rsa_pss.c revision 296341
1/* rsa_pss.c */ 2/* 3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project 4 * 2005. 5 */ 6/* ==================================================================== 7 * Copyright (c) 2005 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * licensing@OpenSSL.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 57 * 58 */ 59 60#include <stdio.h> 61#include "cryptlib.h" 62#include <openssl/bn.h> 63#include <openssl/rsa.h> 64#include <openssl/evp.h> 65#include <openssl/rand.h> 66#include <openssl/sha.h> 67 68static const unsigned char zeroes[] = { 0, 0, 0, 0, 0, 0, 0, 0 }; 69 70#if defined(_MSC_VER) && defined(_ARM_) 71# pragma optimize("g", off) 72#endif 73 74int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash, 75 const EVP_MD *Hash, const unsigned char *EM, 76 int sLen) 77{ 78 return RSA_verify_PKCS1_PSS_mgf1(rsa, mHash, Hash, NULL, EM, sLen); 79} 80 81int RSA_verify_PKCS1_PSS_mgf1(RSA *rsa, const unsigned char *mHash, 82 const EVP_MD *Hash, const EVP_MD *mgf1Hash, 83 const unsigned char *EM, int sLen) 84{ 85 int i; 86 int ret = 0; 87 int hLen, maskedDBLen, MSBits, emLen; 88 const unsigned char *H; 89 unsigned char *DB = NULL; 90 EVP_MD_CTX ctx; 91 unsigned char H_[EVP_MAX_MD_SIZE]; 92 EVP_MD_CTX_init(&ctx); 93 94 if (mgf1Hash == NULL) 95 mgf1Hash = Hash; 96 97 hLen = EVP_MD_size(Hash); 98 if (hLen < 0) 99 goto err; 100 /*- 101 * Negative sLen has special meanings: 102 * -1 sLen == hLen 103 * -2 salt length is autorecovered from signature 104 * -N reserved 105 */ 106 if (sLen == -1) 107 sLen = hLen; 108 else if (sLen == -2) 109 sLen = -2; 110 else if (sLen < -2) { 111 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED); 112 goto err; 113 } 114 115 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7; 116 emLen = RSA_size(rsa); 117 if (EM[0] & (0xFF << MSBits)) { 118 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_FIRST_OCTET_INVALID); 119 goto err; 120 } 121 if (MSBits == 0) { 122 EM++; 123 emLen--; 124 } 125 if (emLen < (hLen + sLen + 2)) { /* sLen can be small negative */ 126 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_DATA_TOO_LARGE); 127 goto err; 128 } 129 if (EM[emLen - 1] != 0xbc) { 130 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_LAST_OCTET_INVALID); 131 goto err; 132 } 133 maskedDBLen = emLen - hLen - 1; 134 H = EM + maskedDBLen; 135 DB = OPENSSL_malloc(maskedDBLen); 136 if (!DB) { 137 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, ERR_R_MALLOC_FAILURE); 138 goto err; 139 } 140 if (PKCS1_MGF1(DB, maskedDBLen, H, hLen, mgf1Hash) < 0) 141 goto err; 142 for (i = 0; i < maskedDBLen; i++) 143 DB[i] ^= EM[i]; 144 if (MSBits) 145 DB[0] &= 0xFF >> (8 - MSBits); 146 for (i = 0; DB[i] == 0 && i < (maskedDBLen - 1); i++) ; 147 if (DB[i++] != 0x1) { 148 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_RECOVERY_FAILED); 149 goto err; 150 } 151 if (sLen >= 0 && (maskedDBLen - i) != sLen) { 152 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED); 153 goto err; 154 } 155 if (!EVP_DigestInit_ex(&ctx, Hash, NULL) 156 || !EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes) 157 || !EVP_DigestUpdate(&ctx, mHash, hLen)) 158 goto err; 159 if (maskedDBLen - i) { 160 if (!EVP_DigestUpdate(&ctx, DB + i, maskedDBLen - i)) 161 goto err; 162 } 163 if (!EVP_DigestFinal_ex(&ctx, H_, NULL)) 164 goto err; 165 if (memcmp(H_, H, hLen)) { 166 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_BAD_SIGNATURE); 167 ret = 0; 168 } else 169 ret = 1; 170 171 err: 172 if (DB) 173 OPENSSL_free(DB); 174 EVP_MD_CTX_cleanup(&ctx); 175 176 return ret; 177 178} 179 180int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM, 181 const unsigned char *mHash, 182 const EVP_MD *Hash, int sLen) 183{ 184 return RSA_padding_add_PKCS1_PSS_mgf1(rsa, EM, mHash, Hash, NULL, sLen); 185} 186 187int RSA_padding_add_PKCS1_PSS_mgf1(RSA *rsa, unsigned char *EM, 188 const unsigned char *mHash, 189 const EVP_MD *Hash, const EVP_MD *mgf1Hash, 190 int sLen) 191{ 192 int i; 193 int ret = 0; 194 int hLen, maskedDBLen, MSBits, emLen; 195 unsigned char *H, *salt = NULL, *p; 196 EVP_MD_CTX ctx; 197 198 if (mgf1Hash == NULL) 199 mgf1Hash = Hash; 200 201 hLen = EVP_MD_size(Hash); 202 if (hLen < 0) 203 goto err; 204 /*- 205 * Negative sLen has special meanings: 206 * -1 sLen == hLen 207 * -2 salt length is maximized 208 * -N reserved 209 */ 210 if (sLen == -1) 211 sLen = hLen; 212 else if (sLen == -2) 213 sLen = -2; 214 else if (sLen < -2) { 215 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED); 216 goto err; 217 } 218 219 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7; 220 emLen = RSA_size(rsa); 221 if (MSBits == 0) { 222 *EM++ = 0; 223 emLen--; 224 } 225 if (sLen == -2) { 226 sLen = emLen - hLen - 2; 227 } else if (emLen < (hLen + sLen + 2)) { 228 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1, 229 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); 230 goto err; 231 } 232 if (sLen > 0) { 233 salt = OPENSSL_malloc(sLen); 234 if (!salt) { 235 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1, 236 ERR_R_MALLOC_FAILURE); 237 goto err; 238 } 239 if (RAND_bytes(salt, sLen) <= 0) 240 goto err; 241 } 242 maskedDBLen = emLen - hLen - 1; 243 H = EM + maskedDBLen; 244 EVP_MD_CTX_init(&ctx); 245 if (!EVP_DigestInit_ex(&ctx, Hash, NULL) 246 || !EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes) 247 || !EVP_DigestUpdate(&ctx, mHash, hLen)) 248 goto err; 249 if (sLen && !EVP_DigestUpdate(&ctx, salt, sLen)) 250 goto err; 251 if (!EVP_DigestFinal_ex(&ctx, H, NULL)) 252 goto err; 253 EVP_MD_CTX_cleanup(&ctx); 254 255 /* Generate dbMask in place then perform XOR on it */ 256 if (PKCS1_MGF1(EM, maskedDBLen, H, hLen, mgf1Hash)) 257 goto err; 258 259 p = EM; 260 261 /* 262 * Initial PS XORs with all zeroes which is a NOP so just update pointer. 263 * Note from a test above this value is guaranteed to be non-negative. 264 */ 265 p += emLen - sLen - hLen - 2; 266 *p++ ^= 0x1; 267 if (sLen > 0) { 268 for (i = 0; i < sLen; i++) 269 *p++ ^= salt[i]; 270 } 271 if (MSBits) 272 EM[0] &= 0xFF >> (8 - MSBits); 273 274 /* H is already in place so just set final 0xbc */ 275 276 EM[emLen - 1] = 0xbc; 277 278 ret = 1; 279 280 err: 281 if (salt) 282 OPENSSL_free(salt); 283 284 return ret; 285 286} 287 288#if defined(_MSC_VER) 289# pragma optimize("",on) 290#endif 291