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openssl/ssl/d1_clnt.c
Matt Caswell 00a4c14214 Fix DTLS buffered message DoS attack 
DTLS can handle out of order record delivery. Additionally since
handshake messages can be bigger than will fit into a single packet, the
messages can be fragmented across multiple records (as with normal TLS).
That means that the messages can arrive mixed up, and we have to
reassemble them. We keep a queue of buffered messages that are "from the
future", i.e. messages we're not ready to deal with yet but have arrived
early. The messages held there may not be full yet - they could be one
or more fragments that are still in the process of being reassembled.

The code assumes that we will eventually complete the reassembly and
when that occurs the complete message is removed from the queue at the
point that we need to use it.

However, DTLS is also tolerant of packet loss. To get around that DTLS
messages can be retransmitted. If we receive a full (non-fragmented)
message from the peer after previously having received a fragment of
that message, then we ignore the message in the queue and just use the
non-fragmented version. At that point the queued message will never get
removed.

Additionally the peer could send "future" messages that we never get to
in order to complete the handshake. Each message has a sequence number
(starting from 0). We will accept a message fragment for the current
message sequence number, or for any sequence up to 10 into the future.
However if the Finished message has a sequence number of 2, anything
greater than that in the queue is just left there.

So, in those two ways we can end up with "orphaned" data in the queue
that will never get removed - except when the connection is closed. At
that point all the queues are flushed.

An attacker could seek to exploit this by filling up the queues with
lots of large messages that are never going to be used in order to
attempt a DoS by memory exhaustion.

I will assume that we are only concerned with servers here. It does not
seem reasonable to be concerned about a memory exhaustion attack on a
client. They are unlikely to process enough connections for this to be
an issue.

A "long" handshake with many messages might be 5 messages long (in the
incoming direction), e.g. ClientHello, Certificate, ClientKeyExchange,
CertificateVerify, Finished. So this would be message sequence numbers 0
to 4. Additionally we can buffer up to 10 messages in the future.
Therefore the maximum number of messages that an attacker could send
that could get orphaned would typically be 15.

The maximum size that a DTLS message is allowed to be is defined by
max_cert_list, which by default is 100k. Therefore the maximum amount of
"orphaned" memory per connection is 1500k.

Message sequence numbers get reset after the Finished message, so
renegotiation will not extend the maximum number of messages that can be
orphaned per connection.

As noted above, the queues do get cleared when the connection is closed.
Therefore in order to mount an effective attack, an attacker would have
to open many simultaneous connections.

Issue reported by Quan Luo.

CVE-2016-2179

Reviewed-by: Richard Levitte <levitte@openssl.org>
2016-08-22 11:03:14 +01:00

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/* ssl/d1_clnt.c */
/*
* DTLS implementation written by Nagendra Modadugu
* (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
*/
/* ====================================================================
* Copyright (c) 1999-2007 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 "ssl_locl.h"
#ifndef OPENSSL_NO_KRB5
# include "kssl_lcl.h"
#endif
#include <openssl/buffer.h>
#include <openssl/rand.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/md5.h>
#include <openssl/bn.h>
#ifndef OPENSSL_NO_DH
# include <openssl/dh.h>
#endif
static const SSL_METHOD *dtls1_get_client_method(int ver);
static int dtls1_get_hello_verify(SSL *s);
static const SSL_METHOD *dtls1_get_client_method(int ver)
{
if (ver == DTLS1_VERSION || ver == DTLS1_BAD_VER)
return (DTLSv1_client_method());
else
return (NULL);
}
IMPLEMENT_dtls1_meth_func(DTLSv1_client_method,
ssl_undefined_function,
dtls1_connect, dtls1_get_client_method)
int dtls1_connect(SSL *s)
{
BUF_MEM *buf = NULL;
unsigned long Time = (unsigned long)time(NULL);
void (*cb) (const SSL *ssl, int type, int val) = NULL;
int ret = -1;
int new_state, state, skip = 0;
#ifndef OPENSSL_NO_SCTP
unsigned char sctpauthkey[64];
char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
#endif
RAND_add(&Time, sizeof(Time), 0);
ERR_clear_error();
clear_sys_error();
if (s->info_callback != NULL)
cb = s->info_callback;
else if (s->ctx->info_callback != NULL)
cb = s->ctx->info_callback;
s->in_handshake++;
if (!SSL_in_init(s) || SSL_in_before(s))
SSL_clear(s);
#ifndef OPENSSL_NO_SCTP
/*
* Notify SCTP BIO socket to enter handshake mode and prevent stream
* identifier other than 0. Will be ignored if no SCTP is used.
*/
BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
s->in_handshake, NULL);
#endif
#ifndef OPENSSL_NO_HEARTBEATS
/*
* If we're awaiting a HeartbeatResponse, pretend we already got and
* don't await it anymore, because Heartbeats don't make sense during
* handshakes anyway.
*/
if (s->tlsext_hb_pending) {
dtls1_stop_timer(s);
s->tlsext_hb_pending = 0;
s->tlsext_hb_seq++;
}
#endif
for (;;) {
state = s->state;
switch (s->state) {
case SSL_ST_RENEGOTIATE:
s->renegotiate = 1;
s->state = SSL_ST_CONNECT;
s->ctx->stats.sess_connect_renegotiate++;
/* break */
case SSL_ST_BEFORE:
case SSL_ST_CONNECT:
case SSL_ST_BEFORE | SSL_ST_CONNECT:
case SSL_ST_OK | SSL_ST_CONNECT:
s->server = 0;
if (cb != NULL)
cb(s, SSL_CB_HANDSHAKE_START, 1);
if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
(s->version & 0xff00) != (DTLS1_BAD_VER & 0xff00)) {
SSLerr(SSL_F_DTLS1_CONNECT, ERR_R_INTERNAL_ERROR);
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
/* s->version=SSL3_VERSION; */
s->type = SSL_ST_CONNECT;
if (s->init_buf == NULL) {
if ((buf = BUF_MEM_new()) == NULL) {
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
s->init_buf = buf;
buf = NULL;
}
if (!ssl3_setup_buffers(s)) {
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
/* setup buffing BIO */
if (!ssl_init_wbio_buffer(s, 0)) {
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
/* don't push the buffering BIO quite yet */
s->state = SSL3_ST_CW_CLNT_HELLO_A;
s->ctx->stats.sess_connect++;
s->init_num = 0;
/* mark client_random uninitialized */
memset(s->s3->client_random, 0, sizeof(s->s3->client_random));
s->d1->send_cookie = 0;
s->hit = 0;
s->d1->change_cipher_spec_ok = 0;
/*
* Should have been reset by ssl3_get_finished, too.
*/
s->s3->change_cipher_spec = 0;
break;
#ifndef OPENSSL_NO_SCTP
case DTLS1_SCTP_ST_CR_READ_SOCK:
if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
s->s3->in_read_app_data = 2;
s->rwstate = SSL_READING;
BIO_clear_retry_flags(SSL_get_rbio(s));
BIO_set_retry_read(SSL_get_rbio(s));
ret = -1;
goto end;
}
s->state = s->s3->tmp.next_state;
break;
case DTLS1_SCTP_ST_CW_WRITE_SOCK:
/* read app data until dry event */
ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
if (ret < 0)
goto end;
if (ret == 0) {
s->s3->in_read_app_data = 2;
s->rwstate = SSL_READING;
BIO_clear_retry_flags(SSL_get_rbio(s));
BIO_set_retry_read(SSL_get_rbio(s));
ret = -1;
goto end;
}
s->state = s->d1->next_state;
break;
#endif
case SSL3_ST_CW_CLNT_HELLO_A:
s->shutdown = 0;
/* every DTLS ClientHello resets Finished MAC */
ssl3_init_finished_mac(s);
case SSL3_ST_CW_CLNT_HELLO_B:
dtls1_start_timer(s);
ret = dtls1_client_hello(s);
if (ret <= 0)
goto end;
if (s->d1->send_cookie) {
s->state = SSL3_ST_CW_FLUSH;
s->s3->tmp.next_state = SSL3_ST_CR_SRVR_HELLO_A;
} else
s->state = SSL3_ST_CR_SRVR_HELLO_A;
s->init_num = 0;
#ifndef OPENSSL_NO_SCTP
/* Disable buffering for SCTP */
if (!BIO_dgram_is_sctp(SSL_get_wbio(s))) {
#endif
/*
* turn on buffering for the next lot of output
*/
if (s->bbio != s->wbio)
s->wbio = BIO_push(s->bbio, s->wbio);
#ifndef OPENSSL_NO_SCTP
}
#endif
break;
case SSL3_ST_CR_SRVR_HELLO_A:
case SSL3_ST_CR_SRVR_HELLO_B:
ret = ssl3_get_server_hello(s);
if (ret <= 0)
goto end;
else {
if (s->hit) {
#ifndef OPENSSL_NO_SCTP
/*
* Add new shared key for SCTP-Auth, will be ignored if
* no SCTP used.
*/
snprintf((char *)labelbuffer,
sizeof(DTLS1_SCTP_AUTH_LABEL),
DTLS1_SCTP_AUTH_LABEL);
if (SSL_export_keying_material(s, sctpauthkey,
sizeof(sctpauthkey),
labelbuffer,
sizeof(labelbuffer), NULL, 0,
0) <= 0) {
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
BIO_ctrl(SSL_get_wbio(s),
BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
sizeof(sctpauthkey), sctpauthkey);
#endif
s->state = SSL3_ST_CR_FINISHED_A;
if (s->tlsext_ticket_expected) {
/* receive renewed session ticket */
s->state = SSL3_ST_CR_SESSION_TICKET_A;
}
} else
s->state = DTLS1_ST_CR_HELLO_VERIFY_REQUEST_A;
}
s->init_num = 0;
break;
case DTLS1_ST_CR_HELLO_VERIFY_REQUEST_A:
case DTLS1_ST_CR_HELLO_VERIFY_REQUEST_B:
ret = dtls1_get_hello_verify(s);
if (ret <= 0)
goto end;
dtls1_stop_timer(s);
if (s->d1->send_cookie) /* start again, with a cookie */
s->state = SSL3_ST_CW_CLNT_HELLO_A;
else
s->state = SSL3_ST_CR_CERT_A;
s->init_num = 0;
break;
case SSL3_ST_CR_CERT_A:
case SSL3_ST_CR_CERT_B:
/* Check if it is anon DH or PSK */
if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
!(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
ret = ssl3_get_server_certificate(s);
if (ret <= 0)
goto end;
#ifndef OPENSSL_NO_TLSEXT
if (s->tlsext_status_expected)
s->state = SSL3_ST_CR_CERT_STATUS_A;
else
s->state = SSL3_ST_CR_KEY_EXCH_A;
} else {
skip = 1;
s->state = SSL3_ST_CR_KEY_EXCH_A;
}
#else
} else
skip = 1;
s->state = SSL3_ST_CR_KEY_EXCH_A;
#endif
s->init_num = 0;
break;
case SSL3_ST_CR_KEY_EXCH_A:
case SSL3_ST_CR_KEY_EXCH_B:
ret = ssl3_get_key_exchange(s);
if (ret <= 0)
goto end;
s->state = SSL3_ST_CR_CERT_REQ_A;
s->init_num = 0;
/*
* at this point we check that we have the required stuff from
* the server
*/
if (!ssl3_check_cert_and_algorithm(s)) {
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
break;
case SSL3_ST_CR_CERT_REQ_A:
case SSL3_ST_CR_CERT_REQ_B:
ret = ssl3_get_certificate_request(s);
if (ret <= 0)
goto end;
s->state = SSL3_ST_CR_SRVR_DONE_A;
s->init_num = 0;
break;
case SSL3_ST_CR_SRVR_DONE_A:
case SSL3_ST_CR_SRVR_DONE_B:
ret = ssl3_get_server_done(s);
if (ret <= 0)
goto end;
dtls1_stop_timer(s);
if (s->s3->tmp.cert_req)
s->s3->tmp.next_state = SSL3_ST_CW_CERT_A;
else
s->s3->tmp.next_state = SSL3_ST_CW_KEY_EXCH_A;
s->init_num = 0;
#ifndef OPENSSL_NO_SCTP
if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
state == SSL_ST_RENEGOTIATE)
s->state = DTLS1_SCTP_ST_CR_READ_SOCK;
else
#endif
s->state = s->s3->tmp.next_state;
break;
case SSL3_ST_CW_CERT_A:
case SSL3_ST_CW_CERT_B:
case SSL3_ST_CW_CERT_C:
case SSL3_ST_CW_CERT_D:
dtls1_start_timer(s);
ret = dtls1_send_client_certificate(s);
if (ret <= 0)
goto end;
s->state = SSL3_ST_CW_KEY_EXCH_A;
s->init_num = 0;
break;
case SSL3_ST_CW_KEY_EXCH_A:
case SSL3_ST_CW_KEY_EXCH_B:
dtls1_start_timer(s);
ret = dtls1_send_client_key_exchange(s);
if (ret <= 0)
goto end;
#ifndef OPENSSL_NO_SCTP
/*
* Add new shared key for SCTP-Auth, will be ignored if no SCTP
* used.
*/
snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
DTLS1_SCTP_AUTH_LABEL);
if (SSL_export_keying_material(s, sctpauthkey,
sizeof(sctpauthkey), labelbuffer,
sizeof(labelbuffer), NULL, 0, 0) <= 0) {
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
sizeof(sctpauthkey), sctpauthkey);
#endif
/*
* EAY EAY EAY need to check for DH fix cert sent back
*/
/*
* For TLS, cert_req is set to 2, so a cert chain of nothing is
* sent, but no verify packet is sent
*/
if (s->s3->tmp.cert_req == 1) {
s->state = SSL3_ST_CW_CERT_VRFY_A;
} else {
#ifndef OPENSSL_NO_SCTP
if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
s->d1->next_state = SSL3_ST_CW_CHANGE_A;
s->state = DTLS1_SCTP_ST_CW_WRITE_SOCK;
} else
#endif
s->state = SSL3_ST_CW_CHANGE_A;
}
s->init_num = 0;
break;
case SSL3_ST_CW_CERT_VRFY_A:
case SSL3_ST_CW_CERT_VRFY_B:
dtls1_start_timer(s);
ret = dtls1_send_client_verify(s);
if (ret <= 0)
goto end;
#ifndef OPENSSL_NO_SCTP
if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
s->d1->next_state = SSL3_ST_CW_CHANGE_A;
s->state = DTLS1_SCTP_ST_CW_WRITE_SOCK;
} else
#endif
s->state = SSL3_ST_CW_CHANGE_A;
s->init_num = 0;
break;
case SSL3_ST_CW_CHANGE_A:
case SSL3_ST_CW_CHANGE_B:
if (!s->hit)
dtls1_start_timer(s);
ret = dtls1_send_change_cipher_spec(s,
SSL3_ST_CW_CHANGE_A,
SSL3_ST_CW_CHANGE_B);
if (ret <= 0)
goto end;
s->state = SSL3_ST_CW_FINISHED_A;
s->init_num = 0;
s->session->cipher = s->s3->tmp.new_cipher;
#ifdef OPENSSL_NO_COMP
s->session->compress_meth = 0;
#else
if (s->s3->tmp.new_compression == NULL)
s->session->compress_meth = 0;
else
s->session->compress_meth = s->s3->tmp.new_compression->id;
#endif
if (!s->method->ssl3_enc->setup_key_block(s)) {
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
if (!s->method->ssl3_enc->change_cipher_state(s,
SSL3_CHANGE_CIPHER_CLIENT_WRITE))
{
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
#ifndef OPENSSL_NO_SCTP
if (s->hit) {
/*
* Change to new shared key of SCTP-Auth, will be ignored if
* no SCTP used.
*/
BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
0, NULL);
}
#endif
dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
break;
case SSL3_ST_CW_FINISHED_A:
case SSL3_ST_CW_FINISHED_B:
if (!s->hit)
dtls1_start_timer(s);
ret = dtls1_send_finished(s,
SSL3_ST_CW_FINISHED_A,
SSL3_ST_CW_FINISHED_B,
s->method->
ssl3_enc->client_finished_label,
s->method->
ssl3_enc->client_finished_label_len);
if (ret <= 0)
goto end;
s->state = SSL3_ST_CW_FLUSH;
/* clear flags */
s->s3->flags &= ~SSL3_FLAGS_POP_BUFFER;
if (s->hit) {
s->s3->tmp.next_state = SSL_ST_OK;
#ifndef OPENSSL_NO_SCTP
if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
s->d1->next_state = s->s3->tmp.next_state;
s->s3->tmp.next_state = DTLS1_SCTP_ST_CW_WRITE_SOCK;
}
#endif
if (s->s3->flags & SSL3_FLAGS_DELAY_CLIENT_FINISHED) {
s->state = SSL_ST_OK;
#ifndef OPENSSL_NO_SCTP
if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
s->d1->next_state = SSL_ST_OK;
s->state = DTLS1_SCTP_ST_CW_WRITE_SOCK;
}
#endif
s->s3->flags |= SSL3_FLAGS_POP_BUFFER;
s->s3->delay_buf_pop_ret = 0;
}
} else {
#ifndef OPENSSL_NO_SCTP
/*
* Change to new shared key of SCTP-Auth, will be ignored if
* no SCTP used.
*/
BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
0, NULL);
#endif
#ifndef OPENSSL_NO_TLSEXT
/*
* Allow NewSessionTicket if ticket expected
*/
if (s->tlsext_ticket_expected)
s->s3->tmp.next_state = SSL3_ST_CR_SESSION_TICKET_A;
else
#endif
s->s3->tmp.next_state = SSL3_ST_CR_FINISHED_A;
}
s->init_num = 0;
break;
#ifndef OPENSSL_NO_TLSEXT
case SSL3_ST_CR_SESSION_TICKET_A:
case SSL3_ST_CR_SESSION_TICKET_B:
ret = ssl3_get_new_session_ticket(s);
if (ret <= 0)
goto end;
s->state = SSL3_ST_CR_FINISHED_A;
s->init_num = 0;
break;
case SSL3_ST_CR_CERT_STATUS_A:
case SSL3_ST_CR_CERT_STATUS_B:
ret = ssl3_get_cert_status(s);
if (ret <= 0)
goto end;
s->state = SSL3_ST_CR_KEY_EXCH_A;
s->init_num = 0;
break;
#endif
case SSL3_ST_CR_FINISHED_A:
case SSL3_ST_CR_FINISHED_B:
s->d1->change_cipher_spec_ok = 1;
ret = ssl3_get_finished(s, SSL3_ST_CR_FINISHED_A,
SSL3_ST_CR_FINISHED_B);
if (ret <= 0)
goto end;
dtls1_stop_timer(s);
if (s->hit)
s->state = SSL3_ST_CW_CHANGE_A;
else
s->state = SSL_ST_OK;
#ifndef OPENSSL_NO_SCTP
if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
state == SSL_ST_RENEGOTIATE) {
s->d1->next_state = s->state;
s->state = DTLS1_SCTP_ST_CW_WRITE_SOCK;
}
#endif
s->init_num = 0;
break;
case SSL3_ST_CW_FLUSH:
s->rwstate = SSL_WRITING;
if (BIO_flush(s->wbio) <= 0) {
/*
* If the write error was fatal, stop trying
*/
if (!BIO_should_retry(s->wbio)) {
s->rwstate = SSL_NOTHING;
s->state = s->s3->tmp.next_state;
}
ret = -1;
goto end;
}
s->rwstate = SSL_NOTHING;
s->state = s->s3->tmp.next_state;
break;
case SSL_ST_OK:
/* clean a few things up */
ssl3_cleanup_key_block(s);
#if 0
if (s->init_buf != NULL) {
BUF_MEM_free(s->init_buf);
s->init_buf = NULL;
}
#endif
/*
* If we are not 'joining' the last two packets, remove the
* buffering now
*/
if (!(s->s3->flags & SSL3_FLAGS_POP_BUFFER))
ssl_free_wbio_buffer(s);
/* else do it later in ssl3_write */
s->init_num = 0;
s->renegotiate = 0;
s->new_session = 0;
ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
if (s->hit)
s->ctx->stats.sess_hit++;
ret = 1;
/* s->server=0; */
s->handshake_func = dtls1_connect;
s->ctx->stats.sess_connect_good++;
if (cb != NULL)
cb(s, SSL_CB_HANDSHAKE_DONE, 1);
/* done with handshaking */
s->d1->handshake_read_seq = 0;
s->d1->next_handshake_write_seq = 0;
dtls1_clear_received_buffer(s);
goto end;
/* break; */
case SSL_ST_ERR:
default:
SSLerr(SSL_F_DTLS1_CONNECT, SSL_R_UNKNOWN_STATE);
ret = -1;
goto end;
/* break; */
}
/* did we do anything */
if (!s->s3->tmp.reuse_message && !skip) {
if (s->debug) {
if ((ret = BIO_flush(s->wbio)) <= 0)
goto end;
}
if ((cb != NULL) && (s->state != state)) {
new_state = s->state;
s->state = state;
cb(s, SSL_CB_CONNECT_LOOP, 1);
s->state = new_state;
}
}
skip = 0;
}
end:
s->in_handshake--;
#ifndef OPENSSL_NO_SCTP
/*
* Notify SCTP BIO socket to leave handshake mode and allow stream
* identifier other than 0. Will be ignored if no SCTP is used.
*/
BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
s->in_handshake, NULL);
#endif
if (buf != NULL)
BUF_MEM_free(buf);
if (cb != NULL)
cb(s, SSL_CB_CONNECT_EXIT, ret);
return (ret);
}
int dtls1_client_hello(SSL *s)
{
unsigned char *buf;
unsigned char *p, *d;
unsigned int i, j;
unsigned long l;
SSL_COMP *comp;
buf = (unsigned char *)s->init_buf->data;
if (s->state == SSL3_ST_CW_CLNT_HELLO_A) {
SSL_SESSION *sess = s->session;
if ((s->session == NULL) || (s->session->ssl_version != s->version) ||
#ifdef OPENSSL_NO_TLSEXT
!sess->session_id_length ||
#else
(!sess->session_id_length && !sess->tlsext_tick) ||
#endif
(s->session->not_resumable)) {
if (!ssl_get_new_session(s, 0))
goto err;
}
/* else use the pre-loaded session */
p = s->s3->client_random;
/*
* if client_random is initialized, reuse it, we are required to use
* same upon reply to HelloVerify
*/
for (i = 0; p[i] == '\0' && i < sizeof(s->s3->client_random); i++) ;
if (i == sizeof(s->s3->client_random))
ssl_fill_hello_random(s, 0, p, sizeof(s->s3->client_random));
/* Do the message type and length last */
d = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
*(p++) = s->version >> 8;
*(p++) = s->version & 0xff;
s->client_version = s->version;
/* Random stuff */
memcpy(p, s->s3->client_random, SSL3_RANDOM_SIZE);
p += SSL3_RANDOM_SIZE;
/* Session ID */
if (s->new_session)
i = 0;
else
i = s->session->session_id_length;
*(p++) = i;
if (i != 0) {
if (i > sizeof s->session->session_id) {
SSLerr(SSL_F_DTLS1_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
goto err;
}
memcpy(p, s->session->session_id, i);
p += i;
}
/* cookie stuff */
if (s->d1->cookie_len > sizeof(s->d1->cookie)) {
SSLerr(SSL_F_DTLS1_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
goto err;
}
*(p++) = s->d1->cookie_len;
memcpy(p, s->d1->cookie, s->d1->cookie_len);
p += s->d1->cookie_len;
/* Ciphers supported */
i = ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), &(p[2]), 0);
if (i == 0) {
SSLerr(SSL_F_DTLS1_CLIENT_HELLO, SSL_R_NO_CIPHERS_AVAILABLE);
goto err;
}
s2n(i, p);
p += i;
/* COMPRESSION */
if (s->ctx->comp_methods == NULL)
j = 0;
else
j = sk_SSL_COMP_num(s->ctx->comp_methods);
*(p++) = 1 + j;
for (i = 0; i < j; i++) {
comp = sk_SSL_COMP_value(s->ctx->comp_methods, i);
*(p++) = comp->id;
}
*(p++) = 0; /* Add the NULL method */
#ifndef OPENSSL_NO_TLSEXT
/* TLS extensions */
if (ssl_prepare_clienthello_tlsext(s) <= 0) {
SSLerr(SSL_F_DTLS1_CLIENT_HELLO, SSL_R_CLIENTHELLO_TLSEXT);
goto err;
}
if ((p =
ssl_add_clienthello_tlsext(s, p,
buf + SSL3_RT_MAX_PLAIN_LENGTH)) ==
NULL) {
SSLerr(SSL_F_DTLS1_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
goto err;
}
#endif
l = (p - d);
d = buf;
d = dtls1_set_message_header(s, d, SSL3_MT_CLIENT_HELLO, l, 0, l);
s->state = SSL3_ST_CW_CLNT_HELLO_B;
/* number of bytes to write */
s->init_num = p - buf;
s->init_off = 0;
/* buffer the message to handle re-xmits */
dtls1_buffer_message(s, 0);
}
/* SSL3_ST_CW_CLNT_HELLO_B */
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
err:
return (-1);
}
static int dtls1_get_hello_verify(SSL *s)
{
int n, al, ok = 0;
unsigned char *data;
unsigned int cookie_len;
n = s->method->ssl_get_message(s,
DTLS1_ST_CR_HELLO_VERIFY_REQUEST_A,
DTLS1_ST_CR_HELLO_VERIFY_REQUEST_B,
-1, s->max_cert_list, &ok);
if (!ok)
return ((int)n);
if (s->s3->tmp.message_type != DTLS1_MT_HELLO_VERIFY_REQUEST) {
s->d1->send_cookie = 0;
s->s3->tmp.reuse_message = 1;
return (1);
}
data = (unsigned char *)s->init_msg;
if ((data[0] != (s->version >> 8)) || (data[1] != (s->version & 0xff))) {
SSLerr(SSL_F_DTLS1_GET_HELLO_VERIFY, SSL_R_WRONG_SSL_VERSION);
s->version = (s->version & 0xff00) | data[1];
al = SSL_AD_PROTOCOL_VERSION;
goto f_err;
}
data += 2;
cookie_len = *(data++);
if (cookie_len > sizeof(s->d1->cookie)) {
al = SSL_AD_ILLEGAL_PARAMETER;
goto f_err;
}
memcpy(s->d1->cookie, data, cookie_len);
s->d1->cookie_len = cookie_len;
s->d1->send_cookie = 1;
return 1;
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
s->state = SSL_ST_ERR;
return -1;
}
int dtls1_send_client_key_exchange(SSL *s)
{
unsigned char *p, *d;
int n;
unsigned long alg_k;
#ifndef OPENSSL_NO_RSA
unsigned char *q;
EVP_PKEY *pkey = NULL;
#endif
#ifndef OPENSSL_NO_KRB5
KSSL_ERR kssl_err;
#endif /* OPENSSL_NO_KRB5 */
#ifndef OPENSSL_NO_ECDH
EC_KEY *clnt_ecdh = NULL;
const EC_POINT *srvr_ecpoint = NULL;
EVP_PKEY *srvr_pub_pkey = NULL;
unsigned char *encodedPoint = NULL;
int encoded_pt_len = 0;
BN_CTX *bn_ctx = NULL;
#endif
if (s->state == SSL3_ST_CW_KEY_EXCH_A) {
d = (unsigned char *)s->init_buf->data;
p = &(d[DTLS1_HM_HEADER_LENGTH]);
alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
/* Fool emacs indentation */
if (0) {
}
#ifndef OPENSSL_NO_RSA
else if (alg_k & SSL_kRSA) {
RSA *rsa;
unsigned char tmp_buf[SSL_MAX_MASTER_KEY_LENGTH];
if (s->session->sess_cert == NULL) {
/*
* We should always have a server certificate with SSL_kRSA.
*/
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_INTERNAL_ERROR);
goto err;
}
if (s->session->sess_cert->peer_rsa_tmp != NULL)
rsa = s->session->sess_cert->peer_rsa_tmp;
else {
pkey =
X509_get_pubkey(s->session->
sess_cert->peer_pkeys[SSL_PKEY_RSA_ENC].
x509);
if ((pkey == NULL) || (pkey->type != EVP_PKEY_RSA)
|| (pkey->pkey.rsa == NULL)) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_INTERNAL_ERROR);
goto err;
}
rsa = pkey->pkey.rsa;
EVP_PKEY_free(pkey);
}
tmp_buf[0] = s->client_version >> 8;
tmp_buf[1] = s->client_version & 0xff;
if (RAND_bytes(&(tmp_buf[2]), sizeof tmp_buf - 2) <= 0)
goto err;
s->session->master_key_length = sizeof tmp_buf;
q = p;
/* Fix buf for TLS and [incidentally] DTLS */
if (s->version > SSL3_VERSION)
p += 2;
n = RSA_public_encrypt(sizeof tmp_buf,
tmp_buf, p, rsa, RSA_PKCS1_PADDING);
# ifdef PKCS1_CHECK
if (s->options & SSL_OP_PKCS1_CHECK_1)
p[1]++;
if (s->options & SSL_OP_PKCS1_CHECK_2)
tmp_buf[0] = 0x70;
# endif
if (n <= 0) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
SSL_R_BAD_RSA_ENCRYPT);
goto err;
}
/* Fix buf for TLS and [incidentally] DTLS */
if (s->version > SSL3_VERSION) {
s2n(n, q);
n += 2;
}
s->session->master_key_length =
s->method->ssl3_enc->generate_master_secret(s,
s->
session->master_key,
tmp_buf,
sizeof tmp_buf);
OPENSSL_cleanse(tmp_buf, sizeof tmp_buf);
}
#endif
#ifndef OPENSSL_NO_KRB5
else if (alg_k & SSL_kKRB5) {
krb5_error_code krb5rc;
KSSL_CTX *kssl_ctx = s->kssl_ctx;
/* krb5_data krb5_ap_req; */
krb5_data *enc_ticket;
krb5_data authenticator, *authp = NULL;
EVP_CIPHER_CTX ciph_ctx;
const EVP_CIPHER *enc = NULL;
unsigned char iv[EVP_MAX_IV_LENGTH];
unsigned char tmp_buf[SSL_MAX_MASTER_KEY_LENGTH];
unsigned char epms[SSL_MAX_MASTER_KEY_LENGTH + EVP_MAX_IV_LENGTH];
int padl, outl = sizeof(epms);
EVP_CIPHER_CTX_init(&ciph_ctx);
# ifdef KSSL_DEBUG
printf("ssl3_send_client_key_exchange(%lx & %lx)\n",
alg_k, SSL_kKRB5);
# endif /* KSSL_DEBUG */
authp = NULL;
# ifdef KRB5SENDAUTH
if (KRB5SENDAUTH)
authp = &authenticator;
# endif /* KRB5SENDAUTH */
krb5rc = kssl_cget_tkt(kssl_ctx, &enc_ticket, authp, &kssl_err);
enc = kssl_map_enc(kssl_ctx->enctype);
if (enc == NULL)
goto err;
# ifdef KSSL_DEBUG
{
printf("kssl_cget_tkt rtn %d\n", krb5rc);
if (krb5rc && kssl_err.text)
printf("kssl_cget_tkt kssl_err=%s\n", kssl_err.text);
}
# endif /* KSSL_DEBUG */
if (krb5rc) {
ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE, kssl_err.reason);
goto err;
}
/*-
* 20010406 VRS - Earlier versions used KRB5 AP_REQ
** in place of RFC 2712 KerberosWrapper, as in:
**
** Send ticket (copy to *p, set n = length)
** n = krb5_ap_req.length;
** memcpy(p, krb5_ap_req.data, krb5_ap_req.length);
** if (krb5_ap_req.data)
** kssl_krb5_free_data_contents(NULL,&krb5_ap_req);
**
** Now using real RFC 2712 KerberosWrapper
** (Thanks to Simon Wilkinson <sxw@sxw.org.uk>)
** Note: 2712 "opaque" types are here replaced
** with a 2-byte length followed by the value.
** Example:
** KerberosWrapper= xx xx asn1ticket 0 0 xx xx encpms
** Where "xx xx" = length bytes. Shown here with
** optional authenticator omitted.
*/
/* KerberosWrapper.Ticket */
s2n(enc_ticket->length, p);
memcpy(p, enc_ticket->data, enc_ticket->length);
p += enc_ticket->length;
n = enc_ticket->length + 2;
/* KerberosWrapper.Authenticator */
if (authp && authp->length) {
s2n(authp->length, p);
memcpy(p, authp->data, authp->length);
p += authp->length;
n += authp->length + 2;
free(authp->data);
authp->data = NULL;
authp->length = 0;
} else {
s2n(0, p); /* null authenticator length */
n += 2;
}
if (RAND_bytes(tmp_buf, sizeof tmp_buf) <= 0)
goto err;
/*-
* 20010420 VRS. Tried it this way; failed.
* EVP_EncryptInit_ex(&ciph_ctx,enc, NULL,NULL);
* EVP_CIPHER_CTX_set_key_length(&ciph_ctx,
* kssl_ctx->length);
* EVP_EncryptInit_ex(&ciph_ctx,NULL, key,iv);
*/
memset(iv, 0, sizeof iv); /* per RFC 1510 */
EVP_EncryptInit_ex(&ciph_ctx, enc, NULL, kssl_ctx->key, iv);
EVP_EncryptUpdate(&ciph_ctx, epms, &outl, tmp_buf,
sizeof tmp_buf);
EVP_EncryptFinal_ex(&ciph_ctx, &(epms[outl]), &padl);
outl += padl;
if (outl > (int)sizeof epms) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_INTERNAL_ERROR);
goto err;
}
EVP_CIPHER_CTX_cleanup(&ciph_ctx);
/* KerberosWrapper.EncryptedPreMasterSecret */
s2n(outl, p);
memcpy(p, epms, outl);
p += outl;
n += outl + 2;
s->session->master_key_length =
s->method->ssl3_enc->generate_master_secret(s,
s->
session->master_key,
tmp_buf,
sizeof tmp_buf);
OPENSSL_cleanse(tmp_buf, sizeof tmp_buf);
OPENSSL_cleanse(epms, outl);
}
#endif
#ifndef OPENSSL_NO_DH
else if (alg_k & (SSL_kEDH | SSL_kDHr | SSL_kDHd)) {
DH *dh_srvr, *dh_clnt;
if (s->session->sess_cert == NULL) {
ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
SSL_R_UNEXPECTED_MESSAGE);
goto err;
}
if (s->session->sess_cert->peer_dh_tmp != NULL)
dh_srvr = s->session->sess_cert->peer_dh_tmp;
else {
/* we get them from the cert */
ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
SSL_R_UNABLE_TO_FIND_DH_PARAMETERS);
goto err;
}
/* generate a new random key */
if ((dh_clnt = DHparams_dup(dh_srvr)) == NULL) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE, ERR_R_DH_LIB);
goto err;
}
if (!DH_generate_key(dh_clnt)) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE, ERR_R_DH_LIB);
goto err;
}
/*
* use the 'p' output buffer for the DH key, but make sure to
* clear it out afterwards
*/
n = DH_compute_key(p, dh_srvr->pub_key, dh_clnt);
if (n <= 0) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE, ERR_R_DH_LIB);
goto err;
}
/* generate master key from the result */
s->session->master_key_length =
s->method->ssl3_enc->generate_master_secret(s,
s->
session->master_key,
p, n);
/* clean up */
memset(p, 0, n);
/* send off the data */
n = BN_num_bytes(dh_clnt->pub_key);
s2n(n, p);
BN_bn2bin(dh_clnt->pub_key, p);
n += 2;
DH_free(dh_clnt);
/* perhaps clean things up a bit EAY EAY EAY EAY */
}
#endif
#ifndef OPENSSL_NO_ECDH
else if (alg_k & (SSL_kEECDH | SSL_kECDHr | SSL_kECDHe)) {
const EC_GROUP *srvr_group = NULL;
EC_KEY *tkey;
int ecdh_clnt_cert = 0;
int field_size = 0;
if (s->session->sess_cert == NULL) {
ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
SSL_R_UNEXPECTED_MESSAGE);
goto err;
}
/*
* Did we send out the client's ECDH share for use in premaster
* computation as part of client certificate? If so, set
* ecdh_clnt_cert to 1.
*/
if ((alg_k & (SSL_kECDHr | SSL_kECDHe)) && (s->cert != NULL)) {
/*
* XXX: For now, we do not support client authentication
* using ECDH certificates. To add such support, one needs to
* add code that checks for appropriate conditions and sets
* ecdh_clnt_cert to 1. For example, the cert have an ECC key
* on the same curve as the server's and the key should be
* authorized for key agreement. One also needs to add code
* in ssl3_connect to skip sending the certificate verify
* message. if ((s->cert->key->privatekey != NULL) &&
* (s->cert->key->privatekey->type == EVP_PKEY_EC) && ...)
* ecdh_clnt_cert = 1;
*/
}
if (s->session->sess_cert->peer_ecdh_tmp != NULL) {
tkey = s->session->sess_cert->peer_ecdh_tmp;
} else {
/* Get the Server Public Key from Cert */
srvr_pub_pkey =
X509_get_pubkey(s->session->
sess_cert->peer_pkeys[SSL_PKEY_ECC].x509);
if ((srvr_pub_pkey == NULL)
|| (srvr_pub_pkey->type != EVP_PKEY_EC)
|| (srvr_pub_pkey->pkey.ec == NULL)) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_INTERNAL_ERROR);
goto err;
}
tkey = srvr_pub_pkey->pkey.ec;
}
srvr_group = EC_KEY_get0_group(tkey);
srvr_ecpoint = EC_KEY_get0_public_key(tkey);
if ((srvr_group == NULL) || (srvr_ecpoint == NULL)) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_INTERNAL_ERROR);
goto err;
}
if ((clnt_ecdh = EC_KEY_new()) == NULL) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_MALLOC_FAILURE);
goto err;
}
if (!EC_KEY_set_group(clnt_ecdh, srvr_group)) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE, ERR_R_EC_LIB);
goto err;
}
if (ecdh_clnt_cert) {
/*
* Reuse key info from our certificate We only need our
* private key to perform the ECDH computation.
*/
const BIGNUM *priv_key;
tkey = s->cert->key->privatekey->pkey.ec;
priv_key = EC_KEY_get0_private_key(tkey);
if (priv_key == NULL) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_MALLOC_FAILURE);
goto err;
}
if (!EC_KEY_set_private_key(clnt_ecdh, priv_key)) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_EC_LIB);
goto err;
}
} else {
/* Generate a new ECDH key pair */
if (!(EC_KEY_generate_key(clnt_ecdh))) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_ECDH_LIB);
goto err;
}
}
/*
* use the 'p' output buffer for the ECDH key, but make sure to
* clear it out afterwards
*/
field_size = EC_GROUP_get_degree(srvr_group);
if (field_size <= 0) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE, ERR_R_ECDH_LIB);
goto err;
}
n = ECDH_compute_key(p, (field_size + 7) / 8, srvr_ecpoint,
clnt_ecdh, NULL);
if (n <= 0) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE, ERR_R_ECDH_LIB);
goto err;
}
/* generate master key from the result */
s->session->master_key_length =
s->method->ssl3_enc->generate_master_secret(s,
s->
session->master_key,
p, n);
memset(p, 0, n); /* clean up */
if (ecdh_clnt_cert) {
/* Send empty client key exch message */
n = 0;
} else {
/*
* First check the size of encoding and allocate memory
* accordingly.
*/
encoded_pt_len =
EC_POINT_point2oct(srvr_group,
EC_KEY_get0_public_key(clnt_ecdh),
POINT_CONVERSION_UNCOMPRESSED,
NULL, 0, NULL);
encodedPoint = (unsigned char *)
OPENSSL_malloc(encoded_pt_len * sizeof(unsigned char));
bn_ctx = BN_CTX_new();
if ((encodedPoint == NULL) || (bn_ctx == NULL)) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_MALLOC_FAILURE);
goto err;
}
/* Encode the public key */
n = EC_POINT_point2oct(srvr_group,
EC_KEY_get0_public_key(clnt_ecdh),
POINT_CONVERSION_UNCOMPRESSED,
encodedPoint, encoded_pt_len, bn_ctx);
*p = n; /* length of encoded point */
/* Encoded point will be copied here */
p += 1;
/* copy the point */
memcpy((unsigned char *)p, encodedPoint, n);
/* increment n to account for length field */
n += 1;
}
/* Free allocated memory */
BN_CTX_free(bn_ctx);
if (encodedPoint != NULL)
OPENSSL_free(encodedPoint);
if (clnt_ecdh != NULL)
EC_KEY_free(clnt_ecdh);
EVP_PKEY_free(srvr_pub_pkey);
}
#endif /* !OPENSSL_NO_ECDH */
#ifndef OPENSSL_NO_PSK
else if (alg_k & SSL_kPSK) {
char identity[PSK_MAX_IDENTITY_LEN];
unsigned char *t = NULL;
unsigned char psk_or_pre_ms[PSK_MAX_PSK_LEN * 2 + 4];
unsigned int pre_ms_len = 0, psk_len = 0;
int psk_err = 1;
n = 0;
if (s->psk_client_callback == NULL) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
SSL_R_PSK_NO_CLIENT_CB);
goto err;
}
psk_len = s->psk_client_callback(s, s->ctx->psk_identity_hint,
identity, PSK_MAX_IDENTITY_LEN,
psk_or_pre_ms,
sizeof(psk_or_pre_ms));
if (psk_len > PSK_MAX_PSK_LEN) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_INTERNAL_ERROR);
goto psk_err;
} else if (psk_len == 0) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
SSL_R_PSK_IDENTITY_NOT_FOUND);
goto psk_err;
}
/* create PSK pre_master_secret */
pre_ms_len = 2 + psk_len + 2 + psk_len;
t = psk_or_pre_ms;
memmove(psk_or_pre_ms + psk_len + 4, psk_or_pre_ms, psk_len);
s2n(psk_len, t);
memset(t, 0, psk_len);
t += psk_len;
s2n(psk_len, t);
if (s->session->psk_identity_hint != NULL)
OPENSSL_free(s->session->psk_identity_hint);
s->session->psk_identity_hint =
BUF_strdup(s->ctx->psk_identity_hint);
if (s->ctx->psk_identity_hint != NULL
&& s->session->psk_identity_hint == NULL) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_MALLOC_FAILURE);
goto psk_err;
}
if (s->session->psk_identity != NULL)
OPENSSL_free(s->session->psk_identity);
s->session->psk_identity = BUF_strdup(identity);
if (s->session->psk_identity == NULL) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_MALLOC_FAILURE);
goto psk_err;
}
s->session->master_key_length =
s->method->ssl3_enc->generate_master_secret(s,
s->
session->master_key,
psk_or_pre_ms,
pre_ms_len);
n = strlen(identity);
s2n(n, p);
memcpy(p, identity, n);
n += 2;
psk_err = 0;
psk_err:
OPENSSL_cleanse(identity, PSK_MAX_IDENTITY_LEN);
OPENSSL_cleanse(psk_or_pre_ms, sizeof(psk_or_pre_ms));
if (psk_err != 0) {
ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
goto err;
}
}
#endif
else {
ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,
ERR_R_INTERNAL_ERROR);
goto err;
}
d = dtls1_set_message_header(s, d,
SSL3_MT_CLIENT_KEY_EXCHANGE, n, 0, n);
/*-
*(d++)=SSL3_MT_CLIENT_KEY_EXCHANGE;
l2n3(n,d);
l2n(s->d1->handshake_write_seq,d);
s->d1->handshake_write_seq++;
*/
s->state = SSL3_ST_CW_KEY_EXCH_B;
/* number of bytes to write */
s->init_num = n + DTLS1_HM_HEADER_LENGTH;
s->init_off = 0;
/* buffer the message to handle re-xmits */
dtls1_buffer_message(s, 0);
}
/* SSL3_ST_CW_KEY_EXCH_B */
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
err:
#ifndef OPENSSL_NO_ECDH
BN_CTX_free(bn_ctx);
if (encodedPoint != NULL)
OPENSSL_free(encodedPoint);
if (clnt_ecdh != NULL)
EC_KEY_free(clnt_ecdh);
EVP_PKEY_free(srvr_pub_pkey);
#endif
return (-1);
}
int dtls1_send_client_verify(SSL *s)
{
unsigned char *p, *d;
unsigned char data[MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH];
EVP_PKEY *pkey;
#ifndef OPENSSL_NO_RSA
unsigned u = 0;
#endif
unsigned long n;
#if !defined(OPENSSL_NO_DSA) || !defined(OPENSSL_NO_ECDSA)
int j;
#endif
if (s->state == SSL3_ST_CW_CERT_VRFY_A) {
d = (unsigned char *)s->init_buf->data;
p = &(d[DTLS1_HM_HEADER_LENGTH]);
pkey = s->cert->key->privatekey;
s->method->ssl3_enc->cert_verify_mac(s,
NID_sha1,
&(data[MD5_DIGEST_LENGTH]));
#ifndef OPENSSL_NO_RSA
if (pkey->type == EVP_PKEY_RSA) {
s->method->ssl3_enc->cert_verify_mac(s, NID_md5, &(data[0]));
if (RSA_sign(NID_md5_sha1, data,
MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH,
&(p[2]), &u, pkey->pkey.rsa) <= 0) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_VERIFY, ERR_R_RSA_LIB);
goto err;
}
s2n(u, p);
n = u + 2;
} else
#endif
#ifndef OPENSSL_NO_DSA
if (pkey->type == EVP_PKEY_DSA) {
if (!DSA_sign(pkey->save_type,
&(data[MD5_DIGEST_LENGTH]),
SHA_DIGEST_LENGTH, &(p[2]),
(unsigned int *)&j, pkey->pkey.dsa)) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_VERIFY, ERR_R_DSA_LIB);
goto err;
}
s2n(j, p);
n = j + 2;
} else
#endif
#ifndef OPENSSL_NO_ECDSA
if (pkey->type == EVP_PKEY_EC) {
if (!ECDSA_sign(pkey->save_type,
&(data[MD5_DIGEST_LENGTH]),
SHA_DIGEST_LENGTH, &(p[2]),
(unsigned int *)&j, pkey->pkey.ec)) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_VERIFY, ERR_R_ECDSA_LIB);
goto err;
}
s2n(j, p);
n = j + 2;
} else
#endif
{
SSLerr(SSL_F_DTLS1_SEND_CLIENT_VERIFY, ERR_R_INTERNAL_ERROR);
goto err;
}
d = dtls1_set_message_header(s, d,
SSL3_MT_CERTIFICATE_VERIFY, n, 0, n);
s->init_num = (int)n + DTLS1_HM_HEADER_LENGTH;
s->init_off = 0;
/* buffer the message to handle re-xmits */
dtls1_buffer_message(s, 0);
s->state = SSL3_ST_CW_CERT_VRFY_B;
}
/* s->state = SSL3_ST_CW_CERT_VRFY_B */
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
err:
return (-1);
}
int dtls1_send_client_certificate(SSL *s)
{
X509 *x509 = NULL;
EVP_PKEY *pkey = NULL;
int i;
unsigned long l;
if (s->state == SSL3_ST_CW_CERT_A) {
if ((s->cert == NULL) ||
(s->cert->key->x509 == NULL) ||
(s->cert->key->privatekey == NULL))
s->state = SSL3_ST_CW_CERT_B;
else
s->state = SSL3_ST_CW_CERT_C;
}
/* We need to get a client cert */
if (s->state == SSL3_ST_CW_CERT_B) {
/*
* If we get an error, we need to ssl->rwstate=SSL_X509_LOOKUP;
* return(-1); We then get retied later
*/
i = 0;
i = ssl_do_client_cert_cb(s, &x509, &pkey);
if (i < 0) {
s->rwstate = SSL_X509_LOOKUP;
return (-1);
}
s->rwstate = SSL_NOTHING;
if ((i == 1) && (pkey != NULL) && (x509 != NULL)) {
s->state = SSL3_ST_CW_CERT_B;
if (!SSL_use_certificate(s, x509) || !SSL_use_PrivateKey(s, pkey))
i = 0;
} else if (i == 1) {
i = 0;
SSLerr(SSL_F_DTLS1_SEND_CLIENT_CERTIFICATE,
SSL_R_BAD_DATA_RETURNED_BY_CALLBACK);
}
if (x509 != NULL)
X509_free(x509);
if (pkey != NULL)
EVP_PKEY_free(pkey);
if (i == 0) {
if (s->version == SSL3_VERSION) {
s->s3->tmp.cert_req = 0;
ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_CERTIFICATE);
return (1);
} else {
s->s3->tmp.cert_req = 2;
}
}
/* Ok, we have a cert */
s->state = SSL3_ST_CW_CERT_C;
}
if (s->state == SSL3_ST_CW_CERT_C) {
s->state = SSL3_ST_CW_CERT_D;
l = dtls1_output_cert_chain(s,
(s->s3->tmp.cert_req ==
2) ? NULL : s->cert->key->x509);
if (!l) {
SSLerr(SSL_F_DTLS1_SEND_CLIENT_CERTIFICATE, ERR_R_INTERNAL_ERROR);
ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return 0;
}
s->init_num = (int)l;
s->init_off = 0;
/* set header called by dtls1_output_cert_chain() */
/* buffer the message to handle re-xmits */
dtls1_buffer_message(s, 0);
}
/* SSL3_ST_CW_CERT_D */
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
}
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