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WhatsApp Blocking Encrypted Calls to All Saudi Numbers

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Re: WhatsApp Blocking Encrypted Calls to All Saudi Numbers

#61

Post by pfg »

stefs wrote: post #60
moxie wrote: post #50

Earlier quoted context omitted.

The author is incorrect. While Signal Protocol is used to communicate an SRTP master secret and a session id, the clients still need to do an ICE handshake in order to establish communication with each other before the responder can even ring. It is very straightforward for SA to block that traffic, and it is established fact that they do. It seems as if WhatsApp is short circuiting this frustrating series of timeout…

so this does affect foreign users using saudi telcos (roaming/wireless)? how about not blanket-blocking by country code, but by country-ip lookup?

Seems like a lot of effort for an edge case. Now you've added a dependency on some network service you need to access (and from WhatsApp's POV: maintain) before placing outgoing calls. If you use GPS instead, you're dependent on having the location permission (which is not needed to run WhatsApp in general), and you're draining everyone's battery and adding latency to get a sufficiently accurate location lock. Doesn't seem like it would be worth the trouble to me.

Re: WhatsApp Blocking Encrypted Calls to All Saudi Numbers

#62

Post by zeveb »

Tying an online messaging app to a phone number is fundamentally silly (attn Signal developers). Having phone numbers as one search item among many makes a lot of sense, but mandating a 1:1 relationship between phone numbers and app identities is like mandating a 1:1 relationship between horse stalls and automobiles.

Re: WhatsApp Blocking Encrypted Calls to All Saudi Numbers

#63

Post by tedunangst »

pmarreck wrote: post #57
subliminalpanda wrote: post #55

Earlier quoted context omitted.

The telco doesn't have much of a choice, as the rules are administered by the TRA (telecommunications regulatory authority), and by proxy, state security. No one that worked there wanted to do it, but refusing to do so would be reason to have them dismissed from their jobs. Many employees are expats; leaving their jobs would mean a loss of their residence and thus deportation. Such is life in a police state.

I correct myself, then: Your police state sucks. > but refusing to do so would be reason to have them dismissed from their jobs. I've quit jobs on principle before. The key is to have a nest egg. > Many employees are expats; leaving their jobs would mean a loss of their residence and thus deportation. Could they find another job?

Even better solution: All the WhatsApp users in Saudi Arabia should move to another country.

Re: WhatsApp Blocking Encrypted Calls to All Saudi Numbers

#64

Post by pfg »

zeveb wrote: post #62

Tying an online messaging app to a phone number is fundamentally silly (attn Signal developers). Having phone numbers as one search item among many makes a lot of sense, but mandating a 1:1 relationship between phone numbers and app identities is like mandating a 1:1 relationship between horse stalls and automobiles.

It makes a lot of sense for mobile messaging apps, though, and that's what both Signal and WhatsApp are. Phone number == username is an implementation detail of Signal (the app) and WhatsApp and not something the protocol dictates. Other implementations could easily handle things differently.

Re: WhatsApp Blocking Encrypted Calls to All Saudi Numbers

#65

Post by amluto »

Canada wrote: post #42
eridius wrote: post #40

Earlier quoted context omitted.

According to Wikipedia, ZRTP use a specific encryption protocol (SRTP). Surely that means that calls made using Signal can't be using ZRTP.

ZRTP is a key agreement protocol. It sets the key for SRTP, which is ultimately responsible for securing the RTP payload. SRTP keys can also be set by the signaling server, but then the encryption is not end to end. There's another protocol called SDP to handle this Signal does use ZRTP. It just doesn't use SIP. ZRTP is currently the best choice for voice.

> ZRTP is currently the best choice for voice.

I beg to differ. ZRTP is currently the best choice for voice when the caller and callee share no key material to begin with. In the context of Signal-the-app, the caller and callee often do share key material, but the protocol (to the best of my knowledge) doesn't bother to use that key material to authenticate the voice channel. This means that two users with the ability to securely text-message each other can still have their voice calls tapped if they fail to validate the short code each time.

The same omission also means that you cannot confirm that you have real end-to-end encryption by making a voice call and comparing the short authentication string on the screen.

I don't know whether Signal-the-protocol in WhatsApp is better designed, but calling ZRTP a good choice is ignoring the fact that current uses are not well thought out.

Re: WhatsApp Blocking Encrypted Calls to All Saudi Numbers

#66

Post by zeroxfe »

spacefight wrote: post #43

This case is a brilliant reminder to anyone working in deep packet inspection/blocking/filtering tech that your work negatively affects the safety of millions of people in such countries at once.

This is a ridiculous statement. You do know that this stuff actually enables safety, right?

Re: WhatsApp Blocking Encrypted Calls to All Saudi Numbers

#67

Post by subliminalpanda »

stefs wrote: post #60
moxie wrote: post #50

Earlier quoted context omitted.

The author is incorrect. While Signal Protocol is used to communicate an SRTP master secret and a session id, the clients still need to do an ICE handshake in order to establish communication with each other before the responder can even ring. It is very straightforward for SA to block that traffic, and it is established fact that they do. It seems as if WhatsApp is short circuiting this frustrating series of timeout…

so this does affect foreign users using saudi telcos (roaming/wireless)? how about not blanket-blocking by country code, but by country-ip lookup?

I've never been to Saudi Arabia, but in the UAE and Oman if you were to receive a WhatsApp call using a foreign number from a free country, lets say France, the handshake for the call would still be dropped with the attempted call failing.

On iOS, you would get an error saying "Call couldn't connect. X's mobile carrier or WiFi doesn't support WhatsApp calls".

Re: WhatsApp Blocking Encrypted Calls to All Saudi Numbers

#68

Post by jlgaddis »

pfg wrote: post #61
stefs wrote: post #60

Earlier quoted context omitted.

so this does affect foreign users using saudi telcos (roaming/wireless)? how about not blanket-blocking by country code, but by country-ip lookup?

Seems like a lot of effort for an edge case. Now you've added a dependency on some network service you need to access (and from WhatsApp's POV: maintain) before placing outgoing calls. If you use GPS instead, you're dependent on having the location permission (which is not needed to run WhatsApp in general), and you're draining everyone's battery and adding latency to get a sufficiently accurate location lock. Doesn'…

There would also be a number of people complaining loudly, demanding to know "why does WhatsApp look up my exact location [using the GPS] at the precise time I make a call!?".

Good luck convincing them that the location is not being logged permanently by WhatsApp servers -- or even sent to them in the first place.

Re: WhatsApp Blocking Encrypted Calls to All Saudi Numbers

#69

Post by ZainRiz »

littletimmy wrote: post #44
EdSharkey wrote: post #11

Thank you, WhatsApp! Oppressive governments, especially ones that have lots of resources to torment their citizens, should not get to play with our toys.

Saudi Arabia is one of the main US allies in the region. Millions of tax dollars go towards securing the Saudi regime every year through American military bases in the country.

Send tax dollars to dictators who execute people that ask for elections in order to support...democracy?

Re: WhatsApp Blocking Encrypted Calls to All Saudi Numbers

#70

Post by walrus01 »

eridius wrote: post #14
united893 wrote: post #3

They're simply providing a better user experience. The Saudis blocked encrypted calls, and users would have wait staring at frustrating repeated timeouts and long 'connecting' hangs. Therefore Whatsapp simply said OK, let's just improve the users experience by giving them an immediate error informing them.

The gist explicitly claims that's not possible. Specifically, it claims that there's no way for the Saudi teleco to distinguish encrypted phone calls from encrypted messages, and since you can send encrypted messages to Saudi users, there's no technical reason why you can't also call them. The implication is that if WhatsApp did allow the calls, the Saudi telecos might block both calls and messages (since they can't…

DPI can most definitely distinguish encrypted phone calls and traffic patterns. It's a lot more kbps of flow than messages.
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