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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 #ifndef OPENSSL_NO_COMP
119 #include <openssl/comp.h>
120 #endif
121 #include <openssl/evp.h>
122 #include <openssl/hmac.h>
123 #include <openssl/md5.h>
124 #include <openssl/rand.h>
125 #ifdef KSSL_DEBUG
126 #include <openssl/des.h>
127 #endif
128 
129 /* dtls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
130  *
131  * Returns:
132  *   0: (in non-constant time) if the record is publically invalid (i.e. too
133  *       short etc).
134  *   1: if the record's padding is valid / the encryption was successful.
135  *   -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
136  *       an internal error occured. */
dtls1_enc(SSL * s,int send)137 int dtls1_enc(SSL *s, int send)
138 	{
139 	SSL3_RECORD *rec;
140 	EVP_CIPHER_CTX *ds;
141 	unsigned long l;
142 	int bs,i,j,k,mac_size=0;
143 	const EVP_CIPHER *enc;
144 
145 	if (send)
146 		{
147 		if (EVP_MD_CTX_md(s->write_hash))
148 			{
149 			mac_size=EVP_MD_CTX_size(s->write_hash);
150 			if (mac_size < 0)
151 				return -1;
152 			}
153 		ds=s->enc_write_ctx;
154 		rec= &(s->s3->wrec);
155 		if (s->enc_write_ctx == NULL)
156 			enc=NULL;
157 		else
158 			{
159 			enc=EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
160 			if ( rec->data != rec->input)
161 				/* we can't write into the input stream */
162 				fprintf(stderr, "%s:%d: rec->data != rec->input\n",
163 					__FILE__, __LINE__);
164 			else if ( EVP_CIPHER_block_size(ds->cipher) > 1)
165 				{
166 				if (RAND_bytes(rec->input, EVP_CIPHER_block_size(ds->cipher)) <= 0)
167 					return -1;
168 				}
169 			}
170 		}
171 	else
172 		{
173 		if (EVP_MD_CTX_md(s->read_hash))
174 			{
175 			mac_size=EVP_MD_CTX_size(s->read_hash);
176 			OPENSSL_assert(mac_size >= 0);
177 			}
178 		ds=s->enc_read_ctx;
179 		rec= &(s->s3->rrec);
180 		if (s->enc_read_ctx == NULL)
181 			enc=NULL;
182 		else
183 			enc=EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
184 		}
185 
186 #ifdef KSSL_DEBUG
187 	printf("dtls1_enc(%d)\n", send);
188 #endif    /* KSSL_DEBUG */
189 
190 	if ((s->session == NULL) || (ds == NULL) ||
191 		(enc == NULL))
192 		{
193 		memmove(rec->data,rec->input,rec->length);
194 		rec->input=rec->data;
195 		}
196 	else
197 		{
198 		l=rec->length;
199 		bs=EVP_CIPHER_block_size(ds->cipher);
200 
201 		if ((bs != 1) && send)
202 			{
203 			i=bs-((int)l%bs);
204 
205 			/* Add weird padding of upto 256 bytes */
206 
207 			/* we need to add 'i' padding bytes of value j */
208 			j=i-1;
209 			if (s->options & SSL_OP_TLS_BLOCK_PADDING_BUG)
210 				{
211 				if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG)
212 					j++;
213 				}
214 			for (k=(int)l; k<(int)(l+i); k++)
215 				rec->input[k]=j;
216 			l+=i;
217 			rec->length+=i;
218 			}
219 
220 #ifdef KSSL_DEBUG
221 		{
222                 unsigned long ui;
223 		printf("EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n",
224                         ds,rec->data,rec->input,l);
225 		printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%d %d], %d iv_len\n",
226                         ds->buf_len, ds->cipher->key_len,
227                         DES_KEY_SZ, DES_SCHEDULE_SZ,
228                         ds->cipher->iv_len);
229 		printf("\t\tIV: ");
230 		for (i=0; i<ds->cipher->iv_len; i++) printf("%02X", ds->iv[i]);
231 		printf("\n");
232 		printf("\trec->input=");
233 		for (ui=0; ui<l; ui++) printf(" %02x", rec->input[ui]);
234 		printf("\n");
235 		}
236 #endif	/* KSSL_DEBUG */
237 
238 		if (!send)
239 			{
240 			if (l == 0 || l%bs != 0)
241 				return 0;
242 			}
243 
244 		EVP_Cipher(ds,rec->data,rec->input,l);
245 
246 #ifdef KSSL_DEBUG
247 		{
248                 unsigned long i;
249                 printf("\trec->data=");
250 		for (i=0; i<l; i++)
251                         printf(" %02x", rec->data[i]);  printf("\n");
252                 }
253 #endif	/* KSSL_DEBUG */
254 
255 		if ((bs != 1) && !send)
256 			return tls1_cbc_remove_padding(s, rec, bs, mac_size);
257 		}
258 	return(1);
259 	}
260 
261