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• Non-RSA TLS1.2 Packet decryption

  7 février 2017, par Joseph Wahba

  I am trying to decrypt a pcap file. This pcap file contains a capture of an HLS encrypted video stream. The pcap contains TLSv1.2 packets.

  Below are some information from the pcap file

  Server Hello message Cipher Suite :

  TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384.

  EC Diffie-Hellman server Params : pubkey (1)

  The Certificate Status message :

  Signature Hash Algorithm Hash : SHA256

  Signature Hash Algorithm Signature : ECDSA

  Client Key Exchange Message

  EC Diffie-Hellman server Params : pubkey (2)

  I tried to follow this Wireshark SSL decryption tutorial. But it seems that it works only for RSA encryptions.
  I have been researching for a while and found this discussion. I am quoting an extract from this discussion :

  There is an important parameter to mind : decryption of a passively
  recorded session (with a copy of the server private key) works only if
  the key exchange was of type RSA or static DH ; with "DHE" and "ECDHE"
  cipher suites, you won’t be able to decrypt such a session, even with
  knowledge of the server private key. In that case, you will need
  either the negotiated "master secret", or to use the server private
  key to actively intercept the connection

  It’s note worthy that I have the client private key. In my case, the client is FFmpeg video streamer (FFplay). I had a look also on the TLS v1.2 RFC.

  My question :

  Is it possible to do a decryption in this scenario ? If yes, what do I need to have to do so ?

  Is the decryption done using the client’s private key or using the pre_shared_master (i.e. Diffie-Hellman) ?

• Revision 36891 : On liste les codecs gérés...

  3 avril 2010, par kent1@… — Log

  On liste les codecs gérés…

• PHP - Read and write the same file hangs

  2 février 2016, par Adracat

  I’m trying to use FFMPEG to make some works with video on the server, and something I need to do is to get the progress of the process.

  I searched a little and I found this solution which tells to write the log into a file and then reading and parsing it.

  The problem

  What is driving me crazy is that I tell FFMPEG - with exec - (process A) to write the log into a file, but when I try to read it - with file_get_contents() - (process B) it does not show the contents until process A is finished (or interrupted the PHP script).

  So, when process A finishes or it says "PHP script timeout", then I can read the file as times as I want, refreshing the page (process B) and showing the contents at the time.

  What I’ve tried

  I’ve tried to use fopen() to create the file with w, w+ and a parameters, using - and without using - fclose(). I’ve tried to use also flock() just in case it gets faster to read to process B if it knows it’s already locked and does not have to wait, but then FFMPEG is not able to write into the file.

  I’ve searched for multithreading too, but I think there must be an easier and simpler way.

  I’ve used also CURL and HTTP context, as this link suggests, but no luck.

  I’ve tried, too, to use PHP-FFMPEG but it’s not supporting the last FFMPEG version, so I cannot use it.

  When I said before "(or interrupted the PHP script)" is because I tried to wait and, when PHP got a timeout, process B worked alright and the file was still updating.

  The code

  Process A (fileA.php)

  exec('ffmpeg -y -i input_file.mp4 output_file.avi 2> C:\Full\Path\To\File\log.txt 1>&2');

  Process B (fileB.php)

  $content = file_get_contents($file);
  
  
  
  if($content){
  
      //get duration of source
  
      preg_match("/Duration: (.*?), start:/", $content, $matches);
  
  
  
      $rawDuration = $matches[1];
  
  
  
      //rawDuration is in 00:00:00.00 format. This converts it to seconds.
  
      $ar = array_reverse(explode(":", $rawDuration));
  
      $duration = floatval($ar[0]);
  
      if (!empty($ar[1])) $duration += intval($ar[1]) * 60;
  
      if (!empty($ar[2])) $duration += intval($ar[2]) * 60 * 60;
  
  
  
      //get the time in the file that is already encoded
  
      preg_match_all("/time=(.*?) bitrate/", $content, $matches);
  
  
  
      $rawTime = array_pop($matches);
  
  
  
      //this is needed if there is more than one match
  
      if (is_array($rawTime)){$rawTime = array_pop($rawTime);}
  
  
  
      //rawTime is in 00:00:00.00 format. This converts it to seconds.
  
      $ar = array_reverse(explode(":", $rawTime));
  
      $time = floatval($ar[0]);
  
      if (!empty($ar[1])) $time += intval($ar[1]) * 60;
  
      if (!empty($ar[2])) $time += intval($ar[2]) * 60 * 60;
  
  
  
      //calculate the progress
  
      $progress = round(($time/$duration) * 100);
  
  
  
      echo "Duration: " . $duration . "<br />";
  
      echo "Current Time: " . $time . "<br />";
  
      echo "Progress: " . $progress . "%";
  
  
  
  }

  The process

  I just open fileA.php on a Chrome tab and, after a few seconds, I open fileB.php on another Chrome tab (and it stays as loading).

  What I need

  I need to be able to load the file and show the information I want to show while the file is being written (by exec and FFMPEG or other PHP scripts), so I can update the progress percentage with some AJAX calls.

  Extra information

  At this point, I’m using PHP 5.4 on a IIS 7.5 with Windows 7 Professional.

  Thank you everyone for your time, help and patience !

  Best regards.