bass Posted March 6, 2015 Share Posted March 6, 2015 Hi,I just try to capture GSMTAP packets from my OpenBTS. unfortunately I could not get SMS content as plain text. anybody know how to figure out this problem?some sources said with standart wireshark they could get content sms in plain text. I had tried to copy its hex stream and decode with 7bit encoder which was provided online, but the result was same, I got nothing.Many Thanks,Bass Quote Link to comment Share on other sites More sharing options...
bass Posted March 6, 2015 Author Share Posted March 6, 2015 this is the print screen.. thnks Quote Link to comment Share on other sites More sharing options...
cooper Posted March 6, 2015 Share Posted March 6, 2015 I was under the impression that GSM typically used some level of encryption for its transports. Did you deactivate/not configure this for your OpenBTS 'tower'? Maybe something for a separate thread, but could you describe your setup? What you're doing here sounds really fascinating. Quote Link to comment Share on other sites More sharing options...
digip Posted March 6, 2015 Share Posted March 6, 2015 (edited) Unless you can force it to lower bands, 3g and above generally I believe are encrypted. 2g and lower bands I believe can be read more easily though. Google Georgia Weidman for some of her videos on capturing phone traffic. https://secupwn.github.io/Android-IMSI-Catcher-Detector/ Edited March 6, 2015 by digip Quote Link to comment Share on other sites More sharing options...
bass Posted March 9, 2015 Author Share Posted March 9, 2015 hi cooper,I used default configuration on my openBTS. only changing the GSMTAP config with "1" to enable wireshark for capturing the openbts packets.here is its pcap file :https://drive.google.com/open?id=0B2PfFt7P5kAgcjJaQUNBeVFuMGM&authuser=0 hi digip,what I know is openbts run on 2G not 3G. then, open encryption also optional, in this case my configuration is "GSM.Cipher.Encrypt 0" (default, without encryption). Quote Link to comment Share on other sites More sharing options...
bass Posted March 9, 2015 Author Share Posted March 9, 2015 anyway, I have send this issue to ask.wireshark also. they said that TP-data malformed. but still confuse, how come, because i used "fresh" openbts installation and without any chnges the parameter, except gsmtap fiture. is there anyone here ever capture messge over OpenBTS before? some of tutorial I saw, could get it as plain text also without any changing on its configurations.. Quote Link to comment Share on other sites More sharing options...
digip Posted March 9, 2015 Share Posted March 9, 2015 (edited) You may need an additional plugin or settings enabled, but wireshark should be capable of reading the unencrypted 2G data. Try display filter gsm_map.ms.sai_Present but if you already see the data and malformed, I'm thinking it may be still encrypted or something else not setup properly. http://wiki.wireshark.org/GsmProtocolFamily Edited March 9, 2015 by digip Quote Link to comment Share on other sites More sharing options...
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