|
- /* 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 <assert.h>
- #include <stdio.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"
-
-
- /* mod 128 saturating subtract of two 64-bit values in big-endian order */
- static int satsub64be(const uint8_t *v1, const uint8_t *v2) {
- int ret, sat, brw, i;
-
- if (sizeof(long) == 8) {
- do {
- const union {
- long one;
- char little;
- } is_endian = {1};
- long l;
-
- if (is_endian.little) {
- break;
- }
- /* not reached on little-endians */
- /* following test is redundant, because input is
- * always aligned, but I take no chances... */
- if (((size_t)v1 | (size_t)v2) & 0x7) {
- break;
- }
-
- l = *((long *)v1);
- l -= *((long *)v2);
- if (l > 128) {
- return 128;
- } else if (l < -128) {
- return -128;
- } else {
- return (int)l;
- }
- } while (0);
- }
-
- ret = (int)v1[7] - (int)v2[7];
- sat = 0;
- brw = ret >> 8; /* brw is either 0 or -1 */
- if (ret & 0x80) {
- for (i = 6; i >= 0; i--) {
- brw += (int)v1[i] - (int)v2[i];
- sat |= ~brw;
- brw >>= 8;
- }
- } else {
- for (i = 6; i >= 0; i--) {
- brw += (int)v1[i] - (int)v2[i];
- sat |= brw;
- brw >>= 8;
- }
- }
- brw <<= 8; /* brw is either 0 or -256 */
-
- if (sat & 0xff) {
- return brw | 0x80;
- } else {
- return brw + (ret & 0xFF);
- }
- }
-
- static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
- static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
- static int dtls1_process_record(SSL *s);
- static int do_dtls1_write(SSL *s, int type, const uint8_t *buf,
- unsigned int len, enum dtls1_use_epoch_t use_epoch);
-
- static int dtls1_process_record(SSL *s) {
- int al;
- SSL3_RECORD *rr = &s->s3->rrec;
-
- /* check is not needed I believe */
- if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
- al = SSL_AD_RECORD_OVERFLOW;
- OPENSSL_PUT_ERROR(SSL, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
- goto f_err;
- }
-
- /* |rr->data| points to |rr->length| bytes of ciphertext in |s->packet|. */
- rr->data = &s->packet[DTLS1_RT_HEADER_LENGTH];
-
- uint8_t seq[8];
- seq[0] = rr->epoch >> 8;
- seq[1] = rr->epoch & 0xff;
- memcpy(&seq[2], &rr->seq_num[2], 6);
-
- /* Decrypt the packet in-place. Note it is important that |SSL_AEAD_CTX_open|
- * not write beyond |rr->length|. There may be another record in the packet.
- *
- * TODO(davidben): This assumes |s->version| is the same as the record-layer
- * version which isn't always true, but it only differs with the NULL cipher
- * which ignores the parameter. */
- size_t plaintext_len;
- if (!SSL_AEAD_CTX_open(s->aead_read_ctx, rr->data, &plaintext_len, rr->length,
- rr->type, s->version, seq, rr->data, rr->length)) {
- /* Bad packets are silently dropped in DTLS. Clear the error queue of any
- * errors decryption may have added. */
- ERR_clear_error();
- rr->length = 0;
- s->packet_length = 0;
- goto err;
- }
-
- if (plaintext_len > SSL3_RT_MAX_PLAIN_LENGTH) {
- al = SSL_AD_RECORD_OVERFLOW;
- OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_LENGTH_TOO_LONG);
- goto f_err;
- }
- assert(plaintext_len < (1u << 16));
- rr->length = plaintext_len;
-
- rr->off = 0;
- /* So at this point the following is true
- * ssl->s3->rrec.type is the type of record
- * ssl->s3->rrec.length == number of bytes in record
- * ssl->s3->rrec.off == offset to first valid byte
- * ssl->s3->rrec.data == the first byte of the record body. */
-
- /* we have pulled in a full packet so zero things */
- s->packet_length = 0;
- return 1;
-
- f_err:
- ssl3_send_alert(s, SSL3_AL_FATAL, al);
-
- err:
- return 0;
- }
-
- /* Call this to get a new input record.
- * It will return <= 0 if more data is needed, normally due to an error
- * or non-blocking IO.
- * When it finishes, one packet has been decoded and can be found in
- * ssl->s3->rrec.type - is the type of record
- * ssl->s3->rrec.data, - data
- * ssl->s3->rrec.length, - number of bytes
- *
- * used only by dtls1_read_bytes */
- int dtls1_get_record(SSL *s) {
- uint8_t ssl_major, ssl_minor;
- int n;
- SSL3_RECORD *rr;
- uint8_t *p = NULL;
- uint16_t version;
-
- rr = &(s->s3->rrec);
-
- /* get something from the wire */
- again:
- /* check if we have the header */
- if ((s->rstate != SSL_ST_READ_BODY) ||
- (s->packet_length < DTLS1_RT_HEADER_LENGTH)) {
- n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, 0);
- /* read timeout is handled by dtls1_read_bytes */
- if (n <= 0) {
- return n; /* error or non-blocking */
- }
-
- /* this packet contained a partial record, dump it */
- if (s->packet_length != DTLS1_RT_HEADER_LENGTH) {
- s->packet_length = 0;
- goto again;
- }
-
- s->rstate = SSL_ST_READ_BODY;
-
- p = s->packet;
-
- if (s->msg_callback) {
- s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s,
- s->msg_callback_arg);
- }
-
- /* Pull apart the header into the DTLS1_RECORD */
- rr->type = *(p++);
- ssl_major = *(p++);
- ssl_minor = *(p++);
- version = (((uint16_t)ssl_major) << 8) | ssl_minor;
-
- /* sequence number is 64 bits, with top 2 bytes = epoch */
- n2s(p, rr->epoch);
-
- memcpy(&(s->s3->read_sequence[2]), p, 6);
- p += 6;
-
- n2s(p, rr->length);
-
- /* Lets check version */
- if (s->s3->have_version) {
- if (version != s->version) {
- /* The record's version doesn't match, so silently drop it.
- *
- * TODO(davidben): This doesn't work. The DTLS record layer is not
- * packet-based, so the remainder of the packet isn't dropped and we
- * get a framing error. It's also unclear what it means to silently
- * drop a record in a packet containing two records. */
- rr->length = 0;
- s->packet_length = 0;
- goto again;
- }
- }
-
- if ((version & 0xff00) != (s->version & 0xff00)) {
- /* wrong version, silently discard record */
- rr->length = 0;
- s->packet_length = 0;
- goto again;
- }
-
- if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
- /* record too long, silently discard it */
- rr->length = 0;
- s->packet_length = 0;
- goto again;
- }
-
- /* now s->rstate == SSL_ST_READ_BODY */
- }
-
- /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
-
- if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) {
- /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
- n = ssl3_read_n(s, rr->length, 1);
- /* This packet contained a partial record, dump it. */
- if (n != rr->length) {
- rr->length = 0;
- s->packet_length = 0;
- goto again;
- }
-
- /* now n == rr->length,
- * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
- }
- s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */
-
- if (rr->epoch != s->d1->r_epoch) {
- /* This record is from the wrong epoch. If it is the next epoch, it could be
- * buffered. For simplicity, drop it and expect retransmit to handle it
- * later; DTLS is supposed to handle packet loss. */
- rr->length = 0;
- s->packet_length = 0;
- goto again;
- }
-
- /* Check whether this is a repeat, or aged record. */
- if (!dtls1_record_replay_check(s, &s->d1->bitmap)) {
- rr->length = 0;
- s->packet_length = 0; /* dump this record */
- goto again; /* get another record */
- }
-
- /* just read a 0 length packet */
- if (rr->length == 0) {
- goto again;
- }
-
- if (!dtls1_process_record(s)) {
- rr->length = 0;
- s->packet_length = 0; /* dump this record */
- goto again; /* get another record */
- }
- dtls1_record_bitmap_update(s, &s->d1->bitmap); /* Mark receipt of record. */
-
- return 1;
- }
-
- int dtls1_read_app_data(SSL *ssl, uint8_t *buf, int len, int peek) {
- return dtls1_read_bytes(ssl, SSL3_RT_APPLICATION_DATA, buf, len, peek);
- }
-
- void dtls1_read_close_notify(SSL *ssl) {
- dtls1_read_bytes(ssl, 0, NULL, 0, 0);
- }
-
- /* Return up to 'len' payload bytes received in 'type' records.
- * 'type' is one of the following:
- *
- * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
- * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
- * - 0 (during a shutdown, no data has to be returned)
- *
- * If we don't have stored data to work from, read a SSL/TLS 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), ChangeCipherSpec records (not really
- * a surprise, but handled as if it were), or renegotiation requests.
- * Also if record payloads contain fragments too small to process, we store
- * them until there is enough for the respective protocol (the record protocol
- * may use arbitrary fragmentation and even interleaving):
- * Change cipher spec protocol
- * just 1 byte needed, no need for keeping anything stored
- * Alert protocol
- * 2 bytes needed (AlertLevel, AlertDescription)
- * Handshake protocol
- * 4 bytes needed (HandshakeType, uint24 length) -- we just have
- * to detect unexpected Client Hello and Hello Request messages
- * here, anything else is handled by higher layers
- * Application data protocol
- * none of our business
- */
- int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) {
- int al, i, ret;
- unsigned int n;
- SSL3_RECORD *rr;
- void (*cb)(const SSL *ssl, int type2, int val) = NULL;
-
- /* XXX: check what the second '&& type' is about */
- if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
- (type != SSL3_RT_HANDSHAKE) && type) ||
- (peek && (type != SSL3_RT_APPLICATION_DATA))) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return -1;
- }
-
- if (!s->in_handshake && SSL_in_init(s)) {
- /* type == SSL3_RT_APPLICATION_DATA */
- i = s->handshake_func(s);
- if (i < 0) {
- return i;
- }
- if (i == 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
- return -1;
- }
- }
-
- start:
- s->rwstate = SSL_NOTHING;
-
- /* s->s3->rrec.type - is the type of record
- * s->s3->rrec.data - data
- * s->s3->rrec.off - offset into 'data' for next read
- * s->s3->rrec.length - number of bytes. */
- rr = &s->s3->rrec;
-
- /* Check for timeout */
- if (DTLSv1_handle_timeout(s) > 0) {
- goto start;
- }
-
- /* get new packet if necessary */
- if (rr->length == 0 || s->rstate == SSL_ST_READ_BODY) {
- ret = dtls1_get_record(s);
- if (ret <= 0) {
- ret = dtls1_read_failed(s, 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 */
-
- /* |change_cipher_spec is set when we receive a ChangeCipherSpec and reset by
- * ssl3_get_finished. */
- if (s->s3->change_cipher_spec && rr->type != SSL3_RT_HANDSHAKE &&
- rr->type != SSL3_RT_ALERT) {
- /* We now have an unexpected record between CCS and Finished. Most likely
- * the packets were reordered on their way. DTLS is unreliable, so drop the
- * packet and expect the peer to retransmit. */
- rr->length = 0;
- goto start;
- }
-
- /* If the other end has shut down, throw anything we read away (even in
- * 'peek' mode) */
- if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
- rr->length = 0;
- s->rwstate = SSL_NOTHING;
- return 0;
- }
-
-
- if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
- /* make sure that we are not getting application data when we
- * are doing a handshake for the first time */
- if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
- (s->aead_read_ctx == NULL)) {
- /* TODO(davidben): Is this check redundant with the handshake_func
- * check? */
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, SSL_R_APP_DATA_IN_HANDSHAKE);
- goto f_err;
- }
-
- if (len <= 0) {
- return len;
- }
-
- if ((unsigned int)len > rr->length) {
- n = rr->length;
- } else {
- n = (unsigned int)len;
- }
-
- memcpy(buf, &(rr->data[rr->off]), n);
- if (!peek) {
- rr->length -= n;
- rr->off += n;
- if (rr->length == 0) {
- s->rstate = SSL_ST_READ_HEADER;
- rr->off = 0;
- }
- }
-
- return n;
- }
-
- /* If we get here, then type != rr->type. */
-
- /* If an alert record, process one alert out of the record. Note that we allow
- * a single record to contain multiple alerts. */
- if (rr->type == SSL3_RT_ALERT) {
- /* Alerts may not be fragmented. */
- if (rr->length < 2) {
- al = SSL_AD_DECODE_ERROR;
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT);
- goto f_err;
- }
-
- if (s->msg_callback) {
- s->msg_callback(0, s->version, SSL3_RT_ALERT, &rr->data[rr->off], 2, s,
- s->msg_callback_arg);
- }
- const uint8_t alert_level = rr->data[rr->off++];
- const uint8_t alert_descr = rr->data[rr->off++];
- rr->length -= 2;
-
- if (s->info_callback != NULL) {
- cb = s->info_callback;
- } else if (s->ctx->info_callback != NULL) {
- cb = s->ctx->info_callback;
- }
-
- if (cb != NULL) {
- uint16_t alert = (alert_level << 8) | alert_descr;
- cb(s, SSL_CB_READ_ALERT, alert);
- }
-
- if (alert_level == SSL3_AL_WARNING) {
- s->s3->warn_alert = alert_descr;
- if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
- s->shutdown |= SSL_RECEIVED_SHUTDOWN;
- return 0;
- }
- } else if (alert_level == SSL3_AL_FATAL) {
- char tmp[16];
-
- s->rwstate = SSL_NOTHING;
- s->s3->fatal_alert = alert_descr;
- 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);
- s->shutdown |= SSL_RECEIVED_SHUTDOWN;
- SSL_CTX_remove_session(s->ctx, s->session);
- return 0;
- } else {
- al = SSL_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_ALERT_TYPE);
- goto f_err;
- }
-
- goto start;
- }
-
- if (s->shutdown & SSL_SENT_SHUTDOWN) {
- /* but we have not received a shutdown */
- s->rwstate = SSL_NOTHING;
- rr->length = 0;
- return 0;
- }
-
- if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
- /* 'Change Cipher Spec' is just a single byte, so we know exactly what the
- * record payload has to look like */
- if (rr->length != 1 || rr->off != 0 || rr->data[0] != SSL3_MT_CCS) {
- al = SSL_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_CHANGE_CIPHER_SPEC);
- goto f_err;
- }
-
- rr->length = 0;
-
- if (s->msg_callback) {
- s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s,
- s->msg_callback_arg);
- }
-
- /* We can't process a CCS now, because previous handshake
- * messages are still missing, so just drop it.
- */
- if (!s->d1->change_cipher_spec_ok) {
- goto start;
- }
-
- s->d1->change_cipher_spec_ok = 0;
-
- s->s3->change_cipher_spec = 1;
- if (!ssl3_do_change_cipher_spec(s)) {
- goto err;
- }
-
- /* do this whenever CCS is processed */
- dtls1_reset_seq_numbers(s, SSL3_CC_READ);
-
- goto start;
- }
-
- /* Unexpected handshake message. It may be a retransmitted Finished (the only
- * post-CCS message). Otherwise, it's a pre-CCS handshake message from an
- * unsupported renegotiation attempt. */
- if (rr->type == SSL3_RT_HANDSHAKE && !s->in_handshake) {
- 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[rr->off], &msg_hdr);
-
- /* Ignore a stray Finished from the previous handshake. */
- 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(s) < 0) {
- return -1;
- }
-
- dtls1_retransmit_buffered_messages(s);
- }
-
- rr->length = 0;
- goto start;
- }
- }
-
- /* We already handled these. */
- assert(rr->type != SSL3_RT_CHANGE_CIPHER_SPEC && rr->type != SSL3_RT_ALERT);
-
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
-
- f_err:
- ssl3_send_alert(s, SSL3_AL_FATAL, al);
- err:
- return -1;
- }
-
- int dtls1_write_app_data(SSL *s, const void *buf_, int len) {
- int i;
-
- if (SSL_in_init(s) && !s->in_handshake) {
- i = s->handshake_func(s);
- if (i < 0) {
- return i;
- }
- if (i == 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
- return -1;
- }
- }
-
- if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DTLS_MESSAGE_TOO_BIG);
- return -1;
- }
-
- i = dtls1_write_bytes(s, SSL3_RT_APPLICATION_DATA, buf_, len,
- dtls1_use_current_epoch);
- return i;
- }
-
- /* 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 *s, int type, const void *buf, int len,
- enum dtls1_use_epoch_t use_epoch) {
- int i;
-
- assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
- s->rwstate = SSL_NOTHING;
- i = do_dtls1_write(s, type, buf, len, use_epoch);
- return i;
- }
-
- /* dtls1_seal_record seals a new record of type |type| and plaintext |in| and
- * writes it to |out|. At most |max_out| bytes will be written. It returns one
- * on success and zero on error. On success, it updates the write sequence
- * number. */
- static int dtls1_seal_record(SSL *s, uint8_t *out, size_t *out_len,
- size_t max_out, uint8_t type, const uint8_t *in,
- size_t in_len, enum dtls1_use_epoch_t use_epoch) {
- if (max_out < DTLS1_RT_HEADER_LENGTH) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL);
- return 0;
- }
-
- /* Determine the parameters for the current epoch. */
- uint16_t epoch = s->d1->w_epoch;
- SSL_AEAD_CTX *aead = s->aead_write_ctx;
- uint8_t *seq = s->s3->write_sequence;
- if (use_epoch == dtls1_use_previous_epoch) {
- /* DTLS renegotiation is unsupported, so only epochs 0 (NULL cipher) and 1
- * (negotiated cipher) exist. */
- assert(s->d1->w_epoch == 1);
- epoch = s->d1->w_epoch - 1;
- aead = NULL;
- seq = s->d1->last_write_sequence;
- }
-
- out[0] = type;
-
- uint16_t wire_version = s->s3->have_version ? s->version : DTLS1_VERSION;
- out[1] = wire_version >> 8;
- out[2] = wire_version & 0xff;
-
- out[3] = epoch >> 8;
- out[4] = epoch & 0xff;
- memcpy(&out[5], &seq[2], 6);
-
- size_t ciphertext_len;
- if (!SSL_AEAD_CTX_seal(aead, out + DTLS1_RT_HEADER_LENGTH, &ciphertext_len,
- max_out - DTLS1_RT_HEADER_LENGTH, type, wire_version,
- &out[3] /* seq */, in, in_len) ||
- !ssl3_record_sequence_update(&seq[2], 6)) {
- return 0;
- }
-
- if (ciphertext_len >= 1 << 16) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
- return 0;
- }
- out[11] = ciphertext_len >> 8;
- out[12] = ciphertext_len & 0xff;
-
- *out_len = DTLS1_RT_HEADER_LENGTH + ciphertext_len;
-
- if (s->msg_callback) {
- s->msg_callback(1 /* write */, 0, SSL3_RT_HEADER, out,
- DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
- }
-
- return 1;
- }
-
- static int do_dtls1_write(SSL *s, int type, const uint8_t *buf,
- unsigned int len, enum dtls1_use_epoch_t use_epoch) {
- SSL3_BUFFER *wb = &s->s3->wbuf;
-
- /* ssl3_write_pending drops the write if |BIO_write| fails in DTLS, so there
- * is never pending data. */
- assert(s->s3->wbuf.left == 0);
-
- /* If we have an alert to send, lets send it */
- if (s->s3->alert_dispatch) {
- int ret = s->method->ssl_dispatch_alert(s);
- if (ret <= 0) {
- return ret;
- }
- /* if it went, fall through and send more stuff */
- }
-
- if (wb->buf == NULL && !ssl3_setup_write_buffer(s)) {
- return -1;
- }
-
- if (len == 0) {
- return 0;
- }
-
- /* Align the output so the ciphertext is aligned to |SSL3_ALIGN_PAYLOAD|. */
- uintptr_t align = (uintptr_t)wb->buf + DTLS1_RT_HEADER_LENGTH;
- align = (0 - align) & (SSL3_ALIGN_PAYLOAD - 1);
- uint8_t *out = wb->buf + align;
- wb->offset = align;
- size_t max_out = wb->len - wb->offset;
-
- size_t ciphertext_len;
- if (!dtls1_seal_record(s, out, &ciphertext_len, max_out, type, buf, len,
- use_epoch)) {
- return -1;
- }
-
- /* now let's set up wb */
- wb->left = ciphertext_len;
-
- /* memorize arguments so that ssl3_write_pending can detect bad write retries
- * later */
- s->s3->wpend_tot = len;
- s->s3->wpend_buf = buf;
- s->s3->wpend_type = type;
- s->s3->wpend_ret = len;
-
- /* we now just need to write the buffer */
- return ssl3_write_pending(s, type, buf, len);
- }
-
- static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) {
- int cmp;
- unsigned int shift;
- const uint8_t *seq = s->s3->read_sequence;
-
- cmp = satsub64be(seq, bitmap->max_seq_num);
- if (cmp > 0) {
- memcpy(s->s3->rrec.seq_num, seq, 8);
- return 1; /* this record in new */
- }
- shift = -cmp;
- if (shift >= sizeof(bitmap->map) * 8) {
- return 0; /* stale, outside the window */
- } else if (bitmap->map & (((uint64_t)1) << shift)) {
- return 0; /* record previously received */
- }
-
- memcpy(s->s3->rrec.seq_num, seq, 8);
- return 1;
- }
-
- static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) {
- int cmp;
- unsigned int shift;
- const uint8_t *seq = s->s3->read_sequence;
-
- cmp = satsub64be(seq, bitmap->max_seq_num);
- if (cmp > 0) {
- shift = cmp;
- if (shift < sizeof(bitmap->map) * 8) {
- bitmap->map <<= shift, bitmap->map |= 1UL;
- } else {
- bitmap->map = 1UL;
- }
- memcpy(bitmap->max_seq_num, seq, 8);
- } else {
- shift = -cmp;
- if (shift < sizeof(bitmap->map) * 8) {
- bitmap->map |= ((uint64_t)1) << shift;
- }
- }
- }
-
- int dtls1_dispatch_alert(SSL *s) {
- int i, j;
- void (*cb)(const SSL *ssl, int type, int val) = NULL;
- uint8_t buf[DTLS1_AL_HEADER_LENGTH];
- uint8_t *ptr = &buf[0];
-
- s->s3->alert_dispatch = 0;
-
- memset(buf, 0x00, sizeof(buf));
- *ptr++ = s->s3->send_alert[0];
- *ptr++ = s->s3->send_alert[1];
-
- i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf),
- dtls1_use_current_epoch);
- if (i <= 0) {
- s->s3->alert_dispatch = 1;
- } else {
- if (s->s3->send_alert[0] == SSL3_AL_FATAL) {
- (void)BIO_flush(s->wbio);
- }
-
- if (s->msg_callback) {
- s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s,
- s->msg_callback_arg);
- }
-
- if (s->info_callback != NULL) {
- cb = s->info_callback;
- } else if (s->ctx->info_callback != NULL) {
- cb = s->ctx->info_callback;
- }
-
- if (cb != NULL) {
- j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1];
- cb(s, SSL_CB_WRITE_ALERT, j);
- }
- }
-
- return i;
- }
-
- void dtls1_reset_seq_numbers(SSL *s, int rw) {
- uint8_t *seq;
- unsigned int seq_bytes = sizeof(s->s3->read_sequence);
-
- if (rw & SSL3_CC_READ) {
- seq = s->s3->read_sequence;
- s->d1->r_epoch++;
- memset(&s->d1->bitmap, 0, sizeof(DTLS1_BITMAP));
- } else {
- seq = s->s3->write_sequence;
- memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
- s->d1->w_epoch++;
- }
-
- memset(seq, 0x00, seq_bytes);
- }
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