Secure keystore of lightning nodes / wallets

[renepickhardt]

In chapter two / getting started we currently write: The most common components of lightning wallet software include: A keystore that securely holds secrets, such as private keys.

I am not sure how secure the keystore currently is on LN nodes.

I believe in early days there was no way to encrypt wallet.dat and wallet.dat has been stolen leaked. in a same way for example in c-lightning we have hsm_secret that stores the private master key in plain binary format and the entire state is stored in plain text in a sql database. For state information it will be even more tricky to encrypt this as the state will / should change without user interaction. while hsm_secret could be encrypted the decrypted version would have to be in main memory and could be found with a full memory dump. there are not too many variables to check in a full mem copy.

I am not sure how comfortable I feel suggesting that lighting implementations have a secure keystore.

[renepickhardt]

c-lightning has at least https://github.com/ElementsProject/lightning/blob/master/tools/hsmtool.c that can be used to somewhat secure hsm_secret

[darosior]

c-lightning has at least https://github.com/ElementsProject/lightning/blob/master/tools/hsmtool.c that can be used to somewhat secure hsm_secret

C-lightning also support hsm_secret encryption, just start lightningd with --encrypted-hsm.

while hsm_secret could be encrypted the decrypted version would have to be in main memory and could be found with a full memory dump. there are not too many variables to check in a full mem copy.

The specific content of hsm_secret is read in non-swapable (mlocked) memory. However, most of the secrets are still stored in swapable memory as of today.