s2_enc.c revision 296465 
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)) {
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) && ((s->enc_read_ctx = (EVP_CIPHER_CTX *)
81                                       OPENSSL_malloc(sizeof(EVP_CIPHER_CTX)))
82                                      == NULL))
83        goto err;
84
85    /*
86     * make sure it's intialized in case the malloc for enc_write_ctx fails
87     * and we exit with an error
88     */
89    rs = s->enc_read_ctx;
90    EVP_CIPHER_CTX_init(rs);
91
92    if ((s->enc_write_ctx == NULL) && ((s->enc_write_ctx = (EVP_CIPHER_CTX *)
93                                        OPENSSL_malloc(sizeof
94                                                       (EVP_CIPHER_CTX))) ==
95                                       NULL))
96        goto err;
97
98    ws = s->enc_write_ctx;
99    EVP_CIPHER_CTX_init(ws);
100
101    num = c->key_len;
102    s->s2->key_material_length = num * 2;
103    OPENSSL_assert(s->s2->key_material_length <= sizeof s->s2->key_material);
104
105    if (ssl2_generate_key_material(s) <= 0)
106        return 0;
107
108    OPENSSL_assert(c->iv_len <= (int)sizeof(s->session->key_arg));
109    EVP_EncryptInit_ex(ws, c, NULL,
110                       &(s->s2->key_material[(client) ? num : 0]),
111                       s->session->key_arg);
112    EVP_DecryptInit_ex(rs, c, NULL,
113                       &(s->s2->key_material[(client) ? 0 : num]),
114                       s->session->key_arg);
115    s->s2->read_key = &(s->s2->key_material[(client) ? 0 : num]);
116    s->s2->write_key = &(s->s2->key_material[(client) ? num : 0]);
117    return (1);
118 err:
119    SSLerr(SSL_F_SSL2_ENC_INIT, ERR_R_MALLOC_FAILURE);
120    return (0);
121}
122
123/*
124 * read/writes from s->s2->mac_data using length for encrypt and decrypt.
125 * It sets s->s2->padding and s->[rw]length if we are encrypting
126 */
127void 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;
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    EVP_Cipher(ds, s->s2->mac_data, s->s2->mac_data, l);
154}
155
156void ssl2_mac(SSL *s, unsigned char *md, int send)
157{
158    EVP_MD_CTX c;
159    unsigned char sequence[4], *p, *sec, *act;
160    unsigned long seq;
161    unsigned int len;
162
163    if (send) {
164        seq = s->s2->write_sequence;
165        sec = s->s2->write_key;
166        len = s->s2->wact_data_length;
167        act = s->s2->wact_data;
168    } else {
169        seq = s->s2->read_sequence;
170        sec = s->s2->read_key;
171        len = s->s2->ract_data_length;
172        act = s->s2->ract_data;
173    }
174
175    p = &(sequence[0]);
176    l2n(seq, p);
177
178    /* There has to be a MAC algorithm. */
179    EVP_MD_CTX_init(&c);
180    EVP_DigestInit_ex(&c, s->read_hash, NULL);
181    EVP_DigestUpdate(&c, sec, EVP_CIPHER_CTX_key_length(s->enc_read_ctx));
182    EVP_DigestUpdate(&c, act, len);
183    /* the above line also does the pad data */
184    EVP_DigestUpdate(&c, sequence, 4);
185    EVP_DigestFinal_ex(&c, md, NULL);
186    EVP_MD_CTX_cleanup(&c);
187}
188#else                           /* !OPENSSL_NO_SSL2 */
189
190# if PEDANTIC
191static void *dummy = &dummy;
192# endif
193
194#endif
195