7 ms·

Extracting TLS keys from an unwilling application (2020)

• max1truc 4y ago
  • ArchOversight 4y ago
    Meta: it's on the front page now.
• jcalvinowens 4y ago
  Nice work! I'm curious: did you consider hacking the Oculus binary to accept an SSL cert you made yourself, and MITM-ing it to see the traffic? I'm sure they have it pinned and don't use the OS certs, but you could just overwrite the root cert that must exist in that binary somewhere with your own, right?
  • zevv 4y ago
    > but you could just overwrite the root cert that must exist in that binary somewhere with your own, right? Unless they use certificate pinning, which is basically just verifying the CA's are not tampered with. Theoretically that could be attacked as well, but it prevents the "just replace the CA" case.
    • _kbh_ 4y ago
      the attack here is to just invert the compares for all the checks, which means it'll accept any certificate thats not the original, then you can MitM all the traffic with only minor changes to the binary.
      • jcalvinowens 4y ago
        Finding the right branches to flip in the text seems a lot more time consuming than just replacing the cert data, which is probably in one place. Unless it's incredibly obfuscated or something...
        • deleted 4y ago
          [deleted]
        • _kbh_ 4y ago
          In hindsight this is probably a lot easier.
    • jcalvinowens 4y ago
      If they don't pin it's trivial. But I strongly suspect they do.
  • severino 4y ago
    > I'm curious: did you consider hacking the Oculus binary to accept an SSL cert you made yourself, and MITM-ing it to see the traffic? Is that what he refers to when he says "I didn’t want to add extra root certificates and proxies to inspect all TLS traffic going on the machine", or are we talking about different things?
    • jcalvinowens 4y ago
      Maybe? I don't understand why "proxies" and "certificates" are plural, you would need exactly one of each.
• randomhodler84 4y ago
  Another useful tool I have used in the past in windows is Nektra Deviare for function hooking. This is similar to the old Microsoft Detours framework, in that one can dynamically patch code in the running binary. I have used this to grab raw keys. https://www.nektra.com/products/deviare-api-hook-windows/ https://www.nektra.com/products/deviare-api-hook-windows/
• spidey1 4y ago
  Is there a similar tool that a non-security expert could use on the Mac?
  • chasil 4y ago
    If your application can also use clear text TCP sockets, then stunnel becomes an option.
  • K0nserv 4y ago
    Not sure about the non-security expert bit but I've done stuff[0] similar to this for iOS using Frida[1] which supports macOS too. For apps that use unpinned certificates and the builtin networking libraries(NSURLSession et.al.) you can directly use mimtproxy[2] or Charles[3] 0: https://hugotunius.se/2020/08/07/stealing-tls-sessions-keys-from-ios-apps.html https://hugotunius.se/2020/08/07/stealing-tls-sessions-keys-... 1: https://frida.re/ https://frida.re/ 2: https://mitmproxy.org/ https://mitmproxy.org/ 3: https://www.charlesproxy.com/ https://www.charlesproxy.com/
    • youngtaff 4y ago
      I think you need to disable SIP to get a Frida based approach to work on MacOS And while not MacOS this eBPF based approach is interesting https://mobile.twitter.com/quarkslab/status/1527726910997815296 https://mobile.twitter.com/quarkslab/status/1527726910997815...
  • matheusmoreira 4y ago
    If the application isn't pinning certificates, you should be able to add your own root certificate to your machine and intercept all encrypted traffic. Same method used by corporations to monitor their own networks. I successfully used this method on a mobile game years ago. Applications with pinned certificates don't use the system certificates at all which fixes the MITM vulnerability I described. You'd need to reverse engineer them in order to change the certificate to one under your control, difficulty can vary depending on how obfuscated the code is.
  • mr_mitm 4y ago
• funcDropShadow 4y ago
  If OpenSSL was under LGPL you could relink the Oculus software with a version of OpenSSL that supports exporting the keys.
  • bruce343434 4y ago
    You can still do that, but maybe not publish your method.
• kasane 4y ago
  What resources could I use to learn how to do this sort of work on my own initiative?