2 * The RSA public-key cryptosystem
4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
5 * SPDX-License-Identifier: Apache-2.0
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
19 * This file is part of mbed TLS (https://tls.mbed.org)
22 * The following sources were referenced in the design of this implementation
23 * of the RSA algorithm:
25 * [1] A method for obtaining digital signatures and public-key cryptosystems
26 * R Rivest, A Shamir, and L Adleman
27 * http://people.csail.mit.edu/rivest/pubs.html#RSA78
29 * [2] Handbook of Applied Cryptography - 1997, Chapter 8
30 * Menezes, van Oorschot and Vanstone
34 #if !defined(MBEDTLS_CONFIG_FILE)
35 #include "mbedtls/config.h"
37 #include MBEDTLS_CONFIG_FILE
40 #if defined(MBEDTLS_RSA_C)
42 #include "mbedtls/rsa.h"
43 #include "mbedtls/oid.h"
47 #if defined(MBEDTLS_PKCS1_V21)
48 #include "mbedtls/md.h"
51 #if defined(MBEDTLS_PKCS1_V15) && !defined(__OpenBSD__)
55 #if defined(MBEDTLS_PLATFORM_C)
56 #include "mbedtls/platform.h"
59 #define mbedtls_printf printf
60 #define mbedtls_calloc calloc
61 #define mbedtls_free free
65 * Initialize an RSA context
67 void mbedtls_rsa_init( mbedtls_rsa_context *ctx,
71 memset( ctx, 0, sizeof( mbedtls_rsa_context ) );
73 mbedtls_rsa_set_padding( ctx, padding, hash_id );
75 #if defined(MBEDTLS_THREADING_C)
76 mbedtls_mutex_init( &ctx->mutex );
81 * Set padding for an existing RSA context
83 void mbedtls_rsa_set_padding( mbedtls_rsa_context *ctx, int padding, int hash_id )
85 ctx->padding = padding;
86 ctx->hash_id = hash_id;
89 #if defined(MBEDTLS_GENPRIME)
92 * Generate an RSA keypair
94 int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
95 int (*f_rng)(void *, unsigned char *, size_t),
97 unsigned int nbits, int exponent )
100 mbedtls_mpi P1, Q1, H, G;
102 if( f_rng == NULL || nbits < 128 || exponent < 3 )
103 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
106 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
108 mbedtls_mpi_init( &P1 ); mbedtls_mpi_init( &Q1 );
109 mbedtls_mpi_init( &H ); mbedtls_mpi_init( &G );
112 * find primes P and Q with Q < P so that:
113 * GCD( E, (P-1)*(Q-1) ) == 1
115 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->E, exponent ) );
119 MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->P, nbits >> 1, 0,
122 MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->Q, nbits >> 1, 0,
125 if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) == 0 )
128 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P, &ctx->Q ) );
129 if( mbedtls_mpi_bitlen( &ctx->N ) != nbits )
132 if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) < 0 )
133 mbedtls_mpi_swap( &ctx->P, &ctx->Q );
135 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &P1, &ctx->P, 1 ) );
136 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &Q1, &ctx->Q, 1 ) );
137 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &P1, &Q1 ) );
138 MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->E, &H ) );
140 while( mbedtls_mpi_cmp_int( &G, 1 ) != 0 );
143 * D = E^-1 mod ((P-1)*(Q-1))
148 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->D , &ctx->E, &H ) );
149 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->DP, &ctx->D, &P1 ) );
150 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->DQ, &ctx->D, &Q1 ) );
151 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->QP, &ctx->Q, &ctx->P ) );
153 ctx->len = ( mbedtls_mpi_bitlen( &ctx->N ) + 7 ) >> 3;
157 mbedtls_mpi_free( &P1 ); mbedtls_mpi_free( &Q1 ); mbedtls_mpi_free( &H ); mbedtls_mpi_free( &G );
161 mbedtls_rsa_free( ctx );
162 return( MBEDTLS_ERR_RSA_KEY_GEN_FAILED + ret );
168 #endif /* MBEDTLS_GENPRIME */
171 * Check a public RSA key
173 int mbedtls_rsa_check_pubkey( const mbedtls_rsa_context *ctx )
175 if( !ctx->N.p || !ctx->E.p )
176 return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
178 if( ( ctx->N.p[0] & 1 ) == 0 ||
179 ( ctx->E.p[0] & 1 ) == 0 )
180 return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
182 if( mbedtls_mpi_bitlen( &ctx->N ) < 128 ||
183 mbedtls_mpi_bitlen( &ctx->N ) > MBEDTLS_MPI_MAX_BITS )
184 return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
186 if( mbedtls_mpi_bitlen( &ctx->E ) < 2 ||
187 mbedtls_mpi_cmp_mpi( &ctx->E, &ctx->N ) >= 0 )
188 return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
194 * Check a private RSA key
196 int mbedtls_rsa_check_privkey( const mbedtls_rsa_context *ctx )
199 mbedtls_mpi PQ, DE, P1, Q1, H, I, G, G2, L1, L2, DP, DQ, QP;
201 if( ( ret = mbedtls_rsa_check_pubkey( ctx ) ) != 0 )
204 if( !ctx->P.p || !ctx->Q.p || !ctx->D.p )
205 return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
207 mbedtls_mpi_init( &PQ ); mbedtls_mpi_init( &DE ); mbedtls_mpi_init( &P1 ); mbedtls_mpi_init( &Q1 );
208 mbedtls_mpi_init( &H ); mbedtls_mpi_init( &I ); mbedtls_mpi_init( &G ); mbedtls_mpi_init( &G2 );
209 mbedtls_mpi_init( &L1 ); mbedtls_mpi_init( &L2 ); mbedtls_mpi_init( &DP ); mbedtls_mpi_init( &DQ );
210 mbedtls_mpi_init( &QP );
212 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &PQ, &ctx->P, &ctx->Q ) );
213 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &DE, &ctx->D, &ctx->E ) );
214 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &P1, &ctx->P, 1 ) );
215 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &Q1, &ctx->Q, 1 ) );
216 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &P1, &Q1 ) );
217 MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->E, &H ) );
219 MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G2, &P1, &Q1 ) );
220 MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( &L1, &L2, &H, &G2 ) );
221 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &I, &DE, &L1 ) );
223 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &DP, &ctx->D, &P1 ) );
224 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &DQ, &ctx->D, &Q1 ) );
225 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &QP, &ctx->Q, &ctx->P ) );
227 * Check for a valid PKCS1v2 private key
229 if( mbedtls_mpi_cmp_mpi( &PQ, &ctx->N ) != 0 ||
230 mbedtls_mpi_cmp_mpi( &DP, &ctx->DP ) != 0 ||
231 mbedtls_mpi_cmp_mpi( &DQ, &ctx->DQ ) != 0 ||
232 mbedtls_mpi_cmp_mpi( &QP, &ctx->QP ) != 0 ||
233 mbedtls_mpi_cmp_int( &L2, 0 ) != 0 ||
234 mbedtls_mpi_cmp_int( &I, 1 ) != 0 ||
235 mbedtls_mpi_cmp_int( &G, 1 ) != 0 )
237 ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
241 mbedtls_mpi_free( &PQ ); mbedtls_mpi_free( &DE ); mbedtls_mpi_free( &P1 ); mbedtls_mpi_free( &Q1 );
242 mbedtls_mpi_free( &H ); mbedtls_mpi_free( &I ); mbedtls_mpi_free( &G ); mbedtls_mpi_free( &G2 );
243 mbedtls_mpi_free( &L1 ); mbedtls_mpi_free( &L2 ); mbedtls_mpi_free( &DP ); mbedtls_mpi_free( &DQ );
244 mbedtls_mpi_free( &QP );
246 if( ret == MBEDTLS_ERR_RSA_KEY_CHECK_FAILED )
250 return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED + ret );
256 * Check if contexts holding a public and private key match
258 int mbedtls_rsa_check_pub_priv( const mbedtls_rsa_context *pub, const mbedtls_rsa_context *prv )
260 if( mbedtls_rsa_check_pubkey( pub ) != 0 ||
261 mbedtls_rsa_check_privkey( prv ) != 0 )
263 return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
266 if( mbedtls_mpi_cmp_mpi( &pub->N, &prv->N ) != 0 ||
267 mbedtls_mpi_cmp_mpi( &pub->E, &prv->E ) != 0 )
269 return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
276 * Do an RSA public key operation
278 int mbedtls_rsa_public( mbedtls_rsa_context *ctx,
279 const unsigned char *input,
280 unsigned char *output )
286 mbedtls_mpi_init( &T );
288 #if defined(MBEDTLS_THREADING_C)
289 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
293 MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &T, input, ctx->len ) );
295 if( mbedtls_mpi_cmp_mpi( &T, &ctx->N ) >= 0 )
297 ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
302 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T, &T, &ctx->E, &ctx->N, &ctx->RN ) );
303 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &T, output, olen ) );
306 #if defined(MBEDTLS_THREADING_C)
307 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
308 return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
311 mbedtls_mpi_free( &T );
314 return( MBEDTLS_ERR_RSA_PUBLIC_FAILED + ret );
320 * Generate or update blinding values, see section 10 of:
321 * KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA,
322 * DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer
323 * Berlin Heidelberg, 1996. p. 104-113.
325 static int rsa_prepare_blinding( mbedtls_rsa_context *ctx,
326 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
330 if( ctx->Vf.p != NULL )
332 /* We already have blinding values, just update them by squaring */
333 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &ctx->Vi ) );
334 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->N ) );
335 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &ctx->Vf ) );
336 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->N ) );
341 /* Unblinding value: Vf = random number, invertible mod N */
344 return( MBEDTLS_ERR_RSA_RNG_FAILED );
346 MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->Vf, ctx->len - 1, f_rng, p_rng ) );
347 MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &ctx->Vi, &ctx->Vf, &ctx->N ) );
348 } while( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) != 0 );
350 /* Blinding value: Vi = Vf^(-e) mod N */
351 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->Vi, &ctx->Vf, &ctx->N ) );
352 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vi, &ctx->Vi, &ctx->E, &ctx->N, &ctx->RN ) );
360 * Do an RSA private key operation
362 int mbedtls_rsa_private( mbedtls_rsa_context *ctx,
363 int (*f_rng)(void *, unsigned char *, size_t),
365 const unsigned char *input,
366 unsigned char *output )
370 mbedtls_mpi T, T1, T2;
372 /* Make sure we have private key info, prevent possible misuse */
373 if( ctx->P.p == NULL || ctx->Q.p == NULL || ctx->D.p == NULL )
374 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
376 mbedtls_mpi_init( &T ); mbedtls_mpi_init( &T1 ); mbedtls_mpi_init( &T2 );
378 #if defined(MBEDTLS_THREADING_C)
379 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
383 MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &T, input, ctx->len ) );
384 if( mbedtls_mpi_cmp_mpi( &T, &ctx->N ) >= 0 )
386 ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
396 MBEDTLS_MPI_CHK( rsa_prepare_blinding( ctx, f_rng, p_rng ) );
397 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, &ctx->Vi ) );
398 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T, &ctx->N ) );
401 #if defined(MBEDTLS_RSA_NO_CRT)
402 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T, &T, &ctx->D, &ctx->N, &ctx->RN ) );
405 * faster decryption using the CRT
407 * T1 = input ^ dP mod P
408 * T2 = input ^ dQ mod Q
410 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T1, &T, &ctx->DP, &ctx->P, &ctx->RP ) );
411 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T2, &T, &ctx->DQ, &ctx->Q, &ctx->RQ ) );
414 * T = (T1 - T2) * (Q^-1 mod P) mod P
416 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &T, &T1, &T2 ) );
417 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T1, &T, &ctx->QP ) );
418 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T1, &ctx->P ) );
423 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T1, &T, &ctx->Q ) );
424 MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &T, &T2, &T1 ) );
425 #endif /* MBEDTLS_RSA_NO_CRT */
433 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, &ctx->Vf ) );
434 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T, &ctx->N ) );
438 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &T, output, olen ) );
441 #if defined(MBEDTLS_THREADING_C)
442 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
443 return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
446 mbedtls_mpi_free( &T ); mbedtls_mpi_free( &T1 ); mbedtls_mpi_free( &T2 );
449 return( MBEDTLS_ERR_RSA_PRIVATE_FAILED + ret );
454 #if defined(MBEDTLS_PKCS1_V21)
456 * Generate and apply the MGF1 operation (from PKCS#1 v2.1) to a buffer.
458 * \param dst buffer to mask
459 * \param dlen length of destination buffer
460 * \param src source of the mask generation
461 * \param slen length of the source buffer
462 * \param md_ctx message digest context to use
464 static void mgf_mask( unsigned char *dst, size_t dlen, unsigned char *src,
465 size_t slen, mbedtls_md_context_t *md_ctx )
467 unsigned char mask[MBEDTLS_MD_MAX_SIZE];
468 unsigned char counter[4];
473 memset( mask, 0, MBEDTLS_MD_MAX_SIZE );
474 memset( counter, 0, 4 );
476 hlen = mbedtls_md_get_size( md_ctx->md_info );
478 /* Generate and apply dbMask */
487 mbedtls_md_starts( md_ctx );
488 mbedtls_md_update( md_ctx, src, slen );
489 mbedtls_md_update( md_ctx, counter, 4 );
490 mbedtls_md_finish( md_ctx, mask );
492 for( i = 0; i < use_len; ++i )
500 #endif /* MBEDTLS_PKCS1_V21 */
502 #if defined(MBEDTLS_PKCS1_V21)
504 * Implementation of the PKCS#1 v2.1 RSAES-OAEP-ENCRYPT function
506 int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx,
507 int (*f_rng)(void *, unsigned char *, size_t),
510 const unsigned char *label, size_t label_len,
512 const unsigned char *input,
513 unsigned char *output )
517 unsigned char *p = output;
519 const mbedtls_md_info_t *md_info;
520 mbedtls_md_context_t md_ctx;
522 if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
523 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
526 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
528 md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id );
529 if( md_info == NULL )
530 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
533 hlen = mbedtls_md_get_size( md_info );
535 /* first comparison checks for overflow */
536 if( ilen + 2 * hlen + 2 < ilen || olen < ilen + 2 * hlen + 2 )
537 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
539 memset( output, 0, olen );
543 /* Generate a random octet string seed */
544 if( ( ret = f_rng( p_rng, p, hlen ) ) != 0 )
545 return( MBEDTLS_ERR_RSA_RNG_FAILED + ret );
550 mbedtls_md( md_info, label, label_len, p );
552 p += olen - 2 * hlen - 2 - ilen;
554 memcpy( p, input, ilen );
556 mbedtls_md_init( &md_ctx );
557 if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
559 mbedtls_md_free( &md_ctx );
563 /* maskedDB: Apply dbMask to DB */
564 mgf_mask( output + hlen + 1, olen - hlen - 1, output + 1, hlen,
567 /* maskedSeed: Apply seedMask to seed */
568 mgf_mask( output + 1, hlen, output + hlen + 1, olen - hlen - 1,
571 mbedtls_md_free( &md_ctx );
573 return( ( mode == MBEDTLS_RSA_PUBLIC )
574 ? mbedtls_rsa_public( ctx, output, output )
575 : mbedtls_rsa_private( ctx, f_rng, p_rng, output, output ) );
577 #endif /* MBEDTLS_PKCS1_V21 */
579 #if defined(MBEDTLS_PKCS1_V15)
581 * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-ENCRYPT function
583 int mbedtls_rsa_rsaes_pkcs1_v15_encrypt( mbedtls_rsa_context *ctx,
584 int (*f_rng)(void *, unsigned char *, size_t),
586 int mode, size_t ilen,
587 const unsigned char *input,
588 unsigned char *output )
592 unsigned char *p = output;
594 if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
595 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
597 // We don't check p_rng because it won't be dereferenced here
598 if( f_rng == NULL || input == NULL || output == NULL )
599 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
603 /* first comparison checks for overflow */
604 if( ilen + 11 < ilen || olen < ilen + 11 )
605 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
607 nb_pad = olen - 3 - ilen;
610 if( mode == MBEDTLS_RSA_PUBLIC )
612 *p++ = MBEDTLS_RSA_CRYPT;
614 while( nb_pad-- > 0 )
619 ret = f_rng( p_rng, p, 1 );
620 } while( *p == 0 && --rng_dl && ret == 0 );
622 /* Check if RNG failed to generate data */
623 if( rng_dl == 0 || ret != 0 )
624 return( MBEDTLS_ERR_RSA_RNG_FAILED + ret );
631 *p++ = MBEDTLS_RSA_SIGN;
633 while( nb_pad-- > 0 )
638 memcpy( p, input, ilen );
640 return( ( mode == MBEDTLS_RSA_PUBLIC )
641 ? mbedtls_rsa_public( ctx, output, output )
642 : mbedtls_rsa_private( ctx, f_rng, p_rng, output, output ) );
644 #endif /* MBEDTLS_PKCS1_V15 */
647 * Add the message padding, then do an RSA operation
649 int mbedtls_rsa_pkcs1_encrypt( mbedtls_rsa_context *ctx,
650 int (*f_rng)(void *, unsigned char *, size_t),
652 int mode, size_t ilen,
653 const unsigned char *input,
654 unsigned char *output )
656 switch( ctx->padding )
658 #if defined(MBEDTLS_PKCS1_V15)
659 case MBEDTLS_RSA_PKCS_V15:
660 return mbedtls_rsa_rsaes_pkcs1_v15_encrypt( ctx, f_rng, p_rng, mode, ilen,
664 #if defined(MBEDTLS_PKCS1_V21)
665 case MBEDTLS_RSA_PKCS_V21:
666 return mbedtls_rsa_rsaes_oaep_encrypt( ctx, f_rng, p_rng, mode, NULL, 0,
667 ilen, input, output );
671 return( MBEDTLS_ERR_RSA_INVALID_PADDING );
675 #if defined(MBEDTLS_PKCS1_V21)
677 * Implementation of the PKCS#1 v2.1 RSAES-OAEP-DECRYPT function
679 int mbedtls_rsa_rsaes_oaep_decrypt( mbedtls_rsa_context *ctx,
680 int (*f_rng)(void *, unsigned char *, size_t),
683 const unsigned char *label, size_t label_len,
685 const unsigned char *input,
686 unsigned char *output,
687 size_t output_max_len )
690 size_t ilen, i, pad_len;
691 unsigned char *p, bad, pad_done;
692 unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
693 unsigned char lhash[MBEDTLS_MD_MAX_SIZE];
695 const mbedtls_md_info_t *md_info;
696 mbedtls_md_context_t md_ctx;
699 * Parameters sanity checks
701 if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
702 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
706 if( ilen < 16 || ilen > sizeof( buf ) )
707 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
709 md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id );
710 if( md_info == NULL )
711 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
713 hlen = mbedtls_md_get_size( md_info );
715 // checking for integer underflow
716 if( 2 * hlen + 2 > ilen )
717 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
722 ret = ( mode == MBEDTLS_RSA_PUBLIC )
723 ? mbedtls_rsa_public( ctx, input, buf )
724 : mbedtls_rsa_private( ctx, f_rng, p_rng, input, buf );
730 * Unmask data and generate lHash
732 mbedtls_md_init( &md_ctx );
733 if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
735 mbedtls_md_free( &md_ctx );
741 mbedtls_md( md_info, label, label_len, lhash );
743 /* seed: Apply seedMask to maskedSeed */
744 mgf_mask( buf + 1, hlen, buf + hlen + 1, ilen - hlen - 1,
747 /* DB: Apply dbMask to maskedDB */
748 mgf_mask( buf + hlen + 1, ilen - hlen - 1, buf + 1, hlen,
751 mbedtls_md_free( &md_ctx );
754 * Check contents, in "constant-time"
759 bad |= *p++; /* First byte must be 0 */
761 p += hlen; /* Skip seed */
764 for( i = 0; i < hlen; i++ )
765 bad |= lhash[i] ^ *p++;
767 /* Get zero-padding len, but always read till end of buffer
768 * (minus one, for the 01 byte) */
771 for( i = 0; i < ilen - 2 * hlen - 2; i++ )
774 pad_len += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1;
781 * The only information "leaked" is whether the padding was correct or not
782 * (eg, no data is copied if it was not correct). This meets the
783 * recommendations in PKCS#1 v2.2: an opponent cannot distinguish between
784 * the different error conditions.
787 return( MBEDTLS_ERR_RSA_INVALID_PADDING );
789 if( ilen - ( p - buf ) > output_max_len )
790 return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE );
792 *olen = ilen - (p - buf);
793 memcpy( output, p, *olen );
797 #endif /* MBEDTLS_PKCS1_V21 */
799 #if defined(MBEDTLS_PKCS1_V15)
801 * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-DECRYPT function
803 int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
804 int (*f_rng)(void *, unsigned char *, size_t),
806 int mode, size_t *olen,
807 const unsigned char *input,
808 unsigned char *output,
809 size_t output_max_len)
812 size_t ilen, pad_count = 0, i;
813 unsigned char *p, bad, pad_done = 0;
814 unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
816 if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
817 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
821 if( ilen < 16 || ilen > sizeof( buf ) )
822 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
824 ret = ( mode == MBEDTLS_RSA_PUBLIC )
825 ? mbedtls_rsa_public( ctx, input, buf )
826 : mbedtls_rsa_private( ctx, f_rng, p_rng, input, buf );
835 * Check and get padding len in "constant-time"
837 bad |= *p++; /* First byte must be 0 */
839 /* This test does not depend on secret data */
840 if( mode == MBEDTLS_RSA_PRIVATE )
842 bad |= *p++ ^ MBEDTLS_RSA_CRYPT;
844 /* Get padding len, but always read till end of buffer
845 * (minus one, for the 00 byte) */
846 for( i = 0; i < ilen - 3; i++ )
848 pad_done |= ((p[i] | (unsigned char)-p[i]) >> 7) ^ 1;
849 pad_count += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1;
853 bad |= *p++; /* Must be zero */
857 bad |= *p++ ^ MBEDTLS_RSA_SIGN;
859 /* Get padding len, but always read till end of buffer
860 * (minus one, for the 00 byte) */
861 for( i = 0; i < ilen - 3; i++ )
863 pad_done |= ( p[i] != 0xFF );
864 pad_count += ( pad_done == 0 );
868 bad |= *p++; /* Must be zero */
871 bad |= ( pad_count < 8 );
874 return( MBEDTLS_ERR_RSA_INVALID_PADDING );
876 if( ilen - ( p - buf ) > output_max_len )
877 return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE );
879 *olen = ilen - (p - buf);
880 memcpy( output, p, *olen );
884 #endif /* MBEDTLS_PKCS1_V15 */
887 * Do an RSA operation, then remove the message padding
889 int mbedtls_rsa_pkcs1_decrypt( mbedtls_rsa_context *ctx,
890 int (*f_rng)(void *, unsigned char *, size_t),
892 int mode, size_t *olen,
893 const unsigned char *input,
894 unsigned char *output,
895 size_t output_max_len)
897 switch( ctx->padding )
899 #if defined(MBEDTLS_PKCS1_V15)
900 case MBEDTLS_RSA_PKCS_V15:
901 return mbedtls_rsa_rsaes_pkcs1_v15_decrypt( ctx, f_rng, p_rng, mode, olen,
902 input, output, output_max_len );
905 #if defined(MBEDTLS_PKCS1_V21)
906 case MBEDTLS_RSA_PKCS_V21:
907 return mbedtls_rsa_rsaes_oaep_decrypt( ctx, f_rng, p_rng, mode, NULL, 0,
913 return( MBEDTLS_ERR_RSA_INVALID_PADDING );
917 #if defined(MBEDTLS_PKCS1_V21)
919 * Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function
921 int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
922 int (*f_rng)(void *, unsigned char *, size_t),
925 mbedtls_md_type_t md_alg,
926 unsigned int hashlen,
927 const unsigned char *hash,
931 unsigned char *p = sig;
932 unsigned char salt[MBEDTLS_MD_MAX_SIZE];
933 unsigned int slen, hlen, offset = 0;
936 const mbedtls_md_info_t *md_info;
937 mbedtls_md_context_t md_ctx;
939 if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
940 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
943 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
947 if( md_alg != MBEDTLS_MD_NONE )
949 /* Gather length of hash to sign */
950 md_info = mbedtls_md_info_from_type( md_alg );
951 if( md_info == NULL )
952 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
954 hashlen = mbedtls_md_get_size( md_info );
957 md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id );
958 if( md_info == NULL )
959 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
961 hlen = mbedtls_md_get_size( md_info );
964 if( olen < hlen + slen + 2 )
965 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
967 memset( sig, 0, olen );
969 /* Generate salt of length slen */
970 if( ( ret = f_rng( p_rng, salt, slen ) ) != 0 )
971 return( MBEDTLS_ERR_RSA_RNG_FAILED + ret );
973 /* Note: EMSA-PSS encoding is over the length of N - 1 bits */
974 msb = mbedtls_mpi_bitlen( &ctx->N ) - 1;
975 p += olen - hlen * 2 - 2;
977 memcpy( p, salt, slen );
980 mbedtls_md_init( &md_ctx );
981 if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
983 mbedtls_md_free( &md_ctx );
987 /* Generate H = Hash( M' ) */
988 mbedtls_md_starts( &md_ctx );
989 mbedtls_md_update( &md_ctx, p, 8 );
990 mbedtls_md_update( &md_ctx, hash, hashlen );
991 mbedtls_md_update( &md_ctx, salt, slen );
992 mbedtls_md_finish( &md_ctx, p );
994 /* Compensate for boundary condition when applying mask */
998 /* maskedDB: Apply dbMask to DB */
999 mgf_mask( sig + offset, olen - hlen - 1 - offset, p, hlen, &md_ctx );
1001 mbedtls_md_free( &md_ctx );
1003 msb = mbedtls_mpi_bitlen( &ctx->N ) - 1;
1004 sig[0] &= 0xFF >> ( olen * 8 - msb );
1009 return( ( mode == MBEDTLS_RSA_PUBLIC )
1010 ? mbedtls_rsa_public( ctx, sig, sig )
1011 : mbedtls_rsa_private( ctx, f_rng, p_rng, sig, sig ) );
1013 #endif /* MBEDTLS_PKCS1_V21 */
1015 #if defined(MBEDTLS_PKCS1_V15)
1017 * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-V1_5-SIGN function
1020 * Do an RSA operation to sign the message digest
1022 int mbedtls_rsa_rsassa_pkcs1_v15_sign( mbedtls_rsa_context *ctx,
1023 int (*f_rng)(void *, unsigned char *, size_t),
1026 mbedtls_md_type_t md_alg,
1027 unsigned int hashlen,
1028 const unsigned char *hash,
1029 unsigned char *sig )
1031 size_t nb_pad, olen, oid_size = 0;
1032 unsigned char *p = sig;
1033 const char *oid = NULL;
1034 unsigned char *sig_try = NULL, *verif = NULL;
1037 volatile unsigned char diff_no_optimize;
1040 if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
1041 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1046 if( md_alg != MBEDTLS_MD_NONE )
1048 const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( md_alg );
1049 if( md_info == NULL )
1050 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1052 if( mbedtls_oid_get_oid_by_md( md_alg, &oid, &oid_size ) != 0 )
1053 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1055 nb_pad -= 10 + oid_size;
1057 hashlen = mbedtls_md_get_size( md_info );
1062 if( ( nb_pad < 8 ) || ( nb_pad > olen ) )
1063 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1066 *p++ = MBEDTLS_RSA_SIGN;
1067 memset( p, 0xFF, nb_pad );
1071 if( md_alg == MBEDTLS_MD_NONE )
1073 memcpy( p, hash, hashlen );
1078 * DigestInfo ::= SEQUENCE {
1079 * digestAlgorithm DigestAlgorithmIdentifier,
1082 * DigestAlgorithmIdentifier ::= AlgorithmIdentifier
1084 * Digest ::= OCTET STRING
1086 *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
1087 *p++ = (unsigned char) ( 0x08 + oid_size + hashlen );
1088 *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
1089 *p++ = (unsigned char) ( 0x04 + oid_size );
1090 *p++ = MBEDTLS_ASN1_OID;
1091 *p++ = oid_size & 0xFF;
1092 memcpy( p, oid, oid_size );
1094 *p++ = MBEDTLS_ASN1_NULL;
1096 *p++ = MBEDTLS_ASN1_OCTET_STRING;
1098 memcpy( p, hash, hashlen );
1101 if( mode == MBEDTLS_RSA_PUBLIC )
1102 return( mbedtls_rsa_public( ctx, sig, sig ) );
1105 * In order to prevent Lenstra's attack, make the signature in a
1106 * temporary buffer and check it before returning it.
1108 sig_try = mbedtls_calloc( 1, ctx->len );
1109 if( sig_try == NULL )
1110 return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
1112 verif = mbedtls_calloc( 1, ctx->len );
1115 mbedtls_free( sig_try );
1116 return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
1119 MBEDTLS_MPI_CHK( mbedtls_rsa_private( ctx, f_rng, p_rng, sig, sig_try ) );
1120 MBEDTLS_MPI_CHK( mbedtls_rsa_public( ctx, sig_try, verif ) );
1122 /* Compare in constant time just in case */
1123 for( diff = 0, i = 0; i < ctx->len; i++ )
1124 diff |= verif[i] ^ sig[i];
1125 diff_no_optimize = diff;
1127 if( diff_no_optimize != 0 )
1129 ret = MBEDTLS_ERR_RSA_PRIVATE_FAILED;
1133 memcpy( sig, sig_try, ctx->len );
1136 mbedtls_free( sig_try );
1137 mbedtls_free( verif );
1141 #endif /* MBEDTLS_PKCS1_V15 */
1144 * Do an RSA operation to sign the message digest
1146 int mbedtls_rsa_pkcs1_sign( mbedtls_rsa_context *ctx,
1147 int (*f_rng)(void *, unsigned char *, size_t),
1150 mbedtls_md_type_t md_alg,
1151 unsigned int hashlen,
1152 const unsigned char *hash,
1153 unsigned char *sig )
1155 switch( ctx->padding )
1157 #if defined(MBEDTLS_PKCS1_V15)
1158 case MBEDTLS_RSA_PKCS_V15:
1159 return mbedtls_rsa_rsassa_pkcs1_v15_sign( ctx, f_rng, p_rng, mode, md_alg,
1160 hashlen, hash, sig );
1163 #if defined(MBEDTLS_PKCS1_V21)
1164 case MBEDTLS_RSA_PKCS_V21:
1165 return mbedtls_rsa_rsassa_pss_sign( ctx, f_rng, p_rng, mode, md_alg,
1166 hashlen, hash, sig );
1170 return( MBEDTLS_ERR_RSA_INVALID_PADDING );
1174 #if defined(MBEDTLS_PKCS1_V21)
1176 * Implementation of the PKCS#1 v2.1 RSASSA-PSS-VERIFY function
1178 int mbedtls_rsa_rsassa_pss_verify_ext( mbedtls_rsa_context *ctx,
1179 int (*f_rng)(void *, unsigned char *, size_t),
1182 mbedtls_md_type_t md_alg,
1183 unsigned int hashlen,
1184 const unsigned char *hash,
1185 mbedtls_md_type_t mgf1_hash_id,
1186 int expected_salt_len,
1187 const unsigned char *sig )
1192 unsigned char *hash_start;
1193 unsigned char result[MBEDTLS_MD_MAX_SIZE];
1194 unsigned char zeros[8];
1196 size_t observed_salt_len, msb;
1197 const mbedtls_md_info_t *md_info;
1198 mbedtls_md_context_t md_ctx;
1199 unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
1201 if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
1202 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1206 if( siglen < 16 || siglen > sizeof( buf ) )
1207 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1209 ret = ( mode == MBEDTLS_RSA_PUBLIC )
1210 ? mbedtls_rsa_public( ctx, sig, buf )
1211 : mbedtls_rsa_private( ctx, f_rng, p_rng, sig, buf );
1218 if( buf[siglen - 1] != 0xBC )
1219 return( MBEDTLS_ERR_RSA_INVALID_PADDING );
1221 if( md_alg != MBEDTLS_MD_NONE )
1223 /* Gather length of hash to sign */
1224 md_info = mbedtls_md_info_from_type( md_alg );
1225 if( md_info == NULL )
1226 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1228 hashlen = mbedtls_md_get_size( md_info );
1231 md_info = mbedtls_md_info_from_type( mgf1_hash_id );
1232 if( md_info == NULL )
1233 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1235 hlen = mbedtls_md_get_size( md_info );
1237 memset( zeros, 0, 8 );
1240 * Note: EMSA-PSS verification is over the length of N - 1 bits
1242 msb = mbedtls_mpi_bitlen( &ctx->N ) - 1;
1244 /* Compensate for boundary condition when applying mask */
1251 if( buf[0] >> ( 8 - siglen * 8 + msb ) )
1252 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1254 if( siglen < hlen + 2 )
1255 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1256 hash_start = p + siglen - hlen - 1;
1258 mbedtls_md_init( &md_ctx );
1259 if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
1261 mbedtls_md_free( &md_ctx );
1265 mgf_mask( p, siglen - hlen - 1, hash_start, hlen, &md_ctx );
1267 buf[0] &= 0xFF >> ( siglen * 8 - msb );
1269 while( p < hash_start - 1 && *p == 0 )
1272 if( p == hash_start ||
1275 mbedtls_md_free( &md_ctx );
1276 return( MBEDTLS_ERR_RSA_INVALID_PADDING );
1279 observed_salt_len = hash_start - p;
1281 if( expected_salt_len != MBEDTLS_RSA_SALT_LEN_ANY &&
1282 observed_salt_len != (size_t) expected_salt_len )
1284 mbedtls_md_free( &md_ctx );
1285 return( MBEDTLS_ERR_RSA_INVALID_PADDING );
1289 * Generate H = Hash( M' )
1291 mbedtls_md_starts( &md_ctx );
1292 mbedtls_md_update( &md_ctx, zeros, 8 );
1293 mbedtls_md_update( &md_ctx, hash, hashlen );
1294 mbedtls_md_update( &md_ctx, p, observed_salt_len );
1295 mbedtls_md_finish( &md_ctx, result );
1297 mbedtls_md_free( &md_ctx );
1299 if( memcmp( hash_start, result, hlen ) == 0 )
1302 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1306 * Simplified PKCS#1 v2.1 RSASSA-PSS-VERIFY function
1308 int mbedtls_rsa_rsassa_pss_verify( mbedtls_rsa_context *ctx,
1309 int (*f_rng)(void *, unsigned char *, size_t),
1312 mbedtls_md_type_t md_alg,
1313 unsigned int hashlen,
1314 const unsigned char *hash,
1315 const unsigned char *sig )
1317 mbedtls_md_type_t mgf1_hash_id = ( ctx->hash_id != MBEDTLS_MD_NONE )
1318 ? (mbedtls_md_type_t) ctx->hash_id
1321 return( mbedtls_rsa_rsassa_pss_verify_ext( ctx, f_rng, p_rng, mode,
1322 md_alg, hashlen, hash,
1323 mgf1_hash_id, MBEDTLS_RSA_SALT_LEN_ANY,
1327 #endif /* MBEDTLS_PKCS1_V21 */
1329 #if defined(MBEDTLS_PKCS1_V15)
1331 * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-v1_5-VERIFY function
1333 int mbedtls_rsa_rsassa_pkcs1_v15_verify( mbedtls_rsa_context *ctx,
1334 int (*f_rng)(void *, unsigned char *, size_t),
1337 mbedtls_md_type_t md_alg,
1338 unsigned int hashlen,
1339 const unsigned char *hash,
1340 const unsigned char *sig )
1343 size_t len, siglen, asn1_len;
1344 unsigned char *p, *end;
1345 mbedtls_md_type_t msg_md_alg;
1346 const mbedtls_md_info_t *md_info;
1347 mbedtls_asn1_buf oid;
1348 unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
1350 if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
1351 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1355 if( siglen < 16 || siglen > sizeof( buf ) )
1356 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1358 ret = ( mode == MBEDTLS_RSA_PUBLIC )
1359 ? mbedtls_rsa_public( ctx, sig, buf )
1360 : mbedtls_rsa_private( ctx, f_rng, p_rng, sig, buf );
1367 if( *p++ != 0 || *p++ != MBEDTLS_RSA_SIGN )
1368 return( MBEDTLS_ERR_RSA_INVALID_PADDING );
1372 if( p >= buf + siglen - 1 || *p != 0xFF )
1373 return( MBEDTLS_ERR_RSA_INVALID_PADDING );
1378 len = siglen - ( p - buf );
1380 if( len == hashlen && md_alg == MBEDTLS_MD_NONE )
1382 if( memcmp( p, hash, hashlen ) == 0 )
1385 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1388 md_info = mbedtls_md_info_from_type( md_alg );
1389 if( md_info == NULL )
1390 return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
1391 hashlen = mbedtls_md_get_size( md_info );
1396 * Parse the ASN.1 structure inside the PKCS#1 v1.5 structure
1398 if( ( ret = mbedtls_asn1_get_tag( &p, end, &asn1_len,
1399 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
1400 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1402 if( asn1_len + 2 != len )
1403 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1405 if( ( ret = mbedtls_asn1_get_tag( &p, end, &asn1_len,
1406 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
1407 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1409 if( asn1_len + 6 + hashlen != len )
1410 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1412 if( ( ret = mbedtls_asn1_get_tag( &p, end, &oid.len, MBEDTLS_ASN1_OID ) ) != 0 )
1413 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1418 if( mbedtls_oid_get_md_alg( &oid, &msg_md_alg ) != 0 )
1419 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1421 if( md_alg != msg_md_alg )
1422 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1425 * assume the algorithm parameters must be NULL
1427 if( ( ret = mbedtls_asn1_get_tag( &p, end, &asn1_len, MBEDTLS_ASN1_NULL ) ) != 0 )
1428 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1430 if( ( ret = mbedtls_asn1_get_tag( &p, end, &asn1_len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
1431 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1433 if( asn1_len != hashlen )
1434 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1436 if( memcmp( p, hash, hashlen ) != 0 )
1437 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1442 return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
1446 #endif /* MBEDTLS_PKCS1_V15 */
1449 * Do an RSA operation and check the message digest
1451 int mbedtls_rsa_pkcs1_verify( mbedtls_rsa_context *ctx,
1452 int (*f_rng)(void *, unsigned char *, size_t),
1455 mbedtls_md_type_t md_alg,
1456 unsigned int hashlen,
1457 const unsigned char *hash,
1458 const unsigned char *sig )
1460 switch( ctx->padding )
1462 #if defined(MBEDTLS_PKCS1_V15)
1463 case MBEDTLS_RSA_PKCS_V15:
1464 return mbedtls_rsa_rsassa_pkcs1_v15_verify( ctx, f_rng, p_rng, mode, md_alg,
1465 hashlen, hash, sig );
1468 #if defined(MBEDTLS_PKCS1_V21)
1469 case MBEDTLS_RSA_PKCS_V21:
1470 return mbedtls_rsa_rsassa_pss_verify( ctx, f_rng, p_rng, mode, md_alg,
1471 hashlen, hash, sig );
1475 return( MBEDTLS_ERR_RSA_INVALID_PADDING );
1480 * Copy the components of an RSA key
1482 int mbedtls_rsa_copy( mbedtls_rsa_context *dst, const mbedtls_rsa_context *src )
1486 dst->ver = src->ver;
1487 dst->len = src->len;
1489 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->N, &src->N ) );
1490 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->E, &src->E ) );
1492 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->D, &src->D ) );
1493 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->P, &src->P ) );
1494 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Q, &src->Q ) );
1495 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->DP, &src->DP ) );
1496 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->DQ, &src->DQ ) );
1497 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->QP, &src->QP ) );
1499 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RN, &src->RN ) );
1500 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RP, &src->RP ) );
1501 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RQ, &src->RQ ) );
1503 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Vi, &src->Vi ) );
1504 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Vf, &src->Vf ) );
1506 dst->padding = src->padding;
1507 dst->hash_id = src->hash_id;
1511 mbedtls_rsa_free( dst );
1517 * Free the components of an RSA key
1519 void mbedtls_rsa_free( mbedtls_rsa_context *ctx )
1521 mbedtls_mpi_free( &ctx->Vi ); mbedtls_mpi_free( &ctx->Vf );
1522 mbedtls_mpi_free( &ctx->RQ ); mbedtls_mpi_free( &ctx->RP ); mbedtls_mpi_free( &ctx->RN );
1523 mbedtls_mpi_free( &ctx->QP ); mbedtls_mpi_free( &ctx->DQ ); mbedtls_mpi_free( &ctx->DP );
1524 mbedtls_mpi_free( &ctx->Q ); mbedtls_mpi_free( &ctx->P ); mbedtls_mpi_free( &ctx->D );
1525 mbedtls_mpi_free( &ctx->E ); mbedtls_mpi_free( &ctx->N );
1527 #if defined(MBEDTLS_THREADING_C)
1528 mbedtls_mutex_free( &ctx->mutex );
1532 #if defined(MBEDTLS_SELF_TEST)
1534 #include "mbedtls/sha1.h"
1537 * Example RSA-1024 keypair, for test purposes
1541 #define RSA_N "9292758453063D803DD603D5E777D788" \
1542 "8ED1D5BF35786190FA2F23EBC0848AEA" \
1543 "DDA92CA6C3D80B32C4D109BE0F36D6AE" \
1544 "7130B9CED7ACDF54CFC7555AC14EEBAB" \
1545 "93A89813FBF3C4F8066D2D800F7C38A8" \
1546 "1AE31942917403FF4946B0A83D3D3E05" \
1547 "EE57C6F5F5606FB5D4BC6CD34EE0801A" \
1548 "5E94BB77B07507233A0BC7BAC8F90F79"
1550 #define RSA_E "10001"
1552 #define RSA_D "24BF6185468786FDD303083D25E64EFC" \
1553 "66CA472BC44D253102F8B4A9D3BFA750" \
1554 "91386C0077937FE33FA3252D28855837" \
1555 "AE1B484A8A9A45F7EE8C0C634F99E8CD" \
1556 "DF79C5CE07EE72C7F123142198164234" \
1557 "CABB724CF78B8173B9F880FC86322407" \
1558 "AF1FEDFDDE2BEB674CA15F3E81A1521E" \
1559 "071513A1E85B5DFA031F21ECAE91A34D"
1561 #define RSA_P "C36D0EB7FCD285223CFB5AABA5BDA3D8" \
1562 "2C01CAD19EA484A87EA4377637E75500" \
1563 "FCB2005C5C7DD6EC4AC023CDA285D796" \
1564 "C3D9E75E1EFC42488BB4F1D13AC30A57"
1566 #define RSA_Q "C000DF51A7C77AE8D7C7370C1FF55B69" \
1567 "E211C2B9E5DB1ED0BF61D0D9899620F4" \
1568 "910E4168387E3C30AA1E00C339A79508" \
1569 "8452DD96A9A5EA5D9DCA68DA636032AF"
1571 #define RSA_DP "C1ACF567564274FB07A0BBAD5D26E298" \
1572 "3C94D22288ACD763FD8E5600ED4A702D" \
1573 "F84198A5F06C2E72236AE490C93F07F8" \
1574 "3CC559CD27BC2D1CA488811730BB5725"
1576 #define RSA_DQ "4959CBF6F8FEF750AEE6977C155579C7" \
1577 "D8AAEA56749EA28623272E4F7D0592AF" \
1578 "7C1F1313CAC9471B5C523BFE592F517B" \
1579 "407A1BD76C164B93DA2D32A383E58357"
1581 #define RSA_QP "9AE7FBC99546432DF71896FC239EADAE" \
1582 "F38D18D2B2F0E2DD275AA977E2BF4411" \
1583 "F5A3B2A5D33605AEBBCCBA7FEB9F2D2F" \
1584 "A74206CEC169D74BF5A8C50D6F48EA08"
1587 #define RSA_PT "\xAA\xBB\xCC\x03\x02\x01\x00\xFF\xFF\xFF\xFF\xFF" \
1588 "\x11\x22\x33\x0A\x0B\x0C\xCC\xDD\xDD\xDD\xDD\xDD"
1590 #if defined(MBEDTLS_PKCS1_V15)
1591 static int myrand( void *rng_state, unsigned char *output, size_t len )
1593 #if !defined(__OpenBSD__)
1596 if( rng_state != NULL )
1599 for( i = 0; i < len; ++i )
1602 if( rng_state != NULL )
1605 arc4random_buf( output, len );
1606 #endif /* !OpenBSD */
1610 #endif /* MBEDTLS_PKCS1_V15 */
1615 int mbedtls_rsa_self_test( int verbose )
1618 #if defined(MBEDTLS_PKCS1_V15)
1620 mbedtls_rsa_context rsa;
1621 unsigned char rsa_plaintext[PT_LEN];
1622 unsigned char rsa_decrypted[PT_LEN];
1623 unsigned char rsa_ciphertext[KEY_LEN];
1624 #if defined(MBEDTLS_SHA1_C)
1625 unsigned char sha1sum[20];
1628 mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 );
1631 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.N , 16, RSA_N ) );
1632 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.E , 16, RSA_E ) );
1633 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.D , 16, RSA_D ) );
1634 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.P , 16, RSA_P ) );
1635 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.Q , 16, RSA_Q ) );
1636 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.DP, 16, RSA_DP ) );
1637 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.DQ, 16, RSA_DQ ) );
1638 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.QP, 16, RSA_QP ) );
1641 mbedtls_printf( " RSA key validation: " );
1643 if( mbedtls_rsa_check_pubkey( &rsa ) != 0 ||
1644 mbedtls_rsa_check_privkey( &rsa ) != 0 )
1647 mbedtls_printf( "failed\n" );
1653 mbedtls_printf( "passed\n PKCS#1 encryption : " );
1655 memcpy( rsa_plaintext, RSA_PT, PT_LEN );
1657 if( mbedtls_rsa_pkcs1_encrypt( &rsa, myrand, NULL, MBEDTLS_RSA_PUBLIC, PT_LEN,
1658 rsa_plaintext, rsa_ciphertext ) != 0 )
1661 mbedtls_printf( "failed\n" );
1667 mbedtls_printf( "passed\n PKCS#1 decryption : " );
1669 if( mbedtls_rsa_pkcs1_decrypt( &rsa, myrand, NULL, MBEDTLS_RSA_PRIVATE, &len,
1670 rsa_ciphertext, rsa_decrypted,
1671 sizeof(rsa_decrypted) ) != 0 )
1674 mbedtls_printf( "failed\n" );
1679 if( memcmp( rsa_decrypted, rsa_plaintext, len ) != 0 )
1682 mbedtls_printf( "failed\n" );
1688 mbedtls_printf( "passed\n" );
1690 #if defined(MBEDTLS_SHA1_C)
1692 mbedtls_printf( " PKCS#1 data sign : " );
1694 mbedtls_sha1( rsa_plaintext, PT_LEN, sha1sum );
1696 if( mbedtls_rsa_pkcs1_sign( &rsa, myrand, NULL, MBEDTLS_RSA_PRIVATE, MBEDTLS_MD_SHA1, 0,
1697 sha1sum, rsa_ciphertext ) != 0 )
1700 mbedtls_printf( "failed\n" );
1706 mbedtls_printf( "passed\n PKCS#1 sig. verify: " );
1708 if( mbedtls_rsa_pkcs1_verify( &rsa, NULL, NULL, MBEDTLS_RSA_PUBLIC, MBEDTLS_MD_SHA1, 0,
1709 sha1sum, rsa_ciphertext ) != 0 )
1712 mbedtls_printf( "failed\n" );
1718 mbedtls_printf( "passed\n" );
1719 #endif /* MBEDTLS_SHA1_C */
1722 mbedtls_printf( "\n" );
1725 mbedtls_rsa_free( &rsa );
1726 #else /* MBEDTLS_PKCS1_V15 */
1728 #endif /* MBEDTLS_PKCS1_V15 */
1732 #endif /* MBEDTLS_SELF_TEST */
1734 #endif /* MBEDTLS_RSA_C */