crypto/rsa/rsa_sign.c

   1 /* crypto/rsa/rsa_sign.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include "cryptlib.h"
  61 #include <openssl/bn.h>
  62 #include <openssl/rsa.h>
  63 #include <openssl/objects.h>
  64 #include <openssl/x509.h>
  65
  66 /* Size of an SSL signature: MD5+SHA1 */
  67 #define SSL_SIG_LENGTH  36
  68
  69 int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
  70              unsigned char *sigret, unsigned int *siglen, RSA *rsa)
  71         {
  72         X509_SIG sig;
  73         ASN1_TYPE parameter;
  74         int i,j,ret=1;
  75         unsigned char *p, *tmps = NULL;
  76         const unsigned char *s = NULL;
  77         X509_ALGOR algor;
  78         ASN1_OCTET_STRING digest;
  79         if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign)
  80                 {
  81                 return rsa->meth->rsa_sign(type, m, m_len,
  82                         sigret, siglen, rsa);
  83                 }
  84         /* Special case: SSL signature, just check the length */
  85         if(type == NID_md5_sha1) {
  86                 if(m_len != SSL_SIG_LENGTH) {
  87                         RSAerr(RSA_F_RSA_SIGN,RSA_R_INVALID_MESSAGE_LENGTH);
  88                         return(0);
  89                 }
  90                 i = SSL_SIG_LENGTH;
  91                 s = m;
  92         } else {
  93                 sig.algor= &algor;
  94                 sig.algor->algorithm=OBJ_nid2obj(type);
  95                 if (sig.algor->algorithm == NULL)
  96                         {
  97                         RSAerr(RSA_F_RSA_SIGN,RSA_R_UNKNOWN_ALGORITHM_TYPE);
  98                         return(0);
  99                         }
 100                 if (sig.algor->algorithm->length == 0)
 101                         {
 102                         RSAerr(RSA_F_RSA_SIGN,RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);
 103                         return(0);
 104                         }
 105                 parameter.type=V_ASN1_NULL;
 106                 parameter.value.ptr=NULL;
 107                 sig.algor->parameter= &parameter;
 108
 109                 sig.digest= &digest;
 110                 sig.digest->data=(unsigned char *)m; /* TMP UGLY CAST */
 111                 sig.digest->length=m_len;
 112
 113                 i=i2d_X509_SIG(&sig,NULL);
 114         }
 115         j=RSA_size(rsa);
 116         if (i > (j-RSA_PKCS1_PADDING_SIZE))
 117                 {
 118                 RSAerr(RSA_F_RSA_SIGN,RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
 119                 return(0);
 120                 }
 121         if(type != NID_md5_sha1) {
 122                 tmps=(unsigned char *)OPENSSL_malloc((unsigned int)j+1);
 123                 if (tmps == NULL)
 124                         {
 125                         RSAerr(RSA_F_RSA_SIGN,ERR_R_MALLOC_FAILURE);
 126                         return(0);
 127                         }
 128                 p=tmps;
 129                 i2d_X509_SIG(&sig,&p);
 130                 s=tmps;
 131         }
 132         i=RSA_private_encrypt(i,s,sigret,rsa,RSA_PKCS1_PADDING);
 133         if (i <= 0)
 134                 ret=0;
 135         else
 136                 *siglen=i;
 137
 138         if(type != NID_md5_sha1) {
 139                 OPENSSL_cleanse(tmps,(unsigned int)j+1);
 140                 OPENSSL_free(tmps);
 141         }
 142         return(ret);
 143         }
 144
 145 int int_rsa_verify(int dtype, const unsigned char *m, unsigned int m_len,
 146                 unsigned char *rm, unsigned int *prm_len,
 147                 unsigned char *sigbuf, unsigned int siglen,
 148                 RSA *rsa)
 149         {
 150         int i,ret=0,sigtype;
 151         unsigned char *s;
 152         X509_SIG *sig=NULL;
 153
 154         if (siglen != (unsigned int)RSA_size(rsa))
 155                 {
 156                 RSAerr(RSA_F_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH);
 157                 return(0);
 158                 }
 159
 160         if((dtype == NID_md5_sha1) && rm)
 161                 {
 162                 i = RSA_public_decrypt((int)siglen,
 163                                         sigbuf,rm,rsa,RSA_PKCS1_PADDING);
 164                 if (i <= 0)
 165                         return 0;
 166                 *prm_len = i;
 167                 return 1;
 168                 }
 169
 170         s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen);
 171         if (s == NULL)
 172                 {
 173                 RSAerr(RSA_F_RSA_VERIFY,ERR_R_MALLOC_FAILURE);
 174                 goto err;
 175                 }
 176         if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) {
 177                         RSAerr(RSA_F_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH);
 178                         goto err;
 179         }
 180         i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING);
 181
 182         if (i <= 0) goto err;
 183
 184         /* Special case: SSL signature */
 185         if(dtype == NID_md5_sha1) {
 186                 if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH))
 187                                 RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
 188                 else ret = 1;
 189         } else {
 190                 const unsigned char *p=s;
 191                 sig=d2i_X509_SIG(NULL,&p,(long)i);
 192
 193                 if (sig == NULL) goto err;
 194                 sigtype=OBJ_obj2nid(sig->algor->algorithm);
 195
 196
 197         #ifdef RSA_DEBUG
 198                 /* put a backward compatibility flag in EAY */
 199                 fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype),
 200                         OBJ_nid2ln(dtype));
 201         #endif
 202                 if (sigtype != dtype)
 203                         {
 204                         if (((dtype == NID_md5) &&
 205                                 (sigtype == NID_md5WithRSAEncryption)) ||
 206                                 ((dtype == NID_md2) &&
 207                                 (sigtype == NID_md2WithRSAEncryption)))
 208                                 {
 209                                 /* ok, we will let it through */
 210 #if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16)
 211                                 fprintf(stderr,"signature has problems, re-make with post SSLeay045\n");
 212 #endif
 213                                 }
 214                         else
 215                                 {
 216                                 RSAerr(RSA_F_RSA_VERIFY,
 217                                                 RSA_R_ALGORITHM_MISMATCH);
 218                                 goto err;
 219                                 }
 220                         }
 221                 if (rm)
 222                         {
 223                         const EVP_MD *md;
 224                         md = EVP_get_digestbynid(dtype);
 225                         if (md && (EVP_MD_size(md) != sig->digest->length))
 226                                 RSAerr(RSA_F_RSA_VERIFY,
 227                                                 RSA_R_INVALID_DIGEST_LENGTH);
 228                         else
 229                                 {
 230                                 memcpy(rm, sig->digest->data,
 231                                                         sig->digest->length);
 232                                 *prm_len = sig->digest->length;
 233                                 ret = 1;
 234                                 }
 235                         }
 236                 else if (((unsigned int)sig->digest->length != m_len) ||
 237                         (memcmp(m,sig->digest->data,m_len) != 0))
 238                         {
 239                         RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
 240                         }
 241                 else
 242                         ret=1;
 243         }
 244 err:
 245         if (sig != NULL) X509_SIG_free(sig);
 246         if (s != NULL)
 247                 {
 248                 OPENSSL_cleanse(s,(unsigned int)siglen);
 249                 OPENSSL_free(s);
 250                 }
 251         return(ret);
 252         }
 253
 254 int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
 255                 unsigned char *sigbuf, unsigned int siglen,
 256                 RSA *rsa)
 257         {
 258
 259         if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify)
 260                 {
 261                 return rsa->meth->rsa_verify(dtype, m, m_len,
 262                         sigbuf, siglen, rsa);
 263                 }
 264
 265         return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa);
 266         }