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openssl/ssl/d1_srvr.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_srvr.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"
#include <openssl/buffer.h>
#include <openssl/rand.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/x509.h>
#include <openssl/md5.h>
#include <openssl/bn.h>
#ifndef OPENSSL_NO_DH
# include <openssl/dh.h>
#endif
static const SSL_METHOD *dtls1_get_server_method(int ver);
static int dtls1_send_hello_verify_request(SSL *s);
static const SSL_METHOD *dtls1_get_server_method(int ver)
{
if (ver == DTLS1_VERSION)
return (DTLSv1_server_method());
else
return (NULL);
}
IMPLEMENT_dtls1_meth_func(DTLSv1_server_method,
dtls1_accept,
ssl_undefined_function, dtls1_get_server_method)
int dtls1_accept(SSL *s)
{
BUF_MEM *buf;
unsigned long Time = (unsigned long)time(NULL);
void (*cb) (const SSL *ssl, int type, int val) = NULL;
unsigned long alg_k;
int ret = -1;
int new_state, state, skip = 0;
int listen;
#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;
listen = s->d1->listen;
/* init things to blank */
s->in_handshake++;
if (!SSL_in_init(s) || SSL_in_before(s))
SSL_clear(s);
s->d1->listen = listen;
#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
if (s->cert == NULL) {
SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_NO_CERTIFICATE_SET);
return (-1);
}
#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_ACCEPT; */
case SSL_ST_BEFORE:
case SSL_ST_ACCEPT:
case SSL_ST_BEFORE | SSL_ST_ACCEPT:
case SSL_ST_OK | SSL_ST_ACCEPT:
s->server = 1;
if (cb != NULL)
cb(s, SSL_CB_HANDSHAKE_START, 1);
if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
return -1;
}
s->type = SSL_ST_ACCEPT;
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)) {
BUF_MEM_free(buf);
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
s->init_buf = buf;
}
if (!ssl3_setup_buffers(s)) {
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
s->init_num = 0;
s->d1->change_cipher_spec_ok = 0;
/*
* Should have been reset by ssl3_get_finished, too.
*/
s->s3->change_cipher_spec = 0;
if (s->state != SSL_ST_RENEGOTIATE) {
/*
* Ok, we now need to push on a buffering BIO so that the
* output is sent in a way that TCP likes :-) ...but not with
* SCTP :-)
*/
#ifndef OPENSSL_NO_SCTP
if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
#endif
if (!ssl_init_wbio_buffer(s, 1)) {
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
ssl3_init_finished_mac(s);
s->state = SSL3_ST_SR_CLNT_HELLO_A;
s->ctx->stats.sess_accept++;
} else if (!s->s3->send_connection_binding &&
!(s->options &
SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
/*
* Server attempting to renegotiate with client that doesn't
* support secure renegotiation.
*/
SSLerr(SSL_F_DTLS1_ACCEPT,
SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
ret = -1;
s->state = SSL_ST_ERR;
goto end;
} else {
/*
* s->state == SSL_ST_RENEGOTIATE, we will just send a
* HelloRequest
*/
s->ctx->stats.sess_accept_renegotiate++;
s->state = SSL3_ST_SW_HELLO_REQ_A;
}
break;
case SSL3_ST_SW_HELLO_REQ_A:
case SSL3_ST_SW_HELLO_REQ_B:
s->shutdown = 0;
dtls1_clear_sent_buffer(s);
dtls1_start_timer(s);
ret = dtls1_send_hello_request(s);
if (ret <= 0)
goto end;
s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
s->state = SSL3_ST_SW_FLUSH;
s->init_num = 0;
ssl3_init_finished_mac(s);
break;
case SSL3_ST_SW_HELLO_REQ_C:
s->state = SSL_ST_OK;
break;
case SSL3_ST_SR_CLNT_HELLO_A:
case SSL3_ST_SR_CLNT_HELLO_B:
case SSL3_ST_SR_CLNT_HELLO_C:
s->shutdown = 0;
ret = ssl3_get_client_hello(s);
if (ret <= 0)
goto end;
dtls1_stop_timer(s);
if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
else
s->state = SSL3_ST_SW_SRVR_HELLO_A;
s->init_num = 0;
/*
* Reflect ClientHello sequence to remain stateless while
* listening
*/
if (listen) {
memcpy(s->s3->write_sequence, s->s3->read_sequence,
sizeof(s->s3->write_sequence));
}
/* If we're just listening, stop here */
if (listen && s->state == SSL3_ST_SW_SRVR_HELLO_A) {
ret = 2;
s->d1->listen = 0;
/*
* Set expected sequence numbers to continue the handshake.
*/
s->d1->handshake_read_seq = 2;
s->d1->handshake_write_seq = 1;
s->d1->next_handshake_write_seq = 1;
goto end;
}
break;
case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
ret = dtls1_send_hello_verify_request(s);
if (ret <= 0)
goto end;
s->state = SSL3_ST_SW_FLUSH;
s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
/* HelloVerifyRequest resets Finished MAC */
if (s->version != DTLS1_BAD_VER)
ssl3_init_finished_mac(s);
break;
#ifndef OPENSSL_NO_SCTP
case DTLS1_SCTP_ST_SR_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 = SSL3_ST_SR_FINISHED_A;
break;
case DTLS1_SCTP_ST_SW_WRITE_SOCK:
ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
if (ret < 0)
goto end;
if (ret == 0) {
if (s->d1->next_state != SSL_ST_OK) {
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_SW_SRVR_HELLO_A:
case SSL3_ST_SW_SRVR_HELLO_B:
s->renegotiate = 2;
dtls1_start_timer(s);
ret = dtls1_send_server_hello(s);
if (ret <= 0)
goto end;
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
#ifndef OPENSSL_NO_TLSEXT
if (s->tlsext_ticket_expected)
s->state = SSL3_ST_SW_SESSION_TICKET_A;
else
s->state = SSL3_ST_SW_CHANGE_A;
#else
s->state = SSL3_ST_SW_CHANGE_A;
#endif
} else
s->state = SSL3_ST_SW_CERT_A;
s->init_num = 0;
break;
case SSL3_ST_SW_CERT_A:
case SSL3_ST_SW_CERT_B:
/* Check if it is anon DH or normal PSK */
if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
&& !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
dtls1_start_timer(s);
ret = dtls1_send_server_certificate(s);
if (ret <= 0)
goto end;
#ifndef OPENSSL_NO_TLSEXT
if (s->tlsext_status_expected)
s->state = SSL3_ST_SW_CERT_STATUS_A;
else
s->state = SSL3_ST_SW_KEY_EXCH_A;
} else {
skip = 1;
s->state = SSL3_ST_SW_KEY_EXCH_A;
}
#else
} else
skip = 1;
s->state = SSL3_ST_SW_KEY_EXCH_A;
#endif
s->init_num = 0;
break;
case SSL3_ST_SW_KEY_EXCH_A:
case SSL3_ST_SW_KEY_EXCH_B:
alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
/*
* clear this, it may get reset by
* send_server_key_exchange
*/
s->s3->tmp.use_rsa_tmp = 0;
/*
* only send if a DH key exchange or RSA but we have a sign only
* certificate
*/
if (0
/*
* PSK: send ServerKeyExchange if PSK identity hint if
* provided
*/
#ifndef OPENSSL_NO_PSK
|| ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
#endif
|| (alg_k & SSL_kEDH)
|| (alg_k & SSL_kEECDH)
|| ((alg_k & SSL_kRSA)
&& (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
|| (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
&& EVP_PKEY_size(s->cert->pkeys
[SSL_PKEY_RSA_ENC].privatekey) *
8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
)
)
)
) {
dtls1_start_timer(s);
ret = dtls1_send_server_key_exchange(s);
if (ret <= 0)
goto end;
} else
skip = 1;
s->state = SSL3_ST_SW_CERT_REQ_A;
s->init_num = 0;
break;
case SSL3_ST_SW_CERT_REQ_A:
case SSL3_ST_SW_CERT_REQ_B:
if ( /* don't request cert unless asked for it: */
!(s->verify_mode & SSL_VERIFY_PEER) ||
/*
* if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
* during re-negotiation:
*/
((s->session->peer != NULL) &&
(s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
/*
* never request cert in anonymous ciphersuites (see
* section "Certificate request" in SSL 3 drafts and in
* RFC 2246):
*/
((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
/*
* ... except when the application insists on
* verification (against the specs, but s3_clnt.c accepts
* this for SSL 3)
*/
!(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
/*
* never request cert in Kerberos ciphersuites
*/
(s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
/*
* With normal PSK Certificates and Certificate Requests
* are omitted
*/
|| (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
/* no cert request */
skip = 1;
s->s3->tmp.cert_request = 0;
s->state = SSL3_ST_SW_SRVR_DONE_A;
#ifndef OPENSSL_NO_SCTP
if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
}
#endif
} else {
s->s3->tmp.cert_request = 1;
dtls1_start_timer(s);
ret = dtls1_send_certificate_request(s);
if (ret <= 0)
goto end;
#ifndef NETSCAPE_HANG_BUG
s->state = SSL3_ST_SW_SRVR_DONE_A;
# ifndef OPENSSL_NO_SCTP
if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
}
# endif
#else
s->state = SSL3_ST_SW_FLUSH;
s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
# 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_SW_WRITE_SOCK;
}
# endif
#endif
s->init_num = 0;
}
break;
case SSL3_ST_SW_SRVR_DONE_A:
case SSL3_ST_SW_SRVR_DONE_B:
dtls1_start_timer(s);
ret = dtls1_send_server_done(s);
if (ret <= 0)
goto end;
s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
s->state = SSL3_ST_SW_FLUSH;
s->init_num = 0;
break;
case SSL3_ST_SW_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 SSL3_ST_SR_CERT_A:
case SSL3_ST_SR_CERT_B:
/* Check for second client hello (MS SGC) */
ret = ssl3_check_client_hello(s);
if (ret <= 0)
goto end;
if (ret == 2) {
dtls1_stop_timer(s);
s->state = SSL3_ST_SR_CLNT_HELLO_C;
} else {
if (s->s3->tmp.cert_request) {
ret = ssl3_get_client_certificate(s);
if (ret <= 0)
goto end;
}
s->init_num = 0;
s->state = SSL3_ST_SR_KEY_EXCH_A;
}
break;
case SSL3_ST_SR_KEY_EXCH_A:
case SSL3_ST_SR_KEY_EXCH_B:
ret = ssl3_get_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
s->state = SSL3_ST_SR_CERT_VRFY_A;
s->init_num = 0;
if (ret == 2) {
/*
* For the ECDH ciphersuites when the client sends its ECDH
* pub key in a certificate, the CertificateVerify message is
* not sent.
*/
s->state = SSL3_ST_SR_FINISHED_A;
s->init_num = 0;
} else {
s->state = SSL3_ST_SR_CERT_VRFY_A;
s->init_num = 0;
/*
* We need to get hashes here so if there is a client cert,
* it can be verified
*/
s->method->ssl3_enc->cert_verify_mac(s,
NID_md5,
&(s->s3->
tmp.cert_verify_md
[0]));
s->method->ssl3_enc->cert_verify_mac(s, NID_sha1,
&(s->s3->
tmp.cert_verify_md
[MD5_DIGEST_LENGTH]));
}
break;
case SSL3_ST_SR_CERT_VRFY_A:
case SSL3_ST_SR_CERT_VRFY_B:
ret = ssl3_get_cert_verify(s);
if (ret <= 0)
goto end;
#ifndef OPENSSL_NO_SCTP
if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
state == SSL_ST_RENEGOTIATE)
s->state = DTLS1_SCTP_ST_SR_READ_SOCK;
else
#endif
s->state = SSL3_ST_SR_FINISHED_A;
s->init_num = 0;
break;
case SSL3_ST_SR_FINISHED_A:
case SSL3_ST_SR_FINISHED_B:
/*
* Enable CCS. Receiving a CCS clears the flag, so make
* sure not to re-enable it to ban duplicates. This *should* be the
* first time we have received one - but we check anyway to be
* cautious.
* s->s3->change_cipher_spec is set when a CCS is
* processed in d1_pkt.c, and remains set until
* the client's Finished message is read.
*/
if (!s->s3->change_cipher_spec)
s->d1->change_cipher_spec_ok = 1;
ret = ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A,
SSL3_ST_SR_FINISHED_B);
if (ret <= 0)
goto end;
dtls1_stop_timer(s);
if (s->hit)
s->state = SSL_ST_OK;
#ifndef OPENSSL_NO_TLSEXT
else if (s->tlsext_ticket_expected)
s->state = SSL3_ST_SW_SESSION_TICKET_A;
#endif
else
s->state = SSL3_ST_SW_CHANGE_A;
s->init_num = 0;
break;
#ifndef OPENSSL_NO_TLSEXT
case SSL3_ST_SW_SESSION_TICKET_A:
case SSL3_ST_SW_SESSION_TICKET_B:
ret = dtls1_send_newsession_ticket(s);
if (ret <= 0)
goto end;
s->state = SSL3_ST_SW_CHANGE_A;
s->init_num = 0;
break;
case SSL3_ST_SW_CERT_STATUS_A:
case SSL3_ST_SW_CERT_STATUS_B:
ret = ssl3_send_cert_status(s);
if (ret <= 0)
goto end;
s->state = SSL3_ST_SW_KEY_EXCH_A;
s->init_num = 0;
break;
#endif
case SSL3_ST_SW_CHANGE_A:
case SSL3_ST_SW_CHANGE_B:
s->session->cipher = s->s3->tmp.new_cipher;
if (!s->method->ssl3_enc->setup_key_block(s)) {
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
ret = dtls1_send_change_cipher_spec(s,
SSL3_ST_SW_CHANGE_A,
SSL3_ST_SW_CHANGE_B);
if (ret <= 0)
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
s->state = SSL3_ST_SW_FINISHED_A;
s->init_num = 0;
if (!s->method->ssl3_enc->change_cipher_state(s,
SSL3_CHANGE_CIPHER_SERVER_WRITE))
{
ret = -1;
s->state = SSL_ST_ERR;
goto end;
}
dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
break;
case SSL3_ST_SW_FINISHED_A:
case SSL3_ST_SW_FINISHED_B:
ret = dtls1_send_finished(s,
SSL3_ST_SW_FINISHED_A,
SSL3_ST_SW_FINISHED_B,
s->method->
ssl3_enc->server_finished_label,
s->method->
ssl3_enc->server_finished_label_len);
if (ret <= 0)
goto end;
s->state = SSL3_ST_SW_FLUSH;
if (s->hit) {
s->s3->tmp.next_state = SSL3_ST_SR_FINISHED_A;
#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
} else {
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_SW_WRITE_SOCK;
}
#endif
}
s->init_num = 0;
break;
case SSL_ST_OK:
/* clean a few things up */
ssl3_cleanup_key_block(s);
#if 0
BUF_MEM_free(s->init_buf);
s->init_buf = NULL;
#endif
/* remove buffering on output */
ssl_free_wbio_buffer(s);
s->init_num = 0;
if (s->renegotiate == 2) { /* skipped if we just sent a
* HelloRequest */
s->renegotiate = 0;
s->new_session = 0;
ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
s->ctx->stats.sess_accept_good++;
/* s->server=1; */
s->handshake_func = dtls1_accept;
if (cb != NULL)
cb(s, SSL_CB_HANDSHAKE_DONE, 1);
}
ret = 1;
/* done handshaking, next message is client hello */
s->d1->handshake_read_seq = 0;
/* next message is server hello */
s->d1->handshake_write_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_ACCEPT, SSL_R_UNKNOWN_STATE);
ret = -1;
goto end;
/* break; */
}
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_ACCEPT_LOOP, 1);
s->state = new_state;
}
}
skip = 0;
}
end:
/* BIO_flush(s->wbio); */
s->in_handshake--;
#ifndef OPENSSL_NO_SCTP
/*
* Notify SCTP BIO socket to leave 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
if (cb != NULL)
cb(s, SSL_CB_ACCEPT_EXIT, ret);
return (ret);
}
int dtls1_send_hello_request(SSL *s)
{
unsigned char *p;
if (s->state == SSL3_ST_SW_HELLO_REQ_A) {
p = (unsigned char *)s->init_buf->data;
p = dtls1_set_message_header(s, p, SSL3_MT_HELLO_REQUEST, 0, 0, 0);
s->state = SSL3_ST_SW_HELLO_REQ_B;
/* number of bytes to write */
s->init_num = DTLS1_HM_HEADER_LENGTH;
s->init_off = 0;
/*
* no need to buffer this message, since there are no retransmit
* requests for it
*/
}
/* SSL3_ST_SW_HELLO_REQ_B */
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
}
int dtls1_send_hello_verify_request(SSL *s)
{
unsigned int msg_len;
unsigned char *msg, *buf, *p;
if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) {
buf = (unsigned char *)s->init_buf->data;
msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
*(p++) = s->version >> 8;
*(p++) = s->version & 0xFF;
if (s->ctx->app_gen_cookie_cb == NULL ||
s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
&(s->d1->cookie_len)) == 0) {
SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,
ERR_R_INTERNAL_ERROR);
s->state = SSL_ST_ERR;
return 0;
}
*(p++) = (unsigned char)s->d1->cookie_len;
memcpy(p, s->d1->cookie, s->d1->cookie_len);
p += s->d1->cookie_len;
msg_len = p - msg;
dtls1_set_message_header(s, buf,
DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0,
msg_len);
s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
/* number of bytes to write */
s->init_num = p - buf;
s->init_off = 0;
}
/* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
}
int dtls1_send_server_hello(SSL *s)
{
unsigned char *buf;
unsigned char *p, *d;
int i;
unsigned int sl;
unsigned long l;
if (s->state == SSL3_ST_SW_SRVR_HELLO_A) {
buf = (unsigned char *)s->init_buf->data;
p = s->s3->server_random;
ssl_fill_hello_random(s, 1, p, SSL3_RANDOM_SIZE);
/* Do the message type and length last */
d = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
*(p++) = s->version >> 8;
*(p++) = s->version & 0xff;
/* Random stuff */
memcpy(p, s->s3->server_random, SSL3_RANDOM_SIZE);
p += SSL3_RANDOM_SIZE;
/*
* now in theory we have 3 options to sending back the session id.
* If it is a re-use, we send back the old session-id, if it is a new
* session, we send back the new session-id or we send back a 0
* length session-id if we want it to be single use. Currently I will
* not implement the '0' length session-id 12-Jan-98 - I'll now
* support the '0' length stuff.
*/
if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER))
s->session->session_id_length = 0;
sl = s->session->session_id_length;
if (sl > sizeof s->session->session_id) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
return -1;
}
*(p++) = sl;
memcpy(p, s->session->session_id, sl);
p += sl;
/* put the cipher */
if (s->s3->tmp.new_cipher == NULL)
return -1;
i = ssl3_put_cipher_by_char(s->s3->tmp.new_cipher, p);
p += i;
/* put the compression method */
#ifdef OPENSSL_NO_COMP
*(p++) = 0;
#else
if (s->s3->tmp.new_compression == NULL)
*(p++) = 0;
else
*(p++) = s->s3->tmp.new_compression->id;
#endif
#ifndef OPENSSL_NO_TLSEXT
if (ssl_prepare_serverhello_tlsext(s) <= 0) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_HELLO, SSL_R_SERVERHELLO_TLSEXT);
return -1;
}
if ((p =
ssl_add_serverhello_tlsext(s, p,
buf + SSL3_RT_MAX_PLAIN_LENGTH)) ==
NULL) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
return -1;
}
#endif
/* do the header */
l = (p - d);
d = buf;
d = dtls1_set_message_header(s, d, SSL3_MT_SERVER_HELLO, l, 0, l);
s->state = SSL3_ST_SW_SRVR_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_SW_SRVR_HELLO_B */
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
}
int dtls1_send_server_done(SSL *s)
{
unsigned char *p;
if (s->state == SSL3_ST_SW_SRVR_DONE_A) {
p = (unsigned char *)s->init_buf->data;
/* do the header */
p = dtls1_set_message_header(s, p, SSL3_MT_SERVER_DONE, 0, 0, 0);
s->state = SSL3_ST_SW_SRVR_DONE_B;
/* number of bytes to write */
s->init_num = DTLS1_HM_HEADER_LENGTH;
s->init_off = 0;
/* buffer the message to handle re-xmits */
dtls1_buffer_message(s, 0);
}
/* SSL3_ST_SW_SRVR_DONE_B */
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
}
int dtls1_send_server_key_exchange(SSL *s)
{
#ifndef OPENSSL_NO_RSA
unsigned char *q;
int j, num;
RSA *rsa;
unsigned char md_buf[MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH];
unsigned int u;
#endif
#ifndef OPENSSL_NO_DH
DH *dh = NULL, *dhp;
#endif
#ifndef OPENSSL_NO_ECDH
EC_KEY *ecdh = NULL, *ecdhp;
unsigned char *encodedPoint = NULL;
int encodedlen = 0;
int curve_id = 0;
BN_CTX *bn_ctx = NULL;
#endif
EVP_PKEY *pkey;
unsigned char *p, *d;
int al, i;
unsigned long type;
int n;
CERT *cert;
BIGNUM *r[4];
int nr[4], kn;
BUF_MEM *buf;
EVP_MD_CTX md_ctx;
EVP_MD_CTX_init(&md_ctx);
if (s->state == SSL3_ST_SW_KEY_EXCH_A) {
type = s->s3->tmp.new_cipher->algorithm_mkey;
cert = s->cert;
buf = s->init_buf;
r[0] = r[1] = r[2] = r[3] = NULL;
n = 0;
#ifndef OPENSSL_NO_RSA
if (type & SSL_kRSA) {
rsa = cert->rsa_tmp;
if ((rsa == NULL) && (s->cert->rsa_tmp_cb != NULL)) {
rsa = s->cert->rsa_tmp_cb(s,
SSL_C_IS_EXPORT(s->s3->
tmp.new_cipher),
SSL_C_EXPORT_PKEYLENGTH(s->s3->
tmp.new_cipher));
if (rsa == NULL) {
al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
SSL_R_ERROR_GENERATING_TMP_RSA_KEY);
goto f_err;
}
RSA_up_ref(rsa);
cert->rsa_tmp = rsa;
}
if (rsa == NULL) {
al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
SSL_R_MISSING_TMP_RSA_KEY);
goto f_err;
}
r[0] = rsa->n;
r[1] = rsa->e;
s->s3->tmp.use_rsa_tmp = 1;
} else
#endif
#ifndef OPENSSL_NO_DH
if (type & SSL_kEDH) {
dhp = cert->dh_tmp;
if ((dhp == NULL) && (s->cert->dh_tmp_cb != NULL))
dhp = s->cert->dh_tmp_cb(s,
SSL_C_IS_EXPORT(s->s3->
tmp.new_cipher),
SSL_C_EXPORT_PKEYLENGTH(s->s3->
tmp.new_cipher));
if (dhp == NULL) {
al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
SSL_R_MISSING_TMP_DH_KEY);
goto f_err;
}
if (s->s3->tmp.dh != NULL) {
DH_free(dh);
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
ERR_R_INTERNAL_ERROR);
goto err;
}
if ((dh = DHparams_dup(dhp)) == NULL) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE, ERR_R_DH_LIB);
goto err;
}
s->s3->tmp.dh = dh;
if ((dhp->pub_key == NULL ||
dhp->priv_key == NULL ||
(s->options & SSL_OP_SINGLE_DH_USE))) {
if (!DH_generate_key(dh)) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
ERR_R_DH_LIB);
goto err;
}
} else {
dh->pub_key = BN_dup(dhp->pub_key);
dh->priv_key = BN_dup(dhp->priv_key);
if ((dh->pub_key == NULL) || (dh->priv_key == NULL)) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
ERR_R_DH_LIB);
goto err;
}
}
r[0] = dh->p;
r[1] = dh->g;
r[2] = dh->pub_key;
} else
#endif
#ifndef OPENSSL_NO_ECDH
if (type & SSL_kEECDH) {
const EC_GROUP *group;
ecdhp = cert->ecdh_tmp;
if ((ecdhp == NULL) && (s->cert->ecdh_tmp_cb != NULL)) {
ecdhp = s->cert->ecdh_tmp_cb(s,
SSL_C_IS_EXPORT(s->s3->
tmp.new_cipher),
SSL_C_EXPORT_PKEYLENGTH(s->
s3->tmp.new_cipher));
}
if (ecdhp == NULL) {
al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
SSL_R_MISSING_TMP_ECDH_KEY);
goto f_err;
}
if (s->s3->tmp.ecdh != NULL) {
EC_KEY_free(s->s3->tmp.ecdh);
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
ERR_R_INTERNAL_ERROR);
goto err;
}
/* Duplicate the ECDH structure. */
if (ecdhp == NULL) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE, ERR_R_ECDH_LIB);
goto err;
}
if ((ecdh = EC_KEY_dup(ecdhp)) == NULL) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE, ERR_R_ECDH_LIB);
goto err;
}
s->s3->tmp.ecdh = ecdh;
if ((EC_KEY_get0_public_key(ecdh) == NULL) ||
(EC_KEY_get0_private_key(ecdh) == NULL) ||
(s->options & SSL_OP_SINGLE_ECDH_USE)) {
if (!EC_KEY_generate_key(ecdh)) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
ERR_R_ECDH_LIB);
goto err;
}
}
if (((group = EC_KEY_get0_group(ecdh)) == NULL) ||
(EC_KEY_get0_public_key(ecdh) == NULL) ||
(EC_KEY_get0_private_key(ecdh) == NULL)) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE, ERR_R_ECDH_LIB);
goto err;
}
if (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher) &&
(EC_GROUP_get_degree(group) > 163)) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
SSL_R_ECGROUP_TOO_LARGE_FOR_CIPHER);
goto err;
}
/*
* XXX: For now, we only support ephemeral ECDH keys over named
* (not generic) curves. For supported named curves, curve_id is
* non-zero.
*/
if ((curve_id =
tls1_ec_nid2curve_id(EC_GROUP_get_curve_name(group)))
== 0) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
SSL_R_UNSUPPORTED_ELLIPTIC_CURVE);
goto err;
}
/*
* Encode the public key. First check the size of encoding and
* allocate memory accordingly.
*/
encodedlen = EC_POINT_point2oct(group,
EC_KEY_get0_public_key(ecdh),
POINT_CONVERSION_UNCOMPRESSED,
NULL, 0, NULL);
encodedPoint = (unsigned char *)
OPENSSL_malloc(encodedlen * sizeof(unsigned char));
bn_ctx = BN_CTX_new();
if ((encodedPoint == NULL) || (bn_ctx == NULL)) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
ERR_R_MALLOC_FAILURE);
goto err;
}
encodedlen = EC_POINT_point2oct(group,
EC_KEY_get0_public_key(ecdh),
POINT_CONVERSION_UNCOMPRESSED,
encodedPoint, encodedlen, bn_ctx);
if (encodedlen == 0) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE, ERR_R_ECDH_LIB);
goto err;
}
BN_CTX_free(bn_ctx);
bn_ctx = NULL;
/*
* XXX: For now, we only support named (not generic) curves in
* ECDH ephemeral key exchanges. In this situation, we need four
* additional bytes to encode the entire ServerECDHParams
* structure.
*/
n = 4 + encodedlen;
/*
* We'll generate the serverKeyExchange message explicitly so we
* can set these to NULLs
*/
r[0] = NULL;
r[1] = NULL;
r[2] = NULL;
r[3] = NULL;
} else
#endif /* !OPENSSL_NO_ECDH */
#ifndef OPENSSL_NO_PSK
if (type & SSL_kPSK) {
/*
* reserve size for record length and PSK identity hint
*/
n += 2 + strlen(s->ctx->psk_identity_hint);
} else
#endif /* !OPENSSL_NO_PSK */
{
al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE);
goto f_err;
}
for (i = 0; r[i] != NULL; i++) {
nr[i] = BN_num_bytes(r[i]);
n += 2 + nr[i];
}
if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
&& !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
if ((pkey = ssl_get_sign_pkey(s, s->s3->tmp.new_cipher, NULL))
== NULL) {
al = SSL_AD_DECODE_ERROR;
goto f_err;
}
kn = EVP_PKEY_size(pkey);
} else {
pkey = NULL;
kn = 0;
}
if (!BUF_MEM_grow_clean(buf, n + DTLS1_HM_HEADER_LENGTH + kn)) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE, ERR_LIB_BUF);
goto err;
}
d = (unsigned char *)s->init_buf->data;
p = &(d[DTLS1_HM_HEADER_LENGTH]);
for (i = 0; r[i] != NULL; i++) {
s2n(nr[i], p);
BN_bn2bin(r[i], p);
p += nr[i];
}
#ifndef OPENSSL_NO_ECDH
if (type & SSL_kEECDH) {
/*
* XXX: For now, we only support named (not generic) curves. In
* this situation, the serverKeyExchange message has: [1 byte
* CurveType], [2 byte CurveName] [1 byte length of encoded
* point], followed by the actual encoded point itself
*/
*p = NAMED_CURVE_TYPE;
p += 1;
*p = 0;
p += 1;
*p = curve_id;
p += 1;
*p = encodedlen;
p += 1;
memcpy((unsigned char *)p,
(unsigned char *)encodedPoint, encodedlen);
OPENSSL_free(encodedPoint);
encodedPoint = NULL;
p += encodedlen;
}
#endif
#ifndef OPENSSL_NO_PSK
if (type & SSL_kPSK) {
/* copy PSK identity hint */
s2n(strlen(s->ctx->psk_identity_hint), p);
strncpy((char *)p, s->ctx->psk_identity_hint,
strlen(s->ctx->psk_identity_hint));
p += strlen(s->ctx->psk_identity_hint);
}
#endif
/* not anonymous */
if (pkey != NULL) {
/*
* n is the length of the params, they start at
* &(d[DTLS1_HM_HEADER_LENGTH]) and p points to the space at the
* end.
*/
#ifndef OPENSSL_NO_RSA
if (pkey->type == EVP_PKEY_RSA) {
q = md_buf;
j = 0;
for (num = 2; num > 0; num--) {
EVP_DigestInit_ex(&md_ctx, (num == 2)
? s->ctx->md5 : s->ctx->sha1, NULL);
EVP_DigestUpdate(&md_ctx, &(s->s3->client_random[0]),
SSL3_RANDOM_SIZE);
EVP_DigestUpdate(&md_ctx, &(s->s3->server_random[0]),
SSL3_RANDOM_SIZE);
EVP_DigestUpdate(&md_ctx, &(d[DTLS1_HM_HEADER_LENGTH]),
n);
EVP_DigestFinal_ex(&md_ctx, q, (unsigned int *)&i);
q += i;
j += i;
}
if (RSA_sign(NID_md5_sha1, md_buf, j,
&(p[2]), &u, pkey->pkey.rsa) <= 0) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE, ERR_LIB_RSA);
goto err;
}
s2n(u, p);
n += u + 2;
} else
#endif
#if !defined(OPENSSL_NO_DSA)
if (pkey->type == EVP_PKEY_DSA) {
/* lets do DSS */
EVP_SignInit_ex(&md_ctx, EVP_dss1(), NULL);
EVP_SignUpdate(&md_ctx, &(s->s3->client_random[0]),
SSL3_RANDOM_SIZE);
EVP_SignUpdate(&md_ctx, &(s->s3->server_random[0]),
SSL3_RANDOM_SIZE);
EVP_SignUpdate(&md_ctx, &(d[DTLS1_HM_HEADER_LENGTH]), n);
if (!EVP_SignFinal(&md_ctx, &(p[2]),
(unsigned int *)&i, pkey)) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE, ERR_LIB_DSA);
goto err;
}
s2n(i, p);
n += i + 2;
} else
#endif
#if !defined(OPENSSL_NO_ECDSA)
if (pkey->type == EVP_PKEY_EC) {
/* let's do ECDSA */
EVP_SignInit_ex(&md_ctx, EVP_ecdsa(), NULL);
EVP_SignUpdate(&md_ctx, &(s->s3->client_random[0]),
SSL3_RANDOM_SIZE);
EVP_SignUpdate(&md_ctx, &(s->s3->server_random[0]),
SSL3_RANDOM_SIZE);
EVP_SignUpdate(&md_ctx, &(d[DTLS1_HM_HEADER_LENGTH]), n);
if (!EVP_SignFinal(&md_ctx, &(p[2]),
(unsigned int *)&i, pkey)) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
ERR_LIB_ECDSA);
goto err;
}
s2n(i, p);
n += i + 2;
} else
#endif
{
/* Is this error check actually needed? */
al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
SSL_R_UNKNOWN_PKEY_TYPE);
goto f_err;
}
}
d = dtls1_set_message_header(s, d,
SSL3_MT_SERVER_KEY_EXCHANGE, n, 0, n);
/*
* we should now have things packed up, so lets send it off
*/
s->init_num = 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_SW_KEY_EXCH_B;
EVP_MD_CTX_cleanup(&md_ctx);
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
err:
#ifndef OPENSSL_NO_ECDH
if (encodedPoint != NULL)
OPENSSL_free(encodedPoint);
BN_CTX_free(bn_ctx);
#endif
EVP_MD_CTX_cleanup(&md_ctx);
return (-1);
}
int dtls1_send_certificate_request(SSL *s)
{
unsigned char *p, *d;
int i, j, nl, off, n;
STACK_OF(X509_NAME) *sk = NULL;
X509_NAME *name;
BUF_MEM *buf;
unsigned int msg_len;
if (s->state == SSL3_ST_SW_CERT_REQ_A) {
buf = s->init_buf;
d = p = (unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
/* get the list of acceptable cert types */
p++;
n = ssl3_get_req_cert_type(s, p);
d[0] = n;
p += n;
n++;
off = n;
p += 2;
n += 2;
sk = SSL_get_client_CA_list(s);
nl = 0;
if (sk != NULL) {
for (i = 0; i < sk_X509_NAME_num(sk); i++) {
name = sk_X509_NAME_value(sk, i);
j = i2d_X509_NAME(name, NULL);
if (!BUF_MEM_grow_clean
(buf, DTLS1_HM_HEADER_LENGTH + n + j + 2)) {
SSLerr(SSL_F_DTLS1_SEND_CERTIFICATE_REQUEST,
ERR_R_BUF_LIB);
goto err;
}
p = (unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH + n]);
if (!(s->options & SSL_OP_NETSCAPE_CA_DN_BUG)) {
s2n(j, p);
i2d_X509_NAME(name, &p);
n += 2 + j;
nl += 2 + j;
} else {
d = p;
i2d_X509_NAME(name, &p);
j -= 2;
s2n(j, d);
j += 2;
n += j;
nl += j;
}
}
}
/* else no CA names */
p = (unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH + off]);
s2n(nl, p);
d = (unsigned char *)buf->data;
*(d++) = SSL3_MT_CERTIFICATE_REQUEST;
l2n3(n, d);
s2n(s->d1->handshake_write_seq, d);
s->d1->handshake_write_seq++;
/*
* we should now have things packed up, so lets send it off
*/
s->init_num = n + DTLS1_HM_HEADER_LENGTH;
s->init_off = 0;
#ifdef NETSCAPE_HANG_BUG
/* XXX: what to do about this? */
p = (unsigned char *)s->init_buf->data + s->init_num;
/* do the header */
*(p++) = SSL3_MT_SERVER_DONE;
*(p++) = 0;
*(p++) = 0;
*(p++) = 0;
s->init_num += 4;
#endif
/* XDTLS: set message header ? */
msg_len = s->init_num - DTLS1_HM_HEADER_LENGTH;
dtls1_set_message_header(s, (void *)s->init_buf->data,
SSL3_MT_CERTIFICATE_REQUEST, msg_len, 0,
msg_len);
/* buffer the message to handle re-xmits */
dtls1_buffer_message(s, 0);
s->state = SSL3_ST_SW_CERT_REQ_B;
}
/* SSL3_ST_SW_CERT_REQ_B */
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
err:
return (-1);
}
int dtls1_send_server_certificate(SSL *s)
{
unsigned long l;
X509 *x;
if (s->state == SSL3_ST_SW_CERT_A) {
x = ssl_get_server_send_cert(s);
if (x == NULL) {
/* VRS: allow null cert if auth == KRB5 */
if ((s->s3->tmp.new_cipher->algorithm_mkey != SSL_kKRB5) ||
(s->s3->tmp.new_cipher->algorithm_auth != SSL_aKRB5)) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_CERTIFICATE,
ERR_R_INTERNAL_ERROR);
return (0);
}
}
l = dtls1_output_cert_chain(s, x);
if (!l) {
SSLerr(SSL_F_DTLS1_SEND_SERVER_CERTIFICATE, ERR_R_INTERNAL_ERROR);
return (0);
}
s->state = SSL3_ST_SW_CERT_B;
s->init_num = (int)l;
s->init_off = 0;
/* buffer the message to handle re-xmits */
dtls1_buffer_message(s, 0);
}
/* SSL3_ST_SW_CERT_B */
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
}
#ifndef OPENSSL_NO_TLSEXT
int dtls1_send_newsession_ticket(SSL *s)
{
if (s->state == SSL3_ST_SW_SESSION_TICKET_A) {
unsigned char *p, *senc, *macstart;
int len, slen;
unsigned int hlen, msg_len;
EVP_CIPHER_CTX ctx;
HMAC_CTX hctx;
SSL_CTX *tctx = s->initial_ctx;
unsigned char iv[EVP_MAX_IV_LENGTH];
unsigned char key_name[16];
/* get session encoding length */
slen = i2d_SSL_SESSION(s->session, NULL);
/*
* Some length values are 16 bits, so forget it if session is too
* long
*/
if (slen > 0xFF00)
return -1;
/*
* Grow buffer if need be: the length calculation is as follows 12
* (DTLS handshake message header) + 4 (ticket lifetime hint) + 2
* (ticket length) + 16 (key name) + max_iv_len (iv length) +
* session_length + max_enc_block_size (max encrypted session length)
* + max_md_size (HMAC).
*/
if (!BUF_MEM_grow(s->init_buf,
DTLS1_HM_HEADER_LENGTH + 22 + EVP_MAX_IV_LENGTH +
EVP_MAX_BLOCK_LENGTH + EVP_MAX_MD_SIZE + slen))
return -1;
senc = OPENSSL_malloc(slen);
if (!senc)
return -1;
p = senc;
i2d_SSL_SESSION(s->session, &p);
p = (unsigned char *)&(s->init_buf->data[DTLS1_HM_HEADER_LENGTH]);
EVP_CIPHER_CTX_init(&ctx);
HMAC_CTX_init(&hctx);
/*
* Initialize HMAC and cipher contexts. If callback present it does
* all the work otherwise use generated values from parent ctx.
*/
if (tctx->tlsext_ticket_key_cb) {
if (tctx->tlsext_ticket_key_cb(s, key_name, iv, &ctx,
&hctx, 1) < 0) {
OPENSSL_free(senc);
return -1;
}
} else {
if (RAND_bytes(iv, 16) <= 0) {
OPENSSL_free(senc);
return -1;
}
EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
tctx->tlsext_tick_aes_key, iv);
HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
tlsext_tick_md(), NULL);
memcpy(key_name, tctx->tlsext_tick_key_name, 16);
}
l2n(s->session->tlsext_tick_lifetime_hint, p);
/* Skip ticket length for now */
p += 2;
/* Output key name */
macstart = p;
memcpy(p, key_name, 16);
p += 16;
/* output IV */
memcpy(p, iv, EVP_CIPHER_CTX_iv_length(&ctx));
p += EVP_CIPHER_CTX_iv_length(&ctx);
/* Encrypt session data */
EVP_EncryptUpdate(&ctx, p, &len, senc, slen);
p += len;
EVP_EncryptFinal(&ctx, p, &len);
p += len;
EVP_CIPHER_CTX_cleanup(&ctx);
HMAC_Update(&hctx, macstart, p - macstart);
HMAC_Final(&hctx, p, &hlen);
HMAC_CTX_cleanup(&hctx);
p += hlen;
/* Now write out lengths: p points to end of data written */
/* Total length */
len = p - (unsigned char *)(s->init_buf->data);
/* Ticket length */
p = (unsigned char *)&(s->init_buf->data[DTLS1_HM_HEADER_LENGTH]) + 4;
s2n(len - DTLS1_HM_HEADER_LENGTH - 6, p);
/* number of bytes to write */
s->init_num = len;
s->state = SSL3_ST_SW_SESSION_TICKET_B;
s->init_off = 0;
OPENSSL_free(senc);
/* XDTLS: set message header ? */
msg_len = s->init_num - DTLS1_HM_HEADER_LENGTH;
dtls1_set_message_header(s, (void *)s->init_buf->data,
SSL3_MT_NEWSESSION_TICKET, msg_len, 0,
msg_len);
/* buffer the message to handle re-xmits */
dtls1_buffer_message(s, 0);
}
/* SSL3_ST_SW_SESSION_TICKET_B */
return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
}
#endif
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