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openssl/ssl/d1_lib.c
Matt Caswell a091bc6022 Move freeing of an old record layer to dtls1_clear_sent_buffer 
When we are clearing the sent messages queue we should ensure we free any
old write record layers that are no longer in use. Previously this logic
was in dtls1_hm_fragment_free() - but this can end up freeing the current
record layer under certain error conditions.

Fixes #22664

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22679)
2023-11-21 13:09:28 +01:00

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/*
* Copyright 2005-2023 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include "internal/e_os.h"
#include <stdio.h>
#include <openssl/objects.h>
#include <openssl/rand.h>
#include "ssl_local.h"
#include "internal/time.h"
static int dtls1_handshake_write(SSL_CONNECTION *s);
static size_t dtls1_link_min_mtu(void);
/* XDTLS: figure out the right values */
static const size_t g_probable_mtu[] = { 1500, 512, 256 };
const SSL3_ENC_METHOD DTLSv1_enc_data = {
tls1_setup_key_block,
tls1_generate_master_secret,
tls1_change_cipher_state,
tls1_final_finish_mac,
TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
tls1_alert_code,
tls1_export_keying_material,
SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV,
dtls1_set_handshake_header,
dtls1_close_construct_packet,
dtls1_handshake_write
};
const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
tls1_setup_key_block,
tls1_generate_master_secret,
tls1_change_cipher_state,
tls1_final_finish_mac,
TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
tls1_alert_code,
tls1_export_keying_material,
SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS
| SSL_ENC_FLAG_SHA256_PRF | SSL_ENC_FLAG_TLS1_2_CIPHERS,
dtls1_set_handshake_header,
dtls1_close_construct_packet,
dtls1_handshake_write
};
OSSL_TIME dtls1_default_timeout(void)
{
/*
* 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
* http, the cache would over fill
*/
return ossl_seconds2time(60 * 60 * 2);
}
int dtls1_new(SSL *ssl)
{
DTLS1_STATE *d1;
SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
if (s == NULL)
return 0;
if (!DTLS_RECORD_LAYER_new(&s->rlayer)) {
return 0;
}
if (!ssl3_new(ssl))
return 0;
if ((d1 = OPENSSL_zalloc(sizeof(*d1))) == NULL) {
ssl3_free(ssl);
return 0;
}
d1->buffered_messages = pqueue_new();
d1->sent_messages = pqueue_new();
if (s->server) {
d1->cookie_len = sizeof(s->d1->cookie);
}
d1->link_mtu = 0;
d1->mtu = 0;
if (d1->buffered_messages == NULL || d1->sent_messages == NULL) {
pqueue_free(d1->buffered_messages);
pqueue_free(d1->sent_messages);
OPENSSL_free(d1);
ssl3_free(ssl);
return 0;
}
s->d1 = d1;
if (!ssl->method->ssl_clear(ssl))
return 0;
return 1;
}
static void dtls1_clear_queues(SSL_CONNECTION *s)
{
dtls1_clear_received_buffer(s);
dtls1_clear_sent_buffer(s);
}
void dtls1_clear_received_buffer(SSL_CONNECTION *s)
{
pitem *item = NULL;
hm_fragment *frag = NULL;
while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
frag = (hm_fragment *)item->data;
dtls1_hm_fragment_free(frag);
pitem_free(item);
}
}
void dtls1_clear_sent_buffer(SSL_CONNECTION *s)
{
pitem *item = NULL;
hm_fragment *frag = NULL;
while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
frag = (hm_fragment *)item->data;
if (frag->msg_header.is_ccs
&& frag->msg_header.saved_retransmit_state.wrlmethod != NULL
&& s->rlayer.wrl != frag->msg_header.saved_retransmit_state.wrl) {
/*
* If we're freeing the CCS then we're done with the old wrl and it
* can bee freed
*/
frag->msg_header.saved_retransmit_state.wrlmethod->free(frag->msg_header.saved_retransmit_state.wrl);
}
dtls1_hm_fragment_free(frag);
pitem_free(item);
}
}
void dtls1_free(SSL *ssl)
{
SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
if (s == NULL)
return;
if (s->d1 != NULL) {
dtls1_clear_queues(s);
pqueue_free(s->d1->buffered_messages);
pqueue_free(s->d1->sent_messages);
}
DTLS_RECORD_LAYER_free(&s->rlayer);
ssl3_free(ssl);
OPENSSL_free(s->d1);
s->d1 = NULL;
}
int dtls1_clear(SSL *ssl)
{
pqueue *buffered_messages;
pqueue *sent_messages;
size_t mtu;
size_t link_mtu;
SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
if (s == NULL)
return 0;
DTLS_RECORD_LAYER_clear(&s->rlayer);
if (s->d1) {
DTLS_timer_cb timer_cb = s->d1->timer_cb;
buffered_messages = s->d1->buffered_messages;
sent_messages = s->d1->sent_messages;
mtu = s->d1->mtu;
link_mtu = s->d1->link_mtu;
dtls1_clear_queues(s);
memset(s->d1, 0, sizeof(*s->d1));
/* Restore the timer callback from previous state */
s->d1->timer_cb = timer_cb;
if (s->server) {
s->d1->cookie_len = sizeof(s->d1->cookie);
}
if (SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU) {
s->d1->mtu = mtu;
s->d1->link_mtu = link_mtu;
}
s->d1->buffered_messages = buffered_messages;
s->d1->sent_messages = sent_messages;
}
if (!ssl3_clear(ssl))
return 0;
if (ssl->method->version == DTLS_ANY_VERSION)
s->version = DTLS_MAX_VERSION_INTERNAL;
#ifndef OPENSSL_NO_DTLS1_METHOD
else if (s->options & SSL_OP_CISCO_ANYCONNECT)
s->client_version = s->version = DTLS1_BAD_VER;
#endif
else
s->version = ssl->method->version;
return 1;
}
long dtls1_ctrl(SSL *ssl, int cmd, long larg, void *parg)
{
int ret = 0;
OSSL_TIME t;
SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
if (s == NULL)
return 0;
switch (cmd) {
case DTLS_CTRL_GET_TIMEOUT:
if (dtls1_get_timeout(s, &t)) {
*(struct timeval *)parg = ossl_time_to_timeval(t);
ret = 1;
}
break;
case DTLS_CTRL_HANDLE_TIMEOUT:
ret = dtls1_handle_timeout(s);
break;
case DTLS_CTRL_SET_LINK_MTU:
if (larg < (long)dtls1_link_min_mtu())
return 0;
s->d1->link_mtu = larg;
return 1;
case DTLS_CTRL_GET_LINK_MIN_MTU:
return (long)dtls1_link_min_mtu();
case SSL_CTRL_SET_MTU:
/*
* We may not have a BIO set yet so can't call dtls1_min_mtu()
* We'll have to make do with dtls1_link_min_mtu() and max overhead
*/
if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
return 0;
s->d1->mtu = larg;
return larg;
default:
ret = ssl3_ctrl(ssl, cmd, larg, parg);
break;
}
return ret;
}
static void dtls1_bio_set_next_timeout(BIO *bio, const DTLS1_STATE *d1)
{
struct timeval tv = ossl_time_to_timeval(d1->next_timeout);
BIO_ctrl(bio, BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &tv);
}
void dtls1_start_timer(SSL_CONNECTION *s)
{
OSSL_TIME duration;
SSL *ssl = SSL_CONNECTION_GET_SSL(s);
#ifndef OPENSSL_NO_SCTP
/* Disable timer for SCTP */
if (BIO_dgram_is_sctp(SSL_get_wbio(ssl))) {
s->d1->next_timeout = ossl_time_zero();
return;
}
#endif
/*
* If timer is not set, initialize duration with 1 second or
* a user-specified value if the timer callback is installed.
*/
if (ossl_time_is_zero(s->d1->next_timeout)) {
if (s->d1->timer_cb != NULL)
s->d1->timeout_duration_us = s->d1->timer_cb(ssl, 0);
else
s->d1->timeout_duration_us = 1000000;
}
/* Set timeout to current time plus duration */
duration = ossl_us2time(s->d1->timeout_duration_us);
s->d1->next_timeout = ossl_time_add(ossl_time_now(), duration);
/* set s->d1->next_timeout into ssl->rbio interface */
dtls1_bio_set_next_timeout(SSL_get_rbio(ssl), s->d1);
}
int dtls1_get_timeout(const SSL_CONNECTION *s, OSSL_TIME *timeleft)
{
OSSL_TIME timenow;
/* If no timeout is set, just return NULL */
if (ossl_time_is_zero(s->d1->next_timeout))
return 0;
/* Get current time */
timenow = ossl_time_now();
/*
* If timer already expired or if remaining time is less than 15 ms,
* set it to 0 to prevent issues because of small divergences with
* socket timeouts.
*/
*timeleft = ossl_time_subtract(s->d1->next_timeout, timenow);
if (ossl_time_compare(*timeleft, ossl_ms2time(15)) <= 0)
*timeleft = ossl_time_zero();
return 1;
}
int dtls1_is_timer_expired(SSL_CONNECTION *s)
{
OSSL_TIME timeleft;
/* Get time left until timeout, return false if no timer running */
if (!dtls1_get_timeout(s, &timeleft))
return 0;
/* Return false if timer is not expired yet */
if (!ossl_time_is_zero(timeleft))
return 0;
/* Timer expired, so return true */
return 1;
}
static void dtls1_double_timeout(SSL_CONNECTION *s)
{
s->d1->timeout_duration_us *= 2;
if (s->d1->timeout_duration_us > 60000000)
s->d1->timeout_duration_us = 60000000;
}
void dtls1_stop_timer(SSL_CONNECTION *s)
{
/* Reset everything */
s->d1->timeout_num_alerts = 0;
s->d1->next_timeout = ossl_time_zero();
s->d1->timeout_duration_us = 1000000;
dtls1_bio_set_next_timeout(s->rbio, s->d1);
/* Clear retransmission buffer */
dtls1_clear_sent_buffer(s);
}
int dtls1_check_timeout_num(SSL_CONNECTION *s)
{
size_t mtu;
SSL *ssl = SSL_CONNECTION_GET_SSL(s);
s->d1->timeout_num_alerts++;
/* Reduce MTU after 2 unsuccessful retransmissions */
if (s->d1->timeout_num_alerts > 2
&& !(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) {
mtu =
BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
if (mtu < s->d1->mtu)
s->d1->mtu = mtu;
}
if (s->d1->timeout_num_alerts > DTLS1_TMO_ALERT_COUNT) {
/* fail the connection, enough alerts have been sent */
SSLfatal(s, SSL_AD_NO_ALERT, SSL_R_READ_TIMEOUT_EXPIRED);
return -1;
}
return 0;
}
int dtls1_handle_timeout(SSL_CONNECTION *s)
{
/* if no timer is expired, don't do anything */
if (!dtls1_is_timer_expired(s)) {
return 0;
}
if (s->d1->timer_cb != NULL)
s->d1->timeout_duration_us = s->d1->timer_cb(SSL_CONNECTION_GET_SSL(s),
s->d1->timeout_duration_us);
else
dtls1_double_timeout(s);
if (dtls1_check_timeout_num(s) < 0) {
/* SSLfatal() already called */
return -1;
}
dtls1_start_timer(s);
/* Calls SSLfatal() if required */
return dtls1_retransmit_buffered_messages(s);
}
#define LISTEN_SUCCESS 2
#define LISTEN_SEND_VERIFY_REQUEST 1
#ifndef OPENSSL_NO_SOCK
int DTLSv1_listen(SSL *ssl, BIO_ADDR *client)
{
int next, n, ret = 0;
unsigned char cookie[DTLS1_COOKIE_LENGTH];
unsigned char seq[SEQ_NUM_SIZE];
const unsigned char *data;
unsigned char *buf = NULL, *wbuf;
size_t fragoff, fraglen, msglen;
unsigned int rectype, versmajor, versminor, msgseq, msgtype, clientvers, cookielen;
BIO *rbio, *wbio;
BIO_ADDR *tmpclient = NULL;
PACKET pkt, msgpkt, msgpayload, session, cookiepkt;
SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
if (s == NULL)
return -1;
if (s->handshake_func == NULL) {
/* Not properly initialized yet */
SSL_set_accept_state(ssl);
}
/* Ensure there is no state left over from a previous invocation */
if (!SSL_clear(ssl))
return -1;
ERR_clear_error();
rbio = SSL_get_rbio(ssl);
wbio = SSL_get_wbio(ssl);
if (!rbio || !wbio) {
ERR_raise(ERR_LIB_SSL, SSL_R_BIO_NOT_SET);
return -1;
}
/*
* Note: This check deliberately excludes DTLS1_BAD_VER because that version
* requires the MAC to be calculated *including* the first ClientHello
* (without the cookie). Since DTLSv1_listen is stateless that cannot be
* supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
* SSL_accept)
*/
if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
ERR_raise(ERR_LIB_SSL, SSL_R_UNSUPPORTED_SSL_VERSION);
return -1;
}
buf = OPENSSL_malloc(DTLS1_RT_HEADER_LENGTH + SSL3_RT_MAX_PLAIN_LENGTH);
if (buf == NULL)
return -1;
wbuf = OPENSSL_malloc(DTLS1_RT_HEADER_LENGTH + SSL3_RT_MAX_PLAIN_LENGTH);
if (wbuf == NULL) {
OPENSSL_free(buf);
return -1;
}
do {
/* Get a packet */
clear_sys_error();
n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH
+ DTLS1_RT_HEADER_LENGTH);
if (n <= 0) {
if (BIO_should_retry(rbio)) {
/* Non-blocking IO */
goto end;
}
ret = -1;
goto end;
}
if (!PACKET_buf_init(&pkt, buf, n)) {
ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
ret = -1;
goto end;
}
/*
* Parse the received record. If there are any problems with it we just
* dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
* resilient in the face of invalid records (e.g., invalid formatting,
* length, MAC, etc.). In general, invalid records SHOULD be silently
* discarded, thus preserving the association; however, an error MAY be
* logged for diagnostic purposes."
*/
/* this packet contained a partial record, dump it */
if (n < DTLS1_RT_HEADER_LENGTH) {
ERR_raise(ERR_LIB_SSL, SSL_R_RECORD_TOO_SMALL);
goto end;
}
/* Get the record header */
if (!PACKET_get_1(&pkt, &rectype)
|| !PACKET_get_1(&pkt, &versmajor)
|| !PACKET_get_1(&pkt, &versminor)) {
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
goto end;
}
if (s->msg_callback)
s->msg_callback(0, (versmajor << 8) | versminor, SSL3_RT_HEADER, buf,
DTLS1_RT_HEADER_LENGTH, ssl, s->msg_callback_arg);
if (rectype != SSL3_RT_HANDSHAKE) {
ERR_raise(ERR_LIB_SSL, SSL_R_UNEXPECTED_MESSAGE);
goto end;
}
/*
* Check record version number. We only check that the major version is
* the same.
*/
if (versmajor != DTLS1_VERSION_MAJOR) {
ERR_raise(ERR_LIB_SSL, SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
goto end;
}
/* Save the sequence number: 64 bits, with top 2 bytes = epoch */
if (!PACKET_copy_bytes(&pkt, seq, SEQ_NUM_SIZE)
|| !PACKET_get_length_prefixed_2(&pkt, &msgpkt)) {
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
goto end;
}
/*
* We allow data remaining at the end of the packet because there could
* be a second record (but we ignore it)
*/
/* This is an initial ClientHello so the epoch has to be 0 */
if (seq[0] != 0 || seq[1] != 0) {
ERR_raise(ERR_LIB_SSL, SSL_R_UNEXPECTED_MESSAGE);
goto end;
}
/* Get a pointer to the raw message for the later callback */
data = PACKET_data(&msgpkt);
/* Finished processing the record header, now process the message */
if (!PACKET_get_1(&msgpkt, &msgtype)
|| !PACKET_get_net_3_len(&msgpkt, &msglen)
|| !PACKET_get_net_2(&msgpkt, &msgseq)
|| !PACKET_get_net_3_len(&msgpkt, &fragoff)
|| !PACKET_get_net_3_len(&msgpkt, &fraglen)
|| !PACKET_get_sub_packet(&msgpkt, &msgpayload, fraglen)
|| PACKET_remaining(&msgpkt) != 0) {
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
goto end;
}
if (msgtype != SSL3_MT_CLIENT_HELLO) {
ERR_raise(ERR_LIB_SSL, SSL_R_UNEXPECTED_MESSAGE);
goto end;
}
/* Message sequence number can only be 0 or 1 */
if (msgseq > 2) {
ERR_raise(ERR_LIB_SSL, SSL_R_INVALID_SEQUENCE_NUMBER);
goto end;
}
/*
* We don't support fragment reassembly for ClientHellos whilst
* listening because that would require server side state (which is
* against the whole point of the ClientHello/HelloVerifyRequest
* mechanism). Instead we only look at the first ClientHello fragment
* and require that the cookie must be contained within it.
*/
if (fragoff != 0 || fraglen > msglen) {
/* Non initial ClientHello fragment (or bad fragment) */
ERR_raise(ERR_LIB_SSL, SSL_R_FRAGMENTED_CLIENT_HELLO);
goto end;
}
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, data,
fraglen + DTLS1_HM_HEADER_LENGTH, ssl,
s->msg_callback_arg);
if (!PACKET_get_net_2(&msgpayload, &clientvers)) {
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
goto end;
}
/*
* Verify client version is supported
*/
if (DTLS_VERSION_LT(clientvers, (unsigned int)ssl->method->version) &&
ssl->method->version != DTLS_ANY_VERSION) {
ERR_raise(ERR_LIB_SSL, SSL_R_WRONG_VERSION_NUMBER);
goto end;
}
if (!PACKET_forward(&msgpayload, SSL3_RANDOM_SIZE)
|| !PACKET_get_length_prefixed_1(&msgpayload, &session)
|| !PACKET_get_length_prefixed_1(&msgpayload, &cookiepkt)) {
/*
* Could be malformed or the cookie does not fit within the initial
* ClientHello fragment. Either way we can't handle it.
*/
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
goto end;
}
/*
* Check if we have a cookie or not. If not we need to send a
* HelloVerifyRequest.
*/
if (PACKET_remaining(&cookiepkt) == 0) {
next = LISTEN_SEND_VERIFY_REQUEST;
} else {
/*
* We have a cookie, so lets check it.
*/
if (ssl->ctx->app_verify_cookie_cb == NULL) {
ERR_raise(ERR_LIB_SSL, SSL_R_NO_VERIFY_COOKIE_CALLBACK);
/* This is fatal */
ret = -1;
goto end;
}
if (ssl->ctx->app_verify_cookie_cb(ssl, PACKET_data(&cookiepkt),
(unsigned int)PACKET_remaining(&cookiepkt)) == 0) {
/*
* We treat invalid cookies in the same was as no cookie as
* per RFC6347
*/
next = LISTEN_SEND_VERIFY_REQUEST;
} else {
/* Cookie verification succeeded */
next = LISTEN_SUCCESS;
}
}
if (next == LISTEN_SEND_VERIFY_REQUEST) {
WPACKET wpkt;
unsigned int version;
size_t wreclen;
/*
* There was no cookie in the ClientHello so we need to send a
* HelloVerifyRequest. If this fails we do not worry about trying
* to resend, we just drop it.
*/
/* Generate the cookie */
if (ssl->ctx->app_gen_cookie_cb == NULL ||
ssl->ctx->app_gen_cookie_cb(ssl, cookie, &cookielen) == 0 ||
cookielen > 255) {
ERR_raise(ERR_LIB_SSL, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
/* This is fatal */
ret = -1;
goto end;
}
/*
* 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.
*/
version = (ssl->method->version == DTLS_ANY_VERSION) ? DTLS1_VERSION
: s->version;
/* Construct the record and message headers */
if (!WPACKET_init_static_len(&wpkt,
wbuf,
ssl_get_max_send_fragment(s)
+ DTLS1_RT_HEADER_LENGTH,
0)
|| !WPACKET_put_bytes_u8(&wpkt, SSL3_RT_HANDSHAKE)
|| !WPACKET_put_bytes_u16(&wpkt, version)
/*
* Record sequence number is always the same as in the
* received ClientHello
*/
|| !WPACKET_memcpy(&wpkt, seq, SEQ_NUM_SIZE)
/* End of record, start sub packet for message */
|| !WPACKET_start_sub_packet_u16(&wpkt)
/* Message type */
|| !WPACKET_put_bytes_u8(&wpkt,
DTLS1_MT_HELLO_VERIFY_REQUEST)
/*
* Message length - doesn't follow normal TLS convention:
* the length isn't the last thing in the message header.
* We'll need to fill this in later when we know the
* length. Set it to zero for now
*/
|| !WPACKET_put_bytes_u24(&wpkt, 0)
/*
* Message sequence number is always 0 for a
* HelloVerifyRequest
*/
|| !WPACKET_put_bytes_u16(&wpkt, 0)
/*
* We never fragment a HelloVerifyRequest, so fragment
* offset is 0
*/
|| !WPACKET_put_bytes_u24(&wpkt, 0)
/*
* Fragment length is the same as message length, but
* this *is* the last thing in the message header so we
* can just start a sub-packet. No need to come back
* later for this one.
*/
|| !WPACKET_start_sub_packet_u24(&wpkt)
/* Create the actual HelloVerifyRequest body */
|| !dtls_raw_hello_verify_request(&wpkt, cookie, cookielen)
/* Close message body */
|| !WPACKET_close(&wpkt)
/* Close record body */
|| !WPACKET_close(&wpkt)
|| !WPACKET_get_total_written(&wpkt, &wreclen)
|| !WPACKET_finish(&wpkt)) {
ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
WPACKET_cleanup(&wpkt);
/* This is fatal */
ret = -1;
goto end;
}
/*
* Fix up the message len in the message header. Its the same as the
* fragment len which has been filled in by WPACKET, so just copy
* that. Destination for the message len is after the record header
* plus one byte for the message content type. The source is the
* last 3 bytes of the message header
*/
memcpy(&wbuf[DTLS1_RT_HEADER_LENGTH + 1],
&wbuf[DTLS1_RT_HEADER_LENGTH + DTLS1_HM_HEADER_LENGTH - 3],
3);
if (s->msg_callback)
s->msg_callback(1, 0, SSL3_RT_HEADER, buf,
DTLS1_RT_HEADER_LENGTH, ssl,
s->msg_callback_arg);
if ((tmpclient = BIO_ADDR_new()) == NULL) {
ERR_raise(ERR_LIB_SSL, ERR_R_BIO_LIB);
goto end;
}
/*
* This is unnecessary if rbio and wbio are one and the same - but
* maybe they're not. We ignore errors here - some BIOs do not
* support this.
*/
if (BIO_dgram_get_peer(rbio, tmpclient) > 0) {
(void)BIO_dgram_set_peer(wbio, tmpclient);
}
BIO_ADDR_free(tmpclient);
tmpclient = NULL;
if (BIO_write(wbio, wbuf, wreclen) < (int)wreclen) {
if (BIO_should_retry(wbio)) {
/*
* Non-blocking IO...but we're stateless, so we're just
* going to drop this packet.
*/
goto end;
}
ret = -1;
goto end;
}
if (BIO_flush(wbio) <= 0) {
if (BIO_should_retry(wbio)) {
/*
* Non-blocking IO...but we're stateless, so we're just
* going to drop this packet.
*/
goto end;
}
ret = -1;
goto end;
}
}
} while (next != LISTEN_SUCCESS);
/*
* Set expected sequence numbers to continue the handshake.
*/
s->d1->handshake_read_seq = 1;
s->d1->handshake_write_seq = 1;
s->d1->next_handshake_write_seq = 1;
s->rlayer.wrlmethod->increment_sequence_ctr(s->rlayer.wrl);
/*
* We are doing cookie exchange, so make sure we set that option in the
* SSL object
*/
SSL_set_options(ssl, SSL_OP_COOKIE_EXCHANGE);
/*
* Tell the state machine that we've done the initial hello verify
* exchange
*/
ossl_statem_set_hello_verify_done(s);
/*
* Some BIOs may not support this. If we fail we clear the client address
*/
if (BIO_dgram_get_peer(rbio, client) <= 0)
BIO_ADDR_clear(client);
/* Buffer the record for use by the record layer */
if (BIO_write(s->rlayer.rrlnext, buf, n) != n) {
ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
ret = -1;
goto end;
}
/*
* Reset the record layer - but this time we can use the record we just
* buffered in s->rlayer.rrlnext
*/
if (!ssl_set_new_record_layer(s,
DTLS_ANY_VERSION,
OSSL_RECORD_DIRECTION_READ,
OSSL_RECORD_PROTECTION_LEVEL_NONE, NULL, 0,
NULL, 0, NULL, 0, NULL, 0, NULL, 0,
NID_undef, NULL, NULL, NULL)) {
/* SSLfatal already called */
ret = -1;
goto end;
}
ret = 1;
end:
BIO_ADDR_free(tmpclient);
OPENSSL_free(buf);
OPENSSL_free(wbuf);
return ret;
}
#endif
static int dtls1_handshake_write(SSL_CONNECTION *s)
{
return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
}
int dtls1_shutdown(SSL *s)
{
int ret;
#ifndef OPENSSL_NO_SCTP
BIO *wbio;
SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL_ONLY(s);
if (s == NULL)
return -1;
wbio = SSL_get_wbio(s);
if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&
!(sc->shutdown & SSL_SENT_SHUTDOWN)) {
ret = BIO_dgram_sctp_wait_for_dry(wbio);
if (ret < 0)
return -1;
if (ret == 0)
BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
NULL);
}
#endif
ret = ssl3_shutdown(s);
#ifndef OPENSSL_NO_SCTP
BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
#endif
return ret;
}
int dtls1_query_mtu(SSL_CONNECTION *s)
{
SSL *ssl = SSL_CONNECTION_GET_SSL(s);
if (s->d1->link_mtu) {
s->d1->mtu =
s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(ssl));
s->d1->link_mtu = 0;
}
/* AHA! Figure out the MTU, and stick to the right size */
if (s->d1->mtu < dtls1_min_mtu(s)) {
if (!(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) {
s->d1->mtu =
BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
/*
* I've seen the kernel return bogus numbers when it doesn't know
* (initial write), so just make sure we have a reasonable number
*/
if (s->d1->mtu < dtls1_min_mtu(s)) {
/* Set to min mtu */
s->d1->mtu = dtls1_min_mtu(s);
BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_SET_MTU,
(long)s->d1->mtu, NULL);
}
} else
return 0;
}
return 1;
}
static size_t dtls1_link_min_mtu(void)
{
return (g_probable_mtu[(sizeof(g_probable_mtu) /
sizeof(g_probable_mtu[0])) - 1]);
}
size_t dtls1_min_mtu(SSL_CONNECTION *s)
{
SSL *ssl = SSL_CONNECTION_GET_SSL(s);
return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(ssl));
}
size_t DTLS_get_data_mtu(const SSL *ssl)
{
size_t mac_overhead, int_overhead, blocksize, ext_overhead;
const SSL_CIPHER *ciph = SSL_get_current_cipher(ssl);
size_t mtu;
const SSL_CONNECTION *s = SSL_CONNECTION_FROM_CONST_SSL_ONLY(ssl);
if (s == NULL)
return 0;
mtu = s->d1->mtu;
if (ciph == NULL)
return 0;
if (!ssl_cipher_get_overhead(ciph, &mac_overhead, &int_overhead,
&blocksize, &ext_overhead))
return 0;
if (SSL_READ_ETM(s))
ext_overhead += mac_overhead;
else
int_overhead += mac_overhead;
/* Subtract external overhead (e.g. IV/nonce, separate MAC) */
if (ext_overhead + DTLS1_RT_HEADER_LENGTH >= mtu)
return 0;
mtu -= ext_overhead + DTLS1_RT_HEADER_LENGTH;
/* Round encrypted payload down to cipher block size (for CBC etc.)
* No check for overflow since 'mtu % blocksize' cannot exceed mtu. */
if (blocksize)
mtu -= (mtu % blocksize);
/* Subtract internal overhead (e.g. CBC padding len byte) */
if (int_overhead >= mtu)
return 0;
mtu -= int_overhead;
return mtu;
}
void DTLS_set_timer_cb(SSL *ssl, DTLS_timer_cb cb)
{
SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
if (s == NULL)
return;
s->d1->timer_cb = cb;
}
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