0 | } |
2443 | | |
2444 | 233 | key_state->state = libssh2_NB_state_sent1; |
2445 | 233 | } |
2446 | | |
2447 | 233 | if(key_state->state == libssh2_NB_state_sent1) { |
2448 | 233 | rc = _libssh2_packet_require(session, SSH2_MSG_KEX_ECDH_REPLY, |
2449 | 233 | &key_state->data, &key_state->data_len, |
2450 | 233 | 0, NULL, 0, &key_state->req_state); |
2451 | 233 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
2452 | 0 | return rc; |
2453 | 0 | } |
2454 | 233 | else if(rc) { |
2455 | 74 | ret = _libssh2_error(session, rc, |
2456 | 74 | "Timeout waiting for ECDH_REPLY reply"); |
2457 | 74 | goto ecdh_clean_exit; |
2458 | 74 | } |
2459 | | |
2460 | 159 | key_state->state = libssh2_NB_state_sent2; |
2461 | 159 | } |
2462 | | |
2463 | 159 | if(key_state->state == libssh2_NB_state_sent2) { |
2464 | | |
2465 | 159 | rc = kex_session_ecdh_curve_type(session->kex->name, &type); |
2466 | | |
2467 | 159 | if(rc) { |
2468 | 0 | ret = _libssh2_error(session, -1, |
2469 | 0 | "Unknown KEX nistp curve type"); |
2470 | 0 | goto ecdh_clean_exit; |
2471 | 0 | } |
2472 | | |
2473 | 159 | ret = ecdh_sha2_nistp(session, type, key_state->data, |
2474 | 159 | key_state->data_len, |
2475 | 159 | (unsigned char *)key_state->public_key_oct, |
2476 | 159 | key_state->public_key_oct_len, |
2477 | 159 | key_state->private_key, |
2478 | 159 | &key_state->exchange_state); |
2479 | | |
2480 | 159 | if(ret == LIBSSH2_ERROR_EAGAIN) { |
2481 | 0 | return ret; |
2482 | 0 | } |
2483 | 159 | } |
2484 | | |
2485 | 233 | ecdh_clean_exit: |
2486 | | |
2487 | 233 | kex_method_ecdh_cleanup(session, key_state); |
2488 | | |
2489 | 233 | return ret; |
2490 | 159 | } |
2491 | | |
2492 | | #endif /* LIBSSH2_ECDSA */ |
2493 | | |
2494 | | |
2495 | | #if LIBSSH2_ED25519 |
2496 | | |
2497 | | static void |
2498 | | curve25519_exchange_state_cleanup(LIBSSH2_SESSION * session, |
2499 | | kmdhgGPshakex_state_t *exchange_state) |
2500 | 48 | { |
2501 | 48 | _libssh2_bn_free(exchange_state->k); |
2502 | 48 | exchange_state->k = NULL; |
2503 | | |
2504 | 48 | if(exchange_state->k_value) { |
2505 | 6 | LIBSSH2_FREE(session, exchange_state->k_value); |
2506 | 6 | exchange_state->k_value = NULL; |
2507 | 6 | } |
2508 | | |
2509 | 48 | exchange_state->state = libssh2_NB_state_idle; |
2510 | 48 | } |
2511 | | |
2512 | | static void |
2513 | | kex_method_curve25519_cleanup |
2514 | | (LIBSSH2_SESSION * session, key_exchange_state_low_t * key_state) |
2515 | 328 | { |
2516 | 328 | if(key_state->curve25519_public_key) { |
2517 | 136 | _libssh2_explicit_zero(key_state->curve25519_public_key, |
2518 | 136 | LIBSSH2_ED25519_KEY_LEN); |
2519 | 136 | LIBSSH2_FREE(session, key_state->curve25519_public_key); |
2520 | 136 | key_state->curve25519_public_key = NULL; |
2521 | 136 | } |
2522 | | |
2523 | 328 | if(key_state->curve25519_private_key) { |
2524 | 136 | _libssh2_explicit_zero(key_state->curve25519_private_key, |
2525 | 136 | LIBSSH2_ED25519_KEY_LEN); |
2526 | 136 | LIBSSH2_FREE(session, key_state->curve25519_private_key); |
2527 | 136 | key_state->curve25519_private_key = NULL; |
2528 | 136 | } |
2529 | | |
2530 | 328 | if(key_state->data) { |
2531 | 50 | LIBSSH2_FREE(session, key_state->data); |
2532 | 50 | key_state->data = NULL; |
2533 | 50 | } |
2534 | | |
2535 | 328 | key_state->state = libssh2_NB_state_idle; |
2536 | | |
2537 | 328 | if(key_state->exchange_state.state != libssh2_NB_state_idle) { |
2538 | 0 | curve25519_exchange_state_cleanup(session, &key_state->exchange_state); |
2539 | 0 | } |
2540 | 328 | } |
2541 | | |
2542 | | /* curve25519_sha256 |
2543 | | * Elliptic Curve Key Exchange |
2544 | | */ |
2545 | | static int |
2546 | | curve25519_sha256(LIBSSH2_SESSION *session, unsigned char *data, |
2547 | | size_t data_len, |
2548 | | unsigned char public_key[LIBSSH2_ED25519_KEY_LEN], |
2549 | | unsigned char private_key[LIBSSH2_ED25519_KEY_LEN], |
2550 | | kmdhgGPshakex_state_t *exchange_state) |
2551 | 50 | { |
2552 | 50 | int ret = 0; |
2553 | 50 | int rc; |
2554 | 50 | int public_key_len = LIBSSH2_ED25519_KEY_LEN; |
2555 | | |
2556 | 50 | if(data_len < 5) { |
2557 | 2 | return _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, |
2558 | 2 | "Data is too short"); |
2559 | 2 | } |
2560 | | |
2561 | 48 | if(exchange_state->state == libssh2_NB_state_idle) { |
2562 | | |
2563 | | /* Setup initial values */ |
2564 | 48 | exchange_state->k = _libssh2_bn_init(); |
2565 | | |
2566 | 48 | exchange_state->state = libssh2_NB_state_created; |
2567 | 48 | } |
2568 | | |
2569 | 48 | if(exchange_state->state == libssh2_NB_state_created) { |
2570 | | /* parse INIT reply data */ |
2571 | 48 | unsigned char *server_public_key, *server_host_key; |
2572 | 48 | size_t server_public_key_len, hostkey_len; |
2573 | 48 | struct string_buf buf; |
2574 | | |
2575 | 48 | if(data_len < 5) { |
2576 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
2577 | 0 | "Unexpected curve25519 key length 1"); |
2578 | 0 | goto clean_exit; |
2579 | 0 | } |
2580 | | |
2581 | 48 | buf.data = data; |
2582 | 48 | buf.len = data_len; |
2583 | 48 | buf.dataptr = buf.data; |
2584 | 48 | buf.dataptr++; /* advance past packet type */ |
2585 | | |
2586 | 48 | if(_libssh2_get_string(&buf, &server_host_key, &hostkey_len)) { |
2587 | 2 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
2588 | 2 | "Unexpected curve25519 key length 2"); |
2589 | 2 | goto clean_exit; |
2590 | 2 | } |
2591 | | |
2592 | 46 | session->server_hostkey_len = (uint32_t)hostkey_len; |
2593 | 46 | session->server_hostkey = LIBSSH2_ALLOC(session, |
2594 | 46 | session->server_hostkey_len); |
2595 | 46 | if(!session->server_hostkey) { |
2596 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
2597 | 0 | "Unable to allocate memory for a copy " |
2598 | 0 | "of the host curve25519 key"); |
2599 | 0 | goto clean_exit; |
2600 | 0 | } |
2601 | | |
2602 | 46 | memcpy(session->server_hostkey, server_host_key, |
2603 | 46 | session->server_hostkey_len); |
2604 | | |
2605 | | #if LIBSSH2_MD5 |
2606 | | { |
2607 | | libssh2_md5_ctx fingerprint_ctx; |
2608 | | |
2609 | | if(libssh2_md5_init(&fingerprint_ctx) && |
2610 | | libssh2_md5_update(fingerprint_ctx, session->server_hostkey, |
2611 | | session->server_hostkey_len) && |
2612 | | libssh2_md5_final(fingerprint_ctx, |
2613 | | session->server_hostkey_md5)) { |
2614 | | session->server_hostkey_md5_valid = TRUE; |
2615 | | } |
2616 | | else { |
2617 | | session->server_hostkey_md5_valid = FALSE; |
2618 | | } |
2619 | | } |
2620 | | #ifdef LIBSSH2DEBUG |
2621 | | { |
2622 | | char fingerprint[50], *fprint = fingerprint; |
2623 | | int i; |
2624 | | for(i = 0; i < 16; i++, fprint += 3) { |
2625 | | snprintf(fprint, 4, "%02x:", session->server_hostkey_md5[i]); |
2626 | | } |
2627 | | *(--fprint) = '\0'; |
2628 | | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2629 | | "Server's MD5 Fingerprint: %s", fingerprint)); |
2630 | | } |
2631 | | #endif /* LIBSSH2DEBUG */ |
2632 | | #endif /* ! LIBSSH2_MD5 */ |
2633 | | |
2634 | 46 | { |
2635 | 46 | libssh2_sha1_ctx fingerprint_ctx; |
2636 | | |
2637 | 46 | if(libssh2_sha1_init(&fingerprint_ctx) && |
2638 | 46 | libssh2_sha1_update(fingerprint_ctx, session->server_hostkey, |
2639 | 46 | session->server_hostkey_len) && |
2640 | 46 | libssh2_sha1_final(fingerprint_ctx, |
2641 | 46 | session->server_hostkey_sha1)) { |
2642 | 46 | session->server_hostkey_sha1_valid = TRUE; |
2643 | 46 | } |
2644 | 0 | else { |
2645 | 0 | session->server_hostkey_sha1_valid = FALSE; |
2646 | 0 | } |
2647 | 46 | } |
2648 | 46 | #ifdef LIBSSH2DEBUG |
2649 | 46 | { |
2650 | 46 | char fingerprint[64], *fprint = fingerprint; |
2651 | 46 | int i; |
2652 | 966 | for(i = 0; i < 20; i++, fprint += 3) { |
2653 | 920 | snprintf(fprint, 4, "%02x:", session->server_hostkey_sha1[i]); |
2654 | 920 | } |
2655 | 46 | *(--fprint) = '\0'; |
2656 | 46 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2657 | 46 | "Server's SHA1 Fingerprint: %s", fingerprint)); |
2658 | 46 | } |
2659 | 46 | #endif /* LIBSSH2DEBUG */ |
2660 | | |
2661 | | /* SHA256 */ |
2662 | 46 | { |
2663 | 46 | libssh2_sha256_ctx fingerprint_ctx; |
2664 | | |
2665 | 46 | if(libssh2_sha256_init(&fingerprint_ctx) && |
2666 | 46 | libssh2_sha256_update(fingerprint_ctx, session->server_hostkey, |
2667 | 46 | session->server_hostkey_len) && |
2668 | 46 | libssh2_sha256_final(fingerprint_ctx, |
2669 | 46 | session->server_hostkey_sha256)) { |
2670 | 46 | session->server_hostkey_sha256_valid = TRUE; |
2671 | 46 | } |
2672 | 0 | else { |
2673 | 0 | session->server_hostkey_sha256_valid = FALSE; |
2674 | 0 | } |
2675 | 46 | } |
2676 | 46 | #ifdef LIBSSH2DEBUG |
2677 | 46 | { |
2678 | 46 | char *base64Fingerprint = NULL; |
2679 | 46 | _libssh2_base64_encode(session, |
2680 | 46 | (const char *) |
2681 | 46 | session->server_hostkey_sha256, |
2682 | 46 | SHA256_DIGEST_LENGTH, &base64Fingerprint); |
2683 | 46 | if(base64Fingerprint) { |
2684 | 46 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2685 | 46 | "Server's SHA256 Fingerprint: %s", |
2686 | 46 | base64Fingerprint)); |
2687 | 46 | LIBSSH2_FREE(session, base64Fingerprint); |
2688 | 46 | } |
2689 | 46 | } |
2690 | 46 | #endif /* LIBSSH2DEBUG */ |
2691 | | |
2692 | 46 | if(session->hostkey->init(session, session->server_hostkey, |
2693 | 46 | session->server_hostkey_len, |
2694 | 46 | &session->server_hostkey_abstract)) { |
2695 | 36 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, |
2696 | 36 | "Unable to initialize hostkey importer " |
2697 | 36 | "curve25519"); |
2698 | 36 | goto clean_exit; |
2699 | 36 | } |
2700 | | |
2701 | | /* server public key Q_S */ |
2702 | 10 | if(_libssh2_get_string(&buf, &server_public_key, |
2703 | 10 | &server_public_key_len)) { |
2704 | 1 | ret = _libssh2_error(session, LIBSSH2_ERROR_PROTO, |
2705 | 1 | "Unexpected curve25519 key length"); |
2706 | 1 | goto clean_exit; |
2707 | 1 | } |
2708 | | |
2709 | 9 | if(server_public_key_len != LIBSSH2_ED25519_KEY_LEN) { |
2710 | 1 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, |
2711 | 1 | "Unexpected curve25519 server " |
2712 | 1 | "public key length"); |
2713 | 1 | goto clean_exit; |
2714 | 1 | } |
2715 | | |
2716 | | /* server signature */ |
2717 | 8 | if(_libssh2_get_string(&buf, &exchange_state->h_sig, |
2718 | 8 | &(exchange_state->h_sig_len))) { |
2719 | 1 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, |
2720 | 1 | "Unexpected curve25519 server sig length"); |
2721 | 1 | goto clean_exit; |
2722 | 1 | } |
2723 | | |
2724 | | /* Compute the shared secret K */ |
2725 | 7 | rc = _libssh2_curve25519_gen_k(&exchange_state->k, private_key, |
2726 | 7 | server_public_key); |
2727 | 7 | if(rc) { |
2728 | 1 | ret = _libssh2_error(session, LIBSSH2_ERROR_KEX_FAILURE, |
2729 | 1 | "Unable to create curve25519 shared secret"); |
2730 | 1 | goto clean_exit; |
2731 | 1 | } |
2732 | | |
2733 | 6 | exchange_state->k_value_len = _libssh2_bn_bytes(exchange_state->k) + 5; |
2734 | 6 | if(_libssh2_bn_bits(exchange_state->k) % 8) { |
2735 | | /* don't need leading 00 */ |
2736 | 1 | exchange_state->k_value_len--; |
2737 | 1 | } |
2738 | 6 | exchange_state->k_value = |
2739 | 6 | LIBSSH2_ALLOC(session, exchange_state->k_value_len); |
2740 | 6 | if(!exchange_state->k_value) { |
2741 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
2742 | 0 | "Unable to allocate buffer for K"); |
2743 | 0 | goto clean_exit; |
2744 | 0 | } |
2745 | 6 | _libssh2_htonu32(exchange_state->k_value, |
2746 | 6 | (uint32_t)(exchange_state->k_value_len - 4)); |
2747 | 6 | if(_libssh2_bn_bits(exchange_state->k) % 8) { |
2748 | 1 | if(_libssh2_bn_to_bin(exchange_state->k, |
2749 | 1 | exchange_state->k_value + 4)) { |
2750 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY, |
2751 | 0 | "Can't write exchange_state->e"); |
2752 | 0 | goto clean_exit; |
2753 | 0 | } |
2754 | 1 | } |
2755 | 5 | else { |
2756 | 5 | exchange_state->k_value[4] = 0; |
2757 | 5 | if(_libssh2_bn_to_bin(exchange_state->k, |
2758 | 5 | exchange_state->k_value + 5)) { |
2759 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY, |
2760 | 0 | "Can't write exchange_state->e"); |
2761 | 0 | goto clean_exit; |
2762 | 0 | } |
2763 | 5 | } |
2764 | | |
2765 | | /*/ verify hash */ |
2766 | 6 | LIBSSH2_KEX_METHOD_EC_SHA_HASH_CREATE_VERIFY(256); |
2767 | | |
2768 | 6 | if(rc) { |
2769 | 6 | ret = _libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_SIGN, |
2770 | 6 | "Unable to verify hostkey signature " |
2771 | 6 | "curve25519"); |
2772 | 6 | goto clean_exit; |
2773 | 6 | } |
2774 | | |
2775 | 0 | exchange_state->c = SSH_MSG_NEWKEYS; |
2776 | 0 | exchange_state->state = libssh2_NB_state_sent; |
2777 | 0 | } |
2778 | | |
2779 | 0 | if(exchange_state->state == libssh2_NB_state_sent) { |
2780 | 0 | rc = _libssh2_transport_send(session, &exchange_state->c, 1, NULL, 0); |
2781 | 0 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
2782 | 0 | return rc; |
2783 | 0 | } |
2784 | 0 | else if(rc) { |
2785 | 0 | ret = _libssh2_error(session, rc, |
2786 | 0 | "Unable to send NEWKEYS message curve25519"); |
2787 | 0 | goto clean_exit; |
2788 | 0 | } |
2789 | | |
2790 | 0 | exchange_state->state = libssh2_NB_state_sent2; |
2791 | 0 | } |
2792 | | |
2793 | 0 | if(exchange_state->state == libssh2_NB_state_sent2) { |
2794 | 0 | rc = _libssh2_packet_require(session, SSH_MSG_NEWKEYS, |
2795 | 0 | &exchange_state->tmp, |
2796 | 0 | &exchange_state->tmp_len, 0, NULL, 0, |
2797 | 0 | &exchange_state->req_state); |
2798 | 0 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
2799 | 0 | return rc; |
2800 | 0 | } |
2801 | 0 | else if(rc) { |
2802 | 0 | ret = _libssh2_error(session, rc, |
2803 | 0 | "Timed out waiting for NEWKEYS curve25519"); |
2804 | 0 | goto clean_exit; |
2805 | 0 | } |
2806 | | |
2807 | | /* The first key exchange has been performed, |
2808 | | switch to active crypt/comp/mac mode */ |
2809 | 0 | session->state |= LIBSSH2_STATE_NEWKEYS; |
2810 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2811 | 0 | "Received NEWKEYS message curve25519")); |
2812 | | |
2813 | | /* This will actually end up being just packet_type(1) |
2814 | | for this packet type anyway */ |
2815 | 0 | LIBSSH2_FREE(session, exchange_state->tmp); |
2816 | |
|
2817 | 0 | if(!session->session_id) { |
2818 | |
|
2819 | 0 | size_t digest_length = SHA256_DIGEST_LENGTH; |
2820 | 0 | session->session_id = LIBSSH2_ALLOC(session, digest_length); |
2821 | 0 | if(!session->session_id) { |
2822 | 0 | ret = _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
2823 | 0 | "Unable to allocate buffer for " |
2824 | 0 | "SHA digest"); |
2825 | 0 | goto clean_exit; |
2826 | 0 | } |
2827 | 0 | memcpy(session->session_id, exchange_state->h_sig_comp, |
2828 | 0 | digest_length); |
2829 | 0 | session->session_id_len = (uint32_t)digest_length; |
2830 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2831 | 0 | "session_id calculated")); |
2832 | 0 | } |
2833 | | |
2834 | | /* Cleanup any existing cipher */ |
2835 | 0 | if(session->local.crypt->dtor) { |
2836 | 0 | session->local.crypt->dtor(session, |
2837 | 0 | &session->local.crypt_abstract); |
2838 | 0 | } |
2839 | | |
2840 | | /* Calculate IV/Secret/Key for each direction */ |
2841 | 0 | if(session->local.crypt->init) { |
2842 | 0 | unsigned char *iv = NULL, *secret = NULL; |
2843 | 0 | int free_iv = 0, free_secret = 0; |
2844 | |
|
2845 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(256, iv, |
2846 | 0 | session->local.crypt-> |
2847 | 0 | iv_len, "A"); |
2848 | 0 | if(!iv) { |
2849 | 0 | ret = -1; |
2850 | 0 | goto clean_exit; |
2851 | 0 | } |
2852 | | |
2853 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(256, secret, |
2854 | 0 | session->local.crypt-> |
2855 | 0 | secret_len, "C"); |
2856 | |
|
2857 | 0 | if(!secret) { |
2858 | 0 | LIBSSH2_FREE(session, iv); |
2859 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2860 | 0 | goto clean_exit; |
2861 | 0 | } |
2862 | 0 | if(session->local.crypt-> |
2863 | 0 | init(session, session->local.crypt, iv, &free_iv, secret, |
2864 | 0 | &free_secret, 1, &session->local.crypt_abstract)) { |
2865 | 0 | LIBSSH2_FREE(session, iv); |
2866 | 0 | LIBSSH2_FREE(session, secret); |
2867 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2868 | 0 | goto clean_exit; |
2869 | 0 | } |
2870 | | |
2871 | 0 | if(free_iv) { |
2872 | 0 | _libssh2_explicit_zero(iv, session->local.crypt->iv_len); |
2873 | 0 | LIBSSH2_FREE(session, iv); |
2874 | 0 | } |
2875 | |
|
2876 | 0 | if(free_secret) { |
2877 | 0 | _libssh2_explicit_zero(secret, |
2878 | 0 | session->local.crypt->secret_len); |
2879 | 0 | LIBSSH2_FREE(session, secret); |
2880 | 0 | } |
2881 | 0 | } |
2882 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2883 | 0 | "Client to Server IV and Key calculated")); |
2884 | |
|
2885 | 0 | if(session->remote.crypt->dtor) { |
2886 | | /* Cleanup any existing cipher */ |
2887 | 0 | session->remote.crypt->dtor(session, |
2888 | 0 | &session->remote.crypt_abstract); |
2889 | 0 | } |
2890 | |
|
2891 | 0 | if(session->remote.crypt->init) { |
2892 | 0 | unsigned char *iv = NULL, *secret = NULL; |
2893 | 0 | int free_iv = 0, free_secret = 0; |
2894 | |
|
2895 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(256, iv, |
2896 | 0 | session->remote.crypt-> |
2897 | 0 | iv_len, "B"); |
2898 | |
|
2899 | 0 | if(!iv) { |
2900 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2901 | 0 | goto clean_exit; |
2902 | 0 | } |
2903 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(256, secret, |
2904 | 0 | session->remote.crypt-> |
2905 | 0 | secret_len, "D"); |
2906 | |
|
2907 | 0 | if(!secret) { |
2908 | 0 | LIBSSH2_FREE(session, iv); |
2909 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2910 | 0 | goto clean_exit; |
2911 | 0 | } |
2912 | 0 | if(session->remote.crypt-> |
2913 | 0 | init(session, session->remote.crypt, iv, &free_iv, secret, |
2914 | 0 | &free_secret, 0, &session->remote.crypt_abstract)) { |
2915 | 0 | LIBSSH2_FREE(session, iv); |
2916 | 0 | LIBSSH2_FREE(session, secret); |
2917 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2918 | 0 | goto clean_exit; |
2919 | 0 | } |
2920 | | |
2921 | 0 | if(free_iv) { |
2922 | 0 | _libssh2_explicit_zero(iv, session->remote.crypt->iv_len); |
2923 | 0 | LIBSSH2_FREE(session, iv); |
2924 | 0 | } |
2925 | |
|
2926 | 0 | if(free_secret) { |
2927 | 0 | _libssh2_explicit_zero(secret, |
2928 | 0 | session->remote.crypt->secret_len); |
2929 | 0 | LIBSSH2_FREE(session, secret); |
2930 | 0 | } |
2931 | 0 | } |
2932 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2933 | 0 | "Server to Client IV and Key calculated")); |
2934 | |
|
2935 | 0 | if(session->local.mac->dtor) { |
2936 | 0 | session->local.mac->dtor(session, &session->local.mac_abstract); |
2937 | 0 | } |
2938 | |
|
2939 | 0 | if(session->local.mac->init) { |
2940 | 0 | unsigned char *key = NULL; |
2941 | 0 | int free_key = 0; |
2942 | |
|
2943 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(256, key, |
2944 | 0 | session->local.mac-> |
2945 | 0 | key_len, "E"); |
2946 | |
|
2947 | 0 | if(!key) { |
2948 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2949 | 0 | goto clean_exit; |
2950 | 0 | } |
2951 | 0 | session->local.mac->init(session, key, &free_key, |
2952 | 0 | &session->local.mac_abstract); |
2953 | |
|
2954 | 0 | if(free_key) { |
2955 | 0 | _libssh2_explicit_zero(key, session->local.mac->key_len); |
2956 | 0 | LIBSSH2_FREE(session, key); |
2957 | 0 | } |
2958 | 0 | } |
2959 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2960 | 0 | "Client to Server HMAC Key calculated")); |
2961 | |
|
2962 | 0 | if(session->remote.mac->dtor) { |
2963 | 0 | session->remote.mac->dtor(session, &session->remote.mac_abstract); |
2964 | 0 | } |
2965 | |
|
2966 | 0 | if(session->remote.mac->init) { |
2967 | 0 | unsigned char *key = NULL; |
2968 | 0 | int free_key = 0; |
2969 | |
|
2970 | 0 | LIBSSH2_KEX_METHOD_SHA_VALUE_HASH(256, key, |
2971 | 0 | session->remote.mac-> |
2972 | 0 | key_len, "F"); |
2973 | |
|
2974 | 0 | if(!key) { |
2975 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
2976 | 0 | goto clean_exit; |
2977 | 0 | } |
2978 | 0 | session->remote.mac->init(session, key, &free_key, |
2979 | 0 | &session->remote.mac_abstract); |
2980 | |
|
2981 | 0 | if(free_key) { |
2982 | 0 | _libssh2_explicit_zero(key, session->remote.mac->key_len); |
2983 | 0 | LIBSSH2_FREE(session, key); |
2984 | 0 | } |
2985 | 0 | } |
2986 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
2987 | 0 | "Server to Client HMAC Key calculated")); |
2988 | | |
2989 | | /* Initialize compression for each direction */ |
2990 | | |
2991 | | /* Cleanup any existing compression */ |
2992 | 0 | if(session->local.comp && session->local.comp->dtor) { |
2993 | 0 | session->local.comp->dtor(session, 1, |
2994 | 0 | &session->local.comp_abstract); |
2995 | 0 | } |
2996 | |
|
2997 | 0 | if(session->local.comp && session->local.comp->init) { |
2998 | 0 | if(session->local.comp->init(session, 1, |
2999 | 0 | &session->local.comp_abstract)) { |
3000 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
3001 | 0 | goto clean_exit; |
3002 | 0 | } |
3003 | 0 | } |
3004 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3005 | 0 | "Client to Server compression initialized")); |
3006 | |
|
3007 | 0 | if(session->remote.comp && session->remote.comp->dtor) { |
3008 | 0 | session->remote.comp->dtor(session, 0, |
3009 | 0 | &session->remote.comp_abstract); |
3010 | 0 | } |
3011 | |
|
3012 | 0 | if(session->remote.comp && session->remote.comp->init) { |
3013 | 0 | if(session->remote.comp->init(session, 0, |
3014 | 0 | &session->remote.comp_abstract)) { |
3015 | 0 | ret = LIBSSH2_ERROR_KEX_FAILURE; |
3016 | 0 | goto clean_exit; |
3017 | 0 | } |
3018 | 0 | } |
3019 | 0 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3020 | 0 | "Server to Client compression initialized")); |
3021 | 0 | } |
3022 | | |
3023 | 48 | clean_exit: |
3024 | 48 | curve25519_exchange_state_cleanup(session, exchange_state); |
3025 | | |
3026 | 48 | return ret; |
3027 | 0 | } |
3028 | | |
3029 | | /* kex_method_curve25519_key_exchange |
3030 | | * |
3031 | | * Elliptic Curve X25519 Key Exchange with SHA256 hash |
3032 | | * |
3033 | | */ |
3034 | | static int |
3035 | | kex_method_curve25519_key_exchange |
3036 | | (LIBSSH2_SESSION * session, key_exchange_state_low_t * key_state) |
3037 | 136 | { |
3038 | 136 | int ret = 0; |
3039 | 136 | int rc = 0; |
3040 | | |
3041 | 136 | if(key_state->state == libssh2_NB_state_idle) { |
3042 | | |
3043 | 136 | key_state->public_key_oct = NULL; |
3044 | 136 | key_state->state = libssh2_NB_state_created; |
3045 | 136 | } |
3046 | | |
3047 | 136 | if(key_state->state == libssh2_NB_state_created) { |
3048 | 136 | unsigned char *s = NULL; |
3049 | | |
3050 | 136 | rc = strcmp(session->kex->name, "curve25519-sha256@libssh.org"); |
3051 | 136 | if(rc) |
3052 | 134 | rc = strcmp(session->kex->name, "curve25519-sha256"); |
3053 | | |
3054 | 136 | if(rc) { |
3055 | 0 | ret = _libssh2_error(session, -1, |
3056 | 0 | "Unknown KEX curve25519 curve type"); |
3057 | 0 | goto clean_exit; |
3058 | 0 | } |
3059 | | |
3060 | 136 | rc = _libssh2_curve25519_new(session, |
3061 | 136 | &key_state->curve25519_public_key, |
3062 | 136 | &key_state->curve25519_private_key); |
3063 | | |
3064 | 136 | if(rc) { |
3065 | 0 | ret = _libssh2_error(session, rc, |
3066 | 0 | "Unable to create private key"); |
3067 | 0 | goto clean_exit; |
3068 | 0 | } |
3069 | | |
3070 | 136 | key_state->request[0] = SSH2_MSG_KEX_ECDH_INIT; |
3071 | 136 | s = key_state->request + 1; |
3072 | 136 | _libssh2_store_str(&s, (const char *)key_state->curve25519_public_key, |
3073 | 136 | LIBSSH2_ED25519_KEY_LEN); |
3074 | 136 | key_state->request_len = LIBSSH2_ED25519_KEY_LEN + 5; |
3075 | | |
3076 | 136 | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3077 | 136 | "Initiating curve25519 SHA2")); |
3078 | | |
3079 | 136 | key_state->state = libssh2_NB_state_sent; |
3080 | 136 | } |
3081 | | |
3082 | 136 | if(key_state->state == libssh2_NB_state_sent) { |
3083 | 136 | rc = _libssh2_transport_send(session, key_state->request, |
3084 | 136 | key_state->request_len, NULL, 0); |
3085 | 136 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
3086 | 0 | return rc; |
3087 | 0 | } |
3088 | 136 | else if(rc) { |
3089 | 0 | ret = _libssh2_error(session, rc, |
3090 | 0 | "Unable to send ECDH_INIT"); |
3091 | 0 | goto clean_exit; |
3092 | 0 | } |
3093 | | |
3094 | 136 | key_state->state = libssh2_NB_state_sent1; |
3095 | 136 | } |
3096 | | |
3097 | 136 | if(key_state->state == libssh2_NB_state_sent1) { |
3098 | 136 | rc = _libssh2_packet_require(session, SSH2_MSG_KEX_ECDH_REPLY, |
3099 | 136 | &key_state->data, &key_state->data_len, |
3100 | 136 | 0, NULL, 0, &key_state->req_state); |
3101 | 136 | if(rc == LIBSSH2_ERROR_EAGAIN) { |
3102 | 0 | return rc; |
3103 | 0 | } |
3104 | 136 | else if(rc) { |
3105 | 86 | ret = _libssh2_error(session, rc, |
3106 | 86 | "Timeout waiting for ECDH_REPLY reply"); |
3107 | 86 | goto clean_exit; |
3108 | 86 | } |
3109 | | |
3110 | 50 | key_state->state = libssh2_NB_state_sent2; |
3111 | 50 | } |
3112 | | |
3113 | 50 | if(key_state->state == libssh2_NB_state_sent2) { |
3114 | | |
3115 | 50 | ret = curve25519_sha256(session, key_state->data, key_state->data_len, |
3116 | 50 | key_state->curve25519_public_key, |
3117 | 50 | key_state->curve25519_private_key, |
3118 | 50 | &key_state->exchange_state); |
3119 | | |
3120 | 50 | if(ret == LIBSSH2_ERROR_EAGAIN) { |
3121 | 0 | return ret; |
3122 | 0 | } |
3123 | 50 | } |
3124 | | |
3125 | 136 | clean_exit: |
3126 | | |
3127 | 136 | kex_method_curve25519_cleanup(session, key_state); |
3128 | | |
3129 | 136 | return ret; |
3130 | 50 | } |
3131 | | |
3132 | | |
3133 | | #endif /* LIBSSH2_ED25519 */ |
3134 | | |
3135 | | |
3136 | 2.20k | #define LIBSSH2_KEX_METHOD_FLAG_REQ_ENC_HOSTKEY 0x0001 |
3137 | 2.20k | #define LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY 0x0002 |
3138 | | |
3139 | | static const LIBSSH2_KEX_METHOD kex_method_diffie_helman_group1_sha1 = { |
3140 | | "diffie-hellman-group1-sha1", |
3141 | | kex_method_diffie_hellman_group1_sha1_key_exchange, |
3142 | | kex_diffie_hellman_cleanup, |
3143 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3144 | | }; |
3145 | | |
3146 | | static const LIBSSH2_KEX_METHOD kex_method_diffie_helman_group14_sha1 = { |
3147 | | "diffie-hellman-group14-sha1", |
3148 | | kex_method_diffie_hellman_group14_sha1_key_exchange, |
3149 | | kex_diffie_hellman_cleanup, |
3150 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3151 | | }; |
3152 | | |
3153 | | static const LIBSSH2_KEX_METHOD kex_method_diffie_helman_group14_sha256 = { |
3154 | | "diffie-hellman-group14-sha256", |
3155 | | kex_method_diffie_hellman_group14_sha256_key_exchange, |
3156 | | kex_diffie_hellman_cleanup, |
3157 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3158 | | }; |
3159 | | |
3160 | | static const LIBSSH2_KEX_METHOD kex_method_diffie_helman_group16_sha512 = { |
3161 | | "diffie-hellman-group16-sha512", |
3162 | | kex_method_diffie_hellman_group16_sha512_key_exchange, |
3163 | | kex_diffie_hellman_cleanup, |
3164 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3165 | | }; |
3166 | | |
3167 | | static const LIBSSH2_KEX_METHOD kex_method_diffie_helman_group18_sha512 = { |
3168 | | "diffie-hellman-group18-sha512", |
3169 | | kex_method_diffie_hellman_group18_sha512_key_exchange, |
3170 | | kex_diffie_hellman_cleanup, |
3171 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3172 | | }; |
3173 | | |
3174 | | static const LIBSSH2_KEX_METHOD |
3175 | | kex_method_diffie_helman_group_exchange_sha1 = { |
3176 | | "diffie-hellman-group-exchange-sha1", |
3177 | | kex_method_diffie_hellman_group_exchange_sha1_key_exchange, |
3178 | | kex_diffie_hellman_cleanup, |
3179 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3180 | | }; |
3181 | | |
3182 | | static const LIBSSH2_KEX_METHOD |
3183 | | kex_method_diffie_helman_group_exchange_sha256 = { |
3184 | | "diffie-hellman-group-exchange-sha256", |
3185 | | kex_method_diffie_hellman_group_exchange_sha256_key_exchange, |
3186 | | kex_diffie_hellman_cleanup, |
3187 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3188 | | }; |
3189 | | |
3190 | | #if LIBSSH2_ECDSA |
3191 | | static const LIBSSH2_KEX_METHOD |
3192 | | kex_method_ecdh_sha2_nistp256 = { |
3193 | | "ecdh-sha2-nistp256", |
3194 | | kex_method_ecdh_key_exchange, |
3195 | | kex_method_ecdh_cleanup, |
3196 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3197 | | }; |
3198 | | |
3199 | | static const LIBSSH2_KEX_METHOD |
3200 | | kex_method_ecdh_sha2_nistp384 = { |
3201 | | "ecdh-sha2-nistp384", |
3202 | | kex_method_ecdh_key_exchange, |
3203 | | kex_method_ecdh_cleanup, |
3204 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3205 | | }; |
3206 | | |
3207 | | static const LIBSSH2_KEX_METHOD |
3208 | | kex_method_ecdh_sha2_nistp521 = { |
3209 | | "ecdh-sha2-nistp521", |
3210 | | kex_method_ecdh_key_exchange, |
3211 | | kex_method_ecdh_cleanup, |
3212 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3213 | | }; |
3214 | | #endif |
3215 | | |
3216 | | #if LIBSSH2_ED25519 |
3217 | | static const LIBSSH2_KEX_METHOD |
3218 | | kex_method_ssh_curve25519_sha256_libssh = { |
3219 | | "curve25519-sha256@libssh.org", |
3220 | | kex_method_curve25519_key_exchange, |
3221 | | kex_method_curve25519_cleanup, |
3222 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3223 | | }; |
3224 | | static const LIBSSH2_KEX_METHOD |
3225 | | kex_method_ssh_curve25519_sha256 = { |
3226 | | "curve25519-sha256", |
3227 | | kex_method_curve25519_key_exchange, |
3228 | | kex_method_curve25519_cleanup, |
3229 | | LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY, |
3230 | | }; |
3231 | | #endif |
3232 | | |
3233 | | /* this kex method signals that client can receive extensions |
3234 | | * as described in https://datatracker.ietf.org/doc/html/rfc8308 |
3235 | | */ |
3236 | | |
3237 | | static const LIBSSH2_KEX_METHOD |
3238 | | kex_method_extension_negotiation = { |
3239 | | "ext-info-c", |
3240 | | NULL, |
3241 | | NULL, |
3242 | | 0, |
3243 | | }; |
3244 | | |
3245 | | static const LIBSSH2_KEX_METHOD |
3246 | | kex_method_strict_client_extension = { |
3247 | | "kex-strict-c-v00@openssh.com", |
3248 | | NULL, |
3249 | | NULL, |
3250 | | 0, |
3251 | | }; |
3252 | | |
3253 | | static const LIBSSH2_KEX_METHOD *libssh2_kex_methods[] = { |
3254 | | #if LIBSSH2_ED25519 |
3255 | | &kex_method_ssh_curve25519_sha256, |
3256 | | &kex_method_ssh_curve25519_sha256_libssh, |
3257 | | #endif |
3258 | | #if LIBSSH2_ECDSA |
3259 | | &kex_method_ecdh_sha2_nistp256, |
3260 | | &kex_method_ecdh_sha2_nistp384, |
3261 | | &kex_method_ecdh_sha2_nistp521, |
3262 | | #endif |
3263 | | &kex_method_diffie_helman_group_exchange_sha256, |
3264 | | &kex_method_diffie_helman_group16_sha512, |
3265 | | &kex_method_diffie_helman_group18_sha512, |
3266 | | &kex_method_diffie_helman_group14_sha256, |
3267 | | &kex_method_diffie_helman_group14_sha1, |
3268 | | &kex_method_diffie_helman_group1_sha1, |
3269 | | &kex_method_diffie_helman_group_exchange_sha1, |
3270 | | &kex_method_extension_negotiation, |
3271 | | &kex_method_strict_client_extension, |
3272 | | NULL |
3273 | | }; |
3274 | | |
3275 | | typedef struct _LIBSSH2_COMMON_METHOD |
3276 | | { |
3277 | | const char *name; |
3278 | | } LIBSSH2_COMMON_METHOD; |
3279 | | |
3280 | | /* kex_method_strlen |
3281 | | * |
3282 | | * Calculate the length of a particular method list's resulting string |
3283 | | * Includes SUM(strlen() of each individual method plus 1 (for coma)) - 1 |
3284 | | * (because the last coma isn't used) |
3285 | | * Another sign of bad coding practices gone mad. Pretend you don't see this. |
3286 | | */ |
3287 | | static size_t |
3288 | | kex_method_strlen(const LIBSSH2_COMMON_METHOD ** method) |
3289 | 60.6k | { |
3290 | 60.6k | size_t len = 0; |
3291 | | |
3292 | 60.6k | if(!method || !*method) { |
3293 | 12.1k | return 0; |
3294 | 12.1k | } |
3295 | | |
3296 | 436k | while(*method && (*method)->name) { |
3297 | 388k | len += strlen((*method)->name) + 1; |
3298 | 388k | method++; |
3299 | 388k | } |
3300 | | |
3301 | 48.5k | return len - 1; |
3302 | 60.6k | } |
3303 | | |
3304 | | |
3305 | | |
3306 | | /* kex_method_list |
3307 | | * Generate formatted preference list in buf |
3308 | | */ |
3309 | | static uint32_t |
3310 | | kex_method_list(unsigned char *buf, uint32_t list_strlen, |
3311 | | const LIBSSH2_COMMON_METHOD ** method) |
3312 | 60.6k | { |
3313 | 60.6k | _libssh2_htonu32(buf, list_strlen); |
3314 | 60.6k | buf += 4; |
3315 | | |
3316 | 60.6k | if(!method || !*method) { |
3317 | 12.1k | return 4; |
3318 | 12.1k | } |
3319 | | |
3320 | 436k | while(*method && (*method)->name) { |
3321 | 388k | uint32_t mlen = (uint32_t)strlen((*method)->name); |
3322 | 388k | memcpy(buf, (*method)->name, mlen); |
3323 | 388k | buf += mlen; |
3324 | 388k | *(buf++) = ','; |
3325 | 388k | method++; |
3326 | 388k | } |
3327 | | |
3328 | 48.5k | return list_strlen + 4; |
3329 | 60.6k | } |
3330 | | |
3331 | | |
3332 | | |
3333 | | #define LIBSSH2_METHOD_PREFS_LEN(prefvar, defaultvar) \ |
3334 | 60.6k | (uint32_t)((prefvar) ? strlen(prefvar) : \ |
3335 | 60.6k | kex_method_strlen((const LIBSSH2_COMMON_METHOD**)(defaultvar))) |
3336 | | |
3337 | | #define LIBSSH2_METHOD_PREFS_STR(buf, prefvarlen, prefvar, defaultvar) \ |
3338 | 60.6k | do { \ |
3339 | 60.6k | if(prefvar) { \ |
3340 | 0 | _libssh2_htonu32((buf), (prefvarlen)); \ |
3341 | 0 | buf += 4; \ |
3342 | 0 | memcpy((buf), (prefvar), (prefvarlen)); \ |
3343 | 0 | buf += (prefvarlen); \ |
3344 | 0 | } \ |
3345 | 60.6k | else { \ |
3346 | 60.6k | buf += kex_method_list((buf), (prefvarlen), \ |
3347 | 60.6k | (const LIBSSH2_COMMON_METHOD**)(defaultvar)); \ |
3348 | 60.6k | } \ |
3349 | 60.6k | } while(0) |
3350 | | |
3351 | | /* kexinit |
3352 | | * Send SSH_MSG_KEXINIT packet |
3353 | | */ |
3354 | | static int kexinit(LIBSSH2_SESSION * session) |
3355 | 6.06k | { |
3356 | | /* 62 = packet_type(1) + cookie(16) + first_packet_follows(1) + |
3357 | | reserved(4) + length longs(40) */ |
3358 | 6.06k | size_t data_len = 62; |
3359 | 6.06k | unsigned char *data, *s; |
3360 | 6.06k | int rc; |
3361 | | |
3362 | 6.06k | if(session->kexinit_state == libssh2_NB_state_idle) { |
3363 | 6.06k | uint32_t kex_len, hostkey_len; |
3364 | 6.06k | uint32_t crypt_cs_len, crypt_sc_len; |
3365 | 6.06k | uint32_t comp_cs_len, comp_sc_len; |
3366 | 6.06k | uint32_t mac_cs_len, mac_sc_len; |
3367 | 6.06k | uint32_t lang_cs_len, lang_sc_len; |
3368 | | |
3369 | 6.06k | kex_len = |
3370 | 6.06k | LIBSSH2_METHOD_PREFS_LEN(session->kex_prefs, libssh2_kex_methods); |
3371 | 6.06k | hostkey_len = |
3372 | 6.06k | LIBSSH2_METHOD_PREFS_LEN(session->hostkey_prefs, |
3373 | 6.06k | libssh2_hostkey_methods()); |
3374 | 6.06k | crypt_cs_len = |
3375 | 6.06k | LIBSSH2_METHOD_PREFS_LEN(session->local.crypt_prefs, |
3376 | 6.06k | libssh2_crypt_methods()); |
3377 | 6.06k | crypt_sc_len = |
3378 | 6.06k | LIBSSH2_METHOD_PREFS_LEN(session->remote.crypt_prefs, |
3379 | 6.06k | libssh2_crypt_methods()); |
3380 | 6.06k | mac_cs_len = |
3381 | 6.06k | LIBSSH2_METHOD_PREFS_LEN(session->local.mac_prefs, |
3382 | 6.06k | _libssh2_mac_methods()); |
3383 | 6.06k | mac_sc_len = |
3384 | 6.06k | LIBSSH2_METHOD_PREFS_LEN(session->remote.mac_prefs, |
3385 | 6.06k | _libssh2_mac_methods()); |
3386 | 6.06k | comp_cs_len = |
3387 | 6.06k | LIBSSH2_METHOD_PREFS_LEN(session->local.comp_prefs, |
3388 | 6.06k | _libssh2_comp_methods(session)); |
3389 | 6.06k | comp_sc_len = |
3390 | 6.06k | LIBSSH2_METHOD_PREFS_LEN(session->remote.comp_prefs, |
3391 | 6.06k | _libssh2_comp_methods(session)); |
3392 | 6.06k | lang_cs_len = |
3393 | 6.06k | LIBSSH2_METHOD_PREFS_LEN(session->local.lang_prefs, NULL); |
3394 | 6.06k | lang_sc_len = |
3395 | 6.06k | LIBSSH2_METHOD_PREFS_LEN(session->remote.lang_prefs, NULL); |
3396 | | |
3397 | 6.06k | data_len += kex_len + hostkey_len + crypt_cs_len + crypt_sc_len + |
3398 | 6.06k | comp_cs_len + comp_sc_len + mac_cs_len + mac_sc_len + |
3399 | 6.06k | lang_cs_len + lang_sc_len; |
3400 | | |
3401 | 6.06k | s = data = LIBSSH2_ALLOC(session, data_len); |
3402 | 6.06k | if(!data) { |
3403 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
3404 | 0 | "Unable to allocate memory"); |
3405 | 0 | } |
3406 | | |
3407 | 6.06k | *(s++) = SSH_MSG_KEXINIT; |
3408 | | |
3409 | 6.06k | if(_libssh2_random(s, 16)) { |
3410 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_RANDGEN, |
3411 | 0 | "Unable to get random bytes " |
3412 | 0 | "for KEXINIT cookie"); |
3413 | 0 | } |
3414 | 6.06k | s += 16; |
3415 | | |
3416 | | /* Ennumerating through these lists twice is probably (certainly?) |
3417 | | inefficient from a CPU standpoint, but it saves multiple |
3418 | | malloc/realloc calls */ |
3419 | 6.06k | LIBSSH2_METHOD_PREFS_STR(s, kex_len, session->kex_prefs, |
3420 | 6.06k | libssh2_kex_methods); |
3421 | 6.06k | LIBSSH2_METHOD_PREFS_STR(s, hostkey_len, session->hostkey_prefs, |
3422 | 6.06k | libssh2_hostkey_methods()); |
3423 | 6.06k | LIBSSH2_METHOD_PREFS_STR(s, crypt_cs_len, session->local.crypt_prefs, |
3424 | 6.06k | libssh2_crypt_methods()); |
3425 | 6.06k | LIBSSH2_METHOD_PREFS_STR(s, crypt_sc_len, session->remote.crypt_prefs, |
3426 | 6.06k | libssh2_crypt_methods()); |
3427 | 6.06k | LIBSSH2_METHOD_PREFS_STR(s, mac_cs_len, session->local.mac_prefs, |
3428 | 6.06k | _libssh2_mac_methods()); |
3429 | 6.06k | LIBSSH2_METHOD_PREFS_STR(s, mac_sc_len, session->remote.mac_prefs, |
3430 | 6.06k | _libssh2_mac_methods()); |
3431 | 6.06k | LIBSSH2_METHOD_PREFS_STR(s, comp_cs_len, session->local.comp_prefs, |
3432 | 6.06k | _libssh2_comp_methods(session)); |
3433 | 6.06k | LIBSSH2_METHOD_PREFS_STR(s, comp_sc_len, session->remote.comp_prefs, |
3434 | 6.06k | _libssh2_comp_methods(session)); |
3435 | 6.06k | LIBSSH2_METHOD_PREFS_STR(s, lang_cs_len, session->local.lang_prefs, |
3436 | 6.06k | NULL); |
3437 | 6.06k | LIBSSH2_METHOD_PREFS_STR(s, lang_sc_len, session->remote.lang_prefs, |
3438 | 6.06k | NULL); |
3439 | | |
3440 | | /* No optimistic KEX packet follows */ |
3441 | | /* Deal with optimistic packets |
3442 | | * session->flags |= KEXINIT_OPTIMISTIC |
3443 | | * session->flags |= KEXINIT_METHODSMATCH |
3444 | | */ |
3445 | 6.06k | *(s++) = 0; |
3446 | | |
3447 | | /* Reserved == 0 */ |
3448 | 6.06k | _libssh2_htonu32(s, 0); |
3449 | | |
3450 | 6.06k | #ifdef LIBSSH2DEBUG |
3451 | 6.06k | { |
3452 | | /* Funnily enough, they'll all "appear" to be '\0' terminated */ |
3453 | 6.06k | unsigned char *p = data + 21; /* type(1) + cookie(16) + len(4) */ |
3454 | | |
3455 | 6.06k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3456 | 6.06k | "Sent KEX: %s", p)); |
3457 | 6.06k | p += kex_len + 4; |
3458 | 6.06k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3459 | 6.06k | "Sent HOSTKEY: %s", p)); |
3460 | 6.06k | p += hostkey_len + 4; |
3461 | 6.06k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3462 | 6.06k | "Sent CRYPT_CS: %s", p)); |
3463 | 6.06k | p += crypt_cs_len + 4; |
3464 | 6.06k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3465 | 6.06k | "Sent CRYPT_SC: %s", p)); |
3466 | 6.06k | p += crypt_sc_len + 4; |
3467 | 6.06k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3468 | 6.06k | "Sent MAC_CS: %s", p)); |
3469 | 6.06k | p += mac_cs_len + 4; |
3470 | 6.06k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3471 | 6.06k | "Sent MAC_SC: %s", p)); |
3472 | 6.06k | p += mac_sc_len + 4; |
3473 | 6.06k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3474 | 6.06k | "Sent COMP_CS: %s", p)); |
3475 | 6.06k | p += comp_cs_len + 4; |
3476 | 6.06k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3477 | 6.06k | "Sent COMP_SC: %s", p)); |
3478 | 6.06k | p += comp_sc_len + 4; |
3479 | 6.06k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3480 | 6.06k | "Sent LANG_CS: %s", p)); |
3481 | 6.06k | p += lang_cs_len + 4; |
3482 | 6.06k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
3483 | 6.06k | "Sent LANG_SC: %s", p)); |
3484 | | /* p += lang_sc_len + 4; */ |
3485 | 6.06k | } |
3486 | 6.06k | #endif /* LIBSSH2DEBUG */ |
3487 | | |
3488 | 6.06k | session->kexinit_state = libssh2_NB_state_created; |
3489 | 6.06k | } |
3490 | 0 | else { |
3491 | 0 | data = session->kexinit_data; |
3492 | 0 | data_len = session->kexinit_data_len; |
3493 | | /* zap the variables to ensure there is NOT a double free later */ |
3494 | 0 | session->kexinit_data = NULL; |
3495 | 0 | session->kexinit_data_len = 0; |
3496 | 0 | } |
3497 | | |
3498 | 6.06k | rc = _libssh2_transport_send(session, data, data_len, NULL, 0); |
3499 | 6.06k | if(rc == LIBSSH2_ERROR_EAGAIN) { |
3500 | 0 | session->kexinit_data = data; |
3501 | 0 | session->kexinit_data_len = data_len; |
3502 | 0 | return rc; |
3503 | 0 | } |
3504 | 6.06k | else if(rc) { |
3505 | 0 | LIBSSH2_FREE(session, data); |
3506 | 0 | session->kexinit_state = libssh2_NB_state_idle; |
3507 | 0 | return _libssh2_error(session, rc, |
3508 | 0 | "Unable to send KEXINIT packet to remote host"); |
3509 | |
|
3510 | 0 | } |
3511 | | |
3512 | 6.06k | if(session->local.kexinit) { |
3513 | 0 | LIBSSH2_FREE(session, session->local.kexinit); |
3514 | 0 | } |
3515 | | |
3516 | 6.06k | session->local.kexinit = data; |
3517 | 6.06k | session->local.kexinit_len = data_len; |
3518 | | |
3519 | 6.06k | session->kexinit_state = libssh2_NB_state_idle; |
3520 | | |
3521 | 6.06k | return 0; |
3522 | 6.06k | } |
3523 | | |
3524 | | /* _libssh2_kex_agree_instr |
3525 | | * Kex specific variant of strstr() |
3526 | | * Needle must be preceded by BOL or ',', and followed by ',' or EOL |
3527 | | */ |
3528 | | unsigned char * |
3529 | | _libssh2_kex_agree_instr(unsigned char *haystack, size_t haystack_len, |
3530 | | const unsigned char *needle, size_t needle_len) |
3531 | 76.9k | { |
3532 | 76.9k | unsigned char *s; |
3533 | 76.9k | unsigned char *end_haystack; |
3534 | 76.9k | size_t left; |
3535 | | |
3536 | 76.9k | if(!haystack || !needle) { |
3537 | 0 | return NULL; |
3538 | 0 | } |
3539 | | |
3540 | | /* Haystack too short to bother trying */ |
3541 | 76.9k | if(haystack_len < needle_len || needle_len == 0) { |
3542 | 7.79k | return NULL; |
3543 | 7.79k | } |
3544 | | |
3545 | 69.1k | s = haystack; |
3546 | 69.1k | end_haystack = &haystack[haystack_len]; |
3547 | 69.1k | left = end_haystack - s; |
3548 | | |
3549 | | /* Needle at start of haystack */ |
3550 | 69.1k | if((strncmp((char *) haystack, (const char *) needle, needle_len) == 0) && |
3551 | 69.1k | (needle_len == haystack_len || haystack[needle_len] == ',')) { |
3552 | 7.73k | return haystack; |
3553 | 7.73k | } |
3554 | | |
3555 | | /* Search until we run out of comas or we run out of haystack, |
3556 | | whichever comes first */ |
3557 | | /* !checksrc! disable EQUALSNULL 1 */ |
3558 | 516k | while((s = (unsigned char *) memchr((char *) s, ',', left)) != NULL) { |
3559 | | /* Advance buffer past coma if we can */ |
3560 | 492k | left = end_haystack - s; |
3561 | 492k | if((left >= 1) && (left <= haystack_len) && (left > needle_len)) { |
3562 | 462k | s++; |
3563 | 462k | left--; |
3564 | 462k | } |
3565 | 30.3k | else { |
3566 | 30.3k | return NULL; |
3567 | 30.3k | } |
3568 | | |
3569 | | /* Needle at X position */ |
3570 | 462k | if((strncmp((char *) s, (const char *) needle, needle_len) == 0) && |
3571 | 462k | (((s - haystack) + needle_len) == haystack_len |
3572 | 8.27k | || s[needle_len] == ',')) { |
3573 | 6.98k | return s; |
3574 | 6.98k | } |
3575 | 462k | } |
3576 | | |
3577 | 24.0k | return NULL; |
3578 | 61.3k | } |
3579 | | |
3580 | | |
3581 | | |
3582 | | /* kex_get_method_by_name |
3583 | | */ |
3584 | | static const LIBSSH2_COMMON_METHOD * |
3585 | | kex_get_method_by_name(const char *name, size_t name_len, |
3586 | | const LIBSSH2_COMMON_METHOD ** methodlist) |
3587 | 0 | { |
3588 | 0 | while(*methodlist) { |
3589 | 0 | if((strlen((*methodlist)->name) == name_len) && |
3590 | 0 | (strncmp((*methodlist)->name, name, name_len) == 0)) { |
3591 | 0 | return *methodlist; |
3592 | 0 | } |
3593 | 0 | methodlist++; |
3594 | 0 | } |
3595 | 0 | return NULL; |
3596 | 0 | } |
3597 | | |
3598 | | |
3599 | | |
3600 | | /* kex_agree_hostkey |
3601 | | * Agree on a Hostkey which works with this kex |
3602 | | */ |
3603 | | static int kex_agree_hostkey(LIBSSH2_SESSION * session, |
3604 | | size_t kex_flags, |
3605 | | unsigned char *hostkey, size_t hostkey_len) |
3606 | 2.45k | { |
3607 | 2.45k | const LIBSSH2_HOSTKEY_METHOD **hostkeyp = libssh2_hostkey_methods(); |
3608 | 2.45k | unsigned char *s; |
3609 | | |
3610 | 2.45k | if(session->hostkey_prefs) { |
3611 | 0 | s = (unsigned char *) session->hostkey_prefs; |
3612 | |
|
3613 | 0 | while(s && *s) { |
3614 | 0 | unsigned char *p = (unsigned char *) strchr((char *) s, ','); |
3615 | 0 | size_t method_len = (p ? (size_t)(p - s) : strlen((char *) s)); |
3616 | 0 | if(_libssh2_kex_agree_instr(hostkey, hostkey_len, s, method_len)) { |
3617 | 0 | const LIBSSH2_HOSTKEY_METHOD *method = |
3618 | 0 | (const LIBSSH2_HOSTKEY_METHOD *) |
3619 | 0 | kex_get_method_by_name((char *) s, method_len, |
3620 | 0 | (const LIBSSH2_COMMON_METHOD **) |
3621 | 0 | hostkeyp); |
3622 | |
|
3623 | 0 | if(!method) { |
3624 | | /* Invalid method -- Should never be reached */ |
3625 | 0 | return -1; |
3626 | 0 | } |
3627 | | |
3628 | | /* So far so good, but does it suit our purposes? (Encrypting |
3629 | | vs Signing) */ |
3630 | 0 | if(((kex_flags & LIBSSH2_KEX_METHOD_FLAG_REQ_ENC_HOSTKEY) == |
3631 | 0 | 0) || (method->encrypt)) { |
3632 | | /* Either this hostkey can do encryption or this kex just |
3633 | | doesn't require it */ |
3634 | 0 | if(((kex_flags & LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY) |
3635 | 0 | == 0) || (method->sig_verify)) { |
3636 | | /* Either this hostkey can do signing or this kex just |
3637 | | doesn't require it */ |
3638 | 0 | session->hostkey = method; |
3639 | 0 | return 0; |
3640 | 0 | } |
3641 | 0 | } |
3642 | 0 | } |
3643 | | |
3644 | 0 | s = p ? p + 1 : NULL; |
3645 | 0 | } |
3646 | 0 | return -1; |
3647 | 0 | } |
3648 | | |
3649 | 22.5k | while(hostkeyp && (*hostkeyp) && (*hostkeyp)->name) { |
3650 | 22.1k | s = _libssh2_kex_agree_instr(hostkey, hostkey_len, |
3651 | 22.1k | (const unsigned char *) (*hostkeyp)->name, |
3652 | 22.1k | strlen((*hostkeyp)->name)); |
3653 | 22.1k | if(s) { |
3654 | | /* So far so good, but does it suit our purposes? (Encrypting vs |
3655 | | Signing) */ |
3656 | 2.20k | if(((kex_flags & LIBSSH2_KEX_METHOD_FLAG_REQ_ENC_HOSTKEY) == 0) || |
3657 | 2.20k | ((*hostkeyp)->encrypt)) { |
3658 | | /* Either this hostkey can do encryption or this kex just |
3659 | | doesn't require it */ |
3660 | 2.20k | if(((kex_flags & LIBSSH2_KEX_METHOD_FLAG_REQ_SIGN_HOSTKEY) == |
3661 | 2.20k | 0) || ((*hostkeyp)->sig_verify)) { |
3662 | | /* Either this hostkey can do signing or this kex just |
3663 | | doesn't require it */ |
3664 | 2.06k | session->hostkey = *hostkeyp; |
3665 | 2.06k | return 0; |
3666 | 2.06k | } |
3667 | 2.20k | } |
3668 | 2.20k | } |
3669 | 20.0k | hostkeyp++; |
3670 | 20.0k | } |
3671 | | |
3672 | 386 | return -1; |
3673 | 2.45k | } |
3674 | | |
3675 | | |
3676 | | |
3677 | | /* kex_agree_kex_hostkey |
3678 | | * Agree on a Key Exchange method and a hostkey encoding type |
3679 | | */ |
3680 | | static int kex_agree_kex_hostkey(LIBSSH2_SESSION * session, unsigned char *kex, |
3681 | | size_t kex_len, unsigned char *hostkey, |
3682 | | size_t hostkey_len) |
3683 | 2.38k | { |
3684 | 2.38k | const LIBSSH2_KEX_METHOD **kexp = libssh2_kex_methods; |
3685 | 2.38k | unsigned char *s; |
3686 | 2.38k | const unsigned char *strict = |
3687 | 2.38k | (const unsigned char *)"kex-strict-s-v00@openssh.com"; |
3688 | | |
3689 | 2.38k | if(_libssh2_kex_agree_instr(kex, kex_len, strict, 28)) { |
3690 | 552 | session->kex_strict = 1; |
3691 | 552 | } |
3692 | | |
3693 | 2.38k | if(session->kex_prefs) { |
3694 | 0 | s = (unsigned char *) session->kex_prefs; |
3695 | |
|
3696 | 0 | while(s && *s) { |
3697 | 0 | unsigned char *q, *p = (unsigned char *) strchr((char *) s, ','); |
3698 | 0 | size_t method_len = (p ? (size_t)(p - s) : strlen((char *) s)); |
3699 | 0 | q = _libssh2_kex_agree_instr(kex, kex_len, s, method_len); |
3700 | 0 | if(q) { |
3701 | 0 | const LIBSSH2_KEX_METHOD *method = (const LIBSSH2_KEX_METHOD *) |
3702 | 0 | kex_get_method_by_name((char *) s, method_len, |
3703 | 0 | (const LIBSSH2_COMMON_METHOD **) |
3704 | 0 | kexp); |
3705 | |
|
3706 | 0 | if(!method) { |
3707 | | /* Invalid method -- Should never be reached */ |
3708 | 0 | return -1; |
3709 | 0 | } |
3710 | | |
3711 | | /* We've agreed on a key exchange method, |
3712 | | * Can we agree on a hostkey that works with this kex? |
3713 | | */ |
3714 | 0 | if(kex_agree_hostkey(session, method->flags, hostkey, |
3715 | 0 | hostkey_len) == 0) { |
3716 | 0 | session->kex = method; |
3717 | 0 | if(session->burn_optimistic_kexinit && (kex == q)) { |
3718 | | /* Server sent an optimistic packet, and client agrees |
3719 | | * with preference cancel burning the first KEX_INIT |
3720 | | * packet that comes in */ |
3721 | 0 | session->burn_optimistic_kexinit = 0; |
3722 | 0 | } |
3723 | 0 | return 0; |
3724 | 0 | } |
3725 | 0 | } |
3726 | | |
3727 | 0 | s = p ? p + 1 : NULL; |
3728 | 0 | } |
3729 | 0 | return -1; |
3730 | 0 | } |
3731 | | |
3732 | 19.7k | while(*kexp && (*kexp)->name) { |
3733 | 19.4k | s = _libssh2_kex_agree_instr(kex, kex_len, |
3734 | 19.4k | (const unsigned char *) (*kexp)->name, |
3735 | 19.4k | strlen((*kexp)->name)); |
3736 | 19.4k | if(s) { |
3737 | | /* We've agreed on a key exchange method, |
3738 | | * Can we agree on a hostkey that works with this kex? |
3739 | | */ |
3740 | 2.45k | if(kex_agree_hostkey(session, (*kexp)->flags, hostkey, |
3741 | 2.45k | hostkey_len) == 0) { |
3742 | 2.06k | session->kex = *kexp; |
3743 | 2.06k | if(session->burn_optimistic_kexinit && (kex == s)) { |
3744 | | /* Server sent an optimistic packet, and client agrees |
3745 | | * with preference cancel burning the first KEX_INIT |
3746 | | * packet that comes in */ |
3747 | 876 | session->burn_optimistic_kexinit = 0; |
3748 | 876 | } |
3749 | 2.06k | return 0; |
3750 | 2.06k | } |
3751 | 2.45k | } |
3752 | 17.4k | kexp++; |
3753 | 17.4k | } |
3754 | 314 | return -1; |
3755 | 2.38k | } |
3756 | | |
3757 | | |
3758 | | |
3759 | | /* kex_agree_crypt |
3760 | | * Agree on a cipher algo |
3761 | | */ |
3762 | | static int kex_agree_crypt(LIBSSH2_SESSION * session, |
3763 | | libssh2_endpoint_data *endpoint, |
3764 | | unsigned char *crypt, |
3765 | | size_t crypt_len) |
3766 | 4.02k | { |
3767 | 4.02k | const LIBSSH2_CRYPT_METHOD **cryptp = libssh2_crypt_methods(); |
3768 | 4.02k | unsigned char *s; |
3769 | | |
3770 | 4.02k | (void)session; |
3771 | | |
3772 | 4.02k | if(endpoint->crypt_prefs) { |
3773 | 0 | s = (unsigned char *) endpoint->crypt_prefs; |
3774 | |
|
3775 | 0 | while(s && *s) { |
3776 | 0 | unsigned char *p = (unsigned char *) strchr((char *) s, ','); |
3777 | 0 | size_t method_len = (p ? (size_t)(p - s) : strlen((char *) s)); |
3778 | |
|
3779 | 0 | if(_libssh2_kex_agree_instr(crypt, crypt_len, s, method_len)) { |
3780 | 0 | const LIBSSH2_CRYPT_METHOD *method = |
3781 | 0 | (const LIBSSH2_CRYPT_METHOD *) |
3782 | 0 | kex_get_method_by_name((char *) s, method_len, |
3783 | 0 | (const LIBSSH2_COMMON_METHOD **) |
3784 | 0 | cryptp); |
3785 | |
|
3786 | 0 | if(!method) { |
3787 | | /* Invalid method -- Should never be reached */ |
3788 | 0 | return -1; |
3789 | 0 | } |
3790 | | |
3791 | 0 | endpoint->crypt = method; |
3792 | 0 | return 0; |
3793 | 0 | } |
3794 | | |
3795 | 0 | s = p ? p + 1 : NULL; |
3796 | 0 | } |
3797 | 0 | return -1; |
3798 | 0 | } |
3799 | | |
3800 | 18.0k | while(*cryptp && (*cryptp)->name) { |
3801 | 17.8k | s = _libssh2_kex_agree_instr(crypt, crypt_len, |
3802 | 17.8k | (const unsigned char *) (*cryptp)->name, |
3803 | 17.8k | strlen((*cryptp)->name)); |
3804 | 17.8k | if(s) { |
3805 | 3.84k | endpoint->crypt = *cryptp; |
3806 | 3.84k | return 0; |
3807 | 3.84k | } |
3808 | 14.0k | cryptp++; |
3809 | 14.0k | } |
3810 | | |
3811 | 182 | return -1; |
3812 | 4.02k | } |
3813 | | |
3814 | | |
3815 | | |
3816 | | /* kex_agree_mac |
3817 | | * Agree on a message authentication hash |
3818 | | */ |
3819 | | static int kex_agree_mac(LIBSSH2_SESSION * session, |
3820 | | libssh2_endpoint_data * endpoint, unsigned char *mac, |
3821 | | size_t mac_len) |
3822 | 3.73k | { |
3823 | 3.73k | const LIBSSH2_MAC_METHOD **macp = _libssh2_mac_methods(); |
3824 | 3.73k | const LIBSSH2_MAC_METHOD *override; |
3825 | 3.73k | unsigned char *s; |
3826 | 3.73k | (void)session; |
3827 | | |
3828 | 3.73k | override = _libssh2_mac_override(endpoint->crypt); |
3829 | 3.73k | if(override) { |
3830 | | /* This crypto method has its own hmac method built-in, so a separate |
3831 | | * negotiation (and use) of a separate hmac method is unnecessary */ |
3832 | 1.72k | endpoint->mac = override; |
3833 | 1.72k | return 0; |
3834 | 1.72k | } |
3835 | | |
3836 | 2.00k | if(endpoint->mac_prefs) { |
3837 | 0 | s = (unsigned char *) endpoint->mac_prefs; |
3838 | |
|
3839 | 0 | while(s && *s) { |
3840 | 0 | unsigned char *p = (unsigned char *) strchr((char *) s, ','); |
3841 | 0 | size_t method_len = (p ? (size_t)(p - s) : strlen((char *) s)); |
3842 | |
|
3843 | 0 | if(_libssh2_kex_agree_instr(mac, mac_len, s, method_len)) { |
3844 | 0 | const LIBSSH2_MAC_METHOD *method = (const LIBSSH2_MAC_METHOD *) |
3845 | 0 | kex_get_method_by_name((char *) s, method_len, |
3846 | 0 | (const LIBSSH2_COMMON_METHOD **) |
3847 | 0 | macp); |
3848 | |
|
3849 | 0 | if(!method) { |
3850 | | /* Invalid method -- Should never be reached */ |
3851 | 0 | return -1; |
3852 | 0 | } |
3853 | | |
3854 | 0 | endpoint->mac = method; |
3855 | 0 | return 0; |
3856 | 0 | } |
3857 | | |
3858 | 0 | s = p ? p + 1 : NULL; |
3859 | 0 | } |
3860 | 0 | return -1; |
3861 | 0 | } |
3862 | | |
3863 | 10.1k | while(*macp && (*macp)->name) { |
3864 | 10.0k | s = _libssh2_kex_agree_instr(mac, mac_len, |
3865 | 10.0k | (const unsigned char *) (*macp)->name, |
3866 | 10.0k | strlen((*macp)->name)); |
3867 | 10.0k | if(s) { |
3868 | 1.91k | endpoint->mac = *macp; |
3869 | 1.91k | return 0; |
3870 | 1.91k | } |
3871 | 8.15k | macp++; |
3872 | 8.15k | } |
3873 | | |
3874 | 95 | return -1; |
3875 | 2.00k | } |
3876 | | |
3877 | | |
3878 | | |
3879 | | /* kex_agree_comp |
3880 | | * Agree on a compression scheme |
3881 | | */ |
3882 | | static int kex_agree_comp(LIBSSH2_SESSION *session, |
3883 | | libssh2_endpoint_data *endpoint, unsigned char *comp, |
3884 | | size_t comp_len) |
3885 | 3.54k | { |
3886 | 3.54k | const LIBSSH2_COMP_METHOD **compp = _libssh2_comp_methods(session); |
3887 | 3.54k | unsigned char *s; |
3888 | 3.54k | (void)session; |
3889 | | |
3890 | 3.54k | if(endpoint->comp_prefs) { |
3891 | 0 | s = (unsigned char *) endpoint->comp_prefs; |
3892 | |
|
3893 | 0 | while(s && *s) { |
3894 | 0 | unsigned char *p = (unsigned char *) strchr((char *) s, ','); |
3895 | 0 | size_t method_len = (p ? (size_t)(p - s) : strlen((char *) s)); |
3896 | |
|
3897 | 0 | if(_libssh2_kex_agree_instr(comp, comp_len, s, method_len)) { |
3898 | 0 | const LIBSSH2_COMP_METHOD *method = |
3899 | 0 | (const LIBSSH2_COMP_METHOD *) |
3900 | 0 | kex_get_method_by_name((char *) s, method_len, |
3901 | 0 | (const LIBSSH2_COMMON_METHOD **) |
3902 | 0 | compp); |
3903 | |
|
3904 | 0 | if(!method) { |
3905 | | /* Invalid method -- Should never be reached */ |
3906 | 0 | return -1; |
3907 | 0 | } |
3908 | | |
3909 | 0 | endpoint->comp = method; |
3910 | 0 | return 0; |
3911 | 0 | } |
3912 | | |
3913 | 0 | s = p ? p + 1 : NULL; |
3914 | 0 | } |
3915 | 0 | return -1; |
3916 | 0 | } |
3917 | | |
3918 | 3.65k | while(*compp && (*compp)->name) { |
3919 | 3.54k | s = _libssh2_kex_agree_instr(comp, comp_len, |
3920 | 3.54k | (const unsigned char *) (*compp)->name, |
3921 | 3.54k | strlen((*compp)->name)); |
3922 | 3.54k | if(s) { |
3923 | 3.43k | endpoint->comp = *compp; |
3924 | 3.43k | return 0; |
3925 | 3.43k | } |
3926 | 110 | compp++; |
3927 | 110 | } |
3928 | | |
3929 | 110 | return -1; |
3930 | 3.54k | } |
3931 | | |
3932 | | |
3933 | | /* TODO: When in server mode we need to turn this logic on its head |
3934 | | * The Client gets to make the final call on "agreed methods" |
3935 | | */ |
3936 | | |
3937 | | /* kex_agree_methods |
3938 | | * Decide which specific method to use of the methods offered by each party |
3939 | | */ |
3940 | | static int kex_agree_methods(LIBSSH2_SESSION * session, unsigned char *data, |
3941 | | size_t data_len) |
3942 | 4.68k | { |
3943 | 4.68k | unsigned char *kex, *hostkey, *crypt_cs, *crypt_sc, *comp_cs, *comp_sc, |
3944 | 4.68k | *mac_cs, *mac_sc; |
3945 | 4.68k | size_t kex_len, hostkey_len, crypt_cs_len, crypt_sc_len, comp_cs_len; |
3946 | 4.68k | size_t comp_sc_len, mac_cs_len, mac_sc_len; |
3947 | 4.68k | struct string_buf buf; |
3948 | | |
3949 | 4.68k | if(data_len < 17) |
3950 | 388 | return -1; |
3951 | | |
3952 | 4.29k | buf.data = (unsigned char *)data; |
3953 | 4.29k | buf.len = data_len; |
3954 | 4.29k | buf.dataptr = buf.data; |
3955 | 4.29k | buf.dataptr++; /* advance past packet type */ |
3956 | | |
3957 | | /* Skip cookie, don't worry, it's preserved in the kexinit field */ |
3958 | 4.29k | buf.dataptr += 16; |
3959 | | |
3960 | | /* Locate each string */ |
3961 | 4.29k | if(_libssh2_get_string(&buf, &kex, &kex_len)) |
3962 | 205 | return -1; |
3963 | 4.09k | if(_libssh2_get_string(&buf, &hostkey, &hostkey_len)) |
3964 | 500 | return -1; |
3965 | 3.59k | if(_libssh2_get_string(&buf, &crypt_cs, &crypt_cs_len)) |
3966 | 137 | return -1; |
3967 | 3.45k | if(_libssh2_get_string(&buf, &crypt_sc, &crypt_sc_len)) |
3968 | 298 | return -1; |
3969 | 3.15k | if(_libssh2_get_string(&buf, &mac_cs, &mac_cs_len)) |
3970 | 242 | return -1; |
3971 | 2.91k | if(_libssh2_get_string(&buf, &mac_sc, &mac_sc_len)) |
3972 | 163 | return -1; |
3973 | 2.75k | if(_libssh2_get_string(&buf, &comp_cs, &comp_cs_len)) |
3974 | 124 | return -1; |
3975 | 2.62k | if(_libssh2_get_string(&buf, &comp_sc, &comp_sc_len)) |
3976 | 144 | return -1; |
3977 | | |
3978 | | /* If the server sent an optimistic packet, assume that it guessed wrong. |
3979 | | * If the guess is determined to be right (by kex_agree_kex_hostkey) |
3980 | | * This flag will be reset to zero so that it's not ignored */ |
3981 | 2.48k | if(_libssh2_check_length(&buf, 1)) { |
3982 | 2.38k | session->burn_optimistic_kexinit = *(buf.dataptr++); |
3983 | 2.38k | } |
3984 | 103 | else { |
3985 | 103 | return -1; |
3986 | 103 | } |
3987 | | |
3988 | | /* Next uint32 in packet is all zeros (reserved) */ |
3989 | | |
3990 | 2.38k | if(kex_agree_kex_hostkey(session, kex, kex_len, hostkey, hostkey_len)) { |
3991 | 314 | return -1; |
3992 | 314 | } |
3993 | | |
3994 | 2.06k | if(kex_agree_crypt(session, &session->local, crypt_cs, crypt_cs_len) |
3995 | 2.06k | || kex_agree_crypt(session, &session->remote, crypt_sc, crypt_sc_len)) { |
3996 | 182 | return -1; |
3997 | 182 | } |
3998 | | |
3999 | | /* This must happen after kex_agree_crypt since some MACs depend on the |
4000 | | negotiated crypto method */ |
4001 | 1.88k | if(kex_agree_mac(session, &session->local, mac_cs, mac_cs_len) |
4002 | 1.88k | || kex_agree_mac(session, &session->remote, mac_sc, mac_sc_len)) { |
4003 | 95 | return -1; |
4004 | 95 | } |
4005 | | |
4006 | 1.78k | if(kex_agree_comp(session, &session->local, comp_cs, comp_cs_len) |
4007 | 1.78k | || kex_agree_comp(session, &session->remote, comp_sc, comp_sc_len)) { |
4008 | 110 | return -1; |
4009 | 110 | } |
4010 | | |
4011 | | #if 0 |
4012 | | if(libssh2_kex_agree_lang(session, &session->local, lang_cs, lang_cs_len) |
4013 | | || libssh2_kex_agree_lang(session, &session->remote, lang_sc, |
4014 | | lang_sc_len)) { |
4015 | | return -1; |
4016 | | } |
4017 | | #endif |
4018 | | |
4019 | 1.67k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
4020 | 1.67k | "Agreed on KEX method: %s", |
4021 | 1.67k | session->kex->name)); |
4022 | 1.67k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
4023 | 1.67k | "Agreed on HOSTKEY method: %s", |
4024 | 1.67k | session->hostkey->name)); |
4025 | 1.67k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
4026 | 1.67k | "Agreed on CRYPT_CS method: %s", |
4027 | 1.67k | session->local.crypt->name)); |
4028 | 1.67k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
4029 | 1.67k | "Agreed on CRYPT_SC method: %s", |
4030 | 1.67k | session->remote.crypt->name)); |
4031 | 1.67k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
4032 | 1.67k | "Agreed on MAC_CS method: %s", |
4033 | 1.67k | session->local.mac->name)); |
4034 | 1.67k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
4035 | 1.67k | "Agreed on MAC_SC method: %s", |
4036 | 1.67k | session->remote.mac->name)); |
4037 | 1.67k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
4038 | 1.67k | "Agreed on COMP_CS method: %s", |
4039 | 1.67k | session->local.comp->name)); |
4040 | 1.67k | _libssh2_debug((session, LIBSSH2_TRACE_KEX, |
4041 | 1.67k | "Agreed on COMP_SC method: %s", |
4042 | 1.67k | session->remote.comp->name)); |
4043 | | |
4044 | 1.67k | return 0; |
4045 | 1.78k | } |
4046 | | |
4047 | | |
4048 | | |
4049 | | /* _libssh2_kex_exchange |
4050 | | * Exchange keys |
4051 | | * Returns 0 on success, non-zero on failure |
4052 | | * |
4053 | | * Returns some errors without _libssh2_error() |
4054 | | */ |
4055 | | int |
4056 | | _libssh2_kex_exchange(LIBSSH2_SESSION * session, int reexchange, |
4057 | | key_exchange_state_t * key_state) |
4058 | 6.07k | { |
4059 | 6.07k | int rc = 0; |
4060 | 6.07k | int retcode; |
4061 | | |
4062 | 6.07k | session->state |= LIBSSH2_STATE_KEX_ACTIVE; |
4063 | | |
4064 | 6.07k | if(key_state->state == libssh2_NB_state_idle) { |
4065 | | /* Prevent loop in packet_add() */ |
4066 | 6.06k | session->state |= LIBSSH2_STATE_EXCHANGING_KEYS; |
4067 | | |
4068 | 6.06k | if(reexchange) { |
4069 | 3.29k | if(session->kex && session->kex->cleanup) { |
4070 | 1.22k | session->kex->cleanup(session, &key_state->key_state_low); |
4071 | 1.22k | } |
4072 | | |
4073 | 3.29k | session->kex = NULL; |
4074 | | |
4075 | 3.29k | if(session->hostkey && session->hostkey->dtor) { |
4076 | 1.23k | session->hostkey->dtor(session, |
4077 | 1.23k | &session->server_hostkey_abstract); |
4078 | 1.23k | } |
4079 | 3.29k | session->hostkey = NULL; |
4080 | 3.29k | } |
4081 | | |
4082 | 6.06k | key_state->state = libssh2_NB_state_created; |
4083 | 6.06k | } |
4084 | | |
4085 | 6.07k | if(!session->kex || !session->hostkey) { |
4086 | 6.07k | if(key_state->state == libssh2_NB_state_created) { |
4087 | | /* Preserve in case of failure */ |
4088 | 6.06k | key_state->oldlocal = session->local.kexinit; |
4089 | 6.06k | key_state->oldlocal_len = session->local.kexinit_len; |
4090 | | |
4091 | 6.06k | session->local.kexinit = NULL; |
4092 | | |
4093 | 6.06k | key_state->state = libssh2_NB_state_sent; |
4094 | 6.06k | } |
4095 | | |
4096 | 6.07k | if(key_state->state == libssh2_NB_state_sent) { |
4097 | 6.06k | retcode = kexinit(session); |
4098 | 6.06k | if(retcode == LIBSSH2_ERROR_EAGAIN) { |
4099 | 0 | session->state &= ~LIBSSH2_STATE_KEX_ACTIVE; |
4100 | 0 | return retcode; |
4101 | 0 | } |
4102 | 6.06k | else if(retcode) { |
4103 | 0 | session->local.kexinit = key_state->oldlocal; |
4104 | 0 | session->local.kexinit_len = key_state->oldlocal_len; |
4105 | 0 | key_state->state = libssh2_NB_state_idle; |
4106 | 0 | session->state &= ~LIBSSH2_STATE_INITIAL_KEX; |
4107 | 0 | session->state &= ~LIBSSH2_STATE_KEX_ACTIVE; |
4108 | 0 | session->state &= ~LIBSSH2_STATE_EXCHANGING_KEYS; |
4109 | 0 | return -1; |
4110 | 0 | } |
4111 | | |
4112 | 6.06k | key_state->state = libssh2_NB_state_sent1; |
4113 | 6.06k | } |
4114 | | |
4115 | 6.07k | if(key_state->state == libssh2_NB_state_sent1) { |
4116 | 6.07k | retcode = |
4117 | 6.07k | _libssh2_packet_require(session, SSH_MSG_KEXINIT, |
4118 | 6.07k | &key_state->data, |
4119 | 6.07k | &key_state->data_len, 0, NULL, 0, |
4120 | 6.07k | &key_state->req_state); |
4121 | 6.07k | if(retcode == LIBSSH2_ERROR_EAGAIN) { |
4122 | 11 | session->state &= ~LIBSSH2_STATE_KEX_ACTIVE; |
4123 | 11 | return retcode; |
4124 | 11 | } |
4125 | 6.06k | else if(retcode) { |
4126 | 1.37k | if(session->local.kexinit) { |
4127 | 1.37k | LIBSSH2_FREE(session, session->local.kexinit); |
4128 | 1.37k | } |
4129 | 1.37k | session->local.kexinit = key_state->oldlocal; |
4130 | 1.37k | session->local.kexinit_len = key_state->oldlocal_len; |
4131 | 1.37k | key_state->state = libssh2_NB_state_idle; |
4132 | 1.37k | session->state &= ~LIBSSH2_STATE_INITIAL_KEX; |
4133 | 1.37k | session->state &= ~LIBSSH2_STATE_KEX_ACTIVE; |
4134 | 1.37k | session->state &= ~LIBSSH2_STATE_EXCHANGING_KEYS; |
4135 | 1.37k | return -1; |
4136 | 1.37k | } |
4137 | | |
4138 | 4.68k | if(session->remote.kexinit) { |
4139 | 258 | LIBSSH2_FREE(session, session->remote.kexinit); |
4140 | 258 | } |
4141 | 4.68k | session->remote.kexinit = key_state->data; |
4142 | 4.68k | session->remote.kexinit_len = key_state->data_len; |
4143 | 4.68k | key_state->data = NULL; |
4144 | | |
4145 | 4.68k | if(kex_agree_methods(session, session->remote.kexinit, |
4146 | 4.68k | session->remote.kexinit_len)) |
4147 | 3.00k | rc = LIBSSH2_ERROR_KEX_FAILURE; |
4148 | | |
4149 | 4.68k | key_state->state = libssh2_NB_state_sent2; |
4150 | 4.68k | } |
4151 | 6.07k | } |
4152 | 0 | else { |
4153 | 0 | key_state->state = libssh2_NB_state_sent2; |
4154 | 0 | } |
4155 | | |
4156 | 4.68k | if(rc == 0 && session->kex) { |
4157 | 1.67k | if(key_state->state == libssh2_NB_state_sent2) { |
4158 | 1.67k | retcode = session->kex->exchange_keys(session, |
4159 | 1.67k | &key_state->key_state_low); |
4160 | 1.67k | if(retcode == LIBSSH2_ERROR_EAGAIN) { |
4161 | 0 | session->state &= ~LIBSSH2_STATE_KEX_ACTIVE; |
4162 | 0 | return retcode; |
4163 | 0 | } |
4164 | 1.67k | else if(retcode) { |
4165 | 1.67k | rc = _libssh2_error(session, |
4166 | 1.67k | LIBSSH2_ERROR_KEY_EXCHANGE_FAILURE, |
4167 | 1.67k | "Unrecoverable error exchanging keys"); |
4168 | 1.67k | } |
4169 | 1.67k | } |
4170 | 1.67k | } |
4171 | | |
4172 | | /* Done with kexinit buffers */ |
4173 | 4.68k | if(session->local.kexinit) { |
4174 | 4.42k | LIBSSH2_FREE(session, session->local.kexinit); |
4175 | 4.42k | session->local.kexinit = NULL; |
4176 | 4.42k | } |
4177 | 4.68k | if(session->remote.kexinit) { |
4178 | 4.42k | LIBSSH2_FREE(session, session->remote.kexinit); |
4179 | 4.42k | session->remote.kexinit = NULL; |
4180 | 4.42k | } |
4181 | | |
4182 | 4.68k | session->state &= ~LIBSSH2_STATE_INITIAL_KEX; |
4183 | 4.68k | session->state &= ~LIBSSH2_STATE_KEX_ACTIVE; |
4184 | 4.68k | session->state &= ~LIBSSH2_STATE_EXCHANGING_KEYS; |
4185 | | |
4186 | 4.68k | key_state->state = libssh2_NB_state_idle; |
4187 | | |
4188 | 4.68k | return rc; |
4189 | 4.68k | } |
4190 | | |
4191 | | |
4192 | | |
4193 | | /* libssh2_session_method_pref |
4194 | | * Set preferred method |
4195 | | */ |
4196 | | LIBSSH2_API int |
4197 | | libssh2_session_method_pref(LIBSSH2_SESSION * session, int method_type, |
4198 | | const char *prefs) |
4199 | 0 | { |
4200 | 0 | char **prefvar, *s, *newprefs; |
4201 | 0 | char *tmpprefs = NULL; |
4202 | 0 | size_t prefs_len = strlen(prefs); |
4203 | 0 | const LIBSSH2_COMMON_METHOD **mlist; |
4204 | |
|
4205 | 0 | switch(method_type) { |
4206 | 0 | case LIBSSH2_METHOD_KEX: |
4207 | 0 | prefvar = &session->kex_prefs; |
4208 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)libssh2_kex_methods; |
4209 | 0 | break; |
4210 | | |
4211 | 0 | case LIBSSH2_METHOD_HOSTKEY: |
4212 | 0 | prefvar = &session->hostkey_prefs; |
4213 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)libssh2_hostkey_methods(); |
4214 | 0 | break; |
4215 | | |
4216 | 0 | case LIBSSH2_METHOD_CRYPT_CS: |
4217 | 0 | prefvar = &session->local.crypt_prefs; |
4218 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)libssh2_crypt_methods(); |
4219 | 0 | break; |
4220 | | |
4221 | 0 | case LIBSSH2_METHOD_CRYPT_SC: |
4222 | 0 | prefvar = &session->remote.crypt_prefs; |
4223 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)libssh2_crypt_methods(); |
4224 | 0 | break; |
4225 | | |
4226 | 0 | case LIBSSH2_METHOD_MAC_CS: |
4227 | 0 | prefvar = &session->local.mac_prefs; |
4228 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)_libssh2_mac_methods(); |
4229 | 0 | break; |
4230 | | |
4231 | 0 | case LIBSSH2_METHOD_MAC_SC: |
4232 | 0 | prefvar = &session->remote.mac_prefs; |
4233 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)_libssh2_mac_methods(); |
4234 | 0 | break; |
4235 | | |
4236 | 0 | case LIBSSH2_METHOD_COMP_CS: |
4237 | 0 | prefvar = &session->local.comp_prefs; |
4238 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)_libssh2_comp_methods(session); |
4239 | 0 | break; |
4240 | | |
4241 | 0 | case LIBSSH2_METHOD_COMP_SC: |
4242 | 0 | prefvar = &session->remote.comp_prefs; |
4243 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)_libssh2_comp_methods(session); |
4244 | 0 | break; |
4245 | | |
4246 | 0 | case LIBSSH2_METHOD_LANG_CS: |
4247 | 0 | prefvar = &session->local.lang_prefs; |
4248 | 0 | mlist = NULL; |
4249 | 0 | break; |
4250 | | |
4251 | 0 | case LIBSSH2_METHOD_LANG_SC: |
4252 | 0 | prefvar = &session->remote.lang_prefs; |
4253 | 0 | mlist = NULL; |
4254 | 0 | break; |
4255 | | |
4256 | 0 | case LIBSSH2_METHOD_SIGN_ALGO: |
4257 | 0 | prefvar = &session->sign_algo_prefs; |
4258 | 0 | mlist = NULL; |
4259 | 0 | break; |
4260 | | |
4261 | 0 | default: |
4262 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_INVAL, |
4263 | 0 | "Invalid parameter specified for method_type"); |
4264 | 0 | } |
4265 | | |
4266 | 0 | s = newprefs = LIBSSH2_ALLOC(session, prefs_len + 1); |
4267 | 0 | if(!newprefs) { |
4268 | 0 | if(tmpprefs) { |
4269 | 0 | LIBSSH2_FREE(session, tmpprefs); |
4270 | 0 | } |
4271 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
4272 | 0 | "Error allocated space for method preferences"); |
4273 | 0 | } |
4274 | 0 | memcpy(s, prefs, prefs_len + 1); |
4275 | |
|
4276 | 0 | while(s && *s && mlist) { |
4277 | 0 | char *p = strchr(s, ','); |
4278 | 0 | size_t method_len = (p ? (size_t)(p - s) : strlen(s)); |
4279 | |
|
4280 | 0 | if(!kex_get_method_by_name(s, method_len, mlist)) { |
4281 | | /* Strip out unsupported method */ |
4282 | 0 | if(p) { |
4283 | 0 | memmove(s, p + 1, strlen(s) - method_len); |
4284 | 0 | } |
4285 | 0 | else { |
4286 | 0 | if(s > newprefs) { |
4287 | 0 | *(--s) = '\0'; |
4288 | 0 | } |
4289 | 0 | else { |
4290 | 0 | *s = '\0'; |
4291 | 0 | } |
4292 | 0 | } |
4293 | 0 | } |
4294 | 0 | else { |
4295 | 0 | s = p ? (p + 1) : NULL; |
4296 | 0 | } |
4297 | 0 | } |
4298 | |
|
4299 | 0 | if(tmpprefs) { |
4300 | 0 | LIBSSH2_FREE(session, tmpprefs); |
4301 | 0 | } |
4302 | |
|
4303 | 0 | if(!*newprefs) { |
4304 | 0 | LIBSSH2_FREE(session, newprefs); |
4305 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_METHOD_NOT_SUPPORTED, |
4306 | 0 | "The requested method(s) are not currently " |
4307 | 0 | "supported"); |
4308 | 0 | } |
4309 | | |
4310 | | /* add method kex extension to the start of the user list */ |
4311 | 0 | if(method_type == LIBSSH2_METHOD_KEX) { |
4312 | 0 | const char *kex_extensions = |
4313 | 0 | "ext-info-c,kex-strict-c-v00@openssh.com,"; |
4314 | 0 | size_t kex_extensions_len = strlen(kex_extensions); |
4315 | 0 | size_t tmp_len = kex_extensions_len + strlen(newprefs); |
4316 | 0 | tmpprefs = LIBSSH2_ALLOC(session, tmp_len + 1); |
4317 | 0 | if(!tmpprefs) { |
4318 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
4319 | 0 | "Error allocated space for kex method" |
4320 | 0 | " preferences"); |
4321 | 0 | } |
4322 | | |
4323 | 0 | memcpy(tmpprefs, kex_extensions, kex_extensions_len); |
4324 | 0 | memcpy(tmpprefs + kex_extensions_len, newprefs, strlen(newprefs)); |
4325 | 0 | tmpprefs[tmp_len] = '\0'; |
4326 | |
|
4327 | 0 | LIBSSH2_FREE(session, newprefs); |
4328 | 0 | newprefs = tmpprefs; |
4329 | 0 | } |
4330 | | |
4331 | 0 | if(*prefvar) { |
4332 | 0 | LIBSSH2_FREE(session, *prefvar); |
4333 | 0 | } |
4334 | 0 | *prefvar = newprefs; |
4335 | |
|
4336 | 0 | return 0; |
4337 | 0 | } |
4338 | | |
4339 | | /* |
4340 | | * libssh2_session_supported_algs |
4341 | | * returns a number of returned algorithms (a positive number) on success, |
4342 | | * a negative number on failure |
4343 | | */ |
4344 | | |
4345 | | LIBSSH2_API int libssh2_session_supported_algs(LIBSSH2_SESSION* session, |
4346 | | int method_type, |
4347 | | const char ***algs) |
4348 | 0 | { |
4349 | 0 | unsigned int i; |
4350 | 0 | unsigned int j; |
4351 | 0 | unsigned int ialg; |
4352 | 0 | const LIBSSH2_COMMON_METHOD **mlist; |
4353 | | |
4354 | | /* to prevent coredumps due to dereferencing of NULL */ |
4355 | 0 | if(!algs) |
4356 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_BAD_USE, |
4357 | 0 | "algs must not be NULL"); |
4358 | | |
4359 | 0 | switch(method_type) { |
4360 | 0 | case LIBSSH2_METHOD_KEX: |
4361 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)libssh2_kex_methods; |
4362 | 0 | break; |
4363 | | |
4364 | 0 | case LIBSSH2_METHOD_HOSTKEY: |
4365 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)libssh2_hostkey_methods(); |
4366 | 0 | break; |
4367 | | |
4368 | 0 | case LIBSSH2_METHOD_CRYPT_CS: |
4369 | 0 | case LIBSSH2_METHOD_CRYPT_SC: |
4370 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)libssh2_crypt_methods(); |
4371 | 0 | break; |
4372 | | |
4373 | 0 | case LIBSSH2_METHOD_MAC_CS: |
4374 | 0 | case LIBSSH2_METHOD_MAC_SC: |
4375 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)_libssh2_mac_methods(); |
4376 | 0 | break; |
4377 | | |
4378 | 0 | case LIBSSH2_METHOD_COMP_CS: |
4379 | 0 | case LIBSSH2_METHOD_COMP_SC: |
4380 | 0 | mlist = (const LIBSSH2_COMMON_METHOD **)_libssh2_comp_methods(session); |
4381 | 0 | break; |
4382 | | |
4383 | 0 | case LIBSSH2_METHOD_SIGN_ALGO: |
4384 | | /* no built-in supported list due to backend support */ |
4385 | 0 | mlist = NULL; |
4386 | 0 | break; |
4387 | | |
4388 | 0 | default: |
4389 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_METHOD_NOT_SUPPORTED, |
4390 | 0 | "Unknown method type"); |
4391 | 0 | } /* switch */ |
4392 | | |
4393 | | /* weird situation */ |
4394 | 0 | if(!mlist) |
4395 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_INVAL, |
4396 | 0 | "No algorithm found"); |
4397 | | |
4398 | | /* |
4399 | | mlist is looped through twice. The first time to find the number od |
4400 | | supported algorithms (needed to allocate the proper size of array) and |
4401 | | the second time to actually copy the pointers. Typically this function |
4402 | | will not be called often (typically at the beginning of a session) and |
4403 | | the number of algorithms (i.e. number of iterations in one loop) will |
4404 | | not be high (typically it will not exceed 20) for quite a long time. |
4405 | | |
4406 | | So double looping really shouldn't be an issue and it is definitely a |
4407 | | better solution than reallocation several times. |
4408 | | */ |
4409 | | |
4410 | | /* count the number of supported algorithms */ |
4411 | 0 | for(i = 0, ialg = 0; mlist[i]; i++) { |
4412 | | /* do not count fields with NULL name */ |
4413 | 0 | if(mlist[i]->name) |
4414 | 0 | ialg++; |
4415 | 0 | } |
4416 | | |
4417 | | /* weird situation, no algorithm found */ |
4418 | 0 | if(ialg == 0) |
4419 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_INVAL, |
4420 | 0 | "No algorithm found"); |
4421 | | |
4422 | | /* allocate buffer */ |
4423 | 0 | *algs = (const char **) LIBSSH2_ALLOC(session, ialg*sizeof(const char *)); |
4424 | 0 | if(!*algs) { |
4425 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
4426 | 0 | "Memory allocation failed"); |
4427 | 0 | } |
4428 | | /* Past this point *algs must be deallocated in case of an error! */ |
4429 | | |
4430 | | /* copy non-NULL pointers only */ |
4431 | 0 | for(i = 0, j = 0; mlist[i] && j < ialg; i++) { |
4432 | 0 | if(!mlist[i]->name) { |
4433 | | /* maybe a weird situation but if it occurs, do not include NULL |
4434 | | pointers */ |
4435 | 0 | continue; |
4436 | 0 | } |
4437 | | |
4438 | | /* note that [] has higher priority than * (dereferencing) */ |
4439 | 0 | (*algs)[j++] = mlist[i]->name; |
4440 | 0 | } |
4441 | | |
4442 | | /* correct number of pointers copied? (test the code above) */ |
4443 | 0 | if(j != ialg) { |
4444 | | /* deallocate buffer */ |
4445 | 0 | LIBSSH2_FREE(session, (void *)*algs); |
4446 | 0 | *algs = NULL; |
4447 | |
|
4448 | 0 | return _libssh2_error(session, LIBSSH2_ERROR_BAD_USE, |
4449 | 0 | "Internal error"); |
4450 | 0 | } |
4451 | | |
4452 | 0 | return ialg; |
4453 | 0 | } |