s2_enc.c revision 110007
1/* ssl/s2_enc.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@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@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@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@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#include "cryptlib.h"
63
64int ssl2_enc_init(SSL *s, int client)
65	{
66	/* Max number of bytes needed */
67	EVP_CIPHER_CTX *rs,*ws;
68	const EVP_CIPHER *c;
69	const EVP_MD *md;
70	int num;
71
72	if (!ssl_cipher_get_evp(s->session,&c,&md,NULL))
73		{
74		ssl2_return_error(s,SSL2_PE_NO_CIPHER);
75		SSLerr(SSL_F_SSL2_ENC_INIT,SSL_R_PROBLEMS_MAPPING_CIPHER_FUNCTIONS);
76		return(0);
77		}
78
79	s->read_hash=md;
80	s->write_hash=md;
81
82	if ((s->enc_read_ctx == NULL) &&
83		((s->enc_read_ctx=(EVP_CIPHER_CTX *)
84		OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
85		goto err;
86	if ((s->enc_write_ctx == NULL) &&
87		((s->enc_write_ctx=(EVP_CIPHER_CTX *)
88		OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
89		goto err;
90
91	rs= s->enc_read_ctx;
92	ws= s->enc_write_ctx;
93
94	EVP_CIPHER_CTX_init(rs);
95	EVP_CIPHER_CTX_init(ws);
96
97	num=c->key_len;
98	s->s2->key_material_length=num*2;
99	OPENSSL_assert(s->s2->key_material_length <= sizeof s->s2->key_material);
100
101	if (ssl2_generate_key_material(s) <= 0)
102		return 0;
103
104	OPENSSL_assert(c->iv_len <= sizeof s->session->key_arg);
105	EVP_EncryptInit_ex(ws,c,NULL,&(s->s2->key_material[(client)?num:0]),
106		s->session->key_arg);
107	EVP_DecryptInit_ex(rs,c,NULL,&(s->s2->key_material[(client)?0:num]),
108		s->session->key_arg);
109	s->s2->read_key=  &(s->s2->key_material[(client)?0:num]);
110	s->s2->write_key= &(s->s2->key_material[(client)?num:0]);
111	return(1);
112err:
113	SSLerr(SSL_F_SSL2_ENC_INIT,ERR_R_MALLOC_FAILURE);
114	return(0);
115	}
116
117/* read/writes from s->s2->mac_data using length for encrypt and
118 * decrypt.  It sets s->s2->padding and s->[rw]length
119 * if we are encrypting */
120void ssl2_enc(SSL *s, int send)
121	{
122	EVP_CIPHER_CTX *ds;
123	unsigned long l;
124	int bs;
125
126	if (send)
127		{
128		ds=s->enc_write_ctx;
129		l=s->s2->wlength;
130		}
131	else
132		{
133		ds=s->enc_read_ctx;
134		l=s->s2->rlength;
135		}
136
137	/* check for NULL cipher */
138	if (ds == NULL) return;
139
140
141	bs=ds->cipher->block_size;
142	/* This should be using (bs-1) and bs instead of 7 and 8, but
143	 * what the hell. */
144	if (bs == 8)
145		l=(l+7)/8*8;
146
147	EVP_Cipher(ds,s->s2->mac_data,s->s2->mac_data,l);
148	}
149
150void ssl2_mac(SSL *s, unsigned char *md, int send)
151	{
152	EVP_MD_CTX c;
153	unsigned char sequence[4],*p,*sec,*act;
154	unsigned long seq;
155	unsigned int len;
156
157	if (send)
158		{
159		seq=s->s2->write_sequence;
160		sec=s->s2->write_key;
161		len=s->s2->wact_data_length;
162		act=s->s2->wact_data;
163		}
164	else
165		{
166		seq=s->s2->read_sequence;
167		sec=s->s2->read_key;
168		len=s->s2->ract_data_length;
169		act=s->s2->ract_data;
170		}
171
172	p= &(sequence[0]);
173	l2n(seq,p);
174
175	/* There has to be a MAC algorithm. */
176	EVP_MD_CTX_init(&c);
177	EVP_DigestInit_ex(&c, s->read_hash, NULL);
178	EVP_DigestUpdate(&c,sec,
179		EVP_CIPHER_CTX_key_length(s->enc_read_ctx));
180	EVP_DigestUpdate(&c,act,len);
181	/* the above line also does the pad data */
182	EVP_DigestUpdate(&c,sequence,4);
183	EVP_DigestFinal_ex(&c,md,NULL);
184	EVP_MD_CTX_cleanup(&c);
185	}
186#else /* !OPENSSL_NO_SSL2 */
187
188# if PEDANTIC
189static void *dummy=&dummy;
190# endif
191
192#endif
193