boringssl/ssl/d1_pkt.c
David Benjamin 9a41d1b946 Deprecate SSL_*_read_ahead and enforce DTLS packet boundaries.
Now that WebRTC honors packet boundaries (https://crbug.com/447431), we
can start enforcing them correctly. Configuring read-ahead now does
nothing. Instead DTLS will always set "read-ahead" and also correctly
enforce packet boundaries when reading records. Add tests to ensure that
badly fragmented packets are ignored. Because such packets don't fail
the handshake, the tests work by injecting an alert in the front of the
handshake stream and ensuring the DTLS implementation ignores them.

ssl3_read_n can be be considerably unraveled now, but leave that for
future cleanup. For now, make it correct.

BUG=468889

Change-Id: I800cfabe06615af31c2ccece436ca52aed9fe899
Reviewed-on: https://boringssl-review.googlesource.com/4820
Reviewed-by: Adam Langley <agl@google.com>
2015-05-21 18:29:34 +00:00

921 lines
29 KiB
C

/* DTLS implementation written by Nagendra Modadugu
* (nagendra@cs.stanford.edu) for the OpenSSL project 2005. */
/* ====================================================================
* Copyright (c) 1998-2005 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 <assert.h>
#include <stdio.h>
#include <string.h>
#include <openssl/buf.h>
#include <openssl/mem.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include "internal.h"
/* mod 128 saturating subtract of two 64-bit values in big-endian order */
static int satsub64be(const uint8_t *v1, const uint8_t *v2) {
int ret, sat, brw, i;
if (sizeof(long) == 8) {
do {
const union {
long one;
char little;
} is_endian = {1};
long l;
if (is_endian.little) {
break;
}
/* not reached on little-endians */
/* following test is redundant, because input is
* always aligned, but I take no chances... */
if (((size_t)v1 | (size_t)v2) & 0x7) {
break;
}
l = *((long *)v1);
l -= *((long *)v2);
if (l > 128) {
return 128;
} else if (l < -128) {
return -128;
} else {
return (int)l;
}
} while (0);
}
ret = (int)v1[7] - (int)v2[7];
sat = 0;
brw = ret >> 8; /* brw is either 0 or -1 */
if (ret & 0x80) {
for (i = 6; i >= 0; i--) {
brw += (int)v1[i] - (int)v2[i];
sat |= ~brw;
brw >>= 8;
}
} else {
for (i = 6; i >= 0; i--) {
brw += (int)v1[i] - (int)v2[i];
sat |= brw;
brw >>= 8;
}
}
brw <<= 8; /* brw is either 0 or -256 */
if (sat & 0xff) {
return brw | 0x80;
} else {
return brw + (ret & 0xFF);
}
}
static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
static int dtls1_process_record(SSL *s);
static int do_dtls1_write(SSL *s, int type, const uint8_t *buf,
unsigned int len, enum dtls1_use_epoch_t use_epoch);
static int dtls1_process_record(SSL *s) {
int al;
SSL3_RECORD *rr = &s->s3->rrec;
/* check is not needed I believe */
if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
al = SSL_AD_RECORD_OVERFLOW;
OPENSSL_PUT_ERROR(SSL, dtls1_process_record,
SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
goto f_err;
}
/* |rr->data| points to |rr->length| bytes of ciphertext in |s->packet|. */
rr->data = &s->packet[DTLS1_RT_HEADER_LENGTH];
uint8_t seq[8];
seq[0] = rr->epoch >> 8;
seq[1] = rr->epoch & 0xff;
memcpy(&seq[2], &rr->seq_num[2], 6);
/* Decrypt the packet in-place. Note it is important that |SSL_AEAD_CTX_open|
* not write beyond |rr->length|. There may be another record in the packet.
*
* TODO(davidben): This assumes |s->version| is the same as the record-layer
* version which isn't always true, but it only differs with the NULL cipher
* which ignores the parameter. */
size_t plaintext_len;
if (!SSL_AEAD_CTX_open(s->aead_read_ctx, rr->data, &plaintext_len, rr->length,
rr->type, s->version, seq, rr->data, rr->length)) {
/* Bad packets are silently dropped in DTLS. Clear the error queue of any
* errors decryption may have added. */
ERR_clear_error();
rr->length = 0;
s->packet_length = 0;
goto err;
}
if (plaintext_len > SSL3_RT_MAX_PLAIN_LENGTH) {
al = SSL_AD_RECORD_OVERFLOW;
OPENSSL_PUT_ERROR(SSL, dtls1_process_record, SSL_R_DATA_LENGTH_TOO_LONG);
goto f_err;
}
assert(plaintext_len < (1u << 16));
rr->length = plaintext_len;
rr->off = 0;
/* So at this point the following is true
* ssl->s3->rrec.type is the type of record
* ssl->s3->rrec.length == number of bytes in record
* ssl->s3->rrec.off == offset to first valid byte
* ssl->s3->rrec.data == the first byte of the record body. */
/* we have pulled in a full packet so zero things */
s->packet_length = 0;
return 1;
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
err:
return 0;
}
/* Call this to get a new input record.
* It will return <= 0 if more data is needed, normally due to an error
* or non-blocking IO.
* When it finishes, one packet has been decoded and can be found in
* ssl->s3->rrec.type - is the type of record
* ssl->s3->rrec.data, - data
* ssl->s3->rrec.length, - number of bytes
*
* used only by dtls1_read_bytes */
int dtls1_get_record(SSL *s) {
uint8_t ssl_major, ssl_minor;
int n;
SSL3_RECORD *rr;
uint8_t *p = NULL;
uint16_t version;
rr = &(s->s3->rrec);
/* get something from the wire */
again:
/* check if we have the header */
if ((s->rstate != SSL_ST_READ_BODY) ||
(s->packet_length < DTLS1_RT_HEADER_LENGTH)) {
n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, 0);
/* read timeout is handled by dtls1_read_bytes */
if (n <= 0) {
return n; /* error or non-blocking */
}
/* this packet contained a partial record, dump it */
if (s->packet_length != DTLS1_RT_HEADER_LENGTH) {
s->packet_length = 0;
goto again;
}
s->rstate = SSL_ST_READ_BODY;
p = s->packet;
if (s->msg_callback) {
s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s,
s->msg_callback_arg);
}
/* Pull apart the header into the DTLS1_RECORD */
rr->type = *(p++);
ssl_major = *(p++);
ssl_minor = *(p++);
version = (((uint16_t)ssl_major) << 8) | ssl_minor;
/* sequence number is 64 bits, with top 2 bytes = epoch */
n2s(p, rr->epoch);
memcpy(&(s->s3->read_sequence[2]), p, 6);
p += 6;
n2s(p, rr->length);
/* Lets check version */
if (s->s3->have_version) {
if (version != s->version) {
/* The record's version doesn't match, so silently drop it.
*
* TODO(davidben): This doesn't work. The DTLS record layer is not
* packet-based, so the remainder of the packet isn't dropped and we
* get a framing error. It's also unclear what it means to silently
* drop a record in a packet containing two records. */
rr->length = 0;
s->packet_length = 0;
goto again;
}
}
if ((version & 0xff00) != (s->version & 0xff00)) {
/* wrong version, silently discard record */
rr->length = 0;
s->packet_length = 0;
goto again;
}
if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
/* record too long, silently discard it */
rr->length = 0;
s->packet_length = 0;
goto again;
}
/* now s->rstate == SSL_ST_READ_BODY */
}
/* s->rstate == SSL_ST_READ_BODY, get and decode the data */
if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) {
/* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
n = ssl3_read_n(s, rr->length, 1);
/* This packet contained a partial record, dump it. */
if (n != rr->length) {
rr->length = 0;
s->packet_length = 0;
goto again;
}
/* now n == rr->length,
* and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
}
s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */
if (rr->epoch != s->d1->r_epoch) {
/* This record is from the wrong epoch. If it is the next epoch, it could be
* buffered. For simplicity, drop it and expect retransmit to handle it
* later; DTLS is supposed to handle packet loss. */
rr->length = 0;
s->packet_length = 0;
goto again;
}
/* Check whether this is a repeat, or aged record. */
if (!dtls1_record_replay_check(s, &s->d1->bitmap)) {
rr->length = 0;
s->packet_length = 0; /* dump this record */
goto again; /* get another record */
}
/* just read a 0 length packet */
if (rr->length == 0) {
goto again;
}
if (!dtls1_process_record(s)) {
rr->length = 0;
s->packet_length = 0; /* dump this record */
goto again; /* get another record */
}
dtls1_record_bitmap_update(s, &s->d1->bitmap); /* Mark receipt of record. */
return 1;
}
/* 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 dtls1_read_bytes(SSL *s, int type, unsigned char *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;
/* XXX: check what the second '&& type' is about */
if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
(type != SSL3_RT_HANDSHAKE) && type) ||
(peek && (type != SSL3_RT_APPLICATION_DATA))) {
OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, ERR_R_INTERNAL_ERROR);
return -1;
}
if (!s->in_handshake && SSL_in_init(s)) {
/* type == SSL3_RT_APPLICATION_DATA */
i = s->handshake_func(s);
if (i < 0) {
return i;
}
if (i == 0) {
OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, 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;
/* Check for timeout */
if (DTLSv1_handle_timeout(s) > 0) {
goto start;
}
/* get new packet if necessary */
if (rr->length == 0 || s->rstate == SSL_ST_READ_BODY) {
ret = dtls1_get_record(s);
if (ret <= 0) {
ret = dtls1_read_failed(s, ret);
/* anything other than a timeout is an error */
if (ret <= 0) {
return ret;
} else {
goto start;
}
}
}
/* 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) {
/* We now have an unexpected record between CCS and Finished. Most likely
* the packets were reordered on their way. DTLS is unreliable, so drop the
* packet and expect the peer to retransmit. */
rr->length = 0;
goto start;
}
/* 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 == rr->type) { /* 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, dtls1_read_bytes, SSL_R_APP_DATA_IN_HANDSHAKE);
goto f_err;
}
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) {
s->rstate = SSL_ST_READ_HEADER;
rr->off = 0;
}
}
return n;
}
/* If we get here, then type != rr->type. */
/* 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, dtls1_read_bytes, 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;
}
} else if (alert_level == SSL3_AL_FATAL) {
char tmp[16];
s->rwstate = SSL_NOTHING;
s->s3->fatal_alert = alert_descr;
OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes,
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, dtls1_read_bytes, SSL_R_UNKNOWN_ALERT_TYPE);
goto f_err;
}
goto start;
}
if (s->shutdown & SSL_SENT_SHUTDOWN) {
/* but we have not received a shutdown */
s->rwstate = SSL_NOTHING;
rr->length = 0;
return 0;
}
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, dtls1_read_bytes, SSL_R_BAD_CHANGE_CIPHER_SPEC);
goto f_err;
}
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);
}
/* We can't process a CCS now, because previous handshake
* messages are still missing, so just drop it.
*/
if (!s->d1->change_cipher_spec_ok) {
goto start;
}
s->d1->change_cipher_spec_ok = 0;
s->s3->change_cipher_spec = 1;
if (!ssl3_do_change_cipher_spec(s)) {
goto err;
}
/* do this whenever CCS is processed */
dtls1_reset_seq_numbers(s, SSL3_CC_READ);
goto start;
}
/* Unexpected handshake message. It may be a retransmitted Finished (the only
* post-CCS message). Otherwise, it's a pre-CCS handshake message from an
* unsupported renegotiation attempt. */
if (rr->type == SSL3_RT_HANDSHAKE && !s->in_handshake) {
if (rr->length < DTLS1_HM_HEADER_LENGTH) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_BAD_HANDSHAKE_RECORD);
goto f_err;
}
struct hm_header_st msg_hdr;
dtls1_get_message_header(&rr->data[rr->off], &msg_hdr);
/* Ignore a stray Finished from the previous handshake. */
if (msg_hdr.type == SSL3_MT_FINISHED) {
if (msg_hdr.frag_off == 0) {
/* Retransmit our last flight of messages. If the peer sends the second
* Finished, they may not have received ours. Only do this for the
* first fragment, in case the Finished was fragmented. */
if (dtls1_check_timeout_num(s) < 0) {
return -1;
}
dtls1_retransmit_buffered_messages(s);
}
rr->length = 0;
goto start;
}
}
/* We already handled these. */
assert(rr->type != SSL3_RT_CHANGE_CIPHER_SPEC && rr->type != SSL3_RT_ALERT);
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNEXPECTED_RECORD);
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
err:
return -1;
}
int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) {
int i;
if (SSL_in_init(s) && !s->in_handshake) {
i = s->handshake_func(s);
if (i < 0) {
return i;
}
if (i == 0) {
OPENSSL_PUT_ERROR(SSL, dtls1_write_app_data_bytes,
SSL_R_SSL_HANDSHAKE_FAILURE);
return -1;
}
}
if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
OPENSSL_PUT_ERROR(SSL, dtls1_write_app_data_bytes,
SSL_R_DTLS_MESSAGE_TOO_BIG);
return -1;
}
i = dtls1_write_bytes(s, type, buf_, len, dtls1_use_current_epoch);
return i;
}
/* 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 dtls1_write_bytes(SSL *s, int type, const void *buf, int len,
enum dtls1_use_epoch_t use_epoch) {
int i;
assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
s->rwstate = SSL_NOTHING;
i = do_dtls1_write(s, type, buf, len, use_epoch);
return i;
}
/* dtls1_seal_record seals a new record of type |type| and plaintext |in| and
* writes it to |out|. At most |max_out| bytes will be written. It returns one
* on success and zero on error. On success, it updates the write sequence
* number. */
static int dtls1_seal_record(SSL *s, uint8_t *out, size_t *out_len,
size_t max_out, uint8_t type, const uint8_t *in,
size_t in_len, enum dtls1_use_epoch_t use_epoch) {
if (max_out < DTLS1_RT_HEADER_LENGTH) {
OPENSSL_PUT_ERROR(SSL, dtls1_seal_record, SSL_R_BUFFER_TOO_SMALL);
return 0;
}
/* Determine the parameters for the current epoch. */
uint16_t epoch = s->d1->w_epoch;
SSL_AEAD_CTX *aead = s->aead_write_ctx;
uint8_t *seq = s->s3->write_sequence;
if (use_epoch == dtls1_use_previous_epoch) {
/* DTLS renegotiation is unsupported, so only epochs 0 (NULL cipher) and 1
* (negotiated cipher) exist. */
assert(s->d1->w_epoch == 1);
epoch = s->d1->w_epoch - 1;
aead = NULL;
seq = s->d1->last_write_sequence;
}
out[0] = type;
uint16_t wire_version = s->s3->have_version ? s->version : DTLS1_VERSION;
out[1] = wire_version >> 8;
out[2] = wire_version & 0xff;
out[3] = epoch >> 8;
out[4] = epoch & 0xff;
memcpy(&out[5], &seq[2], 6);
size_t ciphertext_len;
if (!SSL_AEAD_CTX_seal(aead, out + DTLS1_RT_HEADER_LENGTH, &ciphertext_len,
max_out - DTLS1_RT_HEADER_LENGTH, type, wire_version,
&out[3] /* seq */, in, in_len) ||
!ssl3_record_sequence_update(&seq[2], 6)) {
return 0;
}
if (ciphertext_len >= 1 << 16) {
OPENSSL_PUT_ERROR(SSL, dtls1_seal_record, ERR_R_OVERFLOW);
return 0;
}
out[11] = ciphertext_len >> 8;
out[12] = ciphertext_len & 0xff;
*out_len = DTLS1_RT_HEADER_LENGTH + ciphertext_len;
if (s->msg_callback) {
s->msg_callback(1 /* write */, 0, SSL3_RT_HEADER, out,
DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
}
return 1;
}
static int do_dtls1_write(SSL *s, int type, const uint8_t *buf,
unsigned int len, enum dtls1_use_epoch_t use_epoch) {
SSL3_BUFFER *wb = &s->s3->wbuf;
/* ssl3_write_pending drops the write if |BIO_write| fails in DTLS, so there
* is never pending data. */
assert(s->s3->wbuf.left == 0);
/* 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 (wb->buf == NULL && !ssl3_setup_write_buffer(s)) {
return -1;
}
if (len == 0) {
return 0;
}
/* Align the output so the ciphertext is aligned to |SSL3_ALIGN_PAYLOAD|. */
uintptr_t align = (uintptr_t)wb->buf + DTLS1_RT_HEADER_LENGTH;
align = (0 - align) & (SSL3_ALIGN_PAYLOAD - 1);
uint8_t *out = wb->buf + align;
wb->offset = align;
size_t max_out = wb->len - wb->offset;
size_t ciphertext_len;
if (!dtls1_seal_record(s, out, &ciphertext_len, max_out, type, buf, len,
use_epoch)) {
return -1;
}
/* now let's set up wb */
wb->left = 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);
}
static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) {
int cmp;
unsigned int shift;
const uint8_t *seq = s->s3->read_sequence;
cmp = satsub64be(seq, bitmap->max_seq_num);
if (cmp > 0) {
memcpy(s->s3->rrec.seq_num, seq, 8);
return 1; /* this record in new */
}
shift = -cmp;
if (shift >= sizeof(bitmap->map) * 8) {
return 0; /* stale, outside the window */
} else if (bitmap->map & (((uint64_t)1) << shift)) {
return 0; /* record previously received */
}
memcpy(s->s3->rrec.seq_num, seq, 8);
return 1;
}
static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) {
int cmp;
unsigned int shift;
const uint8_t *seq = s->s3->read_sequence;
cmp = satsub64be(seq, bitmap->max_seq_num);
if (cmp > 0) {
shift = cmp;
if (shift < sizeof(bitmap->map) * 8) {
bitmap->map <<= shift, bitmap->map |= 1UL;
} else {
bitmap->map = 1UL;
}
memcpy(bitmap->max_seq_num, seq, 8);
} else {
shift = -cmp;
if (shift < sizeof(bitmap->map) * 8) {
bitmap->map |= ((uint64_t)1) << shift;
}
}
}
int dtls1_dispatch_alert(SSL *s) {
int i, j;
void (*cb)(const SSL *ssl, int type, int val) = NULL;
uint8_t buf[DTLS1_AL_HEADER_LENGTH];
uint8_t *ptr = &buf[0];
s->s3->alert_dispatch = 0;
memset(buf, 0x00, sizeof(buf));
*ptr++ = s->s3->send_alert[0];
*ptr++ = s->s3->send_alert[1];
i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf),
dtls1_use_current_epoch);
if (i <= 0) {
s->s3->alert_dispatch = 1;
} else {
if (s->s3->send_alert[0] == SSL3_AL_FATAL) {
(void)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;
}
void dtls1_reset_seq_numbers(SSL *s, int rw) {
uint8_t *seq;
unsigned int seq_bytes = sizeof(s->s3->read_sequence);
if (rw & SSL3_CC_READ) {
seq = s->s3->read_sequence;
s->d1->r_epoch++;
memset(&s->d1->bitmap, 0, sizeof(DTLS1_BITMAP));
} else {
seq = s->s3->write_sequence;
memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
s->d1->w_epoch++;
}
memset(seq, 0x00, seq_bytes);
}