crypto/rsa/rsa_pss.c

   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 #define OPENSSL_FIPSAPI
  60
  61 #include <stdio.h>
  62 #include "cryptlib.h"
  63 #include <openssl/bn.h>
  64 #include <openssl/rsa.h>
  65 #include <openssl/evp.h>
  66 #include <openssl/rand.h>
  67 #include <openssl/sha.h>
  68 #include "rsa_locl.h"
  69
  70 #ifdef OPENSSL_FIPS
  71 #include <openssl/fips.h>
  72 #endif
  73
  74 static const unsigned char zeroes[] = {0,0,0,0,0,0,0,0};
  75
  76 #if defined(_MSC_VER) && defined(_ARM_)
  77 #pragma optimize("g", off)
  78 #endif
  79
  80 int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash,
  81                         const EVP_MD *Hash, const unsigned char *EM, int sLen)
  82         {
  83         return RSA_verify_PKCS1_PSS_mgf1(rsa, mHash, Hash, NULL, EM, sLen);
  84         }
  85
  86 int RSA_verify_PKCS1_PSS_mgf1(RSA *rsa, const unsigned char *mHash,
  87                         const EVP_MD *Hash, const EVP_MD *mgf1Hash,
  88                         const unsigned char *EM, int sLen)
  89         {
  90         int i;
  91         int ret = 0;
  92         int hLen, maskedDBLen, MSBits, emLen;
  93         const unsigned char *H;
  94         unsigned char *DB = NULL;
  95         EVP_MD_CTX ctx;
  96         unsigned char H_[EVP_MAX_MD_SIZE];
  97         EVP_MD_CTX_init(&ctx);
  98
  99         if (mgf1Hash == NULL)
 100                 mgf1Hash = Hash;
 101
 102         hLen = M_EVP_MD_size(Hash);
 103         if (hLen < 0)
 104                 goto err;
 105         /*
 106          * Negative sLen has special meanings:
 107          *      -1      sLen == hLen
 108          *      -2      salt length is autorecovered from signature
 109          *      -N      reserved
 110          */
 111         if      (sLen == -1)    sLen = hLen;
 112         else if (sLen == -2)    sLen = -2;
 113         else if (sLen < -2)
 114                 {
 115                 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
 116                 goto err;
 117                 }
 118
 119         MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
 120         emLen = RSA_size(rsa);
 121         if (EM[0] & (0xFF << MSBits))
 122                 {
 123                 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_FIRST_OCTET_INVALID);
 124                 goto err;
 125                 }
 126         if (MSBits == 0)
 127                 {
 128                 EM++;
 129                 emLen--;
 130                 }
 131         if (emLen < (hLen + sLen + 2)) /* sLen can be small negative */
 132                 {
 133                 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_DATA_TOO_LARGE);
 134                 goto err;
 135                 }
 136         if (EM[emLen - 1] != 0xbc)
 137                 {
 138                 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_LAST_OCTET_INVALID);
 139                 goto err;
 140                 }
 141         maskedDBLen = emLen - hLen - 1;
 142         H = EM + maskedDBLen;
 143         DB = OPENSSL_malloc(maskedDBLen);
 144         if (!DB)
 145                 {
 146                 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, ERR_R_MALLOC_FAILURE);
 147                 goto err;
 148                 }
 149         if (PKCS1_MGF1(DB, maskedDBLen, H, hLen, mgf1Hash) < 0)
 150                 goto err;
 151         for (i = 0; i < maskedDBLen; i++)
 152                 DB[i] ^= EM[i];
 153         if (MSBits)
 154                 DB[0] &= 0xFF >> (8 - MSBits);
 155         for (i = 0; DB[i] == 0 && i < (maskedDBLen-1); i++) ;
 156         if (DB[i++] != 0x1)
 157                 {
 158                 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_RECOVERY_FAILED);
 159                 goto err;
 160                 }
 161         if (sLen >= 0 && (maskedDBLen - i) != sLen)
 162                 {
 163                 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
 164                 goto err;
 165                 }
 166         if (!EVP_DigestInit_ex(&ctx, Hash, NULL)
 167                 || !EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes)
 168                 || !EVP_DigestUpdate(&ctx, mHash, hLen))
 169                 goto err;
 170         if (maskedDBLen - i)
 171                 {
 172                 if (!EVP_DigestUpdate(&ctx, DB + i, maskedDBLen - i))
 173                         goto err;
 174                 }
 175         if (!EVP_DigestFinal_ex(&ctx, H_, NULL))
 176                 goto err;
 177         if (memcmp(H_, H, hLen))
 178                 {
 179                 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_BAD_SIGNATURE);
 180                 ret = 0;
 181                 }
 182         else
 183                 ret = 1;
 184
 185         err:
 186         if (DB)
 187                 OPENSSL_free(DB);
 188         EVP_MD_CTX_cleanup(&ctx);
 189
 190         return ret;
 191
 192         }
 193
 194 int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM,
 195                         const unsigned char *mHash,
 196                         const EVP_MD *Hash, int sLen)
 197         {
 198         return RSA_padding_add_PKCS1_PSS_mgf1(rsa, EM, mHash, Hash, NULL, sLen);
 199         }
 200
 201 int RSA_padding_add_PKCS1_PSS_mgf1(RSA *rsa, unsigned char *EM,
 202                         const unsigned char *mHash,
 203                         const EVP_MD *Hash, const EVP_MD *mgf1Hash, int sLen)
 204         {
 205         int i;
 206         int ret = 0;
 207         int hLen, maskedDBLen, MSBits, emLen;
 208         unsigned char *H, *salt = NULL, *p;
 209         EVP_MD_CTX ctx;
 210
 211         if (mgf1Hash == NULL)
 212                 mgf1Hash = Hash;
 213
 214         hLen = M_EVP_MD_size(Hash);
 215         if (hLen < 0)
 216                 goto err;
 217         /*
 218          * Negative sLen has special meanings:
 219          *      -1      sLen == hLen
 220          *      -2      salt length is maximized
 221          *      -N      reserved
 222          */
 223         if      (sLen == -1)    sLen = hLen;
 224         else if (sLen == -2)    sLen = -2;
 225         else if (sLen < -2)
 226                 {
 227                 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
 228                 goto err;
 229                 }
 230
 231         MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
 232         emLen = RSA_size(rsa);
 233         if (MSBits == 0)
 234                 {
 235                 *EM++ = 0;
 236                 emLen--;
 237                 }
 238         if (sLen == -2)
 239                 {
 240                 sLen = emLen - hLen - 2;
 241                 }
 242         else if (emLen < (hLen + sLen + 2))
 243                 {
 244                 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
 245                 goto err;
 246                 }
 247         if (sLen > 0)
 248                 {
 249                 salt = OPENSSL_malloc(sLen);
 250                 if (!salt)
 251                         {
 252                         RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,ERR_R_MALLOC_FAILURE);
 253                         goto err;
 254                         }
 255                 if (RAND_bytes(salt, sLen) <= 0)
 256                         goto err;
 257                 }
 258         maskedDBLen = emLen - hLen - 1;
 259         H = EM + maskedDBLen;
 260         EVP_MD_CTX_init(&ctx);
 261         if (!EVP_DigestInit_ex(&ctx, Hash, NULL)
 262                 || !EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes)
 263                 || !EVP_DigestUpdate(&ctx, mHash, hLen))
 264                 goto err;
 265         if (sLen && !EVP_DigestUpdate(&ctx, salt, sLen))
 266                 goto err;
 267         if (!EVP_DigestFinal_ex(&ctx, H, NULL))
 268                 goto err;
 269         EVP_MD_CTX_cleanup(&ctx);
 270
 271         /* Generate dbMask in place then perform XOR on it */
 272         if (PKCS1_MGF1(EM, maskedDBLen, H, hLen, mgf1Hash))
 273                 goto err;
 274
 275         p = EM;
 276
 277         /* Initial PS XORs with all zeroes which is a NOP so just update
 278          * pointer. Note from a test above this value is guaranteed to
 279          * be non-negative.
 280          */
 281         p += emLen - sLen - hLen - 2;
 282         *p++ ^= 0x1;
 283         if (sLen > 0)
 284                 {
 285                 for (i = 0; i < sLen; i++)
 286                         *p++ ^= salt[i];
 287                 }
 288         if (MSBits)
 289                 EM[0] &= 0xFF >> (8 - MSBits);
 290
 291         /* H is already in place so just set final 0xbc */
 292
 293         EM[emLen - 1] = 0xbc;
 294
 295         ret = 1;
 296
 297         err:
 298         if (salt)
 299                 OPENSSL_free(salt);
 300
 301         return ret;
 302
 303         }
 304
 305 #if defined(_MSC_VER)
 306 #pragma optimize("",on)
 307 #endif