Don't use the buffer BIO in DTLS.
Instead, "writing" a message merely adds it to the outgoing_messages
structure. The code to write the flight then loops over it all and now
shares code with retransmission. The verbs here are all a little odd,
but they'll be fixed in later commits.
In doing so, this fixes a slight miscalculation of the record-layer
overhead when retransmitting a flight that spans two epochs. (We'd use
the encrypted epoch's overhead for the unencrypted epoch.)
BUG=72
Change-Id: I8ac897c955cc74799f8b5ca6923906e97d6dad17
Reviewed-on: https://boringssl-review.googlesource.com/13223
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/internal.h b/ssl/internal.h
index a320e72..ffe4d62 100644
--- a/ssl/internal.h
+++ b/ssl/internal.h
@@ -433,6 +433,10 @@
dtls1_use_current_epoch,
};
+/* dtls_max_seal_overhead returns the maximum overhead, in bytes, of sealing a
+ * record. */
+size_t dtls_max_seal_overhead(const SSL *ssl, enum dtls1_use_epoch_t use_epoch);
+
/* dtls_seal_prefix_len returns the number of bytes of prefix to reserve in
* front of the plaintext when sealing a record in-place. */
size_t dtls_seal_prefix_len(const SSL *ssl, enum dtls1_use_epoch_t use_epoch);
@@ -1645,6 +1649,13 @@
DTLS_OUTGOING_MESSAGE outgoing_messages[SSL_MAX_HANDSHAKE_FLIGHT];
uint8_t outgoing_messages_len;
+ /* outgoing_written is the number of outgoing messages that have been
+ * written. */
+ uint8_t outgoing_written;
+ /* outgoing_offset is the number of bytes of the next outgoing message have
+ * been written. */
+ uint32_t outgoing_offset;
+
unsigned int mtu; /* max DTLS packet size */
/* num_timeouts is the number of times the retransmit timer has fired since
@@ -1779,6 +1790,8 @@
size_t *out_len);
int dtls1_queue_message(SSL *ssl, uint8_t *msg, size_t len);
int dtls1_write_message(SSL *ssl);
+int dtls1_send_change_cipher_spec(SSL *ssl);
+int dtls1_flush_flight(SSL *ssl);
/* ssl_complete_message calls |finish_message| and |queue_message| on |cbb| to
* queue the message for writing. */
@@ -1805,7 +1818,6 @@
int dtls1_write_record(SSL *ssl, int type, const uint8_t *buf, size_t len,
enum dtls1_use_epoch_t use_epoch);
-int dtls1_send_change_cipher_spec(SSL *ssl);
int dtls1_send_finished(SSL *ssl, int a, int b, const char *sender, int slen);
int dtls1_retransmit_outgoing_messages(SSL *ssl);
void dtls1_clear_record_buffer(SSL *ssl);
