/* ssl/s2_enc.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.]

 */

#include "ssl_locl.h"

#ifndef OPENSSL_NO_SSL2

#include <stdio.h>

int ssl2_enc_init(SSL *s, int client)

	{

	/* Max number of bytes needed */

	EVP_CIPHER_CTX *rs,*ws;

	const EVP_CIPHER *c;

	const EVP_MD *md;

	int num;

	if (!ssl_cipher_get_evp(s->session,&c,&md,NULL))

		{

		ssl2_return_error(s,SSL2_PE_NO_CIPHER);

		SSLerr(SSL_F_SSL2_ENC_INIT,SSL_R_PROBLEMS_MAPPING_CIPHER_FUNCTIONS);

		return(0);

		}

	s->read_hash=md;

	s->write_hash=md;

	if ((s->enc_read_ctx == NULL) &&

		((s->enc_read_ctx=(EVP_CIPHER_CTX *)

		OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL))

		goto err;

	/* make sure it's intialized in case the malloc for enc_write_ctx fails

	 * and we exit with an error */

	rs= s->enc_read_ctx;

	EVP_CIPHER_CTX_init(rs);

	if ((s->enc_write_ctx == NULL) &&

		((s->enc_write_ctx=(EVP_CIPHER_CTX *)

		OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL))

		goto err;

	ws= s->enc_write_ctx;

	EVP_CIPHER_CTX_init(ws);

	num=c->key_len;

	s->s2->key_material_length=num*2;

	OPENSSL_assert(s->s2->key_material_length <= sizeof s->s2->key_material);

	if (ssl2_generate_key_material(s) <= 0)

		return 0;

	OPENSSL_assert(c->iv_len <= (int)sizeof(s->session->key_arg));

	EVP_EncryptInit_ex(ws,c,NULL,&(s->s2->key_material[(client)?num:0]),

		s->session->key_arg);

	EVP_DecryptInit_ex(rs,c,NULL,&(s->s2->key_material[(client)?0:num]),

		s->session->key_arg);

	s->s2->read_key=  &(s->s2->key_material[(client)?0:num]);

	s->s2->write_key= &(s->s2->key_material[(client)?num:0]);

	return(1);

err:

	SSLerr(SSL_F_SSL2_ENC_INIT,ERR_R_MALLOC_FAILURE);

	return(0);

	}

/* read/writes from s->s2->mac_data using length for encrypt and 

 * decrypt.  It sets s->s2->padding and s->[rw]length

 * if we are encrypting */

void ssl2_enc(SSL *s, int send)

	{

	EVP_CIPHER_CTX *ds;

	unsigned long l;

	int bs;

	if (send)

		{

		ds=s->enc_write_ctx;

		l=s->s2->wlength;

		}

	else

		{

		ds=s->enc_read_ctx;

		l=s->s2->rlength;

		}

	/* check for NULL cipher */

	if (ds == NULL) return;

	bs=ds->cipher->block_size;

	/* This should be using (bs-1) and bs instead of 7 and 8, but

	 * what the hell. */

	if (bs == 8)

		l=(l+7)/8*8;

	EVP_Cipher(ds,s->s2->mac_data,s->s2->mac_data,l);

	}

void ssl2_mac(SSL *s, unsigned char *md, int send)

	{

	EVP_MD_CTX c;

	unsigned char sequence[4],*p,*sec,*act;

	unsigned long seq;

	unsigned int len;

	if (send)

		{

		seq=s->s2->write_sequence;

		sec=s->s2->write_key;

		len=s->s2->wact_data_length;

		act=s->s2->wact_data;

		}

	else

		{

		seq=s->s2->read_sequence;

		sec=s->s2->read_key;

		len=s->s2->ract_data_length;

		act=s->s2->ract_data;

		}

	p= &(sequence[0]);

	l2n(seq,p);

	/* There has to be a MAC algorithm. */

	EVP_MD_CTX_init(&c);

	EVP_DigestInit_ex(&c, s->read_hash, NULL);

	EVP_DigestUpdate(&c,sec,

		EVP_CIPHER_CTX_key_length(s->enc_read_ctx));

	EVP_DigestUpdate(&c,act,len); 

	/* the above line also does the pad data */

	EVP_DigestUpdate(&c,sequence,4); 

	EVP_DigestFinal_ex(&c,md,NULL);

	EVP_MD_CTX_cleanup(&c);

	}

#else /* !OPENSSL_NO_SSL2 */

# if PEDANTIC

static void *dummy=&dummy;

# endif

#endif