Changes between Version 5 and Version 6 of doc/OONI/censorshipwiki/CensorshipByCountry/Ethiopia


Ignore:
Timestamp:
Jul 19, 2012, 1:29:02 PM (6 years ago)
Author:
phw
Comment:

Added information about the 3 blocked public bridges and manufactorer.

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  • doc/OONI/censorshipwiki/CensorshipByCountry/Ethiopia

    v5 v6  
    1 
    21----
    32== Ethiopia (#6045) ==
    4 
    53=== Summary of the current situation ===
    64DPI boxes look for Tor TLS server hellos sent by relays or bridges to Tor clients. If such a packet is found, it is dropped. The DPI boxes seem to operate in-band and stateless.
     
    1412=== Type of Tor censorship ===
    1513 * '''Deep packet inspection''': #6045
    16   * '''Fingerprint''': Multiple strings in the Tor TLS ServerHello/Certificate/ServerKeyExchange/ServerHelloDone records are matched (#6045). If a packet matches, it is dropped.
     14   * '''Fingerprint''': Multiple strings in the Tor TLS ServerHello/Certificate/ServerKeyExchange/ServerHelloDone records are matched (#6045). If a packet matches, it is dropped.
    1715
    1816=== Types of non-Tor censorship ===
     
    2018
    2119=== Ways to bypass censorship ===
    22  * Bridges were patched to pick the cipher `TLS_DHE_RSA_WITH_AES_128_CBC_SHA` instead of `TLS_DHE_RSA_WITH_AES_256_CBC_SHA`. This was sufficient to evade the DPI boxes. Three patched bridges were published in a [https://blog.torproject.org/blog/update-censorship-ethiopia blog post].
     20 * Bridges were patched to pick the cipher `TLS_DHE_RSA_WITH_AES_128_CBC_SHA` instead of `TLS_DHE_RSA_WITH_AES_256_CBC_SHA`. This was sufficient to evade the DPI boxes. Three patched bridges were published in a [https://blog.torproject.org/blog/update-censorship-ethiopia blog post]. However, all three bridges became useless at the beginning of July 2012. They appear to be blocked on the IP layer.
    2321 * [https://www.torproject.org/projects/obfsproxy.html.en Obfsproxy] probably evades the DPI boxes too.
    2422
    2523=== Type of firewall ===
    26  * '''Manufactorer''': nothing definitive, possibly something from ZTE Corp.
     24 * '''Manufactorer''': nothing definitive, possibly something from ZTE Corp. It is hard to narrow down the DPI boxes because traceroutes get dropped somewhere in the network backbone.
    2725
    2826=== Reproducing the blocking ===