1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73
//! HMAC-based Hierarchical Key Derivation: deterministically derive a //! hierarchy of symmetric keys from initial keying material through //! repeated applications of the Hash-based Message Authentication Code //! (HMAC) construction. //! //! This library implements a fully symmetric construction inspired by //! [BIP-0032: Hierarchical Deterministic Wallets][bip32]. //! //! # Usage //! //! To derive a key using HKD32, you'll need the following: //! //! - `hkd32::KeyMaterial`: a 32-byte (256-bit) uniformly random value //! - `hkd32::Path` or `hkd32::PathBuf`: path to the child key //! //! Derivation paths can be raw bytestrings but also support a Unix path-like //! syntax which can be parsed using the `String::parse` method: //! //! ```rust //! let path = "/foo/bar/baz".parse::<hkd32::PathBuf>().unwrap(); //! ``` //! //! # Example //! //! ```rust //! // Parent key //! let input_key_material = hkd32::KeyMaterial::random(); //! //! // Path to the child key //! let derivation_path = "/foo/bar/baz".parse::<hkd32::PathBuf>().unwrap(); //! //! // Derive subkey from the parent key. Call `as_bytes()` on this to obtain //! // a byte slice containing the derived key. //! let output_key_material = input_key_material.derive_subkey(derivation_path); //! ``` //! //! [bip32]: https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki #![no_std] #![deny( missing_docs, rust_2018_idioms, unused_lifetimes, unused_qualifications )] #![doc(html_root_url = "https://docs.rs/hkd32/0.3.1")] #[cfg(feature = "alloc")] #[cfg_attr(any(feature = "bip39", test), macro_use)] extern crate alloc; mod key_material; #[cfg(feature = "mnemonic")] pub mod mnemonic; mod path; #[cfg(feature = "alloc")] mod pathbuf; #[cfg(feature = "alloc")] pub use self::pathbuf::PathBuf; pub use self::{key_material::*, path::*}; /// Delimiter used for strings containing paths pub const DELIMITER: char = '/'; /// Size of input key material and derived keys. /// /// Note: the name HKD32 is both a play on this size and "BIP32". pub const KEY_SIZE: usize = 32; /// Opaque error type #[derive(Copy, Clone, Debug)] pub struct Error;