/
d1_pkt.c
1961 lines (1720 loc) · 62.9 KB
/
d1_pkt.c
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/* ssl/d1_pkt.c */
/*
* 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>
#define USE_SOCKETS
#include "ssl_locl.h"
#include <openssl/evp.h>
#include <openssl/buffer.h>
#include <openssl/pqueue.h>
#include <openssl/rand.h>
/* mod 128 saturating subtract of two 64-bit values in big-endian order */
static int satsub64be(const unsigned char *v1, const unsigned char *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, unsigned char *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);
#if 0
static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
unsigned short *priority,
unsigned long *offset);
#endif
static int dtls1_buffer_record(SSL *s, record_pqueue *q,
unsigned char *priority);
static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap);
/* 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, unsigned char *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);
SSLerr(SSL_F_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;
#ifndef OPENSSL_NO_SCTP
/* Store bio_dgram_sctp_rcvinfo struct */
if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
(s->state == SSL3_ST_SR_FINISHED_A
|| s->state == SSL3_ST_CR_FINISHED_A)) {
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
sizeof(rdata->recordinfo), &rdata->recordinfo);
}
#endif
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)) {
SSLerr(SSL_F_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);
}
/* insert should not fail, since duplicates are dropped */
if (pqueue_insert(queue->q, item) == NULL) {
SSLerr(SSL_F_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);
}
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, ie,
* 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;
SSL3_BUFFER *rb;
SSL3_RECORD *rr;
DTLS1_BITMAP *bitmap;
unsigned int is_next_epoch;
int replayok = 1;
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. */
rr = &s->s3->rrec;
rb = &s->s3->rbuf;
if (rb->left > 0) {
/*
* We've still got data from the current packet to read. There could
* be a record from the new epoch in it - so don't overwrite it
* with the unprocessed records yet (we'll do it when we've
* finished reading the current packet).
*/
return 1;
}
/* Process all the records. */
while (pqueue_peek(s->d1->unprocessed_rcds.q)) {
dtls1_get_unprocessed_record(s);
bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
if (bitmap == NULL) {
/*
* Should not happen. This will only ever be NULL when the
* current record is from a different epoch. But that cannot
* be the case because we already checked the epoch above
*/
SSLerr(SSL_F_DTLS1_PROCESS_BUFFERED_RECORDS,
ERR_R_INTERNAL_ERROR);
return 0;
}
#ifndef OPENSSL_NO_SCTP
/* Only do replay check if no SCTP bio */
if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
#endif
{
/*
* Check whether this is a repeat, or aged record. We did this
* check once already when we first received the record - but
* we might have updated the window since then due to
* records we subsequently processed.
*/
replayok = dtls1_record_replay_check(s, bitmap);
}
if (!replayok || !dtls1_process_record(s, bitmap)) {
/* dump this record */
rr->length = 0;
s->packet_length = 0;
continue;
}
if (dtls1_buffer_record(s, &(s->d1->processed_rcds),
s->s3->rrec.seq_num) < 0)
return 0;
}
}
/*
* 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;
}
#if 0
static int dtls1_get_buffered_record(SSL *s)
{
pitem *item;
PQ_64BIT priority =
(((PQ_64BIT) s->d1->handshake_read_seq) << 32) |
((PQ_64BIT) s->d1->r_msg_hdr.frag_off);
/* if we're not (re)negotiating, nothing buffered */
if (!SSL_in_init(s))
return 0;
item = pqueue_peek(s->d1->rcvd_records);
if (item && item->priority == priority) {
/*
* Check if we've received the record of interest. It must be a
* handshake record, since data records as passed up without
* buffering
*/
DTLS1_RECORD_DATA *rdata;
item = pqueue_pop(s->d1->rcvd_records);
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));
OPENSSL_free(item->data);
pitem_free(item);
/* s->d1->next_expected_seq_num++; */
return (1);
}
return 0;
}
#endif
static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
{
int i, al;
int enc_err;
SSL_SESSION *sess;
SSL3_RECORD *rr;
unsigned int mac_size, orig_len;
unsigned char md[EVP_MAX_MD_SIZE];
rr = &(s->s3->rrec);
sess = s->session;
/*
* 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;
SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
goto f_err;
}
/* decrypt in place in 'rr->input' */
rr->data = rr->input;
enc_err = s->method->ssl3_enc->enc(s, 0);
/*-
* enc_err is:
* 0: (in non-constant time) if the record is publically invalid.
* 1: if the padding is valid
* -1: if the padding is invalid
*/
if (enc_err == 0) {
/* For DTLS we simply ignore bad packets. */
rr->length = 0;
s->packet_length = 0;
goto err;
}
#ifdef TLS_DEBUG
printf("dec %d\n", rr->length);
{
unsigned int z;
for (z = 0; z < rr->length; z++)
printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
}
printf("\n");
#endif
/* r->length is now the compressed data plus mac */
if ((sess != NULL) &&
(s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
/* s->read_hash != NULL => mac_size != -1 */
unsigned char *mac = NULL;
unsigned char mac_tmp[EVP_MAX_MD_SIZE];
mac_size = EVP_MD_CTX_size(s->read_hash);
OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
/*
* kludge: *_cbc_remove_padding passes padding length in rr->type
*/
orig_len = rr->length + ((unsigned int)rr->type >> 8);
/*
* orig_len is the length of the record before any padding was
* removed. This is public information, as is the MAC in use,
* therefore we can safely process the record in a different amount
* of time if it's too short to possibly contain a MAC.
*/
if (orig_len < mac_size ||
/* CBC records must have a padding length byte too. */
(EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
orig_len < mac_size + 1)) {
al = SSL_AD_DECODE_ERROR;
SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
goto f_err;
}
if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
/*
* We update the length so that the TLS header bytes can be
* constructed correctly but we need to extract the MAC in
* constant time from within the record, without leaking the
* contents of the padding bytes.
*/
mac = mac_tmp;
ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
rr->length -= mac_size;
} else {
/*
* In this case there's no padding, so |orig_len| equals
* |rec->length| and we checked that there's enough bytes for
* |mac_size| above.
*/
rr->length -= mac_size;
mac = &rr->data[rr->length];
}
i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
if (i < 0 || mac == NULL
|| CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
enc_err = -1;
if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
enc_err = -1;
}
if (enc_err < 0) {
/* decryption failed, silently discard message */
rr->length = 0;
s->packet_length = 0;
goto err;
}
/* r->length is now just compressed */
if (s->expand != NULL) {
if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
al = SSL_AD_RECORD_OVERFLOW;
SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
SSL_R_COMPRESSED_LENGTH_TOO_LONG);
goto f_err;
}
if (!ssl3_do_uncompress(s)) {
al = SSL_AD_DECOMPRESSION_FAILURE;
SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
goto f_err;
}
}
if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
al = SSL_AD_RECORD_OVERFLOW;
SSLerr(SSL_F_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;
/* Mark receipt of record. */
dtls1_record_bitmap_update(s, bitmap);
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);
again:
/*
* The epoch may have changed. If so, process all the pending records.
* This is a non-blocking operation.
*/
if (!dtls1_process_buffered_records(s))
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 */
/* 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;
/* 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->first_packet) {
if (version != s->version) {
/* unexpected version, silently discard */
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);
/* 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 */
}
#ifndef OPENSSL_NO_SCTP
/* Only do replay check if no SCTP bio */
if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
#endif
/*
* Check whether this is a repeat, or aged record. Don't check if
* we're listening and this message is a ClientHello. They can look
* as if they're replayed, since they arrive from different
* connections and would be dropped unnecessarily.
*/
if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
s->packet_length > DTLS1_RT_HEADER_LENGTH &&
s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) &&
!dtls1_record_replay_check(s, bitmap)) {
rr->length = 0;
s->packet_length = 0; /* dump this record */
goto again; /* get another record */
}
#ifndef OPENSSL_NO_SCTP
}
#endif
/* 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. However, do not buffer anything while
* listening.
*/
if (is_next_epoch) {
if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) {
if (dtls1_buffer_record
(s, &(s->d1->unprocessed_rcds), rr->seq_num) < 0)
return -1;
}
rr->length = 0;
s->packet_length = 0;
goto again;
}
if (!dtls1_process_record(s, bitmap)) {
rr->length = 0;
s->packet_length = 0; /* dump this record */
goto again; /* get another 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) /* Not initialized yet */
if (!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))) {
SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
return -1;
}
/*
* check whether there's a handshake message (client hello?) waiting
*/
if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
return ret;
/*
* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE.
*/
#ifndef OPENSSL_NO_SCTP
/*
* Continue handshake if it had to be interrupted to read app data with
* SCTP.
*/
if ((!s->in_handshake && SSL_in_init(s)) ||
(BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
(s->state == DTLS1_SCTP_ST_SR_READ_SOCK
|| s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
&& s->s3->in_read_app_data != 2))
#else
if (!s->in_handshake && SSL_in_init(s))
#endif
{
/* type == SSL3_RT_APPLICATION_DATA */
i = s->handshake_func(s);
if (i < 0)
return (i);
if (i == 0) {
SSLerr(SSL_F_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) {
#ifndef OPENSSL_NO_SCTP
/* Restore bio_dgram_sctp_rcvinfo struct */
if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
sizeof(rdata->recordinfo), &rdata->recordinfo);
}
#endif
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;
}
}
if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
rr->length = 0;
goto start;
}
/* we now have a packet which can be read and processed */
if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
* reset by ssl3_get_finished */
&& (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) {
SSLerr(SSL_F_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->enc_read_ctx == NULL)) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_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;
}
}
#ifndef OPENSSL_NO_SCTP
/*
* We were about to renegotiate but had to read belated application
* data first, so retry.
*/
if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
rr->type == SSL3_RT_APPLICATION_DATA &&
(s->state == DTLS1_SCTP_ST_SR_READ_SOCK
|| s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
s->rwstate = SSL_READING;
BIO_clear_retry_flags(SSL_get_rbio(s));
BIO_set_retry_read(SSL_get_rbio(s));
}
/*