Seedroller and keyderiver: cli tools to generate BIP39 seed words and derive BIP380 keys

Implementation
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1

In light of recent events I became interested in how to safely generate a strong random seed. The closest tool I found in rust is seedtool-cli-rust but it has a lot of dependencies I don’t recognize and I prefer building on the rust-bitcoin orgs crates.

I humbly submit my own cli tool seedroller for generating BIP39 seed words from dice rolls hashed with getrandom() system entropy. I also created a companion cli tool keyderiver that takes your seed words and derives BIP380 descriptor key expressions. Both are based on rust-bitcoin org rust crates and have minimal other dependencies. For all the fun details please checkout the bitcoin-key-tools repo.

Feedback is much appreciated, this is still early work and I’m happy to implement suggestions that improve these tools soundness and security.

2

This looks interesting. For people using dice because they want to avoid relying on a computer for randomness, would it make sense to offer a clearly labelled dice-only option as well?

That could make it easier for users to understand exactly what they are trusting and choose the approach they are comfortable with.

3

Thanks for taking a look. There is already a -r option that only takes dice roles, so it can give “reproducable” results, ie. same dice rolls after sha256 hash always give same seed words. I compare with the results from iancolman.io/bip39 in the known_answer_100_rolls_no_os_entropy unit test.