Micro.blog

aaronpk
aaronpk
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.
sirshannon
sirshannon

@aaronpk Message size?

In reply to
sirshannon
sirshannon

@aaronpk I probably know even less :)

nitinkhanna
nitinkhanna

@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

oyam
oyam

@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
oyam

@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?).

aaronpk
aaronpk

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

aaronpk
aaronpk

@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.

sirshannon
sirshannon

@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...

nitinkhanna
nitinkhanna

@sirshannon Charles? Some sort of packet sniffer?

jeff_mcfadden
jeff_mcfadden

@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...

aaronpk
aaronpk

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

sirshannon
sirshannon

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

nitinkhanna
nitinkhanna

@sirshannon ooh looks nice! Thanks for the link.

aaronpk
aaronpk

@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... 🤔

aaronpk
aaronpk

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