boringssl/ssl/d1_srvr.c
David Benjamin e9a3642126 Don't reset ssl->shutdown in the state machine.
This is particularly questionable with ClientHello encompassing several states.
ssl->shutdown is already initialized to zero and further reset in
SSL_set_{connect,accept}_state. At any other state, if it manages to not be a
no-op, it will erase a close_notify we have sent or received, neither of which
is okay. (I don't think this is possible, but I'm not positive.)

This dates to the initial commit in OpenSSL, so git is not enlightening. The
state machine logic historically reset many fields it had no reason to reset,
so this is likely more of that.

Change-Id: Ie872316701720cb8ef2cfcb67b7f07a9fea3620f
Reviewed-on: https://boringssl-review.googlesource.com/7874
Reviewed-by: Adam Langley <agl@google.com>
2016-05-06 17:40:17 +00:00

469 lines
15 KiB
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 <openssl/ssl.h>
#include <assert.h>
#include <openssl/bn.h>
#include <openssl/buf.h>
#include <openssl/dh.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/md5.h>
#include <openssl/rand.h>
#include <openssl/x509.h>
#include "internal.h"
int dtls1_accept(SSL *ssl) {
BUF_MEM *buf = NULL;
void (*cb)(const SSL *ssl, int type, int value) = NULL;
uint32_t alg_a;
int ret = -1;
int new_state, state, skip = 0;
assert(ssl->handshake_func == dtls1_accept);
assert(ssl->server);
assert(SSL_IS_DTLS(ssl));
ERR_clear_system_error();
if (ssl->info_callback != NULL) {
cb = ssl->info_callback;
} else if (ssl->ctx->info_callback != NULL) {
cb = ssl->ctx->info_callback;
}
for (;;) {
state = ssl->state;
switch (ssl->state) {
case SSL_ST_ACCEPT:
if (cb != NULL) {
cb(ssl, SSL_CB_HANDSHAKE_START, 1);
}
if (ssl->init_buf == NULL) {
buf = BUF_MEM_new();
if (buf == NULL || !BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
ret = -1;
goto end;
}
ssl->init_buf = buf;
buf = NULL;
}
ssl->init_num = 0;
if (!ssl_init_wbio_buffer(ssl)) {
ret = -1;
goto end;
}
if (!ssl3_init_handshake_buffer(ssl)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
ret = -1;
goto end;
}
ssl->state = SSL3_ST_SR_CLNT_HELLO_A;
break;
case SSL3_ST_SR_CLNT_HELLO_A:
case SSL3_ST_SR_CLNT_HELLO_B:
case SSL3_ST_SR_CLNT_HELLO_C:
case SSL3_ST_SR_CLNT_HELLO_D:
ret = ssl3_get_client_hello(ssl);
if (ret <= 0) {
goto end;
}
dtls1_stop_timer(ssl);
ssl->state = SSL3_ST_SW_SRVR_HELLO_A;
ssl->init_num = 0;
break;
case SSL3_ST_SW_SRVR_HELLO_A:
case SSL3_ST_SW_SRVR_HELLO_B:
dtls1_start_timer(ssl);
ret = ssl3_send_server_hello(ssl);
if (ret <= 0) {
goto end;
}
if (ssl->hit) {
if (ssl->tlsext_ticket_expected) {
ssl->state = SSL3_ST_SW_SESSION_TICKET_A;
} else {
ssl->state = SSL3_ST_SW_CHANGE_A;
}
} else {
ssl->state = SSL3_ST_SW_CERT_A;
}
ssl->init_num = 0;
break;
case SSL3_ST_SW_CERT_A:
case SSL3_ST_SW_CERT_B:
if (ssl_cipher_has_server_public_key(ssl->s3->tmp.new_cipher)) {
dtls1_start_timer(ssl);
ret = ssl3_send_server_certificate(ssl);
if (ret <= 0) {
goto end;
}
if (ssl->s3->tmp.certificate_status_expected) {
ssl->state = SSL3_ST_SW_CERT_STATUS_A;
} else {
ssl->state = SSL3_ST_SW_KEY_EXCH_A;
}
} else {
skip = 1;
ssl->state = SSL3_ST_SW_KEY_EXCH_A;
}
ssl->init_num = 0;
break;
case SSL3_ST_SW_CERT_STATUS_A:
case SSL3_ST_SW_CERT_STATUS_B:
ret = ssl3_send_certificate_status(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SW_KEY_EXCH_A;
ssl->init_num = 0;
break;
case SSL3_ST_SW_KEY_EXCH_A:
case SSL3_ST_SW_KEY_EXCH_B:
case SSL3_ST_SW_KEY_EXCH_C:
alg_a = ssl->s3->tmp.new_cipher->algorithm_auth;
/* Send a ServerKeyExchange message if:
* - The key exchange is ephemeral or anonymous
* Diffie-Hellman.
* - There is a PSK identity hint.
*
* TODO(davidben): This logic is currently duplicated
* in s3_srvr.c. Fix this. In the meantime, keep them
* in sync. */
if (ssl_cipher_requires_server_key_exchange(ssl->s3->tmp.new_cipher) ||
((alg_a & SSL_aPSK) && ssl->psk_identity_hint)) {
dtls1_start_timer(ssl);
ret = ssl3_send_server_key_exchange(ssl);
if (ret <= 0) {
goto end;
}
} else {
skip = 1;
}
ssl->state = SSL3_ST_SW_CERT_REQ_A;
ssl->init_num = 0;
break;
case SSL3_ST_SW_CERT_REQ_A:
case SSL3_ST_SW_CERT_REQ_B:
if (ssl->s3->tmp.cert_request) {
dtls1_start_timer(ssl);
ret = ssl3_send_certificate_request(ssl);
if (ret <= 0) {
goto end;
}
} else {
skip = 1;
}
ssl->state = SSL3_ST_SW_SRVR_DONE_A;
ssl->init_num = 0;
break;
case SSL3_ST_SW_SRVR_DONE_A:
case SSL3_ST_SW_SRVR_DONE_B:
dtls1_start_timer(ssl);
ret = ssl3_send_server_done(ssl);
if (ret <= 0) {
goto end;
}
ssl->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
ssl->state = SSL3_ST_SW_FLUSH;
ssl->init_num = 0;
break;
case SSL3_ST_SW_FLUSH:
if (BIO_flush(ssl->wbio) <= 0) {
ssl->rwstate = SSL_WRITING;
ret = -1;
goto end;
}
ssl->state = ssl->s3->tmp.next_state;
break;
case SSL3_ST_SR_CERT_A:
case SSL3_ST_SR_CERT_B:
if (ssl->s3->tmp.cert_request) {
ret = ssl3_get_client_certificate(ssl);
if (ret <= 0) {
goto end;
}
}
ssl->init_num = 0;
ssl->state = SSL3_ST_SR_KEY_EXCH_A;
break;
case SSL3_ST_SR_KEY_EXCH_A:
case SSL3_ST_SR_KEY_EXCH_B:
case SSL3_ST_SR_KEY_EXCH_C:
ret = ssl3_get_client_key_exchange(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SR_CERT_VRFY_A;
ssl->init_num = 0;
break;
case SSL3_ST_SR_CERT_VRFY_A:
case SSL3_ST_SR_CERT_VRFY_B:
ret = ssl3_get_cert_verify(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SR_CHANGE;
ssl->init_num = 0;
break;
case SSL3_ST_SR_CHANGE:
ret = ssl->method->ssl_read_change_cipher_spec(ssl);
if (ret <= 0) {
goto end;
}
if (!tls1_change_cipher_state(ssl, SSL3_CHANGE_CIPHER_SERVER_READ)) {
ret = -1;
goto end;
}
ssl->state = SSL3_ST_SR_FINISHED_A;
break;
case SSL3_ST_SR_FINISHED_A:
case SSL3_ST_SR_FINISHED_B:
ret = ssl3_get_finished(ssl, SSL3_ST_SR_FINISHED_A,
SSL3_ST_SR_FINISHED_B);
if (ret <= 0) {
goto end;
}
dtls1_stop_timer(ssl);
if (ssl->hit) {
ssl->state = SSL_ST_OK;
} else if (ssl->tlsext_ticket_expected) {
ssl->state = SSL3_ST_SW_SESSION_TICKET_A;
} else {
ssl->state = SSL3_ST_SW_CHANGE_A;
}
ssl->init_num = 0;
break;
case SSL3_ST_SW_SESSION_TICKET_A:
case SSL3_ST_SW_SESSION_TICKET_B:
ret = ssl3_send_new_session_ticket(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SW_CHANGE_A;
ssl->init_num = 0;
break;
case SSL3_ST_SW_CHANGE_A:
case SSL3_ST_SW_CHANGE_B:
ret = dtls1_send_change_cipher_spec(ssl, SSL3_ST_SW_CHANGE_A,
SSL3_ST_SW_CHANGE_B);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SW_FINISHED_A;
ssl->init_num = 0;
if (!tls1_change_cipher_state(ssl, SSL3_CHANGE_CIPHER_SERVER_WRITE)) {
ret = -1;
goto end;
}
break;
case SSL3_ST_SW_FINISHED_A:
case SSL3_ST_SW_FINISHED_B:
ret = ssl3_send_finished(ssl, SSL3_ST_SW_FINISHED_A,
SSL3_ST_SW_FINISHED_B);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SW_FLUSH;
if (ssl->hit) {
ssl->s3->tmp.next_state = SSL3_ST_SR_CHANGE;
} else {
ssl->s3->tmp.next_state = SSL_ST_OK;
}
ssl->init_num = 0;
break;
case SSL_ST_OK:
ssl3_cleanup_key_block(ssl);
/* remove buffering on output */
ssl_free_wbio_buffer(ssl);
ssl->init_num = 0;
ssl->s3->initial_handshake_complete = 1;
ssl_update_cache(ssl, SSL_SESS_CACHE_SERVER);
if (cb != NULL) {
cb(ssl, SSL_CB_HANDSHAKE_DONE, 1);
}
ret = 1;
/* done handshaking, next message is client hello */
ssl->d1->handshake_read_seq = 0;
/* next message is server hello */
ssl->d1->handshake_write_seq = 0;
ssl->d1->next_handshake_write_seq = 0;
goto end;
default:
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_STATE);
ret = -1;
goto end;
}
if (!ssl->s3->tmp.reuse_message && !skip) {
if (cb != NULL && ssl->state != state) {
new_state = ssl->state;
ssl->state = state;
cb(ssl, SSL_CB_ACCEPT_LOOP, 1);
ssl->state = new_state;
}
}
skip = 0;
}
end:
BUF_MEM_free(buf);
if (cb != NULL) {
cb(ssl, SSL_CB_ACCEPT_EXIT, ret);
}
return ret;
}