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openssl/ssl/record/rec_layer_d1.c

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/*
* Copyright 2005-2021 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include <errno.h>
#include "../ssl_local.h"
#include <openssl/evp.h>
#include <openssl/buffer.h>
#include "record_local.h"
#include "../packet_local.h"
#include "internal/cryptlib.h"
int DTLS_RECORD_LAYER_new(RECORD_LAYER *rl)
{
DTLS_RECORD_LAYER *d;
if ((d = OPENSSL_malloc(sizeof(*d))) == NULL) {
SSLerr(SSL_F_DTLS_RECORD_LAYER_NEW, ERR_R_MALLOC_FAILURE);
return 0;
}
rl->d = d;
d->unprocessed_rcds.q = pqueue_new();
d->processed_rcds.q = pqueue_new();
d->buffered_app_data.q = pqueue_new();
if (d->unprocessed_rcds.q == NULL || d->processed_rcds.q == NULL
|| d->buffered_app_data.q == NULL) {
pqueue_free(d->unprocessed_rcds.q);
pqueue_free(d->processed_rcds.q);
pqueue_free(d->buffered_app_data.q);
OPENSSL_free(d);
rl->d = NULL;
return 0;
}
return 1;
}
void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl)
{
if (rl->d == NULL)
return;
DTLS_RECORD_LAYER_clear(rl);
pqueue_free(rl->d->unprocessed_rcds.q);
pqueue_free(rl->d->processed_rcds.q);
pqueue_free(rl->d->buffered_app_data.q);
OPENSSL_free(rl->d);
rl->d = NULL;
}
void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl)
{
DTLS_RECORD_LAYER *d;
pitem *item = NULL;
DTLS1_RECORD_DATA *rdata;
pqueue *unprocessed_rcds;
pqueue *processed_rcds;
pqueue *buffered_app_data;
d = rl->d;
while ((item = pqueue_pop(d->unprocessed_rcds.q)) != NULL) {
rdata = (DTLS1_RECORD_DATA *)item->data;
OPENSSL_free(rdata->rbuf.buf);
OPENSSL_free(item->data);
pitem_free(item);
}
while ((item = pqueue_pop(d->processed_rcds.q)) != NULL) {
rdata = (DTLS1_RECORD_DATA *)item->data;
OPENSSL_free(rdata->rbuf.buf);
OPENSSL_free(item->data);
pitem_free(item);
}
while ((item = pqueue_pop(d->buffered_app_data.q)) != NULL) {
rdata = (DTLS1_RECORD_DATA *)item->data;
OPENSSL_free(rdata->rbuf.buf);
OPENSSL_free(item->data);
pitem_free(item);
}
unprocessed_rcds = d->unprocessed_rcds.q;
processed_rcds = d->processed_rcds.q;
buffered_app_data = d->buffered_app_data.q;
memset(d, 0, sizeof(*d));
d->unprocessed_rcds.q = unprocessed_rcds;
d->processed_rcds.q = processed_rcds;
d->buffered_app_data.q = buffered_app_data;
}
void DTLS_RECORD_LAYER_set_saved_w_epoch(RECORD_LAYER *rl, unsigned short e)
{
if (e == rl->d->w_epoch - 1) {
memcpy(rl->d->curr_write_sequence,
rl->write_sequence, sizeof(rl->write_sequence));
memcpy(rl->write_sequence,
rl->d->last_write_sequence, sizeof(rl->write_sequence));
} else if (e == rl->d->w_epoch + 1) {
memcpy(rl->d->last_write_sequence,
rl->write_sequence, sizeof(unsigned char[8]));
memcpy(rl->write_sequence,
rl->d->curr_write_sequence, sizeof(rl->write_sequence));
}
rl->d->w_epoch = e;
}
void DTLS_RECORD_LAYER_set_write_sequence(RECORD_LAYER *rl, unsigned char *seq)
{
memcpy(rl->write_sequence, seq, SEQ_NUM_SIZE);
}
/* copy buffered record into SSL structure */
static int dtls1_copy_record(SSL *s, pitem *item)
{
DTLS1_RECORD_DATA *rdata;
rdata = (DTLS1_RECORD_DATA *)item->data;
SSL3_BUFFER_release(&s->rlayer.rbuf);
s->rlayer.packet = rdata->packet;
s->rlayer.packet_length = rdata->packet_length;
memcpy(&s->rlayer.rbuf, &(rdata->rbuf), sizeof(SSL3_BUFFER));
memcpy(&s->rlayer.rrec, &(rdata->rrec), sizeof(SSL3_RECORD));
/* Set proper sequence number for mac calculation */
memcpy(&(s->rlayer.read_sequence[2]), &(rdata->packet[5]), 6);
return 1;
}
int dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
{
DTLS1_RECORD_DATA *rdata;
pitem *item;
/* Limit the size of the queue to prevent DOS attacks */
if (pqueue_size(queue->q) >= 100)
return 0;
rdata = OPENSSL_malloc(sizeof(*rdata));
item = pitem_new(priority, rdata);
if (rdata == NULL || item == NULL) {
OPENSSL_free(rdata);
pitem_free(item);
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_BUFFER_RECORD,
ERR_R_INTERNAL_ERROR);
return -1;
}
rdata->packet = s->rlayer.packet;
rdata->packet_length = s->rlayer.packet_length;
memcpy(&(rdata->rbuf), &s->rlayer.rbuf, sizeof(SSL3_BUFFER));
memcpy(&(rdata->rrec), &s->rlayer.rrec, sizeof(SSL3_RECORD));
item->data = rdata;
#ifndef OPENSSL_NO_SCTP
/* Store bio_dgram_sctp_rcvinfo struct */
if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
(SSL_get_state(s) == TLS_ST_SR_FINISHED
|| SSL_get_state(s) == TLS_ST_CR_FINISHED)) {
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
sizeof(rdata->recordinfo), &rdata->recordinfo);
}
#endif
s->rlayer.packet = NULL;
s->rlayer.packet_length = 0;
memset(&s->rlayer.rbuf, 0, sizeof(s->rlayer.rbuf));
memset(&s->rlayer.rrec, 0, sizeof(s->rlayer.rrec));
if (!ssl3_setup_buffers(s)) {
/* SSLfatal() already called */
OPENSSL_free(rdata->rbuf.buf);
OPENSSL_free(rdata);
pitem_free(item);
return -1;
}
if (pqueue_insert(queue->q, item) == NULL) {
/* Must be a duplicate so ignore it */
OPENSSL_free(rdata->rbuf.buf);
OPENSSL_free(rdata);
pitem_free(item);
}
return 1;
}
int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
{
pitem *item;
item = pqueue_pop(queue->q);
if (item) {
dtls1_copy_record(s, item);
OPENSSL_free(item->data);
pitem_free(item);
return 1;
}
return 0;
}
/*
* retrieve a buffered record that belongs to the new epoch, i.e., not
* processed yet
*/
#define dtls1_get_unprocessed_record(s) \
dtls1_retrieve_buffered_record((s), \
&((s)->rlayer.d->unprocessed_rcds))
int dtls1_process_buffered_records(SSL *s)
{
pitem *item;
SSL3_BUFFER *rb;
SSL3_RECORD *rr;
DTLS1_BITMAP *bitmap;
unsigned int is_next_epoch;
int replayok = 1;
item = pqueue_peek(s->rlayer.d->unprocessed_rcds.q);
if (item) {
/* Check if epoch is current. */
if (s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch)
return 1; /* Nothing to do. */
rr = RECORD_LAYER_get_rrec(&s->rlayer);
rb = RECORD_LAYER_get_rbuf(&s->rlayer);
if (SSL3_BUFFER_get_left(rb) > 0) {
/*
* We've still got data from the current packet to read. There could
* be a record from the new epoch in it - so don't overwrite it
* with the unprocessed records yet (we'll do it when we've
* finished reading the current packet).
*/
return 1;
}
/* Process all the records. */
while (pqueue_peek(s->rlayer.d->unprocessed_rcds.q)) {
dtls1_get_unprocessed_record(s);
bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
if (bitmap == NULL) {
/*
* Should not happen. This will only ever be NULL when the
* current record is from a different epoch. But that cannot
* be the case because we already checked the epoch above
*/
SSLfatal(s, SSL_AD_INTERNAL_ERROR,
SSL_F_DTLS1_PROCESS_BUFFERED_RECORDS,
ERR_R_INTERNAL_ERROR);
return 0;
}
#ifndef OPENSSL_NO_SCTP
/* Only do replay check if no SCTP bio */
if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
#endif
{
/*
* Check whether this is a repeat, or aged record. We did this
* check once already when we first received the record - but
* we might have updated the window since then due to
* records we subsequently processed.
*/
replayok = dtls1_record_replay_check(s, bitmap);
}
if (!replayok || !dtls1_process_record(s, bitmap)) {
if (ossl_statem_in_error(s)) {
/* dtls1_process_record called SSLfatal() */
return -1;
}
/* dump this record */
rr->length = 0;
RECORD_LAYER_reset_packet_length(&s->rlayer);
continue;
}
if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds),
SSL3_RECORD_get_seq_num(s->rlayer.rrec)) < 0) {
/* SSLfatal() already called */
return 0;
}
}
}
/*
* sync epoch numbers once all the unprocessed records have been
* processed
*/
s->rlayer.d->processed_rcds.epoch = s->rlayer.d->r_epoch;
s->rlayer.d->unprocessed_rcds.epoch = s->rlayer.d->r_epoch + 1;
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) or renegotiation requests. ChangeCipherSpec
* messages are treated as if they were handshake messages *if* the |recd_type|
* argument is non NULL.
* 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, int *recvd_type, unsigned char *buf,
size_t len, int peek, size_t *readbytes)
{
int i, j, iret;
size_t n;
SSL3_RECORD *rr;
void (*cb) (const SSL *ssl, int type2, int val) = NULL;
if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) {
/* Not initialized yet */
if (!ssl3_setup_buffers(s)) {
/* SSLfatal() already called */
return -1;
}
}
if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
(type != SSL3_RT_HANDSHAKE)) ||
(peek && (type != SSL3_RT_APPLICATION_DATA))) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_READ_BYTES,
ERR_R_INTERNAL_ERROR);
return -1;
}
if (!ossl_statem_get_in_handshake(s) && SSL_in_init(s)) {
/* type == SSL3_RT_APPLICATION_DATA */
i = s->handshake_func(s);
/* SSLfatal() already called if appropriate */
if (i < 0)
return i;
if (i == 0)
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->rlayer.rrec;
/*
* We are not handshaking and have no data yet, so process data buffered
* during the last handshake in advance, if any.
*/
if (SSL_is_init_finished(s) && SSL3_RECORD_get_length(rr) == 0) {
pitem *item;
item = pqueue_pop(s->rlayer.d->buffered_app_data.q);
if (item) {
#ifndef OPENSSL_NO_SCTP
/* Restore bio_dgram_sctp_rcvinfo struct */
if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
sizeof(rdata->recordinfo), &rdata->recordinfo);
}
#endif
dtls1_copy_record(s, item);
OPENSSL_free(item->data);
pitem_free(item);
}
}
/* Check for timeout */
if (dtls1_handle_timeout(s) > 0) {
goto start;
} else if (ossl_statem_in_error(s)) {
/* dtls1_handle_timeout() has failed with a fatal error */
return -1;
}
/* get new packet if necessary */
if ((SSL3_RECORD_get_length(rr) == 0)
|| (s->rlayer.rstate == SSL_ST_READ_BODY)) {
RECORD_LAYER_set_numrpipes(&s->rlayer, 0);
iret = dtls1_get_record(s);
if (iret <= 0) {
iret = dtls1_read_failed(s, iret);
/*
* Anything other than a timeout is an error. SSLfatal() already
* called if appropriate.
*/
if (iret <= 0)
return iret;
else
goto start;
}
RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
}
/*
* Reset the count of consecutive warning alerts if we've got a non-empty
* record that isn't an alert.
*/
if (SSL3_RECORD_get_type(rr) != SSL3_RT_ALERT
&& SSL3_RECORD_get_length(rr) != 0)
s->rlayer.alert_count = 0;
/* we now have a packet which can be read and processed */
if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
* reset by ssl3_get_finished */
&& (SSL3_RECORD_get_type(rr) != SSL3_RT_HANDSHAKE)) {
/*
* We now have application data between CCS and Finished. Most likely
* the packets were reordered on their way, so buffer the application
* data for later processing rather than dropping the connection.
*/
if (dtls1_buffer_record(s, &(s->rlayer.d->buffered_app_data),
SSL3_RECORD_get_seq_num(rr)) < 0) {
/* SSLfatal() already called */
return -1;
}
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
goto start;
}
/*
* If the other end has shut down, throw anything we read away (even in
* 'peek' mode)
*/
if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
s->rwstate = SSL_NOTHING;
return 0;
}
if (type == SSL3_RECORD_get_type(rr)
|| (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC
&& type == SSL3_RT_HANDSHAKE && recvd_type != NULL)) {
/*
* SSL3_RT_APPLICATION_DATA or
* SSL3_RT_HANDSHAKE or
* SSL3_RT_CHANGE_CIPHER_SPEC
*/
/*
* 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->enc_read_ctx == NULL)) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
SSL_R_APP_DATA_IN_HANDSHAKE);
return -1;
}
if (recvd_type != NULL)
*recvd_type = SSL3_RECORD_get_type(rr);
if (len == 0) {
/*
* Mark a zero length record as read. This ensures multiple calls to
* SSL_read() with a zero length buffer will eventually cause
* SSL_pending() to report data as being available.
*/
if (SSL3_RECORD_get_length(rr) == 0)
SSL3_RECORD_set_read(rr);
return 0;
}
if (len > SSL3_RECORD_get_length(rr))
n = SSL3_RECORD_get_length(rr);
else
n = len;
memcpy(buf, &(SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)]), n);
if (peek) {
if (SSL3_RECORD_get_length(rr) == 0)
SSL3_RECORD_set_read(rr);
} else {
SSL3_RECORD_sub_length(rr, n);
SSL3_RECORD_add_off(rr, n);
if (SSL3_RECORD_get_length(rr) == 0) {
s->rlayer.rstate = SSL_ST_READ_HEADER;
SSL3_RECORD_set_off(rr, 0);
SSL3_RECORD_set_read(rr);
}
}
#ifndef OPENSSL_NO_SCTP
/*
* We might had to delay a close_notify alert because of reordered
* app data. If there was an alert and there is no message to read
* anymore, finally set shutdown.
*/
if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
s->d1->shutdown_received
&& !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
s->shutdown |= SSL_RECEIVED_SHUTDOWN;
return 0;
}
#endif
*readbytes = n;
return 1;
}
/*
* If we get here, then type != rr->type; if we have a handshake message,
* then it was unexpected (Hello Request or Client Hello).
*/
if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) {
unsigned int alert_level, alert_descr;
unsigned char *alert_bytes = SSL3_RECORD_get_data(rr)
+ SSL3_RECORD_get_off(rr);
PACKET alert;
if (!PACKET_buf_init(&alert, alert_bytes, SSL3_RECORD_get_length(rr))
|| !PACKET_get_1(&alert, &alert_level)
|| !PACKET_get_1(&alert, &alert_descr)
|| PACKET_remaining(&alert) != 0) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
SSL_R_INVALID_ALERT);
return -1;
}
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_ALERT, alert_bytes, 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 = (alert_level << 8) | alert_descr;
cb(s, SSL_CB_READ_ALERT, j);
}
if (alert_level == SSL3_AL_WARNING) {
s->s3->warn_alert = alert_descr;
SSL3_RECORD_set_read(rr);
s->rlayer.alert_count++;
if (s->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
SSL_R_TOO_MANY_WARN_ALERTS);
return -1;
}
if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
#ifndef OPENSSL_NO_SCTP
/*
* With SCTP and streams the socket may deliver app data
* after a close_notify alert. We have to check this first so
* that nothing gets discarded.
*/
if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
s->d1->shutdown_received = 1;
s->rwstate = SSL_READING;
BIO_clear_retry_flags(SSL_get_rbio(s));
BIO_set_retry_read(SSL_get_rbio(s));
return -1;
}
#endif
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;
SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_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;
SSL3_RECORD_set_read(rr);
SSL_CTX_remove_session(s->session_ctx, s->session);
return 0;
} else {
SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_DTLS1_READ_BYTES,
SSL_R_UNKNOWN_ALERT_TYPE);
return -1;
}
goto start;
}
if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
* shutdown */
s->rwstate = SSL_NOTHING;
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
return 0;
}
if (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC) {
/*
* We can't process a CCS now, because previous handshake messages
* are still missing, so just drop it.
*/
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
goto start;
}
/*
* Unexpected handshake message (Client Hello, or protocol violation)
*/
if ((SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) &&
!ossl_statem_get_in_handshake(s)) {
struct hm_header_st msg_hdr;
/*
* This may just be a stale retransmit. Also sanity check that we have
* at least enough record bytes for a message header
*/
if (SSL3_RECORD_get_epoch(rr) != s->rlayer.d->r_epoch
|| SSL3_RECORD_get_length(rr) < DTLS1_HM_HEADER_LENGTH) {
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
goto start;
}
dtls1_get_message_header(rr->data, &msg_hdr);
/*
* If we are server, we may have a repeated FINISHED of the client
* here, then retransmit our CCS and FINISHED.
*/
if (msg_hdr.type == SSL3_MT_FINISHED) {
if (dtls1_check_timeout_num(s) < 0) {
/* SSLfatal) already called */
return -1;
}
if (dtls1_retransmit_buffered_messages(s) <= 0) {
/* Fail if we encountered a fatal error */
if (ossl_statem_in_error(s))
return -1;
}
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
/* no read-ahead left? */
BIO *bio;
s->rwstate = SSL_READING;
bio = SSL_get_rbio(s);
BIO_clear_retry_flags(bio);
BIO_set_retry_read(bio);
return -1;
}
}
goto start;
}
/*
* To get here we must be trying to read app data but found handshake
* data. But if we're trying to read app data, and we're not in init
* (which is tested for at the top of this function) then init must be
* finished
*/
if (!ossl_assert(SSL_is_init_finished(s))) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_READ_BYTES,
ERR_R_INTERNAL_ERROR);
return -1;
}
/* We found handshake data, so we're going back into init */
ossl_statem_set_in_init(s, 1);
i = s->handshake_func(s);
/* SSLfatal() called if appropriate */
if (i < 0)
return i;
if (i == 0)
return -1;
if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
/* no read-ahead left? */
BIO *bio;
/*
* In the case where we try to read application data, but we
* trigger an SSL handshake, we return -1 with the retry
* option set. Otherwise renegotiation may cause nasty
* problems in the blocking world
*/
s->rwstate = SSL_READING;
bio = SSL_get_rbio(s);
BIO_clear_retry_flags(bio);
BIO_set_retry_read(bio);
return -1;
}
}
goto start;
}
switch (SSL3_RECORD_get_type(rr)) {
default:
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
SSL_R_UNEXPECTED_RECORD);
return -1;
case SSL3_RT_CHANGE_CIPHER_SPEC:
case SSL3_RT_ALERT:
case SSL3_RT_HANDSHAKE:
/*
* we already handled all of these, with the possible exception of
* SSL3_RT_HANDSHAKE when ossl_statem_get_in_handshake(s) is true, but
* that should not happen when type != rr->type
*/
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
ERR_R_INTERNAL_ERROR);
return -1;
case SSL3_RT_APPLICATION_DATA:
/*
* At this point, we were expecting handshake data, but have
* application data. If the library was running inside ssl3_read()
* (i.e. in_read_app_data is set) and it makes sense to read
* application data at this point (session renegotiation not yet
* started), we will indulge it.
*/
if (s->s3->in_read_app_data &&
(s->s3->total_renegotiations != 0) &&
ossl_statem_app_data_allowed(s)) {
s->s3->in_read_app_data = 2;
return -1;
} else {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
SSL_R_UNEXPECTED_RECORD);
return -1;
}
}
/* not reached */
}
/*
* 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, size_t len,
size_t *written)
{
int i;
if (!ossl_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_WRITE_BYTES,
ERR_R_INTERNAL_ERROR);
return -1;
}
s->rwstate = SSL_NOTHING;
i = do_dtls1_write(s, type, buf, len, 0, written);
return i;
}
int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
size_t len, int create_empty_fragment, size_t *written)
{
unsigned char *p, *pseq;
int i, mac_size, clear = 0;
size_t prefix_len = 0;
int eivlen;
SSL3_RECORD wr;
SSL3_BUFFER *wb;
SSL_SESSION *sess;
wb = &s->rlayer.wbuf[0];
/*
* DTLS writes whole datagrams, so there can't be anything left in
* the buffer.
*/
if (!ossl_assert(SSL3_BUFFER_get_left(wb) == 0)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
ERR_R_INTERNAL_ERROR);
return 0;
}
/* If we have an alert to send, lets send it */
if (s->s3->alert_dispatch) {
i = s->method->ssl_dispatch_alert(s);
if (i <= 0)
return i;
/* if it went, fall through and send more stuff */
}
if (len == 0 && !create_empty_fragment)
return 0;
if (len > ssl_get_max_send_fragment(s)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE);
return 0;
}
sess = s->session;
if ((sess == NULL) ||
(s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
clear = 1;
if (clear)
mac_size = 0;
else {
mac_size = EVP_MD_CTX_size(s->write_hash);
if (mac_size < 0) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE);
return -1;
}
}
p = SSL3_BUFFER_get_buf(wb) + prefix_len;
/* write the header */
*(p++) = type & 0xff;
SSL3_RECORD_set_type(&wr, type);
/*
* Special case: for hello verify request, client version 1.0 and we
* haven't decided which version to use yet send back using version 1.0
* header: otherwise some clients will ignore it.
*/
if (s->method->version == DTLS_ANY_VERSION &&
s->max_proto_version != DTLS1_BAD_VER) {
*(p++) = DTLS1_VERSION >> 8;
*(p++) = DTLS1_VERSION & 0xff;
} else {
*(p++) = s->version >> 8;
*(p++) = s->version & 0xff;
}
/* field where we are to write out packet epoch, seq num and len */
pseq = p;
p += 10;
/* Explicit IV length, block ciphers appropriate version flag */
if (s->enc_write_ctx) {
int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
if (mode == EVP_CIPH_CBC_MODE) {
eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
if (eivlen <= 1)
eivlen = 0;
}
/* Need explicit part of IV for GCM mode */
else if (mode == EVP_CIPH_GCM_MODE)
eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
else if (mode == EVP_CIPH_CCM_MODE)
eivlen = EVP_CCM_TLS_EXPLICIT_IV_LEN;
else
eivlen = 0;
} else
eivlen = 0;
/* lets setup the record stuff. */
SSL3_RECORD_set_data(&wr, p + eivlen); /* make room for IV in case of CBC */
SSL3_RECORD_set_length(&wr, len);
SSL3_RECORD_set_input(&wr, (unsigned char *)buf);
/*
* we now 'read' from wr.input, wr.length bytes into wr.data
*/
/* first we compress */
if (s->compress != NULL) {
if (!ssl3_do_compress(s, &wr)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
SSL_R_COMPRESSION_FAILURE);
return -1;
}
} else {
memcpy(SSL3_RECORD_get_data(&wr), SSL3_RECORD_get_input(&wr),
SSL3_RECORD_get_length(&wr));
SSL3_RECORD_reset_input(&wr);
}
/*
* we should still have the output to wr.data and the input from
* wr.input. Length should be wr.length. wr.data still points in the
* wb->buf
*/
if (!SSL_WRITE_ETM(s) && mac_size != 0) {
if (!s->method->ssl3_enc->mac(s, &wr,
&(p[SSL3_RECORD_get_length(&wr) + eivlen]),
1)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
ERR_R_INTERNAL_ERROR);
return -1;
}
SSL3_RECORD_add_length(&wr, mac_size);
}
/* this is true regardless of mac size */
SSL3_RECORD_set_data(&wr, p);
SSL3_RECORD_reset_input(&wr);
if (eivlen)
SSL3_RECORD_add_length(&wr, eivlen);
if (s->method->ssl3_enc->enc(s, &wr, 1, 1) < 1) {
if (!ossl_statem_in_error(s)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
ERR_R_INTERNAL_ERROR);
}
return -1;
}
if (SSL_WRITE_ETM(s) && mac_size != 0) {
if (!s->method->ssl3_enc->mac(s, &wr,
&(p[SSL3_RECORD_get_length(&wr)]), 1)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
ERR_R_INTERNAL_ERROR);
return -1;
}
SSL3_RECORD_add_length(&wr, mac_size);
}
/* record length after mac and block padding */
/* there's only one epoch between handshake and app data */
s2n(s->rlayer.d->w_epoch, pseq);
memcpy(pseq, &(s->rlayer.write_sequence[2]), 6);
pseq += 6;
s2n(SSL3_RECORD_get_length(&wr), pseq);
if (s->msg_callback)
s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
/*
* we should now have wr.data pointing to the encrypted data, which is
* wr->length long
*/
SSL3_RECORD_set_type(&wr, type); /* not needed but helps for debugging */
SSL3_RECORD_add_length(&wr, DTLS1_RT_HEADER_LENGTH);
ssl3_record_sequence_update(&(s->rlayer.write_sequence[0]));
if (create_empty_fragment) {
/*
* we are in a recursive call; just return the length, don't write
* out anything here
*/
*written = wr.length;
return 1;
}
/* now let's set up wb */
SSL3_BUFFER_set_left(wb, prefix_len + SSL3_RECORD_get_length(&wr));
SSL3_BUFFER_set_offset(wb, 0);
/*
* memorize arguments so that ssl3_write_pending can detect bad write
* retries later
*/
s->rlayer.wpend_tot = len;
s->rlayer.wpend_buf = buf;
s->rlayer.wpend_type = type;
s->rlayer.wpend_ret = len;
/* we now just need to write the buffer. Calls SSLfatal() as required. */
return ssl3_write_pending(s, type, buf, len, written);
}
DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
unsigned int *is_next_epoch)
{
*is_next_epoch = 0;
/* In current epoch, accept HM, CCS, DATA, & ALERT */
if (rr->epoch == s->rlayer.d->r_epoch)
return &s->rlayer.d->bitmap;
/*
* Only HM and ALERT messages can be from the next epoch and only if we
* have already processed all of the unprocessed records from the last
* epoch
*/
else if (rr->epoch == (unsigned long)(s->rlayer.d->r_epoch + 1) &&
s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch &&
(rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
*is_next_epoch = 1;
return &s->rlayer.d->next_bitmap;
}
return NULL;
}
void dtls1_reset_seq_numbers(SSL *s, int rw)
{
unsigned char *seq;
unsigned int seq_bytes = sizeof(s->rlayer.read_sequence);
if (rw & SSL3_CC_READ) {
seq = s->rlayer.read_sequence;
s->rlayer.d->r_epoch++;
memcpy(&s->rlayer.d->bitmap, &s->rlayer.d->next_bitmap,
sizeof(s->rlayer.d->bitmap));
memset(&s->rlayer.d->next_bitmap, 0, sizeof(s->rlayer.d->next_bitmap));
/*
* We must not use any buffered messages received from the previous
* epoch
*/
dtls1_clear_received_buffer(s);
} else {
seq = s->rlayer.write_sequence;
memcpy(s->rlayer.d->last_write_sequence, seq,
sizeof(s->rlayer.write_sequence));
s->rlayer.d->w_epoch++;
}
memset(seq, 0, seq_bytes);
}
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