diff options
author | Dr. Stephen Henson <steve@openssl.org> | 2009-04-02 22:32:16 +0000 |
---|---|---|
committer | Dr. Stephen Henson <steve@openssl.org> | 2009-04-02 22:32:16 +0000 |
commit | 4e319926d7cb80313d37105b5545fcce28fdddc1 (patch) | |
tree | 553e3a74b6bcc17d8ba9a40036280d8006ed7e9f /ssl/d1_both.c | |
parent | e4f456918f8c6ccf3ed43c36bdedf57e5c907b01 (diff) |
PR: 1828
Submitted by: Robin Seggelmann <seggelmann@fh-muenster.de>
Approved by: steve@openssl.org
Fix DTLS retransmission bug.
Diffstat (limited to 'ssl/d1_both.c')
-rw-r--r-- | ssl/d1_both.c | 75 |
1 files changed, 67 insertions, 8 deletions
diff --git a/ssl/d1_both.c b/ssl/d1_both.c index 5475cc73e8..c4590b872c 100644 --- a/ssl/d1_both.c +++ b/ssl/d1_both.c @@ -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; + /* 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, epoch<<16 | frag->msg_header.seq); + 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)); |