/src/strongswan/src/libstrongswan/plugins/pgp/pgp_cert.c
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1 | | /* |
2 | | * Copyright (C) 2009 Martin Willi |
3 | | * |
4 | | * Copyright (C) secunet Security Networks AG |
5 | | * |
6 | | * This program is free software; you can redistribute it and/or modify it |
7 | | * under the terms of the GNU General Public License as published by the |
8 | | * Free Software Foundation; either version 2 of the License, or (at your |
9 | | * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. |
10 | | * |
11 | | * This program is distributed in the hope that it will be useful, but |
12 | | * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
13 | | * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | | * for more details. |
15 | | */ |
16 | | |
17 | | #include "pgp_cert.h" |
18 | | #include "pgp_utils.h" |
19 | | |
20 | | #include <time.h> |
21 | | |
22 | | #include <utils/debug.h> |
23 | | |
24 | | typedef struct private_pgp_cert_t private_pgp_cert_t; |
25 | | |
26 | | /** |
27 | | * Private data of an pgp_cert_t object. |
28 | | */ |
29 | | struct private_pgp_cert_t { |
30 | | |
31 | | /** |
32 | | * Implements pgp_cert_t interface. |
33 | | */ |
34 | | pgp_cert_t public; |
35 | | |
36 | | /** |
37 | | * Public key of the certificate |
38 | | */ |
39 | | public_key_t *key; |
40 | | |
41 | | /** |
42 | | * version of the public key |
43 | | */ |
44 | | uint32_t version; |
45 | | |
46 | | /** |
47 | | * creation time |
48 | | */ |
49 | | uint32_t created; |
50 | | |
51 | | /** |
52 | | * days the certificate is valid |
53 | | */ |
54 | | uint32_t valid; |
55 | | |
56 | | /** |
57 | | * userid of the certificate |
58 | | */ |
59 | | identification_t *user_id; |
60 | | |
61 | | /** |
62 | | * v3 or v4 fingerprint of the PGP public key |
63 | | */ |
64 | | chunk_t fingerprint; |
65 | | |
66 | | /** |
67 | | * full PGP encoding |
68 | | */ |
69 | | chunk_t encoding; |
70 | | |
71 | | /** |
72 | | * reference counter |
73 | | */ |
74 | | refcount_t ref; |
75 | | }; |
76 | | |
77 | | |
78 | | METHOD(certificate_t, get_type, certificate_type_t, |
79 | | private_pgp_cert_t *this) |
80 | 0 | { |
81 | 0 | return CERT_GPG; |
82 | 0 | } |
83 | | |
84 | | METHOD(certificate_t, get_subject,identification_t*, |
85 | | private_pgp_cert_t *this) |
86 | 0 | { |
87 | 0 | return this->user_id; |
88 | 0 | } |
89 | | |
90 | | METHOD(certificate_t, get_issuer, identification_t*, |
91 | | private_pgp_cert_t *this) |
92 | 0 | { |
93 | 0 | return this->user_id; |
94 | 0 | } |
95 | | |
96 | | METHOD(certificate_t, has_subject, id_match_t, |
97 | | private_pgp_cert_t *this, identification_t *subject) |
98 | 0 | { |
99 | 0 | id_match_t match_user_id; |
100 | |
|
101 | 0 | match_user_id = this->user_id->matches(this->user_id, subject); |
102 | 0 | if (match_user_id == ID_MATCH_NONE && |
103 | 0 | subject->get_type(subject) == ID_KEY_ID && |
104 | 0 | chunk_equals(this->fingerprint, subject->get_encoding(subject))) |
105 | 0 | { |
106 | 0 | return ID_MATCH_PERFECT; |
107 | 0 | } |
108 | 0 | return match_user_id; |
109 | 0 | } |
110 | | |
111 | | METHOD(certificate_t, has_issuer, id_match_t, |
112 | | private_pgp_cert_t *this, identification_t *issuer) |
113 | 0 | { |
114 | 0 | return ID_MATCH_NONE; |
115 | 0 | } |
116 | | |
117 | | METHOD(certificate_t, issued_by,bool, |
118 | | private_pgp_cert_t *this, certificate_t *issuer, signature_params_t **scheme) |
119 | 0 | { |
120 | | /* TODO: check signature blobs for a valid signature */ |
121 | 0 | return FALSE; |
122 | 0 | } |
123 | | |
124 | | METHOD(certificate_t, get_public_key, public_key_t*, |
125 | | private_pgp_cert_t *this) |
126 | 0 | { |
127 | 0 | this->key->get_ref(this->key); |
128 | 0 | return this->key; |
129 | 0 | } |
130 | | |
131 | | METHOD(certificate_t, get_ref, certificate_t*, |
132 | | private_pgp_cert_t *this) |
133 | 0 | { |
134 | 0 | ref_get(&this->ref); |
135 | 0 | return &this->public.interface.interface; |
136 | 0 | } |
137 | | |
138 | | METHOD(certificate_t, get_validity, bool, |
139 | | private_pgp_cert_t *this, time_t *when, time_t *not_before, |
140 | | time_t *not_after) |
141 | 0 | { |
142 | 0 | time_t t, until; |
143 | 0 | uint64_t expiry = 0; |
144 | |
|
145 | 0 | if (when) |
146 | 0 | { |
147 | 0 | t = *when; |
148 | 0 | } |
149 | 0 | else |
150 | 0 | { |
151 | 0 | t = time(NULL); |
152 | 0 | } |
153 | 0 | if (not_before) |
154 | 0 | { |
155 | 0 | *not_before = this->created; |
156 | 0 | } |
157 | 0 | if (this->valid) |
158 | 0 | { |
159 | 0 | expiry = this->created + this->valid * 24 * 60 * 60; |
160 | 0 | } |
161 | 0 | if (!expiry || (sizeof(time_t) == 4 && expiry > TIME_32_BIT_SIGNED_MAX)) |
162 | 0 | { |
163 | | /* Jan 19 03:14:07 UTC 2038 */ |
164 | 0 | until = TIME_32_BIT_SIGNED_MAX; |
165 | 0 | } |
166 | 0 | else |
167 | 0 | { |
168 | 0 | until = expiry; |
169 | 0 | } |
170 | 0 | if (not_after) |
171 | 0 | { |
172 | 0 | *not_after = until; |
173 | 0 | } |
174 | 0 | return (t >= this->created && t <= until); |
175 | 0 | } |
176 | | |
177 | | METHOD(certificate_t, get_encoding, bool, |
178 | | private_pgp_cert_t *this, cred_encoding_type_t type, chunk_t *encoding) |
179 | 0 | { |
180 | 0 | if (type == CERT_PGP_PKT) |
181 | 0 | { |
182 | 0 | *encoding = chunk_clone(this->encoding); |
183 | 0 | return TRUE; |
184 | 0 | } |
185 | 0 | return lib->encoding->encode(lib->encoding, type, NULL, encoding, |
186 | 0 | CRED_PART_PGP_CERT, this->encoding, CRED_PART_END); |
187 | 0 | } |
188 | | |
189 | | METHOD(certificate_t, equals, bool, |
190 | | private_pgp_cert_t *this, certificate_t *other) |
191 | 0 | { |
192 | 0 | chunk_t encoding; |
193 | 0 | bool equal; |
194 | |
|
195 | 0 | if (this == (private_pgp_cert_t*)other) |
196 | 0 | { |
197 | 0 | return TRUE; |
198 | 0 | } |
199 | 0 | if (other->get_type(other) != CERT_X509) |
200 | 0 | { |
201 | 0 | return FALSE; |
202 | 0 | } |
203 | 0 | if (other->equals == (void*)equals) |
204 | 0 | { /* skip allocation if we have the same implementation */ |
205 | 0 | return chunk_equals(this->encoding, ((private_pgp_cert_t*)other)->encoding); |
206 | 0 | } |
207 | 0 | if (!other->get_encoding(other, CERT_PGP_PKT, &encoding)) |
208 | 0 | { |
209 | 0 | return FALSE; |
210 | 0 | } |
211 | 0 | equal = chunk_equals(this->encoding, encoding); |
212 | 0 | free(encoding.ptr); |
213 | 0 | return equal; |
214 | 0 | } |
215 | | |
216 | | METHOD(certificate_t, destroy, void, |
217 | | private_pgp_cert_t *this) |
218 | 0 | { |
219 | 0 | if (ref_put(&this->ref)) |
220 | 0 | { |
221 | 0 | DESTROY_IF(this->key); |
222 | 0 | DESTROY_IF(this->user_id); |
223 | 0 | free(this->fingerprint.ptr); |
224 | 0 | free(this->encoding.ptr); |
225 | 0 | free(this); |
226 | 0 | } |
227 | 0 | } |
228 | | |
229 | | METHOD(pgp_certificate_t, get_fingerprint, chunk_t, |
230 | | private_pgp_cert_t *this) |
231 | 0 | { |
232 | 0 | return this->fingerprint; |
233 | 0 | } |
234 | | |
235 | | /** |
236 | | * See header |
237 | | */ |
238 | | private_pgp_cert_t *create_empty() |
239 | 0 | { |
240 | 0 | private_pgp_cert_t *this; |
241 | |
|
242 | 0 | INIT(this, |
243 | 0 | .public = { |
244 | 0 | .interface = { |
245 | 0 | .interface = { |
246 | 0 | .get_type = _get_type, |
247 | 0 | .get_subject = _get_subject, |
248 | 0 | .get_issuer = _get_issuer, |
249 | 0 | .has_subject = _has_subject, |
250 | 0 | .has_issuer = _has_issuer, |
251 | 0 | .issued_by = _issued_by, |
252 | 0 | .get_public_key = _get_public_key, |
253 | 0 | .get_validity = _get_validity, |
254 | 0 | .get_encoding = _get_encoding, |
255 | 0 | .equals = _equals, |
256 | 0 | .get_ref = _get_ref, |
257 | 0 | .destroy = _destroy, |
258 | 0 | }, |
259 | 0 | .get_fingerprint = _get_fingerprint, |
260 | 0 | }, |
261 | 0 | }, |
262 | 0 | .ref = 1, |
263 | 0 | ); |
264 | |
|
265 | 0 | return this; |
266 | 0 | } |
267 | | |
268 | | /** |
269 | | * Parse the public key packet of a PGP certificate |
270 | | */ |
271 | | static bool parse_public_key(private_pgp_cert_t *this, chunk_t packet) |
272 | 0 | { |
273 | 0 | chunk_t pubkey_packet = packet; |
274 | |
|
275 | 0 | if (!pgp_read_scalar(&packet, 1, &this->version)) |
276 | 0 | { |
277 | 0 | return FALSE; |
278 | 0 | } |
279 | 0 | switch (this->version) |
280 | 0 | { |
281 | 0 | case 3: |
282 | 0 | if (!pgp_read_scalar(&packet, 4, &this->created) || |
283 | 0 | !pgp_read_scalar(&packet, 2, &this->valid)) |
284 | 0 | { |
285 | 0 | return FALSE; |
286 | 0 | } |
287 | 0 | break; |
288 | 0 | case 4: |
289 | 0 | if (!pgp_read_scalar(&packet, 4, &this->created)) |
290 | 0 | { |
291 | 0 | return FALSE; |
292 | 0 | } |
293 | 0 | break; |
294 | 0 | default: |
295 | 0 | DBG1(DBG_ASN, "PGP packet version V%d not supported", |
296 | 0 | this->version); |
297 | 0 | return FALSE; |
298 | 0 | } |
299 | 0 | if (this->valid) |
300 | 0 | { |
301 | 0 | DBG2(DBG_ASN, "L2 - created %T, valid %d days", &this->created, FALSE, |
302 | 0 | this->valid); |
303 | 0 | } |
304 | 0 | else |
305 | 0 | { |
306 | 0 | DBG2(DBG_ASN, "L2 - created %T, never expires", &this->created, FALSE); |
307 | 0 | } |
308 | 0 | DESTROY_IF(this->key); |
309 | 0 | this->key = lib->creds->create(lib->creds, CRED_PUBLIC_KEY, KEY_ANY, |
310 | 0 | BUILD_BLOB_PGP, packet, BUILD_END); |
311 | 0 | if (this->key == NULL) |
312 | 0 | { |
313 | 0 | return FALSE; |
314 | 0 | } |
315 | | |
316 | | /* compute V4 or V3 fingerprint according to section 12.2 of RFC 4880 */ |
317 | 0 | if (this->version == 4) |
318 | 0 | { |
319 | 0 | chunk_t pubkey_packet_header = chunk_from_chars( |
320 | 0 | 0x99, pubkey_packet.len / 256, pubkey_packet.len % 256 |
321 | 0 | ); |
322 | 0 | hasher_t *hasher; |
323 | |
|
324 | 0 | hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA1); |
325 | 0 | if (hasher == NULL) |
326 | 0 | { |
327 | 0 | DBG1(DBG_ASN, "no SHA-1 hasher available"); |
328 | 0 | return FALSE; |
329 | 0 | } |
330 | 0 | if (!hasher->allocate_hash(hasher, pubkey_packet_header, NULL) || |
331 | 0 | !hasher->allocate_hash(hasher, pubkey_packet, &this->fingerprint)) |
332 | 0 | { |
333 | 0 | hasher->destroy(hasher); |
334 | 0 | return FALSE; |
335 | 0 | } |
336 | 0 | hasher->destroy(hasher); |
337 | 0 | DBG2(DBG_ASN, "L2 - v4 fingerprint %#B", &this->fingerprint); |
338 | 0 | } |
339 | 0 | else |
340 | 0 | { |
341 | | /* V3 fingerprint is computed by public_key_t class */ |
342 | 0 | if (!this->key->get_fingerprint(this->key, KEYID_PGPV3, |
343 | 0 | &this->fingerprint)) |
344 | 0 | { |
345 | 0 | return FALSE; |
346 | 0 | } |
347 | 0 | this->fingerprint = chunk_clone(this->fingerprint); |
348 | 0 | DBG2(DBG_ASN, "L2 - v3 fingerprint %#B", &this->fingerprint); |
349 | 0 | } |
350 | 0 | return TRUE; |
351 | 0 | } |
352 | | |
353 | | /** |
354 | | * Parse the signature packet of a PGP certificate |
355 | | */ |
356 | | static bool parse_signature(private_pgp_cert_t *this, chunk_t packet) |
357 | 0 | { |
358 | 0 | uint32_t version, len, type, created; |
359 | |
|
360 | 0 | if (!pgp_read_scalar(&packet, 1, &version)) |
361 | 0 | { |
362 | 0 | return FALSE; |
363 | 0 | } |
364 | | |
365 | | /* we parse only v3 or v4 signature packets */ |
366 | 0 | if (version != 3 && version != 4) |
367 | 0 | { |
368 | 0 | DBG2(DBG_ASN, "L2 - v%d signature ignored", version); |
369 | 0 | return TRUE; |
370 | 0 | } |
371 | 0 | if (version == 4) |
372 | 0 | { |
373 | 0 | if (!pgp_read_scalar(&packet, 1, &type)) |
374 | 0 | { |
375 | 0 | return FALSE; |
376 | 0 | } |
377 | 0 | DBG2(DBG_ASN, "L2 - v%d signature of type 0x%02x", version, type); |
378 | 0 | } |
379 | 0 | else |
380 | 0 | { |
381 | 0 | if (!pgp_read_scalar(&packet, 1, &len) || len != 5) |
382 | 0 | { |
383 | 0 | return FALSE; |
384 | 0 | } |
385 | 0 | if (!pgp_read_scalar(&packet, 1, &type) || |
386 | 0 | !pgp_read_scalar(&packet, 4, &created)) |
387 | 0 | { |
388 | 0 | return FALSE; |
389 | 0 | } |
390 | 0 | DBG2(DBG_ASN, "L2 - v3 signature of type 0x%02x, created %T", type, |
391 | 0 | &created, FALSE); |
392 | 0 | } |
393 | | /* TODO: parse and save signature to a list */ |
394 | 0 | return TRUE; |
395 | 0 | } |
396 | | |
397 | | /** |
398 | | * Parse the userid packet of a PGP certificate |
399 | | */ |
400 | | static bool parse_user_id(private_pgp_cert_t *this, chunk_t packet) |
401 | 0 | { |
402 | 0 | DESTROY_IF(this->user_id); |
403 | 0 | this->user_id = identification_create_from_encoding(ID_KEY_ID, packet); |
404 | 0 | DBG2(DBG_ASN, "L2 - '%Y'", this->user_id); |
405 | 0 | return TRUE; |
406 | 0 | } |
407 | | |
408 | | /** |
409 | | * See header. |
410 | | */ |
411 | | pgp_cert_t *pgp_cert_load(certificate_type_t type, va_list args) |
412 | 0 | { |
413 | 0 | chunk_t packet, blob = chunk_empty; |
414 | 0 | pgp_packet_tag_t tag; |
415 | 0 | private_pgp_cert_t *this; |
416 | |
|
417 | 0 | while (TRUE) |
418 | 0 | { |
419 | 0 | switch (va_arg(args, builder_part_t)) |
420 | 0 | { |
421 | 0 | case BUILD_BLOB_PGP: |
422 | 0 | blob = va_arg(args, chunk_t); |
423 | 0 | continue; |
424 | 0 | case BUILD_END: |
425 | 0 | break; |
426 | 0 | default: |
427 | 0 | return NULL; |
428 | 0 | } |
429 | 0 | break; |
430 | 0 | } |
431 | | |
432 | 0 | this = create_empty(); |
433 | 0 | this->encoding = chunk_clone(blob); |
434 | 0 | while (blob.len) |
435 | 0 | { |
436 | 0 | if (!pgp_read_packet(&blob, &packet, &tag)) |
437 | 0 | { |
438 | 0 | destroy(this); |
439 | 0 | return NULL; |
440 | 0 | } |
441 | 0 | switch (tag) |
442 | 0 | { |
443 | 0 | case PGP_PKT_PUBLIC_KEY: |
444 | 0 | if (!parse_public_key(this, packet)) |
445 | 0 | { |
446 | 0 | destroy(this); |
447 | 0 | return NULL; |
448 | 0 | } |
449 | 0 | break; |
450 | 0 | case PGP_PKT_SIGNATURE: |
451 | 0 | if (!parse_signature(this, packet)) |
452 | 0 | { |
453 | 0 | destroy(this); |
454 | 0 | return NULL; |
455 | 0 | } |
456 | 0 | break; |
457 | 0 | case PGP_PKT_USER_ID: |
458 | 0 | if (!parse_user_id(this, packet)) |
459 | 0 | { |
460 | 0 | destroy(this); |
461 | 0 | return NULL; |
462 | 0 | } |
463 | 0 | break; |
464 | 0 | default: |
465 | 0 | DBG1(DBG_LIB, "ignoring %N packet in PGP certificate", |
466 | 0 | pgp_packet_tag_names, tag); |
467 | 0 | break; |
468 | 0 | } |
469 | 0 | } |
470 | 0 | if (this->key) |
471 | 0 | { |
472 | 0 | return &this->public; |
473 | 0 | } |
474 | 0 | destroy(this); |
475 | | return NULL; |
476 | 0 | } |
477 | | |