text: /* crypto/evp/digest.c */
  /* 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.]
   */
  /* ====================================================================
   * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
   *
   * 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 above 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 acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
   *
   * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
   *    endorse or promote products derived from this software without
   *    prior written permission. For written permission, please contact
   *    openssl-core@openssl.org.
   *
   * 5. Products derived from this software may not be called "OpenSSL"
   *    nor may "OpenSSL" appear in their names without prior written
   *    permission of the OpenSSL Project.
   *
   * 6. Redistributions of any form whatsoever must retain the following
   *    acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
   *
   * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
   * EXPRESSED 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 OpenSSL PROJECT OR
   * ITS 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.
   * ====================================================================
   *
   * This product includes cryptographic software written by Eric Young
   * (eay@cryptsoft.com).  This product includes software written by Tim
   * Hudson (tjh@cryptsoft.com).
   *
   */
  
  #include <stdio.h>
  #include "cryptlib.h"
  #include <openssl/objects.h>
  #include <openssl/evp.h>
  #ifndef OPENSSL_NO_ENGINE
  #include <openssl/engine.h>
  #endif
  
  void EVP_MD_CTX_init(EVP_MD_CTX *ctx)
  	{
  	memset(ctx,'\0',sizeof *ctx);
  	}
  
  EVP_MD_CTX *EVP_MD_CTX_create(void)
  	{
  	EVP_MD_CTX *ctx=OPENSSL_malloc(sizeof *ctx);
  
  	EVP_MD_CTX_init(ctx);
  
  	return ctx;
  	}
  
  int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type)
  	{
  	EVP_MD_CTX_init(ctx);
  	return EVP_DigestInit_ex(ctx, type, NULL);
  	}
  
  int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl)
  	{
  	EVP_MD_CTX_clear_flags(ctx,EVP_MD_CTX_FLAG_CLEANED);
  #ifndef OPENSSL_NO_ENGINE
  	/* Whether it's nice or not, "Inits" can be used on "Final"'d contexts
  	 * so this context may already have an ENGINE! Try to avoid releasing
  	 * the previous handle, re-querying for an ENGINE, and having a
  	 * reinitialisation, when it may all be unecessary. */
  	if (ctx->engine && ctx->digest && (!type ||
  			(type && (type->type == ctx->digest->type))))
  		goto skip_to_init;
  	if (type)
  		{
  		/* Ensure an ENGINE left lying around from last time is cleared
  		 * (the previous check attempted to avoid this if the same
  		 * ENGINE and EVP_MD could be used). */
  		if(ctx->engine)
  			ENGINE_finish(ctx->engine);
  		if(impl)
  			{
  			if (!ENGINE_init(impl))
  				{
  				EVPerr(EVP_F_EVP_DIGESTINIT, EVP_R_INITIALIZATION_ERROR);
  				return 0;
  				}
  			}
  		else
  			/* Ask if an ENGINE is reserved for this job */
  			impl = ENGINE_get_digest_engine(type->type);
  		if(impl)
  			{
  			/* There's an ENGINE for this job ... (apparently) */
  			const EVP_MD *d = ENGINE_get_digest(impl, type->type);
  			if(!d)
  				{
  				/* Same comment from evp_enc.c */
  				EVPerr(EVP_F_EVP_DIGESTINIT, EVP_R_INITIALIZATION_ERROR);
  				return 0;
  				}
  			/* We'll use the ENGINE's private digest definition */
  			type = d;
  			/* Store the ENGINE functional reference so we know
  			 * 'type' came from an ENGINE and we need to release
  			 * it when done. */
  			ctx->engine = impl;
  			}
  		else
  			ctx->engine = NULL;
  		}
  	else
  	if(!ctx->digest)
  		{
  		EVPerr(EVP_F_EVP_DIGESTINIT, EVP_R_NO_DIGEST_SET);
  		return 0;
  		}
  #endif
  	if (ctx->digest != type)
  		{
  		if (ctx->digest && ctx->digest->ctx_size)
  			OPENSSL_free(ctx->md_data);
  		ctx->digest=type;
  		if (type->ctx_size)
  			ctx->md_data=OPENSSL_malloc(type->ctx_size);
  		}
  #ifndef OPENSSL_NO_ENGINE
  skip_to_init:
  #endif
  	return ctx->digest->init(ctx);
  	}
  
  int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data,
  	     unsigned int count)
  	{
  	return ctx->digest->update(ctx,data,(unsigned long)count);
  	}
  
  /* The caller can assume that this removes any secret data from the context */
  int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *size)
  	{
  	int ret;
  	ret = EVP_DigestFinal_ex(ctx, md, size);
  	EVP_MD_CTX_cleanup(ctx);
  	return ret;
  	}
  
  /* The caller can assume that this removes any secret data from the context */
  int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *size)
  	{
  	int ret;
  
  	OPENSSL_assert(ctx->digest->md_size <= EVP_MAX_MD_SIZE);
  	ret=ctx->digest->final(ctx,md);
  	if (size != NULL)
  		*size=ctx->digest->md_size;
  	if (ctx->digest->cleanup)
  		{
  		ctx->digest->cleanup(ctx);
  		EVP_MD_CTX_set_flags(ctx,EVP_MD_CTX_FLAG_CLEANED);
  		}
  	memset(ctx->md_data,0,ctx->digest->ctx_size);
  	return ret;
  	}
  
  int EVP_MD_CTX_copy(EVP_MD_CTX *out, const EVP_MD_CTX *in)
  	{
  	EVP_MD_CTX_init(out);
  	return EVP_MD_CTX_copy_ex(out, in);
  	}
  
  int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in)
  	{
  	unsigned char *tmp_buf;
  	if ((in == NULL) || (in->digest == NULL))
  		{
  		EVPerr(EVP_F_EVP_MD_CTX_COPY,EVP_R_INPUT_NOT_INITIALIZED);
  		return 0;
  		}
  #ifndef OPENSSL_NO_ENGINE
  	/* Make sure it's safe to copy a digest context using an ENGINE */
  	if (in->engine && !ENGINE_init(in->engine))
  		{
  		EVPerr(EVP_F_EVP_MD_CTX_COPY,ERR_R_ENGINE_LIB);
  		return 0;
  		}
  #endif
  
  	if (out->digest == in->digest)
  		{
  		tmp_buf = out->md_data;
  	    	EVP_MD_CTX_set_flags(out,EVP_MD_CTX_FLAG_REUSE);
  		}
  	else tmp_buf = NULL;
  	EVP_MD_CTX_cleanup(out);
  	memcpy(out,in,sizeof *out);
  
  	if (out->digest->ctx_size)
  		{
  		if (tmp_buf) out->md_data = tmp_buf;
  		else out->md_data=OPENSSL_malloc(out->digest->ctx_size);
  		memcpy(out->md_data,in->md_data,out->digest->ctx_size);
  		}
  
  	if (out->digest->copy)
  		return out->digest->copy(out,in);
  	
  	return 1;
  	}
  
  int EVP_Digest(void *data, unsigned int count,
  		unsigned char *md, unsigned int *size, const EVP_MD *type, ENGINE *impl)
  	{
  	EVP_MD_CTX ctx;
  	int ret;
  
  	EVP_MD_CTX_init(&ctx);
  	EVP_MD_CTX_set_flags(&ctx,EVP_MD_CTX_FLAG_ONESHOT);
  	ret=EVP_DigestInit_ex(&ctx, type, impl)
  	  && EVP_DigestUpdate(&ctx, data, count)
  	  && EVP_DigestFinal_ex(&ctx, md, size);
  	EVP_MD_CTX_cleanup(&ctx);
  
  	return ret;
  	}
  
  void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx)
  	{
  	EVP_MD_CTX_cleanup(ctx);
  	OPENSSL_free(ctx);
  	}
  
  /* This call frees resources associated with the context */
  int EVP_MD_CTX_cleanup(EVP_MD_CTX *ctx)
  	{
  	/* Don't assume ctx->md_data was cleaned in EVP_Digest_Final,
  	 * because sometimes only copies of the context are ever finalised.
  	 */
  	if (ctx->digest && ctx->digest->cleanup
  	    && !EVP_MD_CTX_test_flags(ctx,EVP_MD_CTX_FLAG_CLEANED))
  		ctx->digest->cleanup(ctx);
  	if (ctx->digest && ctx->digest->ctx_size && ctx->md_data
  	    && !EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_REUSE))
  		{
  		OPENSSL_cleanse(ctx->md_data,ctx->digest->ctx_size);
  		OPENSSL_free(ctx->md_data);
  		}
  #ifndef OPENSSL_NO_ENGINE
  	if(ctx->engine)
  		/* The EVP_MD we used belongs to an ENGINE, release the
  		 * functional reference we held for this reason. */
  		ENGINE_finish(ctx->engine);
  #endif
  	memset(ctx,'\0',sizeof *ctx);
  
  	return 1;
  	}
  