101–110 of 199 posts
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> I don't care about their Intel SGX whatever because I don't want to have to trust their servers in the first place. Yeah: particularly given how Intel SGX gets broken every year :/... prime+probe, foreshadow, load value injection, plundervolt... Moxie's fetish for Intel SGX is extremely concerning.
SGX has simply just been shown to be incompatible with secure software and is impossible to justify. Signal can happily operate without the need for this sort of thing to begin with, but they keep insisting on weak solutions for no reason.
This is all well and good. But the forced/unsilenceable pin reminders seems a bit obtuse to me. https://support.signal.org/hc/en-us/articles/360007059792-Si... "Can I turn off these reminders? It is important to memorize your PIN, and the reminders cannot be disabled. We cannot recover your PIN if you forget it. You will see the reminders less frequently if you consistently enter your PIN correctly. The reminders wil…
I've been using Signal PINs for a long time to lock the app to my SIM card and unfortunately they are a real pain. This sounds exactly the same. First off the app is incessant about asking you to enter your PIN to prove you know it; this prompt is supposed to get less frequent and I suppose it does but is still way too frequent. Some of us are competent at storing secrets in a password manager and this is like a puni…
I've found that tapping next to the registration lock PIN prompt will dismiss it on Android. A "dismiss" button and a "don't ask me again, I won't lose this" checkmark would make much more sense to me.
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Basically, SGX: https://github.com/signalapp/SecureValueRecovery The enclave is hardened against Spectre and LVI with this (BOLT/LLVM based), and other techniques: https://github.com/signalapp/BOLT The last build step before signing is a verifier that checks that there are no missed mitigations, built using Intel Xed, to try to avoid potential missing mitigations due to an LLVM or BOLT bug.
I'm familiar with Signal's usage of enclaves. The case I'm wondering about is what happens if someone seized (or surreptitiously accessed) Signal's servers, ran the unmodified enclaves, but fed in different PIN requests to those enclaves in a brute-forcing attempt. What prevents that?
To do this securely made the whole thing quite difficult, because it means we can never persist anything outside the enclave, or an attacker could unpersist into 1000 unmodified enclaves (who would never know about each other) and get 1000*N guesses.
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Basically, SGX: https://github.com/signalapp/SecureValueRecovery The enclave is hardened against Spectre and LVI with this (BOLT/LLVM based), and other techniques: https://github.com/signalapp/BOLT The last build step before signing is a verifier that checks that there are no missed mitigations, built using Intel Xed, to try to avoid potential missing mitigations due to an LLVM or BOLT bug.
I'm familiar with Signal's usage of enclaves. The case I'm wondering about is what happens if someone seized (or surreptitiously accessed) Signal's servers, ran the unmodified enclaves, but fed in different PIN requests to those enclaves in a brute-forcing attempt. What prevents that?
Looking at the code quickly I see that nothing is documented and it's not clear what code gets executed there. So good luck understanding what they're doing. But it seems to be using Raft, probably to bring several HSMs to consensus on what's the state of the number of attempts. And it does seem to erase stuff if you reach some threshold of attempts: https://github.com/signalapp/SecureValueRecovery/blob/00d023...
My follow up question is: what prevents someone from destroying your account's backup key by entering wrong PINs for your account?
This is all well and good. But the forced/unsilenceable pin reminders seems a bit obtuse to me. https://support.signal.org/hc/en-us/articles/360007059792-Si... "Can I turn off these reminders? It is important to memorize your PIN, and the reminders cannot be disabled. We cannot recover your PIN if you forget it. You will see the reminders less frequently if you consistently enter your PIN correctly. The reminders wil…
How did they not learn from this when they tried it with the activation lock.
I'm extremely disappointed about how this Signal PIN rollout has been handled. Signal refused to let me view my received messages until I created a PIN. I filed a bug report about it [1]. I don't know if I was just caught in an A/B test or what because it hasn't happened to all of my Signal-using friends but it happened to me. I don't understand why it isn't just optional. They claim they want to protect my Signal da…
they probably got served with a secret order from the gov.
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What are they for?
Read the blog post, friend! They're for restoring your data to a new device.
They should explain what the pins is BEFORE they ask. What it looks like is you are going to be locked out of signal if you make a mistake. Not like the average signal user is watching the whisper systems blog.
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Read the blog post, friend! They're for restoring your data to a new device.
Still stupid, shouldn't they ask if I want that functionality? Not like it's going to be hard to brute force a user's PIN. They should explain what the pins is BEFORE they ask. What it looks like is you are going to be locked out of signal if you make a mistake. Not like the average signal user is watching the whisper systems blog.
I guess it depends on if you buy into SGX. Lots of people don't.
> Still stupid
Yeah, this isn't making anyone happy it seems. Still, they are a small organization and having configuration increases maintenance burden. As long as Signal keeps operating as non-commercial product, I will keep cutting them slack.