Extend `KeyProvider` to accept arbitrary length pass-phrases

[felsweg-iota]

Description

KeyProvider currently supports only keys of a certain length. Prior implementation truncated the provided passphrases to a certain length. This features request shall extend KeyProvider to have two more construction functions, that

• create a KeyProvider with a passphrase of arbitrary length, which is truncated internally and shall have following signature with_passphrase_truncated<P>(passphrase : P) -> Result<Self, ClientError> where P : AsRef<[u8]> + Zeroize
• create a KeyProvider with a passphrase of arbitrary length, which is hashed with a cryptographically secure hash function and shall have the following signature with_passphrase_hashed<P,D>(passphrase : P, digest : D) -> Result<Self, ClientError> where P : AsRef<[u8]> + Zeroize, D: Digest
• create a KeyProvider with a passphrase of arbitrary length, which is hashed with blake2b function and shall have the following signature with_passphrase_hashed_blake2b<P,D>(passphrase : P) -> Result<Self, ClientError> where P : AsRef<[u8]> + Zeroize, D: Digest

Motivation

Passphrases should not be restricted in size, and Stronghold should make sure to enforce strong passphrase security by applying strong cryptographic functions.

Requirements

1. This feature only enhances the current KeyProvider behavior

Are you planning to do it yourself in a pull request?

Yes