[asterisk-bugs] [JIRA] (ASTERISK-22961) [patch] DTLS-SRTP not working with SHA-256

[JoshE (JIRA)]

    [ https://issues.asterisk.org/jira/browse/ASTERISK-22961?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=217636#comment-217636 ] 

JoshE commented on ASTERISK-22961:
----------------------------------

I just got a chance to look at this again.  I see the same RTP packet size you did @jag, but that's a red herring.

The issue here now appears to be ICE candidate negotiation on Asterisk.  I am seeing Chrome stuck in the following:

ICEConnectionStateChecking

And a PCAP on the WebRTC client shows a loop of ICE Binding requests and responses.  The net of it is that Chrome isn't ever sending RTP, because it isn't in the proper state.  I applied 

As another note, I am testing with dev/beta Chrome 36/35, which no longer have fallback support by default for SDES, so DTLS-SRTP is going to be needed soon.  This required another SIP patch to pass the crypto flag properly when the SDP only contains the m=audio 38517 RTP/SAVPF line.

Josh

> [patch] DTLS-SRTP not working with SHA-256
> ------------------------------------------
>
>                 Key: ASTERISK-22961
>                 URL: https://issues.asterisk.org/jira/browse/ASTERISK-22961
>             Project: Asterisk
>          Issue Type: Improvement
>      Security Level: None
>          Components: Channels/chan_sip/SRTP, Channels/chan_sip/WebSocket
>    Affects Versions: 11.6.0, 12.0.0-beta2
>            Reporter: Jay Jideliov
>         Attachments: 11.7 patched.zip, asterisk_dtls.patch, backtrace (1).txt, chan_sip.c, dtls_retransmission.patch, ice_session.c, jssip no ring.txt, res_rtp_asterisk.c, res_rtp_asterisk.c, srtp_dtls.patch, srtp_dtls.patch, wireshark.txt
>
>
> Recently it became possible to use websocket on asterisk without a proxy previously necessary to make calls from the web browser. Although partial support has been added, full browser cross-operability has not been achieved yet. However, it seems to be a relatively easy task.
> Tested on Chrome+SIPML5+Asterisk 11, the connection can be established and works fine. However, due to the fact that Firefox sends SHA-256 packets which are not supported by asterisk, hence the support for this browser is limited by this issue.
> Step 1: Adding certificates to support DTLS
> dtlsenable = yes
> dtlsverify = no
> dtlscertfile=/etc/asterisk/keys/softphone.pem
> dtlsprivatekey=/etc/asterisk/keys/key.pem
> dtlscafile=/etc/asterisk/keys/key.pem
> Step 2: Making a call
> [Nov 25 15:05:50] WARNING[5628][C-0000005c]: chan_sip.c:11034 process_sdp_a_dtls: Unsupported fingerprint hash type 'sha-2' received on dialog '38f43a1f-15cd-ad69-c2b3-72c21b9de5fd'



--
This message was sent by Atlassian JIRA
(v6.2#6252)