/* 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;
}
int dtls1_read_app_data(SSL *ssl, uint8_t *buf, int len, int peek) {
return dtls1_read_bytes(ssl, SSL3_RT_APPLICATION_DATA, buf, len, peek);
}
void dtls1_read_close_notify(SSL *ssl) {
dtls1_read_bytes(ssl, 0, NULL, 0, 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 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(SSL *s, 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, SSL_R_SSL_HANDSHAKE_FAILURE);
return -1;
}
}
if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
OPENSSL_PUT_ERROR(SSL, dtls1_write_app_data, SSL_R_DTLS_MESSAGE_TOO_BIG);
return -1;
}
i = dtls1_write_bytes(s, SSL3_RT_APPLICATION_DATA, 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);
}