lib/libcrypto/ecdsa/ecs_vrf.c

   1 /* $OpenBSD: ecs_vrf.c,v 1.5 2015/02/08 13:35:07 jsing Exp $ */
   2 /*
   3  * Written by Nils Larsch for the OpenSSL project
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    openssl-core@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59 #include <string.h>
  60 #include <openssl/opensslconf.h>
  61
  62 #include "ecs_locl.h"
  63 #ifndef OPENSSL_NO_ENGINE
  64 #include <openssl/engine.h>
  65 #endif
  66
  67 /* returns
  68  *      1: correct signature
  69  *      0: incorrect signature
  70  *     -1: error
  71  */
  72 int
  73 ECDSA_do_verify(const unsigned char *dgst, int dgst_len, const ECDSA_SIG *sig,
  74     EC_KEY *eckey)
  75 {
  76         ECDSA_DATA *ecdsa = ecdsa_check(eckey);
  77
  78         if (ecdsa == NULL)
  79                 return 0;
  80         return ecdsa->meth->ecdsa_do_verify(dgst, dgst_len, sig, eckey);
  81 }
  82
  83 /* returns
  84  *      1: correct signature
  85  *      0: incorrect signature
  86  *     -1: error
  87  */
  88 int
  89 ECDSA_verify(int type, const unsigned char *dgst, int dgst_len,
  90     const unsigned char *sigbuf, int sig_len, EC_KEY *eckey)
  91 {
  92         ECDSA_SIG *s;
  93         unsigned char *der = NULL;
  94         const unsigned char *p = sigbuf;
  95         int derlen = -1;
  96         int ret = -1;
  97
  98         s = ECDSA_SIG_new();
  99         if (s == NULL)
 100                 return (ret);
 101         if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL)
 102                 goto err;
 103         /* Ensure signature uses DER and doesn't have trailing garbage */
 104         derlen = i2d_ECDSA_SIG(s, &der);
 105         if (derlen != sig_len || memcmp(sigbuf, der, derlen))
 106                 goto err;
 107         ret = ECDSA_do_verify(dgst, dgst_len, s, eckey);
 108
 109 err:
 110         if (derlen > 0) {
 111                 explicit_bzero(der, derlen);
 112                 free(der);
 113         }
 114         ECDSA_SIG_free(s);
 115         return (ret);
 116 }