text: /* $OpenBSD: p_verify.c,v 1.11 2014/06/12 15:49:29 deraadt Exp $ */
  /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   * All rights reserved.
   *
   * This package is an SSL implementation written
   * by Eric Young (eay@cryptsoft.com).
   * The implementation was written so as to conform with Netscapes SSL.
   *
   * This library is free for commercial and non-commercial use as long as
   * the following conditions are aheared to.  The following conditions
   * apply to all code found in this distribution, be it the RC4, RSA,
   * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
   * included with this distribution is covered by the same copyright terms
   * except that the holder is Tim Hudson (tjh@cryptsoft.com).
   *
   * Copyright remains Eric Young's, and as such any Copyright notices in
   * the code are not to be removed.
   * If this package is used in a product, Eric Young should be given attribution
   * as the author of the parts of the library used.
   * This can be in the form of a textual message at program startup or
   * in documentation (online or textual) provided with the package.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *    "This product includes cryptographic software written by
   *     Eric Young (eay@cryptsoft.com)"
   *    The word 'cryptographic' can be left out if the rouines from the library
   *    being used are not cryptographic related :-).
   * 4. If you include any Windows specific code (or a derivative thereof) from
   *    the apps directory (application code) you must include an acknowledgement:
   *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
   *
   * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * The licence and distribution terms for any publically available version or
   * derivative of this code cannot be changed.  i.e. this code cannot simply be
   * copied and put under another distribution licence
   * [including the GNU Public Licence.]
   */
  
  #include <stdio.h>
  
  #include <openssl/err.h>
  #include <openssl/evp.h>
  #include <openssl/objects.h>
  #include <openssl/x509.h>
  
  int
  EVP_VerifyFinal(EVP_MD_CTX *ctx, const unsigned char *sigbuf,
      unsigned int siglen, EVP_PKEY *pkey)
  {
  	unsigned char m[EVP_MAX_MD_SIZE];
  	unsigned int m_len;
  	int i = 0, ok = 0, v;
  	EVP_MD_CTX tmp_ctx;
  	EVP_PKEY_CTX *pkctx = NULL;
  
  	EVP_MD_CTX_init(&tmp_ctx);
  	if (!EVP_MD_CTX_copy_ex(&tmp_ctx, ctx))
  		goto err;
  	if (!EVP_DigestFinal_ex(&tmp_ctx, &(m[0]), &m_len))
  		goto err;
  	EVP_MD_CTX_cleanup(&tmp_ctx);
  
  	if (ctx->digest->flags & EVP_MD_FLAG_PKEY_METHOD_SIGNATURE) {
  		i = -1;
  		pkctx = EVP_PKEY_CTX_new(pkey, NULL);
  		if (!pkctx)
  			goto err;
  		if (EVP_PKEY_verify_init(pkctx) <= 0)
  			goto err;
  		if (EVP_PKEY_CTX_set_signature_md(pkctx, ctx->digest) <= 0)
  			goto err;
  		i = EVP_PKEY_verify(pkctx, sigbuf, siglen, m, m_len);
  err:
  		EVP_PKEY_CTX_free(pkctx);
  		return i;
  	}
  
  	for (i = 0; i < 4; i++) {
  		v = ctx->digest->required_pkey_type[i];
  		if (v == 0)
  			break;
  		if (pkey->type == v) {
  			ok = 1;
  			break;
  		}
  	}
  	if (!ok) {
  		EVPerr(EVP_F_EVP_VERIFYFINAL, EVP_R_WRONG_PUBLIC_KEY_TYPE);
  		return (-1);
  	}
  	if (ctx->digest->verify == NULL) {
  		EVPerr(EVP_F_EVP_VERIFYFINAL,
  		    EVP_R_NO_VERIFY_FUNCTION_CONFIGURED);
  		return (0);
  	}
  
  	return(ctx->digest->verify(ctx->digest->type, m, m_len,
  	    sigbuf, siglen, pkey->pkey.ptr));
  }
  