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Commit | Line | Data |
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2039c421 | 1 | /* |
8020d79b | 2 | * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved. |
46a64376 | 3 | * |
2a7b6f39 | 4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
2039c421 RS |
5 | * this file except in compliance with the License. You can obtain a copy |
6 | * in the file LICENSE in the source distribution or at | |
7 | * https://www.openssl.org/source/license.html | |
46a64376 | 8 | */ |
58964a49 | 9 | |
c5f87134 P |
10 | /* |
11 | * RSA low level APIs are deprecated for public use, but still ok for | |
12 | * internal use. | |
13 | */ | |
14 | #include "internal/deprecated.h" | |
15 | ||
b39fc560 | 16 | #include "internal/cryptlib.h" |
25f2138b | 17 | #include "crypto/bn.h" |
706457b7 DMSP |
18 | #include "rsa_local.h" |
19 | #include "internal/constant_time.h" | |
58964a49 | 20 | |
bf160551 | 21 | static int rsa_ossl_public_encrypt(int flen, const unsigned char *from, |
0f113f3e | 22 | unsigned char *to, RSA *rsa, int padding); |
bf160551 | 23 | static int rsa_ossl_private_encrypt(int flen, const unsigned char *from, |
0f113f3e | 24 | unsigned char *to, RSA *rsa, int padding); |
bf160551 | 25 | static int rsa_ossl_public_decrypt(int flen, const unsigned char *from, |
0f113f3e | 26 | unsigned char *to, RSA *rsa, int padding); |
bf160551 | 27 | static int rsa_ossl_private_decrypt(int flen, const unsigned char *from, |
0f113f3e | 28 | unsigned char *to, RSA *rsa, int padding); |
bf160551 | 29 | static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa, |
0f113f3e | 30 | BN_CTX *ctx); |
bf160551 RS |
31 | static int rsa_ossl_init(RSA *rsa); |
32 | static int rsa_ossl_finish(RSA *rsa); | |
33 | static RSA_METHOD rsa_pkcs1_ossl_meth = { | |
076fc555 | 34 | "OpenSSL PKCS#1 RSA", |
bf160551 RS |
35 | rsa_ossl_public_encrypt, |
36 | rsa_ossl_public_decrypt, /* signature verification */ | |
37 | rsa_ossl_private_encrypt, /* signing */ | |
38 | rsa_ossl_private_decrypt, | |
39 | rsa_ossl_mod_exp, | |
0f113f3e MC |
40 | BN_mod_exp_mont, /* XXX probably we should not use Montgomery |
41 | * if e == 3 */ | |
bf160551 RS |
42 | rsa_ossl_init, |
43 | rsa_ossl_finish, | |
0f113f3e MC |
44 | RSA_FLAG_FIPS_METHOD, /* flags */ |
45 | NULL, | |
46 | 0, /* rsa_sign */ | |
47 | 0, /* rsa_verify */ | |
665d899f PY |
48 | NULL, /* rsa_keygen */ |
49 | NULL /* rsa_multi_prime_keygen */ | |
0f113f3e | 50 | }; |
58964a49 | 51 | |
076fc555 RS |
52 | static const RSA_METHOD *default_RSA_meth = &rsa_pkcs1_ossl_meth; |
53 | ||
54 | void RSA_set_default_method(const RSA_METHOD *meth) | |
55 | { | |
56 | default_RSA_meth = meth; | |
57 | } | |
58 | ||
59 | const RSA_METHOD *RSA_get_default_method(void) | |
60 | { | |
61 | return default_RSA_meth; | |
62 | } | |
63 | ||
b0700d2c | 64 | const RSA_METHOD *RSA_PKCS1_OpenSSL(void) |
0f113f3e | 65 | { |
bf160551 | 66 | return &rsa_pkcs1_ossl_meth; |
0f113f3e | 67 | } |
58964a49 | 68 | |
076fc555 RS |
69 | const RSA_METHOD *RSA_null_method(void) |
70 | { | |
71 | return NULL; | |
72 | } | |
73 | ||
bf160551 | 74 | static int rsa_ossl_public_encrypt(int flen, const unsigned char *from, |
0f113f3e MC |
75 | unsigned char *to, RSA *rsa, int padding) |
76 | { | |
77 | BIGNUM *f, *ret; | |
582ad5d4 | 78 | int i, num = 0, r = -1; |
0f113f3e MC |
79 | unsigned char *buf = NULL; |
80 | BN_CTX *ctx = NULL; | |
81 | ||
82 | if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) { | |
9311d0c4 | 83 | ERR_raise(ERR_LIB_RSA, RSA_R_MODULUS_TOO_LARGE); |
0f113f3e MC |
84 | return -1; |
85 | } | |
86 | ||
87 | if (BN_ucmp(rsa->n, rsa->e) <= 0) { | |
9311d0c4 | 88 | ERR_raise(ERR_LIB_RSA, RSA_R_BAD_E_VALUE); |
0f113f3e MC |
89 | return -1; |
90 | } | |
91 | ||
92 | /* for large moduli, enforce exponent limit */ | |
93 | if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) { | |
94 | if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) { | |
9311d0c4 | 95 | ERR_raise(ERR_LIB_RSA, RSA_R_BAD_E_VALUE); |
0f113f3e MC |
96 | return -1; |
97 | } | |
98 | } | |
99 | ||
afb638f1 | 100 | if ((ctx = BN_CTX_new_ex(rsa->libctx)) == NULL) |
0f113f3e MC |
101 | goto err; |
102 | BN_CTX_start(ctx); | |
103 | f = BN_CTX_get(ctx); | |
104 | ret = BN_CTX_get(ctx); | |
105 | num = BN_num_bytes(rsa->n); | |
106 | buf = OPENSSL_malloc(num); | |
edea42c6 | 107 | if (ret == NULL || buf == NULL) { |
9311d0c4 | 108 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
0f113f3e MC |
109 | goto err; |
110 | } | |
111 | ||
112 | switch (padding) { | |
113 | case RSA_PKCS1_PADDING: | |
23b2fc0b P |
114 | i = ossl_rsa_padding_add_PKCS1_type_2_ex(rsa->libctx, buf, num, |
115 | from, flen); | |
0f113f3e | 116 | break; |
0f113f3e | 117 | case RSA_PKCS1_OAEP_PADDING: |
23b2fc0b P |
118 | i = ossl_rsa_padding_add_PKCS1_OAEP_mgf1_ex(rsa->libctx, buf, num, |
119 | from, flen, NULL, 0, | |
120 | NULL, NULL); | |
0f113f3e | 121 | break; |
0f113f3e MC |
122 | case RSA_NO_PADDING: |
123 | i = RSA_padding_add_none(buf, num, from, flen); | |
124 | break; | |
125 | default: | |
9311d0c4 | 126 | ERR_raise(ERR_LIB_RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
0f113f3e MC |
127 | goto err; |
128 | } | |
129 | if (i <= 0) | |
130 | goto err; | |
131 | ||
132 | if (BN_bin2bn(buf, num, f) == NULL) | |
133 | goto err; | |
134 | ||
135 | if (BN_ucmp(f, rsa->n) >= 0) { | |
136 | /* usually the padding functions would catch this */ | |
9311d0c4 | 137 | ERR_raise(ERR_LIB_RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
0f113f3e MC |
138 | goto err; |
139 | } | |
140 | ||
141 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) | |
41bfd5e7 AP |
142 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock, |
143 | rsa->n, ctx)) | |
0f113f3e MC |
144 | goto err; |
145 | ||
146 | if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx, | |
147 | rsa->_method_mod_n)) | |
148 | goto err; | |
149 | ||
150 | /* | |
582ad5d4 AP |
151 | * BN_bn2binpad puts in leading 0 bytes if the number is less than |
152 | * the length of the modulus. | |
0f113f3e | 153 | */ |
582ad5d4 | 154 | r = BN_bn2binpad(ret, to, num); |
0f113f3e | 155 | err: |
ce1415ed | 156 | BN_CTX_end(ctx); |
23a1d5e9 | 157 | BN_CTX_free(ctx); |
4b45c6e5 | 158 | OPENSSL_clear_free(buf, num); |
8686c474 | 159 | return r; |
0f113f3e | 160 | } |
58964a49 | 161 | |
675f605d | 162 | static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx) |
800e400d | 163 | { |
0f113f3e | 164 | BN_BLINDING *ret; |
0f113f3e | 165 | |
cd3f8c1b RS |
166 | if (!CRYPTO_THREAD_write_lock(rsa->lock)) |
167 | return NULL; | |
0f113f3e MC |
168 | |
169 | if (rsa->blinding == NULL) { | |
d188a536 | 170 | rsa->blinding = RSA_setup_blinding(rsa, ctx); |
0f113f3e MC |
171 | } |
172 | ||
173 | ret = rsa->blinding; | |
174 | if (ret == NULL) | |
175 | goto err; | |
176 | ||
0b1a07c8 | 177 | if (BN_BLINDING_is_current_thread(ret)) { |
0f113f3e MC |
178 | /* rsa->blinding is ours! */ |
179 | ||
180 | *local = 1; | |
181 | } else { | |
182 | /* resort to rsa->mt_blinding instead */ | |
183 | ||
184 | /* | |
185 | * instructs rsa_blinding_convert(), rsa_blinding_invert() that the | |
186 | * BN_BLINDING is shared, meaning that accesses require locks, and | |
187 | * that the blinding factor must be stored outside the BN_BLINDING | |
188 | */ | |
189 | *local = 0; | |
190 | ||
191 | if (rsa->mt_blinding == NULL) { | |
d188a536 | 192 | rsa->mt_blinding = RSA_setup_blinding(rsa, ctx); |
0f113f3e MC |
193 | } |
194 | ret = rsa->mt_blinding; | |
195 | } | |
5679bcce | 196 | |
675f605d | 197 | err: |
d188a536 | 198 | CRYPTO_THREAD_unlock(rsa->lock); |
0f113f3e | 199 | return ret; |
800e400d | 200 | } |
5679bcce | 201 | |
e5641d7f | 202 | static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, |
0f113f3e MC |
203 | BN_CTX *ctx) |
204 | { | |
90862ab4 | 205 | if (unblind == NULL) { |
0f113f3e MC |
206 | /* |
207 | * Local blinding: store the unblinding factor in BN_BLINDING. | |
208 | */ | |
209 | return BN_BLINDING_convert_ex(f, NULL, b, ctx); | |
90862ab4 | 210 | } else { |
0f113f3e MC |
211 | /* |
212 | * Shared blinding: store the unblinding factor outside BN_BLINDING. | |
213 | */ | |
214 | int ret; | |
0b1a07c8 | 215 | |
aefbcde2 JJ |
216 | if (!BN_BLINDING_lock(b)) |
217 | return 0; | |
218 | ||
0f113f3e | 219 | ret = BN_BLINDING_convert_ex(f, unblind, b, ctx); |
0b1a07c8 AG |
220 | BN_BLINDING_unlock(b); |
221 | ||
0f113f3e MC |
222 | return ret; |
223 | } | |
224 | } | |
e5641d7f BM |
225 | |
226 | static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, | |
0f113f3e MC |
227 | BN_CTX *ctx) |
228 | { | |
229 | /* | |
230 | * For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex | |
231 | * will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING | |
232 | * is shared between threads, unblind must be non-null: | |
233 | * BN_BLINDING_invert_ex will then use the local unblinding factor, and | |
234 | * will only read the modulus from BN_BLINDING. In both cases it's safe | |
235 | * to access the blinding without a lock. | |
236 | */ | |
237 | return BN_BLINDING_invert_ex(f, unblind, b, ctx); | |
238 | } | |
5679bcce | 239 | |
24cff6ce | 240 | /* signing */ |
bf160551 | 241 | static int rsa_ossl_private_encrypt(int flen, const unsigned char *from, |
0f113f3e MC |
242 | unsigned char *to, RSA *rsa, int padding) |
243 | { | |
244 | BIGNUM *f, *ret, *res; | |
582ad5d4 | 245 | int i, num = 0, r = -1; |
0f113f3e MC |
246 | unsigned char *buf = NULL; |
247 | BN_CTX *ctx = NULL; | |
248 | int local_blinding = 0; | |
249 | /* | |
250 | * Used only if the blinding structure is shared. A non-NULL unblind | |
251 | * instructs rsa_blinding_convert() and rsa_blinding_invert() to store | |
252 | * the unblinding factor outside the blinding structure. | |
253 | */ | |
254 | BIGNUM *unblind = NULL; | |
255 | BN_BLINDING *blinding = NULL; | |
256 | ||
afb638f1 | 257 | if ((ctx = BN_CTX_new_ex(rsa->libctx)) == NULL) |
0f113f3e MC |
258 | goto err; |
259 | BN_CTX_start(ctx); | |
260 | f = BN_CTX_get(ctx); | |
261 | ret = BN_CTX_get(ctx); | |
262 | num = BN_num_bytes(rsa->n); | |
263 | buf = OPENSSL_malloc(num); | |
edea42c6 | 264 | if (ret == NULL || buf == NULL) { |
9311d0c4 | 265 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
0f113f3e MC |
266 | goto err; |
267 | } | |
268 | ||
269 | switch (padding) { | |
270 | case RSA_PKCS1_PADDING: | |
271 | i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen); | |
272 | break; | |
273 | case RSA_X931_PADDING: | |
274 | i = RSA_padding_add_X931(buf, num, from, flen); | |
275 | break; | |
276 | case RSA_NO_PADDING: | |
277 | i = RSA_padding_add_none(buf, num, from, flen); | |
278 | break; | |
0f113f3e | 279 | default: |
9311d0c4 | 280 | ERR_raise(ERR_LIB_RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
0f113f3e MC |
281 | goto err; |
282 | } | |
283 | if (i <= 0) | |
284 | goto err; | |
285 | ||
286 | if (BN_bin2bn(buf, num, f) == NULL) | |
287 | goto err; | |
288 | ||
289 | if (BN_ucmp(f, rsa->n) >= 0) { | |
290 | /* usually the padding functions would catch this */ | |
9311d0c4 | 291 | ERR_raise(ERR_LIB_RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
0f113f3e MC |
292 | goto err; |
293 | } | |
294 | ||
2cc3f68c AP |
295 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) |
296 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock, | |
297 | rsa->n, ctx)) | |
298 | goto err; | |
299 | ||
0f113f3e MC |
300 | if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) { |
301 | blinding = rsa_get_blinding(rsa, &local_blinding, ctx); | |
302 | if (blinding == NULL) { | |
9311d0c4 | 303 | ERR_raise(ERR_LIB_RSA, ERR_R_INTERNAL_ERROR); |
0f113f3e MC |
304 | goto err; |
305 | } | |
306 | } | |
307 | ||
308 | if (blinding != NULL) { | |
309 | if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) { | |
9311d0c4 | 310 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
0f113f3e MC |
311 | goto err; |
312 | } | |
313 | if (!rsa_blinding_convert(blinding, f, unblind, ctx)) | |
314 | goto err; | |
315 | } | |
316 | ||
317 | if ((rsa->flags & RSA_FLAG_EXT_PKEY) || | |
665d899f | 318 | (rsa->version == RSA_ASN1_VERSION_MULTI) || |
0f113f3e MC |
319 | ((rsa->p != NULL) && |
320 | (rsa->q != NULL) && | |
321 | (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) { | |
322 | if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) | |
323 | goto err; | |
324 | } else { | |
5584f65a MC |
325 | BIGNUM *d = BN_new(); |
326 | if (d == NULL) { | |
9311d0c4 | 327 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
5584f65a | 328 | goto err; |
fd7d2520 | 329 | } |
7408f675 | 330 | if (rsa->d == NULL) { |
9311d0c4 | 331 | ERR_raise(ERR_LIB_RSA, RSA_R_MISSING_PRIVATE_KEY); |
7408f675 DO |
332 | BN_free(d); |
333 | goto err; | |
334 | } | |
5584f65a | 335 | BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); |
0f113f3e | 336 | |
0f113f3e MC |
337 | if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx, |
338 | rsa->_method_mod_n)) { | |
5584f65a | 339 | BN_free(d); |
0f113f3e MC |
340 | goto err; |
341 | } | |
5584f65a MC |
342 | /* We MUST free d before any further use of rsa->d */ |
343 | BN_free(d); | |
0f113f3e MC |
344 | } |
345 | ||
346 | if (blinding) | |
347 | if (!rsa_blinding_invert(blinding, ret, unblind, ctx)) | |
348 | goto err; | |
349 | ||
350 | if (padding == RSA_X931_PADDING) { | |
3d3cbce5 P |
351 | if (!BN_sub(f, rsa->n, ret)) |
352 | goto err; | |
0f113f3e MC |
353 | if (BN_cmp(ret, f) > 0) |
354 | res = f; | |
355 | else | |
356 | res = ret; | |
90862ab4 | 357 | } else { |
0f113f3e | 358 | res = ret; |
90862ab4 | 359 | } |
0f113f3e MC |
360 | |
361 | /* | |
582ad5d4 AP |
362 | * BN_bn2binpad puts in leading 0 bytes if the number is less than |
363 | * the length of the modulus. | |
0f113f3e | 364 | */ |
582ad5d4 | 365 | r = BN_bn2binpad(res, to, num); |
0f113f3e | 366 | err: |
ce1415ed | 367 | BN_CTX_end(ctx); |
23a1d5e9 | 368 | BN_CTX_free(ctx); |
4b45c6e5 | 369 | OPENSSL_clear_free(buf, num); |
8686c474 | 370 | return r; |
0f113f3e | 371 | } |
58964a49 | 372 | |
bf160551 | 373 | static int rsa_ossl_private_decrypt(int flen, const unsigned char *from, |
0f113f3e MC |
374 | unsigned char *to, RSA *rsa, int padding) |
375 | { | |
376 | BIGNUM *f, *ret; | |
377 | int j, num = 0, r = -1; | |
0f113f3e MC |
378 | unsigned char *buf = NULL; |
379 | BN_CTX *ctx = NULL; | |
380 | int local_blinding = 0; | |
381 | /* | |
382 | * Used only if the blinding structure is shared. A non-NULL unblind | |
383 | * instructs rsa_blinding_convert() and rsa_blinding_invert() to store | |
384 | * the unblinding factor outside the blinding structure. | |
385 | */ | |
386 | BIGNUM *unblind = NULL; | |
387 | BN_BLINDING *blinding = NULL; | |
388 | ||
afb638f1 | 389 | if ((ctx = BN_CTX_new_ex(rsa->libctx)) == NULL) |
0f113f3e MC |
390 | goto err; |
391 | BN_CTX_start(ctx); | |
392 | f = BN_CTX_get(ctx); | |
393 | ret = BN_CTX_get(ctx); | |
394 | num = BN_num_bytes(rsa->n); | |
395 | buf = OPENSSL_malloc(num); | |
edea42c6 | 396 | if (ret == NULL || buf == NULL) { |
9311d0c4 | 397 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
0f113f3e MC |
398 | goto err; |
399 | } | |
400 | ||
401 | /* | |
402 | * This check was for equality but PGP does evil things and chops off the | |
403 | * top '0' bytes | |
404 | */ | |
405 | if (flen > num) { | |
9311d0c4 | 406 | ERR_raise(ERR_LIB_RSA, RSA_R_DATA_GREATER_THAN_MOD_LEN); |
0f113f3e MC |
407 | goto err; |
408 | } | |
409 | ||
410 | /* make data into a big number */ | |
411 | if (BN_bin2bn(from, (int)flen, f) == NULL) | |
412 | goto err; | |
413 | ||
414 | if (BN_ucmp(f, rsa->n) >= 0) { | |
9311d0c4 | 415 | ERR_raise(ERR_LIB_RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
0f113f3e MC |
416 | goto err; |
417 | } | |
418 | ||
419 | if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) { | |
420 | blinding = rsa_get_blinding(rsa, &local_blinding, ctx); | |
421 | if (blinding == NULL) { | |
9311d0c4 | 422 | ERR_raise(ERR_LIB_RSA, ERR_R_INTERNAL_ERROR); |
0f113f3e MC |
423 | goto err; |
424 | } | |
425 | } | |
426 | ||
427 | if (blinding != NULL) { | |
428 | if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) { | |
9311d0c4 | 429 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
0f113f3e MC |
430 | goto err; |
431 | } | |
432 | if (!rsa_blinding_convert(blinding, f, unblind, ctx)) | |
433 | goto err; | |
434 | } | |
435 | ||
436 | /* do the decrypt */ | |
437 | if ((rsa->flags & RSA_FLAG_EXT_PKEY) || | |
665d899f | 438 | (rsa->version == RSA_ASN1_VERSION_MULTI) || |
0f113f3e MC |
439 | ((rsa->p != NULL) && |
440 | (rsa->q != NULL) && | |
441 | (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) { | |
442 | if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) | |
443 | goto err; | |
444 | } else { | |
5584f65a MC |
445 | BIGNUM *d = BN_new(); |
446 | if (d == NULL) { | |
9311d0c4 | 447 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
5584f65a | 448 | goto err; |
7408f675 DO |
449 | } |
450 | if (rsa->d == NULL) { | |
9311d0c4 | 451 | ERR_raise(ERR_LIB_RSA, RSA_R_MISSING_PRIVATE_KEY); |
7408f675 DO |
452 | BN_free(d); |
453 | goto err; | |
fd7d2520 | 454 | } |
5584f65a | 455 | BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); |
0f113f3e MC |
456 | |
457 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) | |
41bfd5e7 AP |
458 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock, |
459 | rsa->n, ctx)) { | |
5584f65a | 460 | BN_free(d); |
0f113f3e MC |
461 | goto err; |
462 | } | |
463 | if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx, | |
464 | rsa->_method_mod_n)) { | |
5584f65a | 465 | BN_free(d); |
0f113f3e MC |
466 | goto err; |
467 | } | |
5584f65a MC |
468 | /* We MUST free d before any further use of rsa->d */ |
469 | BN_free(d); | |
0f113f3e MC |
470 | } |
471 | ||
472 | if (blinding) | |
473 | if (!rsa_blinding_invert(blinding, ret, unblind, ctx)) | |
474 | goto err; | |
475 | ||
582ad5d4 | 476 | j = BN_bn2binpad(ret, buf, num); |
4a3dd629 P |
477 | if (j < 0) |
478 | goto err; | |
0f113f3e MC |
479 | |
480 | switch (padding) { | |
481 | case RSA_PKCS1_PADDING: | |
482 | r = RSA_padding_check_PKCS1_type_2(to, num, buf, j, num); | |
483 | break; | |
0f113f3e MC |
484 | case RSA_PKCS1_OAEP_PADDING: |
485 | r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0); | |
486 | break; | |
0f113f3e | 487 | case RSA_NO_PADDING: |
582ad5d4 | 488 | memcpy(to, buf, (r = j)); |
0f113f3e MC |
489 | break; |
490 | default: | |
9311d0c4 | 491 | ERR_raise(ERR_LIB_RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
0f113f3e MC |
492 | goto err; |
493 | } | |
f844f9eb | 494 | #ifndef FIPS_MODULE |
afb638f1 MC |
495 | /* |
496 | * This trick doesn't work in the FIPS provider because libcrypto manages | |
497 | * the error stack. Instead we opt not to put an error on the stack at all | |
498 | * in case of padding failure in the FIPS provider. | |
499 | */ | |
9311d0c4 | 500 | ERR_raise(ERR_LIB_RSA, RSA_R_PADDING_CHECK_FAILED); |
94dc53a3 | 501 | err_clear_last_constant_time(1 & ~constant_time_msb(r)); |
afb638f1 | 502 | #endif |
0f113f3e MC |
503 | |
504 | err: | |
ce1415ed | 505 | BN_CTX_end(ctx); |
23a1d5e9 | 506 | BN_CTX_free(ctx); |
4b45c6e5 | 507 | OPENSSL_clear_free(buf, num); |
8686c474 | 508 | return r; |
0f113f3e | 509 | } |
58964a49 | 510 | |
24cff6ce | 511 | /* signature verification */ |
bf160551 | 512 | static int rsa_ossl_public_decrypt(int flen, const unsigned char *from, |
0f113f3e MC |
513 | unsigned char *to, RSA *rsa, int padding) |
514 | { | |
515 | BIGNUM *f, *ret; | |
516 | int i, num = 0, r = -1; | |
0f113f3e MC |
517 | unsigned char *buf = NULL; |
518 | BN_CTX *ctx = NULL; | |
519 | ||
520 | if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) { | |
9311d0c4 | 521 | ERR_raise(ERR_LIB_RSA, RSA_R_MODULUS_TOO_LARGE); |
0f113f3e MC |
522 | return -1; |
523 | } | |
524 | ||
525 | if (BN_ucmp(rsa->n, rsa->e) <= 0) { | |
9311d0c4 | 526 | ERR_raise(ERR_LIB_RSA, RSA_R_BAD_E_VALUE); |
0f113f3e MC |
527 | return -1; |
528 | } | |
529 | ||
530 | /* for large moduli, enforce exponent limit */ | |
531 | if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) { | |
532 | if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) { | |
9311d0c4 | 533 | ERR_raise(ERR_LIB_RSA, RSA_R_BAD_E_VALUE); |
0f113f3e MC |
534 | return -1; |
535 | } | |
536 | } | |
537 | ||
afb638f1 | 538 | if ((ctx = BN_CTX_new_ex(rsa->libctx)) == NULL) |
0f113f3e MC |
539 | goto err; |
540 | BN_CTX_start(ctx); | |
541 | f = BN_CTX_get(ctx); | |
542 | ret = BN_CTX_get(ctx); | |
543 | num = BN_num_bytes(rsa->n); | |
544 | buf = OPENSSL_malloc(num); | |
edea42c6 | 545 | if (ret == NULL || buf == NULL) { |
9311d0c4 | 546 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
0f113f3e MC |
547 | goto err; |
548 | } | |
549 | ||
550 | /* | |
551 | * This check was for equality but PGP does evil things and chops off the | |
552 | * top '0' bytes | |
553 | */ | |
554 | if (flen > num) { | |
9311d0c4 | 555 | ERR_raise(ERR_LIB_RSA, RSA_R_DATA_GREATER_THAN_MOD_LEN); |
0f113f3e MC |
556 | goto err; |
557 | } | |
558 | ||
559 | if (BN_bin2bn(from, flen, f) == NULL) | |
560 | goto err; | |
561 | ||
562 | if (BN_ucmp(f, rsa->n) >= 0) { | |
9311d0c4 | 563 | ERR_raise(ERR_LIB_RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
0f113f3e MC |
564 | goto err; |
565 | } | |
566 | ||
567 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) | |
41bfd5e7 AP |
568 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock, |
569 | rsa->n, ctx)) | |
0f113f3e MC |
570 | goto err; |
571 | ||
572 | if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx, | |
573 | rsa->_method_mod_n)) | |
574 | goto err; | |
575 | ||
576 | if ((padding == RSA_X931_PADDING) && ((bn_get_words(ret)[0] & 0xf) != 12)) | |
577 | if (!BN_sub(ret, rsa->n, ret)) | |
578 | goto err; | |
579 | ||
582ad5d4 | 580 | i = BN_bn2binpad(ret, buf, num); |
4a3dd629 P |
581 | if (i < 0) |
582 | goto err; | |
0f113f3e MC |
583 | |
584 | switch (padding) { | |
585 | case RSA_PKCS1_PADDING: | |
586 | r = RSA_padding_check_PKCS1_type_1(to, num, buf, i, num); | |
587 | break; | |
588 | case RSA_X931_PADDING: | |
589 | r = RSA_padding_check_X931(to, num, buf, i, num); | |
590 | break; | |
591 | case RSA_NO_PADDING: | |
582ad5d4 | 592 | memcpy(to, buf, (r = i)); |
0f113f3e MC |
593 | break; |
594 | default: | |
9311d0c4 | 595 | ERR_raise(ERR_LIB_RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
0f113f3e MC |
596 | goto err; |
597 | } | |
598 | if (r < 0) | |
9311d0c4 | 599 | ERR_raise(ERR_LIB_RSA, RSA_R_PADDING_CHECK_FAILED); |
0f113f3e MC |
600 | |
601 | err: | |
ce1415ed | 602 | BN_CTX_end(ctx); |
23a1d5e9 | 603 | BN_CTX_free(ctx); |
4b45c6e5 | 604 | OPENSSL_clear_free(buf, num); |
8686c474 | 605 | return r; |
0f113f3e | 606 | } |
58964a49 | 607 | |
bf160551 | 608 | static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) |
0f113f3e | 609 | { |
afb638f1 MC |
610 | BIGNUM *r1, *m1, *vrfy; |
611 | int ret = 0, smooth = 0; | |
f844f9eb | 612 | #ifndef FIPS_MODULE |
afb638f1 MC |
613 | BIGNUM *r2, *m[RSA_MAX_PRIME_NUM - 2]; |
614 | int i, ex_primes = 0; | |
665d899f | 615 | RSA_PRIME_INFO *pinfo; |
afb638f1 | 616 | #endif |
0f113f3e | 617 | |
c804d23d PC |
618 | BN_CTX_start(ctx); |
619 | ||
0f113f3e | 620 | r1 = BN_CTX_get(ctx); |
f844f9eb | 621 | #ifndef FIPS_MODULE |
665d899f | 622 | r2 = BN_CTX_get(ctx); |
afb638f1 | 623 | #endif |
0f113f3e MC |
624 | m1 = BN_CTX_get(ctx); |
625 | vrfy = BN_CTX_get(ctx); | |
5625567f BE |
626 | if (vrfy == NULL) |
627 | goto err; | |
0f113f3e | 628 | |
f844f9eb | 629 | #ifndef FIPS_MODULE |
665d899f | 630 | if (rsa->version == RSA_ASN1_VERSION_MULTI |
a1471588 BE |
631 | && ((ex_primes = sk_RSA_PRIME_INFO_num(rsa->prime_infos)) <= 0 |
632 | || ex_primes > RSA_MAX_PRIME_NUM - 2)) | |
665d899f | 633 | goto err; |
afb638f1 | 634 | #endif |
665d899f | 635 | |
41bfd5e7 AP |
636 | if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) { |
637 | BIGNUM *factor = BN_new(); | |
638 | ||
639 | if (factor == NULL) | |
640 | goto err; | |
0f113f3e MC |
641 | |
642 | /* | |
0d4fb843 | 643 | * Make sure BN_mod_inverse in Montgomery initialization uses the |
5584f65a | 644 | * BN_FLG_CONSTTIME flag |
0f113f3e | 645 | */ |
41bfd5e7 AP |
646 | if (!(BN_with_flags(factor, rsa->p, BN_FLG_CONSTTIME), |
647 | BN_MONT_CTX_set_locked(&rsa->_method_mod_p, rsa->lock, | |
648 | factor, ctx)) | |
649 | || !(BN_with_flags(factor, rsa->q, BN_FLG_CONSTTIME), | |
650 | BN_MONT_CTX_set_locked(&rsa->_method_mod_q, rsa->lock, | |
651 | factor, ctx))) { | |
652 | BN_free(factor); | |
5584f65a | 653 | goto err; |
0f113f3e | 654 | } |
f844f9eb | 655 | #ifndef FIPS_MODULE |
41bfd5e7 AP |
656 | for (i = 0; i < ex_primes; i++) { |
657 | pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i); | |
658 | BN_with_flags(factor, pinfo->r, BN_FLG_CONSTTIME); | |
659 | if (!BN_MONT_CTX_set_locked(&pinfo->m, rsa->lock, factor, ctx)) { | |
660 | BN_free(factor); | |
0f113f3e MC |
661 | goto err; |
662 | } | |
663 | } | |
afb638f1 | 664 | #endif |
fd7d2520 | 665 | /* |
41bfd5e7 | 666 | * We MUST free |factor| before any further use of the prime factors |
fd7d2520 | 667 | */ |
41bfd5e7 AP |
668 | BN_free(factor); |
669 | ||
afb638f1 | 670 | smooth = (rsa->meth->bn_mod_exp == BN_mod_exp_mont) |
f844f9eb | 671 | #ifndef FIPS_MODULE |
afb638f1 MC |
672 | && (ex_primes == 0) |
673 | #endif | |
41bfd5e7 | 674 | && (BN_num_bits(rsa->q) == BN_num_bits(rsa->p)); |
0f113f3e MC |
675 | } |
676 | ||
677 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) | |
41bfd5e7 AP |
678 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock, |
679 | rsa->n, ctx)) | |
680 | goto err; | |
681 | ||
682 | if (smooth) { | |
683 | /* | |
684 | * Conversion from Montgomery domain, a.k.a. Montgomery reduction, | |
685 | * accepts values in [0-m*2^w) range. w is m's bit width rounded up | |
686 | * to limb width. So that at the very least if |I| is fully reduced, | |
687 | * i.e. less than p*q, we can count on from-to round to perform | |
688 | * below modulo operations on |I|. Unlike BN_mod it's constant time. | |
689 | */ | |
690 | if (/* m1 = I moq q */ | |
691 | !bn_from_mont_fixed_top(m1, I, rsa->_method_mod_q, ctx) | |
692 | || !bn_to_mont_fixed_top(m1, m1, rsa->_method_mod_q, ctx) | |
41bfd5e7 AP |
693 | /* r1 = I mod p */ |
694 | || !bn_from_mont_fixed_top(r1, I, rsa->_method_mod_p, ctx) | |
695 | || !bn_to_mont_fixed_top(r1, r1, rsa->_method_mod_p, ctx) | |
c781eb1c AM |
696 | /* |
697 | * Use parallel exponentiations optimization if possible, | |
698 | * otherwise fallback to two sequential exponentiations: | |
699 | * m1 = m1^dmq1 mod q | |
700 | * r1 = r1^dmp1 mod p | |
701 | */ | |
702 | || !BN_mod_exp_mont_consttime_x2(m1, m1, rsa->dmq1, rsa->q, | |
703 | rsa->_method_mod_q, | |
704 | r1, r1, rsa->dmp1, rsa->p, | |
705 | rsa->_method_mod_p, | |
706 | ctx) | |
41bfd5e7 AP |
707 | /* r1 = (r1 - m1) mod p */ |
708 | /* | |
709 | * bn_mod_sub_fixed_top is not regular modular subtraction, | |
710 | * it can tolerate subtrahend to be larger than modulus, but | |
711 | * not bit-wise wider. This makes up for uncommon q>p case, | |
712 | * when |m1| can be larger than |rsa->p|. | |
713 | */ | |
714 | || !bn_mod_sub_fixed_top(r1, r1, m1, rsa->p) | |
715 | ||
d1c008f6 | 716 | /* r1 = r1 * iqmp mod p */ |
41bfd5e7 AP |
717 | || !bn_to_mont_fixed_top(r1, r1, rsa->_method_mod_p, ctx) |
718 | || !bn_mul_mont_fixed_top(r1, r1, rsa->iqmp, rsa->_method_mod_p, | |
719 | ctx) | |
d1c008f6 | 720 | /* r0 = r1 * q + m1 */ |
41bfd5e7 AP |
721 | || !bn_mul_fixed_top(r0, r1, rsa->q, ctx) |
722 | || !bn_mod_add_fixed_top(r0, r0, m1, rsa->n)) | |
0f113f3e MC |
723 | goto err; |
724 | ||
41bfd5e7 AP |
725 | goto tail; |
726 | } | |
727 | ||
0f113f3e | 728 | /* compute I mod q */ |
fd7d2520 | 729 | { |
5584f65a MC |
730 | BIGNUM *c = BN_new(); |
731 | if (c == NULL) | |
732 | goto err; | |
733 | BN_with_flags(c, I, BN_FLG_CONSTTIME); | |
734 | ||
fd7d2520 | 735 | if (!BN_mod(r1, c, rsa->q, ctx)) { |
5584f65a | 736 | BN_free(c); |
0f113f3e | 737 | goto err; |
fd7d2520 | 738 | } |
0f113f3e | 739 | |
fd7d2520 | 740 | { |
5584f65a MC |
741 | BIGNUM *dmq1 = BN_new(); |
742 | if (dmq1 == NULL) { | |
743 | BN_free(c); | |
744 | goto err; | |
fd7d2520 | 745 | } |
5584f65a MC |
746 | BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME); |
747 | ||
748 | /* compute r1^dmq1 mod q */ | |
fd7d2520 | 749 | if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx, |
41bfd5e7 | 750 | rsa->_method_mod_q)) { |
5584f65a MC |
751 | BN_free(c); |
752 | BN_free(dmq1); | |
fd7d2520 MC |
753 | goto err; |
754 | } | |
5584f65a MC |
755 | /* We MUST free dmq1 before any further use of rsa->dmq1 */ |
756 | BN_free(dmq1); | |
fd7d2520 | 757 | } |
0f113f3e | 758 | |
fd7d2520 MC |
759 | /* compute I mod p */ |
760 | if (!BN_mod(r1, c, rsa->p, ctx)) { | |
5584f65a | 761 | BN_free(c); |
0f113f3e | 762 | goto err; |
fd7d2520 | 763 | } |
5584f65a MC |
764 | /* We MUST free c before any further use of I */ |
765 | BN_free(c); | |
0f113f3e MC |
766 | } |
767 | ||
fd7d2520 | 768 | { |
5584f65a MC |
769 | BIGNUM *dmp1 = BN_new(); |
770 | if (dmp1 == NULL) | |
771 | goto err; | |
772 | BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME); | |
773 | ||
fd7d2520 | 774 | /* compute r1^dmp1 mod p */ |
fd7d2520 MC |
775 | if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx, |
776 | rsa->_method_mod_p)) { | |
5584f65a | 777 | BN_free(dmp1); |
fd7d2520 MC |
778 | goto err; |
779 | } | |
5584f65a MC |
780 | /* We MUST free dmp1 before any further use of rsa->dmp1 */ |
781 | BN_free(dmp1); | |
fd7d2520 | 782 | } |
0f113f3e | 783 | |
f844f9eb | 784 | #ifndef FIPS_MODULE |
665d899f PY |
785 | if (ex_primes > 0) { |
786 | BIGNUM *di = BN_new(), *cc = BN_new(); | |
787 | ||
788 | if (cc == NULL || di == NULL) { | |
789 | BN_free(cc); | |
790 | BN_free(di); | |
791 | goto err; | |
792 | } | |
793 | ||
794 | for (i = 0; i < ex_primes; i++) { | |
795 | /* prepare m_i */ | |
796 | if ((m[i] = BN_CTX_get(ctx)) == NULL) { | |
797 | BN_free(cc); | |
798 | BN_free(di); | |
799 | goto err; | |
800 | } | |
801 | ||
802 | pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i); | |
803 | ||
804 | /* prepare c and d_i */ | |
805 | BN_with_flags(cc, I, BN_FLG_CONSTTIME); | |
806 | BN_with_flags(di, pinfo->d, BN_FLG_CONSTTIME); | |
807 | ||
808 | if (!BN_mod(r1, cc, pinfo->r, ctx)) { | |
809 | BN_free(cc); | |
810 | BN_free(di); | |
811 | goto err; | |
812 | } | |
813 | /* compute r1 ^ d_i mod r_i */ | |
814 | if (!rsa->meth->bn_mod_exp(m[i], r1, di, pinfo->r, ctx, pinfo->m)) { | |
815 | BN_free(cc); | |
816 | BN_free(di); | |
817 | goto err; | |
818 | } | |
819 | } | |
820 | ||
821 | BN_free(cc); | |
822 | BN_free(di); | |
823 | } | |
afb638f1 | 824 | #endif |
665d899f | 825 | |
0f113f3e MC |
826 | if (!BN_sub(r0, r0, m1)) |
827 | goto err; | |
828 | /* | |
829 | * This will help stop the size of r0 increasing, which does affect the | |
830 | * multiply if it optimised for a power of 2 size | |
831 | */ | |
832 | if (BN_is_negative(r0)) | |
833 | if (!BN_add(r0, r0, rsa->p)) | |
834 | goto err; | |
835 | ||
836 | if (!BN_mul(r1, r0, rsa->iqmp, ctx)) | |
837 | goto err; | |
838 | ||
fd7d2520 | 839 | { |
5584f65a MC |
840 | BIGNUM *pr1 = BN_new(); |
841 | if (pr1 == NULL) | |
842 | goto err; | |
843 | BN_with_flags(pr1, r1, BN_FLG_CONSTTIME); | |
844 | ||
fd7d2520 | 845 | if (!BN_mod(r0, pr1, rsa->p, ctx)) { |
5584f65a | 846 | BN_free(pr1); |
fd7d2520 MC |
847 | goto err; |
848 | } | |
5584f65a MC |
849 | /* We MUST free pr1 before any further use of r1 */ |
850 | BN_free(pr1); | |
fd7d2520 | 851 | } |
0f113f3e MC |
852 | |
853 | /* | |
854 | * If p < q it is occasionally possible for the correction of adding 'p' | |
855 | * if r0 is negative above to leave the result still negative. This can | |
856 | * break the private key operations: the following second correction | |
857 | * should *always* correct this rare occurrence. This will *never* happen | |
858 | * with OpenSSL generated keys because they ensure p > q [steve] | |
859 | */ | |
860 | if (BN_is_negative(r0)) | |
861 | if (!BN_add(r0, r0, rsa->p)) | |
862 | goto err; | |
863 | if (!BN_mul(r1, r0, rsa->q, ctx)) | |
864 | goto err; | |
865 | if (!BN_add(r0, r1, m1)) | |
866 | goto err; | |
867 | ||
f844f9eb | 868 | #ifndef FIPS_MODULE |
665d899f PY |
869 | /* add m_i to m in multi-prime case */ |
870 | if (ex_primes > 0) { | |
871 | BIGNUM *pr2 = BN_new(); | |
872 | ||
873 | if (pr2 == NULL) | |
874 | goto err; | |
875 | ||
876 | for (i = 0; i < ex_primes; i++) { | |
877 | pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i); | |
878 | if (!BN_sub(r1, m[i], r0)) { | |
879 | BN_free(pr2); | |
880 | goto err; | |
881 | } | |
882 | ||
883 | if (!BN_mul(r2, r1, pinfo->t, ctx)) { | |
884 | BN_free(pr2); | |
885 | goto err; | |
886 | } | |
887 | ||
888 | BN_with_flags(pr2, r2, BN_FLG_CONSTTIME); | |
889 | ||
890 | if (!BN_mod(r1, pr2, pinfo->r, ctx)) { | |
891 | BN_free(pr2); | |
892 | goto err; | |
893 | } | |
894 | ||
895 | if (BN_is_negative(r1)) | |
896 | if (!BN_add(r1, r1, pinfo->r)) { | |
897 | BN_free(pr2); | |
898 | goto err; | |
899 | } | |
900 | if (!BN_mul(r1, r1, pinfo->pp, ctx)) { | |
901 | BN_free(pr2); | |
902 | goto err; | |
903 | } | |
904 | if (!BN_add(r0, r0, r1)) { | |
905 | BN_free(pr2); | |
906 | goto err; | |
907 | } | |
908 | } | |
909 | BN_free(pr2); | |
910 | } | |
afb638f1 | 911 | #endif |
665d899f | 912 | |
41bfd5e7 | 913 | tail: |
0f113f3e | 914 | if (rsa->e && rsa->n) { |
41bfd5e7 AP |
915 | if (rsa->meth->bn_mod_exp == BN_mod_exp_mont) { |
916 | if (!BN_mod_exp_mont(vrfy, r0, rsa->e, rsa->n, ctx, | |
917 | rsa->_method_mod_n)) | |
918 | goto err; | |
919 | } else { | |
920 | bn_correct_top(r0); | |
921 | if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx, | |
922 | rsa->_method_mod_n)) | |
923 | goto err; | |
924 | } | |
0f113f3e MC |
925 | /* |
926 | * If 'I' was greater than (or equal to) rsa->n, the operation will | |
927 | * be equivalent to using 'I mod n'. However, the result of the | |
928 | * verify will *always* be less than 'n' so we don't check for | |
929 | * absolute equality, just congruency. | |
930 | */ | |
931 | if (!BN_sub(vrfy, vrfy, I)) | |
932 | goto err; | |
41bfd5e7 AP |
933 | if (BN_is_zero(vrfy)) { |
934 | bn_correct_top(r0); | |
935 | ret = 1; | |
936 | goto err; /* not actually error */ | |
937 | } | |
0f113f3e MC |
938 | if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) |
939 | goto err; | |
940 | if (BN_is_negative(vrfy)) | |
941 | if (!BN_add(vrfy, vrfy, rsa->n)) | |
942 | goto err; | |
943 | if (!BN_is_zero(vrfy)) { | |
944 | /* | |
945 | * 'I' and 'vrfy' aren't congruent mod n. Don't leak | |
946 | * miscalculated CRT output, just do a raw (slower) mod_exp and | |
947 | * return that instead. | |
948 | */ | |
949 | ||
5584f65a MC |
950 | BIGNUM *d = BN_new(); |
951 | if (d == NULL) | |
952 | goto err; | |
953 | BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); | |
0f113f3e | 954 | |
0f113f3e MC |
955 | if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx, |
956 | rsa->_method_mod_n)) { | |
5584f65a | 957 | BN_free(d); |
0f113f3e MC |
958 | goto err; |
959 | } | |
5584f65a MC |
960 | /* We MUST free d before any further use of rsa->d */ |
961 | BN_free(d); | |
0f113f3e MC |
962 | } |
963 | } | |
41bfd5e7 AP |
964 | /* |
965 | * It's unfortunate that we have to bn_correct_top(r0). What hopefully | |
966 | * saves the day is that correction is highly unlike, and private key | |
967 | * operations are customarily performed on blinded message. Which means | |
968 | * that attacker won't observe correlation with chosen plaintext. | |
969 | * Secondly, remaining code would still handle it in same computational | |
970 | * time and even conceal memory access pattern around corrected top. | |
971 | */ | |
972 | bn_correct_top(r0); | |
0f113f3e MC |
973 | ret = 1; |
974 | err: | |
0f113f3e | 975 | BN_CTX_end(ctx); |
8686c474 | 976 | return ret; |
0f113f3e | 977 | } |
58964a49 | 978 | |
bf160551 | 979 | static int rsa_ossl_init(RSA *rsa) |
0f113f3e MC |
980 | { |
981 | rsa->flags |= RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE; | |
8686c474 | 982 | return 1; |
0f113f3e | 983 | } |
58964a49 | 984 | |
bf160551 | 985 | static int rsa_ossl_finish(RSA *rsa) |
0f113f3e | 986 | { |
f844f9eb | 987 | #ifndef FIPS_MODULE |
665d899f PY |
988 | int i; |
989 | RSA_PRIME_INFO *pinfo; | |
990 | ||
665d899f PY |
991 | for (i = 0; i < sk_RSA_PRIME_INFO_num(rsa->prime_infos); i++) { |
992 | pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i); | |
993 | BN_MONT_CTX_free(pinfo->m); | |
994 | } | |
afb638f1 MC |
995 | #endif |
996 | ||
997 | BN_MONT_CTX_free(rsa->_method_mod_n); | |
998 | BN_MONT_CTX_free(rsa->_method_mod_p); | |
999 | BN_MONT_CTX_free(rsa->_method_mod_q); | |
8686c474 | 1000 | return 1; |
0f113f3e | 1001 | } |