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openssl/ssl/record/rec_layer_d1.c
Matt Caswell c7f47786a5 Move state machine knowledge out of the record layer 
The record layer was making decisions that should really be left to the
state machine around unexpected handshake messages that are received after
the initial handshake (i.e. renegotiation related messages). This commit
removes that code from the record layer and updates the state machine
accordingly. This simplifies the state machine and paves the way for
handling other messages post-handshake such as the NewSessionTicket in
TLSv1.3.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2259)
2017-01-30 10:17:00 +00:00

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/*
* Copyright 2005-2016 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>
#define USE_SOCKETS
#include "../ssl_locl.h"
#include <openssl/evp.h>
#include <openssl/buffer.h>
#include "record_locl.h"
#include <assert.h>
int DTLS_RECORD_LAYER_new(RECORD_LAYER *rl)
{
DTLS_RECORD_LAYER *d;
if ((d = OPENSSL_malloc(sizeof(*d))) == NULL)
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)
{
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_resync_write(RECORD_LAYER *rl)
{
memcpy(rl->write_sequence, rl->read_sequence, sizeof(rl->write_sequence));
}
void DTLS_RECORD_LAYER_set_write_sequence(RECORD_LAYER *rl, unsigned char *seq)
{
memcpy(rl->write_sequence, seq, SEQ_NUM_SIZE);
}
static size_t have_handshake_fragment(SSL *s, int type, unsigned char *buf,
size_t len);
/* 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);
SSLerr(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)) {
SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
OPENSSL_free(rdata->rbuf.buf);
OPENSSL_free(rdata);
pitem_free(item);
return (-1);
}
/* insert should not fail, since duplicates are dropped */
if (pqueue_insert(queue->q, item) == NULL) {
SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
OPENSSL_free(rdata->rbuf.buf);
OPENSSL_free(rdata);
pitem_free(item);
return (-1);
}
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
*/
SSLerr(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)) {
/* 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)
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 al, i, j, iret;
size_t ret, 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))
return (-1);
}
if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
(type != SSL3_RT_HANDSHAKE)) ||
(peek && (type != SSL3_RT_APPLICATION_DATA))) {
SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
return -1;
}
/*
* check whether there's a handshake message (client hello?) waiting
*/
ret = have_handshake_fragment(s, type, buf, len);
if (ret > 0) {
*recvd_type = SSL3_RT_HANDSHAKE;
*readbytes = ret;
return 1;
}
/*
* Now s->rlayer.d->handshake_fragment_len == 0 if
* type == SSL3_RT_HANDSHAKE.
*/
#ifndef OPENSSL_NO_SCTP
/*
* Continue handshake if it had to be interrupted to read app data with
* SCTP.
*/
if ((!ossl_statem_get_in_handshake(s) && SSL_in_init(s)) ||
(BIO_dgram_is_sctp(SSL_get_rbio(s))
&& ossl_statem_in_sctp_read_sock(s)
&& s->s3->in_read_app_data != 2))
#else
if (!ossl_statem_get_in_handshake(s) && SSL_in_init(s))
#endif
{
/* type == SSL3_RT_APPLICATION_DATA */
i = s->handshake_func(s);
if (i < 0)
return i;
if (i == 0) {
SSLerr(SSL_F_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->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;
/* get new packet if necessary */
if ((SSL3_RECORD_get_length(rr) == 0)
|| (s->rlayer.rstate == SSL_ST_READ_BODY)) {
iret = dtls1_get_record(s);
if (iret <= 0) {
iret = dtls1_read_failed(s, iret);
/* anything other than a timeout is an error */
if (iret <= 0)
return iret;
else
goto start;
}
}
/*
* 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) {
SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
return -1;
}
SSL3_RECORD_set_length(rr, 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) {
SSL3_RECORD_set_length(rr, 0);
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)) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
goto f_err;
}
if (recvd_type != NULL)
*recvd_type = SSL3_RECORD_get_type(rr);
if (len == 0)
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) {
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);
}
}
#ifndef OPENSSL_NO_SCTP
/*
* We were about to renegotiate but had to read belated application
* data first, so retry.
*/
if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
SSL3_RECORD_get_type(rr) == SSL3_RT_APPLICATION_DATA &&
ossl_statem_in_sctp_read_sock(s)) {
s->rwstate = SSL_READING;
BIO_clear_retry_flags(SSL_get_rbio(s));
BIO_set_retry_read(SSL_get_rbio(s));
}
/*
* 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).
*/
/*
* In case of record types for which we have 'fragment' storage, fill
* that so that we can process the data at a fixed place.
*/
{
size_t k, dest_maxlen = 0;
unsigned char *dest = NULL;
size_t *dest_len = NULL;
if (SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) {
dest_maxlen = sizeof s->rlayer.d->handshake_fragment;
dest = s->rlayer.d->handshake_fragment;
dest_len = &s->rlayer.d->handshake_fragment_len;
} else if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) {
dest_maxlen = sizeof(s->rlayer.d->alert_fragment);
dest = s->rlayer.d->alert_fragment;
dest_len = &s->rlayer.d->alert_fragment_len;
}
/* else it's a CCS message, or application data or wrong */
else if (SSL3_RECORD_get_type(rr) != SSL3_RT_CHANGE_CIPHER_SPEC) {
/*
* Application data while renegotiating is allowed. Try again
* reading.
*/
if (SSL3_RECORD_get_type(rr) == SSL3_RT_APPLICATION_DATA) {
BIO *bio;
s->s3->in_read_app_data = 2;
bio = SSL_get_rbio(s);
s->rwstate = SSL_READING;
BIO_clear_retry_flags(bio);
BIO_set_retry_read(bio);
return -1;
}
/* Not certain if this is the right error handling */
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
goto f_err;
}
if (dest_maxlen > 0) {
/*
* XDTLS: In a pathological case, the Client Hello may be
* fragmented--don't always expect dest_maxlen bytes
*/
if (SSL3_RECORD_get_length(rr) < dest_maxlen) {
#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
/*
* for normal alerts rr->length is 2, while
* dest_maxlen is 7 if we were to handle this
* non-existing alert...
*/
FIX ME;
#endif
s->rlayer.rstate = SSL_ST_READ_HEADER;
SSL3_RECORD_set_length(rr, 0);
goto start;
}
/* now move 'n' bytes: */
for (k = 0; k < dest_maxlen; k++) {
dest[k] = SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)];
SSL3_RECORD_add_off(rr, 1);
SSL3_RECORD_add_length(rr, -1);
}
*dest_len = dest_maxlen;
}
}
/*-
* s->rlayer.d->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
* s->rlayer.d->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
* (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
*/
if (s->rlayer.d->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
int alert_level = s->rlayer.d->alert_fragment[0];
int alert_descr = s->rlayer.d->alert_fragment[1];
s->rlayer.d->alert_fragment_len = 0;
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_ALERT,
s->rlayer.d->alert_fragment, 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;
s->rlayer.alert_count++;
if (s->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_TOO_MANY_WARN_ALERTS);
goto f_err;
}
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;
}
#if 0
/* XXX: this is a possible improvement in the future */
/* now check if it's a missing record */
if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
unsigned short seq;
unsigned int frag_off;
unsigned char *p = &(s->rlayer.d->alert_fragment[2]);
n2s(p, seq);
n2l3(p, frag_off);
dtls1_retransmit_message(s,
dtls1_get_queue_priority
(frag->msg_header.seq, 0), frag_off,
&found);
if (!found && SSL_in_init(s)) {
/*
* fprintf( stderr,"in init = %d\n", SSL_in_init(s));
*/
/*
* requested a message not yet sent, send an alert
* ourselves
*/
ssl3_send_alert(s, SSL3_AL_WARNING,
DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
}
}
#endif
} else if (alert_level == SSL3_AL_FATAL) {
char tmp[16];
s->rwstate = SSL_NOTHING;
s->s3->fatal_alert = alert_descr;
SSLerr(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;
SSL_CTX_remove_session(s->session_ctx, s->session);
return 0;
} else {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_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;
SSL3_RECORD_set_length(rr, 0);
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);
goto start;
}
/*
* Unexpected handshake message (Client Hello, or protocol violation)
*/
if ((s->rlayer.d->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
!ossl_statem_get_in_handshake(s)) {
struct hm_header_st msg_hdr;
/* this may just be a stale retransmit */
dtls1_get_message_header(rr->data, &msg_hdr);
if (SSL3_RECORD_get_epoch(rr) != s->rlayer.d->r_epoch) {
SSL3_RECORD_set_length(rr, 0);
goto start;
}
/*
* 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)
return -1;
dtls1_retransmit_buffered_messages(s);
SSL3_RECORD_set_length(rr, 0);
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
*/
assert(SSL_is_init_finished(s));
if (!SSL_is_init_finished(s)) {
al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
goto f_err;
}
/* We found handshake data, so we're going back into init */
ossl_statem_set_in_init(s, 1);
i = s->handshake_func(s);
if (i < 0)
return i;
if (i == 0) {
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
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:
/* TLS just ignores unknown message types */
if (s->version == TLS1_VERSION) {
SSL3_RECORD_set_length(rr, 0);
goto start;
}
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
goto f_err;
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
*/
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
goto f_err;
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 {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
goto f_err;
}
}
/* not reached */
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return -1;
}
/*
* this only happens when a client hello is received and a handshake
* is started.
*/
static size_t have_handshake_fragment(SSL *s, int type, unsigned char *buf,
size_t len)
{
if ((type == SSL3_RT_HANDSHAKE)
&& (s->rlayer.d->handshake_fragment_len > 0))
/* (partially) satisfy request from storage */
{
unsigned char *src = s->rlayer.d->handshake_fragment;
unsigned char *dst = buf;
size_t k, n;
/* peek == 0 */
n = 0;
while ((len > 0) && (s->rlayer.d->handshake_fragment_len > 0)) {
*dst++ = *src++;
len--;
s->rlayer.d->handshake_fragment_len--;
n++;
}
/* move any remaining fragment bytes: */
for (k = 0; k < s->rlayer.d->handshake_fragment_len; k++)
s->rlayer.d->handshake_fragment[k] = *src++;
return n;
}
return 0;
}
/*
* 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;
OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
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];
/*
* first check if there is a SSL3_BUFFER still being written out. This
* will happen with non blocking IO
*/
if (SSL3_BUFFER_get_left(wb) != 0) {
OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
return ssl3_write_pending(s, type, buf, len, written);
}
/* 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;
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)
goto err;
}
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)) {
SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
goto err;
}
} 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_USE_ETM(s) && mac_size != 0) {
if (!s->method->ssl3_enc->mac(s, &wr,
&(p[SSL3_RECORD_get_length(&wr) + eivlen]),
1))
goto err;
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)
goto err;
if (SSL_USE_ETM(s) && mac_size != 0) {
if (!s->method->ssl3_enc->mac(s, &wr,
&(p[SSL3_RECORD_get_length(&wr)]), 1))
goto err;
SSL3_RECORD_add_length(&wr, mac_size);
}
/* record length after mac and block padding */
/*
* if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
* SSL_in_init(s)))
*/
/* there's only one epoch between handshake and app data */
s2n(s->rlayer.d->w_epoch, pseq);
/* XDTLS: ?? */
/*
* else s2n(s->d1->handshake_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 */
return ssl3_write_pending(s, type, buf, len, written);
err:
return -1;
}
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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