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 <limits.h>
60 #include <string.h>
61
62 #include <openssl/bn.h>
63 #include <openssl/engine.h>
64 #include <openssl/err.h>
65 #include <openssl/ex_data.h>
66 #include <openssl/mem.h>
67 #include <openssl/obj.h>
68 #include <openssl/thread.h>
69
70 #include "internal.h"
71 #include "../internal.h"
72
73
74 static CRYPTO_EX_DATA_CLASS g_ex_data_class = CRYPTO_EX_DATA_CLASS_INIT;
75
RSA_new(void)76 RSA *RSA_new(void) { return RSA_new_method(NULL); }
77
RSA_new_method(const ENGINE * engine)78 RSA *RSA_new_method(const ENGINE *engine) {
79 RSA *rsa = (RSA *)OPENSSL_malloc(sizeof(RSA));
80 if (rsa == NULL) {
81 OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
82 return NULL;
83 }
84
85 memset(rsa, 0, sizeof(RSA));
86
87 if (engine) {
88 rsa->meth = ENGINE_get_RSA_method(engine);
89 }
90
91 if (rsa->meth == NULL) {
92 rsa->meth = (RSA_METHOD*) &RSA_default_method;
93 }
94 METHOD_ref(rsa->meth);
95
96 rsa->references = 1;
97 rsa->flags = rsa->meth->flags;
98 CRYPTO_MUTEX_init(&rsa->lock);
99 CRYPTO_new_ex_data(&rsa->ex_data);
100
101 if (rsa->meth->init && !rsa->meth->init(rsa)) {
102 CRYPTO_free_ex_data(&g_ex_data_class, rsa, &rsa->ex_data);
103 CRYPTO_MUTEX_cleanup(&rsa->lock);
104 METHOD_unref(rsa->meth);
105 OPENSSL_free(rsa);
106 return NULL;
107 }
108
109 return rsa;
110 }
111
RSA_additional_prime_free(RSA_additional_prime * ap)112 void RSA_additional_prime_free(RSA_additional_prime *ap) {
113 if (ap == NULL) {
114 return;
115 }
116
117 BN_clear_free(ap->prime);
118 BN_clear_free(ap->exp);
119 BN_clear_free(ap->coeff);
120 BN_clear_free(ap->r);
121 BN_MONT_CTX_free(ap->mont);
122 OPENSSL_free(ap);
123 }
124
RSA_free(RSA * rsa)125 void RSA_free(RSA *rsa) {
126 unsigned u;
127
128 if (rsa == NULL) {
129 return;
130 }
131
132 if (!CRYPTO_refcount_dec_and_test_zero(&rsa->references)) {
133 return;
134 }
135
136 if (rsa->meth->finish) {
137 rsa->meth->finish(rsa);
138 }
139 METHOD_unref(rsa->meth);
140
141 CRYPTO_free_ex_data(&g_ex_data_class, rsa, &rsa->ex_data);
142
143 BN_clear_free(rsa->n);
144 BN_clear_free(rsa->e);
145 BN_clear_free(rsa->d);
146 BN_clear_free(rsa->p);
147 BN_clear_free(rsa->q);
148 BN_clear_free(rsa->dmp1);
149 BN_clear_free(rsa->dmq1);
150 BN_clear_free(rsa->iqmp);
151 BN_MONT_CTX_free(rsa->mont_n);
152 BN_MONT_CTX_free(rsa->mont_p);
153 BN_MONT_CTX_free(rsa->mont_q);
154 for (u = 0; u < rsa->num_blindings; u++) {
155 BN_BLINDING_free(rsa->blindings[u]);
156 }
157 OPENSSL_free(rsa->blindings);
158 OPENSSL_free(rsa->blindings_inuse);
159 if (rsa->additional_primes != NULL) {
160 sk_RSA_additional_prime_pop_free(rsa->additional_primes,
161 RSA_additional_prime_free);
162 }
163 CRYPTO_MUTEX_cleanup(&rsa->lock);
164 OPENSSL_free(rsa);
165 }
166
RSA_up_ref(RSA * rsa)167 int RSA_up_ref(RSA *rsa) {
168 CRYPTO_refcount_inc(&rsa->references);
169 return 1;
170 }
171
RSA_generate_key_ex(RSA * rsa,int bits,BIGNUM * e_value,BN_GENCB * cb)172 int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) {
173 if (rsa->meth->keygen) {
174 return rsa->meth->keygen(rsa, bits, e_value, cb);
175 }
176
177 return rsa_default_keygen(rsa, bits, e_value, cb);
178 }
179
RSA_generate_multi_prime_key(RSA * rsa,int bits,int num_primes,BIGNUM * e_value,BN_GENCB * cb)180 int RSA_generate_multi_prime_key(RSA *rsa, int bits, int num_primes,
181 BIGNUM *e_value, BN_GENCB *cb) {
182 if (rsa->meth->multi_prime_keygen) {
183 return rsa->meth->multi_prime_keygen(rsa, bits, num_primes, e_value, cb);
184 }
185
186 return rsa_default_multi_prime_keygen(rsa, bits, num_primes, e_value, cb);
187 }
188
RSA_encrypt(RSA * rsa,size_t * out_len,uint8_t * out,size_t max_out,const uint8_t * in,size_t in_len,int padding)189 int RSA_encrypt(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
190 const uint8_t *in, size_t in_len, int padding) {
191 if (rsa->meth->encrypt) {
192 return rsa->meth->encrypt(rsa, out_len, out, max_out, in, in_len, padding);
193 }
194
195 return rsa_default_encrypt(rsa, out_len, out, max_out, in, in_len, padding);
196 }
197
RSA_public_encrypt(size_t flen,const uint8_t * from,uint8_t * to,RSA * rsa,int padding)198 int RSA_public_encrypt(size_t flen, const uint8_t *from, uint8_t *to, RSA *rsa,
199 int padding) {
200 size_t out_len;
201
202 if (!RSA_encrypt(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
203 return -1;
204 }
205
206 if (out_len > INT_MAX) {
207 OPENSSL_PUT_ERROR(RSA, ERR_R_OVERFLOW);
208 return -1;
209 }
210 return out_len;
211 }
212
RSA_sign_raw(RSA * rsa,size_t * out_len,uint8_t * out,size_t max_out,const uint8_t * in,size_t in_len,int padding)213 int RSA_sign_raw(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
214 const uint8_t *in, size_t in_len, int padding) {
215 if (rsa->meth->sign_raw) {
216 return rsa->meth->sign_raw(rsa, out_len, out, max_out, in, in_len, padding);
217 }
218
219 return rsa_default_sign_raw(rsa, out_len, out, max_out, in, in_len, padding);
220 }
221
RSA_private_encrypt(size_t flen,const uint8_t * from,uint8_t * to,RSA * rsa,int padding)222 int RSA_private_encrypt(size_t flen, const uint8_t *from, uint8_t *to, RSA *rsa,
223 int padding) {
224 size_t out_len;
225
226 if (!RSA_sign_raw(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
227 return -1;
228 }
229
230 if (out_len > INT_MAX) {
231 OPENSSL_PUT_ERROR(RSA, ERR_R_OVERFLOW);
232 return -1;
233 }
234 return out_len;
235 }
236
RSA_decrypt(RSA * rsa,size_t * out_len,uint8_t * out,size_t max_out,const uint8_t * in,size_t in_len,int padding)237 int RSA_decrypt(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
238 const uint8_t *in, size_t in_len, int padding) {
239 if (rsa->meth->decrypt) {
240 return rsa->meth->decrypt(rsa, out_len, out, max_out, in, in_len, padding);
241 }
242
243 return rsa_default_decrypt(rsa, out_len, out, max_out, in, in_len, padding);
244 }
245
RSA_private_decrypt(size_t flen,const uint8_t * from,uint8_t * to,RSA * rsa,int padding)246 int RSA_private_decrypt(size_t flen, const uint8_t *from, uint8_t *to, RSA *rsa,
247 int padding) {
248 size_t out_len;
249
250 if (!RSA_decrypt(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
251 return -1;
252 }
253
254 if (out_len > INT_MAX) {
255 OPENSSL_PUT_ERROR(RSA, ERR_R_OVERFLOW);
256 return -1;
257 }
258 return out_len;
259 }
260
RSA_verify_raw(RSA * rsa,size_t * out_len,uint8_t * out,size_t max_out,const uint8_t * in,size_t in_len,int padding)261 int RSA_verify_raw(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
262 const uint8_t *in, size_t in_len, int padding) {
263 if (rsa->meth->verify_raw) {
264 return rsa->meth->verify_raw(rsa, out_len, out, max_out, in, in_len, padding);
265 }
266
267 return rsa_default_verify_raw(rsa, out_len, out, max_out, in, in_len,
268 padding);
269 }
270
RSA_public_decrypt(size_t flen,const uint8_t * from,uint8_t * to,RSA * rsa,int padding)271 int RSA_public_decrypt(size_t flen, const uint8_t *from, uint8_t *to, RSA *rsa,
272 int padding) {
273 size_t out_len;
274
275 if (!RSA_verify_raw(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
276 return -1;
277 }
278
279 if (out_len > INT_MAX) {
280 OPENSSL_PUT_ERROR(RSA, ERR_R_OVERFLOW);
281 return -1;
282 }
283 return out_len;
284 }
285
RSA_size(const RSA * rsa)286 unsigned RSA_size(const RSA *rsa) {
287 if (rsa->meth->size) {
288 return rsa->meth->size(rsa);
289 }
290
291 return rsa_default_size(rsa);
292 }
293
RSA_is_opaque(const RSA * rsa)294 int RSA_is_opaque(const RSA *rsa) {
295 return rsa->meth && (rsa->meth->flags & RSA_FLAG_OPAQUE);
296 }
297
RSA_supports_digest(const RSA * rsa,const EVP_MD * md)298 int RSA_supports_digest(const RSA *rsa, const EVP_MD *md) {
299 if (rsa->meth && rsa->meth->supports_digest) {
300 return rsa->meth->supports_digest(rsa, md);
301 }
302 return 1;
303 }
304
RSA_get_ex_new_index(long argl,void * argp,CRYPTO_EX_unused * unused,CRYPTO_EX_dup * dup_func,CRYPTO_EX_free * free_func)305 int RSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_unused *unused,
306 CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) {
307 int index;
308 if (!CRYPTO_get_ex_new_index(&g_ex_data_class, &index, argl, argp, dup_func,
309 free_func)) {
310 return -1;
311 }
312 return index;
313 }
314
RSA_set_ex_data(RSA * d,int idx,void * arg)315 int RSA_set_ex_data(RSA *d, int idx, void *arg) {
316 return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
317 }
318
RSA_get_ex_data(const RSA * d,int idx)319 void *RSA_get_ex_data(const RSA *d, int idx) {
320 return CRYPTO_get_ex_data(&d->ex_data, idx);
321 }
322
323 /* SSL_SIG_LENGTH is the size of an SSL/TLS (prior to TLS 1.2) signature: it's
324 * the length of an MD5 and SHA1 hash. */
325 static const unsigned SSL_SIG_LENGTH = 36;
326
327 /* pkcs1_sig_prefix contains the ASN.1, DER encoded prefix for a hash that is
328 * to be signed with PKCS#1. */
329 struct pkcs1_sig_prefix {
330 /* nid identifies the hash function. */
331 int nid;
332 /* len is the number of bytes of |bytes| which are valid. */
333 uint8_t len;
334 /* bytes contains the DER bytes. */
335 uint8_t bytes[19];
336 };
337
338 /* kPKCS1SigPrefixes contains the ASN.1 prefixes for PKCS#1 signatures with
339 * different hash functions. */
340 static const struct pkcs1_sig_prefix kPKCS1SigPrefixes[] = {
341 {
342 NID_md5,
343 18,
344 {0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d,
345 0x02, 0x05, 0x05, 0x00, 0x04, 0x10},
346 },
347 {
348 NID_sha1,
349 15,
350 {0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05,
351 0x00, 0x04, 0x14},
352 },
353 {
354 NID_sha224,
355 19,
356 {0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
357 0x04, 0x02, 0x04, 0x05, 0x00, 0x04, 0x1c},
358 },
359 {
360 NID_sha256,
361 19,
362 {0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
363 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20},
364 },
365 {
366 NID_sha384,
367 19,
368 {0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
369 0x04, 0x02, 0x02, 0x05, 0x00, 0x04, 0x30},
370 },
371 {
372 NID_sha512,
373 19,
374 {0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
375 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40},
376 },
377 {
378 NID_undef, 0, {0},
379 },
380 };
381
RSA_add_pkcs1_prefix(uint8_t ** out_msg,size_t * out_msg_len,int * is_alloced,int hash_nid,const uint8_t * msg,size_t msg_len)382 int RSA_add_pkcs1_prefix(uint8_t **out_msg, size_t *out_msg_len,
383 int *is_alloced, int hash_nid, const uint8_t *msg,
384 size_t msg_len) {
385 unsigned i;
386
387 if (hash_nid == NID_md5_sha1) {
388 /* Special case: SSL signature, just check the length. */
389 if (msg_len != SSL_SIG_LENGTH) {
390 OPENSSL_PUT_ERROR(RSA, RSA_R_INVALID_MESSAGE_LENGTH);
391 return 0;
392 }
393
394 *out_msg = (uint8_t*) msg;
395 *out_msg_len = SSL_SIG_LENGTH;
396 *is_alloced = 0;
397 return 1;
398 }
399
400 for (i = 0; kPKCS1SigPrefixes[i].nid != NID_undef; i++) {
401 const struct pkcs1_sig_prefix *sig_prefix = &kPKCS1SigPrefixes[i];
402 if (sig_prefix->nid != hash_nid) {
403 continue;
404 }
405
406 const uint8_t* prefix = sig_prefix->bytes;
407 unsigned prefix_len = sig_prefix->len;
408 unsigned signed_msg_len;
409 uint8_t *signed_msg;
410
411 signed_msg_len = prefix_len + msg_len;
412 if (signed_msg_len < prefix_len) {
413 OPENSSL_PUT_ERROR(RSA, RSA_R_TOO_LONG);
414 return 0;
415 }
416
417 signed_msg = OPENSSL_malloc(signed_msg_len);
418 if (!signed_msg) {
419 OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
420 return 0;
421 }
422
423 memcpy(signed_msg, prefix, prefix_len);
424 memcpy(signed_msg + prefix_len, msg, msg_len);
425
426 *out_msg = signed_msg;
427 *out_msg_len = signed_msg_len;
428 *is_alloced = 1;
429
430 return 1;
431 }
432
433 OPENSSL_PUT_ERROR(RSA, RSA_R_UNKNOWN_ALGORITHM_TYPE);
434 return 0;
435 }
436
RSA_sign(int hash_nid,const uint8_t * in,unsigned in_len,uint8_t * out,unsigned * out_len,RSA * rsa)437 int RSA_sign(int hash_nid, const uint8_t *in, unsigned in_len, uint8_t *out,
438 unsigned *out_len, RSA *rsa) {
439 const unsigned rsa_size = RSA_size(rsa);
440 int ret = 0;
441 uint8_t *signed_msg;
442 size_t signed_msg_len;
443 int signed_msg_is_alloced = 0;
444 size_t size_t_out_len;
445
446 if (rsa->meth->sign) {
447 return rsa->meth->sign(hash_nid, in, in_len, out, out_len, rsa);
448 }
449
450 if (!RSA_add_pkcs1_prefix(&signed_msg, &signed_msg_len,
451 &signed_msg_is_alloced, hash_nid, in, in_len)) {
452 return 0;
453 }
454
455 if (rsa_size < RSA_PKCS1_PADDING_SIZE ||
456 signed_msg_len > rsa_size - RSA_PKCS1_PADDING_SIZE) {
457 OPENSSL_PUT_ERROR(RSA, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
458 goto finish;
459 }
460
461 if (RSA_sign_raw(rsa, &size_t_out_len, out, rsa_size, signed_msg,
462 signed_msg_len, RSA_PKCS1_PADDING)) {
463 *out_len = size_t_out_len;
464 ret = 1;
465 }
466
467 finish:
468 if (signed_msg_is_alloced) {
469 OPENSSL_free(signed_msg);
470 }
471 return ret;
472 }
473
RSA_verify(int hash_nid,const uint8_t * msg,size_t msg_len,const uint8_t * sig,size_t sig_len,RSA * rsa)474 int RSA_verify(int hash_nid, const uint8_t *msg, size_t msg_len,
475 const uint8_t *sig, size_t sig_len, RSA *rsa) {
476 const size_t rsa_size = RSA_size(rsa);
477 uint8_t *buf = NULL;
478 int ret = 0;
479 uint8_t *signed_msg = NULL;
480 size_t signed_msg_len, len;
481 int signed_msg_is_alloced = 0;
482
483 if (rsa->meth->verify) {
484 return rsa->meth->verify(hash_nid, msg, msg_len, sig, sig_len, rsa);
485 }
486
487 if (sig_len != rsa_size) {
488 OPENSSL_PUT_ERROR(RSA, RSA_R_WRONG_SIGNATURE_LENGTH);
489 return 0;
490 }
491
492 if (hash_nid == NID_md5_sha1 && msg_len != SSL_SIG_LENGTH) {
493 OPENSSL_PUT_ERROR(RSA, RSA_R_INVALID_MESSAGE_LENGTH);
494 return 0;
495 }
496
497 buf = OPENSSL_malloc(rsa_size);
498 if (!buf) {
499 OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
500 return 0;
501 }
502
503 if (!RSA_verify_raw(rsa, &len, buf, rsa_size, sig, sig_len,
504 RSA_PKCS1_PADDING)) {
505 goto out;
506 }
507
508 if (!RSA_add_pkcs1_prefix(&signed_msg, &signed_msg_len,
509 &signed_msg_is_alloced, hash_nid, msg, msg_len)) {
510 goto out;
511 }
512
513 if (len != signed_msg_len || CRYPTO_memcmp(buf, signed_msg, len) != 0) {
514 OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_SIGNATURE);
515 goto out;
516 }
517
518 ret = 1;
519
520 out:
521 OPENSSL_free(buf);
522 if (signed_msg_is_alloced) {
523 OPENSSL_free(signed_msg);
524 }
525 return ret;
526 }
527
bn_free_and_null(BIGNUM ** bn)528 static void bn_free_and_null(BIGNUM **bn) {
529 BN_free(*bn);
530 *bn = NULL;
531 }
532
RSA_check_key(const RSA * key)533 int RSA_check_key(const RSA *key) {
534 BIGNUM n, pm1, qm1, lcm, gcd, de, dmp1, dmq1, iqmp;
535 BN_CTX *ctx;
536 int ok = 0, has_crt_values;
537
538 if (RSA_is_opaque(key)) {
539 /* Opaque keys can't be checked. */
540 return 1;
541 }
542
543 if ((key->p != NULL) != (key->q != NULL)) {
544 OPENSSL_PUT_ERROR(RSA, RSA_R_ONLY_ONE_OF_P_Q_GIVEN);
545 return 0;
546 }
547
548 if (!key->n || !key->e) {
549 OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING);
550 return 0;
551 }
552
553 if (!key->d || !key->p) {
554 /* For a public key, or without p and q, there's nothing that can be
555 * checked. */
556 return 1;
557 }
558
559 ctx = BN_CTX_new();
560 if (ctx == NULL) {
561 OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
562 return 0;
563 }
564
565 BN_init(&n);
566 BN_init(&pm1);
567 BN_init(&qm1);
568 BN_init(&lcm);
569 BN_init(&gcd);
570 BN_init(&de);
571 BN_init(&dmp1);
572 BN_init(&dmq1);
573 BN_init(&iqmp);
574
575 if (!BN_mul(&n, key->p, key->q, ctx) ||
576 /* lcm = lcm(prime-1, for all primes) */
577 !BN_sub(&pm1, key->p, BN_value_one()) ||
578 !BN_sub(&qm1, key->q, BN_value_one()) ||
579 !BN_mul(&lcm, &pm1, &qm1, ctx) ||
580 !BN_gcd(&gcd, &pm1, &qm1, ctx)) {
581 OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
582 goto out;
583 }
584
585 size_t num_additional_primes = 0;
586 if (key->additional_primes != NULL) {
587 num_additional_primes = sk_RSA_additional_prime_num(key->additional_primes);
588 }
589
590 size_t i;
591 for (i = 0; i < num_additional_primes; i++) {
592 const RSA_additional_prime *ap =
593 sk_RSA_additional_prime_value(key->additional_primes, i);
594 if (!BN_mul(&n, &n, ap->prime, ctx) ||
595 !BN_sub(&pm1, ap->prime, BN_value_one()) ||
596 !BN_mul(&lcm, &lcm, &pm1, ctx) ||
597 !BN_gcd(&gcd, &gcd, &pm1, ctx)) {
598 OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
599 goto out;
600 }
601 }
602
603 if (!BN_div(&lcm, NULL, &lcm, &gcd, ctx) ||
604 !BN_gcd(&gcd, &pm1, &qm1, ctx) ||
605 /* de = d*e mod lcm(prime-1, for all primes). */
606 !BN_mod_mul(&de, key->d, key->e, &lcm, ctx)) {
607 OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
608 goto out;
609 }
610
611 if (BN_cmp(&n, key->n) != 0) {
612 OPENSSL_PUT_ERROR(RSA, RSA_R_N_NOT_EQUAL_P_Q);
613 goto out;
614 }
615
616 if (!BN_is_one(&de)) {
617 OPENSSL_PUT_ERROR(RSA, RSA_R_D_E_NOT_CONGRUENT_TO_1);
618 goto out;
619 }
620
621 has_crt_values = key->dmp1 != NULL;
622 if (has_crt_values != (key->dmq1 != NULL) ||
623 has_crt_values != (key->iqmp != NULL)) {
624 OPENSSL_PUT_ERROR(RSA, RSA_R_INCONSISTENT_SET_OF_CRT_VALUES);
625 goto out;
626 }
627
628 if (has_crt_values && num_additional_primes == 0) {
629 if (/* dmp1 = d mod (p-1) */
630 !BN_mod(&dmp1, key->d, &pm1, ctx) ||
631 /* dmq1 = d mod (q-1) */
632 !BN_mod(&dmq1, key->d, &qm1, ctx) ||
633 /* iqmp = q^-1 mod p */
634 !BN_mod_inverse(&iqmp, key->q, key->p, ctx)) {
635 OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
636 goto out;
637 }
638
639 if (BN_cmp(&dmp1, key->dmp1) != 0 ||
640 BN_cmp(&dmq1, key->dmq1) != 0 ||
641 BN_cmp(&iqmp, key->iqmp) != 0) {
642 OPENSSL_PUT_ERROR(RSA, RSA_R_CRT_VALUES_INCORRECT);
643 goto out;
644 }
645 }
646
647 ok = 1;
648
649 out:
650 BN_free(&n);
651 BN_free(&pm1);
652 BN_free(&qm1);
653 BN_free(&lcm);
654 BN_free(&gcd);
655 BN_free(&de);
656 BN_free(&dmp1);
657 BN_free(&dmq1);
658 BN_free(&iqmp);
659 BN_CTX_free(ctx);
660
661 return ok;
662 }
663
RSA_recover_crt_params(RSA * rsa)664 int RSA_recover_crt_params(RSA *rsa) {
665 BN_CTX *ctx;
666 BIGNUM *totient, *rem, *multiple, *p_plus_q, *p_minus_q;
667 int ok = 0;
668
669 if (rsa->n == NULL || rsa->e == NULL || rsa->d == NULL) {
670 OPENSSL_PUT_ERROR(RSA, RSA_R_EMPTY_PUBLIC_KEY);
671 return 0;
672 }
673
674 if (rsa->p || rsa->q || rsa->dmp1 || rsa->dmq1 || rsa->iqmp) {
675 OPENSSL_PUT_ERROR(RSA, RSA_R_CRT_PARAMS_ALREADY_GIVEN);
676 return 0;
677 }
678
679 if (rsa->additional_primes != NULL) {
680 OPENSSL_PUT_ERROR(RSA, RSA_R_CANNOT_RECOVER_MULTI_PRIME_KEY);
681 return 0;
682 }
683
684 /* This uses the algorithm from section 9B of the RSA paper:
685 * http://people.csail.mit.edu/rivest/Rsapaper.pdf */
686
687 ctx = BN_CTX_new();
688 if (ctx == NULL) {
689 OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
690 return 0;
691 }
692
693 BN_CTX_start(ctx);
694 totient = BN_CTX_get(ctx);
695 rem = BN_CTX_get(ctx);
696 multiple = BN_CTX_get(ctx);
697 p_plus_q = BN_CTX_get(ctx);
698 p_minus_q = BN_CTX_get(ctx);
699
700 if (totient == NULL || rem == NULL || multiple == NULL || p_plus_q == NULL ||
701 p_minus_q == NULL) {
702 OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
703 goto err;
704 }
705
706 /* ed-1 is a small multiple of φ(n). */
707 if (!BN_mul(totient, rsa->e, rsa->d, ctx) ||
708 !BN_sub_word(totient, 1) ||
709 /* φ(n) =
710 * pq - p - q + 1 =
711 * n - (p + q) + 1
712 *
713 * Thus n is a reasonable estimate for φ(n). So, (ed-1)/n will be very
714 * close. But, when we calculate the quotient, we'll be truncating it
715 * because we discard the remainder. Thus (ed-1)/multiple will be >= n,
716 * which the totient cannot be. So we add one to the estimate.
717 *
718 * Consider ed-1 as:
719 *
720 * multiple * (n - (p+q) + 1) =
721 * multiple*n - multiple*(p+q) + multiple
722 *
723 * When we divide by n, the first term becomes multiple and, since
724 * multiple and p+q is tiny compared to n, the second and third terms can
725 * be ignored. Thus I claim that subtracting one from the estimate is
726 * sufficient. */
727 !BN_div(multiple, NULL, totient, rsa->n, ctx) ||
728 !BN_add_word(multiple, 1) ||
729 !BN_div(totient, rem, totient, multiple, ctx)) {
730 OPENSSL_PUT_ERROR(RSA, ERR_R_BN_LIB);
731 goto err;
732 }
733
734 if (!BN_is_zero(rem)) {
735 OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_RSA_PARAMETERS);
736 goto err;
737 }
738
739 rsa->p = BN_new();
740 rsa->q = BN_new();
741 rsa->dmp1 = BN_new();
742 rsa->dmq1 = BN_new();
743 rsa->iqmp = BN_new();
744 if (rsa->p == NULL || rsa->q == NULL || rsa->dmp1 == NULL || rsa->dmq1 ==
745 NULL || rsa->iqmp == NULL) {
746 OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
747 goto err;
748 }
749
750 /* φ(n) = n - (p + q) + 1 =>
751 * n - totient + 1 = p + q */
752 if (!BN_sub(p_plus_q, rsa->n, totient) ||
753 !BN_add_word(p_plus_q, 1) ||
754 /* p - q = sqrt((p+q)^2 - 4n) */
755 !BN_sqr(rem, p_plus_q, ctx) ||
756 !BN_lshift(multiple, rsa->n, 2) ||
757 !BN_sub(rem, rem, multiple) ||
758 !BN_sqrt(p_minus_q, rem, ctx) ||
759 /* q is 1/2 (p+q)-(p-q) */
760 !BN_sub(rsa->q, p_plus_q, p_minus_q) ||
761 !BN_rshift1(rsa->q, rsa->q) ||
762 !BN_div(rsa->p, NULL, rsa->n, rsa->q, ctx) ||
763 !BN_mul(multiple, rsa->p, rsa->q, ctx)) {
764 OPENSSL_PUT_ERROR(RSA, ERR_R_BN_LIB);
765 goto err;
766 }
767
768 if (BN_cmp(multiple, rsa->n) != 0) {
769 OPENSSL_PUT_ERROR(RSA, RSA_R_INTERNAL_ERROR);
770 goto err;
771 }
772
773 if (!BN_sub(rem, rsa->p, BN_value_one()) ||
774 !BN_mod(rsa->dmp1, rsa->d, rem, ctx) ||
775 !BN_sub(rem, rsa->q, BN_value_one()) ||
776 !BN_mod(rsa->dmq1, rsa->d, rem, ctx) ||
777 !BN_mod_inverse(rsa->iqmp, rsa->q, rsa->p, ctx)) {
778 OPENSSL_PUT_ERROR(RSA, ERR_R_BN_LIB);
779 goto err;
780 }
781
782 ok = 1;
783
784 err:
785 BN_CTX_end(ctx);
786 BN_CTX_free(ctx);
787 if (!ok) {
788 bn_free_and_null(&rsa->p);
789 bn_free_and_null(&rsa->q);
790 bn_free_and_null(&rsa->dmp1);
791 bn_free_and_null(&rsa->dmq1);
792 bn_free_and_null(&rsa->iqmp);
793 }
794 return ok;
795 }
796
RSA_private_transform(RSA * rsa,uint8_t * out,const uint8_t * in,size_t len)797 int RSA_private_transform(RSA *rsa, uint8_t *out, const uint8_t *in,
798 size_t len) {
799 if (rsa->meth->private_transform) {
800 return rsa->meth->private_transform(rsa, out, in, len);
801 }
802
803 return rsa_default_private_transform(rsa, out, in, len);
804 }
805
RSA_blinding_on(RSA * rsa,BN_CTX * ctx)806 int RSA_blinding_on(RSA *rsa, BN_CTX *ctx) {
807 return 1;
808 }
809