/src/boringssl/crypto/fipsmodule/rsa/rsa_impl.c.inc
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1 | | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
2 | | * All rights reserved. |
3 | | * |
4 | | * This package is an SSL implementation written |
5 | | * by Eric Young (eay@cryptsoft.com). |
6 | | * The implementation was written so as to conform with Netscapes SSL. |
7 | | * |
8 | | * This library is free for commercial and non-commercial use as long as |
9 | | * the following conditions are aheared to. The following conditions |
10 | | * apply to all code found in this distribution, be it the RC4, RSA, |
11 | | * lhash, DES, etc., code; not just the SSL code. The SSL documentation |
12 | | * included with this distribution is covered by the same copyright terms |
13 | | * except that the holder is Tim Hudson (tjh@cryptsoft.com). |
14 | | * |
15 | | * Copyright remains Eric Young's, and as such any Copyright notices in |
16 | | * the code are not to be removed. |
17 | | * If this package is used in a product, Eric Young should be given attribution |
18 | | * as the author of the parts of the library used. |
19 | | * This can be in the form of a textual message at program startup or |
20 | | * in documentation (online or textual) provided with the package. |
21 | | * |
22 | | * Redistribution and use in source and binary forms, with or without |
23 | | * modification, are permitted provided that the following conditions |
24 | | * are met: |
25 | | * 1. Redistributions of source code must retain the copyright |
26 | | * notice, this list of conditions and the following disclaimer. |
27 | | * 2. Redistributions in binary form must reproduce the above copyright |
28 | | * notice, this list of conditions and the following disclaimer in the |
29 | | * documentation and/or other materials provided with the distribution. |
30 | | * 3. All advertising materials mentioning features or use of this software |
31 | | * must display the following acknowledgement: |
32 | | * "This product includes cryptographic software written by |
33 | | * Eric Young (eay@cryptsoft.com)" |
34 | | * The word 'cryptographic' can be left out if the rouines from the library |
35 | | * being used are not cryptographic related :-). |
36 | | * 4. If you include any Windows specific code (or a derivative thereof) from |
37 | | * the apps directory (application code) you must include an acknowledgement: |
38 | | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
39 | | * |
40 | | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
41 | | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
42 | | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
43 | | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
44 | | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
45 | | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
46 | | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
47 | | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
48 | | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
49 | | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
50 | | * SUCH DAMAGE. |
51 | | * |
52 | | * The licence and distribution terms for any publically available version or |
53 | | * derivative of this code cannot be changed. i.e. this code cannot simply be |
54 | | * copied and put under another distribution licence |
55 | | * [including the GNU Public Licence.] */ |
56 | | |
57 | | #include <openssl/rsa.h> |
58 | | |
59 | | #include <assert.h> |
60 | | #include <limits.h> |
61 | | #include <string.h> |
62 | | |
63 | | #include <openssl/bn.h> |
64 | | #include <openssl/err.h> |
65 | | #include <openssl/mem.h> |
66 | | #include <openssl/thread.h> |
67 | | |
68 | | #include "../../bcm_support.h" |
69 | | #include "../../internal.h" |
70 | | #include "../bn/internal.h" |
71 | | #include "../delocate.h" |
72 | | #include "../service_indicator/internal.h" |
73 | | #include "internal.h" |
74 | | |
75 | | |
76 | 0 | int rsa_check_public_key(const RSA *rsa) { |
77 | 0 | if (rsa->n == NULL) { |
78 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING); |
79 | 0 | return 0; |
80 | 0 | } |
81 | | |
82 | 0 | unsigned n_bits = BN_num_bits(rsa->n); |
83 | 0 | if (n_bits > OPENSSL_RSA_MAX_MODULUS_BITS) { |
84 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_MODULUS_TOO_LARGE); |
85 | 0 | return 0; |
86 | 0 | } |
87 | | |
88 | | // TODO(crbug.com/boringssl/607): Raise this limit. 512-bit RSA was factored |
89 | | // in 1999. |
90 | 0 | if (n_bits < 512) { |
91 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_KEY_SIZE_TOO_SMALL); |
92 | 0 | return 0; |
93 | 0 | } |
94 | | |
95 | | // RSA moduli must be positive and odd. In addition to being necessary for RSA |
96 | | // in general, we cannot setup Montgomery reduction with even moduli. |
97 | 0 | if (!BN_is_odd(rsa->n) || BN_is_negative(rsa->n)) { |
98 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_RSA_PARAMETERS); |
99 | 0 | return 0; |
100 | 0 | } |
101 | | |
102 | 0 | static const unsigned kMaxExponentBits = 33; |
103 | 0 | if (rsa->e != NULL) { |
104 | | // Reject e = 1, negative e, and even e. e must be odd to be relatively |
105 | | // prime with phi(n). |
106 | 0 | unsigned e_bits = BN_num_bits(rsa->e); |
107 | 0 | if (e_bits < 2 || BN_is_negative(rsa->e) || !BN_is_odd(rsa->e)) { |
108 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_E_VALUE); |
109 | 0 | return 0; |
110 | 0 | } |
111 | 0 | if (rsa->flags & RSA_FLAG_LARGE_PUBLIC_EXPONENT) { |
112 | | // The caller has requested disabling DoS protections. Still, e must be |
113 | | // less than n. |
114 | 0 | if (BN_ucmp(rsa->n, rsa->e) <= 0) { |
115 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_E_VALUE); |
116 | 0 | return 0; |
117 | 0 | } |
118 | 0 | } else { |
119 | | // Mitigate DoS attacks by limiting the exponent size. 33 bits was chosen |
120 | | // as the limit based on the recommendations in [1] and [2]. Windows |
121 | | // CryptoAPI doesn't support values larger than 32 bits [3], so it is |
122 | | // unlikely that exponents larger than 32 bits are being used for anything |
123 | | // Windows commonly does. |
124 | | // |
125 | | // [1] https://www.imperialviolet.org/2012/03/16/rsae.html |
126 | | // [2] https://www.imperialviolet.org/2012/03/17/rsados.html |
127 | | // [3] https://msdn.microsoft.com/en-us/library/aa387685(VS.85).aspx |
128 | 0 | if (e_bits > kMaxExponentBits) { |
129 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_E_VALUE); |
130 | 0 | return 0; |
131 | 0 | } |
132 | | |
133 | | // The upper bound on |e_bits| and lower bound on |n_bits| imply e is |
134 | | // bounded by n. |
135 | 0 | assert(BN_ucmp(rsa->n, rsa->e) > 0); |
136 | 0 | } |
137 | 0 | } else if (!(rsa->flags & RSA_FLAG_NO_PUBLIC_EXPONENT)) { |
138 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING); |
139 | 0 | return 0; |
140 | 0 | } |
141 | | |
142 | 0 | return 1; |
143 | 0 | } |
144 | | |
145 | 0 | static int ensure_fixed_copy(BIGNUM **out, const BIGNUM *in, int width) { |
146 | 0 | if (*out != NULL) { |
147 | 0 | return 1; |
148 | 0 | } |
149 | 0 | BIGNUM *copy = BN_dup(in); |
150 | 0 | if (copy == NULL || |
151 | 0 | !bn_resize_words(copy, width)) { |
152 | 0 | BN_free(copy); |
153 | 0 | return 0; |
154 | 0 | } |
155 | 0 | *out = copy; |
156 | 0 | bn_secret(copy); |
157 | |
|
158 | 0 | return 1; |
159 | 0 | } |
160 | | |
161 | | // freeze_private_key finishes initializing |rsa|'s private key components. |
162 | | // After this function has returned, |rsa| may not be changed. This is needed |
163 | | // because |RSA| is a public struct and, additionally, OpenSSL 1.1.0 opaquified |
164 | | // it wrong (see https://github.com/openssl/openssl/issues/5158). |
165 | 0 | static int freeze_private_key(RSA *rsa, BN_CTX *ctx) { |
166 | 0 | CRYPTO_MUTEX_lock_read(&rsa->lock); |
167 | 0 | int frozen = rsa->private_key_frozen; |
168 | 0 | CRYPTO_MUTEX_unlock_read(&rsa->lock); |
169 | 0 | if (frozen) { |
170 | 0 | return 1; |
171 | 0 | } |
172 | | |
173 | 0 | int ret = 0; |
174 | 0 | CRYPTO_MUTEX_lock_write(&rsa->lock); |
175 | 0 | if (rsa->private_key_frozen) { |
176 | 0 | ret = 1; |
177 | 0 | goto err; |
178 | 0 | } |
179 | | |
180 | | // Check the public components are within DoS bounds. |
181 | 0 | if (!rsa_check_public_key(rsa)) { |
182 | 0 | goto err; |
183 | 0 | } |
184 | | |
185 | | // Pre-compute various intermediate values, as well as copies of private |
186 | | // exponents with correct widths. Note that other threads may concurrently |
187 | | // read from |rsa->n|, |rsa->e|, etc., so any fixes must be in separate |
188 | | // copies. We use |mont_n->N|, |mont_p->N|, and |mont_q->N| as copies of |n|, |
189 | | // |p|, and |q| with the correct minimal widths. |
190 | | |
191 | 0 | if (rsa->mont_n == NULL) { |
192 | 0 | rsa->mont_n = BN_MONT_CTX_new_for_modulus(rsa->n, ctx); |
193 | 0 | if (rsa->mont_n == NULL) { |
194 | 0 | goto err; |
195 | 0 | } |
196 | 0 | } |
197 | 0 | const BIGNUM *n_fixed = &rsa->mont_n->N; |
198 | | |
199 | | // The only public upper-bound of |rsa->d| is the bit length of |rsa->n|. The |
200 | | // ASN.1 serialization of RSA private keys unfortunately leaks the byte length |
201 | | // of |rsa->d|, but normalize it so we only leak it once, rather than per |
202 | | // operation. |
203 | 0 | if (rsa->d != NULL && |
204 | 0 | !ensure_fixed_copy(&rsa->d_fixed, rsa->d, n_fixed->width)) { |
205 | 0 | goto err; |
206 | 0 | } |
207 | | |
208 | 0 | if (rsa->e != NULL && rsa->p != NULL && rsa->q != NULL) { |
209 | | // TODO: p and q are also CONSTTIME_SECRET but not yet marked as such |
210 | | // because the Montgomery code does things like test whether or not values |
211 | | // are zero. So the secret marking probably needs to happen inside that |
212 | | // code. |
213 | |
|
214 | 0 | if (rsa->mont_p == NULL) { |
215 | 0 | rsa->mont_p = BN_MONT_CTX_new_consttime(rsa->p, ctx); |
216 | 0 | if (rsa->mont_p == NULL) { |
217 | 0 | goto err; |
218 | 0 | } |
219 | 0 | } |
220 | 0 | const BIGNUM *p_fixed = &rsa->mont_p->N; |
221 | |
|
222 | 0 | if (rsa->mont_q == NULL) { |
223 | 0 | rsa->mont_q = BN_MONT_CTX_new_consttime(rsa->q, ctx); |
224 | 0 | if (rsa->mont_q == NULL) { |
225 | 0 | goto err; |
226 | 0 | } |
227 | 0 | } |
228 | 0 | const BIGNUM *q_fixed = &rsa->mont_q->N; |
229 | |
|
230 | 0 | if (rsa->dmp1 != NULL && rsa->dmq1 != NULL) { |
231 | | // Key generation relies on this function to compute |iqmp|. |
232 | 0 | if (rsa->iqmp == NULL) { |
233 | 0 | BIGNUM *iqmp = BN_new(); |
234 | 0 | if (iqmp == NULL || |
235 | 0 | !bn_mod_inverse_secret_prime(iqmp, rsa->q, rsa->p, ctx, |
236 | 0 | rsa->mont_p)) { |
237 | 0 | BN_free(iqmp); |
238 | 0 | goto err; |
239 | 0 | } |
240 | 0 | rsa->iqmp = iqmp; |
241 | 0 | } |
242 | | |
243 | | // CRT components are only publicly bounded by their corresponding |
244 | | // moduli's bit lengths. |
245 | 0 | if (!ensure_fixed_copy(&rsa->dmp1_fixed, rsa->dmp1, p_fixed->width) || |
246 | 0 | !ensure_fixed_copy(&rsa->dmq1_fixed, rsa->dmq1, q_fixed->width)) { |
247 | 0 | goto err; |
248 | 0 | } |
249 | | |
250 | | // Compute |iqmp_mont|, which is |iqmp| in Montgomery form and with the |
251 | | // correct bit width. |
252 | 0 | if (rsa->iqmp_mont == NULL) { |
253 | 0 | BIGNUM *iqmp_mont = BN_new(); |
254 | 0 | if (iqmp_mont == NULL || |
255 | 0 | !BN_to_montgomery(iqmp_mont, rsa->iqmp, rsa->mont_p, ctx)) { |
256 | 0 | BN_free(iqmp_mont); |
257 | 0 | goto err; |
258 | 0 | } |
259 | 0 | rsa->iqmp_mont = iqmp_mont; |
260 | 0 | bn_secret(rsa->iqmp_mont); |
261 | 0 | } |
262 | 0 | } |
263 | 0 | } |
264 | | |
265 | 0 | rsa->private_key_frozen = 1; |
266 | 0 | ret = 1; |
267 | |
|
268 | 0 | err: |
269 | 0 | CRYPTO_MUTEX_unlock_write(&rsa->lock); |
270 | 0 | return ret; |
271 | 0 | } |
272 | | |
273 | 0 | void rsa_invalidate_key(RSA *rsa) { |
274 | 0 | rsa->private_key_frozen = 0; |
275 | |
|
276 | 0 | BN_MONT_CTX_free(rsa->mont_n); |
277 | 0 | rsa->mont_n = NULL; |
278 | 0 | BN_MONT_CTX_free(rsa->mont_p); |
279 | 0 | rsa->mont_p = NULL; |
280 | 0 | BN_MONT_CTX_free(rsa->mont_q); |
281 | 0 | rsa->mont_q = NULL; |
282 | |
|
283 | 0 | BN_free(rsa->d_fixed); |
284 | 0 | rsa->d_fixed = NULL; |
285 | 0 | BN_free(rsa->dmp1_fixed); |
286 | 0 | rsa->dmp1_fixed = NULL; |
287 | 0 | BN_free(rsa->dmq1_fixed); |
288 | 0 | rsa->dmq1_fixed = NULL; |
289 | 0 | BN_free(rsa->iqmp_mont); |
290 | 0 | rsa->iqmp_mont = NULL; |
291 | |
|
292 | 0 | for (size_t i = 0; i < rsa->num_blindings; i++) { |
293 | 0 | BN_BLINDING_free(rsa->blindings[i]); |
294 | 0 | } |
295 | 0 | OPENSSL_free(rsa->blindings); |
296 | 0 | rsa->blindings = NULL; |
297 | 0 | rsa->num_blindings = 0; |
298 | 0 | OPENSSL_free(rsa->blindings_inuse); |
299 | 0 | rsa->blindings_inuse = NULL; |
300 | 0 | rsa->blinding_fork_generation = 0; |
301 | 0 | } |
302 | | |
303 | 0 | size_t rsa_default_size(const RSA *rsa) { |
304 | 0 | return BN_num_bytes(rsa->n); |
305 | 0 | } |
306 | | |
307 | | // MAX_BLINDINGS_PER_RSA defines the maximum number of cached BN_BLINDINGs per |
308 | | // RSA*. Then this limit is exceeded, BN_BLINDING objects will be created and |
309 | | // destroyed as needed. |
310 | | #if defined(OPENSSL_TSAN) |
311 | | // Smaller under TSAN so that the edge case can be hit with fewer threads. |
312 | | #define MAX_BLINDINGS_PER_RSA 2 |
313 | | #else |
314 | 0 | #define MAX_BLINDINGS_PER_RSA 1024 |
315 | | #endif |
316 | | |
317 | | // rsa_blinding_get returns a BN_BLINDING to use with |rsa|. It does this by |
318 | | // allocating one of the cached BN_BLINDING objects in |rsa->blindings|. If |
319 | | // none are free, the cache will be extended by a extra element and the new |
320 | | // BN_BLINDING is returned. |
321 | | // |
322 | | // On success, the index of the assigned BN_BLINDING is written to |
323 | | // |*index_used| and must be passed to |rsa_blinding_release| when finished. |
324 | | static BN_BLINDING *rsa_blinding_get(RSA *rsa, size_t *index_used, |
325 | 0 | BN_CTX *ctx) { |
326 | 0 | assert(ctx != NULL); |
327 | 0 | assert(rsa->mont_n != NULL); |
328 | | |
329 | 0 | BN_BLINDING *ret = NULL; |
330 | 0 | const uint64_t fork_generation = CRYPTO_get_fork_generation(); |
331 | 0 | CRYPTO_MUTEX_lock_write(&rsa->lock); |
332 | | |
333 | | // Wipe the blinding cache on |fork|. |
334 | 0 | if (rsa->blinding_fork_generation != fork_generation) { |
335 | 0 | for (size_t i = 0; i < rsa->num_blindings; i++) { |
336 | | // The inuse flag must be zero unless we were forked from a |
337 | | // multi-threaded process, in which case calling back into BoringSSL is |
338 | | // forbidden. |
339 | 0 | assert(rsa->blindings_inuse[i] == 0); |
340 | 0 | BN_BLINDING_invalidate(rsa->blindings[i]); |
341 | 0 | } |
342 | 0 | rsa->blinding_fork_generation = fork_generation; |
343 | 0 | } |
344 | | |
345 | 0 | uint8_t *const free_inuse_flag = |
346 | 0 | OPENSSL_memchr(rsa->blindings_inuse, 0, rsa->num_blindings); |
347 | 0 | if (free_inuse_flag != NULL) { |
348 | 0 | *free_inuse_flag = 1; |
349 | 0 | *index_used = free_inuse_flag - rsa->blindings_inuse; |
350 | 0 | ret = rsa->blindings[*index_used]; |
351 | 0 | goto out; |
352 | 0 | } |
353 | | |
354 | 0 | if (rsa->num_blindings >= MAX_BLINDINGS_PER_RSA) { |
355 | | // No |BN_BLINDING| is free and nor can the cache be extended. This index |
356 | | // value is magic and indicates to |rsa_blinding_release| that a |
357 | | // |BN_BLINDING| was not inserted into the array. |
358 | 0 | *index_used = MAX_BLINDINGS_PER_RSA; |
359 | 0 | ret = BN_BLINDING_new(); |
360 | 0 | goto out; |
361 | 0 | } |
362 | | |
363 | | // Double the length of the cache. |
364 | 0 | static_assert(MAX_BLINDINGS_PER_RSA < UINT_MAX / 2, |
365 | 0 | "MAX_BLINDINGS_PER_RSA too large"); |
366 | 0 | size_t new_num_blindings = rsa->num_blindings * 2; |
367 | 0 | if (new_num_blindings == 0) { |
368 | 0 | new_num_blindings = 1; |
369 | 0 | } |
370 | 0 | if (new_num_blindings > MAX_BLINDINGS_PER_RSA) { |
371 | 0 | new_num_blindings = MAX_BLINDINGS_PER_RSA; |
372 | 0 | } |
373 | 0 | assert(new_num_blindings > rsa->num_blindings); |
374 | | |
375 | 0 | BN_BLINDING **new_blindings = |
376 | 0 | OPENSSL_calloc(new_num_blindings, sizeof(BN_BLINDING *)); |
377 | 0 | uint8_t *new_blindings_inuse = OPENSSL_malloc(new_num_blindings); |
378 | 0 | if (new_blindings == NULL || new_blindings_inuse == NULL) { |
379 | 0 | goto err; |
380 | 0 | } |
381 | | |
382 | 0 | OPENSSL_memcpy(new_blindings, rsa->blindings, |
383 | 0 | sizeof(BN_BLINDING *) * rsa->num_blindings); |
384 | 0 | OPENSSL_memcpy(new_blindings_inuse, rsa->blindings_inuse, rsa->num_blindings); |
385 | |
|
386 | 0 | for (size_t i = rsa->num_blindings; i < new_num_blindings; i++) { |
387 | 0 | new_blindings[i] = BN_BLINDING_new(); |
388 | 0 | if (new_blindings[i] == NULL) { |
389 | 0 | for (size_t j = rsa->num_blindings; j < i; j++) { |
390 | 0 | BN_BLINDING_free(new_blindings[j]); |
391 | 0 | } |
392 | 0 | goto err; |
393 | 0 | } |
394 | 0 | } |
395 | 0 | memset(&new_blindings_inuse[rsa->num_blindings], 0, |
396 | 0 | new_num_blindings - rsa->num_blindings); |
397 | |
|
398 | 0 | new_blindings_inuse[rsa->num_blindings] = 1; |
399 | 0 | *index_used = rsa->num_blindings; |
400 | 0 | assert(*index_used != MAX_BLINDINGS_PER_RSA); |
401 | 0 | ret = new_blindings[rsa->num_blindings]; |
402 | |
|
403 | 0 | OPENSSL_free(rsa->blindings); |
404 | 0 | rsa->blindings = new_blindings; |
405 | 0 | OPENSSL_free(rsa->blindings_inuse); |
406 | 0 | rsa->blindings_inuse = new_blindings_inuse; |
407 | 0 | rsa->num_blindings = new_num_blindings; |
408 | |
|
409 | 0 | goto out; |
410 | | |
411 | 0 | err: |
412 | 0 | OPENSSL_free(new_blindings_inuse); |
413 | 0 | OPENSSL_free(new_blindings); |
414 | |
|
415 | 0 | out: |
416 | 0 | CRYPTO_MUTEX_unlock_write(&rsa->lock); |
417 | 0 | return ret; |
418 | 0 | } |
419 | | |
420 | | // rsa_blinding_release marks the cached BN_BLINDING at the given index as free |
421 | | // for other threads to use. |
422 | | static void rsa_blinding_release(RSA *rsa, BN_BLINDING *blinding, |
423 | 0 | size_t blinding_index) { |
424 | 0 | if (blinding_index == MAX_BLINDINGS_PER_RSA) { |
425 | | // This blinding wasn't cached. |
426 | 0 | BN_BLINDING_free(blinding); |
427 | 0 | return; |
428 | 0 | } |
429 | | |
430 | 0 | CRYPTO_MUTEX_lock_write(&rsa->lock); |
431 | 0 | rsa->blindings_inuse[blinding_index] = 0; |
432 | 0 | CRYPTO_MUTEX_unlock_write(&rsa->lock); |
433 | 0 | } |
434 | | |
435 | | // signing |
436 | | int rsa_default_sign_raw(RSA *rsa, size_t *out_len, uint8_t *out, |
437 | | size_t max_out, const uint8_t *in, size_t in_len, |
438 | 0 | int padding) { |
439 | 0 | const unsigned rsa_size = RSA_size(rsa); |
440 | 0 | uint8_t *buf = NULL; |
441 | 0 | int i, ret = 0; |
442 | |
|
443 | 0 | if (max_out < rsa_size) { |
444 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_OUTPUT_BUFFER_TOO_SMALL); |
445 | 0 | return 0; |
446 | 0 | } |
447 | | |
448 | 0 | buf = OPENSSL_malloc(rsa_size); |
449 | 0 | if (buf == NULL) { |
450 | 0 | goto err; |
451 | 0 | } |
452 | | |
453 | 0 | switch (padding) { |
454 | 0 | case RSA_PKCS1_PADDING: |
455 | 0 | i = RSA_padding_add_PKCS1_type_1(buf, rsa_size, in, in_len); |
456 | 0 | break; |
457 | 0 | case RSA_NO_PADDING: |
458 | 0 | i = RSA_padding_add_none(buf, rsa_size, in, in_len); |
459 | 0 | break; |
460 | 0 | default: |
461 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
462 | 0 | goto err; |
463 | 0 | } |
464 | | |
465 | 0 | if (i <= 0) { |
466 | 0 | goto err; |
467 | 0 | } |
468 | | |
469 | 0 | if (!rsa_private_transform_no_self_test(rsa, out, buf, rsa_size)) { |
470 | 0 | goto err; |
471 | 0 | } |
472 | | |
473 | 0 | CONSTTIME_DECLASSIFY(out, rsa_size); |
474 | 0 | *out_len = rsa_size; |
475 | 0 | ret = 1; |
476 | |
|
477 | 0 | err: |
478 | 0 | OPENSSL_free(buf); |
479 | |
|
480 | 0 | return ret; |
481 | 0 | } |
482 | | |
483 | | |
484 | | static int mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx); |
485 | | |
486 | | int rsa_verify_raw_no_self_test(RSA *rsa, size_t *out_len, uint8_t *out, |
487 | | size_t max_out, const uint8_t *in, |
488 | 0 | size_t in_len, int padding) { |
489 | 0 | if (rsa->n == NULL || rsa->e == NULL) { |
490 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING); |
491 | 0 | return 0; |
492 | 0 | } |
493 | | |
494 | 0 | if (!rsa_check_public_key(rsa)) { |
495 | 0 | return 0; |
496 | 0 | } |
497 | | |
498 | 0 | const unsigned rsa_size = RSA_size(rsa); |
499 | 0 | BIGNUM *f, *result; |
500 | |
|
501 | 0 | if (max_out < rsa_size) { |
502 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_OUTPUT_BUFFER_TOO_SMALL); |
503 | 0 | return 0; |
504 | 0 | } |
505 | | |
506 | 0 | if (in_len != rsa_size) { |
507 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_LEN_NOT_EQUAL_TO_MOD_LEN); |
508 | 0 | return 0; |
509 | 0 | } |
510 | | |
511 | 0 | BN_CTX *ctx = BN_CTX_new(); |
512 | 0 | if (ctx == NULL) { |
513 | 0 | return 0; |
514 | 0 | } |
515 | | |
516 | 0 | int ret = 0; |
517 | 0 | uint8_t *buf = NULL; |
518 | |
|
519 | 0 | BN_CTX_start(ctx); |
520 | 0 | f = BN_CTX_get(ctx); |
521 | 0 | result = BN_CTX_get(ctx); |
522 | 0 | if (f == NULL || result == NULL) { |
523 | 0 | goto err; |
524 | 0 | } |
525 | | |
526 | 0 | if (padding == RSA_NO_PADDING) { |
527 | 0 | buf = out; |
528 | 0 | } else { |
529 | | // Allocate a temporary buffer to hold the padded plaintext. |
530 | 0 | buf = OPENSSL_malloc(rsa_size); |
531 | 0 | if (buf == NULL) { |
532 | 0 | goto err; |
533 | 0 | } |
534 | 0 | } |
535 | | |
536 | 0 | if (BN_bin2bn(in, in_len, f) == NULL) { |
537 | 0 | goto err; |
538 | 0 | } |
539 | | |
540 | 0 | if (BN_ucmp(f, rsa->n) >= 0) { |
541 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
542 | 0 | goto err; |
543 | 0 | } |
544 | | |
545 | 0 | if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx) || |
546 | 0 | !BN_mod_exp_mont(result, f, rsa->e, &rsa->mont_n->N, ctx, rsa->mont_n)) { |
547 | 0 | goto err; |
548 | 0 | } |
549 | | |
550 | 0 | if (!BN_bn2bin_padded(buf, rsa_size, result)) { |
551 | 0 | OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
552 | 0 | goto err; |
553 | 0 | } |
554 | | |
555 | 0 | switch (padding) { |
556 | 0 | case RSA_PKCS1_PADDING: |
557 | 0 | ret = |
558 | 0 | RSA_padding_check_PKCS1_type_1(out, out_len, rsa_size, buf, rsa_size); |
559 | 0 | break; |
560 | 0 | case RSA_NO_PADDING: |
561 | 0 | ret = 1; |
562 | 0 | *out_len = rsa_size; |
563 | 0 | break; |
564 | 0 | default: |
565 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
566 | 0 | goto err; |
567 | 0 | } |
568 | | |
569 | 0 | if (!ret) { |
570 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_PADDING_CHECK_FAILED); |
571 | 0 | goto err; |
572 | 0 | } |
573 | | |
574 | 0 | err: |
575 | 0 | BN_CTX_end(ctx); |
576 | 0 | BN_CTX_free(ctx); |
577 | 0 | if (buf != out) { |
578 | 0 | OPENSSL_free(buf); |
579 | 0 | } |
580 | 0 | return ret; |
581 | 0 | } |
582 | | |
583 | | int RSA_verify_raw(RSA *rsa, size_t *out_len, uint8_t *out, |
584 | | size_t max_out, const uint8_t *in, |
585 | 0 | size_t in_len, int padding) { |
586 | 0 | boringssl_ensure_rsa_self_test(); |
587 | 0 | return rsa_verify_raw_no_self_test(rsa, out_len, out, max_out, in, in_len, |
588 | 0 | padding); |
589 | 0 | } |
590 | | |
591 | | int rsa_default_private_transform(RSA *rsa, uint8_t *out, const uint8_t *in, |
592 | 0 | size_t len) { |
593 | 0 | if (rsa->n == NULL || rsa->d == NULL) { |
594 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING); |
595 | 0 | return 0; |
596 | 0 | } |
597 | | |
598 | 0 | BIGNUM *f, *result; |
599 | 0 | BN_CTX *ctx = NULL; |
600 | 0 | size_t blinding_index = 0; |
601 | 0 | BN_BLINDING *blinding = NULL; |
602 | 0 | int ret = 0; |
603 | |
|
604 | 0 | ctx = BN_CTX_new(); |
605 | 0 | if (ctx == NULL) { |
606 | 0 | goto err; |
607 | 0 | } |
608 | 0 | BN_CTX_start(ctx); |
609 | 0 | f = BN_CTX_get(ctx); |
610 | 0 | result = BN_CTX_get(ctx); |
611 | |
|
612 | 0 | if (f == NULL || result == NULL) { |
613 | 0 | goto err; |
614 | 0 | } |
615 | | |
616 | | // The caller should have ensured this. |
617 | 0 | assert(len == BN_num_bytes(rsa->n)); |
618 | 0 | if (BN_bin2bn(in, len, f) == NULL) { |
619 | 0 | goto err; |
620 | 0 | } |
621 | | |
622 | | // The input to the RSA private transform may be secret, but padding is |
623 | | // expected to construct a value within range, so we can leak this comparison. |
624 | 0 | if (constant_time_declassify_int(BN_ucmp(f, rsa->n) >= 0)) { |
625 | | // Usually the padding functions would catch this. |
626 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
627 | 0 | goto err; |
628 | 0 | } |
629 | | |
630 | 0 | if (!freeze_private_key(rsa, ctx)) { |
631 | 0 | OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
632 | 0 | goto err; |
633 | 0 | } |
634 | | |
635 | 0 | const int do_blinding = |
636 | 0 | (rsa->flags & (RSA_FLAG_NO_BLINDING | RSA_FLAG_NO_PUBLIC_EXPONENT)) == 0; |
637 | |
|
638 | 0 | if (rsa->e == NULL && do_blinding) { |
639 | | // We cannot do blinding or verification without |e|, and continuing without |
640 | | // those countermeasures is dangerous. However, the Java/Android RSA API |
641 | | // requires support for keys where only |d| and |n| (and not |e|) are known. |
642 | | // The callers that require that bad behavior must set |
643 | | // |RSA_FLAG_NO_BLINDING| or use |RSA_new_private_key_no_e|. |
644 | | // |
645 | | // TODO(davidben): Update this comment when Conscrypt is updated to use |
646 | | // |RSA_new_private_key_no_e|. |
647 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_NO_PUBLIC_EXPONENT); |
648 | 0 | goto err; |
649 | 0 | } |
650 | | |
651 | 0 | if (do_blinding) { |
652 | 0 | blinding = rsa_blinding_get(rsa, &blinding_index, ctx); |
653 | 0 | if (blinding == NULL) { |
654 | 0 | OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
655 | 0 | goto err; |
656 | 0 | } |
657 | 0 | if (!BN_BLINDING_convert(f, blinding, rsa->e, rsa->mont_n, ctx)) { |
658 | 0 | goto err; |
659 | 0 | } |
660 | 0 | } |
661 | | |
662 | 0 | if (rsa->p != NULL && rsa->q != NULL && rsa->e != NULL && rsa->dmp1 != NULL && |
663 | 0 | rsa->dmq1 != NULL && rsa->iqmp != NULL && |
664 | | // Require that we can reduce |f| by |rsa->p| and |rsa->q| in constant |
665 | | // time, which requires primes be the same size, rounded to the Montgomery |
666 | | // coefficient. (See |mod_montgomery|.) This is not required by RFC 8017, |
667 | | // but it is true for keys generated by us and all common implementations. |
668 | 0 | bn_less_than_montgomery_R(rsa->q, rsa->mont_p) && |
669 | 0 | bn_less_than_montgomery_R(rsa->p, rsa->mont_q)) { |
670 | 0 | if (!mod_exp(result, f, rsa, ctx)) { |
671 | 0 | goto err; |
672 | 0 | } |
673 | 0 | } else if (!BN_mod_exp_mont_consttime(result, f, rsa->d_fixed, rsa->n, ctx, |
674 | 0 | rsa->mont_n)) { |
675 | 0 | goto err; |
676 | 0 | } |
677 | | |
678 | | // Verify the result to protect against fault attacks as described in the |
679 | | // 1997 paper "On the Importance of Checking Cryptographic Protocols for |
680 | | // Faults" by Dan Boneh, Richard A. DeMillo, and Richard J. Lipton. Some |
681 | | // implementations do this only when the CRT is used, but we do it in all |
682 | | // cases. Section 6 of the aforementioned paper describes an attack that |
683 | | // works when the CRT isn't used. That attack is much less likely to succeed |
684 | | // than the CRT attack, but there have likely been improvements since 1997. |
685 | | // |
686 | | // This check is cheap assuming |e| is small, which we require in |
687 | | // |rsa_check_public_key|. |
688 | 0 | if (rsa->e != NULL) { |
689 | 0 | BIGNUM *vrfy = BN_CTX_get(ctx); |
690 | 0 | if (vrfy == NULL || |
691 | 0 | !BN_mod_exp_mont(vrfy, result, rsa->e, rsa->n, ctx, rsa->mont_n) || |
692 | 0 | !constant_time_declassify_int(BN_equal_consttime(vrfy, f))) { |
693 | 0 | OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
694 | 0 | goto err; |
695 | 0 | } |
696 | 0 | } |
697 | | |
698 | 0 | if (do_blinding && |
699 | 0 | !BN_BLINDING_invert(result, blinding, rsa->mont_n, ctx)) { |
700 | 0 | goto err; |
701 | 0 | } |
702 | | |
703 | | // The computation should have left |result| as a maximally-wide number, so |
704 | | // that it and serializing does not leak information about the magnitude of |
705 | | // the result. |
706 | | // |
707 | | // See Falko Strenzke, "Manger's Attack revisited", ICICS 2010. |
708 | 0 | assert(result->width == rsa->mont_n->N.width); |
709 | 0 | bn_assert_fits_in_bytes(result, len); |
710 | 0 | if (!BN_bn2bin_padded(out, len, result)) { |
711 | 0 | OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
712 | 0 | goto err; |
713 | 0 | } |
714 | | |
715 | 0 | ret = 1; |
716 | |
|
717 | 0 | err: |
718 | 0 | if (ctx != NULL) { |
719 | 0 | BN_CTX_end(ctx); |
720 | 0 | BN_CTX_free(ctx); |
721 | 0 | } |
722 | 0 | if (blinding != NULL) { |
723 | 0 | rsa_blinding_release(rsa, blinding, blinding_index); |
724 | 0 | } |
725 | |
|
726 | 0 | return ret; |
727 | 0 | } |
728 | | |
729 | | // mod_montgomery sets |r| to |I| mod |p|. |I| must already be fully reduced |
730 | | // modulo |p| times |q|. It returns one on success and zero on error. |
731 | | static int mod_montgomery(BIGNUM *r, const BIGNUM *I, const BIGNUM *p, |
732 | | const BN_MONT_CTX *mont_p, const BIGNUM *q, |
733 | 0 | BN_CTX *ctx) { |
734 | | // Reducing in constant-time with Montgomery reduction requires I <= p * R. We |
735 | | // have I < p * q, so this follows if q < R. The caller should have checked |
736 | | // this already. |
737 | 0 | if (!bn_less_than_montgomery_R(q, mont_p)) { |
738 | 0 | OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
739 | 0 | return 0; |
740 | 0 | } |
741 | | |
742 | 0 | if (// Reduce mod p with Montgomery reduction. This computes I * R^-1 mod p. |
743 | 0 | !BN_from_montgomery(r, I, mont_p, ctx) || |
744 | | // Multiply by R^2 and do another Montgomery reduction to compute |
745 | | // I * R^-1 * R^2 * R^-1 = I mod p. |
746 | 0 | !BN_to_montgomery(r, r, mont_p, ctx)) { |
747 | 0 | return 0; |
748 | 0 | } |
749 | | |
750 | | // By precomputing R^3 mod p (normally |BN_MONT_CTX| only uses R^2 mod p) and |
751 | | // adjusting the API for |BN_mod_exp_mont_consttime|, we could instead compute |
752 | | // I * R mod p here and save a reduction per prime. But this would require |
753 | | // changing the RSAZ code and may not be worth it. Note that the RSAZ code |
754 | | // uses a different radix, so it uses R' = 2^1044. There we'd actually want |
755 | | // R^2 * R', and would futher benefit from a precomputed R'^2. It currently |
756 | | // converts |mont_p->RR| to R'^2. |
757 | 0 | return 1; |
758 | 0 | } |
759 | | |
760 | 0 | static int mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) { |
761 | 0 | assert(ctx != NULL); |
762 | | |
763 | 0 | assert(rsa->n != NULL); |
764 | 0 | assert(rsa->e != NULL); |
765 | 0 | assert(rsa->d != NULL); |
766 | 0 | assert(rsa->p != NULL); |
767 | 0 | assert(rsa->q != NULL); |
768 | 0 | assert(rsa->dmp1 != NULL); |
769 | 0 | assert(rsa->dmq1 != NULL); |
770 | 0 | assert(rsa->iqmp != NULL); |
771 | | |
772 | 0 | BIGNUM *r1, *m1; |
773 | 0 | int ret = 0; |
774 | |
|
775 | 0 | BN_CTX_start(ctx); |
776 | 0 | r1 = BN_CTX_get(ctx); |
777 | 0 | m1 = BN_CTX_get(ctx); |
778 | 0 | if (r1 == NULL || |
779 | 0 | m1 == NULL) { |
780 | 0 | goto err; |
781 | 0 | } |
782 | | |
783 | 0 | if (!freeze_private_key(rsa, ctx)) { |
784 | 0 | goto err; |
785 | 0 | } |
786 | | |
787 | | // Use the minimal-width versions of |n|, |p|, and |q|. Either works, but if |
788 | | // someone gives us non-minimal values, these will be slightly more efficient |
789 | | // on the non-Montgomery operations. |
790 | 0 | const BIGNUM *n = &rsa->mont_n->N; |
791 | 0 | const BIGNUM *p = &rsa->mont_p->N; |
792 | 0 | const BIGNUM *q = &rsa->mont_q->N; |
793 | | |
794 | | // This is a pre-condition for |mod_montgomery|. It was already checked by the |
795 | | // caller. |
796 | 0 | declassify_assert(BN_ucmp(I, n) < 0); |
797 | | |
798 | 0 | if (// |m1| is the result modulo |q|. |
799 | 0 | !mod_montgomery(r1, I, q, rsa->mont_q, p, ctx) || |
800 | 0 | !BN_mod_exp_mont_consttime(m1, r1, rsa->dmq1_fixed, q, ctx, |
801 | 0 | rsa->mont_q) || |
802 | | // |r0| is the result modulo |p|. |
803 | 0 | !mod_montgomery(r1, I, p, rsa->mont_p, q, ctx) || |
804 | 0 | !BN_mod_exp_mont_consttime(r0, r1, rsa->dmp1_fixed, p, ctx, |
805 | 0 | rsa->mont_p) || |
806 | | // Compute r0 = r0 - m1 mod p. |m1| is reduced mod |q|, not |p|, so we |
807 | | // just run |mod_montgomery| again for simplicity. This could be more |
808 | | // efficient with more cases: if |p > q|, |m1| is already reduced. If |
809 | | // |p < q| but they have the same bit width, |bn_reduce_once| suffices. |
810 | | // However, compared to over 2048 Montgomery multiplications above, this |
811 | | // difference is not measurable. |
812 | 0 | !mod_montgomery(r1, m1, p, rsa->mont_p, q, ctx) || |
813 | 0 | !bn_mod_sub_consttime(r0, r0, r1, p, ctx) || |
814 | | // r0 = r0 * iqmp mod p. We use Montgomery multiplication to compute this |
815 | | // in constant time. |iqmp_mont| is in Montgomery form and r0 is not, so |
816 | | // the result is taken out of Montgomery form. |
817 | 0 | !BN_mod_mul_montgomery(r0, r0, rsa->iqmp_mont, rsa->mont_p, ctx) || |
818 | | // r0 = r0 * q + m1 gives the final result. Reducing modulo q gives m1, so |
819 | | // it is correct mod p. Reducing modulo p gives (r0-m1)*iqmp*q + m1 = r0, |
820 | | // so it is correct mod q. Finally, the result is bounded by [m1, n + m1), |
821 | | // and the result is at least |m1|, so this must be the unique answer in |
822 | | // [0, n). |
823 | 0 | !bn_mul_consttime(r0, r0, q, ctx) || // |
824 | 0 | !bn_uadd_consttime(r0, r0, m1)) { |
825 | 0 | goto err; |
826 | 0 | } |
827 | | |
828 | | // The result should be bounded by |n|, but fixed-width operations may |
829 | | // bound the width slightly higher, so fix it. This trips constant-time checks |
830 | | // because a naive data flow analysis does not realize the excess words are |
831 | | // publicly zero. |
832 | 0 | declassify_assert(BN_cmp(r0, n) < 0); |
833 | 0 | bn_assert_fits_in_bytes(r0, BN_num_bytes(n)); |
834 | 0 | if (!bn_resize_words(r0, n->width)) { |
835 | 0 | goto err; |
836 | 0 | } |
837 | | |
838 | 0 | ret = 1; |
839 | |
|
840 | 0 | err: |
841 | 0 | BN_CTX_end(ctx); |
842 | 0 | return ret; |
843 | 0 | } |
844 | | |
845 | 0 | static int ensure_bignum(BIGNUM **out) { |
846 | 0 | if (*out == NULL) { |
847 | 0 | *out = BN_new(); |
848 | 0 | } |
849 | 0 | return *out != NULL; |
850 | 0 | } |
851 | | |
852 | | // kBoringSSLRSASqrtTwo is the BIGNUM representation of ⌊2²⁰⁴⁷×√2⌋. This is |
853 | | // chosen to give enough precision for 4096-bit RSA, the largest key size FIPS |
854 | | // specifies. Key sizes beyond this will round up. |
855 | | // |
856 | | // To calculate, use the following Haskell code: |
857 | | // |
858 | | // import Text.Printf (printf) |
859 | | // import Data.List (intercalate) |
860 | | // |
861 | | // pow2 = 4095 |
862 | | // target = 2^pow2 |
863 | | // |
864 | | // f x = x*x - (toRational target) |
865 | | // |
866 | | // fprime x = 2*x |
867 | | // |
868 | | // newtonIteration x = x - (f x) / (fprime x) |
869 | | // |
870 | | // converge x = |
871 | | // let n = floor x in |
872 | | // if n*n - target < 0 && (n+1)*(n+1) - target > 0 |
873 | | // then n |
874 | | // else converge (newtonIteration x) |
875 | | // |
876 | | // divrem bits x = (x `div` (2^bits), x `rem` (2^bits)) |
877 | | // |
878 | | // bnWords :: Integer -> [Integer] |
879 | | // bnWords x = |
880 | | // if x == 0 |
881 | | // then [] |
882 | | // else let (high, low) = divrem 64 x in low : bnWords high |
883 | | // |
884 | | // showWord x = let (high, low) = divrem 32 x in printf "TOBN(0x%08x, 0x%08x)" high low |
885 | | // |
886 | | // output :: String |
887 | | // output = intercalate ", " $ map showWord $ bnWords $ converge (2 ^ (pow2 `div` 2)) |
888 | | // |
889 | | // To verify this number, check that n² < 2⁴⁰⁹⁵ < (n+1)², where n is value |
890 | | // represented here. Note the components are listed in little-endian order. Here |
891 | | // is some sample Python code to check: |
892 | | // |
893 | | // >>> TOBN = lambda a, b: a << 32 | b |
894 | | // >>> l = [ <paste the contents of kSqrtTwo> ] |
895 | | // >>> n = sum(a * 2**(64*i) for i, a in enumerate(l)) |
896 | | // >>> n**2 < 2**4095 < (n+1)**2 |
897 | | // True |
898 | | const BN_ULONG kBoringSSLRSASqrtTwo[] = { |
899 | | TOBN(0x4d7c60a5, 0xe633e3e1), TOBN(0x5fcf8f7b, 0xca3ea33b), |
900 | | TOBN(0xc246785e, 0x92957023), TOBN(0xf9acce41, 0x797f2805), |
901 | | TOBN(0xfdfe170f, 0xd3b1f780), TOBN(0xd24f4a76, 0x3facb882), |
902 | | TOBN(0x18838a2e, 0xaff5f3b2), TOBN(0xc1fcbdde, 0xa2f7dc33), |
903 | | TOBN(0xdea06241, 0xf7aa81c2), TOBN(0xf6a1be3f, 0xca221307), |
904 | | TOBN(0x332a5e9f, 0x7bda1ebf), TOBN(0x0104dc01, 0xfe32352f), |
905 | | TOBN(0xb8cf341b, 0x6f8236c7), TOBN(0x4264dabc, 0xd528b651), |
906 | | TOBN(0xf4d3a02c, 0xebc93e0c), TOBN(0x81394ab6, 0xd8fd0efd), |
907 | | TOBN(0xeaa4a089, 0x9040ca4a), TOBN(0xf52f120f, 0x836e582e), |
908 | | TOBN(0xcb2a6343, 0x31f3c84d), TOBN(0xc6d5a8a3, 0x8bb7e9dc), |
909 | | TOBN(0x460abc72, 0x2f7c4e33), TOBN(0xcab1bc91, 0x1688458a), |
910 | | TOBN(0x53059c60, 0x11bc337b), TOBN(0xd2202e87, 0x42af1f4e), |
911 | | TOBN(0x78048736, 0x3dfa2768), TOBN(0x0f74a85e, 0x439c7b4a), |
912 | | TOBN(0xa8b1fe6f, 0xdc83db39), TOBN(0x4afc8304, 0x3ab8a2c3), |
913 | | TOBN(0xed17ac85, 0x83339915), TOBN(0x1d6f60ba, 0x893ba84c), |
914 | | TOBN(0x597d89b3, 0x754abe9f), TOBN(0xb504f333, 0xf9de6484), |
915 | | }; |
916 | | const size_t kBoringSSLRSASqrtTwoLen = OPENSSL_ARRAY_SIZE(kBoringSSLRSASqrtTwo); |
917 | | |
918 | | // generate_prime sets |out| to a prime with length |bits| such that |out|-1 is |
919 | | // relatively prime to |e|. If |p| is non-NULL, |out| will also not be close to |
920 | | // |p|. |sqrt2| must be ⌊2^(bits-1)×√2⌋ (or a slightly overestimate for large |
921 | | // sizes), and |pow2_bits_100| must be 2^(bits-100). |
922 | | // |
923 | | // This function fails with probability around 2^-21. |
924 | | static int generate_prime(BIGNUM *out, int bits, const BIGNUM *e, |
925 | | const BIGNUM *p, const BIGNUM *sqrt2, |
926 | | const BIGNUM *pow2_bits_100, BN_CTX *ctx, |
927 | 0 | BN_GENCB *cb) { |
928 | 0 | if (bits < 128 || (bits % BN_BITS2) != 0) { |
929 | 0 | OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
930 | 0 | return 0; |
931 | 0 | } |
932 | 0 | assert(BN_is_pow2(pow2_bits_100)); |
933 | 0 | assert(BN_is_bit_set(pow2_bits_100, bits - 100)); |
934 | | |
935 | | // See FIPS 186-4 appendix B.3.3, steps 4 and 5. Note |bits| here is nlen/2. |
936 | | |
937 | | // Use the limit from steps 4.7 and 5.8 for most values of |e|. When |e| is 3, |
938 | | // the 186-4 limit is too low, so we use a higher one. Note this case is not |
939 | | // reachable from |RSA_generate_key_fips|. |
940 | | // |
941 | | // |limit| determines the failure probability. We must find a prime that is |
942 | | // not 1 mod |e|. By the prime number theorem, we'll find one with probability |
943 | | // p = (e-1)/e * 2/(ln(2)*bits). Note the second term is doubled because we |
944 | | // discard even numbers. |
945 | | // |
946 | | // The failure probability is thus (1-p)^limit. To convert that to a power of |
947 | | // two, we take logs. -log_2((1-p)^limit) = -limit * ln(1-p) / ln(2). |
948 | | // |
949 | | // >>> def f(bits, e, limit): |
950 | | // ... p = (e-1.0)/e * 2.0/(math.log(2)*bits) |
951 | | // ... return -limit * math.log(1 - p) / math.log(2) |
952 | | // ... |
953 | | // >>> f(1024, 65537, 5*1024) |
954 | | // 20.842750558272634 |
955 | | // >>> f(1536, 65537, 5*1536) |
956 | | // 20.83294549602474 |
957 | | // >>> f(2048, 65537, 5*2048) |
958 | | // 20.828047576234948 |
959 | | // >>> f(1024, 3, 8*1024) |
960 | | // 22.222147925962307 |
961 | | // >>> f(1536, 3, 8*1536) |
962 | | // 22.21518251065506 |
963 | | // >>> f(2048, 3, 8*2048) |
964 | | // 22.211701985875937 |
965 | 0 | if (bits >= INT_MAX/32) { |
966 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_MODULUS_TOO_LARGE); |
967 | 0 | return 0; |
968 | 0 | } |
969 | 0 | int limit = BN_is_word(e, 3) ? bits * 8 : bits * 5; |
970 | |
|
971 | 0 | int ret = 0, tries = 0, rand_tries = 0; |
972 | 0 | BN_CTX_start(ctx); |
973 | 0 | BIGNUM *tmp = BN_CTX_get(ctx); |
974 | 0 | if (tmp == NULL) { |
975 | 0 | goto err; |
976 | 0 | } |
977 | | |
978 | 0 | for (;;) { |
979 | | // Generate a random number of length |bits| where the bottom bit is set |
980 | | // (steps 4.2, 4.3, 5.2 and 5.3) and the top bit is set (implied by the |
981 | | // bound checked below in steps 4.4 and 5.5). |
982 | 0 | if (!BN_rand(out, bits, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ODD) || |
983 | 0 | !BN_GENCB_call(cb, BN_GENCB_GENERATED, rand_tries++)) { |
984 | 0 | goto err; |
985 | 0 | } |
986 | | |
987 | 0 | if (p != NULL) { |
988 | | // If |p| and |out| are too close, try again (step 5.4). |
989 | 0 | if (!bn_abs_sub_consttime(tmp, out, p, ctx)) { |
990 | 0 | goto err; |
991 | 0 | } |
992 | 0 | if (BN_cmp(tmp, pow2_bits_100) <= 0) { |
993 | 0 | continue; |
994 | 0 | } |
995 | 0 | } |
996 | | |
997 | | // If out < 2^(bits-1)×√2, try again (steps 4.4 and 5.5). This is equivalent |
998 | | // to out <= ⌊2^(bits-1)×√2⌋, or out <= sqrt2 for FIPS key sizes. |
999 | | // |
1000 | | // For larger keys, the comparison is approximate, leaning towards |
1001 | | // retrying. That is, we reject a negligible fraction of primes that are |
1002 | | // within the FIPS bound, but we will never accept a prime outside the |
1003 | | // bound, ensuring the resulting RSA key is the right size. |
1004 | | // |
1005 | | // Values over the threshold are discarded, so it is safe to leak this |
1006 | | // comparison. |
1007 | 0 | if (constant_time_declassify_int(BN_cmp(out, sqrt2) <= 0)) { |
1008 | 0 | continue; |
1009 | 0 | } |
1010 | | |
1011 | | // RSA key generation's bottleneck is discarding composites. If it fails |
1012 | | // trial division, do not bother computing a GCD or performing Miller-Rabin. |
1013 | 0 | if (!bn_odd_number_is_obviously_composite(out)) { |
1014 | | // Check gcd(out-1, e) is one (steps 4.5 and 5.6). Leaking the final |
1015 | | // result of this comparison is safe because, if not relatively prime, the |
1016 | | // value will be discarded. |
1017 | 0 | int relatively_prime; |
1018 | 0 | if (!bn_usub_consttime(tmp, out, BN_value_one()) || |
1019 | 0 | !bn_is_relatively_prime(&relatively_prime, tmp, e, ctx)) { |
1020 | 0 | goto err; |
1021 | 0 | } |
1022 | 0 | if (constant_time_declassify_int(relatively_prime)) { |
1023 | | // Test |out| for primality (steps 4.5.1 and 5.6.1). |
1024 | 0 | int is_probable_prime; |
1025 | 0 | if (!BN_primality_test(&is_probable_prime, out, |
1026 | 0 | BN_prime_checks_for_generation, ctx, 0, cb)) { |
1027 | 0 | goto err; |
1028 | 0 | } |
1029 | 0 | if (is_probable_prime) { |
1030 | 0 | ret = 1; |
1031 | 0 | goto err; |
1032 | 0 | } |
1033 | 0 | } |
1034 | 0 | } |
1035 | | |
1036 | | // If we've tried too many times to find a prime, abort (steps 4.7 and |
1037 | | // 5.8). |
1038 | 0 | tries++; |
1039 | 0 | if (tries >= limit) { |
1040 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_TOO_MANY_ITERATIONS); |
1041 | 0 | goto err; |
1042 | 0 | } |
1043 | 0 | if (!BN_GENCB_call(cb, 2, tries)) { |
1044 | 0 | goto err; |
1045 | 0 | } |
1046 | 0 | } |
1047 | | |
1048 | 0 | err: |
1049 | 0 | BN_CTX_end(ctx); |
1050 | 0 | return ret; |
1051 | 0 | } |
1052 | | |
1053 | | // rsa_generate_key_impl generates an RSA key using a generalized version of |
1054 | | // FIPS 186-4 appendix B.3. |RSA_generate_key_fips| performs additional checks |
1055 | | // for FIPS-compliant key generation. |
1056 | | // |
1057 | | // This function returns one on success and zero on failure. It has a failure |
1058 | | // probability of about 2^-20. |
1059 | | static int rsa_generate_key_impl(RSA *rsa, int bits, const BIGNUM *e_value, |
1060 | 0 | BN_GENCB *cb) { |
1061 | | // See FIPS 186-4 appendix B.3. This function implements a generalized version |
1062 | | // of the FIPS algorithm. |RSA_generate_key_fips| performs additional checks |
1063 | | // for FIPS-compliant key generation. |
1064 | | |
1065 | | // Always generate RSA keys which are a multiple of 128 bits. Round |bits| |
1066 | | // down as needed. |
1067 | 0 | bits &= ~127; |
1068 | | |
1069 | | // Reject excessively small keys. |
1070 | 0 | if (bits < 256) { |
1071 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_KEY_SIZE_TOO_SMALL); |
1072 | 0 | return 0; |
1073 | 0 | } |
1074 | | |
1075 | | // Reject excessively large public exponents. Windows CryptoAPI and Go don't |
1076 | | // support values larger than 32 bits, so match their limits for generating |
1077 | | // keys. (|rsa_check_public_key| uses a slightly more conservative value, but |
1078 | | // we don't need to support generating such keys.) |
1079 | | // https://github.com/golang/go/issues/3161 |
1080 | | // https://msdn.microsoft.com/en-us/library/aa387685(VS.85).aspx |
1081 | 0 | if (BN_num_bits(e_value) > 32) { |
1082 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_E_VALUE); |
1083 | 0 | return 0; |
1084 | 0 | } |
1085 | | |
1086 | 0 | int ret = 0; |
1087 | 0 | int prime_bits = bits / 2; |
1088 | 0 | BN_CTX *ctx = BN_CTX_new(); |
1089 | 0 | if (ctx == NULL) { |
1090 | 0 | goto bn_err; |
1091 | 0 | } |
1092 | 0 | BN_CTX_start(ctx); |
1093 | 0 | BIGNUM *totient = BN_CTX_get(ctx); |
1094 | 0 | BIGNUM *pm1 = BN_CTX_get(ctx); |
1095 | 0 | BIGNUM *qm1 = BN_CTX_get(ctx); |
1096 | 0 | BIGNUM *sqrt2 = BN_CTX_get(ctx); |
1097 | 0 | BIGNUM *pow2_prime_bits_100 = BN_CTX_get(ctx); |
1098 | 0 | BIGNUM *pow2_prime_bits = BN_CTX_get(ctx); |
1099 | 0 | if (totient == NULL || pm1 == NULL || qm1 == NULL || sqrt2 == NULL || |
1100 | 0 | pow2_prime_bits_100 == NULL || pow2_prime_bits == NULL || |
1101 | 0 | !BN_set_bit(pow2_prime_bits_100, prime_bits - 100) || |
1102 | 0 | !BN_set_bit(pow2_prime_bits, prime_bits)) { |
1103 | 0 | goto bn_err; |
1104 | 0 | } |
1105 | | |
1106 | | // We need the RSA components non-NULL. |
1107 | 0 | if (!ensure_bignum(&rsa->n) || |
1108 | 0 | !ensure_bignum(&rsa->d) || |
1109 | 0 | !ensure_bignum(&rsa->e) || |
1110 | 0 | !ensure_bignum(&rsa->p) || |
1111 | 0 | !ensure_bignum(&rsa->q) || |
1112 | 0 | !ensure_bignum(&rsa->dmp1) || |
1113 | 0 | !ensure_bignum(&rsa->dmq1)) { |
1114 | 0 | goto bn_err; |
1115 | 0 | } |
1116 | | |
1117 | 0 | if (!BN_copy(rsa->e, e_value)) { |
1118 | 0 | goto bn_err; |
1119 | 0 | } |
1120 | | |
1121 | | // Compute sqrt2 >= ⌊2^(prime_bits-1)×√2⌋. |
1122 | 0 | if (!bn_set_words(sqrt2, kBoringSSLRSASqrtTwo, kBoringSSLRSASqrtTwoLen)) { |
1123 | 0 | goto bn_err; |
1124 | 0 | } |
1125 | 0 | int sqrt2_bits = kBoringSSLRSASqrtTwoLen * BN_BITS2; |
1126 | 0 | assert(sqrt2_bits == (int)BN_num_bits(sqrt2)); |
1127 | 0 | if (sqrt2_bits > prime_bits) { |
1128 | | // For key sizes up to 4096 (prime_bits = 2048), this is exactly |
1129 | | // ⌊2^(prime_bits-1)×√2⌋. |
1130 | 0 | if (!BN_rshift(sqrt2, sqrt2, sqrt2_bits - prime_bits)) { |
1131 | 0 | goto bn_err; |
1132 | 0 | } |
1133 | 0 | } else if (prime_bits > sqrt2_bits) { |
1134 | | // For key sizes beyond 4096, this is approximate. We err towards retrying |
1135 | | // to ensure our key is the right size and round up. |
1136 | 0 | if (!BN_add_word(sqrt2, 1) || |
1137 | 0 | !BN_lshift(sqrt2, sqrt2, prime_bits - sqrt2_bits)) { |
1138 | 0 | goto bn_err; |
1139 | 0 | } |
1140 | 0 | } |
1141 | 0 | assert(prime_bits == (int)BN_num_bits(sqrt2)); |
1142 | | |
1143 | 0 | do { |
1144 | | // Generate p and q, each of size |prime_bits|, using the steps outlined in |
1145 | | // appendix FIPS 186-4 appendix B.3.3. |
1146 | | // |
1147 | | // Each call to |generate_prime| fails with probability p = 2^-21. The |
1148 | | // probability that either call fails is 1 - (1-p)^2, which is around 2^-20. |
1149 | 0 | if (!generate_prime(rsa->p, prime_bits, rsa->e, NULL, sqrt2, |
1150 | 0 | pow2_prime_bits_100, ctx, cb) || |
1151 | 0 | !BN_GENCB_call(cb, 3, 0) || |
1152 | 0 | !generate_prime(rsa->q, prime_bits, rsa->e, rsa->p, sqrt2, |
1153 | 0 | pow2_prime_bits_100, ctx, cb) || |
1154 | 0 | !BN_GENCB_call(cb, 3, 1)) { |
1155 | 0 | goto bn_err; |
1156 | 0 | } |
1157 | | |
1158 | 0 | if (BN_cmp(rsa->p, rsa->q) < 0) { |
1159 | 0 | BIGNUM *tmp = rsa->p; |
1160 | 0 | rsa->p = rsa->q; |
1161 | 0 | rsa->q = tmp; |
1162 | 0 | } |
1163 | | |
1164 | | // Calculate d = e^(-1) (mod lcm(p-1, q-1)), per FIPS 186-4. This differs |
1165 | | // from typical RSA implementations which use (p-1)*(q-1). |
1166 | | // |
1167 | | // Note this means the size of d might reveal information about p-1 and |
1168 | | // q-1. However, we do operations with Chinese Remainder Theorem, so we only |
1169 | | // use d (mod p-1) and d (mod q-1) as exponents. Using a minimal totient |
1170 | | // does not affect those two values. |
1171 | 0 | int no_inverse; |
1172 | 0 | if (!bn_usub_consttime(pm1, rsa->p, BN_value_one()) || |
1173 | 0 | !bn_usub_consttime(qm1, rsa->q, BN_value_one()) || |
1174 | 0 | !bn_lcm_consttime(totient, pm1, qm1, ctx) || |
1175 | 0 | !bn_mod_inverse_consttime(rsa->d, &no_inverse, rsa->e, totient, ctx)) { |
1176 | 0 | goto bn_err; |
1177 | 0 | } |
1178 | | |
1179 | | // Retry if |rsa->d| <= 2^|prime_bits|. See appendix B.3.1's guidance on |
1180 | | // values for d. When we retry, p and q are discarded, so it is safe to leak |
1181 | | // this comparison. |
1182 | 0 | } while (constant_time_declassify_int(BN_cmp(rsa->d, pow2_prime_bits) <= 0)); |
1183 | | |
1184 | 0 | assert(BN_num_bits(pm1) == (unsigned)prime_bits); |
1185 | 0 | assert(BN_num_bits(qm1) == (unsigned)prime_bits); |
1186 | 0 | if (// Calculate n. |
1187 | 0 | !bn_mul_consttime(rsa->n, rsa->p, rsa->q, ctx) || |
1188 | | // Calculate d mod (p-1). |
1189 | 0 | !bn_div_consttime(NULL, rsa->dmp1, rsa->d, pm1, prime_bits, ctx) || |
1190 | | // Calculate d mod (q-1) |
1191 | 0 | !bn_div_consttime(NULL, rsa->dmq1, rsa->d, qm1, prime_bits, ctx)) { |
1192 | 0 | goto bn_err; |
1193 | 0 | } |
1194 | 0 | bn_set_minimal_width(rsa->n); |
1195 | | |
1196 | | // |rsa->n| is computed from the private key, but is public. |
1197 | 0 | bn_declassify(rsa->n); |
1198 | | |
1199 | | // Sanity-check that |rsa->n| has the specified size. This is implied by |
1200 | | // |generate_prime|'s bounds. |
1201 | 0 | if (BN_num_bits(rsa->n) != (unsigned)bits) { |
1202 | 0 | OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
1203 | 0 | goto err; |
1204 | 0 | } |
1205 | | |
1206 | | // Call |freeze_private_key| to compute the inverse of q mod p, by way of |
1207 | | // |rsa->mont_p|. |
1208 | 0 | if (!freeze_private_key(rsa, ctx)) { |
1209 | 0 | goto bn_err; |
1210 | 0 | } |
1211 | | |
1212 | | // The key generation process is complex and thus error-prone. It could be |
1213 | | // disastrous to generate and then use a bad key so double-check that the key |
1214 | | // makes sense. |
1215 | 0 | if (!RSA_check_key(rsa)) { |
1216 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_INTERNAL_ERROR); |
1217 | 0 | goto err; |
1218 | 0 | } |
1219 | | |
1220 | 0 | ret = 1; |
1221 | |
|
1222 | 0 | bn_err: |
1223 | 0 | if (!ret) { |
1224 | 0 | OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN); |
1225 | 0 | } |
1226 | 0 | err: |
1227 | 0 | if (ctx != NULL) { |
1228 | 0 | BN_CTX_end(ctx); |
1229 | 0 | BN_CTX_free(ctx); |
1230 | 0 | } |
1231 | 0 | return ret; |
1232 | 0 | } |
1233 | | |
1234 | 0 | static void replace_bignum(BIGNUM **out, BIGNUM **in) { |
1235 | 0 | BN_free(*out); |
1236 | 0 | *out = *in; |
1237 | 0 | *in = NULL; |
1238 | 0 | } |
1239 | | |
1240 | 0 | static void replace_bn_mont_ctx(BN_MONT_CTX **out, BN_MONT_CTX **in) { |
1241 | 0 | BN_MONT_CTX_free(*out); |
1242 | 0 | *out = *in; |
1243 | 0 | *in = NULL; |
1244 | 0 | } |
1245 | | |
1246 | | static int RSA_generate_key_ex_maybe_fips(RSA *rsa, int bits, |
1247 | | const BIGNUM *e_value, BN_GENCB *cb, |
1248 | 0 | int check_fips) { |
1249 | 0 | boringssl_ensure_rsa_self_test(); |
1250 | |
|
1251 | 0 | if (rsa == NULL) { |
1252 | 0 | OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER); |
1253 | 0 | return 0; |
1254 | 0 | } |
1255 | | |
1256 | 0 | RSA *tmp = NULL; |
1257 | 0 | uint32_t err; |
1258 | 0 | int ret = 0; |
1259 | | |
1260 | | // |rsa_generate_key_impl|'s 2^-20 failure probability is too high at scale, |
1261 | | // so we run the FIPS algorithm four times, bringing it down to 2^-80. We |
1262 | | // should just adjust the retry limit, but FIPS 186-4 prescribes that value |
1263 | | // and thus results in unnecessary complexity. |
1264 | 0 | int failures = 0; |
1265 | 0 | do { |
1266 | 0 | ERR_clear_error(); |
1267 | | // Generate into scratch space, to avoid leaving partial work on failure. |
1268 | 0 | tmp = RSA_new(); |
1269 | 0 | if (tmp == NULL) { |
1270 | 0 | goto out; |
1271 | 0 | } |
1272 | | |
1273 | 0 | if (rsa_generate_key_impl(tmp, bits, e_value, cb)) { |
1274 | 0 | break; |
1275 | 0 | } |
1276 | | |
1277 | 0 | err = ERR_peek_error(); |
1278 | 0 | RSA_free(tmp); |
1279 | 0 | tmp = NULL; |
1280 | 0 | failures++; |
1281 | | |
1282 | | // Only retry on |RSA_R_TOO_MANY_ITERATIONS|. This is so a caller-induced |
1283 | | // failure in |BN_GENCB_call| is still fatal. |
1284 | 0 | } while (failures < 4 && ERR_GET_LIB(err) == ERR_LIB_RSA && |
1285 | 0 | ERR_GET_REASON(err) == RSA_R_TOO_MANY_ITERATIONS); |
1286 | | |
1287 | 0 | if (tmp == NULL || (check_fips && !RSA_check_fips(tmp))) { |
1288 | 0 | goto out; |
1289 | 0 | } |
1290 | | |
1291 | 0 | rsa_invalidate_key(rsa); |
1292 | 0 | replace_bignum(&rsa->n, &tmp->n); |
1293 | 0 | replace_bignum(&rsa->e, &tmp->e); |
1294 | 0 | replace_bignum(&rsa->d, &tmp->d); |
1295 | 0 | replace_bignum(&rsa->p, &tmp->p); |
1296 | 0 | replace_bignum(&rsa->q, &tmp->q); |
1297 | 0 | replace_bignum(&rsa->dmp1, &tmp->dmp1); |
1298 | 0 | replace_bignum(&rsa->dmq1, &tmp->dmq1); |
1299 | 0 | replace_bignum(&rsa->iqmp, &tmp->iqmp); |
1300 | 0 | replace_bn_mont_ctx(&rsa->mont_n, &tmp->mont_n); |
1301 | 0 | replace_bn_mont_ctx(&rsa->mont_p, &tmp->mont_p); |
1302 | 0 | replace_bn_mont_ctx(&rsa->mont_q, &tmp->mont_q); |
1303 | 0 | replace_bignum(&rsa->d_fixed, &tmp->d_fixed); |
1304 | 0 | replace_bignum(&rsa->dmp1_fixed, &tmp->dmp1_fixed); |
1305 | 0 | replace_bignum(&rsa->dmq1_fixed, &tmp->dmq1_fixed); |
1306 | 0 | replace_bignum(&rsa->iqmp_mont, &tmp->iqmp_mont); |
1307 | 0 | rsa->private_key_frozen = tmp->private_key_frozen; |
1308 | 0 | ret = 1; |
1309 | |
|
1310 | 0 | out: |
1311 | 0 | RSA_free(tmp); |
1312 | 0 | return ret; |
1313 | 0 | } |
1314 | | |
1315 | | int RSA_generate_key_ex(RSA *rsa, int bits, const BIGNUM *e_value, |
1316 | 0 | BN_GENCB *cb) { |
1317 | 0 | return RSA_generate_key_ex_maybe_fips(rsa, bits, e_value, cb, |
1318 | 0 | /*check_fips=*/0); |
1319 | 0 | } |
1320 | | |
1321 | 0 | int RSA_generate_key_fips(RSA *rsa, int bits, BN_GENCB *cb) { |
1322 | | // FIPS 186-4 allows 2048-bit and 3072-bit RSA keys (1024-bit and 1536-bit |
1323 | | // primes, respectively) with the prime generation method we use. |
1324 | | // Subsequently, IG A.14 stated that larger modulus sizes can be used and ACVP |
1325 | | // testing supports 4096 bits. |
1326 | 0 | if (bits != 2048 && bits != 3072 && bits != 4096) { |
1327 | 0 | OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_RSA_PARAMETERS); |
1328 | 0 | return 0; |
1329 | 0 | } |
1330 | | |
1331 | 0 | BIGNUM *e = BN_new(); |
1332 | 0 | int ret = e != NULL && |
1333 | 0 | BN_set_word(e, RSA_F4) && |
1334 | 0 | RSA_generate_key_ex_maybe_fips(rsa, bits, e, cb, /*check_fips=*/1); |
1335 | 0 | BN_free(e); |
1336 | |
|
1337 | 0 | if (ret) { |
1338 | 0 | FIPS_service_indicator_update_state(); |
1339 | 0 | } |
1340 | 0 | return ret; |
1341 | 0 | } |
1342 | | |
1343 | 0 | DEFINE_METHOD_FUNCTION(RSA_METHOD, RSA_default_method) { |
1344 | | // All of the methods are NULL to make it easier for the compiler/linker to |
1345 | | // drop unused functions. The wrapper functions will select the appropriate |
1346 | | // |rsa_default_*| implementation. |
1347 | 0 | OPENSSL_memset(out, 0, sizeof(RSA_METHOD)); |
1348 | 0 | out->common.is_static = 1; |
1349 | 0 | } |