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Am I reading this right? If WhatsApp and similar are no longer able to implement End-To-End crypto because they have to use an Apple API which supports only spe

Am I reading this right? If WhatsApp and similar are no longer able to implement End-To-End crypto because they have to use an Apple API which supports only specific protocols, this is going to be a huge loss for users. I've considered switching to an iOS device, but stuff like this keeps me away, I'm very glad I can keep direct SIP, SSH, IMAP and XMPP connections open at all hours of the day.

EGreg 7y ago
Doesn’t he mention explicitly in the video that you can use standard notifications and decrypt the payload before showing them? How exactly do you deliver notifications in Android? Can background apps simply listen on an open websocket or something?? What exactly is your technique on android
- eridius 7y ago
  I haven't watched the video, but Apple has a notifications API specifically for encrypted messaging apps to receive encrypted notifications and run a notification appex that decrypts the notification payload prior to showing the notification to the user.
fourthark 7y ago
It wasn't clear why they are using VoIP for WhatsApp. Sounded like it was because it allowed more background processing? I doubt they would ban end to end crypto, but you are right, it is more of a locked down system. Edit: keep reading. People explain this nicely below.
dep_b 7y ago
Not being able to lurk in the background does not have anything to do with security. I don’t think Signal uses it and they’re generally considered secure. You can check out their source.
- auslander 7y ago
  Signal docs say it needs Background permission : "Without this, there may be a delay in sending and receiving messages." https://support.signal.org/hc/en-us/articles/360007062172-Signal-Permissions#ios_permissions https://support.signal.org/hc/en-us/articles/360007062172-Si...
  - obituary_latte 7y ago
    That doesn’t mean encryption won’t work, just that you may not get instant notification of messages.
    - auslander 7y ago
      Yes, but I did not mention security. I commented on "I don’t think Signal uses it". I should've quoted it.
    - bertman 7y ago
      I wouldn't be so sure about that: https://twitter.com/moxie/status/1158852855291269120 https://twitter.com/moxie/status/1158852855291269120
      - dep_b 7y ago
        Would be interesting to hear his opinion on this. It's awesome anyway that all of the source is just in the open. I often use it as a sanity check for my own code when I'm dealing with messaging and VoIP.
      - vermilingua 7y ago
        You can test it yourself, by turning off background permissions. You will still receive messages. Background processing simply allows it to have the message ready for you by the time you open the app.
- makomk 7y ago
  The current Apple VoIP APIs don't actually let apps run in the background all the time anyway. What they provide is a way to instantly remotely wake up an app, let it connect to your server in the background, do some local processing, and then create and display a notification. This is exactly what end-to-end encrypted messaging needs, but Apple is killing off the ability to use the VoIP APIs in this way in iOS 13. Signal uses the exact same PushKit VoIP API that Facebook does, by the way - check PushRegistrationManager.swift in their source. I'm not sure if they use it for text chat as well as voice, but I assume so since there's no references to the newer API they could use in their code and they still support iOS 9 which doesn't have it (as do Facebook Messenger and WhatsApp). Edit: I think it's safe to say that Signal does this, given that Moxie Marlinspike isn't aware of any other way to do it: https://twitter.com/moxie/status/1158852855291269120 https://twitter.com/moxie/status/1158852855291269120 (Well, they don't intentionally let apps run all the time in the background. They're quite lax about how long apps can run for in the the background after being woken up in order to support voice calls, but that's not the feature messaging apps need from them.)
dan-robertson 7y ago
It wasn’t clear to me what that sentence meant. My best guess was that maybe WhatsApp needs to do background work to decrypt messages for notifications. Before you’ve unlocked a phone (to allow WhatsApp to access its keys), notifications just show up as “you got an encrypted message” and can’t show what the message is. Perhaps that would happen to all messages after this change. But then again it seems that apple would want to ensure that there’s still a good way to do end-to-end encryption, so I would guess there would be a workaround.

EGreg 7y ago

Doesn’t he mention explicitly in the video that you can use standard notifications and decrypt the payload before showing them? How exactly do you deliver notifications in Android? Can background apps simply listen on an open websocket or something?? What exactly is your technique on android

eridius 7y ago
I haven't watched the video, but Apple has a notifications API specifically for encrypted messaging apps to receive encrypted notifications and run a notification appex that decrypts the notification payload prior to showing the notification to the user.

fourthark 7y ago

It wasn't clear why they are using VoIP for WhatsApp. Sounded like it was because it allowed more background processing? I doubt they would ban end to end crypto, but you are right, it is more of a locked down system. Edit: keep reading. People explain this nicely below.

dep_b 7y ago

Not being able to lurk in the background does not have anything to do with security. I don’t think Signal uses it and they’re generally considered secure. You can check out their source.

auslander 7y ago
Signal docs say it needs Background permission : "Without this, there may be a delay in sending and receiving messages." https://support.signal.org/hc/en-us/articles/360007062172-Signal-Permissions#ios_permissions https://support.signal.org/hc/en-us/articles/360007062172-Si...
- obituary_latte 7y ago
  That doesn’t mean encryption won’t work, just that you may not get instant notification of messages.
  - auslander 7y ago
    Yes, but I did not mention security. I commented on "I don’t think Signal uses it". I should've quoted it.
  - bertman 7y ago
    I wouldn't be so sure about that: https://twitter.com/moxie/status/1158852855291269120 https://twitter.com/moxie/status/1158852855291269120
    - dep_b 7y ago
      Would be interesting to hear his opinion on this. It's awesome anyway that all of the source is just in the open. I often use it as a sanity check for my own code when I'm dealing with messaging and VoIP.
    - vermilingua 7y ago
      You can test it yourself, by turning off background permissions. You will still receive messages. Background processing simply allows it to have the message ready for you by the time you open the app.
makomk 7y ago
The current Apple VoIP APIs don't actually let apps run in the background all the time anyway. What they provide is a way to instantly remotely wake up an app, let it connect to your server in the background, do some local processing, and then create and display a notification. This is exactly what end-to-end encrypted messaging needs, but Apple is killing off the ability to use the VoIP APIs in this way in iOS 13. Signal uses the exact same PushKit VoIP API that Facebook does, by the way - check PushRegistrationManager.swift in their source. I'm not sure if they use it for text chat as well as voice, but I assume so since there's no references to the newer API they could use in their code and they still support iOS 9 which doesn't have it (as do Facebook Messenger and WhatsApp). Edit: I think it's safe to say that Signal does this, given that Moxie Marlinspike isn't aware of any other way to do it: https://twitter.com/moxie/status/1158852855291269120 https://twitter.com/moxie/status/1158852855291269120 (Well, they don't intentionally let apps run all the time in the background. They're quite lax about how long apps can run for in the the background after being woken up in order to support voice calls, but that's not the feature messaging apps need from them.)

dan-robertson 7y ago

It wasn’t clear to me what that sentence meant. My best guess was that maybe WhatsApp needs to do background work to decrypt messages for notifications. Before you’ve unlocked a phone (to allow WhatsApp to access its keys), notifications just show up as “you got an encrypted message” and can’t show what the message is. Perhaps that would happen to all messages after this change. But then again it seems that apple would want to ensure that there’s still a good way to do end-to-end encryption, so I would guess there would be a workaround.