scrypt-rs

Minimal command-line tool for scrypt key derivation (RFC 7914).

Reads a passphrase from stdin, normalizes whitespace, derives a key using scrypt, and outputs the result in hex, base64, and/or BIP39 mnemonic format.

Credit to w3rs/kdftool which this tool is originally based on.

Installation

From source

cargo install --path .

From releases

Download a pre-built binary from the Releases page.

Usage

echo "my passphrase" | scrypt-rs [OPTIONS]

Options

Flag	Long	Default	Description
-S	--short		Output only the hex-encoded derived key
-s	--salt	""	Salt string
-L	--logn	19	log₂(N) — CPU/memory cost parameter
-r		8	Block size parameter
-p		2	Parallelization parameter
-l	--len	16	Derived key length in bytes

Examples

Short output (hex only):

echo "my secret passphrase" | scrypt-rs -S -s "my salt" -L 14 -r 8 -p 1 -l 32

Full output (shows all input parameters + hex, base64, and BIP39):

echo "my secret passphrase" | scrypt-rs -s "my salt" -L 14 -r 8 -p 1 -l 32

Example full output:

Input | Salt: "my salt"
Input | Normalized passphrase: "my secret passphrase"
Input | Scrypt parameters: cost factor 14 - blocksize 8 - parallelization 1 - key length in bytes 32
Output| Scrypt derived key in hexadecimal: <hex>
Output| Scrypt derived key in base64: <base64>
Output| Scrypt BIP39 words list representation: <24 words>

BIP39 output

BIP39 mnemonic generation requires the derived key length to be one of: 16, 20, 24, 28, or 32 bytes. Other lengths will show "Unable to generate words list".

Building

cargo build --release

Development

cargo fmt       # format code
cargo clippy    # lint
cargo test      # run all tests

License

GPL-3.0