evp_lib.c

mediastreamer2是开源的网络传输媒体流的库

/* crypto/evp/evp_lib.c */
/* Copyright (C) 1995-1998 Eric Young ([e-mail])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([e-mail]).
 * 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 ([e-mail]).
 * 
 * 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 ([e-mail])"
 *    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 ([e-mail])"
 * 
 * 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 "cryptlib.h"
#include <openssl/evp.h>
#include <openssl/objects.h>

int EVP_CIPHER_param_to_asn1(EVP_CIPHER_CTX *c, ASN1_TYPE *type)
	{
	int ret;

	if (c->cipher->set_asn1_parameters != NULL)
		ret=c->cipher->set_asn1_parameters(c,type);
	else
		ret=-1;
	return(ret);
	}

int EVP_CIPHER_asn1_to_param(EVP_CIPHER_CTX *c, ASN1_TYPE *type)
	{
	int ret;

	if (c->cipher->get_asn1_parameters != NULL)
		ret=c->cipher->get_asn1_parameters(c,type);
	else
		ret=-1;
	return(ret);
	}

int EVP_CIPHER_get_asn1_iv(EVP_CIPHER_CTX *c, ASN1_TYPE *type)
	{
	int i=0;
	unsigned int l;

	if (type != NULL) 
		{
		l=EVP_CIPHER_CTX_iv_length(c);
		OPENSSL_assert(l <= sizeof(c->iv));
		i=ASN1_TYPE_get_octetstring(type,c->oiv,l);
		if (i != (int)l)
			return(-1);
		else if (i > 0)
			memcpy(c->iv,c->oiv,l);
		}
	return(i);
	}

int EVP_CIPHER_set_asn1_iv(EVP_CIPHER_CTX *c, ASN1_TYPE *type)
	{
	int i=0;
	unsigned int j;

	if (type != NULL)
		{
		j=EVP_CIPHER_CTX_iv_length(c);
		OPENSSL_assert(j <= sizeof(c->iv));
		i=ASN1_TYPE_set_octetstring(type,c->oiv,j);
		}
	return(i);
	}

/* Convert the various cipher NIDs and dummies to a proper OID NID */
int EVP_CIPHER_type(const EVP_CIPHER *ctx)
{
	int nid;
	ASN1_OBJECT *otmp;
	nid = EVP_CIPHER_nid(ctx);

	switch(nid) {

		case NID_rc2_cbc:
		case NID_rc2_64_cbc:
		case NID_rc2_40_cbc:

		return NID_rc2_cbc;

		case NID_rc4:
		case NID_rc4_40:

		return NID_rc4;

		case NID_aes_128_cfb128:
		case NID_aes_128_cfb8:
		case NID_aes_128_cfb1:

		return NID_aes_128_cfb128;

		case NID_aes_192_cfb128:
		case NID_aes_192_cfb8:
		case NID_aes_192_cfb1:

		return NID_aes_192_cfb128;

		case NID_aes_256_cfb128:
		case NID_aes_256_cfb8:
		case NID_aes_256_cfb1:

		return NID_aes_256_cfb128;

		case NID_des_cfb64:
		case NID_des_cfb8:
		case NID_des_cfb1:

		return NID_des_cfb64;

		default:
		/* Check it has an OID and it is valid */
		otmp = OBJ_nid2obj(nid);
		if(!otmp || !otmp->data) nid = NID_undef;
		ASN1_OBJECT_free(otmp);
		return nid;
	}
}