Doug Anson
mbed TLS library
Dependents: HTTPClient-SSL WS_SERVER
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rsa.c
00001 /* 00002 * The RSA public-key cryptosystem 00003 * 00004 * Copyright (C) 2006-2014, ARM Limited, All Rights Reserved 00005 * 00006 * This file is part of mbed TLS (https://tls.mbed.org) 00007 * 00008 * This program is free software; you can redistribute it and/or modify 00009 * it under the terms of the GNU General Public License as published by 00010 * the Free Software Foundation; either version 2 of the License, or 00011 * (at your option) any later version. 00012 * 00013 * This program is distributed in the hope that it will be useful, 00014 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00016 * GNU General Public License for more details. 00017 * 00018 * You should have received a copy of the GNU General Public License along 00019 * with this program; if not, write to the Free Software Foundation, Inc., 00020 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 00021 */ 00022 /* 00023 * RSA was designed by Ron Rivest, Adi Shamir and Len Adleman. 00024 * 00025 * http://theory.lcs.mit.edu/~rivest/rsapaper.pdf 00026 * http://www.cacr.math.uwaterloo.ca/hac/about/chap8.pdf 00027 */ 00028 00029 #if !defined(POLARSSL_CONFIG_FILE) 00030 #include "polarssl/config.h" 00031 #else 00032 #include POLARSSL_CONFIG_FILE 00033 #endif 00034 00035 #if defined(POLARSSL_RSA_C) 00036 00037 #include "polarssl/rsa.h" 00038 #include "polarssl/oid.h" 00039 00040 #include <string.h> 00041 00042 #if defined(POLARSSL_PKCS1_V21) 00043 #include "polarssl/md.h" 00044 #endif 00045 00046 #if defined(POLARSSL_PKCS1_V15) && !defined(__OpenBSD__) 00047 #include <stdlib.h> 00048 #endif 00049 00050 #if defined(POLARSSL_PLATFORM_C) 00051 #include "polarssl/platform.h" 00052 #else 00053 #include <stdio.h> 00054 #define polarssl_printf printf 00055 #endif 00056 00057 /* 00058 * Initialize an RSA context 00059 */ 00060 void rsa_init( rsa_context *ctx, 00061 int padding, 00062 int hash_id ) 00063 { 00064 memset( ctx, 0, sizeof( rsa_context ) ); 00065 00066 rsa_set_padding( ctx, padding, hash_id ); 00067 00068 #if defined(POLARSSL_THREADING_C) 00069 polarssl_mutex_init( &ctx->mutex ); 00070 #endif 00071 } 00072 00073 /* 00074 * Set padding for an existing RSA context 00075 */ 00076 void rsa_set_padding( rsa_context *ctx, int padding, int hash_id ) 00077 { 00078 ctx->padding = padding; 00079 ctx->hash_id = hash_id; 00080 } 00081 00082 #if defined(POLARSSL_GENPRIME) 00083 00084 /* 00085 * Generate an RSA keypair 00086 */ 00087 int rsa_gen_key( rsa_context *ctx, 00088 int (*f_rng)(void *, unsigned char *, size_t), 00089 void *p_rng, 00090 unsigned int nbits, int exponent ) 00091 { 00092 int ret; 00093 mpi P1, Q1, H, G; 00094 00095 if( f_rng == NULL || nbits < 128 || exponent < 3 ) 00096 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00097 00098 mpi_init( &P1 ); mpi_init( &Q1 ); mpi_init( &H ); mpi_init( &G ); 00099 00100 /* 00101 * find primes P and Q with Q < P so that: 00102 * GCD( E, (P-1)*(Q-1) ) == 1 00103 */ 00104 MPI_CHK( mpi_lset( &ctx->E , exponent ) ); 00105 00106 do 00107 { 00108 MPI_CHK( mpi_gen_prime( &ctx->P , ( nbits + 1 ) >> 1, 0, 00109 f_rng, p_rng ) ); 00110 00111 MPI_CHK( mpi_gen_prime( &ctx->Q , ( nbits + 1 ) >> 1, 0, 00112 f_rng, p_rng ) ); 00113 00114 if( mpi_cmp_mpi( &ctx->P , &ctx->Q ) < 0 ) 00115 mpi_swap( &ctx->P , &ctx->Q ); 00116 00117 if( mpi_cmp_mpi( &ctx->P , &ctx->Q ) == 0 ) 00118 continue; 00119 00120 MPI_CHK( mpi_mul_mpi( &ctx->N , &ctx->P , &ctx->Q ) ); 00121 if( mpi_msb( &ctx->N ) != nbits ) 00122 continue; 00123 00124 MPI_CHK( mpi_sub_int( &P1, &ctx->P , 1 ) ); 00125 MPI_CHK( mpi_sub_int( &Q1, &ctx->Q , 1 ) ); 00126 MPI_CHK( mpi_mul_mpi( &H, &P1, &Q1 ) ); 00127 MPI_CHK( mpi_gcd( &G, &ctx->E , &H ) ); 00128 } 00129 while( mpi_cmp_int( &G, 1 ) != 0 ); 00130 00131 /* 00132 * D = E^-1 mod ((P-1)*(Q-1)) 00133 * DP = D mod (P - 1) 00134 * DQ = D mod (Q - 1) 00135 * QP = Q^-1 mod P 00136 */ 00137 MPI_CHK( mpi_inv_mod( &ctx->D , &ctx->E , &H ) ); 00138 MPI_CHK( mpi_mod_mpi( &ctx->DP , &ctx->D , &P1 ) ); 00139 MPI_CHK( mpi_mod_mpi( &ctx->DQ , &ctx->D , &Q1 ) ); 00140 MPI_CHK( mpi_inv_mod( &ctx->QP , &ctx->Q , &ctx->P ) ); 00141 00142 ctx->len = ( mpi_msb( &ctx->N ) + 7 ) >> 3; 00143 00144 cleanup: 00145 00146 mpi_free( &P1 ); mpi_free( &Q1 ); mpi_free( &H ); mpi_free( &G ); 00147 00148 if( ret != 0 ) 00149 { 00150 rsa_free( ctx ); 00151 return( POLARSSL_ERR_RSA_KEY_GEN_FAILED + ret ); 00152 } 00153 00154 return( 0 ); 00155 } 00156 00157 #endif /* POLARSSL_GENPRIME */ 00158 00159 /* 00160 * Check a public RSA key 00161 */ 00162 int rsa_check_pubkey( const rsa_context *ctx ) 00163 { 00164 if( !ctx->N .p || !ctx->E .p ) 00165 return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED ); 00166 00167 if( ( ctx->N .p [0] & 1 ) == 0 || 00168 ( ctx->E .p [0] & 1 ) == 0 ) 00169 return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED ); 00170 00171 if( mpi_msb( &ctx->N ) < 128 || 00172 mpi_msb( &ctx->N ) > POLARSSL_MPI_MAX_BITS ) 00173 return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED ); 00174 00175 if( mpi_msb( &ctx->E ) < 2 || 00176 mpi_cmp_mpi( &ctx->E , &ctx->N ) >= 0 ) 00177 return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED ); 00178 00179 return( 0 ); 00180 } 00181 00182 /* 00183 * Check a private RSA key 00184 */ 00185 int rsa_check_privkey( const rsa_context *ctx ) 00186 { 00187 int ret; 00188 mpi PQ, DE, P1, Q1, H, I, G, G2, L1, L2, DP, DQ, QP; 00189 00190 if( ( ret = rsa_check_pubkey( ctx ) ) != 0 ) 00191 return( ret ); 00192 00193 if( !ctx->P .p || !ctx->Q .p || !ctx->D .p ) 00194 return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED ); 00195 00196 mpi_init( &PQ ); mpi_init( &DE ); mpi_init( &P1 ); mpi_init( &Q1 ); 00197 mpi_init( &H ); mpi_init( &I ); mpi_init( &G ); mpi_init( &G2 ); 00198 mpi_init( &L1 ); mpi_init( &L2 ); mpi_init( &DP ); mpi_init( &DQ ); 00199 mpi_init( &QP ); 00200 00201 MPI_CHK( mpi_mul_mpi( &PQ, &ctx->P , &ctx->Q ) ); 00202 MPI_CHK( mpi_mul_mpi( &DE, &ctx->D , &ctx->E ) ); 00203 MPI_CHK( mpi_sub_int( &P1, &ctx->P , 1 ) ); 00204 MPI_CHK( mpi_sub_int( &Q1, &ctx->Q , 1 ) ); 00205 MPI_CHK( mpi_mul_mpi( &H, &P1, &Q1 ) ); 00206 MPI_CHK( mpi_gcd( &G, &ctx->E , &H ) ); 00207 00208 MPI_CHK( mpi_gcd( &G2, &P1, &Q1 ) ); 00209 MPI_CHK( mpi_div_mpi( &L1, &L2, &H, &G2 ) ); 00210 MPI_CHK( mpi_mod_mpi( &I, &DE, &L1 ) ); 00211 00212 MPI_CHK( mpi_mod_mpi( &DP, &ctx->D , &P1 ) ); 00213 MPI_CHK( mpi_mod_mpi( &DQ, &ctx->D , &Q1 ) ); 00214 MPI_CHK( mpi_inv_mod( &QP, &ctx->Q , &ctx->P ) ); 00215 /* 00216 * Check for a valid PKCS1v2 private key 00217 */ 00218 if( mpi_cmp_mpi( &PQ, &ctx->N ) != 0 || 00219 mpi_cmp_mpi( &DP, &ctx->DP ) != 0 || 00220 mpi_cmp_mpi( &DQ, &ctx->DQ ) != 0 || 00221 mpi_cmp_mpi( &QP, &ctx->QP ) != 0 || 00222 mpi_cmp_int( &L2, 0 ) != 0 || 00223 mpi_cmp_int( &I, 1 ) != 0 || 00224 mpi_cmp_int( &G, 1 ) != 0 ) 00225 { 00226 ret = POLARSSL_ERR_RSA_KEY_CHECK_FAILED; 00227 } 00228 00229 cleanup: 00230 mpi_free( &PQ ); mpi_free( &DE ); mpi_free( &P1 ); mpi_free( &Q1 ); 00231 mpi_free( &H ); mpi_free( &I ); mpi_free( &G ); mpi_free( &G2 ); 00232 mpi_free( &L1 ); mpi_free( &L2 ); mpi_free( &DP ); mpi_free( &DQ ); 00233 mpi_free( &QP ); 00234 00235 if( ret == POLARSSL_ERR_RSA_KEY_CHECK_FAILED ) 00236 return( ret ); 00237 00238 if( ret != 0 ) 00239 return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED + ret ); 00240 00241 return( 0 ); 00242 } 00243 00244 /* 00245 * Check if contexts holding a public and private key match 00246 */ 00247 int rsa_check_pub_priv( const rsa_context *pub, const rsa_context *prv ) 00248 { 00249 if( rsa_check_pubkey( pub ) != 0 || 00250 rsa_check_privkey( prv ) != 0 ) 00251 { 00252 return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED ); 00253 } 00254 00255 if( mpi_cmp_mpi( &pub->N , &prv->N ) != 0 || 00256 mpi_cmp_mpi( &pub->E , &prv->E ) != 0 ) 00257 { 00258 return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED ); 00259 } 00260 00261 return( 0 ); 00262 } 00263 00264 /* 00265 * Do an RSA public key operation 00266 */ 00267 int rsa_public( rsa_context *ctx, 00268 const unsigned char *input, 00269 unsigned char *output ) 00270 { 00271 int ret; 00272 size_t olen; 00273 mpi T; 00274 00275 mpi_init( &T ); 00276 00277 MPI_CHK( mpi_read_binary( &T, input, ctx->len ) ); 00278 00279 if( mpi_cmp_mpi( &T, &ctx->N ) >= 0 ) 00280 { 00281 mpi_free( &T ); 00282 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00283 } 00284 00285 #if defined(POLARSSL_THREADING_C) 00286 polarssl_mutex_lock( &ctx->mutex ); 00287 #endif 00288 00289 olen = ctx->len ; 00290 MPI_CHK( mpi_exp_mod( &T, &T, &ctx->E , &ctx->N , &ctx->RN ) ); 00291 MPI_CHK( mpi_write_binary( &T, output, olen ) ); 00292 00293 cleanup: 00294 #if defined(POLARSSL_THREADING_C) 00295 polarssl_mutex_unlock( &ctx->mutex ); 00296 #endif 00297 00298 mpi_free( &T ); 00299 00300 if( ret != 0 ) 00301 return( POLARSSL_ERR_RSA_PUBLIC_FAILED + ret ); 00302 00303 return( 0 ); 00304 } 00305 00306 /* 00307 * Generate or update blinding values, see section 10 of: 00308 * KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA, 00309 * DSS, and other systems. In : Advances in Cryptology—CRYPTO’96. Springer 00310 * Berlin Heidelberg, 1996. p. 104-113. 00311 */ 00312 static int rsa_prepare_blinding( rsa_context *ctx, mpi *Vi, mpi *Vf, 00313 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ) 00314 { 00315 int ret, count = 0; 00316 00317 #if defined(POLARSSL_THREADING_C) 00318 polarssl_mutex_lock( &ctx->mutex ); 00319 #endif 00320 00321 if( ctx->Vf .p != NULL ) 00322 { 00323 /* We already have blinding values, just update them by squaring */ 00324 MPI_CHK( mpi_mul_mpi( &ctx->Vi , &ctx->Vi , &ctx->Vi ) ); 00325 MPI_CHK( mpi_mod_mpi( &ctx->Vi , &ctx->Vi , &ctx->N ) ); 00326 MPI_CHK( mpi_mul_mpi( &ctx->Vf , &ctx->Vf , &ctx->Vf ) ); 00327 MPI_CHK( mpi_mod_mpi( &ctx->Vf , &ctx->Vf , &ctx->N ) ); 00328 00329 goto done; 00330 } 00331 00332 /* Unblinding value: Vf = random number, invertible mod N */ 00333 do { 00334 if( count++ > 10 ) 00335 return( POLARSSL_ERR_RSA_RNG_FAILED ); 00336 00337 MPI_CHK( mpi_fill_random( &ctx->Vf , ctx->len - 1, f_rng, p_rng ) ); 00338 MPI_CHK( mpi_gcd( &ctx->Vi , &ctx->Vf , &ctx->N ) ); 00339 } while( mpi_cmp_int( &ctx->Vi , 1 ) != 0 ); 00340 00341 /* Blinding value: Vi = Vf^(-e) mod N */ 00342 MPI_CHK( mpi_inv_mod( &ctx->Vi , &ctx->Vf , &ctx->N ) ); 00343 MPI_CHK( mpi_exp_mod( &ctx->Vi , &ctx->Vi , &ctx->E , &ctx->N , &ctx->RN ) ); 00344 00345 done: 00346 if( Vi != &ctx->Vi ) 00347 { 00348 MPI_CHK( mpi_copy( Vi, &ctx->Vi ) ); 00349 MPI_CHK( mpi_copy( Vf, &ctx->Vf ) ); 00350 } 00351 00352 cleanup: 00353 #if defined(POLARSSL_THREADING_C) 00354 polarssl_mutex_unlock( &ctx->mutex ); 00355 #endif 00356 00357 return( ret ); 00358 } 00359 00360 /* 00361 * Do an RSA private key operation 00362 */ 00363 int rsa_private( rsa_context *ctx, 00364 int (*f_rng)(void *, unsigned char *, size_t), 00365 void *p_rng, 00366 const unsigned char *input, 00367 unsigned char *output ) 00368 { 00369 int ret; 00370 size_t olen; 00371 mpi T, T1, T2; 00372 mpi *Vi, *Vf; 00373 00374 /* 00375 * When using the Chinese Remainder Theorem, we use blinding values. 00376 * Without threading, we just read them directly from the context, 00377 * otherwise we make a local copy in order to reduce locking contention. 00378 */ 00379 #if defined(POLARSSL_THREADING_C) 00380 mpi Vi_copy, Vf_copy; 00381 00382 mpi_init( &Vi_copy ); mpi_init( &Vf_copy ); 00383 Vi = &Vi_copy; 00384 Vf = &Vf_copy; 00385 #else 00386 Vi = &ctx->Vi ; 00387 Vf = &ctx->Vf ; 00388 #endif 00389 00390 mpi_init( &T ); mpi_init( &T1 ); mpi_init( &T2 ); 00391 00392 MPI_CHK( mpi_read_binary( &T, input, ctx->len ) ); 00393 if( mpi_cmp_mpi( &T, &ctx->N ) >= 0 ) 00394 { 00395 mpi_free( &T ); 00396 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00397 } 00398 00399 if( f_rng != NULL ) 00400 { 00401 /* 00402 * Blinding 00403 * T = T * Vi mod N 00404 */ 00405 MPI_CHK( rsa_prepare_blinding( ctx, Vi, Vf, f_rng, p_rng ) ); 00406 MPI_CHK( mpi_mul_mpi( &T, &T, Vi ) ); 00407 MPI_CHK( mpi_mod_mpi( &T, &T, &ctx->N ) ); 00408 } 00409 00410 #if defined(POLARSSL_THREADING_C) 00411 polarssl_mutex_lock( &ctx->mutex ); 00412 #endif 00413 00414 #if defined(POLARSSL_RSA_NO_CRT) 00415 MPI_CHK( mpi_exp_mod( &T, &T, &ctx->D , &ctx->N , &ctx->RN ) ); 00416 #else 00417 /* 00418 * faster decryption using the CRT 00419 * 00420 * T1 = input ^ dP mod P 00421 * T2 = input ^ dQ mod Q 00422 */ 00423 MPI_CHK( mpi_exp_mod( &T1, &T, &ctx->DP , &ctx->P , &ctx->RP ) ); 00424 MPI_CHK( mpi_exp_mod( &T2, &T, &ctx->DQ , &ctx->Q , &ctx->RQ ) ); 00425 00426 /* 00427 * T = (T1 - T2) * (Q^-1 mod P) mod P 00428 */ 00429 MPI_CHK( mpi_sub_mpi( &T, &T1, &T2 ) ); 00430 MPI_CHK( mpi_mul_mpi( &T1, &T, &ctx->QP ) ); 00431 MPI_CHK( mpi_mod_mpi( &T, &T1, &ctx->P ) ); 00432 00433 /* 00434 * T = T2 + T * Q 00435 */ 00436 MPI_CHK( mpi_mul_mpi( &T1, &T, &ctx->Q ) ); 00437 MPI_CHK( mpi_add_mpi( &T, &T2, &T1 ) ); 00438 #endif /* POLARSSL_RSA_NO_CRT */ 00439 00440 if( f_rng != NULL ) 00441 { 00442 /* 00443 * Unblind 00444 * T = T * Vf mod N 00445 */ 00446 MPI_CHK( mpi_mul_mpi( &T, &T, Vf ) ); 00447 MPI_CHK( mpi_mod_mpi( &T, &T, &ctx->N ) ); 00448 } 00449 00450 olen = ctx->len ; 00451 MPI_CHK( mpi_write_binary( &T, output, olen ) ); 00452 00453 cleanup: 00454 #if defined(POLARSSL_THREADING_C) 00455 polarssl_mutex_unlock( &ctx->mutex ); 00456 mpi_free( &Vi_copy ); mpi_free( &Vf_copy ); 00457 #endif 00458 mpi_free( &T ); mpi_free( &T1 ); mpi_free( &T2 ); 00459 00460 if( ret != 0 ) 00461 return( POLARSSL_ERR_RSA_PRIVATE_FAILED + ret ); 00462 00463 return( 0 ); 00464 } 00465 00466 #if defined(POLARSSL_PKCS1_V21) 00467 /** 00468 * Generate and apply the MGF1 operation (from PKCS#1 v2.1) to a buffer. 00469 * 00470 * \param dst buffer to mask 00471 * \param dlen length of destination buffer 00472 * \param src source of the mask generation 00473 * \param slen length of the source buffer 00474 * \param md_ctx message digest context to use 00475 */ 00476 static void mgf_mask( unsigned char *dst, size_t dlen, unsigned char *src, 00477 size_t slen, md_context_t *md_ctx ) 00478 { 00479 unsigned char mask[POLARSSL_MD_MAX_SIZE]; 00480 unsigned char counter[4]; 00481 unsigned char *p; 00482 unsigned int hlen; 00483 size_t i, use_len; 00484 00485 memset( mask, 0, POLARSSL_MD_MAX_SIZE ); 00486 memset( counter, 0, 4 ); 00487 00488 hlen = md_ctx->md_info->size; 00489 00490 // Generate and apply dbMask 00491 // 00492 p = dst; 00493 00494 while( dlen > 0 ) 00495 { 00496 use_len = hlen; 00497 if( dlen < hlen ) 00498 use_len = dlen; 00499 00500 md_starts( md_ctx ); 00501 md_update( md_ctx, src, slen ); 00502 md_update( md_ctx, counter, 4 ); 00503 md_finish( md_ctx, mask ); 00504 00505 for( i = 0; i < use_len; ++i ) 00506 *p++ ^= mask[i]; 00507 00508 counter[3]++; 00509 00510 dlen -= use_len; 00511 } 00512 } 00513 #endif /* POLARSSL_PKCS1_V21 */ 00514 00515 #if defined(POLARSSL_PKCS1_V21) 00516 /* 00517 * Implementation of the PKCS#1 v2.1 RSAES-OAEP-ENCRYPT function 00518 */ 00519 int rsa_rsaes_oaep_encrypt( rsa_context *ctx, 00520 int (*f_rng)(void *, unsigned char *, size_t), 00521 void *p_rng, 00522 int mode, 00523 const unsigned char *label, size_t label_len, 00524 size_t ilen, 00525 const unsigned char *input, 00526 unsigned char *output ) 00527 { 00528 size_t olen; 00529 int ret; 00530 unsigned char *p = output; 00531 unsigned int hlen; 00532 const md_info_t *md_info; 00533 md_context_t md_ctx; 00534 00535 if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V21 ) 00536 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00537 00538 if( f_rng == NULL ) 00539 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00540 00541 md_info = md_info_from_type( (md_type_t) ctx->hash_id ); 00542 if( md_info == NULL ) 00543 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00544 00545 olen = ctx->len ; 00546 hlen = md_get_size( md_info ); 00547 00548 if( olen < ilen + 2 * hlen + 2 ) 00549 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00550 00551 memset( output, 0, olen ); 00552 00553 *p++ = 0; 00554 00555 // Generate a random octet string seed 00556 // 00557 if( ( ret = f_rng( p_rng, p, hlen ) ) != 0 ) 00558 return( POLARSSL_ERR_RSA_RNG_FAILED + ret ); 00559 00560 p += hlen; 00561 00562 // Construct DB 00563 // 00564 md( md_info, label, label_len, p ); 00565 p += hlen; 00566 p += olen - 2 * hlen - 2 - ilen; 00567 *p++ = 1; 00568 memcpy( p, input, ilen ); 00569 00570 md_init( &md_ctx ); 00571 md_init_ctx( &md_ctx, md_info ); 00572 00573 // maskedDB: Apply dbMask to DB 00574 // 00575 mgf_mask( output + hlen + 1, olen - hlen - 1, output + 1, hlen, 00576 &md_ctx ); 00577 00578 // maskedSeed: Apply seedMask to seed 00579 // 00580 mgf_mask( output + 1, hlen, output + hlen + 1, olen - hlen - 1, 00581 &md_ctx ); 00582 00583 md_free( &md_ctx ); 00584 00585 return( ( mode == RSA_PUBLIC ) 00586 ? rsa_public( ctx, output, output ) 00587 : rsa_private( ctx, f_rng, p_rng, output, output ) ); 00588 } 00589 #endif /* POLARSSL_PKCS1_V21 */ 00590 00591 #if defined(POLARSSL_PKCS1_V15) 00592 /* 00593 * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-ENCRYPT function 00594 */ 00595 int rsa_rsaes_pkcs1_v15_encrypt( rsa_context *ctx, 00596 int (*f_rng)(void *, unsigned char *, size_t), 00597 void *p_rng, 00598 int mode, size_t ilen, 00599 const unsigned char *input, 00600 unsigned char *output ) 00601 { 00602 size_t nb_pad, olen; 00603 int ret; 00604 unsigned char *p = output; 00605 00606 if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V15 ) 00607 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00608 00609 if( f_rng == NULL ) 00610 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00611 00612 olen = ctx->len ; 00613 00614 if( olen < ilen + 11 ) 00615 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00616 00617 nb_pad = olen - 3 - ilen; 00618 00619 *p++ = 0; 00620 if( mode == RSA_PUBLIC ) 00621 { 00622 *p++ = RSA_CRYPT; 00623 00624 while( nb_pad-- > 0 ) 00625 { 00626 int rng_dl = 100; 00627 00628 do { 00629 ret = f_rng( p_rng, p, 1 ); 00630 } while( *p == 0 && --rng_dl && ret == 0 ); 00631 00632 // Check if RNG failed to generate data 00633 // 00634 if( rng_dl == 0 || ret != 0 ) 00635 return( POLARSSL_ERR_RSA_RNG_FAILED + ret ); 00636 00637 p++; 00638 } 00639 } 00640 else 00641 { 00642 *p++ = RSA_SIGN; 00643 00644 while( nb_pad-- > 0 ) 00645 *p++ = 0xFF; 00646 } 00647 00648 *p++ = 0; 00649 memcpy( p, input, ilen ); 00650 00651 return( ( mode == RSA_PUBLIC ) 00652 ? rsa_public( ctx, output, output ) 00653 : rsa_private( ctx, f_rng, p_rng, output, output ) ); 00654 } 00655 #endif /* POLARSSL_PKCS1_V15 */ 00656 00657 /* 00658 * Add the message padding, then do an RSA operation 00659 */ 00660 int rsa_pkcs1_encrypt( rsa_context *ctx, 00661 int (*f_rng)(void *, unsigned char *, size_t), 00662 void *p_rng, 00663 int mode, size_t ilen, 00664 const unsigned char *input, 00665 unsigned char *output ) 00666 { 00667 switch( ctx->padding ) 00668 { 00669 #if defined(POLARSSL_PKCS1_V15) 00670 case RSA_PKCS_V15: 00671 return rsa_rsaes_pkcs1_v15_encrypt( ctx, f_rng, p_rng, mode, ilen, 00672 input, output ); 00673 #endif 00674 00675 #if defined(POLARSSL_PKCS1_V21) 00676 case RSA_PKCS_V21: 00677 return rsa_rsaes_oaep_encrypt( ctx, f_rng, p_rng, mode, NULL, 0, 00678 ilen, input, output ); 00679 #endif 00680 00681 default: 00682 return( POLARSSL_ERR_RSA_INVALID_PADDING ); 00683 } 00684 } 00685 00686 #if defined(POLARSSL_PKCS1_V21) 00687 /* 00688 * Implementation of the PKCS#1 v2.1 RSAES-OAEP-DECRYPT function 00689 */ 00690 int rsa_rsaes_oaep_decrypt( rsa_context *ctx, 00691 int (*f_rng)(void *, unsigned char *, size_t), 00692 void *p_rng, 00693 int mode, 00694 const unsigned char *label, size_t label_len, 00695 size_t *olen, 00696 const unsigned char *input, 00697 unsigned char *output, 00698 size_t output_max_len ) 00699 { 00700 int ret; 00701 size_t ilen, i, pad_len; 00702 unsigned char *p, bad, pad_done; 00703 unsigned char buf[POLARSSL_MPI_MAX_SIZE]; 00704 unsigned char lhash[POLARSSL_MD_MAX_SIZE]; 00705 unsigned int hlen; 00706 const md_info_t *md_info; 00707 md_context_t md_ctx; 00708 00709 /* 00710 * Parameters sanity checks 00711 */ 00712 if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V21 ) 00713 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00714 00715 ilen = ctx->len ; 00716 00717 if( ilen < 16 || ilen > sizeof( buf ) ) 00718 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00719 00720 md_info = md_info_from_type( (md_type_t) ctx->hash_id ); 00721 if( md_info == NULL ) 00722 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00723 00724 /* 00725 * RSA operation 00726 */ 00727 ret = ( mode == RSA_PUBLIC ) 00728 ? rsa_public( ctx, input, buf ) 00729 : rsa_private( ctx, f_rng, p_rng, input, buf ); 00730 00731 if( ret != 0 ) 00732 return( ret ); 00733 00734 /* 00735 * Unmask data and generate lHash 00736 */ 00737 hlen = md_get_size( md_info ); 00738 00739 md_init( &md_ctx ); 00740 md_init_ctx( &md_ctx, md_info ); 00741 00742 /* Generate lHash */ 00743 md( md_info, label, label_len, lhash ); 00744 00745 /* seed: Apply seedMask to maskedSeed */ 00746 mgf_mask( buf + 1, hlen, buf + hlen + 1, ilen - hlen - 1, 00747 &md_ctx ); 00748 00749 /* DB: Apply dbMask to maskedDB */ 00750 mgf_mask( buf + hlen + 1, ilen - hlen - 1, buf + 1, hlen, 00751 &md_ctx ); 00752 00753 md_free( &md_ctx ); 00754 00755 /* 00756 * Check contents, in "constant-time" 00757 */ 00758 p = buf; 00759 bad = 0; 00760 00761 bad |= *p++; /* First byte must be 0 */ 00762 00763 p += hlen; /* Skip seed */ 00764 00765 /* Check lHash */ 00766 for( i = 0; i < hlen; i++ ) 00767 bad |= lhash[i] ^ *p++; 00768 00769 /* Get zero-padding len, but always read till end of buffer 00770 * (minus one, for the 01 byte) */ 00771 pad_len = 0; 00772 pad_done = 0; 00773 for( i = 0; i < ilen - 2 * hlen - 2; i++ ) 00774 { 00775 pad_done |= p[i]; 00776 pad_len += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1; 00777 } 00778 00779 p += pad_len; 00780 bad |= *p++ ^ 0x01; 00781 00782 /* 00783 * The only information "leaked" is whether the padding was correct or not 00784 * (eg, no data is copied if it was not correct). This meets the 00785 * recommendations in PKCS#1 v2.2: an opponent cannot distinguish between 00786 * the different error conditions. 00787 */ 00788 if( bad != 0 ) 00789 return( POLARSSL_ERR_RSA_INVALID_PADDING ); 00790 00791 if( ilen - ( p - buf ) > output_max_len ) 00792 return( POLARSSL_ERR_RSA_OUTPUT_TOO_LARGE ); 00793 00794 *olen = ilen - (p - buf); 00795 memcpy( output, p, *olen ); 00796 00797 return( 0 ); 00798 } 00799 #endif /* POLARSSL_PKCS1_V21 */ 00800 00801 #if defined(POLARSSL_PKCS1_V15) 00802 /* 00803 * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-DECRYPT function 00804 */ 00805 int rsa_rsaes_pkcs1_v15_decrypt( rsa_context *ctx, 00806 int (*f_rng)(void *, unsigned char *, size_t), 00807 void *p_rng, 00808 int mode, size_t *olen, 00809 const unsigned char *input, 00810 unsigned char *output, 00811 size_t output_max_len) 00812 { 00813 int ret; 00814 size_t ilen, pad_count = 0, i; 00815 unsigned char *p, bad, pad_done = 0; 00816 unsigned char buf[POLARSSL_MPI_MAX_SIZE]; 00817 00818 if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V15 ) 00819 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00820 00821 ilen = ctx->len ; 00822 00823 if( ilen < 16 || ilen > sizeof( buf ) ) 00824 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00825 00826 ret = ( mode == RSA_PUBLIC ) 00827 ? rsa_public( ctx, input, buf ) 00828 : rsa_private( ctx, f_rng, p_rng, input, buf ); 00829 00830 if( ret != 0 ) 00831 return( ret ); 00832 00833 p = buf; 00834 bad = 0; 00835 00836 /* 00837 * Check and get padding len in "constant-time" 00838 */ 00839 bad |= *p++; /* First byte must be 0 */ 00840 00841 /* This test does not depend on secret data */ 00842 if( mode == RSA_PRIVATE ) 00843 { 00844 bad |= *p++ ^ RSA_CRYPT; 00845 00846 /* Get padding len, but always read till end of buffer 00847 * (minus one, for the 00 byte) */ 00848 for( i = 0; i < ilen - 3; i++ ) 00849 { 00850 pad_done |= ((p[i] | (unsigned char)-p[i]) >> 7) ^ 1; 00851 pad_count += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1; 00852 } 00853 00854 p += pad_count; 00855 bad |= *p++; /* Must be zero */ 00856 } 00857 else 00858 { 00859 bad |= *p++ ^ RSA_SIGN; 00860 00861 /* Get padding len, but always read till end of buffer 00862 * (minus one, for the 00 byte) */ 00863 for( i = 0; i < ilen - 3; i++ ) 00864 { 00865 pad_done |= ( p[i] != 0xFF ); 00866 pad_count += ( pad_done == 0 ); 00867 } 00868 00869 p += pad_count; 00870 bad |= *p++; /* Must be zero */ 00871 } 00872 00873 if( bad ) 00874 return( POLARSSL_ERR_RSA_INVALID_PADDING ); 00875 00876 if( ilen - ( p - buf ) > output_max_len ) 00877 return( POLARSSL_ERR_RSA_OUTPUT_TOO_LARGE ); 00878 00879 *olen = ilen - (p - buf); 00880 memcpy( output, p, *olen ); 00881 00882 return( 0 ); 00883 } 00884 #endif /* POLARSSL_PKCS1_V15 */ 00885 00886 /* 00887 * Do an RSA operation, then remove the message padding 00888 */ 00889 int rsa_pkcs1_decrypt( rsa_context *ctx, 00890 int (*f_rng)(void *, unsigned char *, size_t), 00891 void *p_rng, 00892 int mode, size_t *olen, 00893 const unsigned char *input, 00894 unsigned char *output, 00895 size_t output_max_len) 00896 { 00897 switch( ctx->padding ) 00898 { 00899 #if defined(POLARSSL_PKCS1_V15) 00900 case RSA_PKCS_V15: 00901 return rsa_rsaes_pkcs1_v15_decrypt( ctx, f_rng, p_rng, mode, olen, 00902 input, output, output_max_len ); 00903 #endif 00904 00905 #if defined(POLARSSL_PKCS1_V21) 00906 case RSA_PKCS_V21: 00907 return rsa_rsaes_oaep_decrypt( ctx, f_rng, p_rng, mode, NULL, 0, 00908 olen, input, output, 00909 output_max_len ); 00910 #endif 00911 00912 default: 00913 return( POLARSSL_ERR_RSA_INVALID_PADDING ); 00914 } 00915 } 00916 00917 #if defined(POLARSSL_PKCS1_V21) 00918 /* 00919 * Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function 00920 */ 00921 int rsa_rsassa_pss_sign( rsa_context *ctx, 00922 int (*f_rng)(void *, unsigned char *, size_t), 00923 void *p_rng, 00924 int mode, 00925 md_type_t md_alg, 00926 unsigned int hashlen, 00927 const unsigned char *hash, 00928 unsigned char *sig ) 00929 { 00930 size_t olen; 00931 unsigned char *p = sig; 00932 unsigned char salt[POLARSSL_MD_MAX_SIZE]; 00933 unsigned int slen, hlen, offset = 0; 00934 int ret; 00935 size_t msb; 00936 const md_info_t *md_info; 00937 md_context_t md_ctx; 00938 00939 if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V21 ) 00940 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00941 00942 if( f_rng == NULL ) 00943 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00944 00945 olen = ctx->len ; 00946 00947 if( md_alg != POLARSSL_MD_NONE ) 00948 { 00949 // Gather length of hash to sign 00950 // 00951 md_info = md_info_from_type( md_alg ); 00952 if( md_info == NULL ) 00953 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00954 00955 hashlen = md_get_size( md_info ); 00956 } 00957 00958 md_info = md_info_from_type( (md_type_t) ctx->hash_id ); 00959 if( md_info == NULL ) 00960 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00961 00962 hlen = md_get_size( md_info ); 00963 slen = hlen; 00964 00965 if( olen < hlen + slen + 2 ) 00966 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 00967 00968 memset( sig, 0, olen ); 00969 00970 // Generate salt of length slen 00971 // 00972 if( ( ret = f_rng( p_rng, salt, slen ) ) != 0 ) 00973 return( POLARSSL_ERR_RSA_RNG_FAILED + ret ); 00974 00975 // Note: EMSA-PSS encoding is over the length of N - 1 bits 00976 // 00977 msb = mpi_msb( &ctx->N ) - 1; 00978 p += olen - hlen * 2 - 2; 00979 *p++ = 0x01; 00980 memcpy( p, salt, slen ); 00981 p += slen; 00982 00983 md_init( &md_ctx ); 00984 md_init_ctx( &md_ctx, md_info ); 00985 00986 // Generate H = Hash( M' ) 00987 // 00988 md_starts( &md_ctx ); 00989 md_update( &md_ctx, p, 8 ); 00990 md_update( &md_ctx, hash, hashlen ); 00991 md_update( &md_ctx, salt, slen ); 00992 md_finish( &md_ctx, p ); 00993 00994 // Compensate for boundary condition when applying mask 00995 // 00996 if( msb % 8 == 0 ) 00997 offset = 1; 00998 00999 // maskedDB: Apply dbMask to DB 01000 // 01001 mgf_mask( sig + offset, olen - hlen - 1 - offset, p, hlen, &md_ctx ); 01002 01003 md_free( &md_ctx ); 01004 01005 msb = mpi_msb( &ctx->N ) - 1; 01006 sig[0] &= 0xFF >> ( olen * 8 - msb ); 01007 01008 p += hlen; 01009 *p++ = 0xBC; 01010 01011 return( ( mode == RSA_PUBLIC ) 01012 ? rsa_public( ctx, sig, sig ) 01013 : rsa_private( ctx, f_rng, p_rng, sig, sig ) ); 01014 } 01015 #endif /* POLARSSL_PKCS1_V21 */ 01016 01017 #if defined(POLARSSL_PKCS1_V15) 01018 /* 01019 * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-V1_5-SIGN function 01020 */ 01021 /* 01022 * Do an RSA operation to sign the message digest 01023 */ 01024 int rsa_rsassa_pkcs1_v15_sign( rsa_context *ctx, 01025 int (*f_rng)(void *, unsigned char *, size_t), 01026 void *p_rng, 01027 int mode, 01028 md_type_t md_alg, 01029 unsigned int hashlen, 01030 const unsigned char *hash, 01031 unsigned char *sig ) 01032 { 01033 size_t nb_pad, olen, oid_size = 0; 01034 unsigned char *p = sig; 01035 const char *oid = NULL; 01036 01037 if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V15 ) 01038 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01039 01040 olen = ctx->len ; 01041 nb_pad = olen - 3; 01042 01043 if( md_alg != POLARSSL_MD_NONE ) 01044 { 01045 const md_info_t *md_info = md_info_from_type( md_alg ); 01046 if( md_info == NULL ) 01047 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01048 01049 if( oid_get_oid_by_md( md_alg, &oid, &oid_size ) != 0 ) 01050 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01051 01052 nb_pad -= 10 + oid_size; 01053 01054 hashlen = md_get_size( md_info ); 01055 } 01056 01057 nb_pad -= hashlen; 01058 01059 if( ( nb_pad < 8 ) || ( nb_pad > olen ) ) 01060 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01061 01062 *p++ = 0; 01063 *p++ = RSA_SIGN; 01064 memset( p, 0xFF, nb_pad ); 01065 p += nb_pad; 01066 *p++ = 0; 01067 01068 if( md_alg == POLARSSL_MD_NONE ) 01069 { 01070 memcpy( p, hash, hashlen ); 01071 } 01072 else 01073 { 01074 /* 01075 * DigestInfo ::= SEQUENCE { 01076 * digestAlgorithm DigestAlgorithmIdentifier, 01077 * digest Digest } 01078 * 01079 * DigestAlgorithmIdentifier ::= AlgorithmIdentifier 01080 * 01081 * Digest ::= OCTET STRING 01082 */ 01083 *p++ = ASN1_SEQUENCE | ASN1_CONSTRUCTED; 01084 *p++ = (unsigned char) ( 0x08 + oid_size + hashlen ); 01085 *p++ = ASN1_SEQUENCE | ASN1_CONSTRUCTED; 01086 *p++ = (unsigned char) ( 0x04 + oid_size ); 01087 *p++ = ASN1_OID; 01088 *p++ = oid_size & 0xFF; 01089 memcpy( p, oid, oid_size ); 01090 p += oid_size; 01091 *p++ = ASN1_NULL; 01092 *p++ = 0x00; 01093 *p++ = ASN1_OCTET_STRING; 01094 *p++ = hashlen; 01095 memcpy( p, hash, hashlen ); 01096 } 01097 01098 return( ( mode == RSA_PUBLIC ) 01099 ? rsa_public( ctx, sig, sig ) 01100 : rsa_private( ctx, f_rng, p_rng, sig, sig ) ); 01101 } 01102 #endif /* POLARSSL_PKCS1_V15 */ 01103 01104 /* 01105 * Do an RSA operation to sign the message digest 01106 */ 01107 int rsa_pkcs1_sign( rsa_context *ctx, 01108 int (*f_rng)(void *, unsigned char *, size_t), 01109 void *p_rng, 01110 int mode, 01111 md_type_t md_alg, 01112 unsigned int hashlen, 01113 const unsigned char *hash, 01114 unsigned char *sig ) 01115 { 01116 switch( ctx->padding ) 01117 { 01118 #if defined(POLARSSL_PKCS1_V15) 01119 case RSA_PKCS_V15: 01120 return rsa_rsassa_pkcs1_v15_sign( ctx, f_rng, p_rng, mode, md_alg, 01121 hashlen, hash, sig ); 01122 #endif 01123 01124 #if defined(POLARSSL_PKCS1_V21) 01125 case RSA_PKCS_V21: 01126 return rsa_rsassa_pss_sign( ctx, f_rng, p_rng, mode, md_alg, 01127 hashlen, hash, sig ); 01128 #endif 01129 01130 default: 01131 return( POLARSSL_ERR_RSA_INVALID_PADDING ); 01132 } 01133 } 01134 01135 #if defined(POLARSSL_PKCS1_V21) 01136 /* 01137 * Implementation of the PKCS#1 v2.1 RSASSA-PSS-VERIFY function 01138 */ 01139 int rsa_rsassa_pss_verify_ext( rsa_context *ctx, 01140 int (*f_rng)(void *, unsigned char *, size_t), 01141 void *p_rng, 01142 int mode, 01143 md_type_t md_alg, 01144 unsigned int hashlen, 01145 const unsigned char *hash, 01146 md_type_t mgf1_hash_id, 01147 int expected_salt_len, 01148 const unsigned char *sig ) 01149 { 01150 int ret; 01151 size_t siglen; 01152 unsigned char *p; 01153 unsigned char buf[POLARSSL_MPI_MAX_SIZE]; 01154 unsigned char result[POLARSSL_MD_MAX_SIZE]; 01155 unsigned char zeros[8]; 01156 unsigned int hlen; 01157 size_t slen, msb; 01158 const md_info_t *md_info; 01159 md_context_t md_ctx; 01160 01161 if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V21 ) 01162 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01163 01164 siglen = ctx->len ; 01165 01166 if( siglen < 16 || siglen > sizeof( buf ) ) 01167 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01168 01169 ret = ( mode == RSA_PUBLIC ) 01170 ? rsa_public( ctx, sig, buf ) 01171 : rsa_private( ctx, f_rng, p_rng, sig, buf ); 01172 01173 if( ret != 0 ) 01174 return( ret ); 01175 01176 p = buf; 01177 01178 if( buf[siglen - 1] != 0xBC ) 01179 return( POLARSSL_ERR_RSA_INVALID_PADDING ); 01180 01181 if( md_alg != POLARSSL_MD_NONE ) 01182 { 01183 // Gather length of hash to sign 01184 // 01185 md_info = md_info_from_type( md_alg ); 01186 if( md_info == NULL ) 01187 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01188 01189 hashlen = md_get_size( md_info ); 01190 } 01191 01192 md_info = md_info_from_type( mgf1_hash_id ); 01193 if( md_info == NULL ) 01194 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01195 01196 hlen = md_get_size( md_info ); 01197 slen = siglen - hlen - 1; /* Currently length of salt + padding */ 01198 01199 memset( zeros, 0, 8 ); 01200 01201 // Note: EMSA-PSS verification is over the length of N - 1 bits 01202 // 01203 msb = mpi_msb( &ctx->N ) - 1; 01204 01205 // Compensate for boundary condition when applying mask 01206 // 01207 if( msb % 8 == 0 ) 01208 { 01209 p++; 01210 siglen -= 1; 01211 } 01212 if( buf[0] >> ( 8 - siglen * 8 + msb ) ) 01213 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01214 01215 md_init( &md_ctx ); 01216 md_init_ctx( &md_ctx, md_info ); 01217 01218 mgf_mask( p, siglen - hlen - 1, p + siglen - hlen - 1, hlen, &md_ctx ); 01219 01220 buf[0] &= 0xFF >> ( siglen * 8 - msb ); 01221 01222 while( p < buf + siglen && *p == 0 ) 01223 p++; 01224 01225 if( p == buf + siglen || 01226 *p++ != 0x01 ) 01227 { 01228 md_free( &md_ctx ); 01229 return( POLARSSL_ERR_RSA_INVALID_PADDING ); 01230 } 01231 01232 /* Actual salt len */ 01233 slen -= p - buf; 01234 01235 if( expected_salt_len != RSA_SALT_LEN_ANY && 01236 slen != (size_t) expected_salt_len ) 01237 { 01238 md_free( &md_ctx ); 01239 return( POLARSSL_ERR_RSA_INVALID_PADDING ); 01240 } 01241 01242 // Generate H = Hash( M' ) 01243 // 01244 md_starts( &md_ctx ); 01245 md_update( &md_ctx, zeros, 8 ); 01246 md_update( &md_ctx, hash, hashlen ); 01247 md_update( &md_ctx, p, slen ); 01248 md_finish( &md_ctx, result ); 01249 01250 md_free( &md_ctx ); 01251 01252 if( memcmp( p + slen, result, hlen ) == 0 ) 01253 return( 0 ); 01254 else 01255 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01256 } 01257 01258 /* 01259 * Simplified PKCS#1 v2.1 RSASSA-PSS-VERIFY function 01260 */ 01261 int rsa_rsassa_pss_verify( rsa_context *ctx, 01262 int (*f_rng)(void *, unsigned char *, size_t), 01263 void *p_rng, 01264 int mode, 01265 md_type_t md_alg, 01266 unsigned int hashlen, 01267 const unsigned char *hash, 01268 const unsigned char *sig ) 01269 { 01270 md_type_t mgf1_hash_id = ( ctx->hash_id != POLARSSL_MD_NONE ) 01271 ? (md_type_t) ctx->hash_id 01272 : md_alg; 01273 01274 return( rsa_rsassa_pss_verify_ext( ctx, f_rng, p_rng, mode, 01275 md_alg, hashlen, hash, 01276 mgf1_hash_id, RSA_SALT_LEN_ANY, 01277 sig ) ); 01278 01279 } 01280 #endif /* POLARSSL_PKCS1_V21 */ 01281 01282 #if defined(POLARSSL_PKCS1_V15) 01283 /* 01284 * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-v1_5-VERIFY function 01285 */ 01286 int rsa_rsassa_pkcs1_v15_verify( rsa_context *ctx, 01287 int (*f_rng)(void *, unsigned char *, size_t), 01288 void *p_rng, 01289 int mode, 01290 md_type_t md_alg, 01291 unsigned int hashlen, 01292 const unsigned char *hash, 01293 const unsigned char *sig ) 01294 { 01295 int ret; 01296 size_t len, siglen, asn1_len; 01297 unsigned char *p, *end; 01298 unsigned char buf[POLARSSL_MPI_MAX_SIZE]; 01299 md_type_t msg_md_alg; 01300 const md_info_t *md_info; 01301 asn1_buf oid; 01302 01303 if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V15 ) 01304 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01305 01306 siglen = ctx->len ; 01307 01308 if( siglen < 16 || siglen > sizeof( buf ) ) 01309 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01310 01311 ret = ( mode == RSA_PUBLIC ) 01312 ? rsa_public( ctx, sig, buf ) 01313 : rsa_private( ctx, f_rng, p_rng, sig, buf ); 01314 01315 if( ret != 0 ) 01316 return( ret ); 01317 01318 p = buf; 01319 01320 if( *p++ != 0 || *p++ != RSA_SIGN ) 01321 return( POLARSSL_ERR_RSA_INVALID_PADDING ); 01322 01323 while( *p != 0 ) 01324 { 01325 if( p >= buf + siglen - 1 || *p != 0xFF ) 01326 return( POLARSSL_ERR_RSA_INVALID_PADDING ); 01327 p++; 01328 } 01329 p++; 01330 01331 len = siglen - ( p - buf ); 01332 01333 if( len == hashlen && md_alg == POLARSSL_MD_NONE ) 01334 { 01335 if( memcmp( p, hash, hashlen ) == 0 ) 01336 return( 0 ); 01337 else 01338 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01339 } 01340 01341 md_info = md_info_from_type( md_alg ); 01342 if( md_info == NULL ) 01343 return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); 01344 hashlen = md_get_size( md_info ); 01345 01346 end = p + len; 01347 01348 // Parse the ASN.1 structure inside the PKCS#1 v1.5 structure 01349 // 01350 if( ( ret = asn1_get_tag( &p, end, &asn1_len, 01351 ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) 01352 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01353 01354 if( asn1_len + 2 != len ) 01355 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01356 01357 if( ( ret = asn1_get_tag( &p, end, &asn1_len, 01358 ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) 01359 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01360 01361 if( asn1_len + 6 + hashlen != len ) 01362 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01363 01364 if( ( ret = asn1_get_tag( &p, end, &oid.len, ASN1_OID ) ) != 0 ) 01365 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01366 01367 oid.p = p; 01368 p += oid.len; 01369 01370 if( oid_get_md_alg( &oid, &msg_md_alg ) != 0 ) 01371 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01372 01373 if( md_alg != msg_md_alg ) 01374 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01375 01376 /* 01377 * assume the algorithm parameters must be NULL 01378 */ 01379 if( ( ret = asn1_get_tag( &p, end, &asn1_len, ASN1_NULL ) ) != 0 ) 01380 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01381 01382 if( ( ret = asn1_get_tag( &p, end, &asn1_len, ASN1_OCTET_STRING ) ) != 0 ) 01383 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01384 01385 if( asn1_len != hashlen ) 01386 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01387 01388 if( memcmp( p, hash, hashlen ) != 0 ) 01389 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01390 01391 p += hashlen; 01392 01393 if( p != end ) 01394 return( POLARSSL_ERR_RSA_VERIFY_FAILED ); 01395 01396 return( 0 ); 01397 } 01398 #endif /* POLARSSL_PKCS1_V15 */ 01399 01400 /* 01401 * Do an RSA operation and check the message digest 01402 */ 01403 int rsa_pkcs1_verify( rsa_context *ctx, 01404 int (*f_rng)(void *, unsigned char *, size_t), 01405 void *p_rng, 01406 int mode, 01407 md_type_t md_alg, 01408 unsigned int hashlen, 01409 const unsigned char *hash, 01410 const unsigned char *sig ) 01411 { 01412 switch( ctx->padding ) 01413 { 01414 #if defined(POLARSSL_PKCS1_V15) 01415 case RSA_PKCS_V15: 01416 return rsa_rsassa_pkcs1_v15_verify( ctx, f_rng, p_rng, mode, md_alg, 01417 hashlen, hash, sig ); 01418 #endif 01419 01420 #if defined(POLARSSL_PKCS1_V21) 01421 case RSA_PKCS_V21: 01422 return rsa_rsassa_pss_verify( ctx, f_rng, p_rng, mode, md_alg, 01423 hashlen, hash, sig ); 01424 #endif 01425 01426 default: 01427 return( POLARSSL_ERR_RSA_INVALID_PADDING ); 01428 } 01429 } 01430 01431 /* 01432 * Copy the components of an RSA key 01433 */ 01434 int rsa_copy( rsa_context *dst, const rsa_context *src ) 01435 { 01436 int ret; 01437 01438 dst->ver = src->ver ; 01439 dst->len = src->len ; 01440 01441 MPI_CHK( mpi_copy( &dst->N , &src->N ) ); 01442 MPI_CHK( mpi_copy( &dst->E , &src->E ) ); 01443 01444 MPI_CHK( mpi_copy( &dst->D , &src->D ) ); 01445 MPI_CHK( mpi_copy( &dst->P , &src->P ) ); 01446 MPI_CHK( mpi_copy( &dst->Q , &src->Q ) ); 01447 MPI_CHK( mpi_copy( &dst->DP , &src->DP ) ); 01448 MPI_CHK( mpi_copy( &dst->DQ , &src->DQ ) ); 01449 MPI_CHK( mpi_copy( &dst->QP , &src->QP ) ); 01450 01451 MPI_CHK( mpi_copy( &dst->RN , &src->RN ) ); 01452 MPI_CHK( mpi_copy( &dst->RP , &src->RP ) ); 01453 MPI_CHK( mpi_copy( &dst->RQ , &src->RQ ) ); 01454 01455 MPI_CHK( mpi_copy( &dst->Vi , &src->Vi ) ); 01456 MPI_CHK( mpi_copy( &dst->Vf , &src->Vf ) ); 01457 01458 dst->padding = src->padding ; 01459 dst->hash_id = src->hash_id ; 01460 01461 cleanup: 01462 if( ret != 0 ) 01463 rsa_free( dst ); 01464 01465 return( ret ); 01466 } 01467 01468 /* 01469 * Free the components of an RSA key 01470 */ 01471 void rsa_free( rsa_context *ctx ) 01472 { 01473 mpi_free( &ctx->Vi ); mpi_free( &ctx->Vf ); 01474 mpi_free( &ctx->RQ ); mpi_free( &ctx->RP ); mpi_free( &ctx->RN ); 01475 mpi_free( &ctx->QP ); mpi_free( &ctx->DQ ); mpi_free( &ctx->DP ); 01476 mpi_free( &ctx->Q ); mpi_free( &ctx->P ); mpi_free( &ctx->D ); 01477 mpi_free( &ctx->E ); mpi_free( &ctx->N ); 01478 01479 #if defined(POLARSSL_THREADING_C) 01480 polarssl_mutex_free( &ctx->mutex ); 01481 #endif 01482 } 01483 01484 #if defined(POLARSSL_SELF_TEST) 01485 01486 #include "polarssl/sha1.h" 01487 01488 /* 01489 * Example RSA-1024 keypair, for test purposes 01490 */ 01491 #define KEY_LEN 128 01492 01493 #define RSA_N "9292758453063D803DD603D5E777D788" \ 01494 "8ED1D5BF35786190FA2F23EBC0848AEA" \ 01495 "DDA92CA6C3D80B32C4D109BE0F36D6AE" \ 01496 "7130B9CED7ACDF54CFC7555AC14EEBAB" \ 01497 "93A89813FBF3C4F8066D2D800F7C38A8" \ 01498 "1AE31942917403FF4946B0A83D3D3E05" \ 01499 "EE57C6F5F5606FB5D4BC6CD34EE0801A" \ 01500 "5E94BB77B07507233A0BC7BAC8F90F79" 01501 01502 #define RSA_E "10001" 01503 01504 #define RSA_D "24BF6185468786FDD303083D25E64EFC" \ 01505 "66CA472BC44D253102F8B4A9D3BFA750" \ 01506 "91386C0077937FE33FA3252D28855837" \ 01507 "AE1B484A8A9A45F7EE8C0C634F99E8CD" \ 01508 "DF79C5CE07EE72C7F123142198164234" \ 01509 "CABB724CF78B8173B9F880FC86322407" \ 01510 "AF1FEDFDDE2BEB674CA15F3E81A1521E" \ 01511 "071513A1E85B5DFA031F21ECAE91A34D" 01512 01513 #define RSA_P "C36D0EB7FCD285223CFB5AABA5BDA3D8" \ 01514 "2C01CAD19EA484A87EA4377637E75500" \ 01515 "FCB2005C5C7DD6EC4AC023CDA285D796" \ 01516 "C3D9E75E1EFC42488BB4F1D13AC30A57" 01517 01518 #define RSA_Q "C000DF51A7C77AE8D7C7370C1FF55B69" \ 01519 "E211C2B9E5DB1ED0BF61D0D9899620F4" \ 01520 "910E4168387E3C30AA1E00C339A79508" \ 01521 "8452DD96A9A5EA5D9DCA68DA636032AF" 01522 01523 #define RSA_DP "C1ACF567564274FB07A0BBAD5D26E298" \ 01524 "3C94D22288ACD763FD8E5600ED4A702D" \ 01525 "F84198A5F06C2E72236AE490C93F07F8" \ 01526 "3CC559CD27BC2D1CA488811730BB5725" 01527 01528 #define RSA_DQ "4959CBF6F8FEF750AEE6977C155579C7" \ 01529 "D8AAEA56749EA28623272E4F7D0592AF" \ 01530 "7C1F1313CAC9471B5C523BFE592F517B" \ 01531 "407A1BD76C164B93DA2D32A383E58357" 01532 01533 #define RSA_QP "9AE7FBC99546432DF71896FC239EADAE" \ 01534 "F38D18D2B2F0E2DD275AA977E2BF4411" \ 01535 "F5A3B2A5D33605AEBBCCBA7FEB9F2D2F" \ 01536 "A74206CEC169D74BF5A8C50D6F48EA08" 01537 01538 #define PT_LEN 24 01539 #define RSA_PT "\xAA\xBB\xCC\x03\x02\x01\x00\xFF\xFF\xFF\xFF\xFF" \ 01540 "\x11\x22\x33\x0A\x0B\x0C\xCC\xDD\xDD\xDD\xDD\xDD" 01541 01542 #if defined(POLARSSL_PKCS1_V15) 01543 static int myrand( void *rng_state, unsigned char *output, size_t len ) 01544 { 01545 #if !defined(__OpenBSD__) 01546 size_t i; 01547 01548 if( rng_state != NULL ) 01549 rng_state = NULL; 01550 01551 for( i = 0; i < len; ++i ) 01552 output[i] = rand(); 01553 #else 01554 if( rng_state != NULL ) 01555 rng_state = NULL; 01556 01557 arc4random_buf( output, len ); 01558 #endif /* !OpenBSD */ 01559 01560 return( 0 ); 01561 } 01562 #endif /* POLARSSL_PKCS1_V15 */ 01563 01564 /* 01565 * Checkup routine 01566 */ 01567 int rsa_self_test( int verbose ) 01568 { 01569 int ret = 0; 01570 #if defined(POLARSSL_PKCS1_V15) 01571 size_t len; 01572 rsa_context rsa; 01573 unsigned char rsa_plaintext[PT_LEN]; 01574 unsigned char rsa_decrypted[PT_LEN]; 01575 unsigned char rsa_ciphertext[KEY_LEN]; 01576 #if defined(POLARSSL_SHA1_C) 01577 unsigned char sha1sum[20]; 01578 #endif 01579 01580 rsa_init( &rsa, RSA_PKCS_V15, 0 ); 01581 01582 rsa.len = KEY_LEN; 01583 MPI_CHK( mpi_read_string( &rsa.N , 16, RSA_N ) ); 01584 MPI_CHK( mpi_read_string( &rsa.E , 16, RSA_E ) ); 01585 MPI_CHK( mpi_read_string( &rsa.D , 16, RSA_D ) ); 01586 MPI_CHK( mpi_read_string( &rsa.P , 16, RSA_P ) ); 01587 MPI_CHK( mpi_read_string( &rsa.Q , 16, RSA_Q ) ); 01588 MPI_CHK( mpi_read_string( &rsa.DP , 16, RSA_DP ) ); 01589 MPI_CHK( mpi_read_string( &rsa.DQ , 16, RSA_DQ ) ); 01590 MPI_CHK( mpi_read_string( &rsa.QP , 16, RSA_QP ) ); 01591 01592 if( verbose != 0 ) 01593 polarssl_printf( " RSA key validation: " ); 01594 01595 if( rsa_check_pubkey( &rsa ) != 0 || 01596 rsa_check_privkey( &rsa ) != 0 ) 01597 { 01598 if( verbose != 0 ) 01599 polarssl_printf( "failed\n" ); 01600 01601 return( 1 ); 01602 } 01603 01604 if( verbose != 0 ) 01605 polarssl_printf( "passed\n PKCS#1 encryption : " ); 01606 01607 memcpy( rsa_plaintext, RSA_PT, PT_LEN ); 01608 01609 if( rsa_pkcs1_encrypt( &rsa, myrand, NULL, RSA_PUBLIC, PT_LEN, 01610 rsa_plaintext, rsa_ciphertext ) != 0 ) 01611 { 01612 if( verbose != 0 ) 01613 polarssl_printf( "failed\n" ); 01614 01615 return( 1 ); 01616 } 01617 01618 if( verbose != 0 ) 01619 polarssl_printf( "passed\n PKCS#1 decryption : " ); 01620 01621 if( rsa_pkcs1_decrypt( &rsa, myrand, NULL, RSA_PRIVATE, &len, 01622 rsa_ciphertext, rsa_decrypted, 01623 sizeof(rsa_decrypted) ) != 0 ) 01624 { 01625 if( verbose != 0 ) 01626 polarssl_printf( "failed\n" ); 01627 01628 return( 1 ); 01629 } 01630 01631 if( memcmp( rsa_decrypted, rsa_plaintext, len ) != 0 ) 01632 { 01633 if( verbose != 0 ) 01634 polarssl_printf( "failed\n" ); 01635 01636 return( 1 ); 01637 } 01638 01639 #if defined(POLARSSL_SHA1_C) 01640 if( verbose != 0 ) 01641 polarssl_printf( "passed\n PKCS#1 data sign : " ); 01642 01643 sha1( rsa_plaintext, PT_LEN, sha1sum ); 01644 01645 if( rsa_pkcs1_sign( &rsa, myrand, NULL, RSA_PRIVATE, POLARSSL_MD_SHA1, 0, 01646 sha1sum, rsa_ciphertext ) != 0 ) 01647 { 01648 if( verbose != 0 ) 01649 polarssl_printf( "failed\n" ); 01650 01651 return( 1 ); 01652 } 01653 01654 if( verbose != 0 ) 01655 polarssl_printf( "passed\n PKCS#1 sig. verify: " ); 01656 01657 if( rsa_pkcs1_verify( &rsa, NULL, NULL, RSA_PUBLIC, POLARSSL_MD_SHA1, 0, 01658 sha1sum, rsa_ciphertext ) != 0 ) 01659 { 01660 if( verbose != 0 ) 01661 polarssl_printf( "failed\n" ); 01662 01663 return( 1 ); 01664 } 01665 01666 if( verbose != 0 ) 01667 polarssl_printf( "passed\n\n" ); 01668 #endif /* POLARSSL_SHA1_C */ 01669 01670 cleanup: 01671 rsa_free( &rsa ); 01672 #else /* POLARSSL_PKCS1_V15 */ 01673 ((void) verbose); 01674 #endif /* POLARSSL_PKCS1_V15 */ 01675 return( ret ); 01676 } 01677 01678 #endif /* POLARSSL_SELF_TEST */ 01679 01680 #endif /* POLARSSL_RSA_C */ 01681
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