crypto/rsa/rsa_pss.c

   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 #include "rsa_locl.h"
  68
  69 static const unsigned char zeroes[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
  70
  71 #if defined(_MSC_VER) && defined(_ARM_)
  72 # pragma optimize("g", off)
  73 #endif
  74
  75 int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash,
  76                          const EVP_MD *Hash, const unsigned char *EM,
  77                          int sLen)
  78 {
  79     return RSA_verify_PKCS1_PSS_mgf1(rsa, mHash, Hash, NULL, EM, sLen);
  80 }
  81
  82 int RSA_verify_PKCS1_PSS_mgf1(RSA *rsa, const unsigned char *mHash,
  83                               const EVP_MD *Hash, const EVP_MD *mgf1Hash,
  84                               const unsigned char *EM, int sLen)
  85 {
  86     int i;
  87     int ret = 0;
  88     int hLen, maskedDBLen, MSBits, emLen;
  89     const unsigned char *H;
  90     unsigned char *DB = NULL;
  91     EVP_MD_CTX ctx;
  92     unsigned char H_[EVP_MAX_MD_SIZE];
  93     EVP_MD_CTX_init(&ctx);
  94
  95     if (mgf1Hash == NULL)
  96         mgf1Hash = Hash;
  97
  98     hLen = M_EVP_MD_size(Hash);
  99     if (hLen < 0)
 100         goto err;
 101     /*-
 102      * Negative sLen has special meanings:
 103      *      -1      sLen == hLen
 104      *      -2      salt length is autorecovered from signature
 105      *      -N      reserved
 106      */
 107     if (sLen == -1)
 108         sLen = hLen;
 109     else if (sLen == -2)
 110         sLen = -2;
 111     else if (sLen < -2) {
 112         RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
 113         goto err;
 114     }
 115
 116     MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
 117     emLen = RSA_size(rsa);
 118     if (EM[0] & (0xFF << MSBits)) {
 119         RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_FIRST_OCTET_INVALID);
 120         goto err;
 121     }
 122     if (MSBits == 0) {
 123         EM++;
 124         emLen--;
 125     }
 126     if (emLen < (hLen + sLen + 2)) { /* sLen can be small negative */
 127         RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_DATA_TOO_LARGE);
 128         goto err;
 129     }
 130     if (EM[emLen - 1] != 0xbc) {
 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         RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, ERR_R_MALLOC_FAILURE);
 139         goto err;
 140     }
 141     if (PKCS1_MGF1(DB, maskedDBLen, H, hLen, mgf1Hash) < 0)
 142         goto err;
 143     for (i = 0; i < maskedDBLen; i++)
 144         DB[i] ^= EM[i];
 145     if (MSBits)
 146         DB[0] &= 0xFF >> (8 - MSBits);
 147     for (i = 0; DB[i] == 0 && i < (maskedDBLen - 1); i++) ;
 148     if (DB[i++] != 0x1) {
 149         RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_RECOVERY_FAILED);
 150         goto err;
 151     }
 152     if (sLen >= 0 && (maskedDBLen - i) != sLen) {
 153         RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
 154         goto err;
 155     }
 156     if (!EVP_DigestInit_ex(&ctx, Hash, NULL)
 157         || !EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes)
 158         || !EVP_DigestUpdate(&ctx, mHash, hLen))
 159         goto err;
 160     if (maskedDBLen - i) {
 161         if (!EVP_DigestUpdate(&ctx, DB + i, maskedDBLen - i))
 162             goto err;
 163     }
 164     if (!EVP_DigestFinal_ex(&ctx, H_, NULL))
 165         goto err;
 166     if (memcmp(H_, H, hLen)) {
 167         RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_BAD_SIGNATURE);
 168         ret = 0;
 169     } else
 170         ret = 1;
 171
 172  err:
 173     OPENSSL_free(DB);
 174     EVP_MD_CTX_cleanup(&ctx);
 175
 176     return ret;
 177
 178 }
 179
 180 int 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
 187 int 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 = M_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     OPENSSL_free(salt);
 282
 283     return ret;
 284
 285 }
 286
 287 #if defined(_MSC_VER)
 288 # pragma optimize("",on)
 289 #endif