crypto/openssl/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 #ifdef OPENSSL_FIPS
  81         if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
  82                         && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW))
  83                 {
  84                 RSAerr(RSA_F_RSA_SIGN, RSA_R_NON_FIPS_RSA_METHOD);
  85                 return 0;
  86                 }
  87 #endif
  88         if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign)
  89                 {
  90                 return rsa->meth->rsa_sign(type, m, m_len,
  91                         sigret, siglen, rsa);
  92                 }
  93         /* Special case: SSL signature, just check the length */
  94         if(type == NID_md5_sha1) {
  95                 if(m_len != SSL_SIG_LENGTH) {
  96                         RSAerr(RSA_F_RSA_SIGN,RSA_R_INVALID_MESSAGE_LENGTH);
  97                         return(0);
  98                 }
  99                 i = SSL_SIG_LENGTH;
 100                 s = m;
 101         } else {
 102                 sig.algor= &algor;
 103                 sig.algor->algorithm=OBJ_nid2obj(type);
 104                 if (sig.algor->algorithm == NULL)
 105                         {
 106                         RSAerr(RSA_F_RSA_SIGN,RSA_R_UNKNOWN_ALGORITHM_TYPE);
 107                         return(0);
 108                         }
 109                 if (sig.algor->algorithm->length == 0)
 110                         {
 111                         RSAerr(RSA_F_RSA_SIGN,RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);
 112                         return(0);
 113                         }
 114                 parameter.type=V_ASN1_NULL;
 115                 parameter.value.ptr=NULL;
 116                 sig.algor->parameter= &parameter;
 117
 118                 sig.digest= &digest;
 119                 sig.digest->data=(unsigned char *)m; /* TMP UGLY CAST */
 120                 sig.digest->length=m_len;
 121
 122                 i=i2d_X509_SIG(&sig,NULL);
 123         }
 124         j=RSA_size(rsa);
 125         if (i > (j-RSA_PKCS1_PADDING_SIZE))
 126                 {
 127                 RSAerr(RSA_F_RSA_SIGN,RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
 128                 return(0);
 129                 }
 130         if(type != NID_md5_sha1) {
 131                 tmps=(unsigned char *)OPENSSL_malloc((unsigned int)j+1);
 132                 if (tmps == NULL)
 133                         {
 134                         RSAerr(RSA_F_RSA_SIGN,ERR_R_MALLOC_FAILURE);
 135                         return(0);
 136                         }
 137                 p=tmps;
 138                 i2d_X509_SIG(&sig,&p);
 139                 s=tmps;
 140         }
 141         i=RSA_private_encrypt(i,s,sigret,rsa,RSA_PKCS1_PADDING);
 142         if (i <= 0)
 143                 ret=0;
 144         else
 145                 *siglen=i;
 146
 147         if(type != NID_md5_sha1) {
 148                 OPENSSL_cleanse(tmps,(unsigned int)j+1);
 149                 OPENSSL_free(tmps);
 150         }
 151         return(ret);
 152         }
 153
 154 int int_rsa_verify(int dtype, const unsigned char *m,
 155                           unsigned int m_len,
 156                           unsigned char *rm, size_t *prm_len,
 157                           const unsigned char *sigbuf, size_t siglen,
 158                           RSA *rsa)
 159         {
 160         int i,ret=0,sigtype;
 161         unsigned char *s;
 162         X509_SIG *sig=NULL;
 163
 164 #ifdef OPENSSL_FIPS
 165         if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
 166                         && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW))
 167                 {
 168                 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_NON_FIPS_RSA_METHOD);
 169                 return 0;
 170                 }
 171 #endif
 172
 173         if (siglen != (unsigned int)RSA_size(rsa))
 174                 {
 175                 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH);
 176                 return(0);
 177                 }
 178
 179         if((dtype == NID_md5_sha1) && rm)
 180                 {
 181                 i = RSA_public_decrypt((int)siglen,
 182                                         sigbuf,rm,rsa,RSA_PKCS1_PADDING);
 183                 if (i <= 0)
 184                         return 0;
 185                 *prm_len = i;
 186                 return 1;
 187                 }
 188
 189         s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen);
 190         if (s == NULL)
 191                 {
 192                 RSAerr(RSA_F_INT_RSA_VERIFY,ERR_R_MALLOC_FAILURE);
 193                 goto err;
 194                 }
 195         if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) {
 196                         RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH);
 197                         goto err;
 198         }
 199         i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING);
 200
 201         if (i <= 0) goto err;
 202         /* Oddball MDC2 case: signature can be OCTET STRING.
 203          * check for correct tag and length octets.
 204          */
 205         if (dtype == NID_mdc2 && i == 18 && s[0] == 0x04 && s[1] == 0x10)
 206                 {
 207                 if (rm)
 208                         {
 209                         memcpy(rm, s + 2, 16);
 210                         *prm_len = 16;
 211                         ret = 1;
 212                         }
 213                 else if(memcmp(m, s + 2, 16))
 214                         RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
 215                 else
 216                         ret = 1;
 217                 }
 218
 219         /* Special case: SSL signature */
 220         if(dtype == NID_md5_sha1) {
 221                 if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH))
 222                                 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
 223                 else ret = 1;
 224         } else {
 225                 const unsigned char *p=s;
 226                 sig=d2i_X509_SIG(NULL,&p,(long)i);
 227
 228                 if (sig == NULL) goto err;
 229
 230                 /* Excess data can be used to create forgeries */
 231                 if(p != s+i)
 232                         {
 233                         RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
 234                         goto err;
 235                         }
 236
 237                 /* Parameters to the signature algorithm can also be used to
 238                    create forgeries */
 239                 if(sig->algor->parameter
 240                    && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL)
 241                         {
 242                         RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
 243                         goto err;
 244                         }
 245
 246                 sigtype=OBJ_obj2nid(sig->algor->algorithm);
 247
 248
 249         #ifdef RSA_DEBUG
 250                 /* put a backward compatibility flag in EAY */
 251                 fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype),
 252                         OBJ_nid2ln(dtype));
 253         #endif
 254                 if (sigtype != dtype)
 255                         {
 256                         if (((dtype == NID_md5) &&
 257                                 (sigtype == NID_md5WithRSAEncryption)) ||
 258                                 ((dtype == NID_md2) &&
 259                                 (sigtype == NID_md2WithRSAEncryption)))
 260                                 {
 261                                 /* ok, we will let it through */
 262 #if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16)
 263                                 fprintf(stderr,"signature has problems, re-make with post SSLeay045\n");
 264 #endif
 265                                 }
 266                         else
 267                                 {
 268                                 RSAerr(RSA_F_INT_RSA_VERIFY,
 269                                                 RSA_R_ALGORITHM_MISMATCH);
 270                                 goto err;
 271                                 }
 272                         }
 273                 if (rm)
 274                         {
 275                         const EVP_MD *md;
 276                         md = EVP_get_digestbynid(dtype);
 277                         if (md && (EVP_MD_size(md) != sig->digest->length))
 278                                 RSAerr(RSA_F_INT_RSA_VERIFY,
 279                                                 RSA_R_INVALID_DIGEST_LENGTH);
 280                         else
 281                                 {
 282                                 memcpy(rm, sig->digest->data,
 283                                                         sig->digest->length);
 284                                 *prm_len = sig->digest->length;
 285                                 ret = 1;
 286                                 }
 287                         }
 288                 else if (((unsigned int)sig->digest->length != m_len) ||
 289                         (memcmp(m,sig->digest->data,m_len) != 0))
 290                         {
 291                         RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
 292                         }
 293                 else
 294                         ret=1;
 295         }
 296 err:
 297         if (sig != NULL) X509_SIG_free(sig);
 298         if (s != NULL)
 299                 {
 300                 OPENSSL_cleanse(s,(unsigned int)siglen);
 301                 OPENSSL_free(s);
 302                 }
 303         return(ret);
 304         }
 305
 306 int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
 307                 const unsigned char *sigbuf, unsigned int siglen,
 308                 RSA *rsa)
 309         {
 310
 311         if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify)
 312                 {
 313                 return rsa->meth->rsa_verify(dtype, m, m_len,
 314                         sigbuf, siglen, rsa);
 315                 }
 316
 317         return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa);
 318         }