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pineapple-src/externals/libressl/ssl/d1_pkt.c

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early-access version 1255
2020-12-28 16:15:37 +01:00
/* $OpenBSD: d1_pkt.c,v 1.82 2020/09/24 17:59:54 jsing Exp $ */
/*
* 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 <machine/endian.h>
#include <errno.h>
#include <stdio.h>
#include "ssl_locl.h"
#include <openssl/buffer.h>
#include <openssl/evp.h>
#include "pqueue.h"
#include "bytestring.h"
static int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
unsigned int len);
/* 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 {
long l;
if (BYTE_ORDER == LITTLE_ENDIAN)
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_INTERNAL *rr,
unsigned int *is_next_epoch);
static int dtls1_buffer_record(SSL *s, record_pqueue *q,
unsigned char *priority);
static int dtls1_process_record(SSL *s);
/* copy buffered record into SSL structure */
static int
dtls1_copy_record(SSL *s, pitem *item)
{
DTLS1_RECORD_DATA_INTERNAL *rdata;
rdata = (DTLS1_RECORD_DATA_INTERNAL *)item->data;
ssl3_release_buffer(&S3I(s)->rbuf);
s->internal->packet = rdata->packet;
s->internal->packet_length = rdata->packet_length;
memcpy(&(S3I(s)->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER_INTERNAL));
memcpy(&(S3I(s)->rrec), &(rdata->rrec), sizeof(SSL3_RECORD_INTERNAL));
/* Set proper sequence number for mac calculation */
memcpy(&(S3I(s)->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_INTERNAL *rdata;
pitem *item;
/* Limit the size of the queue to prevent DOS attacks */
if (pqueue_size(queue->q) >= 100)
return 0;
rdata = malloc(sizeof(DTLS1_RECORD_DATA_INTERNAL));
item = pitem_new(priority, rdata);
if (rdata == NULL || item == NULL)
goto init_err;
rdata->packet = s->internal->packet;
rdata->packet_length = s->internal->packet_length;
memcpy(&(rdata->rbuf), &(S3I(s)->rbuf), sizeof(SSL3_BUFFER_INTERNAL));
memcpy(&(rdata->rrec), &(S3I(s)->rrec), sizeof(SSL3_RECORD_INTERNAL));
item->data = rdata;
s->internal->packet = NULL;
s->internal->packet_length = 0;
memset(&(S3I(s)->rbuf), 0, sizeof(SSL3_BUFFER_INTERNAL));
memset(&(S3I(s)->rrec), 0, sizeof(SSL3_RECORD_INTERNAL));
if (!ssl3_setup_buffers(s))
goto err;
/* insert should not fail, since duplicates are dropped */
if (pqueue_insert(queue->q, item) == NULL)
goto err;
return (1);
err:
ssl3_release_buffer(&rdata->rbuf);
init_err:
SSLerror(s, ERR_R_INTERNAL_ERROR);
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);
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), \
&((D1I(s))->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), \
&((D1I(s))->processed_rcds))
static int
dtls1_process_buffered_records(SSL *s)
{
pitem *item;
item = pqueue_peek(D1I(s)->unprocessed_rcds.q);
if (item) {
/* Check if epoch is current. */
if (D1I(s)->unprocessed_rcds.epoch != D1I(s)->r_epoch)
return (1);
/* Nothing to do. */
/* Process all the records. */
while (pqueue_peek(D1I(s)->unprocessed_rcds.q)) {
dtls1_get_unprocessed_record(s);
if (! dtls1_process_record(s))
return (0);
if (dtls1_buffer_record(s, &(D1I(s)->processed_rcds),
S3I(s)->rrec.seq_num) < 0)
return (-1);
}
}
/* sync epoch numbers once all the unprocessed records
* have been processed */
D1I(s)->processed_rcds.epoch = D1I(s)->r_epoch;
D1I(s)->unprocessed_rcds.epoch = D1I(s)->r_epoch + 1;
return (1);
}
static int
dtls1_process_record(SSL *s)
{
int i, al;
int enc_err;
SSL_SESSION *sess;
SSL3_RECORD_INTERNAL *rr;
unsigned int mac_size, orig_len;
unsigned char md[EVP_MAX_MD_SIZE];
rr = &(S3I(s)->rrec);
sess = s->session;
/* At this point, s->internal->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
* and we have that many bytes in s->internal->packet
*/
rr->input = &(s->internal->packet[DTLS1_RT_HEADER_LENGTH]);
/* ok, we can now read from 's->internal->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;
SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
goto f_err;
}
/* decrypt in place in 'rr->input' */
rr->data = rr->input;
/* 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 = tls1_enc(s, 0)) == 0) {
/* For DTLS we simply ignore bad packets. */
rr->length = 0;
s->internal->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 */
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);
orig_len = rr->length + rr->padding_length;
/* 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;
SSLerror(s, 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 = tls1_mac(s, md, 0 /* not send */);
if (i < 0 || mac == NULL || timingsafe_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->internal->packet_length = 0;
goto err;
}
if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
al = SSL_AD_RECORD_OVERFLOW;
SSLerror(s, SSL_R_DATA_LENGTH_TOO_LONG);
goto f_err;
}
rr->off = 0;
/* So at this point the following is true
* ssl->s3->internal->rrec.type is the type of record
* ssl->s3->internal->rrec.length == number of bytes in record
* ssl->s3->internal->rrec.off == offset to first valid byte
* ssl->s3->internal->rrec.data == where to take bytes from, increment
* after use :-).
*/
/* we have pulled in a full packet so zero things */
s->internal->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->internal->rrec.type - is the type of record
* ssl->s3->internal->rrec.data, - data
* ssl->s3->internal->rrec.length, - number of bytes
*/
/* used only by dtls1_read_bytes */
int
dtls1_get_record(SSL *s)
{
SSL3_RECORD_INTERNAL *rr;
unsigned char *p = NULL;
DTLS1_BITMAP *bitmap;
unsigned int is_next_epoch;
int n;
rr = &(S3I(s)->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 */
if (0) {
again:
/* dump this record on all retries */
rr->length = 0;
s->internal->packet_length = 0;
}
/* check if we have the header */
if ((s->internal->rstate != SSL_ST_READ_BODY) ||
(s->internal->packet_length < DTLS1_RT_HEADER_LENGTH)) {
CBS header, seq_no;
uint16_t epoch, len, ssl_version;
uint8_t type;
n = ssl3_packet_read(s, DTLS1_RT_HEADER_LENGTH);
if (n <= 0)
return (n);
/* If this packet contained a partial record, dump it. */
if (n != DTLS1_RT_HEADER_LENGTH)
goto again;
s->internal->rstate = SSL_ST_READ_BODY;
CBS_init(&header, s->internal->packet, s->internal->packet_length);
/* Pull apart the header into the DTLS1_RECORD */
if (!CBS_get_u8(&header, &type))
goto again;
if (!CBS_get_u16(&header, &ssl_version))
goto again;
/* sequence number is 64 bits, with top 2 bytes = epoch */
if (!CBS_get_u16(&header, &epoch) ||
!CBS_get_bytes(&header, &seq_no, 6))
goto again;
if (!CBS_write_bytes(&seq_no, &(S3I(s)->read_sequence[2]),
sizeof(S3I(s)->read_sequence) - 2, NULL))
goto again;
if (!CBS_get_u16(&header, &len))
goto again;
rr->type = type;
rr->epoch = epoch;
rr->length = len;
/* unexpected version, silently discard */
if (!s->internal->first_packet && ssl_version != s->version)
goto again;
/* wrong version, silently discard record */
if ((ssl_version & 0xff00) != (s->version & 0xff00))
goto again;
/* record too long, silently discard it */
if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
goto again;
/* now s->internal->rstate == SSL_ST_READ_BODY */
p = (unsigned char *)CBS_data(&header);
}
/* s->internal->rstate == SSL_ST_READ_BODY, get and decode the data */
n = ssl3_packet_extend(s, DTLS1_RT_HEADER_LENGTH + rr->length);
if (n <= 0)
return (n);
/* If this packet contained a partial record, dump it. */
if (n != DTLS1_RT_HEADER_LENGTH + rr->length)
goto again;
s->internal->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)
goto again;
/*
* 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 (!(D1I(s)->listen && rr->type == SSL3_RT_HANDSHAKE &&
p != NULL && *p == SSL3_MT_CLIENT_HELLO) &&
!dtls1_record_replay_check(s, bitmap))
goto again;
/* 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->internal->in_handshake) && !D1I(s)->listen) {
if (dtls1_buffer_record(s, &(D1I(s)->unprocessed_rcds),
rr->seq_num) < 0)
return (-1);
/* Mark receipt of record. */
dtls1_record_bitmap_update(s, bitmap);
}
goto again;
}
if (!dtls1_process_record(s))
goto again;
/* Mark receipt of record. */
dtls1_record_bitmap_update(s, bitmap);
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_INTERNAL *rr;
void (*cb)(const SSL *ssl, int type2, int val) = NULL;
if (S3I(s)->rbuf.buf == NULL) /* Not initialized yet */
if (!ssl3_setup_buffers(s))
return (-1);
if ((type &&
type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) ||
(peek && (type != SSL3_RT_APPLICATION_DATA))) {
SSLerror(s, 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 D1I(s)->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
if (!s->internal->in_handshake && SSL_in_init(s))
{
/* type == SSL3_RT_APPLICATION_DATA */
i = s->internal->handshake_func(s);
if (i < 0)
return (i);
if (i == 0) {
SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
return (-1);
}
}
start:
s->internal->rwstate = SSL_NOTHING;
/* S3I(s)->rrec.type - is the type of record
* S3I(s)->rrec.data, - data
* S3I(s)->rrec.off, - offset into 'data' for next read
* S3I(s)->rrec.length, - number of bytes. */
rr = &(S3I(s)->rrec);
/* We are not handshaking and have no data yet,
* so process data buffered during the last handshake
* in advance, if any.
*/
if (S3I(s)->hs.state == SSL_ST_OK && rr->length == 0) {
pitem *item;
item = pqueue_pop(D1I(s)->buffered_app_data.q);
if (item) {
dtls1_copy_record(s, item);
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->internal->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 (D1I(s)->listen && rr->type != SSL3_RT_HANDSHAKE) {
rr->length = 0;
goto start;
}
/* we now have a packet which can be read and processed */
if (S3I(s)->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, &(D1I(s)->buffered_app_data),
rr->seq_num) < 0) {
SSLerror(s, 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->internal->shutdown & SSL_RECEIVED_SHUTDOWN) {
rr->length = 0;
s->internal->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;
SSLerror(s, 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->internal->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;
unsigned char *dest = NULL;
unsigned int *dest_len = NULL;
if (rr->type == SSL3_RT_HANDSHAKE) {
dest_maxlen = sizeof D1I(s)->handshake_fragment;
dest = D1I(s)->handshake_fragment;
dest_len = &D1I(s)->handshake_fragment_len;
} else if (rr->type == SSL3_RT_ALERT) {
dest_maxlen = sizeof(D1I(s)->alert_fragment);
dest = D1I(s)->alert_fragment;
dest_len = &D1I(s)->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;
S3I(s)->in_read_app_data = 2;
bio = SSL_get_rbio(s);
s->internal->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;
SSLerror(s, 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->internal->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;
}
}
/* D1I(s)->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
* D1I(s)->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) &&
(D1I(s)->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
(D1I(s)->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
(s->session != NULL) && (s->session->cipher != NULL)) {
D1I(s)->handshake_fragment_len = 0;
if ((D1I(s)->handshake_fragment[1] != 0) ||
(D1I(s)->handshake_fragment[2] != 0) ||
(D1I(s)->handshake_fragment[3] != 0)) {
al = SSL_AD_DECODE_ERROR;
SSLerror(s, SSL_R_BAD_HELLO_REQUEST);
goto f_err;
}
/* no need to check sequence number on HELLO REQUEST messages */
if (s->internal->msg_callback)
s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
D1I(s)->handshake_fragment, 4, s, s->internal->msg_callback_arg);
if (SSL_is_init_finished(s) &&
!(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
!S3I(s)->renegotiate) {
D1I(s)->handshake_read_seq++;
s->internal->new_session = 1;
ssl3_renegotiate(s);
if (ssl3_renegotiate_check(s)) {
i = s->internal->handshake_func(s);
if (i < 0)
return (i);
if (i == 0) {
SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
return (-1);
}
if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) {
if (S3I(s)->rbuf.left == 0) /* no read-ahead left? */
{
BIO *bio;
/* In the case where we try to read application data,
* but we trigger an SSL handshake, we return -1 with
* the retry option set. Otherwise renegotiation may
* cause nasty problems in the blocking world */
s->internal->rwstate = SSL_READING;
bio = SSL_get_rbio(s);
BIO_clear_retry_flags(bio);
BIO_set_retry_read(bio);
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 (D1I(s)->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
int alert_level = D1I(s)->alert_fragment[0];
int alert_descr = D1I(s)->alert_fragment[1];
D1I(s)->alert_fragment_len = 0;
if (s->internal->msg_callback)
s->internal->msg_callback(0, s->version, SSL3_RT_ALERT,
D1I(s)->alert_fragment, 2, s, s->internal->msg_callback_arg);
if (s->internal->info_callback != NULL)
cb = s->internal->info_callback;
else if (s->ctx->internal->info_callback != NULL)
cb = s->ctx->internal->info_callback;
if (cb != NULL) {
j = (alert_level << 8) | alert_descr;
cb(s, SSL_CB_READ_ALERT, j);
}
if (alert_level == 1) /* warning */
{
S3I(s)->warn_alert = alert_descr;
if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN;
return (0);
}
} else if (alert_level == 2) /* fatal */
{
s->internal->rwstate = SSL_NOTHING;
S3I(s)->fatal_alert = alert_descr;
SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr);
ERR_asprintf_error_data("SSL alert number %d",
alert_descr);
s->internal->shutdown|=SSL_RECEIVED_SHUTDOWN;
SSL_CTX_remove_session(s->ctx, s->session);
return (0);
} else {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE);
goto f_err;
}
goto start;
}
if (s->internal->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
{
s->internal->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_DECODE_ERROR;
SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC);
goto f_err;
}
rr->length = 0;
if (s->internal->msg_callback)
s->internal->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
rr->data, 1, s, s->internal->msg_callback_arg);
/* We can't process a CCS now, because previous handshake
* messages are still missing, so just drop it.
*/
if (!D1I(s)->change_cipher_spec_ok) {
goto start;
}
D1I(s)->change_cipher_spec_ok = 0;
S3I(s)->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 ((D1I(s)->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
!s->internal->in_handshake) {
struct hm_header_st msg_hdr;
/* this may just be a stale retransmit */
if (!dtls1_get_message_header(rr->data, &msg_hdr))
return -1;
if (rr->epoch != D1I(s)->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 (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) &&
!(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
s->internal->renegotiate = 1;
s->internal->new_session = 1;
}
i = s->internal->handshake_func(s);
if (i < 0)
return (i);
if (i == 0) {
SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
return (-1);
}
if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) {
if (S3I(s)->rbuf.left == 0) /* no read-ahead left? */
{
BIO *bio;
/* In the case where we try to read application data,
* but we trigger an SSL handshake, we return -1 with
* the retry option set. Otherwise renegotiation may
* cause nasty problems in the blocking world */
s->internal->rwstate = SSL_READING;
bio = SSL_get_rbio(s);
BIO_clear_retry_flags(bio);
BIO_set_retry_read(bio);
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;
SSLerror(s, 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->internal->in_handshake is set, but that
* should not happen when type != rr->type */
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerror(s, 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 (S3I(s)->in_read_app_data &&
(S3I(s)->total_renegotiations != 0) &&
(((S3I(s)->hs.state & SSL_ST_CONNECT) &&
(S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) &&
(S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || (
(S3I(s)->hs.state & SSL_ST_ACCEPT) &&
(S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) &&
(S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) {
S3I(s)->in_read_app_data = 2;
return (-1);
} else {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerror(s, 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->internal->in_handshake)
{
i = s->internal->handshake_func(s);
if (i < 0)
return (i);
if (i == 0) {
SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
return -1;
}
}
if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
SSLerror(s, 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, unsigned char *buf,
int len, int peek)
{
if ((type == SSL3_RT_HANDSHAKE) && (D1I(s)->handshake_fragment_len > 0))
/* (partially) satisfy request from storage */
{
unsigned char *src = D1I(s)->handshake_fragment;
unsigned char *dst = buf;
unsigned int k, n;
/* peek == 0 */
n = 0;
while ((len > 0) && (D1I(s)->handshake_fragment_len > 0)) {
*dst++ = *src++;
len--;
D1I(s)->handshake_fragment_len--;
n++;
}
/* move any remaining fragment bytes: */
for (k = 0; k < D1I(s)->handshake_fragment_len; k++)
D1I(s)->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;
OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
s->internal->rwstate = SSL_NOTHING;
i = do_dtls1_write(s, type, buf, len);
return i;
}
int
do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len)
{
SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf);
size_t out_len;
CBB cbb;
int ret;
memset(&cbb, 0, sizeof(cbb));
/*
* First check if there is a SSL3_BUFFER_INTERNAL still being written
* out. This will happen with non blocking IO.
*/
if (wb->left != 0) {
OPENSSL_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, let's send it */
if (S3I(s)->alert_dispatch) {
if ((ret = s->method->ssl_dispatch_alert(s)) <= 0)
return (ret);
/* If it went, fall through and send more stuff. */
}
if (len == 0)
return 0;
wb->offset = 0;
if (!CBB_init_fixed(&cbb, wb->buf, wb->len))
goto err;
tls12_record_layer_set_version(s->internal->rl, s->version);
tls12_record_layer_set_write_epoch(s->internal->rl, D1I(s)->w_epoch);
if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb))
goto err;
if (!CBB_finish(&cbb, NULL, &out_len))
goto err;
wb->left = out_len;
/*
* Memorize arguments so that ssl3_write_pending can detect
* bad write retries later.
*/
S3I(s)->wpend_tot = len;
S3I(s)->wpend_buf = buf;
S3I(s)->wpend_type = type;
S3I(s)->wpend_ret = len;
/* We now just need to write the buffer. */
return ssl3_write_pending(s, type, buf, len);
err:
CBB_cleanup(&cbb);
return -1;
}
static int
dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
{
int cmp;
unsigned int shift;
const unsigned char *seq = S3I(s)->read_sequence;
cmp = satsub64be(seq, bitmap->max_seq_num);
if (cmp > 0) {
memcpy (S3I(s)->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 & (1UL << shift))
return 0; /* record previously received */
memcpy(S3I(s)->rrec.seq_num, seq, 8);
return 1;
}
static void
dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
{
int cmp;
unsigned int shift;
const unsigned char *seq = S3I(s)->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 |= 1UL << shift;
}
}
int
dtls1_dispatch_alert(SSL *s)
{
int i, j;
void (*cb)(const SSL *ssl, int type, int val) = NULL;
unsigned char buf[DTLS1_AL_HEADER_LENGTH];
unsigned char *ptr = &buf[0];
S3I(s)->alert_dispatch = 0;
memset(buf, 0, sizeof(buf));
*ptr++ = S3I(s)->send_alert[0];
*ptr++ = S3I(s)->send_alert[1];
i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf));
if (i <= 0) {
S3I(s)->alert_dispatch = 1;
/* fprintf( stderr, "not done with alert\n" ); */
} else {
if (S3I(s)->send_alert[0] == SSL3_AL_FATAL)
(void)BIO_flush(s->wbio);
if (s->internal->msg_callback)
s->internal->msg_callback(1, s->version, SSL3_RT_ALERT,
S3I(s)->send_alert, 2, s, s->internal->msg_callback_arg);
if (s->internal->info_callback != NULL)
cb = s->internal->info_callback;
else if (s->ctx->internal->info_callback != NULL)
cb = s->ctx->internal->info_callback;
if (cb != NULL) {
j = (S3I(s)->send_alert[0]<<8)|S3I(s)->send_alert[1];
cb(s, SSL_CB_WRITE_ALERT, j);
}
}
return (i);
}
static DTLS1_BITMAP *
dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, unsigned int *is_next_epoch)
{
*is_next_epoch = 0;
/* In current epoch, accept HM, CCS, DATA, & ALERT */
if (rr->epoch == D1I(s)->r_epoch)
return &D1I(s)->bitmap;
/* Only HM and ALERT messages can be from the next epoch */
else if (rr->epoch == (unsigned long)(D1I(s)->r_epoch + 1) &&
(rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
*is_next_epoch = 1;
return &D1I(s)->next_bitmap;
}
return NULL;
}
void
dtls1_reset_seq_numbers(SSL *s, int rw)
{
unsigned char *seq;
unsigned int seq_bytes = sizeof(S3I(s)->read_sequence);
if (rw & SSL3_CC_READ) {
D1I(s)->r_epoch++;
seq = S3I(s)->read_sequence;
memcpy(&(D1I(s)->bitmap), &(D1I(s)->next_bitmap), sizeof(DTLS1_BITMAP));
memset(&(D1I(s)->next_bitmap), 0, sizeof(DTLS1_BITMAP));
} else {
D1I(s)->w_epoch++;
seq = S3I(s)->write_sequence;
memcpy(D1I(s)->last_write_sequence, seq, sizeof(S3I(s)->write_sequence));
}
memset(seq, 0, seq_bytes);
}
Reference in a new issue Copy permalink