Soenneker.Hashing.Blake3 4.0.25

Soenneker.Hashing.Blake3

A high-performance .NET library for BLAKE3 hashing and constant-time verification. Pure C# with optional SIMD acceleration (AVX2 on x64, NEON on ARM).

Features

• BLAKE3 — 256-bit cryptographic hash; fast, secure, and specified in the official BLAKE3 spec.
• Zero dependencies — only the .NET runtime; no native or third-party packages.
• SIMD — uses AVX2 (x64) and NEON (ARM) when available for faster chunk hashing.
• Parallel hashing — HashParallel for large inputs; multi-threaded with batched SIMD where applicable.
• Span/Memory-friendly — hashing from byte[], ReadOnlySpan<byte>, ReadOnlyMemory<byte>, and in-place digest writing.
• Strings — hash UTF-8 strings and get hex output via Hash(string) and HashToString(string).
• Constant-time verification — Verify uses CryptographicOperations.FixedTimeEquals for digest comparison.
• Blake3Util — optional DI-registered utility for file and directory hashing (hash single files, whole directories, or an aggregate hash of a directory).

Installation

dotnet add package Soenneker.Hashing.Blake3

Quick Start

using Soenneker.Hashing.Blake3;

// Hash bytes → 32-byte digest
byte[] data = System.Text.Encoding.UTF8.GetBytes("hello world");
byte[] hash = Blake3Hasher.Hash(data);

// Hash string (UTF-8) → hex
string hex = Blake3Hasher.HashToString("hello world");
// e.g. "d74981efa70a0c0b14d123f472c6e570..."

// Verify digest (constant-time)
bool ok = Blake3Hasher.Verify(data, hash);

Usage

Hashing

Single-chunk and multi-chunk inputs use a scalar path; no extra allocations for the common case.

Parallel hashing (large inputs)

For large buffers, use the parallel API to spread work across cores and use SIMD batches where supported:

Parallelism kicks in when the input is large enough to form multiple chunks (e.g. > 4 KiB). For smaller inputs, the regular Hash methods are usually faster.

Blake3Util (file and directory hashing)

For file-based workflows, register Blake3Util (e.g. via Blake3UtilRegistrar) and inject IBlake3Util. It can hash individual files, entire directories, or produce a single aggregate hash for a directory (useful for integrity checks of a folder’s contents).

All methods are async and accept an optional CancellationToken. Files that cannot be read (e.g. access denied) are skipped when hashing directories.

Verification

All Verify overloads compare the computed BLAKE3 digest to an expected value in constant time (via CryptographicOperations.FixedTimeEquals). The expected digest must be 32 bytes (or 64 hex characters where applicable).

Output

• Digest length is 32 bytes (256 bits), as per BLAKE3.
• Hex strings from HashToString are 64 lowercase hex characters.