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 #include "rsa_locl.h"
  66
  67 /* Size of an SSL signature: MD5+SHA1 */
  68 #define SSL_SIG_LENGTH  36
  69
  70 int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
  71              unsigned char *sigret, unsigned int *siglen, RSA *rsa)
  72         {
  73         X509_SIG sig;
  74         ASN1_TYPE parameter;
  75         int i,j,ret=1;
  76         unsigned char *p, *tmps = NULL;
  77         const unsigned char *s = NULL;
  78         X509_ALGOR algor;
  79         ASN1_OCTET_STRING digest;
  80         if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign)
  81                 {
  82                 return rsa->meth->rsa_sign(type, m, m_len,
  83                         sigret, siglen, rsa);
  84                 }
  85         /* Special case: SSL signature, just check the length */
  86         if(type == NID_md5_sha1) {
  87                 if(m_len != SSL_SIG_LENGTH) {
  88                         RSAerr(RSA_F_RSA_SIGN,RSA_R_INVALID_MESSAGE_LENGTH);
  89                         return(0);
  90                 }
  91                 i = SSL_SIG_LENGTH;
  92                 s = m;
  93         } else {
  94                 sig.algor= &algor;
  95                 sig.algor->algorithm=OBJ_nid2obj(type);
  96                 if (sig.algor->algorithm == NULL)
  97                         {
  98                         RSAerr(RSA_F_RSA_SIGN,RSA_R_UNKNOWN_ALGORITHM_TYPE);
  99                         return(0);
 100                         }
 101                 if (sig.algor->algorithm->length == 0)
 102                         {
 103                         RSAerr(RSA_F_RSA_SIGN,RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);
 104                         return(0);
 105                         }
 106                 parameter.type=V_ASN1_NULL;
 107                 parameter.value.ptr=NULL;
 108                 sig.algor->parameter= &parameter;
 109
 110                 sig.digest= &digest;
 111                 sig.digest->data=(unsigned char *)m; /* TMP UGLY CAST */
 112                 sig.digest->length=m_len;
 113
 114                 i=i2d_X509_SIG(&sig,NULL);
 115         }
 116         j=RSA_size(rsa);
 117         if (i > (j-RSA_PKCS1_PADDING_SIZE))
 118                 {
 119                 RSAerr(RSA_F_RSA_SIGN,RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
 120                 return(0);
 121                 }
 122         if(type != NID_md5_sha1) {
 123                 tmps=(unsigned char *)OPENSSL_malloc((unsigned int)j+1);
 124                 if (tmps == NULL)
 125                         {
 126                         RSAerr(RSA_F_RSA_SIGN,ERR_R_MALLOC_FAILURE);
 127                         return(0);
 128                         }
 129                 p=tmps;
 130                 i2d_X509_SIG(&sig,&p);
 131                 s=tmps;
 132         }
 133         i=RSA_private_encrypt(i,s,sigret,rsa,RSA_PKCS1_PADDING);
 134         if (i <= 0)
 135                 ret=0;
 136         else
 137                 *siglen=i;
 138
 139         if(type != NID_md5_sha1) {
 140                 OPENSSL_cleanse(tmps,(unsigned int)j+1);
 141                 OPENSSL_free(tmps);
 142         }
 143         return(ret);
 144         }
 145
 146 int int_rsa_verify(int dtype, const unsigned char *m,
 147                           unsigned int m_len,
 148                           unsigned char *rm, size_t *prm_len,
 149                           const unsigned char *sigbuf, size_t siglen,
 150                           RSA *rsa)
 151         {
 152         int i,ret=0,sigtype;
 153         unsigned char *s;
 154         X509_SIG *sig=NULL;
 155
 156         if (siglen != (unsigned int)RSA_size(rsa))
 157                 {
 158                 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH);
 159                 return(0);
 160                 }
 161
 162         if((dtype == NID_md5_sha1) && rm)
 163                 {
 164                 i = RSA_public_decrypt((int)siglen,
 165                                         sigbuf,rm,rsa,RSA_PKCS1_PADDING);
 166                 if (i <= 0)
 167                         return 0;
 168                 *prm_len = i;
 169                 return 1;
 170                 }
 171
 172         s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen);
 173         if (s == NULL)
 174                 {
 175                 RSAerr(RSA_F_INT_RSA_VERIFY,ERR_R_MALLOC_FAILURE);
 176                 goto err;
 177                 }
 178         if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) {
 179                         RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH);
 180                         goto err;
 181         }
 182         i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING);
 183
 184         if (i <= 0) goto err;
 185
 186         /* Special case: SSL signature */
 187         if(dtype == NID_md5_sha1) {
 188                 if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH))
 189                                 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
 190                 else ret = 1;
 191         } else {
 192                 const unsigned char *p=s;
 193                 sig=d2i_X509_SIG(NULL,&p,(long)i);
 194
 195                 if (sig == NULL) goto err;
 196
 197                 /* Excess data can be used to create forgeries */
 198                 if(p != s+i)
 199                         {
 200                         RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
 201                         goto err;
 202                         }
 203
 204                 /* Parameters to the signature algorithm can also be used to
 205                    create forgeries */
 206                 if(sig->algor->parameter
 207                    && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL)
 208                         {
 209                         RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
 210                         goto err;
 211                         }
 212
 213                 sigtype=OBJ_obj2nid(sig->algor->algorithm);
 214
 215
 216         #ifdef RSA_DEBUG
 217                 /* put a backward compatibility flag in EAY */
 218                 fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype),
 219                         OBJ_nid2ln(dtype));
 220         #endif
 221                 if (sigtype != dtype)
 222                         {
 223                         if (((dtype == NID_md5) &&
 224                                 (sigtype == NID_md5WithRSAEncryption)) ||
 225                                 ((dtype == NID_md2) &&
 226                                 (sigtype == NID_md2WithRSAEncryption)))
 227                                 {
 228                                 /* ok, we will let it through */
 229 #if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16)
 230                                 fprintf(stderr,"signature has problems, re-make with post SSLeay045\n");
 231 #endif
 232                                 }
 233                         else
 234                                 {
 235                                 RSAerr(RSA_F_INT_RSA_VERIFY,
 236                                                 RSA_R_ALGORITHM_MISMATCH);
 237                                 goto err;
 238                                 }
 239                         }
 240                 if (rm)
 241                         {
 242                         const EVP_MD *md;
 243                         md = EVP_get_digestbynid(dtype);
 244                         if (md && (EVP_MD_size(md) != sig->digest->length))
 245                                 RSAerr(RSA_F_INT_RSA_VERIFY,
 246                                                 RSA_R_INVALID_DIGEST_LENGTH);
 247                         else
 248                                 {
 249                                 memcpy(rm, sig->digest->data,
 250                                                         sig->digest->length);
 251                                 *prm_len = sig->digest->length;
 252                                 ret = 1;
 253                                 }
 254                         }
 255                 else if (((unsigned int)sig->digest->length != m_len) ||
 256                         (memcmp(m,sig->digest->data,m_len) != 0))
 257                         {
 258                         RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
 259                         }
 260                 else
 261                         ret=1;
 262         }
 263 err:
 264         if (sig != NULL) X509_SIG_free(sig);
 265         if (s != NULL)
 266                 {
 267                 OPENSSL_cleanse(s,(unsigned int)siglen);
 268                 OPENSSL_free(s);
 269                 }
 270         return(ret);
 271         }
 272
 273 int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
 274                 const unsigned char *sigbuf, unsigned int siglen,
 275                 RSA *rsa)
 276         {
 277
 278         if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify)
 279                 {
 280                 return rsa->meth->rsa_verify(dtype, m, m_len,
 281                         sigbuf, siglen, rsa);
 282                 }
 283
 284         return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa);
 285         }