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 
ssl2_enc_init(SSL * s,int client)63 int 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  */
ssl2_enc(SSL * s,int send)127 int 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 
ssl2_mac(SSL * s,unsigned char * md,int send)159 void 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
194 static void *dummy = &dummy;
195 # endif
196 
197 #endif
198