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      1 /* ssl/s2_enc.c */
      2 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      3  * All rights reserved.
      4  *
      5  * This package is an SSL implementation written
      6  * by Eric Young (eay (at) cryptsoft.com).
      7  * The implementation was written so as to conform with Netscapes SSL.
      8  *
      9  * This library is free for commercial and non-commercial use as long as
     10  * the following conditions are aheared to.  The following conditions
     11  * apply to all code found in this distribution, be it the RC4, RSA,
     12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
     13  * included with this distribution is covered by the same copyright terms
     14  * except that the holder is Tim Hudson (tjh (at) cryptsoft.com).
     15  *
     16  * Copyright remains Eric Young's, and as such any Copyright notices in
     17  * the code are not to be removed.
     18  * If this package is used in a product, Eric Young should be given attribution
     19  * as the author of the parts of the library used.
     20  * This can be in the form of a textual message at program startup or
     21  * in documentation (online or textual) provided with the package.
     22  *
     23  * Redistribution and use in source and binary forms, with or without
     24  * modification, are permitted provided that the following conditions
     25  * are met:
     26  * 1. Redistributions of source code must retain the copyright
     27  *    notice, this list of conditions and the following disclaimer.
     28  * 2. Redistributions in binary form must reproduce the above copyright
     29  *    notice, this list of conditions and the following disclaimer in the
     30  *    documentation and/or other materials provided with the distribution.
     31  * 3. All advertising materials mentioning features or use of this software
     32  *    must display the following acknowledgement:
     33  *    "This product includes cryptographic software written by
     34  *     Eric Young (eay (at) cryptsoft.com)"
     35  *    The word 'cryptographic' can be left out if the rouines from the library
     36  *    being used are not cryptographic related :-).
     37  * 4. If you include any Windows specific code (or a derivative thereof) from
     38  *    the apps directory (application code) you must include an acknowledgement:
     39  *    "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)"
     40  *
     41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
     42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     51  * SUCH DAMAGE.
     52  *
     53  * The licence and distribution terms for any publically available version or
     54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
     55  * copied and put under another distribution licence
     56  * [including the GNU Public Licence.]
     57  */
     58 
     59 #include "ssl_locl.h"
     60 #ifndef OPENSSL_NO_SSL2
     61 #include <stdio.h>
     62 
     63 int ssl2_enc_init(SSL *s, int client)
     64 	{
     65 	/* Max number of bytes needed */
     66 	EVP_CIPHER_CTX *rs,*ws;
     67 	const EVP_CIPHER *c;
     68 	const EVP_MD *md;
     69 	int num;
     70 
     71 	if (!ssl_cipher_get_evp(s->session,&c,&md,NULL,NULL,NULL))
     72 		{
     73 		ssl2_return_error(s,SSL2_PE_NO_CIPHER);
     74 		SSLerr(SSL_F_SSL2_ENC_INIT,SSL_R_PROBLEMS_MAPPING_CIPHER_FUNCTIONS);
     75 		return(0);
     76 		}
     77 	ssl_replace_hash(&s->read_hash,md);
     78 	ssl_replace_hash(&s->write_hash,md);
     79 
     80 	if ((s->enc_read_ctx == NULL) &&
     81 		((s->enc_read_ctx=(EVP_CIPHER_CTX *)
     82 		OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
     83 		goto err;
     84 
     85 	/* make sure it's intialized in case the malloc for enc_write_ctx fails
     86 	 * and we exit with an error */
     87 	rs= s->enc_read_ctx;
     88 	EVP_CIPHER_CTX_init(rs);
     89 
     90 	if ((s->enc_write_ctx == NULL) &&
     91 		((s->enc_write_ctx=(EVP_CIPHER_CTX *)
     92 		OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
     93 		goto err;
     94 
     95 	ws= s->enc_write_ctx;
     96 	EVP_CIPHER_CTX_init(ws);
     97 
     98 	num=c->key_len;
     99 	s->s2->key_material_length=num*2;
    100 	OPENSSL_assert(s->s2->key_material_length <= sizeof s->s2->key_material);
    101 
    102 	if (ssl2_generate_key_material(s) <= 0)
    103 		return 0;
    104 
    105 	OPENSSL_assert(c->iv_len <= (int)sizeof(s->session->key_arg));
    106 	EVP_EncryptInit_ex(ws,c,NULL,&(s->s2->key_material[(client)?num:0]),
    107 		s->session->key_arg);
    108 	EVP_DecryptInit_ex(rs,c,NULL,&(s->s2->key_material[(client)?0:num]),
    109 		s->session->key_arg);
    110 	s->s2->read_key=  &(s->s2->key_material[(client)?0:num]);
    111 	s->s2->write_key= &(s->s2->key_material[(client)?num:0]);
    112 	return(1);
    113 err:
    114 	SSLerr(SSL_F_SSL2_ENC_INIT,ERR_R_MALLOC_FAILURE);
    115 	return(0);
    116 	}
    117 
    118 /* read/writes from s->s2->mac_data using length for encrypt and
    119  * decrypt.  It sets s->s2->padding and s->[rw]length
    120  * if we are encrypting */
    121 void ssl2_enc(SSL *s, int send)
    122 	{
    123 	EVP_CIPHER_CTX *ds;
    124 	unsigned long l;
    125 	int bs;
    126 
    127 	if (send)
    128 		{
    129 		ds=s->enc_write_ctx;
    130 		l=s->s2->wlength;
    131 		}
    132 	else
    133 		{
    134 		ds=s->enc_read_ctx;
    135 		l=s->s2->rlength;
    136 		}
    137 
    138 	/* check for NULL cipher */
    139 	if (ds == NULL) return;
    140 
    141 
    142 	bs=ds->cipher->block_size;
    143 	/* This should be using (bs-1) and bs instead of 7 and 8, but
    144 	 * what the hell. */
    145 	if (bs == 8)
    146 		l=(l+7)/8*8;
    147 
    148 	EVP_Cipher(ds,s->s2->mac_data,s->s2->mac_data,l);
    149 	}
    150 
    151 void ssl2_mac(SSL *s, unsigned char *md, int send)
    152 	{
    153 	EVP_MD_CTX c;
    154 	unsigned char sequence[4],*p,*sec,*act;
    155 	unsigned long seq;
    156 	unsigned int len;
    157 
    158 	if (send)
    159 		{
    160 		seq=s->s2->write_sequence;
    161 		sec=s->s2->write_key;
    162 		len=s->s2->wact_data_length;
    163 		act=s->s2->wact_data;
    164 		}
    165 	else
    166 		{
    167 		seq=s->s2->read_sequence;
    168 		sec=s->s2->read_key;
    169 		len=s->s2->ract_data_length;
    170 		act=s->s2->ract_data;
    171 		}
    172 
    173 	p= &(sequence[0]);
    174 	l2n(seq,p);
    175 
    176 	/* There has to be a MAC algorithm. */
    177 	EVP_MD_CTX_init(&c);
    178 	EVP_MD_CTX_copy(&c, s->read_hash);
    179 	EVP_DigestUpdate(&c,sec,
    180 		EVP_CIPHER_CTX_key_length(s->enc_read_ctx));
    181 	EVP_DigestUpdate(&c,act,len);
    182 	/* the above line also does the pad data */
    183 	EVP_DigestUpdate(&c,sequence,4);
    184 	EVP_DigestFinal_ex(&c,md,NULL);
    185 	EVP_MD_CTX_cleanup(&c);
    186 	}
    187 #else /* !OPENSSL_NO_SSL2 */
    188 
    189 # if PEDANTIC
    190 static void *dummy=&dummy;
    191 # endif
    192 
    193 #endif
    194