Encrypt session cache when device is soft-locked

trezor / trezor-firmware

:lock: Trezor Firmware Monorepo

https://trezor.io

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Encrypt session cache when device is soft-locked #957

Open matejcik opened 4 years ago

matejcik commented 4 years ago

Soft-locked devices lock the storage, so that PIN is required to access private data.

However, derived seeds with passphrase applied are kept in RAM, so the soft-lock doesn't offer strong protection.

Secrets should also be encrypted in RAM when the device is locked.

tsusanka commented 4 years ago

We should also revisit that cache.py is the only place where the caching occurs (not in trezor-crypto etc.). For example that we do not cache nodes anywhere else.

fresheneesz commented 3 years ago

I came here to say this. Wouldn't this solve the infamous trezor vulnerability? Well.. actually thinking about it, a 4 number pin is probably brute forceable. So if ram could be extracted, I suppose maybe encrypting with the pin wouldn't help much.