openssl1.0/ssl/s2_enc.c

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2019-08-09 10:00:55 +02:00
/* 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, NULL, NULL)) {
ssl2_return_error(s, SSL2_PE_NO_CIPHER);
SSLerr(SSL_F_SSL2_ENC_INIT, SSL_R_PROBLEMS_MAPPING_CIPHER_FUNCTIONS);
return (0);
}
ssl_replace_hash(&s->read_hash, md);
ssl_replace_hash(&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 Returns 0 on
* error and 1 on success
*/
int 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 1;
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;
if (EVP_Cipher(ds, s->s2->mac_data, s->s2->mac_data, l) < 1)
return 0;
return 1;
}
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_MD_CTX_copy(&c, s->read_hash);
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