1 /* $OpenBSD: d1_enc.c,v 1.10 2015/07/17 07:04:40 doug Exp $ */
3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
6 /* ====================================================================
7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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 * ====================================================================
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).
59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60 * All rights reserved.
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.
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).
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.
80 * Redistribution and use in source and binary forms, with or without
81 * modification, are permitted provided that the following conditions
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)"
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
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.]
118 #include "ssl_locl.h"
120 #include <openssl/evp.h>
121 #include <openssl/hmac.h>
122 #include <openssl/md5.h>
124 /* dtls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
127 * 0: (in non-constant time) if the record is publically invalid (i.e. too
129 * 1: if the record's padding is valid / the encryption was successful.
130 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
131 * an internal error occured. */
133 dtls1_enc(SSL
*s
, int send
)
138 int bs
, i
, j
, k
, mac_size
= 0;
139 const EVP_CIPHER
*enc
;
142 if (EVP_MD_CTX_md(s
->write_hash
)) {
143 mac_size
= EVP_MD_CTX_size(s
->write_hash
);
147 ds
= s
->enc_write_ctx
;
148 rec
= &(s
->s3
->wrec
);
149 if (s
->enc_write_ctx
== NULL
)
152 enc
= EVP_CIPHER_CTX_cipher(s
->enc_write_ctx
);
153 if (rec
->data
!= rec
->input
) {
155 /* we can't write into the input stream */
156 fprintf(stderr
, "%s:%d: rec->data != rec->input\n",
159 } else if (EVP_CIPHER_block_size(ds
->cipher
) > 1) {
160 arc4random_buf(rec
->input
,
161 EVP_CIPHER_block_size(ds
->cipher
));
165 if (EVP_MD_CTX_md(s
->read_hash
)) {
166 mac_size
= EVP_MD_CTX_size(s
->read_hash
);
167 OPENSSL_assert(mac_size
>= 0);
169 ds
= s
->enc_read_ctx
;
170 rec
= &(s
->s3
->rrec
);
171 if (s
->enc_read_ctx
== NULL
)
174 enc
= EVP_CIPHER_CTX_cipher(s
->enc_read_ctx
);
178 if ((s
->session
== NULL
) || (ds
== NULL
) || (enc
== NULL
)) {
179 memmove(rec
->data
, rec
->input
, rec
->length
);
180 rec
->input
= rec
->data
;
183 bs
= EVP_CIPHER_block_size(ds
->cipher
);
185 if ((bs
!= 1) && send
) {
186 i
= bs
- ((int)l
% bs
);
188 /* Add weird padding of upto 256 bytes */
190 /* we need to add 'i' padding bytes of value j */
192 for (k
= (int)l
; k
< (int)(l
+ i
); k
++)
200 if (l
== 0 || l
% bs
!= 0)
204 EVP_Cipher(ds
, rec
->data
, rec
->input
, l
);
207 if ((bs
!= 1) && !send
)
208 return tls1_cbc_remove_padding(s
, rec
, bs
, mac_size
);