diff options
Diffstat (limited to 'src/ssl/d1_pkt.cc')
| -rw-r--r-- | src/ssl/d1_pkt.cc | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/src/ssl/d1_pkt.cc b/src/ssl/d1_pkt.cc new file mode 100644 index 00000000..1ae55ebb --- /dev/null +++ b/src/ssl/d1_pkt.cc @@ -0,0 +1,417 @@ +/* DTLS implementation written by Nagendra Modadugu + * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. */ +/* ==================================================================== + * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. All advertising materials mentioning features or use of this + * software must display the following acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * openssl-core@openssl.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.openssl.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR + * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + * ==================================================================== + * + * This product includes cryptographic software written by Eric Young + * (eay@cryptsoft.com). This product includes software written by Tim + * Hudson (tjh@cryptsoft.com). + * + */ +/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) + * All rights reserved. + * + * This package is an SSL implementation written + * by Eric Young (eay@cryptsoft.com). + * The implementation was written so as to conform with Netscapes SSL. + * + * This library is free for commercial and non-commercial use as long as + * the following conditions are aheared to. The following conditions + * apply to all code found in this distribution, be it the RC4, RSA, + * lhash, DES, etc., code; not just the SSL code. The SSL documentation + * included with this distribution is covered by the same copyright terms + * except that the holder is Tim Hudson (tjh@cryptsoft.com). + * + * Copyright remains Eric Young's, and as such any Copyright notices in + * the code are not to be removed. + * If this package is used in a product, Eric Young should be given attribution + * as the author of the parts of the library used. + * This can be in the form of a textual message at program startup or + * in documentation (online or textual) provided with the package. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * "This product includes cryptographic software written by + * Eric Young (eay@cryptsoft.com)" + * The word 'cryptographic' can be left out if the rouines from the library + * being used are not cryptographic related :-). + * 4. If you include any Windows specific code (or a derivative thereof) from + * the apps directory (application code) you must include an acknowledgement: + * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" + * + * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * The licence and distribution terms for any publically available version or + * derivative of this code cannot be changed. i.e. this code cannot simply be + * copied and put under another distribution licence + * [including the GNU Public Licence.] */ + +#include <openssl/ssl.h> + +#include <assert.h> +#include <string.h> + +#include <openssl/bio.h> +#include <openssl/buf.h> +#include <openssl/bytestring.h> +#include <openssl/mem.h> +#include <openssl/evp.h> +#include <openssl/err.h> +#include <openssl/rand.h> + +#include "../crypto/internal.h" +#include "internal.h" + + +int dtls1_get_record(SSL *ssl) { +again: + switch (ssl->s3->recv_shutdown) { + case ssl_shutdown_none: + break; + case ssl_shutdown_fatal_alert: + OPENSSL_PUT_ERROR(SSL, SSL_R_PROTOCOL_IS_SHUTDOWN); + return -1; + case ssl_shutdown_close_notify: + return 0; + } + + /* Read a new packet if there is no unconsumed one. */ + if (ssl_read_buffer_len(ssl) == 0) { + int read_ret = ssl_read_buffer_extend_to(ssl, 0 /* unused */); + if (read_ret < 0 && dtls1_is_timer_expired(ssl)) { + /* Historically, timeouts were handled implicitly if the caller did not + * handle them. + * + * TODO(davidben): This was to support blocking sockets but affected + * non-blocking sockets. Can it be removed? */ + int timeout_ret = DTLSv1_handle_timeout(ssl); + if (timeout_ret <= 0) { + return timeout_ret; + } + goto again; + } + if (read_ret <= 0) { + return read_ret; + } + } + assert(ssl_read_buffer_len(ssl) > 0); + + CBS body; + uint8_t type, alert; + size_t consumed; + enum ssl_open_record_t open_ret = + dtls_open_record(ssl, &type, &body, &consumed, &alert, + ssl_read_buffer(ssl), ssl_read_buffer_len(ssl)); + ssl_read_buffer_consume(ssl, consumed); + switch (open_ret) { + case ssl_open_record_partial: + /* Impossible in DTLS. */ + break; + + case ssl_open_record_success: { + if (CBS_len(&body) > 0xffff) { + OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW); + return -1; + } + + SSL3_RECORD *rr = &ssl->s3->rrec; + rr->type = type; + rr->length = (uint16_t)CBS_len(&body); + rr->data = (uint8_t *)CBS_data(&body); + return 1; + } + + case ssl_open_record_discard: + goto again; + + case ssl_open_record_close_notify: + return 0; + + case ssl_open_record_fatal_alert: + return -1; + + case ssl_open_record_error: + ssl3_send_alert(ssl, SSL3_AL_FATAL, alert); + return -1; + } + + assert(0); + OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); + return -1; +} + +int dtls1_read_app_data(SSL *ssl, int *out_got_handshake, uint8_t *buf, int len, + int peek) { + assert(!SSL_in_init(ssl)); + + *out_got_handshake = 0; + SSL3_RECORD *rr = &ssl->s3->rrec; + +again: + if (rr->length == 0) { + int ret = dtls1_get_record(ssl); + if (ret <= 0) { + return ret; + } + } + + if (rr->type == SSL3_RT_HANDSHAKE) { + /* Parse the first fragment header to determine if this is a pre-CCS or + * post-CCS handshake record. DTLS resets handshake message numbers on each + * handshake, so renegotiations and retransmissions are ambiguous. */ + CBS cbs, body; + struct hm_header_st msg_hdr; + CBS_init(&cbs, rr->data, rr->length); + if (!dtls1_parse_fragment(&cbs, &msg_hdr, &body)) { + ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); + OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HANDSHAKE_RECORD); + return -1; + } + + if (msg_hdr.type == SSL3_MT_FINISHED && + msg_hdr.seq == ssl->d1->handshake_read_seq - 1) { + if (msg_hdr.frag_off == 0) { + /* Retransmit our last flight of messages. If the peer sends the second + * Finished, they may not have received ours. Only do this for the + * first fragment, in case the Finished was fragmented. */ + if (dtls1_check_timeout_num(ssl) < 0) { + return -1; + } + + dtls1_retransmit_outgoing_messages(ssl); + } + + rr->length = 0; + goto again; + } + + /* Otherwise, this is a pre-CCS handshake message from an unsupported + * renegotiation attempt. Fall through to the error path. */ + } + + if (rr->type != SSL3_RT_APPLICATION_DATA) { + ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); + OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD); + return -1; + } + + /* Discard empty records. */ + if (rr->length == 0) { + goto again; + } + + if (len <= 0) { + return len; + } + + if ((unsigned)len > rr->length) { + len = rr->length; + } + + OPENSSL_memcpy(buf, rr->data, len); + if (!peek) { + /* TODO(davidben): Should the record be truncated instead? This is a + * datagram transport. See https://crbug.com/boringssl/65. */ + rr->length -= len; + rr->data += len; + if (rr->length == 0) { + /* The record has been consumed, so we may now clear the buffer. */ + ssl_read_buffer_discard(ssl); + } + } + + return len; +} + +int dtls1_read_change_cipher_spec(SSL *ssl) { + SSL3_RECORD *rr = &ssl->s3->rrec; + +again: + if (rr->length == 0) { + int ret = dtls1_get_record(ssl); + if (ret <= 0) { + return ret; + } + } + + /* Drop handshake records silently. The epochs match, so this must be a + * retransmit of a message we already received. */ + if (rr->type == SSL3_RT_HANDSHAKE) { + rr->length = 0; + goto again; + } + + /* Other record types are illegal in this epoch. Note all application data + * records come in the encrypted epoch. */ + if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) { + ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); + OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD); + return -1; + } + + if (rr->length != 1 || rr->data[0] != SSL3_MT_CCS) { + OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_CHANGE_CIPHER_SPEC); + ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); + return -1; + } + + ssl_do_msg_callback(ssl, 0 /* read */, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, + rr->length); + + rr->length = 0; + ssl_read_buffer_discard(ssl); + return 1; +} + +void dtls1_read_close_notify(SSL *ssl) { + /* Bidirectional shutdown doesn't make sense for an unordered transport. DTLS + * alerts also aren't delivered reliably, so we may even time out because the + * peer never received our close_notify. Report to the caller that the channel + * has fully shut down. */ + if (ssl->s3->recv_shutdown == ssl_shutdown_none) { + ssl->s3->recv_shutdown = ssl_shutdown_close_notify; + } +} + +int dtls1_write_app_data(SSL *ssl, int *out_needs_handshake, const uint8_t *buf, + int len) { + assert(!SSL_in_init(ssl)); + *out_needs_handshake = 0; + + if (len > SSL3_RT_MAX_PLAIN_LENGTH) { + OPENSSL_PUT_ERROR(SSL, SSL_R_DTLS_MESSAGE_TOO_BIG); + return -1; + } + + if (len < 0) { + OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_LENGTH); + return -1; + } + + if (len == 0) { + return 0; + } + + int ret = dtls1_write_record(ssl, SSL3_RT_APPLICATION_DATA, buf, (size_t)len, + dtls1_use_current_epoch); + if (ret <= 0) { + return ret; + } + return len; +} + +int dtls1_write_record(SSL *ssl, int type, const uint8_t *buf, size_t len, + enum dtls1_use_epoch_t use_epoch) { + assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); + /* There should never be a pending write buffer in DTLS. One can't write half + * a datagram, so the write buffer is always dropped in + * |ssl_write_buffer_flush|. */ + assert(!ssl_write_buffer_is_pending(ssl)); + + if (len > SSL3_RT_MAX_PLAIN_LENGTH) { + OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); + return -1; + } + + size_t max_out = len + SSL_max_seal_overhead(ssl); + uint8_t *out; + size_t ciphertext_len; + if (!ssl_write_buffer_init(ssl, &out, max_out) || + !dtls_seal_record(ssl, out, &ciphertext_len, max_out, type, buf, len, + use_epoch)) { + ssl_write_buffer_clear(ssl); + return -1; + } + ssl_write_buffer_set_len(ssl, ciphertext_len); + + int ret = ssl_write_buffer_flush(ssl); + if (ret <= 0) { + return ret; + } + return 1; +} + +int dtls1_dispatch_alert(SSL *ssl) { + int ret = dtls1_write_record(ssl, SSL3_RT_ALERT, &ssl->s3->send_alert[0], 2, + dtls1_use_current_epoch); + if (ret <= 0) { + return ret; + } + ssl->s3->alert_dispatch = 0; + + /* If the alert is fatal, flush the BIO now. */ + if (ssl->s3->send_alert[0] == SSL3_AL_FATAL) { + BIO_flush(ssl->wbio); + } + + ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_ALERT, ssl->s3->send_alert, + 2); + + int alert = (ssl->s3->send_alert[0] << 8) | ssl->s3->send_alert[1]; + ssl_do_info_callback(ssl, SSL_CB_WRITE_ALERT, alert); + + return 1; +} |