diff options
| author | Holger Hans Peter Freyther <holger@moiji-mobile.com> | 2014-06-24 10:57:35 +0200 |
|---|---|---|
| committer | Holger Hans Peter Freyther <holger@moiji-mobile.com> | 2014-06-24 10:59:43 +0200 |
| commit | bf6f1f4a37c254f5046de555092b8c0b8c0940a6 (patch) | |
| tree | c678dfda2b2f81248cf58e36dc32095adaed0c30 | |
| parent | d67f3f04ab59e766521b234bff6b40be21f279ff (diff) | |
rtp: Randomize the initial sequence number for RFC compliance
The usage of random() is not that unpredictable but the closest
we can get right now.
RFC 3550:
The initial value of the sequence number SHOULD be random
(unpredictable) to make known-plaintext attacks on encryption
more difficult, even if the source itself does not encrypt
according to the method in Section 9.1, because the packets
may flow through a translator that does. Techniques for
choosing unpredictable numbers are discussed in [17].
Fixes: SYS#403
| -rw-r--r-- | src/trau/osmo_ortp.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/trau/osmo_ortp.c b/src/trau/osmo_ortp.c index 2f2f26c..89a69ee 100644 --- a/src/trau/osmo_ortp.c +++ b/src/trau/osmo_ortp.c @@ -337,6 +337,10 @@ struct osmo_rtp_socket *osmo_rtp_socket_create(void *talloc_ctx, unsigned int fl (RtpCallback) ortp_sig_cb_ts, (unsigned long) rs); + /* initialize according to the RFC */ + rtp_session_set_seq_number(rs->sess, random()); + + return rs; } |