s2_enc.c revision 331638 
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
63int 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        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    ssl_replace_hash(&s->read_hash, md);
77    ssl_replace_hash(&s->write_hash, md);
78
79    if ((s->enc_read_ctx == NULL) && ((s->enc_read_ctx = (EVP_CIPHER_CTX *)
80                                       OPENSSL_malloc(sizeof(EVP_CIPHER_CTX)))
81                                      == NULL))
82        goto err;
83
84    /*
85     * make sure it's intialized in case the malloc for enc_write_ctx fails
86     * and we exit with an error
87     */
88    rs = s->enc_read_ctx;
89    EVP_CIPHER_CTX_init(rs);
90
91    if ((s->enc_write_ctx == NULL) && ((s->enc_write_ctx = (EVP_CIPHER_CTX *)
92                                        OPENSSL_malloc(sizeof
93                                                       (EVP_CIPHER_CTX))) ==
94                                       NULL))
95        goto err;
96
97    ws = s->enc_write_ctx;
98    EVP_CIPHER_CTX_init(ws);
99
100    num = c->key_len;
101    s->s2->key_material_length = num * 2;
102    OPENSSL_assert(s->s2->key_material_length <= sizeof(s->s2->key_material));
103
104    if (ssl2_generate_key_material(s) <= 0)
105        return 0;
106
107    OPENSSL_assert(c->iv_len <= (int)sizeof(s->session->key_arg));
108    EVP_EncryptInit_ex(ws, c, NULL,
109                       &(s->s2->key_material[(client) ? num : 0]),
110                       s->session->key_arg);
111    EVP_DecryptInit_ex(rs, c, NULL,
112                       &(s->s2->key_material[(client) ? 0 : num]),
113                       s->session->key_arg);
114    s->s2->read_key = &(s->s2->key_material[(client) ? 0 : num]);
115    s->s2->write_key = &(s->s2->key_material[(client) ? num : 0]);
116    return (1);
117 err:
118    SSLerr(SSL_F_SSL2_ENC_INIT, ERR_R_MALLOC_FAILURE);
119    return (0);
120}
121
122/*
123 * read/writes from s->s2->mac_data using length for encrypt and decrypt.
124 * It sets s->s2->padding and s->[rw]length if we are encrypting Returns 0 on
125 * error and 1 on success
126 */
127int ssl2_enc(SSL *s, int send)
128{
129    EVP_CIPHER_CTX *ds;
130    unsigned long l;
131    int bs;
132
133    if (send) {
134        ds = s->enc_write_ctx;
135        l = s->s2->wlength;
136    } else {
137        ds = s->enc_read_ctx;
138        l = s->s2->rlength;
139    }
140
141    /* check for NULL cipher */
142    if (ds == NULL)
143        return 1;
144
145    bs = ds->cipher->block_size;
146    /*
147     * This should be using (bs-1) and bs instead of 7 and 8, but what the
148     * hell.
149     */
150    if (bs == 8)
151        l = (l + 7) / 8 * 8;
152
153    if (EVP_Cipher(ds, s->s2->mac_data, s->s2->mac_data, l) < 1)
154        return 0;
155
156    return 1;
157}
158
159void ssl2_mac(SSL *s, unsigned char *md, int send)
160{
161    EVP_MD_CTX c;
162    unsigned char sequence[4], *p, *sec, *act;
163    unsigned long seq;
164    unsigned int len;
165
166    if (send) {
167        seq = s->s2->write_sequence;
168        sec = s->s2->write_key;
169        len = s->s2->wact_data_length;
170        act = s->s2->wact_data;
171    } else {
172        seq = s->s2->read_sequence;
173        sec = s->s2->read_key;
174        len = s->s2->ract_data_length;
175        act = s->s2->ract_data;
176    }
177
178    p = &(sequence[0]);
179    l2n(seq, p);
180
181    /* There has to be a MAC algorithm. */
182    EVP_MD_CTX_init(&c);
183    EVP_MD_CTX_copy(&c, s->read_hash);
184    EVP_DigestUpdate(&c, sec, EVP_CIPHER_CTX_key_length(s->enc_read_ctx));
185    EVP_DigestUpdate(&c, act, len);
186    /* the above line also does the pad data */
187    EVP_DigestUpdate(&c, sequence, 4);
188    EVP_DigestFinal_ex(&c, md, NULL);
189    EVP_MD_CTX_cleanup(&c);
190}
191#else                           /* !OPENSSL_NO_SSL2 */
192
193# if PEDANTIC
194static void *dummy = &dummy;
195# endif
196
197#endif
198