s2_enc.c revision 55715 
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 <stdio.h>
60#include "ssl_locl.h"
61
62int ssl2_enc_init(SSL *s, int client)
63	{
64	/* Max number of bytes needed */
65	EVP_CIPHER_CTX *rs,*ws;
66	const EVP_CIPHER *c;
67	const EVP_MD *md;
68	int num;
69
70	if (!ssl_cipher_get_evp(s->session,&c,&md,NULL))
71		{
72		ssl2_return_error(s,SSL2_PE_NO_CIPHER);
73		SSLerr(SSL_F_SSL2_ENC_INIT,SSL_R_PROBLEMS_MAPPING_CIPHER_FUNCTIONS);
74		return(0);
75		}
76
77	s->read_hash=md;
78	s->write_hash=md;
79
80	if ((s->enc_read_ctx == NULL) &&
81		((s->enc_read_ctx=(EVP_CIPHER_CTX *)
82		Malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
83		goto err;
84	if ((s->enc_write_ctx == NULL) &&
85		((s->enc_write_ctx=(EVP_CIPHER_CTX *)
86		Malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
87		goto err;
88
89	rs= s->enc_read_ctx;
90	ws= s->enc_write_ctx;
91
92	EVP_CIPHER_CTX_init(rs);
93	EVP_CIPHER_CTX_init(ws);
94
95	num=c->key_len;
96	s->s2->key_material_length=num*2;
97
98	ssl2_generate_key_material(s);
99
100	EVP_EncryptInit(ws,c,&(s->s2->key_material[(client)?num:0]),
101		s->session->key_arg);
102	EVP_DecryptInit(rs,c,&(s->s2->key_material[(client)?0:num]),
103		s->session->key_arg);
104	s->s2->read_key=  &(s->s2->key_material[(client)?0:num]);
105	s->s2->write_key= &(s->s2->key_material[(client)?num:0]);
106	return(1);
107err:
108	SSLerr(SSL_F_SSL2_ENC_INIT,ERR_R_MALLOC_FAILURE);
109	return(0);
110	}
111
112/* read/writes from s->s2->mac_data using length for encrypt and
113 * decrypt.  It sets the s->s2->padding, s->[rw]length and
114 * s->s2->pad_data ptr if we are encrypting */
115void ssl2_enc(SSL *s, int send)
116	{
117	EVP_CIPHER_CTX *ds;
118	unsigned long l;
119	int bs;
120
121	if (send)
122		{
123		ds=s->enc_write_ctx;
124		l=s->s2->wlength;
125		}
126	else
127		{
128		ds=s->enc_read_ctx;
129		l=s->s2->rlength;
130		}
131
132	/* check for NULL cipher */
133	if (ds == NULL) return;
134
135
136	bs=ds->cipher->block_size;
137	/* This should be using (bs-1) and bs instead of 7 and 8, but
138	 * what the hell. */
139	if (bs == 8)
140		l=(l+7)/8*8;
141
142	EVP_Cipher(ds,s->s2->mac_data,s->s2->mac_data,l);
143	}
144
145void ssl2_mac(SSL *s, unsigned char *md, int send)
146	{
147	EVP_MD_CTX c;
148	unsigned char sequence[4],*p,*sec,*act;
149	unsigned long seq;
150	unsigned int len;
151
152	if (send)
153		{
154		seq=s->s2->write_sequence;
155		sec=s->s2->write_key;
156		len=s->s2->wact_data_length;
157		act=s->s2->wact_data;
158		}
159	else
160		{
161		seq=s->s2->read_sequence;
162		sec=s->s2->read_key;
163		len=s->s2->ract_data_length;
164		act=s->s2->ract_data;
165		}
166
167	p= &(sequence[0]);
168	l2n(seq,p);
169
170	/* There has to be a MAC algorithm. */
171	EVP_DigestInit(&c,s->read_hash);
172	EVP_DigestUpdate(&c,sec,
173		EVP_CIPHER_CTX_key_length(s->enc_read_ctx));
174	EVP_DigestUpdate(&c,act,len);
175	/* the above line also does the pad data */
176	EVP_DigestUpdate(&c,sequence,4);
177	EVP_DigestFinal(&c,md,NULL);
178	/* some would say I should zero the md context */
179	}
180
181