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PR: 1828

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Submitted by: Robin Seggelmann <seggelmann@fh-muenster.de>
Approved by: steve@openssl.org

Fix DTLS retransmission bug.
This commit is contained in:
Dr. Stephen Henson
2009-04-02 22:32:16 +00:00
parent e4f456918f
commit 4e319926d7
4 changed files with 101 additions and 10 deletions
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77
ssl/d1_both.c
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@@ -136,7 +136,6 @@ static unsigned char *dtls1_write_message_header(SSL *s,
static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
unsigned long len, unsigned short seq_num, unsigned long frag_off,
unsigned long frag_len);
static int dtls1_retransmit_buffered_messages(SSL *s);
static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
long max, int *ok);
@@ -943,8 +942,21 @@ int dtls1_read_failed(SSL *s, int code)
return dtls1_retransmit_buffered_messages(s) ;
}
int
dtls1_get_queue_priority(unsigned short seq, int is_ccs)
{
/* The index of the retransmission queue actually is the message sequence number,
* since the queue only contains messages of a single handshake. However, the
* ChangeCipherSpec has no message sequence number and so using only the sequence
* will result in the CCS and Finished having the same index. To prevent this,
* the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
* This does not only differ CSS and Finished, it also maintains the order of the
* index (important for priority queues) and fits in the unsigned short variable.
*/
return seq * 2 - is_ccs;
}
static int
int
dtls1_retransmit_buffered_messages(SSL *s)
{
pqueue sent = s->d1->sent_messages;
@@ -958,8 +970,9 @@ dtls1_retransmit_buffered_messages(SSL *s)
for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
{
frag = (hm_fragment *)item->data;
if ( dtls1_retransmit_message(s, frag->msg_header.seq, 0, &found) <= 0 &&
found)
if ( dtls1_retransmit_message(s,
dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
0, &found) <= 0 && found)
{
fprintf(stderr, "dtls1_retransmit_message() failed\n");
return -1;
@@ -975,7 +988,6 @@ dtls1_buffer_message(SSL *s, int is_ccs)
pitem *item;
hm_fragment *frag;
PQ_64BIT seq64;
unsigned int epoch = s->d1->w_epoch;
/* this function is called immediately after a message has
* been serialized */
@@ -989,7 +1001,6 @@ dtls1_buffer_message(SSL *s, int is_ccs)
{
OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num);
epoch++;
}
else
{
@@ -1004,9 +1015,19 @@ dtls1_buffer_message(SSL *s, int is_ccs)
frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
frag->msg_header.is_ccs = is_ccs;
pq_64bit_init(&seq64);
pq_64bit_assign_word(&seq64, epoch<<16 | frag->msg_header.seq);
/* save current state*/
frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
frag->msg_header.saved_retransmit_state.compress = s->compress;
frag->msg_header.saved_retransmit_state.session = s->session;
frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
pq_64bit_init(&seq64);
pq_64bit_assign_word(&seq64,
dtls1_get_queue_priority(frag->msg_header.seq,
frag->msg_header.is_ccs));
item = pitem_new(seq64, frag);
pq_64bit_free(&seq64);
if ( item == NULL)
@@ -1035,6 +1056,8 @@ dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
hm_fragment *frag ;
unsigned long header_length;
PQ_64BIT seq64;
struct dtls1_retransmit_state saved_state;
unsigned char save_write_sequence[8];
/*
OPENSSL_assert(s->init_num == 0);
@@ -1070,9 +1093,45 @@ dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
frag->msg_header.msg_len, frag->msg_header.seq, 0,
frag->msg_header.frag_len);
/* save current state */
saved_state.enc_write_ctx = s->enc_write_ctx;
saved_state.write_hash = s->write_hash;
saved_state.compress = s->compress;
saved_state.session = s->session;
saved_state.epoch = s->d1->w_epoch;
saved_state.epoch = s->d1->w_epoch;
s->d1->retransmitting = 1;
/* restore state in which the message was originally sent */
s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
s->compress = frag->msg_header.saved_retransmit_state.compress;
s->session = frag->msg_header.saved_retransmit_state.session;
s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
{
memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
}
ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
/* restore current state */
s->enc_write_ctx = saved_state.enc_write_ctx;
s->write_hash = saved_state.write_hash;
s->compress = saved_state.compress;
s->session = saved_state.session;
s->d1->w_epoch = saved_state.epoch;
if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
{
memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
}
s->d1->retransmitting = 0;
(void)BIO_flush(SSL_get_wbio(s));