1 /* ssl/d1_enc.c */
2 /*
3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
5 */
6 /* ====================================================================
7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
19 * distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * openssl-core@openssl.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 * acknowledgment:
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60 * All rights reserved.
61 *
62 * This package is an SSL implementation written
63 * by Eric Young (eay@cryptsoft.com).
64 * The implementation was written so as to conform with Netscapes SSL.
65 *
66 * This library is free for commercial and non-commercial use as long as
67 * the following conditions are aheared to. The following conditions
68 * apply to all code found in this distribution, be it the RC4, RSA,
69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
70 * included with this distribution is covered by the same copyright terms
71 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
72 *
73 * Copyright remains Eric Young's, and as such any Copyright notices in
74 * the code are not to be removed.
75 * If this package is used in a product, Eric Young should be given attribution
76 * as the author of the parts of the library used.
77 * This can be in the form of a textual message at program startup or
78 * in documentation (online or textual) provided with the package.
79 *
80 * Redistribution and use in source and binary forms, with or without
81 * modification, are permitted provided that the following conditions
82 * are met:
83 * 1. Redistributions of source code must retain the copyright
84 * notice, this list of conditions and the following disclaimer.
85 * 2. Redistributions in binary form must reproduce the above copyright
86 * notice, this list of conditions and the following disclaimer in the
87 * documentation and/or other materials provided with the distribution.
88 * 3. All advertising materials mentioning features or use of this software
89 * must display the following acknowledgement:
90 * "This product includes cryptographic software written by
91 * Eric Young (eay@cryptsoft.com)"
92 * The word 'cryptographic' can be left out if the rouines from the library
93 * being used are not cryptographic related :-).
94 * 4. If you include any Windows specific code (or a derivative thereof) from
95 * the apps directory (application code) you must include an acknowledgement:
96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
97 *
98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
108 * SUCH DAMAGE.
109 *
110 * The licence and distribution terms for any publically available version or
111 * derivative of this code cannot be changed. i.e. this code cannot simply be
112 * copied and put under another distribution licence
113 * [including the GNU Public Licence.]
114 */
115
116 #include <stdio.h>
117 #include "ssl_locl.h"
118 #include <openssl/comp.h>
119 #include <openssl/evp.h>
120 #include <openssl/hmac.h>
121 #include <openssl/md5.h>
122 #include <openssl/rand.h>
123
124
dtls1_enc(SSL * s,int send)125 int dtls1_enc(SSL *s, int send)
126 {
127 SSL3_RECORD *rec;
128 EVP_CIPHER_CTX *ds;
129 unsigned long l;
130 int bs,i,ii,j,k,n=0;
131 const EVP_CIPHER *enc;
132
133 if (send)
134 {
135 if (s->write_hash != NULL)
136 n=EVP_MD_size(s->write_hash);
137 ds=s->enc_write_ctx;
138 rec= &(s->s3->wrec);
139 if (s->enc_write_ctx == NULL)
140 enc=NULL;
141 else
142 {
143 enc=EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
144 if ( rec->data != rec->input)
145 /* we can't write into the input stream */
146 fprintf(stderr, "%s:%d: rec->data != rec->input\n",
147 __FILE__, __LINE__);
148 else if ( EVP_CIPHER_block_size(ds->cipher) > 1)
149 {
150 if (!RAND_bytes(rec->input, EVP_CIPHER_block_size(ds->cipher)))
151 return -1;
152 }
153 }
154 }
155 else
156 {
157 if (s->read_hash != NULL)
158 n=EVP_MD_size(s->read_hash);
159 ds=s->enc_read_ctx;
160 rec= &(s->s3->rrec);
161 if (s->enc_read_ctx == NULL)
162 enc=NULL;
163 else
164 enc=EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
165 }
166
167 #ifdef KSSL_DEBUG
168 printf("dtls1_enc(%d)\n", send);
169 #endif /* KSSL_DEBUG */
170
171 if ((s->session == NULL) || (ds == NULL) ||
172 (enc == NULL))
173 {
174 memmove(rec->data,rec->input,rec->length);
175 rec->input=rec->data;
176 }
177 else
178 {
179 l=rec->length;
180 bs=EVP_CIPHER_block_size(ds->cipher);
181
182 if ((bs != 1) && send)
183 {
184 i=bs-((int)l%bs);
185
186 /* Add weird padding of upto 256 bytes */
187
188 /* we need to add 'i' padding bytes of value j */
189 j=i-1;
190 if (s->options & SSL_OP_TLS_BLOCK_PADDING_BUG)
191 {
192 if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG)
193 j++;
194 }
195 for (k=(int)l; k<(int)(l+i); k++)
196 rec->input[k]=j;
197 l+=i;
198 rec->length+=i;
199 }
200
201 #ifdef KSSL_DEBUG
202 {
203 unsigned long ui;
204 printf("EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n",
205 ds,rec->data,rec->input,l);
206 printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%d %d], %d iv_len\n",
207 ds->buf_len, ds->cipher->key_len,
208 DES_KEY_SZ, DES_SCHEDULE_SZ,
209 ds->cipher->iv_len);
210 printf("\t\tIV: ");
211 for (i=0; i<ds->cipher->iv_len; i++) printf("%02X", ds->iv[i]);
212 printf("\n");
213 printf("\trec->input=");
214 for (ui=0; ui<l; ui++) printf(" %02x", rec->input[ui]);
215 printf("\n");
216 }
217 #endif /* KSSL_DEBUG */
218
219 if (!send)
220 {
221 if (l == 0 || l%bs != 0)
222 {
223 SSLerr(SSL_F_DTLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
224 ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED);
225 return 0;
226 }
227 }
228
229 EVP_Cipher(ds,rec->data,rec->input,l);
230
231 #ifdef KSSL_DEBUG
232 {
233 unsigned long i;
234 printf("\trec->data=");
235 for (i=0; i<l; i++)
236 printf(" %02x", rec->data[i]); printf("\n");
237 }
238 #endif /* KSSL_DEBUG */
239
240 if ((bs != 1) && !send)
241 {
242 ii=i=rec->data[l-1]; /* padding_length */
243 i++;
244 if (s->options&SSL_OP_TLS_BLOCK_PADDING_BUG)
245 {
246 /* First packet is even in size, so check */
247 if ((memcmp(s->s3->read_sequence,
248 "\0\0\0\0\0\0\0\0",8) == 0) && !(ii & 1))
249 s->s3->flags|=TLS1_FLAGS_TLS_PADDING_BUG;
250 if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG)
251 i--;
252 }
253 /* TLS 1.0 does not bound the number of padding bytes by the block size.
254 * All of them must have value 'padding_length'. */
255 if (i > (int)rec->length)
256 {
257 /* Incorrect padding. SSLerr() and ssl3_alert are done
258 * by caller: we don't want to reveal whether this is
259 * a decryption error or a MAC verification failure
260 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
261 */
262 return -1;
263 }
264 for (j=(int)(l-i); j<(int)l; j++)
265 {
266 if (rec->data[j] != ii)
267 {
268 /* Incorrect padding */
269 return -1;
270 }
271 }
272 rec->length-=i;
273
274 rec->data += bs; /* skip the implicit IV */
275 rec->input += bs;
276 rec->length -= bs;
277 }
278 }
279 return(1);
280 }
281
282