1 /* rsa_pss.c */ 2 /* Written by Dr Stephen N Henson (steve (at) openssl.org) for the OpenSSL 3 * project 2005. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 2005 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing (at) OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay (at) cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh (at) cryptsoft.com). 56 * 57 */ 58 59 #include <stdio.h> 60 #include "cryptlib.h" 61 #include <openssl/bn.h> 62 #include <openssl/rsa.h> 63 #include <openssl/evp.h> 64 #include <openssl/rand.h> 65 #include <openssl/sha.h> 66 67 static const unsigned char zeroes[] = {0,0,0,0,0,0,0,0}; 68 69 #if defined(_MSC_VER) && defined(_ARM_) 70 #pragma optimize("g", off) 71 #endif 72 73 int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash, 74 const EVP_MD *Hash, const unsigned char *EM, int sLen) 75 { 76 return RSA_verify_PKCS1_PSS_mgf1(rsa, mHash, Hash, NULL, EM, sLen); 77 } 78 79 int RSA_verify_PKCS1_PSS_mgf1(RSA *rsa, const unsigned char *mHash, 80 const EVP_MD *Hash, const EVP_MD *mgf1Hash, 81 const unsigned char *EM, int sLen) 82 { 83 int i; 84 int ret = 0; 85 int hLen, maskedDBLen, MSBits, emLen; 86 const unsigned char *H; 87 unsigned char *DB = NULL; 88 EVP_MD_CTX ctx; 89 unsigned char H_[EVP_MAX_MD_SIZE]; 90 EVP_MD_CTX_init(&ctx); 91 92 if (mgf1Hash == NULL) 93 mgf1Hash = Hash; 94 95 hLen = EVP_MD_size(Hash); 96 if (hLen < 0) 97 goto err; 98 /* 99 * Negative sLen has special meanings: 100 * -1 sLen == hLen 101 * -2 salt length is autorecovered from signature 102 * -N reserved 103 */ 104 if (sLen == -1) sLen = hLen; 105 else if (sLen == -2) sLen = -2; 106 else if (sLen < -2) 107 { 108 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED); 109 goto err; 110 } 111 112 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7; 113 emLen = RSA_size(rsa); 114 if (EM[0] & (0xFF << MSBits)) 115 { 116 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_FIRST_OCTET_INVALID); 117 goto err; 118 } 119 if (MSBits == 0) 120 { 121 EM++; 122 emLen--; 123 } 124 if (emLen < (hLen + sLen + 2)) /* sLen can be small negative */ 125 { 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 { 131 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_LAST_OCTET_INVALID); 132 goto err; 133 } 134 maskedDBLen = emLen - hLen - 1; 135 H = EM + maskedDBLen; 136 DB = OPENSSL_malloc(maskedDBLen); 137 if (!DB) 138 { 139 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, ERR_R_MALLOC_FAILURE); 140 goto err; 141 } 142 if (PKCS1_MGF1(DB, maskedDBLen, H, hLen, mgf1Hash) < 0) 143 goto err; 144 for (i = 0; i < maskedDBLen; i++) 145 DB[i] ^= EM[i]; 146 if (MSBits) 147 DB[0] &= 0xFF >> (8 - MSBits); 148 for (i = 0; DB[i] == 0 && i < (maskedDBLen-1); i++) ; 149 if (DB[i++] != 0x1) 150 { 151 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_RECOVERY_FAILED); 152 goto err; 153 } 154 if (sLen >= 0 && (maskedDBLen - i) != sLen) 155 { 156 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED); 157 goto err; 158 } 159 if (!EVP_DigestInit_ex(&ctx, Hash, NULL) 160 || !EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes) 161 || !EVP_DigestUpdate(&ctx, mHash, hLen)) 162 goto err; 163 if (maskedDBLen - i) 164 { 165 if (!EVP_DigestUpdate(&ctx, DB + i, maskedDBLen - i)) 166 goto err; 167 } 168 if (!EVP_DigestFinal_ex(&ctx, H_, NULL)) 169 goto err; 170 if (memcmp(H_, H, hLen)) 171 { 172 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_BAD_SIGNATURE); 173 ret = 0; 174 } 175 else 176 ret = 1; 177 178 err: 179 if (DB) 180 OPENSSL_free(DB); 181 EVP_MD_CTX_cleanup(&ctx); 182 183 return ret; 184 185 } 186 187 int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM, 188 const unsigned char *mHash, 189 const EVP_MD *Hash, int sLen) 190 { 191 return RSA_padding_add_PKCS1_PSS_mgf1(rsa, EM, mHash, Hash, NULL, sLen); 192 } 193 194 int RSA_padding_add_PKCS1_PSS_mgf1(RSA *rsa, unsigned char *EM, 195 const unsigned char *mHash, 196 const EVP_MD *Hash, const EVP_MD *mgf1Hash, int sLen) 197 { 198 int i; 199 int ret = 0; 200 int hLen, maskedDBLen, MSBits, emLen; 201 unsigned char *H, *salt = NULL, *p; 202 EVP_MD_CTX ctx; 203 204 if (mgf1Hash == NULL) 205 mgf1Hash = Hash; 206 207 hLen = EVP_MD_size(Hash); 208 if (hLen < 0) 209 goto err; 210 /* 211 * Negative sLen has special meanings: 212 * -1 sLen == hLen 213 * -2 salt length is maximized 214 * -N reserved 215 */ 216 if (sLen == -1) sLen = hLen; 217 else if (sLen == -2) sLen = -2; 218 else if (sLen < -2) 219 { 220 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED); 221 goto err; 222 } 223 224 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7; 225 emLen = RSA_size(rsa); 226 if (MSBits == 0) 227 { 228 *EM++ = 0; 229 emLen--; 230 } 231 if (sLen == -2) 232 { 233 sLen = emLen - hLen - 2; 234 } 235 else if (emLen < (hLen + sLen + 2)) 236 { 237 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); 238 goto err; 239 } 240 if (sLen > 0) 241 { 242 salt = OPENSSL_malloc(sLen); 243 if (!salt) 244 { 245 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,ERR_R_MALLOC_FAILURE); 246 goto err; 247 } 248 if (RAND_bytes(salt, sLen) <= 0) 249 goto err; 250 } 251 maskedDBLen = emLen - hLen - 1; 252 H = EM + maskedDBLen; 253 EVP_MD_CTX_init(&ctx); 254 if (!EVP_DigestInit_ex(&ctx, Hash, NULL) 255 || !EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes) 256 || !EVP_DigestUpdate(&ctx, mHash, hLen)) 257 goto err; 258 if (sLen && !EVP_DigestUpdate(&ctx, salt, sLen)) 259 goto err; 260 if (!EVP_DigestFinal_ex(&ctx, H, NULL)) 261 goto err; 262 EVP_MD_CTX_cleanup(&ctx); 263 264 /* Generate dbMask in place then perform XOR on it */ 265 if (PKCS1_MGF1(EM, maskedDBLen, H, hLen, mgf1Hash)) 266 goto err; 267 268 p = EM; 269 270 /* Initial PS XORs with all zeroes which is a NOP so just update 271 * pointer. Note from a test above this value is guaranteed to 272 * be non-negative. 273 */ 274 p += emLen - sLen - hLen - 2; 275 *p++ ^= 0x1; 276 if (sLen > 0) 277 { 278 for (i = 0; i < sLen; i++) 279 *p++ ^= salt[i]; 280 } 281 if (MSBits) 282 EM[0] &= 0xFF >> (8 - MSBits); 283 284 /* H is already in place so just set final 0xbc */ 285 286 EM[emLen - 1] = 0xbc; 287 288 ret = 1; 289 290 err: 291 if (salt) 292 OPENSSL_free(salt); 293 294 return ret; 295 296 } 297 298 #if defined(_MSC_VER) 299 #pragma optimize("",on) 300 #endif 301
