Ok legit question: How is @Gogo able to block sending and receiving photos in iMessage? I thought iMessage was end-to-end encrypted so it shouldn't have any visibility into what type of content is being sent over that channel.

@aaronpk Message size?

@aaronpk I probably know even less :)

@aaronpk I don't think they're looking at the packet but maybe iMessage has a different endpoint to which images get uploaded and that's blocked? They could very well have taken Apple's approval and blessings to do this, since that's their business plan. // @sirshannon

@aaronpk Is maybe iMessages falling back on SMS? If there is no support for MMS, images would be left behind, and only text making it through.

@oyam @aaronpk Gogo recommends turning off iMessages in their guide, so I’d assume it has to do with that. It’s probably causing iMessages to fail completely and iMessages is falling back to SMS (unless you had that explicitly disabled?).

@oyam Nope I don't use a phone number with iMessage and all the bubbles are still blue.

@oyam Actually wait no, SMS won't work at all in airplane mode because it disables the cell antenna. Gogo has a mode that explicitly enables iMessage, but without photos.

@nitinkhanna @aaronpk Dart throw guess number 2: port 80 is allowed but not all of the iMessage ports? Maybe we should crank up Charles and test this...

@aaronpk I would guess they're looking at traffic patterns and just dropping packets that match what they think are files being sent. Similar to how mobile carriers attempt to enforce limits on supported video resolution for data streamed over HTTPS security.stackexchange.com/questions...

@jeff_mcfadden ahhh that is an excellent read, thanks!!

@nitinkhanna yeah. Charles Proxy: www.charlesproxy.com

@sirshannon ooh looks nice! Thanks for the link.

@sirshannon I guess I'm confused because I can upload photos to my website over https just fine but somehow photos in iMessage are blocked... 🤔

@sirshannon I guess? I don't know enough about the protocol and where the encryption happens to understand how that works.