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. */
137int 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