dcrypt_algorithms::xof

Module blake3

Source
Expand description

BLAKE3 extendable output function (XOF) implementation

This module provides a pure Rust implementation of the BLAKE3 cryptographic hash function in XOF (eXtendable Output Function) mode, allowing for arbitrary-length output generation.

§Overview

BLAKE3 is a cryptographic hash function that is:

  • Fast: Optimized for modern CPUs with SIMD instructions
  • Secure: Based on the well-analyzed ChaCha permutation
  • Versatile: Supports hashing, keyed hashing, and key derivation
  • Parallelizable: Can process multiple chunks simultaneously
  • Incremental: Supports streaming/incremental hashing

§Security Properties

  • Security Level: 256 bits (128-bit collision resistance)
  • Output Size: Variable (unlimited in XOF mode)
  • Key Size: 256 bits (32 bytes) for keyed variants

§Features

This implementation provides three modes of operation:

  1. Standard XOF: Variable-length output from input data
  2. Keyed XOF: HMAC-like keyed hashing with variable output
  3. Key Derivation: Derive keys from a context string and input data

§Implementation Notes

This implementation prioritizes correctness and security over performance:

  • Uses secure memory handling with SecretBuffer for sensitive data
  • Implements proper zeroization of sensitive values
  • Based directly on the BLAKE3 reference implementation
  • Does not include SIMD optimizations

§Example Usage

ⓘ
use dcrypt_algorithms::xof::{Blake3Xof, ExtendableOutputFunction};

// Standard hashing with variable output
let data = b"Hello, BLAKE3!";
let output = Blake3Xof::generate(data, 64)?; // 64 bytes output

// Incremental hashing
let mut xof = Blake3Xof::new();
xof.update(b"Hello, ")?;
xof.update(b"BLAKE3!")?;
let mut output = vec![0u8; 64];
xof.squeeze(&mut output)?;

// Keyed hashing
let key = b"this is a 32-byte key for BLAKE3";
let output = Blake3Xof::keyed_generate(key, data, 32)?;

// Key derivation
let context = b"MyApp v1.0.0 session key";
let output = Blake3Xof::derive_key(context, data, 32)?;

§References

Structs§

Blake3Xof
BLAKE3 extendable output function