1 /* DTLS implementation written by Nagendra Modadugu 2 * (nagendra (at) cs.stanford.edu) 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 * openssl-core (at) openssl.org. 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 * (eay (at) cryptsoft.com). This product includes software written by Tim 53 * Hudson (tjh (at) cryptsoft.com). 54 * 55 */ 56 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 57 * All rights reserved. 58 * 59 * This package is an SSL implementation written 60 * by Eric Young (eay (at) cryptsoft.com). 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 (tjh (at) cryptsoft.com). 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 (eay (at) cryptsoft.com)" 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 (tjh (at) cryptsoft.com)" 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/buf.h> 119 #include <openssl/bytestring.h> 120 #include <openssl/mem.h> 121 #include <openssl/evp.h> 122 #include <openssl/err.h> 123 #include <openssl/rand.h> 124 125 #include "../crypto/internal.h" 126 #include "internal.h" 127 128 129 namespace bssl { 130 131 ssl_open_record_t dtls1_open_app_data(SSL *ssl, Span<uint8_t> *out, 132 size_t *out_consumed, uint8_t *out_alert, 133 Span<uint8_t> in) { 134 assert(!SSL_in_init(ssl)); 135 136 uint8_t type; 137 Span<uint8_t> record; 138 auto ret = dtls_open_record(ssl, &type, &record, out_consumed, out_alert, in); 139 if (ret != ssl_open_record_success) { 140 return ret; 141 } 142 143 if (type == SSL3_RT_HANDSHAKE) { 144 // Parse the first fragment header to determine if this is a pre-CCS or 145 // post-CCS handshake record. DTLS resets handshake message numbers on each 146 // handshake, so renegotiations and retransmissions are ambiguous. 147 CBS cbs, body; 148 struct hm_header_st msg_hdr; 149 CBS_init(&cbs, record.data(), record.size()); 150 if (!dtls1_parse_fragment(&cbs, &msg_hdr, &body)) { 151 OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HANDSHAKE_RECORD); 152 *out_alert = SSL_AD_DECODE_ERROR; 153 return ssl_open_record_error; 154 } 155 156 if (msg_hdr.type == SSL3_MT_FINISHED && 157 msg_hdr.seq == ssl->d1->handshake_read_seq - 1) { 158 if (msg_hdr.frag_off == 0) { 159 // Retransmit our last flight of messages. If the peer sends the second 160 // Finished, they may not have received ours. Only do this for the 161 // first fragment, in case the Finished was fragmented. 162 if (!dtls1_check_timeout_num(ssl)) { 163 *out_alert = 0; // TODO(davidben): Send an alert? 164 return ssl_open_record_error; 165 } 166 167 dtls1_retransmit_outgoing_messages(ssl); 168 } 169 return ssl_open_record_discard; 170 } 171 172 // Otherwise, this is a pre-CCS handshake message from an unsupported 173 // renegotiation attempt. Fall through to the error path. 174 } 175 176 if (type != SSL3_RT_APPLICATION_DATA) { 177 OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD); 178 *out_alert = SSL_AD_UNEXPECTED_MESSAGE; 179 return ssl_open_record_error; 180 } 181 182 if (record.empty()) { 183 return ssl_open_record_discard; 184 } 185 186 *out = record; 187 return ssl_open_record_success; 188 } 189 190 int dtls1_write_app_data(SSL *ssl, bool *out_needs_handshake, const uint8_t *in, 191 int len) { 192 assert(!SSL_in_init(ssl)); 193 *out_needs_handshake = false; 194 195 if (ssl->s3->write_shutdown != ssl_shutdown_none) { 196 OPENSSL_PUT_ERROR(SSL, SSL_R_PROTOCOL_IS_SHUTDOWN); 197 return -1; 198 } 199 200 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 201 OPENSSL_PUT_ERROR(SSL, SSL_R_DTLS_MESSAGE_TOO_BIG); 202 return -1; 203 } 204 205 if (len < 0) { 206 OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_LENGTH); 207 return -1; 208 } 209 210 if (len == 0) { 211 return 0; 212 } 213 214 int ret = dtls1_write_record(ssl, SSL3_RT_APPLICATION_DATA, in, (size_t)len, 215 dtls1_use_current_epoch); 216 if (ret <= 0) { 217 return ret; 218 } 219 return len; 220 } 221 222 int dtls1_write_record(SSL *ssl, int type, const uint8_t *in, size_t len, 223 enum dtls1_use_epoch_t use_epoch) { 224 SSLBuffer *buf = &ssl->s3->write_buffer; 225 assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 226 // There should never be a pending write buffer in DTLS. One can't write half 227 // a datagram, so the write buffer is always dropped in 228 // |ssl_write_buffer_flush|. 229 assert(buf->empty()); 230 231 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 232 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); 233 return -1; 234 } 235 236 size_t ciphertext_len; 237 if (!buf->EnsureCap(ssl_seal_align_prefix_len(ssl), 238 len + SSL_max_seal_overhead(ssl)) || 239 !dtls_seal_record(ssl, buf->remaining().data(), &ciphertext_len, 240 buf->remaining().size(), type, in, len, use_epoch)) { 241 buf->Clear(); 242 return -1; 243 } 244 buf->DidWrite(ciphertext_len); 245 246 int ret = ssl_write_buffer_flush(ssl); 247 if (ret <= 0) { 248 return ret; 249 } 250 return 1; 251 } 252 253 int dtls1_dispatch_alert(SSL *ssl) { 254 int ret = dtls1_write_record(ssl, SSL3_RT_ALERT, &ssl->s3->send_alert[0], 2, 255 dtls1_use_current_epoch); 256 if (ret <= 0) { 257 return ret; 258 } 259 ssl->s3->alert_dispatch = 0; 260 261 // If the alert is fatal, flush the BIO now. 262 if (ssl->s3->send_alert[0] == SSL3_AL_FATAL) { 263 BIO_flush(ssl->wbio); 264 } 265 266 ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_ALERT, ssl->s3->send_alert); 267 268 int alert = (ssl->s3->send_alert[0] << 8) | ssl->s3->send_alert[1]; 269 ssl_do_info_callback(ssl, SSL_CB_WRITE_ALERT, alert); 270 271 return 1; 272 } 273 274 } // namespace bssl 275
