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boringssl / boringssl / dc4b197f0f7281da024a970a78892b1f09f0a8db / . / ssl / d1_pkt.c
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/* 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 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;
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;
enc_err = s->enc_method->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;
}
/* 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 */
uint8_t *mac = NULL;
uint8_t mac_tmp[EVP_MAX_MD_SIZE];
mac_size = EVP_MD_CTX_size(s->read_hash);
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;
OPENSSL_PUT_ERROR(SSL, 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->enc_method->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;
}
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->enc_read_ctx == NULL)) {
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, mac_size = 0;
int prefix_len = 0;
int eivlen = 0;
SSL3_RECORD *wr;
SSL3_BUFFER *wb;
SSL_SESSION *sess;
/* 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);
sess = s->session;
if (sess != NULL && s->enc_write_ctx != NULL &&
EVP_MD_CTX_md(s->write_hash) != NULL) {
mac_size = EVP_MD_CTX_size(s->write_hash);
if (mac_size < 0) {
goto err;
}
}
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;
/* Explicit IV length, block ciphers appropriate version flag */
if (s->enc_write_ctx) {
int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
if (mode == EVP_CIPH_CBC_MODE) {
eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
if (eivlen <= 1) {
eivlen = 0;
}
} else if (mode == EVP_CIPH_GCM_MODE) {
/* Need explicit part of IV for GCM mode */
eivlen = EVP_GCM_TLS_EXPLICIT_IV_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;
/* we should still have the output to wr->data and the input from wr->input.
* Length should be wr->length. wr->data still points in the wb->buf */
if (mac_size != 0) {
if (s->enc_method->mac(s, &(p[wr->length + eivlen]), 1) < 0) {
goto err;
}
wr->length += mac_size;
}
/* this is true regardless of mac size */
wr->input = p;
wr->data = p;
wr->length += eivlen;
if (s->enc_method->enc(s, 1) < 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);
}