|
- /* 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 <stdio.h>
- #include <errno.h>
- #include <assert.h>
-
- #include <openssl/buf.h>
- #include <openssl/mem.h>
- #include <openssl/evp.h>
- #include <openssl/err.h>
- #include <openssl/rand.h>
-
- #include "ssl_locl.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 have_handshake_fragment(SSL *s, int type, uint8_t *buf, int len,
- int peek);
- static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
- static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
- static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
- unsigned int *is_next_epoch);
- static int dtls1_buffer_record(SSL *s, record_pqueue *q,
- uint8_t *priority);
- static int dtls1_process_record(SSL *s);
- static int do_dtls1_write(SSL *s, int type, const uint8_t *buf,
- unsigned int len);
-
- /* copy buffered record into SSL structure */
- static int dtls1_copy_record(SSL *s, pitem *item) {
- DTLS1_RECORD_DATA *rdata;
-
- rdata = (DTLS1_RECORD_DATA *)item->data;
-
- if (s->s3->rbuf.buf != NULL) {
- OPENSSL_free(s->s3->rbuf.buf);
- }
-
- s->packet = rdata->packet;
- s->packet_length = rdata->packet_length;
- memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
- memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
-
- /* Set proper sequence number for mac calculation */
- memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
-
- return 1;
- }
-
- static int dtls1_buffer_record(SSL *s, record_pqueue *queue,
- uint8_t *priority) {
- DTLS1_RECORD_DATA *rdata;
- pitem *item;
-
- /* Limit the size of the queue to prevent DOS attacks */
- if (pqueue_size(queue->q) >= 100) {
- return 0;
- }
-
- rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
- item = pitem_new(priority, rdata);
- if (rdata == NULL || item == NULL) {
- if (rdata != NULL) {
- OPENSSL_free(rdata);
- }
- if (item != NULL) {
- pitem_free(item);
- }
-
- OPENSSL_PUT_ERROR(SSL, dtls1_buffer_record, ERR_R_INTERNAL_ERROR);
- return -1;
- }
-
- rdata->packet = s->packet;
- rdata->packet_length = s->packet_length;
- memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
- memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
-
- item->data = rdata;
-
- s->packet = NULL;
- s->packet_length = 0;
- memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
- memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
-
- if (!ssl3_setup_buffers(s)) {
- goto internal_error;
- }
-
- /* insert should not fail, since duplicates are dropped */
- if (pqueue_insert(queue->q, item) == NULL) {
- goto internal_error;
- }
-
- return 1;
-
- internal_error:
- OPENSSL_PUT_ERROR(SSL, dtls1_buffer_record, ERR_R_INTERNAL_ERROR);
- if (rdata->rbuf.buf != NULL) {
- OPENSSL_free(rdata->rbuf.buf);
- }
- OPENSSL_free(rdata);
- pitem_free(item);
- return -1;
- }
-
- static int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) {
- pitem *item;
-
- item = pqueue_pop(queue->q);
- if (item) {
- dtls1_copy_record(s, item);
-
- OPENSSL_free(item->data);
- pitem_free(item);
-
- return 1;
- }
-
- return 0;
- }
-
- /* retrieve a buffered record that belongs to the new epoch, i.e., not
- * processed yet */
- #define dtls1_get_unprocessed_record(s) \
- dtls1_retrieve_buffered_record((s), &((s)->d1->unprocessed_rcds))
-
- /* retrieve a buffered record that belongs to the current epoch, i.e.,
- * processed */
- #define dtls1_get_processed_record(s) \
- dtls1_retrieve_buffered_record((s), &((s)->d1->processed_rcds))
-
- static int dtls1_process_buffered_records(SSL *s) {
- pitem *item;
-
- item = pqueue_peek(s->d1->unprocessed_rcds.q);
- if (item) {
- /* Check if epoch is current. */
- if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) {
- return 1; /* Nothing to do. */
- }
-
- /* Process all the records. */
- while (pqueue_peek(s->d1->unprocessed_rcds.q)) {
- dtls1_get_unprocessed_record(s);
- if (!dtls1_process_record(s)) {
- return 0;
- }
- if (dtls1_buffer_record(s, &(s->d1->processed_rcds),
- s->s3->rrec.seq_num) < 0) {
- return -1;
- }
- }
- }
-
- /* sync epoch numbers once all the unprocessed records have been processed */
- s->d1->processed_rcds.epoch = s->d1->r_epoch;
- s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
-
- return 1;
- }
-
- static int dtls1_process_record(SSL *s) {
- int al;
- SSL3_RECORD *rr;
-
- rr = &(s->s3->rrec);
-
- /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, and
- * we have that many bytes in s->packet. */
- rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]);
-
- /* ok, we can now read from 's->packet' data into 'rr' rr->input points at
- * rr->length bytes, which need to be copied into rr->data by either the
- * decryption or by the decompression When the data is 'copied' into the
- * rr->data buffer, rr->input will be pointed at the new buffer */
-
- /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length bytes
- * of encrypted compressed stuff. */
-
- /* check is not needed I believe */
- if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
- al = SSL_AD_RECORD_OVERFLOW;
- OPENSSL_PUT_ERROR(SSL, dtls1_process_record,
- SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
- goto f_err;
- }
-
- /* decrypt in place in 'rr->input' */
- rr->data = rr->input;
-
- if (!s->enc_method->enc(s, 0)) {
- /* 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 (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
- al = SSL_AD_RECORD_OVERFLOW;
- OPENSSL_PUT_ERROR(SSL, dtls1_process_record, SSL_R_DATA_LENGTH_TOO_LONG);
- goto f_err;
- }
-
- 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 == where to take bytes from, increment
- * after use :-). */
-
- /* 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) {
- int ssl_major, ssl_minor;
- int i, n;
- SSL3_RECORD *rr;
- unsigned char *p = NULL;
- unsigned short version;
- DTLS1_BITMAP *bitmap;
- unsigned int is_next_epoch;
-
- rr = &(s->s3->rrec);
-
- /* The epoch may have changed. If so, process all the pending records. This
- * is a non-blocking operation. */
- if (dtls1_process_buffered_records(s) < 0) {
- return -1;
- }
-
- /* If we're renegotiating, then there may be buffered records. */
- if (dtls1_get_processed_record(s)) {
- return 1;
- }
-
- /* 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, s->s3->rbuf.len, 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 = (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 */
- i = rr->length;
- n = ssl3_read_n(s, i, i, 1);
- if (n <= 0) {
- return n; /* error or non-blocking io */
- }
-
- /* this packet contained a partial record, dump it */
- if (n != i) {
- 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 */
-
- /* match epochs. NULL means the packet is dropped on the floor */
- bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
- if (bitmap == NULL) {
- rr->length = 0;
- s->packet_length = 0; /* dump this record */
- goto again; /* get another record */
- }
-
- /* Check whether this is a repeat, or aged record. */
- if (!dtls1_record_replay_check(s, 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 this record is from the next epoch (either HM or ALERT),
- * and a handshake is currently in progress, buffer it since it
- * cannot be processed at this time.
- */
- if (is_next_epoch) {
- if (SSL_in_init(s) || s->in_handshake) {
- if (dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num) < 0) {
- return -1;
- }
- dtls1_record_bitmap_update(s, bitmap); /* Mark receipt of record. */
- }
- rr->length = 0;
- s->packet_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, bitmap); /* Mark receipt of record. */
-
- return 1;
- }
-
- /* 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, j, ret;
- unsigned int n;
- SSL3_RECORD *rr;
- void (*cb)(const SSL *ssl, int type2, int val) = NULL;
-
- if (s->s3->rbuf.buf == NULL && !ssl3_setup_buffers(s)) {
- return -1;
- }
-
- /* 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, dtls1_read_bytes, ERR_R_INTERNAL_ERROR);
- return -1;
- }
-
- /* check whether there's a handshake message (client hello?) waiting */
- ret = have_handshake_fragment(s, type, buf, len, peek);
- if (ret) {
- return ret;
- }
-
- /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
-
- 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, dtls1_read_bytes, 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;
-
- /* We are not handshaking and have no data yet,
- * so process data buffered during the last handshake
- * in advance, if any.
- */
- if (s->state == SSL_ST_OK && rr->length == 0) {
- pitem *item;
- item = pqueue_pop(s->d1->buffered_app_data.q);
- if (item) {
- dtls1_copy_record(s, item);
-
- OPENSSL_free(item->data);
- pitem_free(item);
- }
- }
-
- /* Check for timeout */
- if (dtls1_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) {
- /* We now have application data between CCS and Finished. Most likely the
- * packets were reordered on their way, so buffer the application data for
- * later processing rather than dropping the connection. */
- if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) < 0) {
- OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, ERR_R_INTERNAL_ERROR);
- return -1;
- }
- 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, dtls1_read_bytes, 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 we have a handshake message,
- * then it was unexpected (Hello Request or Client Hello). */
-
- /* In case of record types for which we have 'fragment' storage, fill that so
- * that we can process the data at a fixed place. */
- {
- unsigned int k, dest_maxlen = 0;
- uint8_t *dest = NULL;
- unsigned int *dest_len = NULL;
-
- if (rr->type == SSL3_RT_HANDSHAKE) {
- dest_maxlen = sizeof s->d1->handshake_fragment;
- dest = s->d1->handshake_fragment;
- dest_len = &s->d1->handshake_fragment_len;
- } else if (rr->type == SSL3_RT_ALERT) {
- dest_maxlen = sizeof(s->d1->alert_fragment);
- dest = s->d1->alert_fragment;
- dest_len = &s->d1->alert_fragment_len;
- }
- /* else it's a CCS message, or application data or wrong */
- else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
- /* Application data while renegotiating is allowed. Try again reading. */
- if (rr->type == SSL3_RT_APPLICATION_DATA) {
- BIO *bio;
- s->s3->in_read_app_data = 2;
- bio = SSL_get_rbio(s);
- s->rwstate = SSL_READING;
- BIO_clear_retry_flags(bio);
- BIO_set_retry_read(bio);
- return -1;
- }
-
- /* Not certain if this is the right error handling */
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNEXPECTED_RECORD);
- goto f_err;
- }
-
- if (dest_maxlen > 0) {
- /* XDTLS: In a pathalogical case, the Client Hello
- * may be fragmented--don't always expect dest_maxlen bytes */
- if (rr->length < dest_maxlen) {
- s->rstate = SSL_ST_READ_HEADER;
- rr->length = 0;
- goto start;
- }
-
- /* now move 'n' bytes: */
- for (k = 0; k < dest_maxlen; k++) {
- dest[k] = rr->data[rr->off++];
- rr->length--;
- }
- *dest_len = dest_maxlen;
- }
- }
-
- /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
- * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
- * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
-
- /* If we are a client, check for an incoming 'Hello Request': */
- if (!s->server && s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH &&
- s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST &&
- s->session != NULL && s->session->cipher != NULL) {
- s->d1->handshake_fragment_len = 0;
-
- if ((s->d1->handshake_fragment[1] != 0) ||
- (s->d1->handshake_fragment[2] != 0) ||
- (s->d1->handshake_fragment[3] != 0)) {
- al = SSL_AD_DECODE_ERROR;
- OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_BAD_HELLO_REQUEST);
- goto f_err;
- }
-
- /* no need to check sequence number on HELLO REQUEST messages */
-
- if (s->msg_callback) {
- s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
- s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
- }
-
- if (SSL_is_init_finished(s) && !s->s3->renegotiate) {
- s->d1->handshake_read_seq++;
- s->new_session = 1;
- ssl3_renegotiate(s);
- if (ssl3_renegotiate_check(s)) {
- i = s->handshake_func(s);
- if (i < 0) {
- return i;
- }
- if (i == 0) {
- OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_SSL_HANDSHAKE_FAILURE);
- return -1;
- }
- }
- }
-
- /* we either finished a handshake or ignored the request, now try again to
- * obtain the (application) data we were asked for */
- goto start;
- }
-
- if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
- int alert_level = s->d1->alert_fragment[0];
- int alert_descr = s->d1->alert_fragment[1];
-
- s->d1->alert_fragment_len = 0;
-
- if (s->msg_callback) {
- s->msg_callback(0, s->version, SSL3_RT_ALERT, s->d1->alert_fragment, 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 = (alert_level << 8) | alert_descr;
- cb(s, SSL_CB_READ_ALERT, j);
- }
-
- if (alert_level == 1) { /* 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 == 2) { /* fatal */
- char tmp[16];
-
- s->rwstate = SSL_NOTHING;
- s->s3->fatal_alert = alert_descr;
- OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes,
- 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, dtls1_read_bytes, 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) {
- struct ccs_header_st ccs_hdr;
- unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
-
- dtls1_get_ccs_header(rr->data, &ccs_hdr);
-
- /* 'Change Cipher Spec' is just a single byte, so we know
- * exactly what the record payload has to look like */
- /* XDTLS: check that epoch is consistent */
- if ((rr->length != ccs_hdr_len) || (rr->off != 0) ||
- (rr->data[0] != SSL3_MT_CCS)) {
- al = SSL_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, 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 (Client Hello, or protocol violation) */
- if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
- !s->in_handshake) {
- struct hm_header_st msg_hdr;
-
- /* this may just be a stale retransmit */
- dtls1_get_message_header(rr->data, &msg_hdr);
- if (rr->epoch != s->d1->r_epoch) {
- rr->length = 0;
- goto start;
- }
-
- /* If we are server, we may have a repeated FINISHED of the client here,
- * then retransmit our CCS and FINISHED. */
- if (msg_hdr.type == SSL3_MT_FINISHED) {
- if (dtls1_check_timeout_num(s) < 0) {
- return -1;
- }
-
- dtls1_retransmit_buffered_messages(s);
- rr->length = 0;
- goto start;
- }
-
- if ((s->state & SSL_ST_MASK) == SSL_ST_OK) {
- s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
- s->renegotiate = 1;
- s->new_session = 1;
- }
- i = s->handshake_func(s);
- if (i < 0) {
- return i;
- }
- if (i == 0) {
- OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_SSL_HANDSHAKE_FAILURE);
- return -1;
- }
-
- goto start;
- }
-
- switch (rr->type) {
- default:
- /* TLS just ignores unknown message types */
- if (s->version == TLS1_VERSION) {
- rr->length = 0;
- goto start;
- }
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNEXPECTED_RECORD);
- goto f_err;
-
- case SSL3_RT_CHANGE_CIPHER_SPEC:
- case SSL3_RT_ALERT:
- case SSL3_RT_HANDSHAKE:
- /* we already handled all of these, with the possible exception of
- * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
- * happen when type != rr->type */
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, ERR_R_INTERNAL_ERROR);
- goto f_err;
-
- case SSL3_RT_APPLICATION_DATA:
- /* At this point, we were expecting handshake data, but have application
- * data. If the library was running inside ssl3_read() (i.e.
- * in_read_app_data is set) and it makes sense to read application data
- * at this point (session renegotiation not yet started), we will indulge
- * it. */
- if (s->s3->in_read_app_data && (s->s3->total_renegotiations != 0) &&
- (((s->state & SSL_ST_CONNECT) &&
- (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
- (s->state <= SSL3_ST_CR_SRVR_HELLO_A)) ||
- ((s->state & SSL_ST_ACCEPT) &&
- (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
- (s->state >= SSL3_ST_SR_CLNT_HELLO_A)))) {
- s->s3->in_read_app_data = 2;
- return -1;
- } else {
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNEXPECTED_RECORD);
- goto f_err;
- }
- }
-
- /* not reached */
-
- f_err:
- ssl3_send_alert(s, SSL3_AL_FATAL, al);
- err:
- return -1;
- }
-
- int dtls1_write_app_data_bytes(SSL *s, int type, 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, dtls1_write_app_data_bytes,
- SSL_R_SSL_HANDSHAKE_FAILURE);
- return -1;
- }
- }
-
- if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
- OPENSSL_PUT_ERROR(SSL, dtls1_write_app_data_bytes,
- SSL_R_DTLS_MESSAGE_TOO_BIG);
- return -1;
- }
-
- i = dtls1_write_bytes(s, type, buf_, len);
- return i;
- }
-
-
- /* this only happens when a client hello is received and a handshake is
- * started. */
- static int have_handshake_fragment(SSL *s, int type, uint8_t *buf,
- int len, int peek) {
- if (type == SSL3_RT_HANDSHAKE && s->d1->handshake_fragment_len > 0) {
- /* (partially) satisfy request from storage */
- uint8_t *src = s->d1->handshake_fragment;
- uint8_t *dst = buf;
- unsigned int k, n;
-
- /* peek == 0 */
- n = 0;
- while (len > 0 && s->d1->handshake_fragment_len > 0) {
- *dst++ = *src++;
- len--;
- s->d1->handshake_fragment_len--;
- n++;
- }
- /* move any remaining fragment bytes: */
- for (k = 0; k < s->d1->handshake_fragment_len; k++) {
- s->d1->handshake_fragment[k] = *src++;
- }
- return n;
- }
-
- return 0;
- }
-
- /* 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) {
- int i;
-
- assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
- s->rwstate = SSL_NOTHING;
- i = do_dtls1_write(s, type, buf, len);
- return i;
- }
-
- static int do_dtls1_write(SSL *s, int type, const uint8_t *buf,
- unsigned int len) {
- uint8_t *p, *pseq;
- int i;
- int prefix_len = 0;
- int eivlen = 0;
- SSL3_RECORD *wr;
- SSL3_BUFFER *wb;
-
- /* first check if there is a SSL3_BUFFER still being written
- * out. This will happen with non blocking IO */
- if (s->s3->wbuf.left != 0) {
- assert(0); /* XDTLS: want to see if we ever get here */
- return ssl3_write_pending(s, type, buf, len);
- }
-
- /* If we have an alert to send, lets send it */
- if (s->s3->alert_dispatch) {
- i = s->method->ssl_dispatch_alert(s);
- if (i <= 0) {
- return i;
- }
- /* if it went, fall through and send more stuff */
- }
-
- if (len == 0) {
- return 0;
- }
-
- wr = &(s->s3->wrec);
- wb = &(s->s3->wbuf);
-
- p = wb->buf + prefix_len;
-
- /* write the header */
-
- *(p++) = type & 0xff;
- wr->type = type;
- /* Special case: for hello verify request, client version 1.0 and
- * we haven't decided which version to use yet send back using
- * version 1.0 header: otherwise some clients will ignore it.
- */
- if (!s->s3->have_version) {
- *(p++) = DTLS1_VERSION >> 8;
- *(p++) = DTLS1_VERSION & 0xff;
- } else {
- *(p++) = s->version >> 8;
- *(p++) = s->version & 0xff;
- }
-
- /* field where we are to write out packet epoch, seq num and len */
- pseq = p;
- p += 10;
-
- /* Leave room for the variable nonce for AEADs which specify it explicitly. */
- if (s->aead_write_ctx != NULL &&
- s->aead_write_ctx->variable_nonce_included_in_record) {
- eivlen = s->aead_write_ctx->variable_nonce_len;
- }
-
- /* lets setup the record stuff. */
- wr->data = p + eivlen; /* make room for IV in case of CBC */
- wr->length = (int)len;
- wr->input = (unsigned char *)buf;
-
- /* we now 'read' from wr->input, wr->length bytes into wr->data */
- memcpy(wr->data, wr->input, wr->length);
- wr->input = wr->data;
-
- /* this is true regardless of mac size */
- wr->input = p;
- wr->data = p;
- wr->length += eivlen;
-
- if (!s->enc_method->enc(s, 1)) {
- goto err;
- }
-
- /* there's only one epoch between handshake and app data */
- s2n(s->d1->w_epoch, pseq);
-
- memcpy(pseq, &(s->s3->write_sequence[2]), 6);
- pseq += 6;
- s2n(wr->length, pseq);
-
- if (s->msg_callback) {
- s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
- DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
- }
-
- /* we should now have wr->data pointing to the encrypted data, which is
- * wr->length long */
- wr->type = type; /* not needed but helps for debugging */
- wr->length += DTLS1_RT_HEADER_LENGTH;
-
- ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
-
- /* now let's set up wb */
- wb->left = prefix_len + wr->length;
- wb->offset = 0;
-
- /* 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);
-
- err:
- return -1;
- }
-
- 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));
- 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;
- }
-
- static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
- unsigned int *is_next_epoch) {
- *is_next_epoch = 0;
-
- /* In current epoch, accept HM, CCS, DATA, & ALERT */
- if (rr->epoch == s->d1->r_epoch) {
- return &s->d1->bitmap;
- } else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
- (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
- /* Only HM and ALERT messages can be from the next epoch */
- *is_next_epoch = 1;
- return &s->d1->next_bitmap;
- }
-
- return NULL;
- }
-
- 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++;
- memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
- memset(&(s->d1->next_bitmap), 0x00, 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);
- }
|