Line data Source code
1 : /*
2 : * The RSA public-key cryptosystem
3 : *
4 : * Copyright The Mbed TLS Contributors
5 : * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6 : */
7 :
8 : /*
9 : * The following sources were referenced in the design of this implementation
10 : * of the RSA algorithm:
11 : *
12 : * [1] A method for obtaining digital signatures and public-key cryptosystems
13 : * R Rivest, A Shamir, and L Adleman
14 : * http://people.csail.mit.edu/rivest/pubs.html#RSA78
15 : *
16 : * [2] Handbook of Applied Cryptography - 1997, Chapter 8
17 : * Menezes, van Oorschot and Vanstone
18 : *
19 : * [3] Malware Guard Extension: Using SGX to Conceal Cache Attacks
20 : * Michael Schwarz, Samuel Weiser, Daniel Gruss, Clémentine Maurice and
21 : * Stefan Mangard
22 : * https://arxiv.org/abs/1702.08719v2
23 : *
24 : */
25 :
26 : #include "common.h"
27 :
28 : #if defined(MBEDTLS_RSA_C)
29 :
30 : #include "mbedtls/rsa.h"
31 : #include "bignum_core.h"
32 : #include "bignum_internal.h"
33 : #include "rsa_alt_helpers.h"
34 : #include "rsa_internal.h"
35 : #include "mbedtls/oid.h"
36 : #include "mbedtls/asn1write.h"
37 : #include "mbedtls/platform_util.h"
38 : #include "mbedtls/error.h"
39 : #include "constant_time_internal.h"
40 : #include "mbedtls/constant_time.h"
41 : #include "md_psa.h"
42 :
43 : #include <string.h>
44 :
45 : #if defined(MBEDTLS_PKCS1_V15) && !defined(__OpenBSD__) && !defined(__NetBSD__)
46 : #include <stdlib.h>
47 : #endif
48 :
49 : #include "mbedtls/platform.h"
50 :
51 : /*
52 : * Wrapper around mbedtls_asn1_get_mpi() that rejects zero.
53 : *
54 : * The value zero is:
55 : * - never a valid value for an RSA parameter
56 : * - interpreted as "omitted, please reconstruct" by mbedtls_rsa_complete().
57 : *
58 : * Since values can't be omitted in PKCS#1, passing a zero value to
59 : * rsa_complete() would be incorrect, so reject zero values early.
60 : */
61 288 : static int asn1_get_nonzero_mpi(unsigned char **p,
62 : const unsigned char *end,
63 : mbedtls_mpi *X)
64 : {
65 : int ret;
66 :
67 288 : ret = mbedtls_asn1_get_mpi(p, end, X);
68 288 : if (ret != 0) {
69 0 : return ret;
70 : }
71 :
72 288 : if (mbedtls_mpi_cmp_int(X, 0) == 0) {
73 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
74 : }
75 :
76 288 : return 0;
77 : }
78 :
79 36 : int mbedtls_rsa_parse_key(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen)
80 : {
81 : int ret, version;
82 : size_t len;
83 : unsigned char *p, *end;
84 :
85 : mbedtls_mpi T;
86 36 : mbedtls_mpi_init(&T);
87 :
88 36 : p = (unsigned char *) key;
89 36 : end = p + keylen;
90 :
91 : /*
92 : * This function parses the RSAPrivateKey (PKCS#1)
93 : *
94 : * RSAPrivateKey ::= SEQUENCE {
95 : * version Version,
96 : * modulus INTEGER, -- n
97 : * publicExponent INTEGER, -- e
98 : * privateExponent INTEGER, -- d
99 : * prime1 INTEGER, -- p
100 : * prime2 INTEGER, -- q
101 : * exponent1 INTEGER, -- d mod (p-1)
102 : * exponent2 INTEGER, -- d mod (q-1)
103 : * coefficient INTEGER, -- (inverse of q) mod p
104 : * otherPrimeInfos OtherPrimeInfos OPTIONAL
105 : * }
106 : */
107 36 : if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
108 : MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
109 0 : return ret;
110 : }
111 :
112 36 : if (end != p + len) {
113 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
114 : }
115 :
116 36 : if ((ret = mbedtls_asn1_get_int(&p, end, &version)) != 0) {
117 0 : return ret;
118 : }
119 :
120 36 : if (version != 0) {
121 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
122 : }
123 :
124 : /* Import N */
125 72 : if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
126 36 : (ret = mbedtls_rsa_import(rsa, &T, NULL, NULL,
127 : NULL, NULL)) != 0) {
128 0 : goto cleanup;
129 : }
130 :
131 : /* Import E */
132 72 : if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
133 36 : (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL,
134 : NULL, &T)) != 0) {
135 0 : goto cleanup;
136 : }
137 :
138 : /* Import D */
139 72 : if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
140 36 : (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL,
141 : &T, NULL)) != 0) {
142 0 : goto cleanup;
143 : }
144 :
145 : /* Import P */
146 72 : if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
147 36 : (ret = mbedtls_rsa_import(rsa, NULL, &T, NULL,
148 : NULL, NULL)) != 0) {
149 0 : goto cleanup;
150 : }
151 :
152 : /* Import Q */
153 72 : if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
154 36 : (ret = mbedtls_rsa_import(rsa, NULL, NULL, &T,
155 : NULL, NULL)) != 0) {
156 0 : goto cleanup;
157 : }
158 :
159 : #if !defined(MBEDTLS_RSA_NO_CRT) && !defined(MBEDTLS_RSA_ALT)
160 : /*
161 : * The RSA CRT parameters DP, DQ and QP are nominally redundant, in
162 : * that they can be easily recomputed from D, P and Q. However by
163 : * parsing them from the PKCS1 structure it is possible to avoid
164 : * recalculating them which both reduces the overhead of loading
165 : * RSA private keys into memory and also avoids side channels which
166 : * can arise when computing those values, since all of D, P, and Q
167 : * are secret. See https://eprint.iacr.org/2020/055 for a
168 : * description of one such attack.
169 : */
170 :
171 : /* Import DP */
172 72 : if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
173 36 : (ret = mbedtls_mpi_copy(&rsa->DP, &T)) != 0) {
174 0 : goto cleanup;
175 : }
176 :
177 : /* Import DQ */
178 72 : if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
179 36 : (ret = mbedtls_mpi_copy(&rsa->DQ, &T)) != 0) {
180 0 : goto cleanup;
181 : }
182 :
183 : /* Import QP */
184 72 : if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
185 36 : (ret = mbedtls_mpi_copy(&rsa->QP, &T)) != 0) {
186 0 : goto cleanup;
187 : }
188 :
189 : #else
190 : /* Verify existence of the CRT params */
191 : if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
192 : (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
193 : (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0) {
194 : goto cleanup;
195 : }
196 : #endif
197 :
198 : /* rsa_complete() doesn't complete anything with the default
199 : * implementation but is still called:
200 : * - for the benefit of alternative implementation that may want to
201 : * pre-compute stuff beyond what's provided (eg Montgomery factors)
202 : * - as is also sanity-checks the key
203 : *
204 : * Furthermore, we also check the public part for consistency with
205 : * mbedtls_pk_parse_pubkey(), as it includes size minima for example.
206 : */
207 72 : if ((ret = mbedtls_rsa_complete(rsa)) != 0 ||
208 36 : (ret = mbedtls_rsa_check_pubkey(rsa)) != 0) {
209 0 : goto cleanup;
210 : }
211 :
212 36 : if (p != end) {
213 0 : ret = MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
214 : }
215 :
216 36 : cleanup:
217 :
218 36 : mbedtls_mpi_free(&T);
219 :
220 36 : if (ret != 0) {
221 0 : mbedtls_rsa_free(rsa);
222 : }
223 :
224 36 : return ret;
225 : }
226 :
227 1397 : int mbedtls_rsa_parse_pubkey(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen)
228 : {
229 1397 : unsigned char *p = (unsigned char *) key;
230 1397 : unsigned char *end = (unsigned char *) (key + keylen);
231 1397 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
232 : size_t len;
233 :
234 : /*
235 : * RSAPublicKey ::= SEQUENCE {
236 : * modulus INTEGER, -- n
237 : * publicExponent INTEGER -- e
238 : * }
239 : */
240 :
241 1397 : if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
242 : MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
243 0 : return ret;
244 : }
245 :
246 1397 : if (end != p + len) {
247 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
248 : }
249 :
250 : /* Import N */
251 1397 : if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
252 10 : return ret;
253 : }
254 :
255 1387 : if ((ret = mbedtls_rsa_import_raw(rsa, p, len, NULL, 0, NULL, 0,
256 : NULL, 0, NULL, 0)) != 0) {
257 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
258 : }
259 :
260 1387 : p += len;
261 :
262 : /* Import E */
263 1387 : if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
264 0 : return ret;
265 : }
266 :
267 1387 : if ((ret = mbedtls_rsa_import_raw(rsa, NULL, 0, NULL, 0, NULL, 0,
268 : NULL, 0, p, len)) != 0) {
269 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
270 : }
271 :
272 1387 : p += len;
273 :
274 2774 : if (mbedtls_rsa_complete(rsa) != 0 ||
275 1387 : mbedtls_rsa_check_pubkey(rsa) != 0) {
276 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
277 : }
278 :
279 1387 : if (p != end) {
280 0 : return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
281 : }
282 :
283 1387 : return 0;
284 : }
285 :
286 0 : int mbedtls_rsa_write_key(const mbedtls_rsa_context *rsa, unsigned char *start,
287 : unsigned char **p)
288 : {
289 0 : size_t len = 0;
290 : int ret;
291 :
292 : mbedtls_mpi T; /* Temporary holding the exported parameters */
293 :
294 : /*
295 : * Export the parameters one after another to avoid simultaneous copies.
296 : */
297 :
298 0 : mbedtls_mpi_init(&T);
299 :
300 : /* Export QP */
301 0 : if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 ||
302 0 : (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
303 0 : goto end_of_export;
304 : }
305 0 : len += ret;
306 :
307 : /* Export DQ */
308 0 : if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 ||
309 0 : (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
310 0 : goto end_of_export;
311 : }
312 0 : len += ret;
313 :
314 : /* Export DP */
315 0 : if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 ||
316 0 : (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
317 0 : goto end_of_export;
318 : }
319 0 : len += ret;
320 :
321 : /* Export Q */
322 0 : if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, &T, NULL, NULL)) != 0 ||
323 0 : (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
324 0 : goto end_of_export;
325 : }
326 0 : len += ret;
327 :
328 : /* Export P */
329 0 : if ((ret = mbedtls_rsa_export(rsa, NULL, &T, NULL, NULL, NULL)) != 0 ||
330 0 : (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
331 0 : goto end_of_export;
332 : }
333 0 : len += ret;
334 :
335 : /* Export D */
336 0 : if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, &T, NULL)) != 0 ||
337 0 : (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
338 0 : goto end_of_export;
339 : }
340 0 : len += ret;
341 :
342 : /* Export E */
343 0 : if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
344 0 : (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
345 0 : goto end_of_export;
346 : }
347 0 : len += ret;
348 :
349 : /* Export N */
350 0 : if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
351 0 : (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
352 0 : goto end_of_export;
353 : }
354 0 : len += ret;
355 :
356 0 : end_of_export:
357 :
358 0 : mbedtls_mpi_free(&T);
359 0 : if (ret < 0) {
360 0 : return ret;
361 : }
362 :
363 0 : MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, start, 0));
364 0 : MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
365 0 : MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start,
366 : MBEDTLS_ASN1_CONSTRUCTED |
367 : MBEDTLS_ASN1_SEQUENCE));
368 :
369 0 : return (int) len;
370 : }
371 :
372 : /*
373 : * RSAPublicKey ::= SEQUENCE {
374 : * modulus INTEGER, -- n
375 : * publicExponent INTEGER -- e
376 : * }
377 : */
378 0 : int mbedtls_rsa_write_pubkey(const mbedtls_rsa_context *rsa, unsigned char *start,
379 : unsigned char **p)
380 : {
381 0 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
382 0 : size_t len = 0;
383 : mbedtls_mpi T;
384 :
385 0 : mbedtls_mpi_init(&T);
386 :
387 : /* Export E */
388 0 : if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
389 0 : (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
390 0 : goto end_of_export;
391 : }
392 0 : len += ret;
393 :
394 : /* Export N */
395 0 : if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
396 0 : (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
397 0 : goto end_of_export;
398 : }
399 0 : len += ret;
400 :
401 0 : end_of_export:
402 :
403 0 : mbedtls_mpi_free(&T);
404 0 : if (ret < 0) {
405 0 : return ret;
406 : }
407 :
408 0 : MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
409 0 : MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED |
410 : MBEDTLS_ASN1_SEQUENCE));
411 :
412 0 : return (int) len;
413 : }
414 :
415 : #if defined(MBEDTLS_PKCS1_V15) && defined(MBEDTLS_RSA_C) && !defined(MBEDTLS_RSA_ALT)
416 :
417 : /** This function performs the unpadding part of a PKCS#1 v1.5 decryption
418 : * operation (EME-PKCS1-v1_5 decoding).
419 : *
420 : * \note The return value from this function is a sensitive value
421 : * (this is unusual). #MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE shouldn't happen
422 : * in a well-written application, but 0 vs #MBEDTLS_ERR_RSA_INVALID_PADDING
423 : * is often a situation that an attacker can provoke and leaking which
424 : * one is the result is precisely the information the attacker wants.
425 : *
426 : * \param input The input buffer which is the payload inside PKCS#1v1.5
427 : * encryption padding, called the "encoded message EM"
428 : * by the terminology.
429 : * \param ilen The length of the payload in the \p input buffer.
430 : * \param output The buffer for the payload, called "message M" by the
431 : * PKCS#1 terminology. This must be a writable buffer of
432 : * length \p output_max_len bytes.
433 : * \param olen The address at which to store the length of
434 : * the payload. This must not be \c NULL.
435 : * \param output_max_len The length in bytes of the output buffer \p output.
436 : *
437 : * \return \c 0 on success.
438 : * \return #MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE
439 : * The output buffer is too small for the unpadded payload.
440 : * \return #MBEDTLS_ERR_RSA_INVALID_PADDING
441 : * The input doesn't contain properly formatted padding.
442 : */
443 0 : static int mbedtls_ct_rsaes_pkcs1_v15_unpadding(unsigned char *input,
444 : size_t ilen,
445 : unsigned char *output,
446 : size_t output_max_len,
447 : size_t *olen)
448 : {
449 0 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
450 : size_t i, plaintext_max_size;
451 :
452 : /* The following variables take sensitive values: their value must
453 : * not leak into the observable behavior of the function other than
454 : * the designated outputs (output, olen, return value). Otherwise
455 : * this would open the execution of the function to
456 : * side-channel-based variants of the Bleichenbacher padding oracle
457 : * attack. Potential side channels include overall timing, memory
458 : * access patterns (especially visible to an adversary who has access
459 : * to a shared memory cache), and branches (especially visible to
460 : * an adversary who has access to a shared code cache or to a shared
461 : * branch predictor). */
462 0 : size_t pad_count = 0;
463 : mbedtls_ct_condition_t bad;
464 : mbedtls_ct_condition_t pad_done;
465 0 : size_t plaintext_size = 0;
466 : mbedtls_ct_condition_t output_too_large;
467 :
468 0 : plaintext_max_size = (output_max_len > ilen - 11) ? ilen - 11
469 : : output_max_len;
470 :
471 : /* Check and get padding length in constant time and constant
472 : * memory trace. The first byte must be 0. */
473 0 : bad = mbedtls_ct_bool(input[0]);
474 :
475 :
476 : /* Decode EME-PKCS1-v1_5 padding: 0x00 || 0x02 || PS || 0x00
477 : * where PS must be at least 8 nonzero bytes. */
478 0 : bad = mbedtls_ct_bool_or(bad, mbedtls_ct_uint_ne(input[1], MBEDTLS_RSA_CRYPT));
479 :
480 : /* Read the whole buffer. Set pad_done to nonzero if we find
481 : * the 0x00 byte and remember the padding length in pad_count. */
482 0 : pad_done = MBEDTLS_CT_FALSE;
483 0 : for (i = 2; i < ilen; i++) {
484 0 : mbedtls_ct_condition_t found = mbedtls_ct_uint_eq(input[i], 0);
485 0 : pad_done = mbedtls_ct_bool_or(pad_done, found);
486 0 : pad_count += mbedtls_ct_uint_if_else_0(mbedtls_ct_bool_not(pad_done), 1);
487 : }
488 :
489 : /* If pad_done is still zero, there's no data, only unfinished padding. */
490 0 : bad = mbedtls_ct_bool_or(bad, mbedtls_ct_bool_not(pad_done));
491 :
492 : /* There must be at least 8 bytes of padding. */
493 0 : bad = mbedtls_ct_bool_or(bad, mbedtls_ct_uint_gt(8, pad_count));
494 :
495 : /* If the padding is valid, set plaintext_size to the number of
496 : * remaining bytes after stripping the padding. If the padding
497 : * is invalid, avoid leaking this fact through the size of the
498 : * output: use the maximum message size that fits in the output
499 : * buffer. Do it without branches to avoid leaking the padding
500 : * validity through timing. RSA keys are small enough that all the
501 : * size_t values involved fit in unsigned int. */
502 0 : plaintext_size = mbedtls_ct_uint_if(
503 : bad, (unsigned) plaintext_max_size,
504 0 : (unsigned) (ilen - pad_count - 3));
505 :
506 : /* Set output_too_large to 0 if the plaintext fits in the output
507 : * buffer and to 1 otherwise. */
508 0 : output_too_large = mbedtls_ct_uint_gt(plaintext_size,
509 : plaintext_max_size);
510 :
511 : /* Set ret without branches to avoid timing attacks. Return:
512 : * - INVALID_PADDING if the padding is bad (bad != 0).
513 : * - OUTPUT_TOO_LARGE if the padding is good but the decrypted
514 : * plaintext does not fit in the output buffer.
515 : * - 0 if the padding is correct. */
516 0 : ret = mbedtls_ct_error_if(
517 : bad,
518 : MBEDTLS_ERR_RSA_INVALID_PADDING,
519 : mbedtls_ct_error_if_else_0(output_too_large, MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE)
520 : );
521 :
522 : /* If the padding is bad or the plaintext is too large, zero the
523 : * data that we're about to copy to the output buffer.
524 : * We need to copy the same amount of data
525 : * from the same buffer whether the padding is good or not to
526 : * avoid leaking the padding validity through overall timing or
527 : * through memory or cache access patterns. */
528 0 : mbedtls_ct_zeroize_if(mbedtls_ct_bool_or(bad, output_too_large), input + 11, ilen - 11);
529 :
530 : /* If the plaintext is too large, truncate it to the buffer size.
531 : * Copy anyway to avoid revealing the length through timing, because
532 : * revealing the length is as bad as revealing the padding validity
533 : * for a Bleichenbacher attack. */
534 0 : plaintext_size = mbedtls_ct_uint_if(output_too_large,
535 : (unsigned) plaintext_max_size,
536 : (unsigned) plaintext_size);
537 :
538 : /* Move the plaintext to the leftmost position where it can start in
539 : * the working buffer, i.e. make it start plaintext_max_size from
540 : * the end of the buffer. Do this with a memory access trace that
541 : * does not depend on the plaintext size. After this move, the
542 : * starting location of the plaintext is no longer sensitive
543 : * information. */
544 0 : mbedtls_ct_memmove_left(input + ilen - plaintext_max_size,
545 : plaintext_max_size,
546 : plaintext_max_size - plaintext_size);
547 :
548 : /* Finally copy the decrypted plaintext plus trailing zeros into the output
549 : * buffer. If output_max_len is 0, then output may be an invalid pointer
550 : * and the result of memcpy() would be undefined; prevent undefined
551 : * behavior making sure to depend only on output_max_len (the size of the
552 : * user-provided output buffer), which is independent from plaintext
553 : * length, validity of padding, success of the decryption, and other
554 : * secrets. */
555 0 : if (output_max_len != 0) {
556 0 : memcpy(output, input + ilen - plaintext_max_size, plaintext_max_size);
557 : }
558 :
559 : /* Report the amount of data we copied to the output buffer. In case
560 : * of errors (bad padding or output too large), the value of *olen
561 : * when this function returns is not specified. Making it equivalent
562 : * to the good case limits the risks of leaking the padding validity. */
563 0 : *olen = plaintext_size;
564 :
565 0 : return ret;
566 : }
567 :
568 : #endif /* MBEDTLS_PKCS1_V15 && MBEDTLS_RSA_C && ! MBEDTLS_RSA_ALT */
569 :
570 : #if !defined(MBEDTLS_RSA_ALT)
571 :
572 186 : int mbedtls_rsa_import(mbedtls_rsa_context *ctx,
573 : const mbedtls_mpi *N,
574 : const mbedtls_mpi *P, const mbedtls_mpi *Q,
575 : const mbedtls_mpi *D, const mbedtls_mpi *E)
576 : {
577 186 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
578 :
579 186 : if ((N != NULL && (ret = mbedtls_mpi_copy(&ctx->N, N)) != 0) ||
580 186 : (P != NULL && (ret = mbedtls_mpi_copy(&ctx->P, P)) != 0) ||
581 186 : (Q != NULL && (ret = mbedtls_mpi_copy(&ctx->Q, Q)) != 0) ||
582 186 : (D != NULL && (ret = mbedtls_mpi_copy(&ctx->D, D)) != 0) ||
583 38 : (E != NULL && (ret = mbedtls_mpi_copy(&ctx->E, E)) != 0)) {
584 0 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret);
585 : }
586 :
587 186 : if (N != NULL) {
588 38 : ctx->len = mbedtls_mpi_size(&ctx->N);
589 : }
590 :
591 186 : return 0;
592 : }
593 :
594 2774 : int mbedtls_rsa_import_raw(mbedtls_rsa_context *ctx,
595 : unsigned char const *N, size_t N_len,
596 : unsigned char const *P, size_t P_len,
597 : unsigned char const *Q, size_t Q_len,
598 : unsigned char const *D, size_t D_len,
599 : unsigned char const *E, size_t E_len)
600 : {
601 2774 : int ret = 0;
602 :
603 2774 : if (N != NULL) {
604 1387 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&ctx->N, N, N_len));
605 1387 : ctx->len = mbedtls_mpi_size(&ctx->N);
606 : }
607 :
608 2774 : if (P != NULL) {
609 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&ctx->P, P, P_len));
610 : }
611 :
612 2774 : if (Q != NULL) {
613 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&ctx->Q, Q, Q_len));
614 : }
615 :
616 2774 : if (D != NULL) {
617 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&ctx->D, D, D_len));
618 : }
619 :
620 2774 : if (E != NULL) {
621 1387 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&ctx->E, E, E_len));
622 : }
623 :
624 2774 : cleanup:
625 :
626 2774 : if (ret != 0) {
627 0 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret);
628 : }
629 :
630 2774 : return 0;
631 : }
632 :
633 : /*
634 : * Checks whether the context fields are set in such a way
635 : * that the RSA primitives will be able to execute without error.
636 : * It does *not* make guarantees for consistency of the parameters.
637 : */
638 3300 : static int rsa_check_context(mbedtls_rsa_context const *ctx, int is_priv,
639 : int blinding_needed)
640 : {
641 : #if !defined(MBEDTLS_RSA_NO_CRT)
642 : /* blinding_needed is only used for NO_CRT to decide whether
643 : * P,Q need to be present or not. */
644 : ((void) blinding_needed);
645 : #endif
646 :
647 3300 : if (ctx->len != mbedtls_mpi_size(&ctx->N) ||
648 3300 : ctx->len > MBEDTLS_MPI_MAX_SIZE) {
649 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
650 : }
651 :
652 : /*
653 : * 1. Modular exponentiation needs positive, odd moduli.
654 : */
655 :
656 : /* Modular exponentiation wrt. N is always used for
657 : * RSA public key operations. */
658 6600 : if (mbedtls_mpi_cmp_int(&ctx->N, 0) <= 0 ||
659 3300 : mbedtls_mpi_get_bit(&ctx->N, 0) == 0) {
660 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
661 : }
662 :
663 : #if !defined(MBEDTLS_RSA_NO_CRT)
664 : /* Modular exponentiation for P and Q is only
665 : * used for private key operations and if CRT
666 : * is used. */
667 3421 : if (is_priv &&
668 242 : (mbedtls_mpi_cmp_int(&ctx->P, 0) <= 0 ||
669 242 : mbedtls_mpi_get_bit(&ctx->P, 0) == 0 ||
670 242 : mbedtls_mpi_cmp_int(&ctx->Q, 0) <= 0 ||
671 121 : mbedtls_mpi_get_bit(&ctx->Q, 0) == 0)) {
672 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
673 : }
674 : #endif /* !MBEDTLS_RSA_NO_CRT */
675 :
676 : /*
677 : * 2. Exponents must be positive
678 : */
679 :
680 : /* Always need E for public key operations */
681 3300 : if (mbedtls_mpi_cmp_int(&ctx->E, 0) <= 0) {
682 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
683 : }
684 :
685 : #if defined(MBEDTLS_RSA_NO_CRT)
686 : /* For private key operations, use D or DP & DQ
687 : * as (unblinded) exponents. */
688 : if (is_priv && mbedtls_mpi_cmp_int(&ctx->D, 0) <= 0) {
689 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
690 : }
691 : #else
692 3421 : if (is_priv &&
693 242 : (mbedtls_mpi_cmp_int(&ctx->DP, 0) <= 0 ||
694 121 : mbedtls_mpi_cmp_int(&ctx->DQ, 0) <= 0)) {
695 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
696 : }
697 : #endif /* MBEDTLS_RSA_NO_CRT */
698 :
699 : /* Blinding shouldn't make exponents negative either,
700 : * so check that P, Q >= 1 if that hasn't yet been
701 : * done as part of 1. */
702 : #if defined(MBEDTLS_RSA_NO_CRT)
703 : if (is_priv && blinding_needed &&
704 : (mbedtls_mpi_cmp_int(&ctx->P, 0) <= 0 ||
705 : mbedtls_mpi_cmp_int(&ctx->Q, 0) <= 0)) {
706 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
707 : }
708 : #endif
709 :
710 : /* It wouldn't lead to an error if it wasn't satisfied,
711 : * but check for QP >= 1 nonetheless. */
712 : #if !defined(MBEDTLS_RSA_NO_CRT)
713 3421 : if (is_priv &&
714 121 : mbedtls_mpi_cmp_int(&ctx->QP, 0) <= 0) {
715 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
716 : }
717 : #endif
718 :
719 3300 : return 0;
720 : }
721 :
722 1493 : int mbedtls_rsa_complete(mbedtls_rsa_context *ctx)
723 : {
724 1493 : int ret = 0;
725 : int have_N, have_P, have_Q, have_D, have_E;
726 : #if !defined(MBEDTLS_RSA_NO_CRT)
727 : int have_DP, have_DQ, have_QP;
728 : #endif
729 : int n_missing, pq_missing, d_missing, is_pub, is_priv;
730 :
731 1493 : have_N = (mbedtls_mpi_cmp_int(&ctx->N, 0) != 0);
732 1493 : have_P = (mbedtls_mpi_cmp_int(&ctx->P, 0) != 0);
733 1493 : have_Q = (mbedtls_mpi_cmp_int(&ctx->Q, 0) != 0);
734 1493 : have_D = (mbedtls_mpi_cmp_int(&ctx->D, 0) != 0);
735 1493 : have_E = (mbedtls_mpi_cmp_int(&ctx->E, 0) != 0);
736 :
737 : #if !defined(MBEDTLS_RSA_NO_CRT)
738 1493 : have_DP = (mbedtls_mpi_cmp_int(&ctx->DP, 0) != 0);
739 1493 : have_DQ = (mbedtls_mpi_cmp_int(&ctx->DQ, 0) != 0);
740 1493 : have_QP = (mbedtls_mpi_cmp_int(&ctx->QP, 0) != 0);
741 : #endif
742 :
743 : /*
744 : * Check whether provided parameters are enough
745 : * to deduce all others. The following incomplete
746 : * parameter sets for private keys are supported:
747 : *
748 : * (1) P, Q missing.
749 : * (2) D and potentially N missing.
750 : *
751 : */
752 :
753 1493 : n_missing = have_P && have_Q && have_D && have_E;
754 1493 : pq_missing = have_N && !have_P && !have_Q && have_D && have_E;
755 1493 : d_missing = have_P && have_Q && !have_D && have_E;
756 1493 : is_pub = have_N && !have_P && !have_Q && !have_D && have_E;
757 :
758 : /* These three alternatives are mutually exclusive */
759 1493 : is_priv = n_missing || pq_missing || d_missing;
760 :
761 1493 : if (!is_priv && !is_pub) {
762 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
763 : }
764 :
765 : /*
766 : * Step 1: Deduce N if P, Q are provided.
767 : */
768 :
769 1493 : if (!have_N && have_P && have_Q) {
770 0 : if ((ret = mbedtls_mpi_mul_mpi(&ctx->N, &ctx->P,
771 0 : &ctx->Q)) != 0) {
772 0 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret);
773 : }
774 :
775 0 : ctx->len = mbedtls_mpi_size(&ctx->N);
776 : }
777 :
778 : /*
779 : * Step 2: Deduce and verify all remaining core parameters.
780 : */
781 :
782 1493 : if (pq_missing) {
783 2 : ret = mbedtls_rsa_deduce_primes(&ctx->N, &ctx->E, &ctx->D,
784 : &ctx->P, &ctx->Q);
785 2 : if (ret != 0) {
786 0 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret);
787 : }
788 :
789 1491 : } else if (d_missing) {
790 0 : if ((ret = mbedtls_rsa_deduce_private_exponent(&ctx->P,
791 0 : &ctx->Q,
792 0 : &ctx->E,
793 : &ctx->D)) != 0) {
794 0 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret);
795 : }
796 : }
797 :
798 : /*
799 : * Step 3: Deduce all additional parameters specific
800 : * to our current RSA implementation.
801 : */
802 :
803 : #if !defined(MBEDTLS_RSA_NO_CRT)
804 1493 : if (is_priv && !(have_DP && have_DQ && have_QP)) {
805 2 : ret = mbedtls_rsa_deduce_crt(&ctx->P, &ctx->Q, &ctx->D,
806 : &ctx->DP, &ctx->DQ, &ctx->QP);
807 2 : if (ret != 0) {
808 0 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret);
809 : }
810 : }
811 : #endif /* MBEDTLS_RSA_NO_CRT */
812 :
813 : /*
814 : * Step 3: Basic sanity checks
815 : */
816 :
817 1493 : return rsa_check_context(ctx, is_priv, 1);
818 : }
819 :
820 0 : int mbedtls_rsa_export_raw(const mbedtls_rsa_context *ctx,
821 : unsigned char *N, size_t N_len,
822 : unsigned char *P, size_t P_len,
823 : unsigned char *Q, size_t Q_len,
824 : unsigned char *D, size_t D_len,
825 : unsigned char *E, size_t E_len)
826 : {
827 0 : int ret = 0;
828 : int is_priv;
829 :
830 : /* Check if key is private or public */
831 0 : is_priv =
832 0 : mbedtls_mpi_cmp_int(&ctx->N, 0) != 0 &&
833 0 : mbedtls_mpi_cmp_int(&ctx->P, 0) != 0 &&
834 0 : mbedtls_mpi_cmp_int(&ctx->Q, 0) != 0 &&
835 0 : mbedtls_mpi_cmp_int(&ctx->D, 0) != 0 &&
836 0 : mbedtls_mpi_cmp_int(&ctx->E, 0) != 0;
837 :
838 0 : if (!is_priv) {
839 : /* If we're trying to export private parameters for a public key,
840 : * something must be wrong. */
841 0 : if (P != NULL || Q != NULL || D != NULL) {
842 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
843 : }
844 :
845 : }
846 :
847 0 : if (N != NULL) {
848 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->N, N, N_len));
849 : }
850 :
851 0 : if (P != NULL) {
852 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->P, P, P_len));
853 : }
854 :
855 0 : if (Q != NULL) {
856 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->Q, Q, Q_len));
857 : }
858 :
859 0 : if (D != NULL) {
860 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->D, D, D_len));
861 : }
862 :
863 0 : if (E != NULL) {
864 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->E, E, E_len));
865 : }
866 :
867 0 : cleanup:
868 :
869 0 : return ret;
870 : }
871 :
872 0 : int mbedtls_rsa_export(const mbedtls_rsa_context *ctx,
873 : mbedtls_mpi *N, mbedtls_mpi *P, mbedtls_mpi *Q,
874 : mbedtls_mpi *D, mbedtls_mpi *E)
875 : {
876 0 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
877 : int is_priv;
878 :
879 : /* Check if key is private or public */
880 0 : is_priv =
881 0 : mbedtls_mpi_cmp_int(&ctx->N, 0) != 0 &&
882 0 : mbedtls_mpi_cmp_int(&ctx->P, 0) != 0 &&
883 0 : mbedtls_mpi_cmp_int(&ctx->Q, 0) != 0 &&
884 0 : mbedtls_mpi_cmp_int(&ctx->D, 0) != 0 &&
885 0 : mbedtls_mpi_cmp_int(&ctx->E, 0) != 0;
886 :
887 0 : if (!is_priv) {
888 : /* If we're trying to export private parameters for a public key,
889 : * something must be wrong. */
890 0 : if (P != NULL || Q != NULL || D != NULL) {
891 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
892 : }
893 :
894 : }
895 :
896 : /* Export all requested core parameters. */
897 :
898 0 : if ((N != NULL && (ret = mbedtls_mpi_copy(N, &ctx->N)) != 0) ||
899 0 : (P != NULL && (ret = mbedtls_mpi_copy(P, &ctx->P)) != 0) ||
900 0 : (Q != NULL && (ret = mbedtls_mpi_copy(Q, &ctx->Q)) != 0) ||
901 0 : (D != NULL && (ret = mbedtls_mpi_copy(D, &ctx->D)) != 0) ||
902 0 : (E != NULL && (ret = mbedtls_mpi_copy(E, &ctx->E)) != 0)) {
903 0 : return ret;
904 : }
905 :
906 0 : return 0;
907 : }
908 :
909 : /*
910 : * Export CRT parameters
911 : * This must also be implemented if CRT is not used, for being able to
912 : * write DER encoded RSA keys. The helper function mbedtls_rsa_deduce_crt
913 : * can be used in this case.
914 : */
915 0 : int mbedtls_rsa_export_crt(const mbedtls_rsa_context *ctx,
916 : mbedtls_mpi *DP, mbedtls_mpi *DQ, mbedtls_mpi *QP)
917 : {
918 0 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
919 : int is_priv;
920 :
921 : /* Check if key is private or public */
922 0 : is_priv =
923 0 : mbedtls_mpi_cmp_int(&ctx->N, 0) != 0 &&
924 0 : mbedtls_mpi_cmp_int(&ctx->P, 0) != 0 &&
925 0 : mbedtls_mpi_cmp_int(&ctx->Q, 0) != 0 &&
926 0 : mbedtls_mpi_cmp_int(&ctx->D, 0) != 0 &&
927 0 : mbedtls_mpi_cmp_int(&ctx->E, 0) != 0;
928 :
929 0 : if (!is_priv) {
930 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
931 : }
932 :
933 : #if !defined(MBEDTLS_RSA_NO_CRT)
934 : /* Export all requested blinding parameters. */
935 0 : if ((DP != NULL && (ret = mbedtls_mpi_copy(DP, &ctx->DP)) != 0) ||
936 0 : (DQ != NULL && (ret = mbedtls_mpi_copy(DQ, &ctx->DQ)) != 0) ||
937 0 : (QP != NULL && (ret = mbedtls_mpi_copy(QP, &ctx->QP)) != 0)) {
938 0 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret);
939 : }
940 : #else
941 : if ((ret = mbedtls_rsa_deduce_crt(&ctx->P, &ctx->Q, &ctx->D,
942 : DP, DQ, QP)) != 0) {
943 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret);
944 : }
945 : #endif
946 :
947 0 : return 0;
948 : }
949 :
950 : /*
951 : * Initialize an RSA context
952 : */
953 1573 : void mbedtls_rsa_init(mbedtls_rsa_context *ctx)
954 : {
955 1573 : memset(ctx, 0, sizeof(mbedtls_rsa_context));
956 :
957 1573 : ctx->padding = MBEDTLS_RSA_PKCS_V15;
958 1573 : ctx->hash_id = MBEDTLS_MD_NONE;
959 :
960 : #if defined(MBEDTLS_THREADING_C)
961 : /* Set ctx->ver to nonzero to indicate that the mutex has been
962 : * initialized and will need to be freed. */
963 : ctx->ver = 1;
964 : mbedtls_mutex_init(&ctx->mutex);
965 : #endif
966 1573 : }
967 :
968 : /*
969 : * Set padding for an existing RSA context
970 : */
971 70 : int mbedtls_rsa_set_padding(mbedtls_rsa_context *ctx, int padding,
972 : mbedtls_md_type_t hash_id)
973 : {
974 70 : switch (padding) {
975 : #if defined(MBEDTLS_PKCS1_V15)
976 68 : case MBEDTLS_RSA_PKCS_V15:
977 68 : break;
978 : #endif
979 :
980 : #if defined(MBEDTLS_PKCS1_V21)
981 2 : case MBEDTLS_RSA_PKCS_V21:
982 2 : break;
983 : #endif
984 0 : default:
985 0 : return MBEDTLS_ERR_RSA_INVALID_PADDING;
986 : }
987 :
988 : #if defined(MBEDTLS_PKCS1_V21)
989 70 : if ((padding == MBEDTLS_RSA_PKCS_V21) &&
990 : (hash_id != MBEDTLS_MD_NONE)) {
991 : /* Just make sure this hash is supported in this build. */
992 2 : if (mbedtls_md_info_from_type(hash_id) == NULL) {
993 0 : return MBEDTLS_ERR_RSA_INVALID_PADDING;
994 : }
995 : }
996 : #endif /* MBEDTLS_PKCS1_V21 */
997 :
998 70 : ctx->padding = padding;
999 70 : ctx->hash_id = hash_id;
1000 :
1001 70 : return 0;
1002 : }
1003 :
1004 : /*
1005 : * Get padding mode of initialized RSA context
1006 : */
1007 0 : int mbedtls_rsa_get_padding_mode(const mbedtls_rsa_context *ctx)
1008 : {
1009 0 : return ctx->padding;
1010 : }
1011 :
1012 : /*
1013 : * Get hash identifier of mbedtls_md_type_t type
1014 : */
1015 0 : int mbedtls_rsa_get_md_alg(const mbedtls_rsa_context *ctx)
1016 : {
1017 0 : return ctx->hash_id;
1018 : }
1019 :
1020 : /*
1021 : * Get length in bits of RSA modulus
1022 : */
1023 603 : size_t mbedtls_rsa_get_bitlen(const mbedtls_rsa_context *ctx)
1024 : {
1025 603 : return mbedtls_mpi_bitlen(&ctx->N);
1026 : }
1027 :
1028 : /*
1029 : * Get length in bytes of RSA modulus
1030 : */
1031 384 : size_t mbedtls_rsa_get_len(const mbedtls_rsa_context *ctx)
1032 : {
1033 384 : return ctx->len;
1034 : }
1035 :
1036 : #if defined(MBEDTLS_GENPRIME)
1037 :
1038 : /*
1039 : * Generate an RSA keypair
1040 : *
1041 : * This generation method follows the RSA key pair generation procedure of
1042 : * FIPS 186-4 if 2^16 < exponent < 2^256 and nbits = 2048 or nbits = 3072.
1043 : */
1044 0 : int mbedtls_rsa_gen_key(mbedtls_rsa_context *ctx,
1045 : int (*f_rng)(void *, unsigned char *, size_t),
1046 : void *p_rng,
1047 : unsigned int nbits, int exponent)
1048 : {
1049 0 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1050 : mbedtls_mpi H;
1051 0 : int prime_quality = 0;
1052 :
1053 : /*
1054 : * If the modulus is 1024 bit long or shorter, then the security strength of
1055 : * the RSA algorithm is less than or equal to 80 bits and therefore an error
1056 : * rate of 2^-80 is sufficient.
1057 : */
1058 0 : if (nbits > 1024) {
1059 0 : prime_quality = MBEDTLS_MPI_GEN_PRIME_FLAG_LOW_ERR;
1060 : }
1061 :
1062 0 : mbedtls_mpi_init(&H);
1063 :
1064 0 : if (exponent < 3 || nbits % 2 != 0) {
1065 0 : ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1066 0 : goto cleanup;
1067 : }
1068 :
1069 0 : if (nbits < MBEDTLS_RSA_GEN_KEY_MIN_BITS) {
1070 0 : ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1071 0 : goto cleanup;
1072 : }
1073 :
1074 : /*
1075 : * find primes P and Q with Q < P so that:
1076 : * 1. |P-Q| > 2^( nbits / 2 - 100 )
1077 : * 2. GCD( E, (P-1)*(Q-1) ) == 1
1078 : * 3. E^-1 mod LCM(P-1, Q-1) > 2^( nbits / 2 )
1079 : */
1080 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&ctx->E, exponent));
1081 :
1082 : do {
1083 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_gen_prime(&ctx->P, nbits >> 1,
1084 : prime_quality, f_rng, p_rng));
1085 :
1086 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_gen_prime(&ctx->Q, nbits >> 1,
1087 : prime_quality, f_rng, p_rng));
1088 :
1089 : /* make sure the difference between p and q is not too small (FIPS 186-4 §B.3.3 step 5.4) */
1090 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mpi(&H, &ctx->P, &ctx->Q));
1091 0 : if (mbedtls_mpi_bitlen(&H) <= ((nbits >= 200) ? ((nbits >> 1) - 99) : 0)) {
1092 0 : continue;
1093 : }
1094 :
1095 : /* not required by any standards, but some users rely on the fact that P > Q */
1096 0 : if (H.s < 0) {
1097 0 : mbedtls_mpi_swap(&ctx->P, &ctx->Q);
1098 : }
1099 :
1100 : /* Compute D = E^-1 mod LCM(P-1, Q-1) (FIPS 186-4 §B.3.1 criterion 3(b))
1101 : * if it exists (FIPS 186-4 §B.3.1 criterion 2(a)) */
1102 0 : ret = mbedtls_rsa_deduce_private_exponent(&ctx->P, &ctx->Q, &ctx->E, &ctx->D);
1103 0 : if (ret == MBEDTLS_ERR_MPI_NOT_ACCEPTABLE) {
1104 0 : mbedtls_mpi_lset(&ctx->D, 0); /* needed for the next call */
1105 0 : continue;
1106 : }
1107 0 : if (ret != 0) {
1108 0 : goto cleanup;
1109 : }
1110 :
1111 : /* (FIPS 186-4 §B.3.1 criterion 3(a)) */
1112 0 : if (mbedtls_mpi_bitlen(&ctx->D) <= ((nbits + 1) / 2)) {
1113 0 : continue;
1114 : }
1115 :
1116 0 : break;
1117 : } while (1);
1118 :
1119 :
1120 : /* N = P * Q */
1121 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->N, &ctx->P, &ctx->Q));
1122 0 : ctx->len = mbedtls_mpi_size(&ctx->N);
1123 :
1124 : #if !defined(MBEDTLS_RSA_NO_CRT)
1125 : /*
1126 : * DP = D mod (P - 1)
1127 : * DQ = D mod (Q - 1)
1128 : * QP = Q^-1 mod P
1129 : */
1130 0 : MBEDTLS_MPI_CHK(mbedtls_rsa_deduce_crt(&ctx->P, &ctx->Q, &ctx->D,
1131 : &ctx->DP, &ctx->DQ, &ctx->QP));
1132 : #endif /* MBEDTLS_RSA_NO_CRT */
1133 :
1134 : /* Double-check */
1135 0 : MBEDTLS_MPI_CHK(mbedtls_rsa_check_privkey(ctx));
1136 :
1137 0 : cleanup:
1138 :
1139 0 : mbedtls_mpi_free(&H);
1140 :
1141 0 : if (ret != 0) {
1142 0 : mbedtls_rsa_free(ctx);
1143 :
1144 0 : if ((-ret & ~0x7f) == 0) {
1145 0 : ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_KEY_GEN_FAILED, ret);
1146 : }
1147 0 : return ret;
1148 : }
1149 :
1150 0 : return 0;
1151 : }
1152 :
1153 : #endif /* MBEDTLS_GENPRIME */
1154 :
1155 : /*
1156 : * Check a public RSA key
1157 : */
1158 1423 : int mbedtls_rsa_check_pubkey(const mbedtls_rsa_context *ctx)
1159 : {
1160 1423 : if (rsa_check_context(ctx, 0 /* public */, 0 /* no blinding */) != 0) {
1161 0 : return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
1162 : }
1163 :
1164 1423 : if (mbedtls_mpi_bitlen(&ctx->N) < 128) {
1165 0 : return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
1166 : }
1167 :
1168 2846 : if (mbedtls_mpi_get_bit(&ctx->E, 0) == 0 ||
1169 2846 : mbedtls_mpi_bitlen(&ctx->E) < 2 ||
1170 1423 : mbedtls_mpi_cmp_mpi(&ctx->E, &ctx->N) >= 0) {
1171 0 : return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
1172 : }
1173 :
1174 1423 : return 0;
1175 : }
1176 :
1177 : /*
1178 : * Check for the consistency of all fields in an RSA private key context
1179 : */
1180 0 : int mbedtls_rsa_check_privkey(const mbedtls_rsa_context *ctx)
1181 : {
1182 0 : if (mbedtls_rsa_check_pubkey(ctx) != 0 ||
1183 0 : rsa_check_context(ctx, 1 /* private */, 1 /* blinding */) != 0) {
1184 0 : return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
1185 : }
1186 :
1187 0 : if (mbedtls_rsa_validate_params(&ctx->N, &ctx->P, &ctx->Q,
1188 : &ctx->D, &ctx->E, NULL, NULL) != 0) {
1189 0 : return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
1190 : }
1191 :
1192 : #if !defined(MBEDTLS_RSA_NO_CRT)
1193 0 : else if (mbedtls_rsa_validate_crt(&ctx->P, &ctx->Q, &ctx->D,
1194 : &ctx->DP, &ctx->DQ, &ctx->QP) != 0) {
1195 0 : return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
1196 : }
1197 : #endif
1198 :
1199 0 : return 0;
1200 : }
1201 :
1202 : /*
1203 : * Check if contexts holding a public and private key match
1204 : */
1205 0 : int mbedtls_rsa_check_pub_priv(const mbedtls_rsa_context *pub,
1206 : const mbedtls_rsa_context *prv)
1207 : {
1208 0 : if (mbedtls_rsa_check_pubkey(pub) != 0 ||
1209 0 : mbedtls_rsa_check_privkey(prv) != 0) {
1210 0 : return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
1211 : }
1212 :
1213 0 : if (mbedtls_mpi_cmp_mpi(&pub->N, &prv->N) != 0 ||
1214 0 : mbedtls_mpi_cmp_mpi(&pub->E, &prv->E) != 0) {
1215 0 : return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
1216 : }
1217 :
1218 0 : return 0;
1219 : }
1220 :
1221 : /*
1222 : * Do an RSA public key operation
1223 : */
1224 346 : int mbedtls_rsa_public(mbedtls_rsa_context *ctx,
1225 : const unsigned char *input,
1226 : unsigned char *output)
1227 : {
1228 346 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1229 : size_t olen;
1230 : mbedtls_mpi T;
1231 :
1232 346 : if (rsa_check_context(ctx, 0 /* public */, 0 /* no blinding */)) {
1233 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1234 : }
1235 :
1236 346 : mbedtls_mpi_init(&T);
1237 :
1238 : #if defined(MBEDTLS_THREADING_C)
1239 : if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) {
1240 : return ret;
1241 : }
1242 : #endif
1243 :
1244 346 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&T, input, ctx->len));
1245 :
1246 346 : if (mbedtls_mpi_cmp_mpi(&T, &ctx->N) >= 0) {
1247 1 : ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
1248 1 : goto cleanup;
1249 : }
1250 :
1251 345 : olen = ctx->len;
1252 345 : MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod_unsafe(&T, &T, &ctx->E, &ctx->N, &ctx->RN));
1253 345 : MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&T, output, olen));
1254 :
1255 345 : cleanup:
1256 : #if defined(MBEDTLS_THREADING_C)
1257 : if (mbedtls_mutex_unlock(&ctx->mutex) != 0) {
1258 : return MBEDTLS_ERR_THREADING_MUTEX_ERROR;
1259 : }
1260 : #endif
1261 :
1262 346 : mbedtls_mpi_free(&T);
1263 :
1264 346 : if (ret != 0) {
1265 1 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_PUBLIC_FAILED, ret);
1266 : }
1267 :
1268 345 : return 0;
1269 : }
1270 :
1271 : /*
1272 : * Generate or update blinding values, see section 10 of:
1273 : * KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA,
1274 : * DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer
1275 : * Berlin Heidelberg, 1996. p. 104-113.
1276 : */
1277 38 : static int rsa_prepare_blinding(mbedtls_rsa_context *ctx,
1278 : int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
1279 : {
1280 38 : int ret, count = 0;
1281 : mbedtls_mpi R;
1282 :
1283 38 : mbedtls_mpi_init(&R);
1284 :
1285 38 : if (ctx->Vf.p != NULL) {
1286 : /* We already have blinding values, just update them by squaring */
1287 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vi, &ctx->Vi, &ctx->Vi));
1288 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vi, &ctx->Vi, &ctx->N));
1289 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vf, &ctx->Vf, &ctx->Vf));
1290 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vf, &ctx->Vf, &ctx->N));
1291 :
1292 0 : goto cleanup;
1293 : }
1294 :
1295 : /* Unblinding value: Vf = random number, invertible mod N */
1296 38 : mbedtls_mpi_lset(&R, 0);
1297 : do {
1298 38 : if (count++ > 10) {
1299 0 : ret = MBEDTLS_ERR_RSA_RNG_FAILED;
1300 0 : goto cleanup;
1301 : }
1302 :
1303 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_random(&ctx->Vf, 1, &ctx->N, f_rng, p_rng));
1304 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_gcd_modinv_odd(&R, &ctx->Vi, &ctx->Vf, &ctx->N));
1305 38 : } while (mbedtls_mpi_cmp_int(&R, 1) != 0);
1306 :
1307 : /* Blinding value: Vi = Vf^(-e) mod N
1308 : * (Vi already contains Vf^-1 at this point) */
1309 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->Vi, &ctx->Vi, &ctx->E, &ctx->N, &ctx->RN));
1310 :
1311 :
1312 38 : cleanup:
1313 38 : mbedtls_mpi_free(&R);
1314 :
1315 38 : return ret;
1316 : }
1317 :
1318 : /*
1319 : * Unblind
1320 : * T = T * Vf mod N
1321 : */
1322 38 : static int rsa_unblind(mbedtls_mpi *T, mbedtls_mpi *Vf, const mbedtls_mpi *N)
1323 : {
1324 38 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1325 38 : const mbedtls_mpi_uint mm = mbedtls_mpi_core_montmul_init(N->p);
1326 38 : const size_t nlimbs = N->n;
1327 38 : const size_t tlimbs = mbedtls_mpi_core_montmul_working_limbs(nlimbs);
1328 : mbedtls_mpi RR, M_T;
1329 :
1330 38 : mbedtls_mpi_init(&RR);
1331 38 : mbedtls_mpi_init(&M_T);
1332 :
1333 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_core_get_mont_r2_unsafe(&RR, N));
1334 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_grow(&M_T, tlimbs));
1335 :
1336 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_grow(T, nlimbs));
1337 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_grow(Vf, nlimbs));
1338 :
1339 : /* T = T * Vf mod N
1340 : * Reminder: montmul(A, B, N) = A * B * R^-1 mod N
1341 : * Usually both operands are multiplied by R mod N beforehand (by calling
1342 : * `to_mont_rep()` on them), yielding a result that's also * R mod N (aka
1343 : * "in the Montgomery domain"). Here we only multiply one operand by R mod
1344 : * N, so the result is directly what we want - no need to call
1345 : * `from_mont_rep()` on it. */
1346 38 : mbedtls_mpi_core_to_mont_rep(T->p, T->p, N->p, nlimbs, mm, RR.p, M_T.p);
1347 38 : mbedtls_mpi_core_montmul(T->p, T->p, Vf->p, nlimbs, N->p, nlimbs, mm, M_T.p);
1348 :
1349 38 : cleanup:
1350 :
1351 38 : mbedtls_mpi_free(&RR);
1352 38 : mbedtls_mpi_free(&M_T);
1353 :
1354 38 : return ret;
1355 : }
1356 :
1357 : /*
1358 : * Exponent blinding supposed to prevent side-channel attacks using multiple
1359 : * traces of measurements to recover the RSA key. The more collisions are there,
1360 : * the more bits of the key can be recovered. See [3].
1361 : *
1362 : * Collecting n collisions with m bit long blinding value requires 2^(m-m/n)
1363 : * observations on average.
1364 : *
1365 : * For example with 28 byte blinding to achieve 2 collisions the adversary has
1366 : * to make 2^112 observations on average.
1367 : *
1368 : * (With the currently (as of 2017 April) known best algorithms breaking 2048
1369 : * bit RSA requires approximately as much time as trying out 2^112 random keys.
1370 : * Thus in this sense with 28 byte blinding the security is not reduced by
1371 : * side-channel attacks like the one in [3])
1372 : *
1373 : * This countermeasure does not help if the key recovery is possible with a
1374 : * single trace.
1375 : */
1376 : #define RSA_EXPONENT_BLINDING 28
1377 :
1378 : /*
1379 : * Do an RSA private key operation
1380 : */
1381 38 : int mbedtls_rsa_private(mbedtls_rsa_context *ctx,
1382 : int (*f_rng)(void *, unsigned char *, size_t),
1383 : void *p_rng,
1384 : const unsigned char *input,
1385 : unsigned char *output)
1386 : {
1387 38 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1388 : size_t olen;
1389 :
1390 : /* Temporary holding the result */
1391 : mbedtls_mpi T;
1392 :
1393 : /* Temporaries holding P-1, Q-1 and the
1394 : * exponent blinding factor, respectively. */
1395 : mbedtls_mpi P1, Q1, R;
1396 :
1397 : #if !defined(MBEDTLS_RSA_NO_CRT)
1398 : /* Temporaries holding the results mod p resp. mod q. */
1399 : mbedtls_mpi TP, TQ;
1400 :
1401 : /* Temporaries holding the blinded exponents for
1402 : * the mod p resp. mod q computation (if used). */
1403 : mbedtls_mpi DP_blind, DQ_blind;
1404 : #else
1405 : /* Temporary holding the blinded exponent (if used). */
1406 : mbedtls_mpi D_blind;
1407 : #endif /* MBEDTLS_RSA_NO_CRT */
1408 :
1409 : /* Temporaries holding the initial input and the double
1410 : * checked result; should be the same in the end. */
1411 : mbedtls_mpi input_blinded, check_result_blinded;
1412 :
1413 38 : if (f_rng == NULL) {
1414 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1415 : }
1416 :
1417 38 : if (rsa_check_context(ctx, 1 /* private key checks */,
1418 : 1 /* blinding on */) != 0) {
1419 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1420 : }
1421 :
1422 : #if defined(MBEDTLS_THREADING_C)
1423 : if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) {
1424 : return ret;
1425 : }
1426 : #endif
1427 :
1428 : /* MPI Initialization */
1429 38 : mbedtls_mpi_init(&T);
1430 :
1431 38 : mbedtls_mpi_init(&P1);
1432 38 : mbedtls_mpi_init(&Q1);
1433 38 : mbedtls_mpi_init(&R);
1434 :
1435 : #if defined(MBEDTLS_RSA_NO_CRT)
1436 : mbedtls_mpi_init(&D_blind);
1437 : #else
1438 38 : mbedtls_mpi_init(&DP_blind);
1439 38 : mbedtls_mpi_init(&DQ_blind);
1440 : #endif
1441 :
1442 : #if !defined(MBEDTLS_RSA_NO_CRT)
1443 38 : mbedtls_mpi_init(&TP); mbedtls_mpi_init(&TQ);
1444 : #endif
1445 :
1446 38 : mbedtls_mpi_init(&input_blinded);
1447 38 : mbedtls_mpi_init(&check_result_blinded);
1448 :
1449 : /* End of MPI initialization */
1450 :
1451 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&T, input, ctx->len));
1452 38 : if (mbedtls_mpi_cmp_mpi(&T, &ctx->N) >= 0) {
1453 0 : ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
1454 0 : goto cleanup;
1455 : }
1456 :
1457 : /*
1458 : * Blinding
1459 : * T = T * Vi mod N
1460 : */
1461 38 : MBEDTLS_MPI_CHK(rsa_prepare_blinding(ctx, f_rng, p_rng));
1462 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&T, &T, &ctx->Vi));
1463 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&T, &T, &ctx->N));
1464 :
1465 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&input_blinded, &T));
1466 :
1467 : /*
1468 : * Exponent blinding
1469 : */
1470 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&P1, &ctx->P, 1));
1471 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&Q1, &ctx->Q, 1));
1472 :
1473 : #if defined(MBEDTLS_RSA_NO_CRT)
1474 : /*
1475 : * D_blind = ( P - 1 ) * ( Q - 1 ) * R + D
1476 : */
1477 : MBEDTLS_MPI_CHK(mbedtls_mpi_fill_random(&R, RSA_EXPONENT_BLINDING,
1478 : f_rng, p_rng));
1479 : MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&D_blind, &P1, &Q1));
1480 : MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&D_blind, &D_blind, &R));
1481 : MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&D_blind, &D_blind, &ctx->D));
1482 : #else
1483 : /*
1484 : * DP_blind = ( P - 1 ) * R + DP
1485 : */
1486 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_fill_random(&R, RSA_EXPONENT_BLINDING,
1487 : f_rng, p_rng));
1488 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&DP_blind, &P1, &R));
1489 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&DP_blind, &DP_blind,
1490 : &ctx->DP));
1491 :
1492 : /*
1493 : * DQ_blind = ( Q - 1 ) * R + DQ
1494 : */
1495 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_fill_random(&R, RSA_EXPONENT_BLINDING,
1496 : f_rng, p_rng));
1497 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&DQ_blind, &Q1, &R));
1498 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&DQ_blind, &DQ_blind,
1499 : &ctx->DQ));
1500 : #endif /* MBEDTLS_RSA_NO_CRT */
1501 :
1502 : #if defined(MBEDTLS_RSA_NO_CRT)
1503 : MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&T, &T, &D_blind, &ctx->N, &ctx->RN));
1504 : #else
1505 : /*
1506 : * Faster decryption using the CRT
1507 : *
1508 : * TP = input ^ dP mod P
1509 : * TQ = input ^ dQ mod Q
1510 : */
1511 :
1512 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&TP, &T, &DP_blind, &ctx->P, &ctx->RP));
1513 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&TQ, &T, &DQ_blind, &ctx->Q, &ctx->RQ));
1514 :
1515 : /*
1516 : * T = (TP - TQ) * (Q^-1 mod P) mod P
1517 : */
1518 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mpi(&T, &TP, &TQ));
1519 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&TP, &T, &ctx->QP));
1520 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&T, &TP, &ctx->P));
1521 :
1522 : /*
1523 : * T = TQ + T * Q
1524 : */
1525 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&TP, &T, &ctx->Q));
1526 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&T, &TQ, &TP));
1527 : #endif /* MBEDTLS_RSA_NO_CRT */
1528 :
1529 : /* Verify the result to prevent glitching attacks. */
1530 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&check_result_blinded, &T, &ctx->E,
1531 : &ctx->N, &ctx->RN));
1532 38 : if (mbedtls_mpi_cmp_mpi(&check_result_blinded, &input_blinded) != 0) {
1533 0 : ret = MBEDTLS_ERR_RSA_VERIFY_FAILED;
1534 0 : goto cleanup;
1535 : }
1536 :
1537 : /*
1538 : * Unblind
1539 : * T = T * Vf mod N
1540 : */
1541 38 : MBEDTLS_MPI_CHK(rsa_unblind(&T, &ctx->Vf, &ctx->N));
1542 :
1543 38 : olen = ctx->len;
1544 38 : MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&T, output, olen));
1545 :
1546 38 : cleanup:
1547 : #if defined(MBEDTLS_THREADING_C)
1548 : if (mbedtls_mutex_unlock(&ctx->mutex) != 0) {
1549 : return MBEDTLS_ERR_THREADING_MUTEX_ERROR;
1550 : }
1551 : #endif
1552 :
1553 38 : mbedtls_mpi_free(&P1);
1554 38 : mbedtls_mpi_free(&Q1);
1555 38 : mbedtls_mpi_free(&R);
1556 :
1557 : #if defined(MBEDTLS_RSA_NO_CRT)
1558 : mbedtls_mpi_free(&D_blind);
1559 : #else
1560 38 : mbedtls_mpi_free(&DP_blind);
1561 38 : mbedtls_mpi_free(&DQ_blind);
1562 : #endif
1563 :
1564 38 : mbedtls_mpi_free(&T);
1565 :
1566 : #if !defined(MBEDTLS_RSA_NO_CRT)
1567 38 : mbedtls_mpi_free(&TP); mbedtls_mpi_free(&TQ);
1568 : #endif
1569 :
1570 38 : mbedtls_mpi_free(&check_result_blinded);
1571 38 : mbedtls_mpi_free(&input_blinded);
1572 :
1573 38 : if (ret != 0 && ret >= -0x007f) {
1574 0 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_PRIVATE_FAILED, ret);
1575 : }
1576 :
1577 38 : return ret;
1578 : }
1579 :
1580 : #if defined(MBEDTLS_PKCS1_V21)
1581 : /**
1582 : * Generate and apply the MGF1 operation (from PKCS#1 v2.1) to a buffer.
1583 : *
1584 : * \param dst buffer to mask
1585 : * \param dlen length of destination buffer
1586 : * \param src source of the mask generation
1587 : * \param slen length of the source buffer
1588 : * \param md_alg message digest to use
1589 : */
1590 2 : static int mgf_mask(unsigned char *dst, size_t dlen, unsigned char *src,
1591 : size_t slen, mbedtls_md_type_t md_alg)
1592 : {
1593 : unsigned char counter[4];
1594 : unsigned char *p;
1595 : unsigned int hlen;
1596 : size_t i, use_len;
1597 : unsigned char mask[MBEDTLS_MD_MAX_SIZE];
1598 2 : int ret = 0;
1599 : const mbedtls_md_info_t *md_info;
1600 : mbedtls_md_context_t md_ctx;
1601 :
1602 2 : mbedtls_md_init(&md_ctx);
1603 2 : md_info = mbedtls_md_info_from_type(md_alg);
1604 2 : if (md_info == NULL) {
1605 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1606 : }
1607 :
1608 2 : mbedtls_md_init(&md_ctx);
1609 2 : if ((ret = mbedtls_md_setup(&md_ctx, md_info, 0)) != 0) {
1610 0 : goto exit;
1611 : }
1612 :
1613 2 : hlen = mbedtls_md_get_size(md_info);
1614 :
1615 2 : memset(mask, 0, sizeof(mask));
1616 2 : memset(counter, 0, 4);
1617 :
1618 : /* Generate and apply dbMask */
1619 2 : p = dst;
1620 :
1621 16 : while (dlen > 0) {
1622 14 : use_len = hlen;
1623 14 : if (dlen < hlen) {
1624 2 : use_len = dlen;
1625 : }
1626 :
1627 14 : if ((ret = mbedtls_md_starts(&md_ctx)) != 0) {
1628 0 : goto exit;
1629 : }
1630 14 : if ((ret = mbedtls_md_update(&md_ctx, src, slen)) != 0) {
1631 0 : goto exit;
1632 : }
1633 14 : if ((ret = mbedtls_md_update(&md_ctx, counter, 4)) != 0) {
1634 0 : goto exit;
1635 : }
1636 14 : if ((ret = mbedtls_md_finish(&md_ctx, mask)) != 0) {
1637 0 : goto exit;
1638 : }
1639 :
1640 460 : for (i = 0; i < use_len; ++i) {
1641 446 : *p++ ^= mask[i];
1642 : }
1643 :
1644 14 : counter[3]++;
1645 :
1646 14 : dlen -= use_len;
1647 : }
1648 :
1649 2 : exit:
1650 2 : mbedtls_platform_zeroize(mask, sizeof(mask));
1651 2 : mbedtls_md_free(&md_ctx);
1652 :
1653 2 : return ret;
1654 : }
1655 :
1656 : /**
1657 : * Generate Hash(M') as in RFC 8017 page 43 points 5 and 6.
1658 : *
1659 : * \param hash the input hash
1660 : * \param hlen length of the input hash
1661 : * \param salt the input salt
1662 : * \param slen length of the input salt
1663 : * \param out the output buffer - must be large enough for \p md_alg
1664 : * \param md_alg message digest to use
1665 : */
1666 2 : static int hash_mprime(const unsigned char *hash, size_t hlen,
1667 : const unsigned char *salt, size_t slen,
1668 : unsigned char *out, mbedtls_md_type_t md_alg)
1669 : {
1670 2 : const unsigned char zeros[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
1671 :
1672 : mbedtls_md_context_t md_ctx;
1673 2 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1674 :
1675 2 : const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type(md_alg);
1676 2 : if (md_info == NULL) {
1677 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1678 : }
1679 :
1680 2 : mbedtls_md_init(&md_ctx);
1681 2 : if ((ret = mbedtls_md_setup(&md_ctx, md_info, 0)) != 0) {
1682 0 : goto exit;
1683 : }
1684 2 : if ((ret = mbedtls_md_starts(&md_ctx)) != 0) {
1685 0 : goto exit;
1686 : }
1687 2 : if ((ret = mbedtls_md_update(&md_ctx, zeros, sizeof(zeros))) != 0) {
1688 0 : goto exit;
1689 : }
1690 2 : if ((ret = mbedtls_md_update(&md_ctx, hash, hlen)) != 0) {
1691 0 : goto exit;
1692 : }
1693 2 : if ((ret = mbedtls_md_update(&md_ctx, salt, slen)) != 0) {
1694 0 : goto exit;
1695 : }
1696 2 : if ((ret = mbedtls_md_finish(&md_ctx, out)) != 0) {
1697 0 : goto exit;
1698 : }
1699 :
1700 2 : exit:
1701 2 : mbedtls_md_free(&md_ctx);
1702 :
1703 2 : return ret;
1704 : }
1705 :
1706 : /**
1707 : * Compute a hash.
1708 : *
1709 : * \param md_alg algorithm to use
1710 : * \param input input message to hash
1711 : * \param ilen input length
1712 : * \param output the output buffer - must be large enough for \p md_alg
1713 : */
1714 0 : static int compute_hash(mbedtls_md_type_t md_alg,
1715 : const unsigned char *input, size_t ilen,
1716 : unsigned char *output)
1717 : {
1718 : const mbedtls_md_info_t *md_info;
1719 :
1720 0 : md_info = mbedtls_md_info_from_type(md_alg);
1721 0 : if (md_info == NULL) {
1722 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1723 : }
1724 :
1725 0 : return mbedtls_md(md_info, input, ilen, output);
1726 : }
1727 : #endif /* MBEDTLS_PKCS1_V21 */
1728 :
1729 : #if defined(MBEDTLS_PKCS1_V21)
1730 : /*
1731 : * Implementation of the PKCS#1 v2.1 RSAES-OAEP-ENCRYPT function
1732 : */
1733 0 : int mbedtls_rsa_rsaes_oaep_encrypt(mbedtls_rsa_context *ctx,
1734 : int (*f_rng)(void *, unsigned char *, size_t),
1735 : void *p_rng,
1736 : const unsigned char *label, size_t label_len,
1737 : size_t ilen,
1738 : const unsigned char *input,
1739 : unsigned char *output)
1740 : {
1741 : size_t olen;
1742 0 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1743 0 : unsigned char *p = output;
1744 : unsigned int hlen;
1745 :
1746 0 : if (f_rng == NULL) {
1747 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1748 : }
1749 :
1750 0 : hlen = mbedtls_md_get_size_from_type((mbedtls_md_type_t) ctx->hash_id);
1751 0 : if (hlen == 0) {
1752 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1753 : }
1754 :
1755 0 : olen = ctx->len;
1756 :
1757 : /* first comparison checks for overflow */
1758 0 : if (ilen + 2 * hlen + 2 < ilen || olen < ilen + 2 * hlen + 2) {
1759 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1760 : }
1761 :
1762 0 : memset(output, 0, olen);
1763 :
1764 0 : *p++ = 0;
1765 :
1766 : /* Generate a random octet string seed */
1767 0 : if ((ret = f_rng(p_rng, p, hlen)) != 0) {
1768 0 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_RNG_FAILED, ret);
1769 : }
1770 :
1771 0 : p += hlen;
1772 :
1773 : /* Construct DB */
1774 0 : ret = compute_hash((mbedtls_md_type_t) ctx->hash_id, label, label_len, p);
1775 0 : if (ret != 0) {
1776 0 : return ret;
1777 : }
1778 0 : p += hlen;
1779 0 : p += olen - 2 * hlen - 2 - ilen;
1780 0 : *p++ = 1;
1781 0 : if (ilen != 0) {
1782 0 : memcpy(p, input, ilen);
1783 : }
1784 :
1785 : /* maskedDB: Apply dbMask to DB */
1786 0 : if ((ret = mgf_mask(output + hlen + 1, olen - hlen - 1, output + 1, hlen,
1787 0 : (mbedtls_md_type_t) ctx->hash_id)) != 0) {
1788 0 : return ret;
1789 : }
1790 :
1791 : /* maskedSeed: Apply seedMask to seed */
1792 0 : if ((ret = mgf_mask(output + 1, hlen, output + hlen + 1, olen - hlen - 1,
1793 0 : (mbedtls_md_type_t) ctx->hash_id)) != 0) {
1794 0 : return ret;
1795 : }
1796 :
1797 0 : return mbedtls_rsa_public(ctx, output, output);
1798 : }
1799 : #endif /* MBEDTLS_PKCS1_V21 */
1800 :
1801 : #if defined(MBEDTLS_PKCS1_V15)
1802 : /*
1803 : * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-ENCRYPT function
1804 : */
1805 0 : int mbedtls_rsa_rsaes_pkcs1_v15_encrypt(mbedtls_rsa_context *ctx,
1806 : int (*f_rng)(void *, unsigned char *, size_t),
1807 : void *p_rng, size_t ilen,
1808 : const unsigned char *input,
1809 : unsigned char *output)
1810 : {
1811 : size_t nb_pad, olen;
1812 0 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1813 0 : unsigned char *p = output;
1814 :
1815 0 : olen = ctx->len;
1816 :
1817 : /* first comparison checks for overflow */
1818 0 : if (ilen + 11 < ilen || olen < ilen + 11) {
1819 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1820 : }
1821 :
1822 0 : nb_pad = olen - 3 - ilen;
1823 :
1824 0 : *p++ = 0;
1825 :
1826 0 : if (f_rng == NULL) {
1827 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1828 : }
1829 :
1830 0 : *p++ = MBEDTLS_RSA_CRYPT;
1831 :
1832 0 : while (nb_pad-- > 0) {
1833 0 : int rng_dl = 100;
1834 :
1835 : do {
1836 0 : ret = f_rng(p_rng, p, 1);
1837 0 : } while (*p == 0 && --rng_dl && ret == 0);
1838 :
1839 : /* Check if RNG failed to generate data */
1840 0 : if (rng_dl == 0 || ret != 0) {
1841 0 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_RNG_FAILED, ret);
1842 : }
1843 :
1844 0 : p++;
1845 : }
1846 :
1847 0 : *p++ = 0;
1848 0 : if (ilen != 0) {
1849 0 : memcpy(p, input, ilen);
1850 : }
1851 :
1852 0 : return mbedtls_rsa_public(ctx, output, output);
1853 : }
1854 : #endif /* MBEDTLS_PKCS1_V15 */
1855 :
1856 : /*
1857 : * Add the message padding, then do an RSA operation
1858 : */
1859 0 : int mbedtls_rsa_pkcs1_encrypt(mbedtls_rsa_context *ctx,
1860 : int (*f_rng)(void *, unsigned char *, size_t),
1861 : void *p_rng,
1862 : size_t ilen,
1863 : const unsigned char *input,
1864 : unsigned char *output)
1865 : {
1866 0 : switch (ctx->padding) {
1867 : #if defined(MBEDTLS_PKCS1_V15)
1868 0 : case MBEDTLS_RSA_PKCS_V15:
1869 0 : return mbedtls_rsa_rsaes_pkcs1_v15_encrypt(ctx, f_rng, p_rng,
1870 : ilen, input, output);
1871 : #endif
1872 :
1873 : #if defined(MBEDTLS_PKCS1_V21)
1874 0 : case MBEDTLS_RSA_PKCS_V21:
1875 0 : return mbedtls_rsa_rsaes_oaep_encrypt(ctx, f_rng, p_rng, NULL, 0,
1876 : ilen, input, output);
1877 : #endif
1878 :
1879 0 : default:
1880 0 : return MBEDTLS_ERR_RSA_INVALID_PADDING;
1881 : }
1882 : }
1883 :
1884 : #if defined(MBEDTLS_PKCS1_V21)
1885 : /*
1886 : * Implementation of the PKCS#1 v2.1 RSAES-OAEP-DECRYPT function
1887 : */
1888 0 : int mbedtls_rsa_rsaes_oaep_decrypt(mbedtls_rsa_context *ctx,
1889 : int (*f_rng)(void *, unsigned char *, size_t),
1890 : void *p_rng,
1891 : const unsigned char *label, size_t label_len,
1892 : size_t *olen,
1893 : const unsigned char *input,
1894 : unsigned char *output,
1895 : size_t output_max_len)
1896 : {
1897 0 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1898 : size_t ilen, i, pad_len;
1899 : unsigned char *p;
1900 : mbedtls_ct_condition_t bad, in_padding;
1901 : unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
1902 : unsigned char lhash[MBEDTLS_MD_MAX_SIZE];
1903 : unsigned int hlen;
1904 :
1905 : /*
1906 : * Parameters sanity checks
1907 : */
1908 0 : if (ctx->padding != MBEDTLS_RSA_PKCS_V21) {
1909 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1910 : }
1911 :
1912 0 : ilen = ctx->len;
1913 :
1914 0 : if (ilen < 16 || ilen > sizeof(buf)) {
1915 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1916 : }
1917 :
1918 0 : hlen = mbedtls_md_get_size_from_type((mbedtls_md_type_t) ctx->hash_id);
1919 0 : if (hlen == 0) {
1920 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1921 : }
1922 :
1923 : // checking for integer underflow
1924 0 : if (2 * hlen + 2 > ilen) {
1925 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
1926 : }
1927 :
1928 : /*
1929 : * RSA operation
1930 : */
1931 0 : ret = mbedtls_rsa_private(ctx, f_rng, p_rng, input, buf);
1932 :
1933 0 : if (ret != 0) {
1934 0 : goto cleanup;
1935 : }
1936 :
1937 : /*
1938 : * Unmask data and generate lHash
1939 : */
1940 : /* seed: Apply seedMask to maskedSeed */
1941 0 : if ((ret = mgf_mask(buf + 1, hlen, buf + hlen + 1, ilen - hlen - 1,
1942 0 : (mbedtls_md_type_t) ctx->hash_id)) != 0 ||
1943 : /* DB: Apply dbMask to maskedDB */
1944 0 : (ret = mgf_mask(buf + hlen + 1, ilen - hlen - 1, buf + 1, hlen,
1945 0 : (mbedtls_md_type_t) ctx->hash_id)) != 0) {
1946 0 : goto cleanup;
1947 : }
1948 :
1949 : /* Generate lHash */
1950 0 : ret = compute_hash((mbedtls_md_type_t) ctx->hash_id,
1951 : label, label_len, lhash);
1952 0 : if (ret != 0) {
1953 0 : goto cleanup;
1954 : }
1955 :
1956 : /*
1957 : * Check contents, in "constant-time"
1958 : */
1959 0 : p = buf;
1960 :
1961 0 : bad = mbedtls_ct_bool(*p++); /* First byte must be 0 */
1962 :
1963 0 : p += hlen; /* Skip seed */
1964 :
1965 : /* Check lHash */
1966 0 : bad = mbedtls_ct_bool_or(bad, mbedtls_ct_bool(mbedtls_ct_memcmp(lhash, p, hlen)));
1967 0 : p += hlen;
1968 :
1969 : /* Get zero-padding len, but always read till end of buffer
1970 : * (minus one, for the 01 byte) */
1971 0 : pad_len = 0;
1972 0 : in_padding = MBEDTLS_CT_TRUE;
1973 0 : for (i = 0; i < ilen - 2 * hlen - 2; i++) {
1974 0 : in_padding = mbedtls_ct_bool_and(in_padding, mbedtls_ct_uint_eq(p[i], 0));
1975 0 : pad_len += mbedtls_ct_uint_if_else_0(in_padding, 1);
1976 : }
1977 :
1978 0 : p += pad_len;
1979 0 : bad = mbedtls_ct_bool_or(bad, mbedtls_ct_uint_ne(*p++, 0x01));
1980 :
1981 : /*
1982 : * The only information "leaked" is whether the padding was correct or not
1983 : * (eg, no data is copied if it was not correct). This meets the
1984 : * recommendations in PKCS#1 v2.2: an opponent cannot distinguish between
1985 : * the different error conditions.
1986 : */
1987 0 : if (bad != MBEDTLS_CT_FALSE) {
1988 0 : ret = MBEDTLS_ERR_RSA_INVALID_PADDING;
1989 0 : goto cleanup;
1990 : }
1991 :
1992 0 : if (ilen - ((size_t) (p - buf)) > output_max_len) {
1993 0 : ret = MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE;
1994 0 : goto cleanup;
1995 : }
1996 :
1997 0 : *olen = ilen - ((size_t) (p - buf));
1998 0 : if (*olen != 0) {
1999 0 : memcpy(output, p, *olen);
2000 : }
2001 0 : ret = 0;
2002 :
2003 0 : cleanup:
2004 0 : mbedtls_platform_zeroize(buf, sizeof(buf));
2005 0 : mbedtls_platform_zeroize(lhash, sizeof(lhash));
2006 :
2007 0 : return ret;
2008 : }
2009 : #endif /* MBEDTLS_PKCS1_V21 */
2010 :
2011 : #if defined(MBEDTLS_PKCS1_V15)
2012 : /*
2013 : * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-DECRYPT function
2014 : */
2015 0 : int mbedtls_rsa_rsaes_pkcs1_v15_decrypt(mbedtls_rsa_context *ctx,
2016 : int (*f_rng)(void *, unsigned char *, size_t),
2017 : void *p_rng,
2018 : size_t *olen,
2019 : const unsigned char *input,
2020 : unsigned char *output,
2021 : size_t output_max_len)
2022 : {
2023 0 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2024 : size_t ilen;
2025 : unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
2026 :
2027 0 : ilen = ctx->len;
2028 :
2029 0 : if (ctx->padding != MBEDTLS_RSA_PKCS_V15) {
2030 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2031 : }
2032 :
2033 0 : if (ilen < 16 || ilen > sizeof(buf)) {
2034 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2035 : }
2036 :
2037 0 : ret = mbedtls_rsa_private(ctx, f_rng, p_rng, input, buf);
2038 :
2039 0 : if (ret != 0) {
2040 0 : goto cleanup;
2041 : }
2042 :
2043 0 : ret = mbedtls_ct_rsaes_pkcs1_v15_unpadding(buf, ilen,
2044 : output, output_max_len, olen);
2045 :
2046 0 : cleanup:
2047 0 : mbedtls_platform_zeroize(buf, sizeof(buf));
2048 :
2049 0 : return ret;
2050 : }
2051 : #endif /* MBEDTLS_PKCS1_V15 */
2052 :
2053 : /*
2054 : * Do an RSA operation, then remove the message padding
2055 : */
2056 0 : int mbedtls_rsa_pkcs1_decrypt(mbedtls_rsa_context *ctx,
2057 : int (*f_rng)(void *, unsigned char *, size_t),
2058 : void *p_rng,
2059 : size_t *olen,
2060 : const unsigned char *input,
2061 : unsigned char *output,
2062 : size_t output_max_len)
2063 : {
2064 0 : switch (ctx->padding) {
2065 : #if defined(MBEDTLS_PKCS1_V15)
2066 0 : case MBEDTLS_RSA_PKCS_V15:
2067 0 : return mbedtls_rsa_rsaes_pkcs1_v15_decrypt(ctx, f_rng, p_rng, olen,
2068 : input, output, output_max_len);
2069 : #endif
2070 :
2071 : #if defined(MBEDTLS_PKCS1_V21)
2072 0 : case MBEDTLS_RSA_PKCS_V21:
2073 0 : return mbedtls_rsa_rsaes_oaep_decrypt(ctx, f_rng, p_rng, NULL, 0,
2074 : olen, input, output,
2075 : output_max_len);
2076 : #endif
2077 :
2078 0 : default:
2079 0 : return MBEDTLS_ERR_RSA_INVALID_PADDING;
2080 : }
2081 : }
2082 :
2083 : #if defined(MBEDTLS_PKCS1_V21)
2084 1 : static int rsa_rsassa_pss_sign_no_mode_check(mbedtls_rsa_context *ctx,
2085 : int (*f_rng)(void *, unsigned char *, size_t),
2086 : void *p_rng,
2087 : mbedtls_md_type_t md_alg,
2088 : unsigned int hashlen,
2089 : const unsigned char *hash,
2090 : int saltlen,
2091 : unsigned char *sig)
2092 : {
2093 : size_t olen;
2094 1 : unsigned char *p = sig;
2095 1 : unsigned char *salt = NULL;
2096 1 : size_t slen, min_slen, hlen, offset = 0;
2097 1 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2098 : size_t msb;
2099 : mbedtls_md_type_t hash_id;
2100 :
2101 1 : if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) {
2102 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2103 : }
2104 :
2105 1 : if (f_rng == NULL) {
2106 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2107 : }
2108 :
2109 1 : olen = ctx->len;
2110 :
2111 1 : if (md_alg != MBEDTLS_MD_NONE) {
2112 : /* Gather length of hash to sign */
2113 1 : size_t exp_hashlen = mbedtls_md_get_size_from_type(md_alg);
2114 1 : if (exp_hashlen == 0) {
2115 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2116 : }
2117 :
2118 1 : if (hashlen != exp_hashlen) {
2119 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2120 : }
2121 : }
2122 :
2123 1 : hash_id = (mbedtls_md_type_t) ctx->hash_id;
2124 1 : if (hash_id == MBEDTLS_MD_NONE) {
2125 0 : hash_id = md_alg;
2126 : }
2127 1 : hlen = mbedtls_md_get_size_from_type(hash_id);
2128 1 : if (hlen == 0) {
2129 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2130 : }
2131 :
2132 1 : if (saltlen == MBEDTLS_RSA_SALT_LEN_ANY) {
2133 : /* Calculate the largest possible salt length, up to the hash size.
2134 : * Normally this is the hash length, which is the maximum salt length
2135 : * according to FIPS 185-4 §5.5 (e) and common practice. If there is not
2136 : * enough room, use the maximum salt length that fits. The constraint is
2137 : * that the hash length plus the salt length plus 2 bytes must be at most
2138 : * the key length. This complies with FIPS 186-4 §5.5 (e) and RFC 8017
2139 : * (PKCS#1 v2.2) §9.1.1 step 3. */
2140 0 : min_slen = hlen - 2;
2141 0 : if (olen < hlen + min_slen + 2) {
2142 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2143 0 : } else if (olen >= hlen + hlen + 2) {
2144 0 : slen = hlen;
2145 : } else {
2146 0 : slen = olen - hlen - 2;
2147 : }
2148 1 : } else if ((saltlen < 0) || (saltlen + hlen + 2 > olen)) {
2149 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2150 : } else {
2151 1 : slen = (size_t) saltlen;
2152 : }
2153 :
2154 1 : memset(sig, 0, olen);
2155 :
2156 : /* Note: EMSA-PSS encoding is over the length of N - 1 bits */
2157 1 : msb = mbedtls_mpi_bitlen(&ctx->N) - 1;
2158 1 : p += olen - hlen - slen - 2;
2159 1 : *p++ = 0x01;
2160 :
2161 : /* Generate salt of length slen in place in the encoded message */
2162 1 : salt = p;
2163 1 : if ((ret = f_rng(p_rng, salt, slen)) != 0) {
2164 0 : return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_RNG_FAILED, ret);
2165 : }
2166 :
2167 1 : p += slen;
2168 :
2169 : /* Generate H = Hash( M' ) */
2170 1 : ret = hash_mprime(hash, hashlen, salt, slen, p, hash_id);
2171 1 : if (ret != 0) {
2172 0 : return ret;
2173 : }
2174 :
2175 : /* Compensate for boundary condition when applying mask */
2176 1 : if (msb % 8 == 0) {
2177 0 : offset = 1;
2178 : }
2179 :
2180 : /* maskedDB: Apply dbMask to DB */
2181 1 : ret = mgf_mask(sig + offset, olen - hlen - 1 - offset, p, hlen, hash_id);
2182 1 : if (ret != 0) {
2183 0 : return ret;
2184 : }
2185 :
2186 1 : msb = mbedtls_mpi_bitlen(&ctx->N) - 1;
2187 1 : sig[0] &= 0xFF >> (olen * 8 - msb);
2188 :
2189 1 : p += hlen;
2190 1 : *p++ = 0xBC;
2191 :
2192 1 : return mbedtls_rsa_private(ctx, f_rng, p_rng, sig, sig);
2193 : }
2194 :
2195 1 : static int rsa_rsassa_pss_sign(mbedtls_rsa_context *ctx,
2196 : int (*f_rng)(void *, unsigned char *, size_t),
2197 : void *p_rng,
2198 : mbedtls_md_type_t md_alg,
2199 : unsigned int hashlen,
2200 : const unsigned char *hash,
2201 : int saltlen,
2202 : unsigned char *sig)
2203 : {
2204 1 : if (ctx->padding != MBEDTLS_RSA_PKCS_V21) {
2205 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2206 : }
2207 1 : if ((ctx->hash_id == MBEDTLS_MD_NONE) && (md_alg == MBEDTLS_MD_NONE)) {
2208 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2209 : }
2210 1 : return rsa_rsassa_pss_sign_no_mode_check(ctx, f_rng, p_rng, md_alg, hashlen, hash, saltlen,
2211 : sig);
2212 : }
2213 :
2214 0 : int mbedtls_rsa_rsassa_pss_sign_no_mode_check(mbedtls_rsa_context *ctx,
2215 : int (*f_rng)(void *, unsigned char *, size_t),
2216 : void *p_rng,
2217 : mbedtls_md_type_t md_alg,
2218 : unsigned int hashlen,
2219 : const unsigned char *hash,
2220 : unsigned char *sig)
2221 : {
2222 0 : return rsa_rsassa_pss_sign_no_mode_check(ctx, f_rng, p_rng, md_alg,
2223 : hashlen, hash, MBEDTLS_RSA_SALT_LEN_ANY, sig);
2224 : }
2225 :
2226 : /*
2227 : * Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function with
2228 : * the option to pass in the salt length.
2229 : */
2230 1 : int mbedtls_rsa_rsassa_pss_sign_ext(mbedtls_rsa_context *ctx,
2231 : int (*f_rng)(void *, unsigned char *, size_t),
2232 : void *p_rng,
2233 : mbedtls_md_type_t md_alg,
2234 : unsigned int hashlen,
2235 : const unsigned char *hash,
2236 : int saltlen,
2237 : unsigned char *sig)
2238 : {
2239 1 : return rsa_rsassa_pss_sign(ctx, f_rng, p_rng, md_alg,
2240 : hashlen, hash, saltlen, sig);
2241 : }
2242 :
2243 : /*
2244 : * Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function
2245 : */
2246 0 : int mbedtls_rsa_rsassa_pss_sign(mbedtls_rsa_context *ctx,
2247 : int (*f_rng)(void *, unsigned char *, size_t),
2248 : void *p_rng,
2249 : mbedtls_md_type_t md_alg,
2250 : unsigned int hashlen,
2251 : const unsigned char *hash,
2252 : unsigned char *sig)
2253 : {
2254 0 : return rsa_rsassa_pss_sign(ctx, f_rng, p_rng, md_alg,
2255 : hashlen, hash, MBEDTLS_RSA_SALT_LEN_ANY, sig);
2256 : }
2257 : #endif /* MBEDTLS_PKCS1_V21 */
2258 :
2259 : #if defined(MBEDTLS_PKCS1_V15)
2260 : /*
2261 : * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-V1_5-SIGN function
2262 : */
2263 :
2264 : /* Construct a PKCS v1.5 encoding of a hashed message
2265 : *
2266 : * This is used both for signature generation and verification.
2267 : *
2268 : * Parameters:
2269 : * - md_alg: Identifies the hash algorithm used to generate the given hash;
2270 : * MBEDTLS_MD_NONE if raw data is signed.
2271 : * - hashlen: Length of hash. Must match md_alg if that's not NONE.
2272 : * - hash: Buffer containing the hashed message or the raw data.
2273 : * - dst_len: Length of the encoded message.
2274 : * - dst: Buffer to hold the encoded message.
2275 : *
2276 : * Assumptions:
2277 : * - hash has size hashlen.
2278 : * - dst points to a buffer of size at least dst_len.
2279 : *
2280 : */
2281 345 : static int rsa_rsassa_pkcs1_v15_encode(mbedtls_md_type_t md_alg,
2282 : unsigned int hashlen,
2283 : const unsigned char *hash,
2284 : size_t dst_len,
2285 : unsigned char *dst)
2286 : {
2287 345 : size_t oid_size = 0;
2288 345 : size_t nb_pad = dst_len;
2289 345 : unsigned char *p = dst;
2290 345 : const char *oid = NULL;
2291 :
2292 : /* Are we signing hashed or raw data? */
2293 345 : if (md_alg != MBEDTLS_MD_NONE) {
2294 345 : unsigned char md_size = mbedtls_md_get_size_from_type(md_alg);
2295 345 : if (md_size == 0) {
2296 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2297 : }
2298 :
2299 345 : if (mbedtls_oid_get_oid_by_md(md_alg, &oid, &oid_size) != 0) {
2300 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2301 : }
2302 :
2303 345 : if (hashlen != md_size) {
2304 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2305 : }
2306 :
2307 : /* Double-check that 8 + hashlen + oid_size can be used as a
2308 : * 1-byte ASN.1 length encoding and that there's no overflow. */
2309 345 : if (8 + hashlen + oid_size >= 0x80 ||
2310 345 : 10 + hashlen < hashlen ||
2311 345 : 10 + hashlen + oid_size < 10 + hashlen) {
2312 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2313 : }
2314 :
2315 : /*
2316 : * Static bounds check:
2317 : * - Need 10 bytes for five tag-length pairs.
2318 : * (Insist on 1-byte length encodings to protect against variants of
2319 : * Bleichenbacher's forgery attack against lax PKCS#1v1.5 verification)
2320 : * - Need hashlen bytes for hash
2321 : * - Need oid_size bytes for hash alg OID.
2322 : */
2323 345 : if (nb_pad < 10 + hashlen + oid_size) {
2324 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2325 : }
2326 345 : nb_pad -= 10 + hashlen + oid_size;
2327 : } else {
2328 0 : if (nb_pad < hashlen) {
2329 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2330 : }
2331 :
2332 0 : nb_pad -= hashlen;
2333 : }
2334 :
2335 : /* Need space for signature header and padding delimiter (3 bytes),
2336 : * and 8 bytes for the minimal padding */
2337 345 : if (nb_pad < 3 + 8) {
2338 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2339 : }
2340 345 : nb_pad -= 3;
2341 :
2342 : /* Now nb_pad is the amount of memory to be filled
2343 : * with padding, and at least 8 bytes long. */
2344 :
2345 : /* Write signature header and padding */
2346 345 : *p++ = 0;
2347 345 : *p++ = MBEDTLS_RSA_SIGN;
2348 345 : memset(p, 0xFF, nb_pad);
2349 345 : p += nb_pad;
2350 345 : *p++ = 0;
2351 :
2352 : /* Are we signing raw data? */
2353 345 : if (md_alg == MBEDTLS_MD_NONE) {
2354 0 : memcpy(p, hash, hashlen);
2355 0 : return 0;
2356 : }
2357 :
2358 : /* Signing hashed data, add corresponding ASN.1 structure
2359 : *
2360 : * DigestInfo ::= SEQUENCE {
2361 : * digestAlgorithm DigestAlgorithmIdentifier,
2362 : * digest Digest }
2363 : * DigestAlgorithmIdentifier ::= AlgorithmIdentifier
2364 : * Digest ::= OCTET STRING
2365 : *
2366 : * Schematic:
2367 : * TAG-SEQ + LEN [ TAG-SEQ + LEN [ TAG-OID + LEN [ OID ]
2368 : * TAG-NULL + LEN [ NULL ] ]
2369 : * TAG-OCTET + LEN [ HASH ] ]
2370 : */
2371 345 : *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
2372 345 : *p++ = (unsigned char) (0x08 + oid_size + hashlen);
2373 345 : *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
2374 345 : *p++ = (unsigned char) (0x04 + oid_size);
2375 345 : *p++ = MBEDTLS_ASN1_OID;
2376 345 : *p++ = (unsigned char) oid_size;
2377 345 : memcpy(p, oid, oid_size);
2378 345 : p += oid_size;
2379 345 : *p++ = MBEDTLS_ASN1_NULL;
2380 345 : *p++ = 0x00;
2381 345 : *p++ = MBEDTLS_ASN1_OCTET_STRING;
2382 345 : *p++ = (unsigned char) hashlen;
2383 345 : memcpy(p, hash, hashlen);
2384 345 : p += hashlen;
2385 :
2386 : /* Just a sanity-check, should be automatic
2387 : * after the initial bounds check. */
2388 345 : if (p != dst + dst_len) {
2389 0 : mbedtls_platform_zeroize(dst, dst_len);
2390 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2391 : }
2392 :
2393 345 : return 0;
2394 : }
2395 :
2396 : /*
2397 : * Do an RSA operation to sign the message digest
2398 : */
2399 37 : int mbedtls_rsa_rsassa_pkcs1_v15_sign(mbedtls_rsa_context *ctx,
2400 : int (*f_rng)(void *, unsigned char *, size_t),
2401 : void *p_rng,
2402 : mbedtls_md_type_t md_alg,
2403 : unsigned int hashlen,
2404 : const unsigned char *hash,
2405 : unsigned char *sig)
2406 : {
2407 37 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2408 37 : unsigned char *sig_try = NULL, *verif = NULL;
2409 :
2410 37 : if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) {
2411 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2412 : }
2413 :
2414 37 : if (ctx->padding != MBEDTLS_RSA_PKCS_V15) {
2415 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2416 : }
2417 :
2418 : /*
2419 : * Prepare PKCS1-v1.5 encoding (padding and hash identifier)
2420 : */
2421 :
2422 37 : if ((ret = rsa_rsassa_pkcs1_v15_encode(md_alg, hashlen, hash,
2423 : ctx->len, sig)) != 0) {
2424 0 : return ret;
2425 : }
2426 :
2427 : /* Private key operation
2428 : *
2429 : * In order to prevent Lenstra's attack, make the signature in a
2430 : * temporary buffer and check it before returning it.
2431 : */
2432 :
2433 37 : sig_try = mbedtls_calloc(1, ctx->len);
2434 37 : if (sig_try == NULL) {
2435 0 : return MBEDTLS_ERR_MPI_ALLOC_FAILED;
2436 : }
2437 :
2438 37 : verif = mbedtls_calloc(1, ctx->len);
2439 37 : if (verif == NULL) {
2440 0 : mbedtls_free(sig_try);
2441 0 : return MBEDTLS_ERR_MPI_ALLOC_FAILED;
2442 : }
2443 :
2444 37 : MBEDTLS_MPI_CHK(mbedtls_rsa_private(ctx, f_rng, p_rng, sig, sig_try));
2445 37 : MBEDTLS_MPI_CHK(mbedtls_rsa_public(ctx, sig_try, verif));
2446 :
2447 37 : if (mbedtls_ct_memcmp(verif, sig, ctx->len) != 0) {
2448 0 : ret = MBEDTLS_ERR_RSA_PRIVATE_FAILED;
2449 0 : goto cleanup;
2450 : }
2451 :
2452 37 : memcpy(sig, sig_try, ctx->len);
2453 :
2454 37 : cleanup:
2455 37 : mbedtls_zeroize_and_free(sig_try, ctx->len);
2456 37 : mbedtls_zeroize_and_free(verif, ctx->len);
2457 :
2458 37 : if (ret != 0) {
2459 0 : memset(sig, '!', ctx->len);
2460 : }
2461 37 : return ret;
2462 : }
2463 : #endif /* MBEDTLS_PKCS1_V15 */
2464 :
2465 : /*
2466 : * Do an RSA operation to sign the message digest
2467 : */
2468 37 : int mbedtls_rsa_pkcs1_sign(mbedtls_rsa_context *ctx,
2469 : int (*f_rng)(void *, unsigned char *, size_t),
2470 : void *p_rng,
2471 : mbedtls_md_type_t md_alg,
2472 : unsigned int hashlen,
2473 : const unsigned char *hash,
2474 : unsigned char *sig)
2475 : {
2476 37 : if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) {
2477 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2478 : }
2479 :
2480 37 : switch (ctx->padding) {
2481 : #if defined(MBEDTLS_PKCS1_V15)
2482 37 : case MBEDTLS_RSA_PKCS_V15:
2483 37 : return mbedtls_rsa_rsassa_pkcs1_v15_sign(ctx, f_rng, p_rng,
2484 : md_alg, hashlen, hash, sig);
2485 : #endif
2486 :
2487 : #if defined(MBEDTLS_PKCS1_V21)
2488 0 : case MBEDTLS_RSA_PKCS_V21:
2489 0 : return mbedtls_rsa_rsassa_pss_sign(ctx, f_rng, p_rng, md_alg,
2490 : hashlen, hash, sig);
2491 : #endif
2492 :
2493 0 : default:
2494 0 : return MBEDTLS_ERR_RSA_INVALID_PADDING;
2495 : }
2496 : }
2497 :
2498 : #if defined(MBEDTLS_PKCS1_V21)
2499 : /*
2500 : * Implementation of the PKCS#1 v2.1 RSASSA-PSS-VERIFY function
2501 : */
2502 1 : int mbedtls_rsa_rsassa_pss_verify_ext(mbedtls_rsa_context *ctx,
2503 : mbedtls_md_type_t md_alg,
2504 : unsigned int hashlen,
2505 : const unsigned char *hash,
2506 : mbedtls_md_type_t mgf1_hash_id,
2507 : int expected_salt_len,
2508 : const unsigned char *sig)
2509 : {
2510 1 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2511 : size_t siglen;
2512 : unsigned char *p;
2513 : unsigned char *hash_start;
2514 : unsigned char result[MBEDTLS_MD_MAX_SIZE];
2515 : unsigned int hlen;
2516 : size_t observed_salt_len, msb;
2517 1 : unsigned char buf[MBEDTLS_MPI_MAX_SIZE] = { 0 };
2518 :
2519 1 : if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) {
2520 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2521 : }
2522 :
2523 1 : siglen = ctx->len;
2524 :
2525 1 : if (siglen < 16 || siglen > sizeof(buf)) {
2526 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2527 : }
2528 :
2529 1 : ret = mbedtls_rsa_public(ctx, sig, buf);
2530 :
2531 1 : if (ret != 0) {
2532 0 : return ret;
2533 : }
2534 :
2535 1 : p = buf;
2536 :
2537 1 : if (buf[siglen - 1] != 0xBC) {
2538 0 : return MBEDTLS_ERR_RSA_INVALID_PADDING;
2539 : }
2540 :
2541 1 : if (md_alg != MBEDTLS_MD_NONE) {
2542 : /* Gather length of hash to sign */
2543 1 : size_t exp_hashlen = mbedtls_md_get_size_from_type(md_alg);
2544 1 : if (exp_hashlen == 0) {
2545 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2546 : }
2547 :
2548 1 : if (hashlen != exp_hashlen) {
2549 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2550 : }
2551 : }
2552 :
2553 1 : hlen = mbedtls_md_get_size_from_type(mgf1_hash_id);
2554 1 : if (hlen == 0) {
2555 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2556 : }
2557 :
2558 : /*
2559 : * Note: EMSA-PSS verification is over the length of N - 1 bits
2560 : */
2561 1 : msb = mbedtls_mpi_bitlen(&ctx->N) - 1;
2562 :
2563 1 : if (buf[0] >> (8 - siglen * 8 + msb)) {
2564 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2565 : }
2566 :
2567 : /* Compensate for boundary condition when applying mask */
2568 1 : if (msb % 8 == 0) {
2569 0 : p++;
2570 0 : siglen -= 1;
2571 : }
2572 :
2573 1 : if (siglen < hlen + 2) {
2574 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2575 : }
2576 1 : hash_start = p + siglen - hlen - 1;
2577 :
2578 1 : ret = mgf_mask(p, siglen - hlen - 1, hash_start, hlen, mgf1_hash_id);
2579 1 : if (ret != 0) {
2580 0 : return ret;
2581 : }
2582 :
2583 1 : buf[0] &= 0xFF >> (siglen * 8 - msb);
2584 :
2585 223 : while (p < hash_start - 1 && *p == 0) {
2586 222 : p++;
2587 : }
2588 :
2589 1 : if (*p++ != 0x01) {
2590 0 : return MBEDTLS_ERR_RSA_INVALID_PADDING;
2591 : }
2592 :
2593 1 : observed_salt_len = (size_t) (hash_start - p);
2594 :
2595 1 : if (expected_salt_len != MBEDTLS_RSA_SALT_LEN_ANY &&
2596 1 : observed_salt_len != (size_t) expected_salt_len) {
2597 0 : return MBEDTLS_ERR_RSA_INVALID_PADDING;
2598 : }
2599 :
2600 : /*
2601 : * Generate H = Hash( M' )
2602 : */
2603 1 : ret = hash_mprime(hash, hashlen, p, observed_salt_len,
2604 : result, mgf1_hash_id);
2605 1 : if (ret != 0) {
2606 0 : return ret;
2607 : }
2608 :
2609 1 : if (memcmp(hash_start, result, hlen) != 0) {
2610 0 : return MBEDTLS_ERR_RSA_VERIFY_FAILED;
2611 : }
2612 :
2613 1 : return 0;
2614 : }
2615 :
2616 : /*
2617 : * Simplified PKCS#1 v2.1 RSASSA-PSS-VERIFY function
2618 : */
2619 0 : int mbedtls_rsa_rsassa_pss_verify(mbedtls_rsa_context *ctx,
2620 : mbedtls_md_type_t md_alg,
2621 : unsigned int hashlen,
2622 : const unsigned char *hash,
2623 : const unsigned char *sig)
2624 : {
2625 : mbedtls_md_type_t mgf1_hash_id;
2626 0 : if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) {
2627 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2628 : }
2629 :
2630 0 : mgf1_hash_id = (ctx->hash_id != MBEDTLS_MD_NONE)
2631 0 : ? (mbedtls_md_type_t) ctx->hash_id
2632 0 : : md_alg;
2633 :
2634 0 : return mbedtls_rsa_rsassa_pss_verify_ext(ctx,
2635 : md_alg, hashlen, hash,
2636 : mgf1_hash_id,
2637 : MBEDTLS_RSA_SALT_LEN_ANY,
2638 : sig);
2639 :
2640 : }
2641 : #endif /* MBEDTLS_PKCS1_V21 */
2642 :
2643 : #if defined(MBEDTLS_PKCS1_V15)
2644 : /*
2645 : * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-v1_5-VERIFY function
2646 : */
2647 308 : int mbedtls_rsa_rsassa_pkcs1_v15_verify(mbedtls_rsa_context *ctx,
2648 : mbedtls_md_type_t md_alg,
2649 : unsigned int hashlen,
2650 : const unsigned char *hash,
2651 : const unsigned char *sig)
2652 : {
2653 308 : int ret = 0;
2654 : size_t sig_len;
2655 308 : unsigned char *encoded = NULL, *encoded_expected = NULL;
2656 :
2657 308 : if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) {
2658 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2659 : }
2660 :
2661 308 : sig_len = ctx->len;
2662 :
2663 : /*
2664 : * Prepare expected PKCS1 v1.5 encoding of hash.
2665 : */
2666 :
2667 616 : if ((encoded = mbedtls_calloc(1, sig_len)) == NULL ||
2668 308 : (encoded_expected = mbedtls_calloc(1, sig_len)) == NULL) {
2669 0 : ret = MBEDTLS_ERR_MPI_ALLOC_FAILED;
2670 0 : goto cleanup;
2671 : }
2672 :
2673 308 : if ((ret = rsa_rsassa_pkcs1_v15_encode(md_alg, hashlen, hash, sig_len,
2674 : encoded_expected)) != 0) {
2675 0 : goto cleanup;
2676 : }
2677 :
2678 : /*
2679 : * Apply RSA primitive to get what should be PKCS1 encoded hash.
2680 : */
2681 :
2682 308 : ret = mbedtls_rsa_public(ctx, sig, encoded);
2683 308 : if (ret != 0) {
2684 1 : goto cleanup;
2685 : }
2686 :
2687 : /*
2688 : * Compare
2689 : */
2690 :
2691 307 : if ((ret = mbedtls_ct_memcmp(encoded, encoded_expected,
2692 : sig_len)) != 0) {
2693 7 : ret = MBEDTLS_ERR_RSA_VERIFY_FAILED;
2694 7 : goto cleanup;
2695 : }
2696 :
2697 300 : cleanup:
2698 :
2699 308 : if (encoded != NULL) {
2700 308 : mbedtls_zeroize_and_free(encoded, sig_len);
2701 : }
2702 :
2703 308 : if (encoded_expected != NULL) {
2704 308 : mbedtls_zeroize_and_free(encoded_expected, sig_len);
2705 : }
2706 :
2707 308 : return ret;
2708 : }
2709 : #endif /* MBEDTLS_PKCS1_V15 */
2710 :
2711 : /*
2712 : * Do an RSA operation and check the message digest
2713 : */
2714 308 : int mbedtls_rsa_pkcs1_verify(mbedtls_rsa_context *ctx,
2715 : mbedtls_md_type_t md_alg,
2716 : unsigned int hashlen,
2717 : const unsigned char *hash,
2718 : const unsigned char *sig)
2719 : {
2720 308 : if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) {
2721 0 : return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
2722 : }
2723 :
2724 308 : switch (ctx->padding) {
2725 : #if defined(MBEDTLS_PKCS1_V15)
2726 308 : case MBEDTLS_RSA_PKCS_V15:
2727 308 : return mbedtls_rsa_rsassa_pkcs1_v15_verify(ctx, md_alg,
2728 : hashlen, hash, sig);
2729 : #endif
2730 :
2731 : #if defined(MBEDTLS_PKCS1_V21)
2732 0 : case MBEDTLS_RSA_PKCS_V21:
2733 0 : return mbedtls_rsa_rsassa_pss_verify(ctx, md_alg,
2734 : hashlen, hash, sig);
2735 : #endif
2736 :
2737 0 : default:
2738 0 : return MBEDTLS_ERR_RSA_INVALID_PADDING;
2739 : }
2740 : }
2741 :
2742 : /*
2743 : * Copy the components of an RSA key
2744 : */
2745 138 : int mbedtls_rsa_copy(mbedtls_rsa_context *dst, const mbedtls_rsa_context *src)
2746 : {
2747 138 : int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2748 :
2749 138 : dst->len = src->len;
2750 :
2751 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->N, &src->N));
2752 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->E, &src->E));
2753 :
2754 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->D, &src->D));
2755 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->P, &src->P));
2756 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->Q, &src->Q));
2757 :
2758 : #if !defined(MBEDTLS_RSA_NO_CRT)
2759 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->DP, &src->DP));
2760 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->DQ, &src->DQ));
2761 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->QP, &src->QP));
2762 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->RP, &src->RP));
2763 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->RQ, &src->RQ));
2764 : #endif
2765 :
2766 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->RN, &src->RN));
2767 :
2768 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->Vi, &src->Vi));
2769 138 : MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->Vf, &src->Vf));
2770 :
2771 138 : dst->padding = src->padding;
2772 138 : dst->hash_id = src->hash_id;
2773 :
2774 138 : cleanup:
2775 138 : if (ret != 0) {
2776 0 : mbedtls_rsa_free(dst);
2777 : }
2778 :
2779 138 : return ret;
2780 : }
2781 :
2782 : /*
2783 : * Free the components of an RSA key
2784 : */
2785 1537 : void mbedtls_rsa_free(mbedtls_rsa_context *ctx)
2786 : {
2787 1537 : if (ctx == NULL) {
2788 0 : return;
2789 : }
2790 :
2791 1537 : mbedtls_mpi_free(&ctx->Vi);
2792 1537 : mbedtls_mpi_free(&ctx->Vf);
2793 1537 : mbedtls_mpi_free(&ctx->RN);
2794 1537 : mbedtls_mpi_free(&ctx->D);
2795 1537 : mbedtls_mpi_free(&ctx->Q);
2796 1537 : mbedtls_mpi_free(&ctx->P);
2797 1537 : mbedtls_mpi_free(&ctx->E);
2798 1537 : mbedtls_mpi_free(&ctx->N);
2799 :
2800 : #if !defined(MBEDTLS_RSA_NO_CRT)
2801 1537 : mbedtls_mpi_free(&ctx->RQ);
2802 1537 : mbedtls_mpi_free(&ctx->RP);
2803 1537 : mbedtls_mpi_free(&ctx->QP);
2804 1537 : mbedtls_mpi_free(&ctx->DQ);
2805 1537 : mbedtls_mpi_free(&ctx->DP);
2806 : #endif /* MBEDTLS_RSA_NO_CRT */
2807 :
2808 : #if defined(MBEDTLS_THREADING_C)
2809 : /* Free the mutex, but only if it hasn't been freed already. */
2810 : if (ctx->ver != 0) {
2811 : mbedtls_mutex_free(&ctx->mutex);
2812 : ctx->ver = 0;
2813 : }
2814 : #endif
2815 : }
2816 :
2817 : #endif /* !MBEDTLS_RSA_ALT */
2818 :
2819 : #if defined(MBEDTLS_SELF_TEST)
2820 :
2821 :
2822 : /*
2823 : * Example RSA-1024 keypair, for test purposes
2824 : */
2825 : #define KEY_LEN 128
2826 :
2827 : #define RSA_N "9292758453063D803DD603D5E777D788" \
2828 : "8ED1D5BF35786190FA2F23EBC0848AEA" \
2829 : "DDA92CA6C3D80B32C4D109BE0F36D6AE" \
2830 : "7130B9CED7ACDF54CFC7555AC14EEBAB" \
2831 : "93A89813FBF3C4F8066D2D800F7C38A8" \
2832 : "1AE31942917403FF4946B0A83D3D3E05" \
2833 : "EE57C6F5F5606FB5D4BC6CD34EE0801A" \
2834 : "5E94BB77B07507233A0BC7BAC8F90F79"
2835 :
2836 : #define RSA_E "10001"
2837 :
2838 : #define RSA_D "24BF6185468786FDD303083D25E64EFC" \
2839 : "66CA472BC44D253102F8B4A9D3BFA750" \
2840 : "91386C0077937FE33FA3252D28855837" \
2841 : "AE1B484A8A9A45F7EE8C0C634F99E8CD" \
2842 : "DF79C5CE07EE72C7F123142198164234" \
2843 : "CABB724CF78B8173B9F880FC86322407" \
2844 : "AF1FEDFDDE2BEB674CA15F3E81A1521E" \
2845 : "071513A1E85B5DFA031F21ECAE91A34D"
2846 :
2847 : #define RSA_P "C36D0EB7FCD285223CFB5AABA5BDA3D8" \
2848 : "2C01CAD19EA484A87EA4377637E75500" \
2849 : "FCB2005C5C7DD6EC4AC023CDA285D796" \
2850 : "C3D9E75E1EFC42488BB4F1D13AC30A57"
2851 :
2852 : #define RSA_Q "C000DF51A7C77AE8D7C7370C1FF55B69" \
2853 : "E211C2B9E5DB1ED0BF61D0D9899620F4" \
2854 : "910E4168387E3C30AA1E00C339A79508" \
2855 : "8452DD96A9A5EA5D9DCA68DA636032AF"
2856 :
2857 : #define PT_LEN 24
2858 : #define RSA_PT "\xAA\xBB\xCC\x03\x02\x01\x00\xFF\xFF\xFF\xFF\xFF" \
2859 : "\x11\x22\x33\x0A\x0B\x0C\xCC\xDD\xDD\xDD\xDD\xDD"
2860 :
2861 : #if defined(MBEDTLS_PKCS1_V15)
2862 0 : static int myrand(void *rng_state, unsigned char *output, size_t len)
2863 : {
2864 : #if !defined(__OpenBSD__) && !defined(__NetBSD__)
2865 : size_t i;
2866 :
2867 0 : if (rng_state != NULL) {
2868 0 : rng_state = NULL;
2869 : }
2870 :
2871 0 : for (i = 0; i < len; ++i) {
2872 0 : output[i] = rand();
2873 : }
2874 : #else
2875 : if (rng_state != NULL) {
2876 : rng_state = NULL;
2877 : }
2878 :
2879 : arc4random_buf(output, len);
2880 : #endif /* !OpenBSD && !NetBSD */
2881 :
2882 0 : return 0;
2883 : }
2884 : #endif /* MBEDTLS_PKCS1_V15 */
2885 :
2886 : /*
2887 : * Checkup routine
2888 : */
2889 0 : int mbedtls_rsa_self_test(int verbose)
2890 : {
2891 0 : int ret = 0;
2892 : #if defined(MBEDTLS_PKCS1_V15)
2893 : size_t len;
2894 : mbedtls_rsa_context rsa;
2895 : unsigned char rsa_plaintext[PT_LEN];
2896 : unsigned char rsa_decrypted[PT_LEN];
2897 : unsigned char rsa_ciphertext[KEY_LEN];
2898 : #if defined(MBEDTLS_MD_CAN_SHA1)
2899 : unsigned char sha1sum[20];
2900 : #endif
2901 :
2902 : mbedtls_mpi K;
2903 :
2904 0 : mbedtls_mpi_init(&K);
2905 0 : mbedtls_rsa_init(&rsa);
2906 :
2907 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&K, 16, RSA_N));
2908 0 : MBEDTLS_MPI_CHK(mbedtls_rsa_import(&rsa, &K, NULL, NULL, NULL, NULL));
2909 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&K, 16, RSA_P));
2910 0 : MBEDTLS_MPI_CHK(mbedtls_rsa_import(&rsa, NULL, &K, NULL, NULL, NULL));
2911 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&K, 16, RSA_Q));
2912 0 : MBEDTLS_MPI_CHK(mbedtls_rsa_import(&rsa, NULL, NULL, &K, NULL, NULL));
2913 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&K, 16, RSA_D));
2914 0 : MBEDTLS_MPI_CHK(mbedtls_rsa_import(&rsa, NULL, NULL, NULL, &K, NULL));
2915 0 : MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&K, 16, RSA_E));
2916 0 : MBEDTLS_MPI_CHK(mbedtls_rsa_import(&rsa, NULL, NULL, NULL, NULL, &K));
2917 :
2918 0 : MBEDTLS_MPI_CHK(mbedtls_rsa_complete(&rsa));
2919 :
2920 0 : if (verbose != 0) {
2921 0 : mbedtls_printf(" RSA key validation: ");
2922 : }
2923 :
2924 0 : if (mbedtls_rsa_check_pubkey(&rsa) != 0 ||
2925 0 : mbedtls_rsa_check_privkey(&rsa) != 0) {
2926 0 : if (verbose != 0) {
2927 0 : mbedtls_printf("failed\n");
2928 : }
2929 :
2930 0 : ret = 1;
2931 0 : goto cleanup;
2932 : }
2933 :
2934 0 : if (verbose != 0) {
2935 0 : mbedtls_printf("passed\n PKCS#1 encryption : ");
2936 : }
2937 :
2938 0 : memcpy(rsa_plaintext, RSA_PT, PT_LEN);
2939 :
2940 0 : if (mbedtls_rsa_pkcs1_encrypt(&rsa, myrand, NULL,
2941 : PT_LEN, rsa_plaintext,
2942 : rsa_ciphertext) != 0) {
2943 0 : if (verbose != 0) {
2944 0 : mbedtls_printf("failed\n");
2945 : }
2946 :
2947 0 : ret = 1;
2948 0 : goto cleanup;
2949 : }
2950 :
2951 0 : if (verbose != 0) {
2952 0 : mbedtls_printf("passed\n PKCS#1 decryption : ");
2953 : }
2954 :
2955 0 : if (mbedtls_rsa_pkcs1_decrypt(&rsa, myrand, NULL,
2956 : &len, rsa_ciphertext, rsa_decrypted,
2957 : sizeof(rsa_decrypted)) != 0) {
2958 0 : if (verbose != 0) {
2959 0 : mbedtls_printf("failed\n");
2960 : }
2961 :
2962 0 : ret = 1;
2963 0 : goto cleanup;
2964 : }
2965 :
2966 0 : if (memcmp(rsa_decrypted, rsa_plaintext, len) != 0) {
2967 0 : if (verbose != 0) {
2968 0 : mbedtls_printf("failed\n");
2969 : }
2970 :
2971 0 : ret = 1;
2972 0 : goto cleanup;
2973 : }
2974 :
2975 0 : if (verbose != 0) {
2976 0 : mbedtls_printf("passed\n");
2977 : }
2978 :
2979 : #if defined(MBEDTLS_MD_CAN_SHA1)
2980 : if (verbose != 0) {
2981 : mbedtls_printf(" PKCS#1 data sign : ");
2982 : }
2983 :
2984 : if (mbedtls_md(mbedtls_md_info_from_type(MBEDTLS_MD_SHA1),
2985 : rsa_plaintext, PT_LEN, sha1sum) != 0) {
2986 : if (verbose != 0) {
2987 : mbedtls_printf("failed\n");
2988 : }
2989 :
2990 : return 1;
2991 : }
2992 :
2993 : if (mbedtls_rsa_pkcs1_sign(&rsa, myrand, NULL,
2994 : MBEDTLS_MD_SHA1, 20,
2995 : sha1sum, rsa_ciphertext) != 0) {
2996 : if (verbose != 0) {
2997 : mbedtls_printf("failed\n");
2998 : }
2999 :
3000 : ret = 1;
3001 : goto cleanup;
3002 : }
3003 :
3004 : if (verbose != 0) {
3005 : mbedtls_printf("passed\n PKCS#1 sig. verify: ");
3006 : }
3007 :
3008 : if (mbedtls_rsa_pkcs1_verify(&rsa, MBEDTLS_MD_SHA1, 20,
3009 : sha1sum, rsa_ciphertext) != 0) {
3010 : if (verbose != 0) {
3011 : mbedtls_printf("failed\n");
3012 : }
3013 :
3014 : ret = 1;
3015 : goto cleanup;
3016 : }
3017 :
3018 : if (verbose != 0) {
3019 : mbedtls_printf("passed\n");
3020 : }
3021 : #endif /* MBEDTLS_MD_CAN_SHA1 */
3022 :
3023 0 : if (verbose != 0) {
3024 0 : mbedtls_printf("\n");
3025 : }
3026 :
3027 0 : cleanup:
3028 0 : mbedtls_mpi_free(&K);
3029 0 : mbedtls_rsa_free(&rsa);
3030 : #else /* MBEDTLS_PKCS1_V15 */
3031 : ((void) verbose);
3032 : #endif /* MBEDTLS_PKCS1_V15 */
3033 0 : return ret;
3034 : }
3035 :
3036 : #endif /* MBEDTLS_SELF_TEST */
3037 :
3038 : #endif /* MBEDTLS_RSA_C */
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