Pure Rust implementation of the hashing algorithms used by the Nix package manager. Based on Eelco Dolstra's PhD thesis The Purely Functional Software Deployment Model (2006) and the Nix C++ reference implementation. Can do Nix32 encoding and decoding using Nix's custom base-32 alphabet (digits + lowercase letters minus e, o, u, t) and provides various hash functions such as MD5, SHA-1, SHA-256, SHA-512 via the hash module. Hash compression is also possible, you may compress a 32-byte SHA-256 hash to 20 bytes via cyclic XOR. This is used for store path hashes.

Other features:

• SRI formatting - algo-base64 (W3C Subresource Integrity, used by nix hash to-sri)
• Store path construction - makeStorePath, makeOutputPath, makeFixedOutputPath as described in the thesis

use nix_hash::store_path::StoreDir;
use nix_hash::nix32::Nix32;
use nix_hash::hash::{hash_string, to_sri, HashAlgorithm};

// Compute a store path
let store = StoreDir::default(); // /nix/store
let path = store.make_store_path("output:out", "sha256:abc123", "hello-1.0");
assert!(path.ends_with("-hello-1.0"));

// Format a hash as SRI
let hash = hash_string(HashAlgorithm::Sha256, "hello");
let sri = to_sri(HashAlgorithm::Sha256, &hash);
assert_eq!(sri, "sha256-LPJNul+wow4m6DsqxbninhsWHlwfp0JecwQzYpOLmCQ=");