| /* 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/buf.h> |
| #include <openssl/mem.h> |
| #include <openssl/evp.h> |
| #include <openssl/err.h> |
| #include <openssl/rand.h> |
| |
| #include "internal.h" |
| |
| |
| static int do_dtls1_write(SSL *ssl, int type, const uint8_t *buf, |
| unsigned int len, enum dtls1_use_epoch_t use_epoch); |
| |
| /* dtls1_get_record reads a new input record. On success, it places it in |
| * |ssl->s3->rrec| and returns one. Otherwise it returns <= 0 on error or if |
| * more data is needed. */ |
| static 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 ret = ssl_read_buffer_extend_to(ssl, 0 /* unused */); |
| if (ret <= 0) { |
| return ret; |
| } |
| } |
| assert(ssl_read_buffer_len(ssl) > 0); |
| |
| /* Ensure the packet is large enough to decrypt in-place. */ |
| if (ssl_read_buffer_len(ssl) < ssl_record_prefix_len(ssl)) { |
| ssl_read_buffer_clear(ssl); |
| goto again; |
| } |
| |
| uint8_t *out = ssl_read_buffer(ssl) + ssl_record_prefix_len(ssl); |
| size_t max_out = ssl_read_buffer_len(ssl) - ssl_record_prefix_len(ssl); |
| uint8_t type, alert; |
| size_t len, consumed; |
| switch (dtls_open_record(ssl, &type, out, &len, &consumed, &alert, max_out, |
| ssl_read_buffer(ssl), ssl_read_buffer_len(ssl))) { |
| case ssl_open_record_success: |
| ssl_read_buffer_consume(ssl, consumed); |
| |
| if (len > 0xffff) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW); |
| return -1; |
| } |
| |
| SSL3_RECORD *rr = &ssl->s3->rrec; |
| rr->type = type; |
| rr->length = (uint16_t)len; |
| rr->data = out; |
| return 1; |
| |
| case ssl_open_record_discard: |
| ssl_read_buffer_consume(ssl, consumed); |
| goto again; |
| |
| case ssl_open_record_error: |
| ssl3_send_alert(ssl, SSL3_AL_FATAL, alert); |
| return -1; |
| |
| case ssl_open_record_partial: |
| /* Impossible in DTLS. */ |
| break; |
| } |
| |
| assert(0); |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return -1; |
| } |
| |
| int dtls1_read_app_data(SSL *ssl, uint8_t *buf, int len, int peek) { |
| assert(!SSL_in_init(ssl)); |
| return dtls1_read_bytes(ssl, SSL3_RT_APPLICATION_DATA, buf, len, peek); |
| } |
| |
| int dtls1_read_change_cipher_spec(SSL *ssl) { |
| uint8_t byte; |
| int ret = dtls1_read_bytes(ssl, SSL3_RT_CHANGE_CIPHER_SPEC, &byte, |
| 1 /* len */, 0 /* no peek */); |
| if (ret <= 0) { |
| return ret; |
| } |
| assert(ret == 1); |
| |
| if (ssl->s3->rrec.length != 0 || byte != 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; |
| } |
| |
| if (ssl->msg_callback != NULL) { |
| ssl->msg_callback(0, ssl->version, SSL3_RT_CHANGE_CIPHER_SPEC, &byte, 1, |
| ssl, ssl->msg_callback_arg); |
| } |
| |
| 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; |
| } |
| } |
| |
| /* Return up to 'len' payload bytes received in 'type' records. |
| * 'type' is one of the following: |
| * |
| * - SSL3_RT_HANDSHAKE (when dtls1_get_message calls us) |
| * - SSL3_RT_CHANGE_CIPHER_SPEC (when dtls1_read_change_cipher_spec calls us) |
| * - SSL3_RT_APPLICATION_DATA (when dtls1_read_app_data calls us) |
| * |
| * If we don't have stored data to work from, read a DTLS record first (possibly |
| * multiple records if we still don't have anything to return). |
| * |
| * This function must handle any surprises the peer may have for us, such as |
| * Alert records (e.g. close_notify) and out of records. */ |
| int dtls1_read_bytes(SSL *ssl, int type, unsigned char *buf, int len, int peek) { |
| int al, ret; |
| unsigned int n; |
| SSL3_RECORD *rr; |
| void (*cb)(const SSL *ssl, int type, int value) = NULL; |
| |
| if ((type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE && |
| type != SSL3_RT_CHANGE_CIPHER_SPEC) || |
| (peek && type != SSL3_RT_APPLICATION_DATA)) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return -1; |
| } |
| |
| start: |
| /* ssl->s3->rrec.type - is the type of record |
| * ssl->s3->rrec.data - data |
| * ssl->s3->rrec.off - offset into 'data' for next read |
| * ssl->s3->rrec.length - number of bytes. */ |
| rr = &ssl->s3->rrec; |
| |
| /* Check for timeout */ |
| if (DTLSv1_handle_timeout(ssl) > 0) { |
| goto start; |
| } |
| |
| /* get new packet if necessary */ |
| if (rr->length == 0) { |
| ret = dtls1_get_record(ssl); |
| if (ret <= 0) { |
| ret = dtls1_read_failed(ssl, ret); |
| /* anything other than a timeout is an error */ |
| if (ret <= 0) { |
| return ret; |
| } else { |
| goto start; |
| } |
| } |
| } |
| |
| /* we now have a packet which can be read and processed */ |
| |
| if (type == rr->type) { |
| /* Discard empty records. */ |
| if (rr->length == 0) { |
| goto start; |
| } |
| |
| if (len <= 0) { |
| return len; |
| } |
| |
| if ((unsigned int)len > rr->length) { |
| n = rr->length; |
| } else { |
| n = (unsigned int)len; |
| } |
| |
| memcpy(buf, rr->data, n); |
| if (!peek) { |
| rr->length -= n; |
| rr->data += n; |
| if (rr->length == 0) { |
| /* The record has been consumed, so we may now clear the buffer. */ |
| ssl_read_buffer_discard(ssl); |
| } |
| } |
| |
| return n; |
| } |
| |
| /* If we get here, then type != rr->type. */ |
| |
| /* If an alert record, process the alert. */ |
| if (rr->type == SSL3_RT_ALERT) { |
| /* Alerts records may not contain fragmented or multiple alerts. */ |
| if (rr->length != 2) { |
| al = SSL_AD_DECODE_ERROR; |
| OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT); |
| goto f_err; |
| } |
| |
| if (ssl->msg_callback) { |
| ssl->msg_callback(0, ssl->version, SSL3_RT_ALERT, rr->data, 2, ssl, |
| ssl->msg_callback_arg); |
| } |
| const uint8_t alert_level = rr->data[0]; |
| const uint8_t alert_descr = rr->data[1]; |
| rr->length -= 2; |
| rr->data += 2; |
| |
| if (ssl->info_callback != NULL) { |
| cb = ssl->info_callback; |
| } else if (ssl->ctx->info_callback != NULL) { |
| cb = ssl->ctx->info_callback; |
| } |
| |
| if (cb != NULL) { |
| uint16_t alert = (alert_level << 8) | alert_descr; |
| cb(ssl, SSL_CB_READ_ALERT, alert); |
| } |
| |
| if (alert_level == SSL3_AL_WARNING) { |
| if (alert_descr == SSL_AD_CLOSE_NOTIFY) { |
| ssl->s3->recv_shutdown = ssl_shutdown_close_notify; |
| return 0; |
| } |
| } else if (alert_level == SSL3_AL_FATAL) { |
| char tmp[16]; |
| |
| OPENSSL_PUT_ERROR(SSL, SSL_AD_REASON_OFFSET + alert_descr); |
| BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr); |
| ERR_add_error_data(2, "SSL alert number ", tmp); |
| ssl->s3->recv_shutdown = ssl_shutdown_fatal_alert; |
| SSL_CTX_remove_session(ssl->ctx, ssl->session); |
| return 0; |
| } else { |
| al = SSL_AD_ILLEGAL_PARAMETER; |
| OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_ALERT_TYPE); |
| goto f_err; |
| } |
| |
| goto start; |
| } |
| |
| /* Cross-epoch records are discarded, but we may receive out-of-order |
| * application data between ChangeCipherSpec and Finished or a ChangeCipherSpec |
| * before the appropriate point in the handshake. Those must be silently |
| * discarded. |
| * |
| * However, only allow the out-of-order records in the correct epoch. |
| * Application data must come in the encrypted epoch, and ChangeCipherSpec in |
| * the unencrypted epoch (we never renegotiate). Other cases fall through and |
| * fail with a fatal error. */ |
| if ((rr->type == SSL3_RT_APPLICATION_DATA && |
| ssl->s3->aead_read_ctx != NULL) || |
| (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC && |
| ssl->s3->aead_read_ctx == NULL)) { |
| rr->length = 0; |
| goto start; |
| } |
| |
| if (rr->type == SSL3_RT_HANDSHAKE) { |
| if (type != SSL3_RT_APPLICATION_DATA) { |
| /* Out-of-order handshake record while looking for ChangeCipherSpec. Drop |
| * it silently. */ |
| assert(type == SSL3_RT_CHANGE_CIPHER_SPEC); |
| rr->length = 0; |
| goto start; |
| } |
| |
| /* 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. */ |
| if (rr->length < DTLS1_HM_HEADER_LENGTH) { |
| al = SSL_AD_DECODE_ERROR; |
| OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HANDSHAKE_RECORD); |
| goto f_err; |
| } |
| struct hm_header_st msg_hdr; |
| dtls1_get_message_header(rr->data, &msg_hdr); |
| |
| if (msg_hdr.type == SSL3_MT_FINISHED) { |
| 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_buffered_messages(ssl); |
| } |
| |
| rr->length = 0; |
| goto start; |
| } |
| |
| /* Otherwise, this is a pre-CCS handshake message from an unsupported |
| * renegotiation attempt. Fall through to the error path. */ |
| } |
| |
| al = SSL_AD_UNEXPECTED_MESSAGE; |
| OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD); |
| |
| f_err: |
| ssl3_send_alert(ssl, SSL3_AL_FATAL, al); |
| return -1; |
| } |
| |
| int dtls1_write_app_data(SSL *ssl, const void *buf_, int len) { |
| assert(!SSL_in_init(ssl)); |
| |
| if (len > SSL3_RT_MAX_PLAIN_LENGTH) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DTLS_MESSAGE_TOO_BIG); |
| return -1; |
| } |
| |
| return dtls1_write_bytes(ssl, SSL3_RT_APPLICATION_DATA, buf_, len, |
| dtls1_use_current_epoch); |
| } |
| |
| /* Call this to write data in records of type 'type' It will return <= 0 if not |
| * all data has been sent or non-blocking IO. */ |
| int dtls1_write_bytes(SSL *ssl, int type, const void *buf, int len, |
| enum dtls1_use_epoch_t use_epoch) { |
| assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); |
| return do_dtls1_write(ssl, type, buf, len, use_epoch); |
| } |
| |
| static int do_dtls1_write(SSL *ssl, int type, const uint8_t *buf, |
| unsigned int len, enum dtls1_use_epoch_t use_epoch) { |
| /* 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 we have an alert to send, lets send it */ |
| if (ssl->s3->alert_dispatch) { |
| int ret = ssl->method->ssl_dispatch_alert(ssl); |
| if (ret <= 0) { |
| return ret; |
| } |
| /* if it went, fall through and send more stuff */ |
| } |
| |
| if (len > SSL3_RT_MAX_PLAIN_LENGTH) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return -1; |
| } |
| |
| if (len == 0) { |
| return 0; |
| } |
| |
| 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 (int)len; |
| } |
| |
| int dtls1_dispatch_alert(SSL *ssl) { |
| ssl->s3->alert_dispatch = 0; |
| int ret = do_dtls1_write(ssl, SSL3_RT_ALERT, &ssl->s3->send_alert[0], 2, |
| dtls1_use_current_epoch); |
| if (ret <= 0) { |
| ssl->s3->alert_dispatch = 1; |
| return ret; |
| } |
| |
| /* If the alert is fatal, flush the BIO now. */ |
| if (ssl->s3->send_alert[0] == SSL3_AL_FATAL) { |
| BIO_flush(ssl->wbio); |
| } |
| |
| if (ssl->msg_callback != NULL) { |
| ssl->msg_callback(1 /* write */, ssl->version, SSL3_RT_ALERT, |
| ssl->s3->send_alert, 2, ssl, ssl->msg_callback_arg); |
| } |
| |
| void (*cb)(const SSL *ssl, int type, int value) = NULL; |
| if (ssl->info_callback != NULL) { |
| cb = ssl->info_callback; |
| } else if (ssl->ctx->info_callback != NULL) { |
| cb = ssl->ctx->info_callback; |
| } |
| |
| if (cb != NULL) { |
| int alert = (ssl->s3->send_alert[0] << 8) | ssl->s3->send_alert[1]; |
| cb(ssl, SSL_CB_WRITE_ALERT, alert); |
| } |
| |
| return 1; |
| } |