Re: [Linphone-developers] Testing AES3 with EC and B256 on Android

[Johan Pascal]

Hi Peter,
for EC it's perfectly normal, it had not been implemented yet. DH2k and 
DH3k(default) are the only key agreement available in bzrtp even if 
linphone won't complain if you set EC in your config file.

For SAS rendering and block ciphering, it's more surprising.

From your log it looks like the configuration is never found as the log 
shall mention it right after the Configured srtp crypto suite part. Can 
you send me the complete log file please? Did you insert the 
zrtp_XXX_suites settings in the sip section of the config file?

I plan to include a more accurate trace on the ZRTP negotiation(complete 
set of algo used) and it may even make its way to the GUI at least on 
the desktop version for now. I'll keep you updated on this.

regards,

Johan


On 25/04/15 21:00, Peter Villeneuve wrote:
> Hi guys,
>
> I just downloaded latest git and compiled from scratch.
>
> I have applied to my linphonerc_factory the following configs taken from
> here
> https://lists.gnu.org/archive/html/linphone-developers/2015-03/msg00022.html
>
> At the end of my linphonerc_factory I have added
>
> zrtp_key_agreements_suites=MS_ZRTP_KEY_AGREEMENT_EC38
> zrtp_cipher_suites=MS_ZRTP_CIPHER_AES3
> zrtp_auth_suites=MS_ZRTP_AUTHTAG_HS80
> zrtp_hash_suites=MS_ZRTP_HASH_S256
> zrtp_sas_suites=MS_ZRTP_SAS_B256
>
>
> So far so good. Everything compiles fine and when I run the apk on two
> different phones I'm able to establish audio and negotiate ZRTP as expected.
>
> However, I have enabled debugging and looking through logcat it seems
> that the cipher suite used is still AES1. Also, the key negotiation
> seems to be DH instead of EC.
>
> Here are the relevant bits from the logfile:
>
> 04-25 17:14:09.609 I/linphone(5863): Configured srtp crypto suite:
> AES_CM_128_HMAC_SHA1_80
> 04-25 17:14:09.609 I/linphone(5863): Configured srtp crypto suite:
> AES_CM_128_HMAC_SHA1_32
> 04-25 17:14:09.609 I/linphone(5863): Configured srtp crypto suite:
> AES_CM_256_HMAC_SHA1_80
> 04-25 17:14:09.609 I/linphone(5863): Configured srtp crypto suite:
> AES_CM_256_HMAC_SHA1_32
> 04-25 17:14:09.609 I/linphone(5863): Creating ZRTP engine on rtp session
> [0x582de150]
>
>
> and later after the call is established and the key is negotiated:
>
> 04-25 17:14:11.484 I/linphone(5863): New call state [UpdatedByRemote]
> 04-25 17:14:11.484 I/linphone(5863): ZRTP Receive packet type DHPart2
> 04-25 17:14:11.544 I/linphone(5863): ZRTP Send packet type Confirm1 on
> rtp session [0x582de150]
> 04-25 17:14:11.544 W/linphone(5863): MSAudio MSTicker: We are late of 54
> miliseconds.
> 04-25 17:14:11.559 I/linphone(5863): ZRTP Receive packet type DHPart2
> 04-25 17:14:11.564 I/linphone(5863): ZRTP Send packet type Confirm1 on
> rtp session [0x582de150]
> 04-25 17:14:11.574 I/linphone(5863): ZRTP Receive packet type Confirm2
> 04-25 17:14:11.574 I/linphone(5863): ZRTP secrets are ready for
> receiver; *auth tag algo is HS80 and cipher algo is AES128*
> 04-25 17:14:11.574 I/linphone(5863): media_stream_set_srtp_recv_key():
> key 45..a2 stream sessions is [0x58e0be98]
> 04-25 17:14:11.574 I/linphone(5863): media_stream_set_srtcp_recv_key():
> key 45..a2 stream sessions is [0x58e0be98]
> 04-25 17:14:11.574 I/linphone(5863): ZRTP Send packet type Conf2ACK on
> rtp session [0x582de150]
> 04-25 17:14:11.579 I/linphone(5863): ZRTP secrets are ready for sender;
> auth tag algo is HS80 and cipher algo is AES128
> 04-25 17:14:11.579 I/linphone(5863): media_stream_set_srtp_send_key():
> key da..8e stream sessions is [0x58e0be98]
> 04-25 17:14:11.579 I/linphone(5863): media_stream_set_srtcp_send_key():
> key da..8e stream sessions is [0x58e0be98]
> 04-25 17:14:11.579 I/linphone(5863): ZRTP secrets on: SAS is g5hm
> previously verified yes
> 04-25 17:14:11.579 I/linphone(5863): Event dispatched to all: secrets are on
> 04-25 17:14:11.579 E/linphone(5863): srtp_unprotect() failed (7) on
> stream ctx [0x589d4860]
>
>
> As you can see, even though I installed the apk on both phones, it seems
> linphone still chooses to use AES 128 with DH and SAS is still using 4
> character SAS instead of B256.
> Am I doing anything wrong? How can I test out AES3 and EC with B256 SAS?
> It would be great if we could see in the call's UI some info regarding
> what type of algo was negotiated so we don't have to enable debugging
> and look through the logs to find out this useful info.
>
> Thoughts?
>
> Cheers,
>
> Peter
>
>
>
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