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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 | |
d188a536 | 166 | CRYPTO_THREAD_write_lock(rsa->lock); |
0f113f3e MC |
167 | |
168 | if (rsa->blinding == NULL) { | |
d188a536 | 169 | rsa->blinding = RSA_setup_blinding(rsa, ctx); |
0f113f3e MC |
170 | } |
171 | ||
172 | ret = rsa->blinding; | |
173 | if (ret == NULL) | |
174 | goto err; | |
175 | ||
0b1a07c8 | 176 | if (BN_BLINDING_is_current_thread(ret)) { |
0f113f3e MC |
177 | /* rsa->blinding is ours! */ |
178 | ||
179 | *local = 1; | |
180 | } else { | |
181 | /* resort to rsa->mt_blinding instead */ | |
182 | ||
183 | /* | |
184 | * instructs rsa_blinding_convert(), rsa_blinding_invert() that the | |
185 | * BN_BLINDING is shared, meaning that accesses require locks, and | |
186 | * that the blinding factor must be stored outside the BN_BLINDING | |
187 | */ | |
188 | *local = 0; | |
189 | ||
190 | if (rsa->mt_blinding == NULL) { | |
d188a536 | 191 | rsa->mt_blinding = RSA_setup_blinding(rsa, ctx); |
0f113f3e MC |
192 | } |
193 | ret = rsa->mt_blinding; | |
194 | } | |
5679bcce | 195 | |
675f605d | 196 | err: |
d188a536 | 197 | CRYPTO_THREAD_unlock(rsa->lock); |
0f113f3e | 198 | return ret; |
800e400d | 199 | } |
5679bcce | 200 | |
e5641d7f | 201 | static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, |
0f113f3e MC |
202 | BN_CTX *ctx) |
203 | { | |
90862ab4 | 204 | if (unblind == NULL) { |
0f113f3e MC |
205 | /* |
206 | * Local blinding: store the unblinding factor in BN_BLINDING. | |
207 | */ | |
208 | return BN_BLINDING_convert_ex(f, NULL, b, ctx); | |
90862ab4 | 209 | } else { |
0f113f3e MC |
210 | /* |
211 | * Shared blinding: store the unblinding factor outside BN_BLINDING. | |
212 | */ | |
213 | int ret; | |
0b1a07c8 AG |
214 | |
215 | BN_BLINDING_lock(b); | |
0f113f3e | 216 | ret = BN_BLINDING_convert_ex(f, unblind, b, ctx); |
0b1a07c8 AG |
217 | BN_BLINDING_unlock(b); |
218 | ||
0f113f3e MC |
219 | return ret; |
220 | } | |
221 | } | |
e5641d7f BM |
222 | |
223 | static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, | |
0f113f3e MC |
224 | BN_CTX *ctx) |
225 | { | |
226 | /* | |
227 | * For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex | |
228 | * will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING | |
229 | * is shared between threads, unblind must be non-null: | |
230 | * BN_BLINDING_invert_ex will then use the local unblinding factor, and | |
231 | * will only read the modulus from BN_BLINDING. In both cases it's safe | |
232 | * to access the blinding without a lock. | |
233 | */ | |
234 | return BN_BLINDING_invert_ex(f, unblind, b, ctx); | |
235 | } | |
5679bcce | 236 | |
24cff6ce | 237 | /* signing */ |
bf160551 | 238 | static int rsa_ossl_private_encrypt(int flen, const unsigned char *from, |
0f113f3e MC |
239 | unsigned char *to, RSA *rsa, int padding) |
240 | { | |
241 | BIGNUM *f, *ret, *res; | |
582ad5d4 | 242 | int i, num = 0, r = -1; |
0f113f3e MC |
243 | unsigned char *buf = NULL; |
244 | BN_CTX *ctx = NULL; | |
245 | int local_blinding = 0; | |
246 | /* | |
247 | * Used only if the blinding structure is shared. A non-NULL unblind | |
248 | * instructs rsa_blinding_convert() and rsa_blinding_invert() to store | |
249 | * the unblinding factor outside the blinding structure. | |
250 | */ | |
251 | BIGNUM *unblind = NULL; | |
252 | BN_BLINDING *blinding = NULL; | |
253 | ||
afb638f1 | 254 | if ((ctx = BN_CTX_new_ex(rsa->libctx)) == NULL) |
0f113f3e MC |
255 | goto err; |
256 | BN_CTX_start(ctx); | |
257 | f = BN_CTX_get(ctx); | |
258 | ret = BN_CTX_get(ctx); | |
259 | num = BN_num_bytes(rsa->n); | |
260 | buf = OPENSSL_malloc(num); | |
edea42c6 | 261 | if (ret == NULL || buf == NULL) { |
9311d0c4 | 262 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
0f113f3e MC |
263 | goto err; |
264 | } | |
265 | ||
266 | switch (padding) { | |
267 | case RSA_PKCS1_PADDING: | |
268 | i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen); | |
269 | break; | |
270 | case RSA_X931_PADDING: | |
271 | i = RSA_padding_add_X931(buf, num, from, flen); | |
272 | break; | |
273 | case RSA_NO_PADDING: | |
274 | i = RSA_padding_add_none(buf, num, from, flen); | |
275 | break; | |
0f113f3e | 276 | default: |
9311d0c4 | 277 | ERR_raise(ERR_LIB_RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
0f113f3e MC |
278 | goto err; |
279 | } | |
280 | if (i <= 0) | |
281 | goto err; | |
282 | ||
283 | if (BN_bin2bn(buf, num, f) == NULL) | |
284 | goto err; | |
285 | ||
286 | if (BN_ucmp(f, rsa->n) >= 0) { | |
287 | /* usually the padding functions would catch this */ | |
9311d0c4 | 288 | ERR_raise(ERR_LIB_RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
0f113f3e MC |
289 | goto err; |
290 | } | |
291 | ||
2cc3f68c AP |
292 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) |
293 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock, | |
294 | rsa->n, ctx)) | |
295 | goto err; | |
296 | ||
0f113f3e MC |
297 | if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) { |
298 | blinding = rsa_get_blinding(rsa, &local_blinding, ctx); | |
299 | if (blinding == NULL) { | |
9311d0c4 | 300 | ERR_raise(ERR_LIB_RSA, ERR_R_INTERNAL_ERROR); |
0f113f3e MC |
301 | goto err; |
302 | } | |
303 | } | |
304 | ||
305 | if (blinding != NULL) { | |
306 | if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) { | |
9311d0c4 | 307 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
0f113f3e MC |
308 | goto err; |
309 | } | |
310 | if (!rsa_blinding_convert(blinding, f, unblind, ctx)) | |
311 | goto err; | |
312 | } | |
313 | ||
314 | if ((rsa->flags & RSA_FLAG_EXT_PKEY) || | |
665d899f | 315 | (rsa->version == RSA_ASN1_VERSION_MULTI) || |
0f113f3e MC |
316 | ((rsa->p != NULL) && |
317 | (rsa->q != NULL) && | |
318 | (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) { | |
319 | if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) | |
320 | goto err; | |
321 | } else { | |
5584f65a MC |
322 | BIGNUM *d = BN_new(); |
323 | if (d == NULL) { | |
9311d0c4 | 324 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
5584f65a | 325 | goto err; |
fd7d2520 | 326 | } |
7408f675 | 327 | if (rsa->d == NULL) { |
9311d0c4 | 328 | ERR_raise(ERR_LIB_RSA, RSA_R_MISSING_PRIVATE_KEY); |
7408f675 DO |
329 | BN_free(d); |
330 | goto err; | |
331 | } | |
5584f65a | 332 | BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); |
0f113f3e | 333 | |
0f113f3e MC |
334 | if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx, |
335 | rsa->_method_mod_n)) { | |
5584f65a | 336 | BN_free(d); |
0f113f3e MC |
337 | goto err; |
338 | } | |
5584f65a MC |
339 | /* We MUST free d before any further use of rsa->d */ |
340 | BN_free(d); | |
0f113f3e MC |
341 | } |
342 | ||
343 | if (blinding) | |
344 | if (!rsa_blinding_invert(blinding, ret, unblind, ctx)) | |
345 | goto err; | |
346 | ||
347 | if (padding == RSA_X931_PADDING) { | |
3d3cbce5 P |
348 | if (!BN_sub(f, rsa->n, ret)) |
349 | goto err; | |
0f113f3e MC |
350 | if (BN_cmp(ret, f) > 0) |
351 | res = f; | |
352 | else | |
353 | res = ret; | |
90862ab4 | 354 | } else { |
0f113f3e | 355 | res = ret; |
90862ab4 | 356 | } |
0f113f3e MC |
357 | |
358 | /* | |
582ad5d4 AP |
359 | * BN_bn2binpad puts in leading 0 bytes if the number is less than |
360 | * the length of the modulus. | |
0f113f3e | 361 | */ |
582ad5d4 | 362 | r = BN_bn2binpad(res, to, num); |
0f113f3e | 363 | err: |
ce1415ed | 364 | BN_CTX_end(ctx); |
23a1d5e9 | 365 | BN_CTX_free(ctx); |
4b45c6e5 | 366 | OPENSSL_clear_free(buf, num); |
8686c474 | 367 | return r; |
0f113f3e | 368 | } |
58964a49 | 369 | |
bf160551 | 370 | static int rsa_ossl_private_decrypt(int flen, const unsigned char *from, |
0f113f3e MC |
371 | unsigned char *to, RSA *rsa, int padding) |
372 | { | |
373 | BIGNUM *f, *ret; | |
374 | int j, num = 0, r = -1; | |
0f113f3e MC |
375 | unsigned char *buf = NULL; |
376 | BN_CTX *ctx = NULL; | |
377 | int local_blinding = 0; | |
378 | /* | |
379 | * Used only if the blinding structure is shared. A non-NULL unblind | |
380 | * instructs rsa_blinding_convert() and rsa_blinding_invert() to store | |
381 | * the unblinding factor outside the blinding structure. | |
382 | */ | |
383 | BIGNUM *unblind = NULL; | |
384 | BN_BLINDING *blinding = NULL; | |
385 | ||
afb638f1 | 386 | if ((ctx = BN_CTX_new_ex(rsa->libctx)) == NULL) |
0f113f3e MC |
387 | goto err; |
388 | BN_CTX_start(ctx); | |
389 | f = BN_CTX_get(ctx); | |
390 | ret = BN_CTX_get(ctx); | |
391 | num = BN_num_bytes(rsa->n); | |
392 | buf = OPENSSL_malloc(num); | |
edea42c6 | 393 | if (ret == NULL || buf == NULL) { |
9311d0c4 | 394 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
0f113f3e MC |
395 | goto err; |
396 | } | |
397 | ||
398 | /* | |
399 | * This check was for equality but PGP does evil things and chops off the | |
400 | * top '0' bytes | |
401 | */ | |
402 | if (flen > num) { | |
9311d0c4 | 403 | ERR_raise(ERR_LIB_RSA, RSA_R_DATA_GREATER_THAN_MOD_LEN); |
0f113f3e MC |
404 | goto err; |
405 | } | |
406 | ||
407 | /* make data into a big number */ | |
408 | if (BN_bin2bn(from, (int)flen, f) == NULL) | |
409 | goto err; | |
410 | ||
411 | if (BN_ucmp(f, rsa->n) >= 0) { | |
9311d0c4 | 412 | ERR_raise(ERR_LIB_RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
0f113f3e MC |
413 | goto err; |
414 | } | |
415 | ||
416 | if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) { | |
417 | blinding = rsa_get_blinding(rsa, &local_blinding, ctx); | |
418 | if (blinding == NULL) { | |
9311d0c4 | 419 | ERR_raise(ERR_LIB_RSA, ERR_R_INTERNAL_ERROR); |
0f113f3e MC |
420 | goto err; |
421 | } | |
422 | } | |
423 | ||
424 | if (blinding != NULL) { | |
425 | if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) { | |
9311d0c4 | 426 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
0f113f3e MC |
427 | goto err; |
428 | } | |
429 | if (!rsa_blinding_convert(blinding, f, unblind, ctx)) | |
430 | goto err; | |
431 | } | |
432 | ||
433 | /* do the decrypt */ | |
434 | if ((rsa->flags & RSA_FLAG_EXT_PKEY) || | |
665d899f | 435 | (rsa->version == RSA_ASN1_VERSION_MULTI) || |
0f113f3e MC |
436 | ((rsa->p != NULL) && |
437 | (rsa->q != NULL) && | |
438 | (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) { | |
439 | if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) | |
440 | goto err; | |
441 | } else { | |
5584f65a MC |
442 | BIGNUM *d = BN_new(); |
443 | if (d == NULL) { | |
9311d0c4 | 444 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
5584f65a | 445 | goto err; |
7408f675 DO |
446 | } |
447 | if (rsa->d == NULL) { | |
9311d0c4 | 448 | ERR_raise(ERR_LIB_RSA, RSA_R_MISSING_PRIVATE_KEY); |
7408f675 DO |
449 | BN_free(d); |
450 | goto err; | |
fd7d2520 | 451 | } |
5584f65a | 452 | BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); |
0f113f3e MC |
453 | |
454 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) | |
41bfd5e7 AP |
455 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock, |
456 | rsa->n, ctx)) { | |
5584f65a | 457 | BN_free(d); |
0f113f3e MC |
458 | goto err; |
459 | } | |
460 | if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx, | |
461 | rsa->_method_mod_n)) { | |
5584f65a | 462 | BN_free(d); |
0f113f3e MC |
463 | goto err; |
464 | } | |
5584f65a MC |
465 | /* We MUST free d before any further use of rsa->d */ |
466 | BN_free(d); | |
0f113f3e MC |
467 | } |
468 | ||
469 | if (blinding) | |
470 | if (!rsa_blinding_invert(blinding, ret, unblind, ctx)) | |
471 | goto err; | |
472 | ||
582ad5d4 | 473 | j = BN_bn2binpad(ret, buf, num); |
4a3dd629 P |
474 | if (j < 0) |
475 | goto err; | |
0f113f3e MC |
476 | |
477 | switch (padding) { | |
478 | case RSA_PKCS1_PADDING: | |
479 | r = RSA_padding_check_PKCS1_type_2(to, num, buf, j, num); | |
480 | break; | |
0f113f3e MC |
481 | case RSA_PKCS1_OAEP_PADDING: |
482 | r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0); | |
483 | break; | |
0f113f3e | 484 | case RSA_NO_PADDING: |
582ad5d4 | 485 | memcpy(to, buf, (r = j)); |
0f113f3e MC |
486 | break; |
487 | default: | |
9311d0c4 | 488 | ERR_raise(ERR_LIB_RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
0f113f3e MC |
489 | goto err; |
490 | } | |
f844f9eb | 491 | #ifndef FIPS_MODULE |
afb638f1 MC |
492 | /* |
493 | * This trick doesn't work in the FIPS provider because libcrypto manages | |
494 | * the error stack. Instead we opt not to put an error on the stack at all | |
495 | * in case of padding failure in the FIPS provider. | |
496 | */ | |
9311d0c4 | 497 | ERR_raise(ERR_LIB_RSA, RSA_R_PADDING_CHECK_FAILED); |
94dc53a3 | 498 | err_clear_last_constant_time(1 & ~constant_time_msb(r)); |
afb638f1 | 499 | #endif |
0f113f3e MC |
500 | |
501 | err: | |
ce1415ed | 502 | BN_CTX_end(ctx); |
23a1d5e9 | 503 | BN_CTX_free(ctx); |
4b45c6e5 | 504 | OPENSSL_clear_free(buf, num); |
8686c474 | 505 | return r; |
0f113f3e | 506 | } |
58964a49 | 507 | |
24cff6ce | 508 | /* signature verification */ |
bf160551 | 509 | static int rsa_ossl_public_decrypt(int flen, const unsigned char *from, |
0f113f3e MC |
510 | unsigned char *to, RSA *rsa, int padding) |
511 | { | |
512 | BIGNUM *f, *ret; | |
513 | int i, num = 0, r = -1; | |
0f113f3e MC |
514 | unsigned char *buf = NULL; |
515 | BN_CTX *ctx = NULL; | |
516 | ||
517 | if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) { | |
9311d0c4 | 518 | ERR_raise(ERR_LIB_RSA, RSA_R_MODULUS_TOO_LARGE); |
0f113f3e MC |
519 | return -1; |
520 | } | |
521 | ||
522 | if (BN_ucmp(rsa->n, rsa->e) <= 0) { | |
9311d0c4 | 523 | ERR_raise(ERR_LIB_RSA, RSA_R_BAD_E_VALUE); |
0f113f3e MC |
524 | return -1; |
525 | } | |
526 | ||
527 | /* for large moduli, enforce exponent limit */ | |
528 | if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) { | |
529 | if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) { | |
9311d0c4 | 530 | ERR_raise(ERR_LIB_RSA, RSA_R_BAD_E_VALUE); |
0f113f3e MC |
531 | return -1; |
532 | } | |
533 | } | |
534 | ||
afb638f1 | 535 | if ((ctx = BN_CTX_new_ex(rsa->libctx)) == NULL) |
0f113f3e MC |
536 | goto err; |
537 | BN_CTX_start(ctx); | |
538 | f = BN_CTX_get(ctx); | |
539 | ret = BN_CTX_get(ctx); | |
540 | num = BN_num_bytes(rsa->n); | |
541 | buf = OPENSSL_malloc(num); | |
edea42c6 | 542 | if (ret == NULL || buf == NULL) { |
9311d0c4 | 543 | ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE); |
0f113f3e MC |
544 | goto err; |
545 | } | |
546 | ||
547 | /* | |
548 | * This check was for equality but PGP does evil things and chops off the | |
549 | * top '0' bytes | |
550 | */ | |
551 | if (flen > num) { | |
9311d0c4 | 552 | ERR_raise(ERR_LIB_RSA, RSA_R_DATA_GREATER_THAN_MOD_LEN); |
0f113f3e MC |
553 | goto err; |
554 | } | |
555 | ||
556 | if (BN_bin2bn(from, flen, f) == NULL) | |
557 | goto err; | |
558 | ||
559 | if (BN_ucmp(f, rsa->n) >= 0) { | |
9311d0c4 | 560 | ERR_raise(ERR_LIB_RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
0f113f3e MC |
561 | goto err; |
562 | } | |
563 | ||
564 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) | |
41bfd5e7 AP |
565 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock, |
566 | rsa->n, ctx)) | |
0f113f3e MC |
567 | goto err; |
568 | ||
569 | if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx, | |
570 | rsa->_method_mod_n)) | |
571 | goto err; | |
572 | ||
573 | if ((padding == RSA_X931_PADDING) && ((bn_get_words(ret)[0] & 0xf) != 12)) | |
574 | if (!BN_sub(ret, rsa->n, ret)) | |
575 | goto err; | |
576 | ||
582ad5d4 | 577 | i = BN_bn2binpad(ret, buf, num); |
4a3dd629 P |
578 | if (i < 0) |
579 | goto err; | |
0f113f3e MC |
580 | |
581 | switch (padding) { | |
582 | case RSA_PKCS1_PADDING: | |
583 | r = RSA_padding_check_PKCS1_type_1(to, num, buf, i, num); | |
584 | break; | |
585 | case RSA_X931_PADDING: | |
586 | r = RSA_padding_check_X931(to, num, buf, i, num); | |
587 | break; | |
588 | case RSA_NO_PADDING: | |
582ad5d4 | 589 | memcpy(to, buf, (r = i)); |
0f113f3e MC |
590 | break; |
591 | default: | |
9311d0c4 | 592 | ERR_raise(ERR_LIB_RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
0f113f3e MC |
593 | goto err; |
594 | } | |
595 | if (r < 0) | |
9311d0c4 | 596 | ERR_raise(ERR_LIB_RSA, RSA_R_PADDING_CHECK_FAILED); |
0f113f3e MC |
597 | |
598 | err: | |
ce1415ed | 599 | BN_CTX_end(ctx); |
23a1d5e9 | 600 | BN_CTX_free(ctx); |
4b45c6e5 | 601 | OPENSSL_clear_free(buf, num); |
8686c474 | 602 | return r; |
0f113f3e | 603 | } |
58964a49 | 604 | |
bf160551 | 605 | static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) |
0f113f3e | 606 | { |
afb638f1 MC |
607 | BIGNUM *r1, *m1, *vrfy; |
608 | int ret = 0, smooth = 0; | |
f844f9eb | 609 | #ifndef FIPS_MODULE |
afb638f1 MC |
610 | BIGNUM *r2, *m[RSA_MAX_PRIME_NUM - 2]; |
611 | int i, ex_primes = 0; | |
665d899f | 612 | RSA_PRIME_INFO *pinfo; |
afb638f1 | 613 | #endif |
0f113f3e | 614 | |
c804d23d PC |
615 | BN_CTX_start(ctx); |
616 | ||
0f113f3e | 617 | r1 = BN_CTX_get(ctx); |
f844f9eb | 618 | #ifndef FIPS_MODULE |
665d899f | 619 | r2 = BN_CTX_get(ctx); |
afb638f1 | 620 | #endif |
0f113f3e MC |
621 | m1 = BN_CTX_get(ctx); |
622 | vrfy = BN_CTX_get(ctx); | |
5625567f BE |
623 | if (vrfy == NULL) |
624 | goto err; | |
0f113f3e | 625 | |
f844f9eb | 626 | #ifndef FIPS_MODULE |
665d899f | 627 | if (rsa->version == RSA_ASN1_VERSION_MULTI |
a1471588 BE |
628 | && ((ex_primes = sk_RSA_PRIME_INFO_num(rsa->prime_infos)) <= 0 |
629 | || ex_primes > RSA_MAX_PRIME_NUM - 2)) | |
665d899f | 630 | goto err; |
afb638f1 | 631 | #endif |
665d899f | 632 | |
41bfd5e7 AP |
633 | if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) { |
634 | BIGNUM *factor = BN_new(); | |
635 | ||
636 | if (factor == NULL) | |
637 | goto err; | |
0f113f3e MC |
638 | |
639 | /* | |
0d4fb843 | 640 | * Make sure BN_mod_inverse in Montgomery initialization uses the |
5584f65a | 641 | * BN_FLG_CONSTTIME flag |
0f113f3e | 642 | */ |
41bfd5e7 AP |
643 | if (!(BN_with_flags(factor, rsa->p, BN_FLG_CONSTTIME), |
644 | BN_MONT_CTX_set_locked(&rsa->_method_mod_p, rsa->lock, | |
645 | factor, ctx)) | |
646 | || !(BN_with_flags(factor, rsa->q, BN_FLG_CONSTTIME), | |
647 | BN_MONT_CTX_set_locked(&rsa->_method_mod_q, rsa->lock, | |
648 | factor, ctx))) { | |
649 | BN_free(factor); | |
5584f65a | 650 | goto err; |
0f113f3e | 651 | } |
f844f9eb | 652 | #ifndef FIPS_MODULE |
41bfd5e7 AP |
653 | for (i = 0; i < ex_primes; i++) { |
654 | pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i); | |
655 | BN_with_flags(factor, pinfo->r, BN_FLG_CONSTTIME); | |
656 | if (!BN_MONT_CTX_set_locked(&pinfo->m, rsa->lock, factor, ctx)) { | |
657 | BN_free(factor); | |
0f113f3e MC |
658 | goto err; |
659 | } | |
660 | } | |
afb638f1 | 661 | #endif |
fd7d2520 | 662 | /* |
41bfd5e7 | 663 | * We MUST free |factor| before any further use of the prime factors |
fd7d2520 | 664 | */ |
41bfd5e7 AP |
665 | BN_free(factor); |
666 | ||
afb638f1 | 667 | smooth = (rsa->meth->bn_mod_exp == BN_mod_exp_mont) |
f844f9eb | 668 | #ifndef FIPS_MODULE |
afb638f1 MC |
669 | && (ex_primes == 0) |
670 | #endif | |
41bfd5e7 | 671 | && (BN_num_bits(rsa->q) == BN_num_bits(rsa->p)); |
0f113f3e MC |
672 | } |
673 | ||
674 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) | |
41bfd5e7 AP |
675 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock, |
676 | rsa->n, ctx)) | |
677 | goto err; | |
678 | ||
679 | if (smooth) { | |
680 | /* | |
681 | * Conversion from Montgomery domain, a.k.a. Montgomery reduction, | |
682 | * accepts values in [0-m*2^w) range. w is m's bit width rounded up | |
683 | * to limb width. So that at the very least if |I| is fully reduced, | |
684 | * i.e. less than p*q, we can count on from-to round to perform | |
685 | * below modulo operations on |I|. Unlike BN_mod it's constant time. | |
686 | */ | |
687 | if (/* m1 = I moq q */ | |
688 | !bn_from_mont_fixed_top(m1, I, rsa->_method_mod_q, ctx) | |
689 | || !bn_to_mont_fixed_top(m1, m1, rsa->_method_mod_q, ctx) | |
690 | /* m1 = m1^dmq1 mod q */ | |
691 | || !BN_mod_exp_mont_consttime(m1, m1, rsa->dmq1, rsa->q, ctx, | |
692 | rsa->_method_mod_q) | |
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) | |
696 | /* r1 = r1^dmp1 mod p */ | |
697 | || !BN_mod_exp_mont_consttime(r1, r1, rsa->dmp1, rsa->p, ctx, | |
698 | rsa->_method_mod_p) | |
699 | /* r1 = (r1 - m1) mod p */ | |
700 | /* | |
701 | * bn_mod_sub_fixed_top is not regular modular subtraction, | |
702 | * it can tolerate subtrahend to be larger than modulus, but | |
703 | * not bit-wise wider. This makes up for uncommon q>p case, | |
704 | * when |m1| can be larger than |rsa->p|. | |
705 | */ | |
706 | || !bn_mod_sub_fixed_top(r1, r1, m1, rsa->p) | |
707 | ||
d1c008f6 | 708 | /* r1 = r1 * iqmp mod p */ |
41bfd5e7 AP |
709 | || !bn_to_mont_fixed_top(r1, r1, rsa->_method_mod_p, ctx) |
710 | || !bn_mul_mont_fixed_top(r1, r1, rsa->iqmp, rsa->_method_mod_p, | |
711 | ctx) | |
d1c008f6 | 712 | /* r0 = r1 * q + m1 */ |
41bfd5e7 AP |
713 | || !bn_mul_fixed_top(r0, r1, rsa->q, ctx) |
714 | || !bn_mod_add_fixed_top(r0, r0, m1, rsa->n)) | |
0f113f3e MC |
715 | goto err; |
716 | ||
41bfd5e7 AP |
717 | goto tail; |
718 | } | |
719 | ||
0f113f3e | 720 | /* compute I mod q */ |
fd7d2520 | 721 | { |
5584f65a MC |
722 | BIGNUM *c = BN_new(); |
723 | if (c == NULL) | |
724 | goto err; | |
725 | BN_with_flags(c, I, BN_FLG_CONSTTIME); | |
726 | ||
fd7d2520 | 727 | if (!BN_mod(r1, c, rsa->q, ctx)) { |
5584f65a | 728 | BN_free(c); |
0f113f3e | 729 | goto err; |
fd7d2520 | 730 | } |
0f113f3e | 731 | |
fd7d2520 | 732 | { |
5584f65a MC |
733 | BIGNUM *dmq1 = BN_new(); |
734 | if (dmq1 == NULL) { | |
735 | BN_free(c); | |
736 | goto err; | |
fd7d2520 | 737 | } |
5584f65a MC |
738 | BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME); |
739 | ||
740 | /* compute r1^dmq1 mod q */ | |
fd7d2520 | 741 | if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx, |
41bfd5e7 | 742 | rsa->_method_mod_q)) { |
5584f65a MC |
743 | BN_free(c); |
744 | BN_free(dmq1); | |
fd7d2520 MC |
745 | goto err; |
746 | } | |
5584f65a MC |
747 | /* We MUST free dmq1 before any further use of rsa->dmq1 */ |
748 | BN_free(dmq1); | |
fd7d2520 | 749 | } |
0f113f3e | 750 | |
fd7d2520 MC |
751 | /* compute I mod p */ |
752 | if (!BN_mod(r1, c, rsa->p, ctx)) { | |
5584f65a | 753 | BN_free(c); |
0f113f3e | 754 | goto err; |
fd7d2520 | 755 | } |
5584f65a MC |
756 | /* We MUST free c before any further use of I */ |
757 | BN_free(c); | |
0f113f3e MC |
758 | } |
759 | ||
fd7d2520 | 760 | { |
5584f65a MC |
761 | BIGNUM *dmp1 = BN_new(); |
762 | if (dmp1 == NULL) | |
763 | goto err; | |
764 | BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME); | |
765 | ||
fd7d2520 | 766 | /* compute r1^dmp1 mod p */ |
fd7d2520 MC |
767 | if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx, |
768 | rsa->_method_mod_p)) { | |
5584f65a | 769 | BN_free(dmp1); |
fd7d2520 MC |
770 | goto err; |
771 | } | |
5584f65a MC |
772 | /* We MUST free dmp1 before any further use of rsa->dmp1 */ |
773 | BN_free(dmp1); | |
fd7d2520 | 774 | } |
0f113f3e | 775 | |
f844f9eb | 776 | #ifndef FIPS_MODULE |
665d899f PY |
777 | /* |
778 | * calculate m_i in multi-prime case | |
779 | * | |
780 | * TODO: | |
781 | * 1. squash the following two loops and calculate |m_i| there. | |
782 | * 2. remove cc and reuse |c|. | |
783 | * 3. remove |dmq1| and |dmp1| in previous block and use |di|. | |
784 | * | |
785 | * If these things are done, the code will be more readable. | |
786 | */ | |
787 | if (ex_primes > 0) { | |
788 | BIGNUM *di = BN_new(), *cc = BN_new(); | |
789 | ||
790 | if (cc == NULL || di == NULL) { | |
791 | BN_free(cc); | |
792 | BN_free(di); | |
793 | goto err; | |
794 | } | |
795 | ||
796 | for (i = 0; i < ex_primes; i++) { | |
797 | /* prepare m_i */ | |
798 | if ((m[i] = BN_CTX_get(ctx)) == NULL) { | |
799 | BN_free(cc); | |
800 | BN_free(di); | |
801 | goto err; | |
802 | } | |
803 | ||
804 | pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i); | |
805 | ||
806 | /* prepare c and d_i */ | |
807 | BN_with_flags(cc, I, BN_FLG_CONSTTIME); | |
808 | BN_with_flags(di, pinfo->d, BN_FLG_CONSTTIME); | |
809 | ||
810 | if (!BN_mod(r1, cc, pinfo->r, ctx)) { | |
811 | BN_free(cc); | |
812 | BN_free(di); | |
813 | goto err; | |
814 | } | |
815 | /* compute r1 ^ d_i mod r_i */ | |
816 | if (!rsa->meth->bn_mod_exp(m[i], r1, di, pinfo->r, ctx, pinfo->m)) { | |
817 | BN_free(cc); | |
818 | BN_free(di); | |
819 | goto err; | |
820 | } | |
821 | } | |
822 | ||
823 | BN_free(cc); | |
824 | BN_free(di); | |
825 | } | |
afb638f1 | 826 | #endif |
665d899f | 827 | |
0f113f3e MC |
828 | if (!BN_sub(r0, r0, m1)) |
829 | goto err; | |
830 | /* | |
831 | * This will help stop the size of r0 increasing, which does affect the | |
832 | * multiply if it optimised for a power of 2 size | |
833 | */ | |
834 | if (BN_is_negative(r0)) | |
835 | if (!BN_add(r0, r0, rsa->p)) | |
836 | goto err; | |
837 | ||
838 | if (!BN_mul(r1, r0, rsa->iqmp, ctx)) | |
839 | goto err; | |
840 | ||
fd7d2520 | 841 | { |
5584f65a MC |
842 | BIGNUM *pr1 = BN_new(); |
843 | if (pr1 == NULL) | |
844 | goto err; | |
845 | BN_with_flags(pr1, r1, BN_FLG_CONSTTIME); | |
846 | ||
fd7d2520 | 847 | if (!BN_mod(r0, pr1, rsa->p, ctx)) { |
5584f65a | 848 | BN_free(pr1); |
fd7d2520 MC |
849 | goto err; |
850 | } | |
5584f65a MC |
851 | /* We MUST free pr1 before any further use of r1 */ |
852 | BN_free(pr1); | |
fd7d2520 | 853 | } |
0f113f3e MC |
854 | |
855 | /* | |
856 | * If p < q it is occasionally possible for the correction of adding 'p' | |
857 | * if r0 is negative above to leave the result still negative. This can | |
858 | * break the private key operations: the following second correction | |
859 | * should *always* correct this rare occurrence. This will *never* happen | |
860 | * with OpenSSL generated keys because they ensure p > q [steve] | |
861 | */ | |
862 | if (BN_is_negative(r0)) | |
863 | if (!BN_add(r0, r0, rsa->p)) | |
864 | goto err; | |
865 | if (!BN_mul(r1, r0, rsa->q, ctx)) | |
866 | goto err; | |
867 | if (!BN_add(r0, r1, m1)) | |
868 | goto err; | |
869 | ||
f844f9eb | 870 | #ifndef FIPS_MODULE |
665d899f PY |
871 | /* add m_i to m in multi-prime case */ |
872 | if (ex_primes > 0) { | |
873 | BIGNUM *pr2 = BN_new(); | |
874 | ||
875 | if (pr2 == NULL) | |
876 | goto err; | |
877 | ||
878 | for (i = 0; i < ex_primes; i++) { | |
879 | pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i); | |
880 | if (!BN_sub(r1, m[i], r0)) { | |
881 | BN_free(pr2); | |
882 | goto err; | |
883 | } | |
884 | ||
885 | if (!BN_mul(r2, r1, pinfo->t, ctx)) { | |
886 | BN_free(pr2); | |
887 | goto err; | |
888 | } | |
889 | ||
890 | BN_with_flags(pr2, r2, BN_FLG_CONSTTIME); | |
891 | ||
892 | if (!BN_mod(r1, pr2, pinfo->r, ctx)) { | |
893 | BN_free(pr2); | |
894 | goto err; | |
895 | } | |
896 | ||
897 | if (BN_is_negative(r1)) | |
898 | if (!BN_add(r1, r1, pinfo->r)) { | |
899 | BN_free(pr2); | |
900 | goto err; | |
901 | } | |
902 | if (!BN_mul(r1, r1, pinfo->pp, ctx)) { | |
903 | BN_free(pr2); | |
904 | goto err; | |
905 | } | |
906 | if (!BN_add(r0, r0, r1)) { | |
907 | BN_free(pr2); | |
908 | goto err; | |
909 | } | |
910 | } | |
911 | BN_free(pr2); | |
912 | } | |
afb638f1 | 913 | #endif |
665d899f | 914 | |
41bfd5e7 | 915 | tail: |
0f113f3e | 916 | if (rsa->e && rsa->n) { |
41bfd5e7 AP |
917 | if (rsa->meth->bn_mod_exp == BN_mod_exp_mont) { |
918 | if (!BN_mod_exp_mont(vrfy, r0, rsa->e, rsa->n, ctx, | |
919 | rsa->_method_mod_n)) | |
920 | goto err; | |
921 | } else { | |
922 | bn_correct_top(r0); | |
923 | if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx, | |
924 | rsa->_method_mod_n)) | |
925 | goto err; | |
926 | } | |
0f113f3e MC |
927 | /* |
928 | * If 'I' was greater than (or equal to) rsa->n, the operation will | |
929 | * be equivalent to using 'I mod n'. However, the result of the | |
930 | * verify will *always* be less than 'n' so we don't check for | |
931 | * absolute equality, just congruency. | |
932 | */ | |
933 | if (!BN_sub(vrfy, vrfy, I)) | |
934 | goto err; | |
41bfd5e7 AP |
935 | if (BN_is_zero(vrfy)) { |
936 | bn_correct_top(r0); | |
937 | ret = 1; | |
938 | goto err; /* not actually error */ | |
939 | } | |
0f113f3e MC |
940 | if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) |
941 | goto err; | |
942 | if (BN_is_negative(vrfy)) | |
943 | if (!BN_add(vrfy, vrfy, rsa->n)) | |
944 | goto err; | |
945 | if (!BN_is_zero(vrfy)) { | |
946 | /* | |
947 | * 'I' and 'vrfy' aren't congruent mod n. Don't leak | |
948 | * miscalculated CRT output, just do a raw (slower) mod_exp and | |
949 | * return that instead. | |
950 | */ | |
951 | ||
5584f65a MC |
952 | BIGNUM *d = BN_new(); |
953 | if (d == NULL) | |
954 | goto err; | |
955 | BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); | |
0f113f3e | 956 | |
0f113f3e MC |
957 | if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx, |
958 | rsa->_method_mod_n)) { | |
5584f65a | 959 | BN_free(d); |
0f113f3e MC |
960 | goto err; |
961 | } | |
5584f65a MC |
962 | /* We MUST free d before any further use of rsa->d */ |
963 | BN_free(d); | |
0f113f3e MC |
964 | } |
965 | } | |
41bfd5e7 AP |
966 | /* |
967 | * It's unfortunate that we have to bn_correct_top(r0). What hopefully | |
968 | * saves the day is that correction is highly unlike, and private key | |
969 | * operations are customarily performed on blinded message. Which means | |
970 | * that attacker won't observe correlation with chosen plaintext. | |
971 | * Secondly, remaining code would still handle it in same computational | |
972 | * time and even conceal memory access pattern around corrected top. | |
973 | */ | |
974 | bn_correct_top(r0); | |
0f113f3e MC |
975 | ret = 1; |
976 | err: | |
0f113f3e | 977 | BN_CTX_end(ctx); |
8686c474 | 978 | return ret; |
0f113f3e | 979 | } |
58964a49 | 980 | |
bf160551 | 981 | static int rsa_ossl_init(RSA *rsa) |
0f113f3e MC |
982 | { |
983 | rsa->flags |= RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE; | |
8686c474 | 984 | return 1; |
0f113f3e | 985 | } |
58964a49 | 986 | |
bf160551 | 987 | static int rsa_ossl_finish(RSA *rsa) |
0f113f3e | 988 | { |
f844f9eb | 989 | #ifndef FIPS_MODULE |
665d899f PY |
990 | int i; |
991 | RSA_PRIME_INFO *pinfo; | |
992 | ||
665d899f PY |
993 | for (i = 0; i < sk_RSA_PRIME_INFO_num(rsa->prime_infos); i++) { |
994 | pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i); | |
995 | BN_MONT_CTX_free(pinfo->m); | |
996 | } | |
afb638f1 MC |
997 | #endif |
998 | ||
999 | BN_MONT_CTX_free(rsa->_method_mod_n); | |
1000 | BN_MONT_CTX_free(rsa->_method_mod_p); | |
1001 | BN_MONT_CTX_free(rsa->_method_mod_q); | |
8686c474 | 1002 | return 1; |
0f113f3e | 1003 | } |