crypto/asn1/a_verify.c

   1 /* crypto/asn1/a_verify.c */
   2 /* Copyright (C) 1995-1997 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 <time.h>
  61 #include <sys/types.h>
  62 #include <sys/stat.h>
  63
  64 #include "cryptlib.h"
  65 #include "bn.h"
  66 #include "x509.h"
  67 #include "objects.h"
  68 #include "buffer.h"
  69 #include "evp.h"
  70 #include "pem.h"
  71
  72 int ASN1_verify(i2d,a,signature,data,pkey)
  73 int (*i2d)();
  74 X509_ALGOR *a;
  75 ASN1_BIT_STRING *signature;
  76 char *data;
  77 EVP_PKEY *pkey;
  78         {
  79         EVP_MD_CTX ctx;
  80         EVP_MD *type;
  81         unsigned char *p,*buf_in=NULL;
  82         int ret= -1,i,inl;
  83
  84         i=OBJ_obj2nid(a->algorithm);
  85         type=EVP_get_digestbyname(OBJ_nid2sn(i));
  86         if (type == NULL)
  87                 {
  88                 ASN1err(ASN1_F_ASN1_VERIFY,ASN1_R_UNKNOWN_MESSAGE_DIGEST_ALGORITHM);
  89                 goto err;
  90                 }
  91
  92         inl=i2d(data,NULL);
  93         buf_in=(unsigned char *)Malloc((unsigned int)inl);
  94         if (buf_in == NULL)
  95                 {
  96                 ASN1err(ASN1_F_ASN1_VERIFY,ERR_R_MALLOC_FAILURE);
  97                 goto err;
  98                 }
  99         p=buf_in;
 100
 101         i2d(data,&p);
 102         EVP_VerifyInit(&ctx,type);
 103         EVP_VerifyUpdate(&ctx,(unsigned char *)buf_in,inl);
 104
 105         memset(buf_in,0,(unsigned int)inl);
 106         Free((char *)buf_in);
 107
 108         if (EVP_VerifyFinal(&ctx,(unsigned char *)signature->data,
 109                         (unsigned int)signature->length,pkey) <= 0)
 110                 {
 111                 ASN1err(ASN1_F_ASN1_VERIFY,ERR_R_EVP_LIB);
 112                 ret=0;
 113                 goto err;
 114                 }
 115         /* we don't need to zero the 'ctx' because we just checked
 116          * public information */
 117         /* memset(&ctx,0,sizeof(ctx)); */
 118         ret=1;
 119 err:
 120         return(ret);
 121         }