Rust¶

Rust implementation of the spec. Requires Rust ≥ 1.85. The only runtime dependencies are the audited RustCrypto crates aes and sha2.

Source of truth: rust/ on GitHub · full README

Install¶

cargo add dealcode

Minimal example¶

use dealcode::Dealcode;

let codec = Dealcode::new("0a1b...64-hex-chars-from-your-secret-manager")?;

codec.encode(0)?;        // "767a5b"   (6 hex chars)
codec.encode(1)?;        // "421163"   never collides with any other counter
codec.decode("421163")?; // 1

API surface¶

Item	Notes
`Dealcode::new(key)`	defaults; key is `impl Into<Key>`: `&str`, `String`, `&[u8]`, `Vec<u8>`, `[u8; N]`
`Dealcode::builder(key).alphabet(..).min_length(..).max_length(..).domain(..).build()`	invalid config → `Err(Error::Config)`
`codec.encode(n: u64) -> Result<String>`	`Err(Error::Range)` outside `[0, codec.capacity())`
`codec.decode(code) -> Result<u64>`	`Err(Error::InvalidCode)` for malformed input
`CyclingDealcode::builder(key)...length(..).build()` + `cycle_of(n)`	fixed-length cycling mode, SPEC §11 — see the configuration guide
Errors	`dealcode::Error` (`Config` / `Range` / `InvalidCode`), implements `std::error::Error`

A Dealcode instance is immutable and Send + Sync — share it in an Arc or a static. AES round keys and per-length FF1 parameters are precomputed at build time.

Tests¶

cd rust && cargo test && cargo clippy --all-targets -- -D warnings

Covers the official NIST FF1 sample vectors, every shared cross-language vector, behavioural cases, and doctests.