1 /* DTLS implementation written by Nagendra Modadugu
2 * ([email protected]) for the OpenSSL project 2005. */
3 /* ====================================================================
4 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 *
18 * 3. All advertising materials mentioning features or use of this
19 * software must display the following acknowledgment:
20 * "This product includes software developed by the OpenSSL Project
21 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
22 *
23 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
24 * endorse or promote products derived from this software without
25 * prior written permission. For written permission, please contact
26 * [email protected].
27 *
28 * 5. Products derived from this software may not be called "OpenSSL"
29 * nor may "OpenSSL" appear in their names without prior written
30 * permission of the OpenSSL Project.
31 *
32 * 6. Redistributions of any form whatsoever must retain the following
33 * acknowledgment:
34 * "This product includes software developed by the OpenSSL Project
35 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
36 *
37 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
38 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
39 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
40 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
43 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
44 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
45 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
46 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
47 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
48 * OF THE POSSIBILITY OF SUCH DAMAGE.
49 * ====================================================================
50 *
51 * This product includes cryptographic software written by Eric Young
52 * ([email protected]). This product includes software written by Tim
53 * Hudson ([email protected]).
54 *
55 */
56 /* Copyright (C) 1995-1998 Eric Young ([email protected])
57 * All rights reserved.
58 *
59 * This package is an SSL implementation written
60 * by Eric Young ([email protected]).
61 * The implementation was written so as to conform with Netscapes SSL.
62 *
63 * This library is free for commercial and non-commercial use as long as
64 * the following conditions are aheared to. The following conditions
65 * apply to all code found in this distribution, be it the RC4, RSA,
66 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
67 * included with this distribution is covered by the same copyright terms
68 * except that the holder is Tim Hudson ([email protected]).
69 *
70 * Copyright remains Eric Young's, and as such any Copyright notices in
71 * the code are not to be removed.
72 * If this package is used in a product, Eric Young should be given attribution
73 * as the author of the parts of the library used.
74 * This can be in the form of a textual message at program startup or
75 * in documentation (online or textual) provided with the package.
76 *
77 * Redistribution and use in source and binary forms, with or without
78 * modification, are permitted provided that the following conditions
79 * are met:
80 * 1. Redistributions of source code must retain the copyright
81 * notice, this list of conditions and the following disclaimer.
82 * 2. Redistributions in binary form must reproduce the above copyright
83 * notice, this list of conditions and the following disclaimer in the
84 * documentation and/or other materials provided with the distribution.
85 * 3. All advertising materials mentioning features or use of this software
86 * must display the following acknowledgement:
87 * "This product includes cryptographic software written by
88 * Eric Young ([email protected])"
89 * The word 'cryptographic' can be left out if the rouines from the library
90 * being used are not cryptographic related :-).
91 * 4. If you include any Windows specific code (or a derivative thereof) from
92 * the apps directory (application code) you must include an acknowledgement:
93 * "This product includes software written by Tim Hudson ([email protected])"
94 *
95 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
96 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
97 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
98 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
99 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
100 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
101 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
102 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
103 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
104 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
105 * SUCH DAMAGE.
106 *
107 * The licence and distribution terms for any publically available version or
108 * derivative of this code cannot be changed. i.e. this code cannot simply be
109 * copied and put under another distribution licence
110 * [including the GNU Public Licence.] */
111
112 #include <openssl/ssl.h>
113
114 #include <assert.h>
115 #include <string.h>
116
117 #include <openssl/bio.h>
118 #include <openssl/bytestring.h>
119 #include <openssl/mem.h>
120 #include <openssl/evp.h>
121 #include <openssl/err.h>
122 #include <openssl/rand.h>
123
124 #include "../crypto/internal.h"
125 #include "internal.h"
126
127
128 BSSL_NAMESPACE_BEGIN
129
dtls1_open_app_data(SSL * ssl,Span<uint8_t> * out,size_t * out_consumed,uint8_t * out_alert,Span<uint8_t> in)130 ssl_open_record_t dtls1_open_app_data(SSL *ssl, Span<uint8_t> *out,
131 size_t *out_consumed, uint8_t *out_alert,
132 Span<uint8_t> in) {
133 assert(!SSL_in_init(ssl));
134
135 uint8_t type;
136 Span<uint8_t> record;
137 auto ret = dtls_open_record(ssl, &type, &record, out_consumed, out_alert, in);
138 if (ret != ssl_open_record_success) {
139 return ret;
140 }
141
142 if (type == SSL3_RT_HANDSHAKE) {
143 // Parse the first fragment header to determine if this is a pre-CCS or
144 // post-CCS handshake record. DTLS resets handshake message numbers on each
145 // handshake, so renegotiations and retransmissions are ambiguous.
146 CBS cbs, body;
147 struct hm_header_st msg_hdr;
148 CBS_init(&cbs, record.data(), record.size());
149 if (!dtls1_parse_fragment(&cbs, &msg_hdr, &body)) {
150 OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HANDSHAKE_RECORD);
151 *out_alert = SSL_AD_DECODE_ERROR;
152 return ssl_open_record_error;
153 }
154
155 if (msg_hdr.type == SSL3_MT_FINISHED &&
156 msg_hdr.seq == ssl->d1->handshake_read_seq - 1) {
157 if (msg_hdr.frag_off == 0) {
158 // Retransmit our last flight of messages. If the peer sends the second
159 // Finished, they may not have received ours. Only do this for the
160 // first fragment, in case the Finished was fragmented.
161 if (!dtls1_check_timeout_num(ssl)) {
162 *out_alert = 0; // TODO(davidben): Send an alert?
163 return ssl_open_record_error;
164 }
165
166 dtls1_retransmit_outgoing_messages(ssl);
167 }
168 return ssl_open_record_discard;
169 }
170
171 // Otherwise, this is a pre-CCS handshake message from an unsupported
172 // renegotiation attempt. Fall through to the error path.
173 }
174
175 if (type != SSL3_RT_APPLICATION_DATA) {
176 OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
177 *out_alert = SSL_AD_UNEXPECTED_MESSAGE;
178 return ssl_open_record_error;
179 }
180
181 if (record.empty()) {
182 return ssl_open_record_discard;
183 }
184
185 *out = record;
186 return ssl_open_record_success;
187 }
188
dtls1_write_app_data(SSL * ssl,bool * out_needs_handshake,size_t * out_bytes_written,Span<const uint8_t> in)189 int dtls1_write_app_data(SSL *ssl, bool *out_needs_handshake,
190 size_t *out_bytes_written, Span<const uint8_t> in) {
191 assert(!SSL_in_init(ssl));
192 *out_needs_handshake = false;
193
194 if (ssl->s3->write_shutdown != ssl_shutdown_none) {
195 OPENSSL_PUT_ERROR(SSL, SSL_R_PROTOCOL_IS_SHUTDOWN);
196 return -1;
197 }
198
199 // DTLS does not split the input across records.
200 if (in.size() > SSL3_RT_MAX_PLAIN_LENGTH) {
201 OPENSSL_PUT_ERROR(SSL, SSL_R_DTLS_MESSAGE_TOO_BIG);
202 return -1;
203 }
204
205 if (in.empty()) {
206 *out_bytes_written = 0;
207 return 1;
208 }
209
210 int ret = dtls1_write_record(ssl, SSL3_RT_APPLICATION_DATA, in,
211 ssl->d1->w_epoch);
212 if (ret <= 0) {
213 return ret;
214 }
215 *out_bytes_written = in.size();
216 return 1;
217 }
218
dtls_seal_align_prefix_len(const SSL * ssl,uint16_t epoch)219 static size_t dtls_seal_align_prefix_len(const SSL *ssl, uint16_t epoch) {
220 return dtls_record_header_write_len(ssl, epoch) +
221 ssl->s3->aead_write_ctx->ExplicitNonceLen();
222 }
223
dtls1_write_record(SSL * ssl,int type,Span<const uint8_t> in,uint16_t epoch)224 int dtls1_write_record(SSL *ssl, int type, Span<const uint8_t> in,
225 uint16_t epoch) {
226 SSLBuffer *buf = &ssl->s3->write_buffer;
227 assert(in.size() <= SSL3_RT_MAX_PLAIN_LENGTH);
228 // There should never be a pending write buffer in DTLS. One can't write half
229 // a datagram, so the write buffer is always dropped in
230 // |ssl_write_buffer_flush|.
231 assert(buf->empty());
232
233 if (in.size() > SSL3_RT_MAX_PLAIN_LENGTH) {
234 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
235 return -1;
236 }
237
238 size_t ciphertext_len;
239 if (!buf->EnsureCap(dtls_seal_align_prefix_len(ssl, epoch),
240 in.size() + SSL_max_seal_overhead(ssl)) ||
241 !dtls_seal_record(ssl, buf->remaining().data(), &ciphertext_len,
242 buf->remaining().size(), type, in.data(), in.size(),
243 epoch)) {
244 buf->Clear();
245 return -1;
246 }
247 buf->DidWrite(ciphertext_len);
248
249 int ret = ssl_write_buffer_flush(ssl);
250 if (ret <= 0) {
251 return ret;
252 }
253 return 1;
254 }
255
dtls1_dispatch_alert(SSL * ssl)256 int dtls1_dispatch_alert(SSL *ssl) {
257 int ret = dtls1_write_record(ssl, SSL3_RT_ALERT, ssl->s3->send_alert,
258 ssl->d1->w_epoch);
259 if (ret <= 0) {
260 return ret;
261 }
262 ssl->s3->alert_dispatch = false;
263
264 // If the alert is fatal, flush the BIO now.
265 if (ssl->s3->send_alert[0] == SSL3_AL_FATAL) {
266 BIO_flush(ssl->wbio.get());
267 }
268
269 ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_ALERT, ssl->s3->send_alert);
270
271 int alert = (ssl->s3->send_alert[0] << 8) | ssl->s3->send_alert[1];
272 ssl_do_info_callback(ssl, SSL_CB_WRITE_ALERT, alert);
273
274 return 1;
275 }
276
277 BSSL_NAMESPACE_END
278