Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame^] | 1 | /* rsa_pss.c */ |
| 2 | /* Written by Dr Stephen N Henson (steve@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@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@cryptsoft.com). This product includes software written by Tim |
| 55 | * Hudson (tjh@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 |