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Show HN: Snapception – Intercept all snapchats received over the network
41–50 of 84 posts
Re: Show HN: Snapception – Intercept all snapchats received over the network
#42If you can man in the middle traffic, aren't all authentication cookies compromised anyway?
Wouldn't any service then be subject to "interception"?
Re: Show HN: Snapception – Intercept all snapchats received over the network
#43I can't get this to work on my iPhone. When I visit mitm.it from my phone, or any other device, it redirects me to grit.io. How do I install the CA. I have the proxy up and running on my Macbook pro.
Re: Show HN: Snapception – Intercept all snapchats received over the network
#44Earlier quoted context omitted.
Not necessarily. If you control the gateway, it's possible to transparently redirect outbound connections into your proxy. I used to do this back in the 90s to force our employees browsers through an ad-blocking proxy. Depending on your user base (kids?), it could be as simple as setting up an open wifi access point in a place where all other APs are password-locked. Edit: I just realized that this proxy requires the…
Yes, but they would be clued in because the SSL certificate wouldn't be valid unless they trust your CA.
That's pretty trivial for parents. "Hey pumpkin, I need to borrow your phone for a second". That said this is something that maybe 0.1% of parents could or would set up.
Re: Show HN: Snapception – Intercept all snapchats received over the network
#45If you can man in the middle traffic, aren't all authentication cookies compromised anyway? Wouldn't any service then be subject to "interception"?
Not with proper encryption, I believe? In this case you can get someone else's supposedly private snaps if they're on your network, because the key is the same as the one for decrypting your snaps.
Re: Show HN: Snapception – Intercept all snapchats received over the network
#46But snapchat updated its encryption just a couple of days ago: https://github.com/programa-stic/snapchat-decrypt You will need the android id of the phone, which I don't think you can easily get as a man in the middle?
Ooh, I didn't even to think to test it on Android phones. This method works on iOS devices, however.
Re: Show HN: Snapception – Intercept all snapchats received over the network
#47Connecting via a proxy and installing a CA means this is more of a tool for a snooping parent to intercept the snapchats of their kids while they are at home, rather than a scary-looking tool for intercepting the general stream of snaps (as it is made out to be).
Not necessarily. If you control the gateway, it's possible to transparently redirect outbound connections into your proxy. I used to do this back in the 90s to force our employees browsers through an ad-blocking proxy. Depending on your user base (kids?), it could be as simple as setting up an open wifi access point in a place where all other APs are password-locked. Edit: I just realized that this proxy requires the…
If Mallory can install an arbitrary root certificate on Alice’s client, M can do nearly whatever she wants with A’s client.
Re: Show HN: Snapception – Intercept all snapchats received over the network
#48Earlier quoted context omitted.
Not necessarily. If you control the gateway, it's possible to transparently redirect outbound connections into your proxy. I used to do this back in the 90s to force our employees browsers through an ad-blocking proxy. Depending on your user base (kids?), it could be as simple as setting up an open wifi access point in a place where all other APs are password-locked. Edit: I just realized that this proxy requires the…
Yes, but they would be clued in because the SSL certificate wouldn't be valid unless they trust your CA.
Have you met a teenager? They will blindly just click ignore/ok until they can do what they want. an invalid cert error isn't going to stop them unless it actually blocks (rather than warns and lets them proceed)
Re: Show HN: Snapception – Intercept all snapchats received over the network
#49Snapchat use ECB as the cipher mode of operation: https://github.com/thebradbain/snapception/blob/781ebb13cd7e... To see why this is a problem, see the ECB-encrypted Tux image on http://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#... Oops.
To be fair, that demo only works on an uncompressed bitmap image with large areas of solid color. It relies on the fact that identical input blocks encrypt to identical outputs, leading to visible repeating patterns. In a format like JPEG, which has an entropy-coding stage and all kinds of internal headers, the chance of encountering two identical blocks in a file is miniscule. Of course ECB is still a very bad choic…
I don't know a lot about the specifics of JPG file format, but... with a complex file format you can probably make some educated guesses about the content of some of the blocks and perhaps start building up a sort of dictionary... ?
Yeah, ECB is BAD.
Re: Show HN: Snapception – Intercept all snapchats received over the network
#50If you can man in the middle traffic, aren't all authentication cookies compromised anyway? Wouldn't any service then be subject to "interception"?
Not with proper encryption, I believe? In this case you can get someone else's supposedly private snaps if they're on your network, because the key is the same as the one for decrypting your snaps.
Correct. Properly set up TLS should protect you regardless of MITMs.
The issue comes if someone can get you to accept their CA. In both this case and for MITM attacks on TLS. At that point it's game over.