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boringssl/ssl/s3_pkt.c
David Benjamin 1d5ef3bb1e Add SSL_set_renegotiate_mode. 
Add a slightly richer API. Notably, one can configure ssl_renegotiate_once to
only accept the first renego.

Also, this API doesn't repeat the mistake I made with
SSL_set_reject_peer_renegotiations which is super-confusing with the negation.

Change-Id: I7eb5d534e3e6c553b641793f4677fe5a56451c71
Reviewed-on: https://boringssl-review.googlesource.com/6221
Reviewed-by: Adam Langley <agl@google.com>
2015-10-13 18:02:28 +00:00

821 lines
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/* 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.]
*/
/* ====================================================================
* Copyright (c) 1998-2002 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). */
#include <openssl/ssl.h>
#include <assert.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <openssl/buf.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/mem.h>
#include <openssl/rand.h>
#include "internal.h"
static int do_ssl3_write(SSL *s, int type, const uint8_t *buf, unsigned len);
/* kMaxWarningAlerts is the number of consecutive warning alerts that will be
* processed. */
static const uint8_t kMaxWarningAlerts = 4;
/* ssl3_get_record reads a new input record. On success, it places it in
* |ssl->s3->rrec| and returns one. Otherwise it returns <= 0 on error or if
* more data is needed. */
static int ssl3_get_record(SSL *ssl) {
int ret;
again:
/* Ensure the buffer is large enough to decrypt in-place. */
ret = ssl_read_buffer_extend_to(ssl, ssl_record_prefix_len(ssl));
if (ret <= 0) {
return ret;
}
assert(ssl_read_buffer_len(ssl) >= ssl_record_prefix_len(ssl));
uint8_t *out = ssl_read_buffer(ssl) + ssl_record_prefix_len(ssl);
size_t max_out = ssl_read_buffer_len(ssl) - ssl_record_prefix_len(ssl);
uint8_t type, alert;
size_t len, consumed;
switch (tls_open_record(ssl, &type, out, &len, &consumed, &alert, max_out,
ssl_read_buffer(ssl), ssl_read_buffer_len(ssl))) {
case ssl_open_record_success:
ssl_read_buffer_consume(ssl, consumed);
if (len > 0xffff) {
OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
return -1;
}
SSL3_RECORD *rr = &ssl->s3->rrec;
rr->type = type;
rr->length = (uint16_t)len;
rr->off = 0;
rr->data = out;
return 1;
case ssl_open_record_partial:
ret = ssl_read_buffer_extend_to(ssl, consumed);
if (ret <= 0) {
return ret;
}
goto again;
case ssl_open_record_discard:
ssl_read_buffer_consume(ssl, consumed);
goto again;
case ssl_open_record_error:
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return -1;
}
assert(0);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
int ssl3_write_app_data(SSL *ssl, const void *buf, int len) {
return ssl3_write_bytes(ssl, SSL3_RT_APPLICATION_DATA, buf, len);
}
/* Call this to write data in records of type |type|. It will return <= 0 if
* not all data has been sent or non-blocking IO. */
int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) {
const uint8_t *buf = buf_;
unsigned int tot, n, nw;
int i;
s->rwstate = SSL_NOTHING;
assert(s->s3->wnum <= INT_MAX);
tot = s->s3->wnum;
s->s3->wnum = 0;
if (!s->in_handshake && SSL_in_init(s) && !SSL_in_false_start(s)) {
i = s->handshake_func(s);
if (i < 0) {
return i;
}
if (i == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
return -1;
}
}
/* Ensure that if we end up with a smaller value of data to write out than
* the the original len from a write which didn't complete for non-blocking
* I/O and also somehow ended up avoiding the check for this in
* ssl3_write_pending/SSL_R_BAD_WRITE_RETRY as it must never be possible to
* end up with (len-tot) as a large number that will then promptly send
* beyond the end of the users buffer ... so we trap and report the error in
* a way the user will notice. */
if (len < 0 || (size_t)len < tot) {
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_LENGTH);
return -1;
}
n = (len - tot);
for (;;) {
/* max contains the maximum number of bytes that we can put into a
* record. */
unsigned max = s->max_send_fragment;
if (n > max) {
nw = max;
} else {
nw = n;
}
i = do_ssl3_write(s, type, &buf[tot], nw);
if (i <= 0) {
s->s3->wnum = tot;
return i;
}
if (i == (int)n || (type == SSL3_RT_APPLICATION_DATA &&
(s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) {
return tot + i;
}
n -= i;
tot += i;
}
}
/* do_ssl3_write writes an SSL record of the given type. */
static int do_ssl3_write(SSL *s, int type, const uint8_t *buf, unsigned len) {
/* If there is still data from the previous record, flush it. */
if (ssl_write_buffer_is_pending(s)) {
return ssl3_write_pending(s, type, buf, len);
}
/* If we have an alert to send, lets send it */
if (s->s3->alert_dispatch) {
int ret = s->method->ssl_dispatch_alert(s);
if (ret <= 0) {
return ret;
}
/* if it went, fall through and send more stuff */
}
if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
if (len == 0) {
return 0;
}
size_t max_out = len + ssl_max_seal_overhead(s);
if (max_out < len) {
OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
return -1;
}
uint8_t *out;
size_t ciphertext_len;
if (!ssl_write_buffer_init(s, &out, max_out) ||
!tls_seal_record(s, out, &ciphertext_len, max_out, type, buf, len)) {
return -1;
}
ssl_write_buffer_set_len(s, ciphertext_len);
/* memorize arguments so that ssl3_write_pending can detect bad write retries
* later */
s->s3->wpend_tot = len;
s->s3->wpend_buf = buf;
s->s3->wpend_type = type;
s->s3->wpend_ret = len;
/* we now just need to write the buffer */
return ssl3_write_pending(s, type, buf, len);
}
int ssl3_write_pending(SSL *s, int type, const uint8_t *buf, unsigned int len) {
if (s->s3->wpend_tot > (int)len ||
(s->s3->wpend_buf != buf &&
!(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) ||
s->s3->wpend_type != type) {
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_WRITE_RETRY);
return -1;
}
int ret = ssl_write_buffer_flush(s);
if (ret <= 0) {
return ret;
}
return s->s3->wpend_ret;
}
/* ssl3_expect_change_cipher_spec informs the record layer that a
* ChangeCipherSpec record is required at this point. If a Handshake record is
* received before ChangeCipherSpec, the connection will fail. Moreover, if
* there are unprocessed handshake bytes, the handshake will also fail and the
* function returns zero. Otherwise, the function returns one. */
int ssl3_expect_change_cipher_spec(SSL *s) {
if (s->s3->handshake_fragment_len > 0 || s->s3->tmp.reuse_message) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNPROCESSED_HANDSHAKE_DATA);
return 0;
}
s->s3->flags |= SSL3_FLAGS_EXPECT_CCS;
return 1;
}
int ssl3_read_app_data(SSL *ssl, uint8_t *buf, int len, int peek) {
return ssl3_read_bytes(ssl, SSL3_RT_APPLICATION_DATA, buf, len, peek);
}
void ssl3_read_close_notify(SSL *ssl) {
ssl3_read_bytes(ssl, 0, NULL, 0, 0);
}
static int ssl3_can_renegotiate(SSL *ssl) {
switch (ssl->renegotiate_mode) {
case ssl_renegotiate_never:
return 0;
case ssl_renegotiate_once:
return ssl->s3->total_renegotiations == 0;
case ssl_renegotiate_freely:
return 1;
}
assert(0);
return 0;
}
/* Return up to 'len' payload bytes received in 'type' records.
* 'type' is one of the following:
*
* - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
* - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
* - 0 (during a shutdown, no data has to be returned)
*
* If we don't have stored data to work from, read a SSL/TLS record first
* (possibly multiple records if we still don't have anything to return).
*
* This function must handle any surprises the peer may have for us, such as
* Alert records (e.g. close_notify), ChangeCipherSpec records (not really
* a surprise, but handled as if it were), or renegotiation requests.
* Also if record payloads contain fragments too small to process, we store
* them until there is enough for the respective protocol (the record protocol
* may use arbitrary fragmentation and even interleaving):
* Change cipher spec protocol
* just 1 byte needed, no need for keeping anything stored
* Alert protocol
* 2 bytes needed (AlertLevel, AlertDescription)
* Handshake protocol
* 4 bytes needed (HandshakeType, uint24 length) -- we just have
* to detect unexpected Client Hello and Hello Request messages
* here, anything else is handled by higher layers
* Application data protocol
* none of our business
*/
int ssl3_read_bytes(SSL *s, int type, uint8_t *buf, int len, int peek) {
int al, i, ret;
unsigned int n;
SSL3_RECORD *rr;
void (*cb)(const SSL *ssl, int type2, int val) = NULL;
if ((type && type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) ||
(peek && type != SSL3_RT_APPLICATION_DATA)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
if (type == SSL3_RT_HANDSHAKE && s->s3->handshake_fragment_len > 0) {
/* (partially) satisfy request from storage */
uint8_t *src = s->s3->handshake_fragment;
uint8_t *dst = buf;
unsigned int k;
/* peek == 0 */
n = 0;
while (len > 0 && s->s3->handshake_fragment_len > 0) {
*dst++ = *src++;
len--;
s->s3->handshake_fragment_len--;
n++;
}
/* move any remaining fragment bytes: */
for (k = 0; k < s->s3->handshake_fragment_len; k++) {
s->s3->handshake_fragment[k] = *src++;
}
return n;
}
/* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
/* This may require multiple iterations. False Start will cause
* |s->handshake_func| to signal success one step early, but the handshake
* must be completely finished before other modes are accepted.
*
* TODO(davidben): Move this check up to a higher level. */
while (!s->in_handshake && SSL_in_init(s)) {
assert(type == SSL3_RT_APPLICATION_DATA);
i = s->handshake_func(s);
if (i < 0) {
return i;
}
if (i == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
return -1;
}
}
start:
s->rwstate = SSL_NOTHING;
/* s->s3->rrec.type - is the type of record
* s->s3->rrec.data - data
* s->s3->rrec.off - offset into 'data' for next read
* s->s3->rrec.length - number of bytes. */
rr = &s->s3->rrec;
/* get new packet if necessary */
if (rr->length == 0) {
ret = ssl3_get_record(s);
if (ret <= 0) {
return ret;
}
}
/* we now have a packet which can be read and processed */
/* |change_cipher_spec is set when we receive a ChangeCipherSpec and reset by
* ssl3_get_finished. */
if (s->s3->change_cipher_spec && rr->type != SSL3_RT_HANDSHAKE &&
rr->type != SSL3_RT_ALERT) {
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
goto f_err;
}
/* If we are expecting a ChangeCipherSpec, it is illegal to receive a
* Handshake record. */
if (rr->type == SSL3_RT_HANDSHAKE && (s->s3->flags & SSL3_FLAGS_EXPECT_CCS)) {
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_HANDSHAKE_RECORD_BEFORE_CCS);
goto f_err;
}
/* If the other end has shut down, throw anything we read away (even in
* 'peek' mode) */
if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
rr->length = 0;
s->rwstate = SSL_NOTHING;
return 0;
}
if (type != 0 && type == rr->type) {
s->s3->warning_alert_count = 0;
/* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
/* make sure that we are not getting application data when we are doing a
* handshake for the first time */
if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA &&
s->aead_read_ctx == NULL) {
/* TODO(davidben): Is this check redundant with the handshake_func
* check? */
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_APP_DATA_IN_HANDSHAKE);
goto f_err;
}
/* Discard empty records. */
if (rr->length == 0) {
goto start;
}
if (len <= 0) {
return len;
}
if ((unsigned int)len > rr->length) {
n = rr->length;
} else {
n = (unsigned int)len;
}
memcpy(buf, &(rr->data[rr->off]), n);
if (!peek) {
rr->length -= n;
rr->off += n;
if (rr->length == 0) {
rr->off = 0;
/* The record has been consumed, so we may now clear the buffer. */
ssl_read_buffer_discard(s);
}
}
return n;
}
/* Process unexpected records. */
if (rr->type == SSL3_RT_HANDSHAKE) {
/* If peer renegotiations are disabled, all out-of-order handshake records
* are fatal. Renegotiations as a server are never supported. */
if (s->server || !ssl3_can_renegotiate(s)) {
al = SSL_AD_NO_RENEGOTIATION;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_RENEGOTIATION);
goto f_err;
}
/* HelloRequests may be fragmented across multiple records. */
const size_t size = sizeof(s->s3->handshake_fragment);
const size_t avail = size - s->s3->handshake_fragment_len;
const size_t todo = (rr->length < avail) ? rr->length : avail;
memcpy(s->s3->handshake_fragment + s->s3->handshake_fragment_len,
&rr->data[rr->off], todo);
rr->off += todo;
rr->length -= todo;
s->s3->handshake_fragment_len += todo;
if (s->s3->handshake_fragment_len < size) {
goto start; /* fragment was too small */
}
/* Parse out and consume a HelloRequest. */
if (s->s3->handshake_fragment[0] != SSL3_MT_HELLO_REQUEST ||
s->s3->handshake_fragment[1] != 0 ||
s->s3->handshake_fragment[2] != 0 ||
s->s3->handshake_fragment[3] != 0) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HELLO_REQUEST);
goto f_err;
}
s->s3->handshake_fragment_len = 0;
if (s->msg_callback) {
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
}
if (!SSL_is_init_finished(s) || !s->s3->initial_handshake_complete) {
/* This cannot happen. If a handshake is in progress, |type| must be
* |SSL3_RT_HANDSHAKE|. */
assert(0);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
goto err;
}
/* Renegotiation is only supported at quiescent points in the application
* protocol, namely in HTTPS, just before reading the HTTP response. Require
* the record-layer be idle and avoid complexities of sending a handshake
* record while an application_data record is being written. */
if (ssl_write_buffer_is_pending(s)) {
al = SSL_AD_NO_RENEGOTIATION;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_RENEGOTIATION);
goto f_err;
}
/* Begin a new handshake. */
s->s3->total_renegotiations++;
s->state = SSL_ST_CONNECT;
i = s->handshake_func(s);
if (i < 0) {
return i;
}
if (i == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
return -1;
}
/* The handshake completed synchronously. Continue reading records. */
goto start;
}
/* If an alert record, process one alert out of the record. Note that we allow
* a single record to contain multiple alerts. */
if (rr->type == SSL3_RT_ALERT) {
/* Alerts may not be fragmented. */
if (rr->length < 2) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT);
goto f_err;
}
if (s->msg_callback) {
s->msg_callback(0, s->version, SSL3_RT_ALERT, &rr->data[rr->off], 2, s,
s->msg_callback_arg);
}
const uint8_t alert_level = rr->data[rr->off++];
const uint8_t alert_descr = rr->data[rr->off++];
rr->length -= 2;
if (s->info_callback != NULL) {
cb = s->info_callback;
} else if (s->ctx->info_callback != NULL) {
cb = s->ctx->info_callback;
}
if (cb != NULL) {
uint16_t alert = (alert_level << 8) | alert_descr;
cb(s, SSL_CB_READ_ALERT, alert);
}
if (alert_level == SSL3_AL_WARNING) {
s->s3->warn_alert = alert_descr;
if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
s->shutdown |= SSL_RECEIVED_SHUTDOWN;
return 0;
}
/* This is a warning but we receive it if we requested renegotiation and
* the peer denied it. Terminate with a fatal alert because if
* application tried to renegotiatie it presumably had a good reason and
* expects it to succeed.
*
* In future we might have a renegotiation where we don't care if the
* peer refused it where we carry on. */
else if (alert_descr == SSL_AD_NO_RENEGOTIATION) {
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_RENEGOTIATION);
goto f_err;
}
s->s3->warning_alert_count++;
if (s->s3->warning_alert_count > kMaxWarningAlerts) {
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MANY_WARNING_ALERTS);
goto f_err;
}
} else if (alert_level == SSL3_AL_FATAL) {
char tmp[16];
s->rwstate = SSL_NOTHING;
s->s3->fatal_alert = alert_descr;
OPENSSL_PUT_ERROR(SSL, SSL_AD_REASON_OFFSET + alert_descr);
BIO_snprintf(tmp, sizeof(tmp), "%d", alert_descr);
ERR_add_error_data(2, "SSL alert number ", tmp);
s->shutdown |= SSL_RECEIVED_SHUTDOWN;
SSL_CTX_remove_session(s->ctx, s->session);
return 0;
} else {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_ALERT_TYPE);
goto f_err;
}
goto start;
}
if (s->shutdown & SSL_SENT_SHUTDOWN) {
/* close_notify has been sent, so discard all records other than alerts. */
rr->length = 0;
goto start;
}
if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
/* 'Change Cipher Spec' is just a single byte, so we know exactly what the
* record payload has to look like */
if (rr->length != 1 || rr->off != 0 || rr->data[0] != SSL3_MT_CCS) {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_CHANGE_CIPHER_SPEC);
goto f_err;
}
/* Check we have a cipher to change to */
if (s->s3->tmp.new_cipher == NULL) {
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_CCS_RECEIVED_EARLY);
goto f_err;
}
if (!(s->s3->flags & SSL3_FLAGS_EXPECT_CCS)) {
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_CCS_RECEIVED_EARLY);
goto f_err;
}
s->s3->flags &= ~SSL3_FLAGS_EXPECT_CCS;
rr->length = 0;
if (s->msg_callback) {
s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s,
s->msg_callback_arg);
}
s->s3->change_cipher_spec = 1;
if (!ssl3_do_change_cipher_spec(s)) {
goto err;
} else {
goto start;
}
}
/* We already handled these. */
assert(rr->type != SSL3_RT_CHANGE_CIPHER_SPEC && rr->type != SSL3_RT_ALERT &&
rr->type != SSL3_RT_HANDSHAKE);
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
err:
return -1;
}
int ssl3_do_change_cipher_spec(SSL *s) {
int i;
if (s->state & SSL_ST_ACCEPT) {
i = SSL3_CHANGE_CIPHER_SERVER_READ;
} else {
i = SSL3_CHANGE_CIPHER_CLIENT_READ;
}
if (s->s3->tmp.key_block == NULL) {
if (s->session == NULL || s->session->master_key_length == 0) {
/* might happen if dtls1_read_bytes() calls this */
OPENSSL_PUT_ERROR(SSL, SSL_R_CCS_RECEIVED_EARLY);
return 0;
}
s->session->cipher = s->s3->tmp.new_cipher;
if (!s->enc_method->setup_key_block(s)) {
return 0;
}
}
if (!s->enc_method->change_cipher_state(s, i)) {
return 0;
}
return 1;
}
int ssl3_send_alert(SSL *s, int level, int desc) {
/* Map tls/ssl alert value to correct one */
desc = s->enc_method->alert_value(desc);
if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION) {
/* SSL 3.0 does not have protocol_version alerts */
desc = SSL_AD_HANDSHAKE_FAILURE;
}
if (desc < 0) {
return -1;
}
/* If a fatal one, remove from cache */
if (level == 2 && s->session != NULL) {
SSL_CTX_remove_session(s->ctx, s->session);
}
s->s3->alert_dispatch = 1;
s->s3->send_alert[0] = level;
s->s3->send_alert[1] = desc;
if (!ssl_write_buffer_is_pending(s)) {
/* Nothing is being written out, so the alert may be dispatched
* immediately. */
return s->method->ssl_dispatch_alert(s);
}
/* else data is still being written out, we will get written some time in the
* future */
return -1;
}
int ssl3_dispatch_alert(SSL *s) {
int i, j;
void (*cb)(const SSL *ssl, int type, int val) = NULL;
s->s3->alert_dispatch = 0;
i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2);
if (i <= 0) {
s->s3->alert_dispatch = 1;
} else {
/* Alert sent to BIO. If it is important, flush it now. If the message
* does not get sent due to non-blocking IO, we will not worry too much. */
if (s->s3->send_alert[0] == SSL3_AL_FATAL) {
BIO_flush(s->wbio);
}
if (s->msg_callback) {
s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s,
s->msg_callback_arg);
}
if (s->info_callback != NULL) {
cb = s->info_callback;
} else if (s->ctx->info_callback != NULL) {
cb = s->ctx->info_callback;
}
if (cb != NULL) {
j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1];
cb(s, SSL_CB_WRITE_ALERT, j);
}
}
return i;
}
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