Table of Contents

Class HashAlgorithm

Namespace
CryptoHives.Foundation.Security.Cryptography.Hash
Assembly
CryptoHives.Foundation.Security.Cryptography.dll

Base class for the CryptoHives hash algorithm implementations.

public abstract class HashAlgorithm : HashAlgorithm, ICryptoTransform, IDisposable, IResettable
Inheritance
HashAlgorithm
Implements
Derived
Inherited Members

Remarks

This class extends HashAlgorithm to provide a common base for all CryptoHives hash implementations. It ensures consistent behavior and provides helper methods for derived implementations.

All derived classes implement hash algorithms without OS or hardware dependencies, providing deterministic behavior across all platforms.

Constructors

HashAlgorithm()

Initializes a new instance of the HashAlgorithm class.

protected HashAlgorithm()

Properties

AlgorithmName

Gets the name of the hash algorithm.

public abstract string AlgorithmName { get; }

Property Value

string

BlockSize

Gets the block size in bytes used by the hash algorithm.

public abstract int BlockSize { get; }

Property Value

int

Methods

AppendData(in ReadOnlySequence<byte>)

Appends all segments of source to the data already processed in the hash algorithm.

public void AppendData(in ReadOnlySequence<byte> source)

Parameters

source ReadOnlySequence<byte>

The (possibly multi-segment) input sequence to append to the hash computation.

Remarks

Use this overload when data arrives from System.IO.Pipelines or any other source that provides a ReadOnlySequence<T>. Each segment is fed directly into the algorithm without copying the data into a contiguous buffer.

Call TryGetHashAndReset(Span<byte>, out int) after all data has been appended to retrieve the final hash value and reset the algorithm for reuse.

AppendData(ReadOnlySpan<byte>)

Appends the specified data to the data already processed in the hash algorithm.

public void AppendData(ReadOnlySpan<byte> source)

Parameters

source ReadOnlySpan<byte>

The input to append to the hash computation.

Remarks

This is a zero-allocation alternative to TransformBlock(byte[], int, int, byte[], int) for incremental hashing with span-based buffers.

Call TryGetHashAndReset(Span<byte>, out int) after all data has been appended to retrieve the final hash value and reset the algorithm for reuse. 

using var sha256 = SHA256.Create();
sha256.AppendData(chunk1);
sha256.AppendData(chunk2);
Span<byte> hash = stackalloc byte[32];
sha256.TryGetHashAndReset(hash, out _);

ClearBuffer(Span<byte>)

Clears sensitive data from a span.

protected static void ClearBuffer(Span<byte> data)

Parameters

data Span<byte>

The data to clear.

Create(string)

Creates a new instance of the specified hash algorithm.

public static HashAlgorithm Create(string hashName)

Parameters

hashName string

The name of the hash algorithm to create.

Returns

HashAlgorithm

A new hash algorithm instance.

Exceptions

ArgumentException

The specified algorithm name is unknown.

PlatformNotSupportedException

The specified algorithm is not supported.

Create(string, bool)

Creates a new instance of the specified hash algorithm. Optionally uses the OS version (mostly faster) if available.

public static HashAlgorithm Create(string hashName, bool osVersion = false)

Parameters

hashName string

The name of the hash algorithm to create.

osVersion bool

Set to true to instantiate the OS version of the algorithm, if available.

Returns

HashAlgorithm

A new hash algorithm instance.

Exceptions

ArgumentException

The specified algorithm name is unknown.

PlatformNotSupportedException

The specified algorithm is not supported.

HashCore(byte[], int, int)

When overridden in a derived class, routes data written to the object into the hash algorithm for computing the hash.

protected override sealed void HashCore(byte[] array, int ibStart, int cbSize)

Parameters

array byte[]

The input to compute the hash code for.

ibStart int

The offset into the byte array from which to begin using data.

cbSize int

The number of bytes in the byte array to use as data.

Remarks

Overridden to route to the HashCore(ReadOnlySpan{byte} method. Implementations should override that method instead.

HashCore(ReadOnlySpan<byte>)

When overridden in a derived class, routes data written to the object into the hash algorithm for computing the hash.

protected abstract void HashCore(ReadOnlySpan<byte> source)

Parameters

source ReadOnlySpan<byte>

The input to compute the hash code for.

HashFinal()

When overridden in a derived class, finalizes the hash computation after the last data is processed by the cryptographic stream object.

protected override sealed byte[] HashFinal()

Returns

byte[]

The computed hash code.

TryComputeHash(ReadOnlySpan<byte>, Span<byte>, out int)

Attempts to compute the hash value for the specified read-only byte span and writes the result into the provided destination span.

public bool TryComputeHash(ReadOnlySpan<byte> source, Span<byte> destination, out int bytesWritten)

Parameters

source ReadOnlySpan<byte>

The input to compute the hash code for.

destination Span<byte>

The buffer to receive the hash value.

bytesWritten int

When this method returns, the total number of bytes written into destination.

Returns

bool

true if destination is long enough to receive the hash value; otherwise, false.

Remarks

The algorithm is automatically reset after a successful computation, allowing the instance to be reused for subsequent AppendData(ReadOnlySpan<byte>) calls or another TryComputeHash(ReadOnlySpan<byte>, Span<byte>, out int) without calling Initialize() first.

TryGetHashAndReset(Span<byte>, out int)

Finalizes the hash computation, writes the result into the provided buffer, and resets the algorithm for reuse.

public bool TryGetHashAndReset(Span<byte> destination, out int bytesWritten)

Parameters

destination Span<byte>

The buffer to receive the hash value.

bytesWritten int

When this method returns, the total number of bytes written into destination.

Returns

bool

true if destination is long enough to receive the hash value; otherwise, false.

Remarks

This is a zero-allocation alternative to reading the Hash property after TransformFinalBlock(byte[], int, int).

The algorithm is automatically reset after a successful call, allowing the instance to be reused for a new computation without calling Initialize().

Exceptions

ObjectDisposedException

The instance has been disposed.

TryHashFinal(Span<byte>, out int)

When overridden in a derived class, finalizes the hash computation and writes the result into the provided buffer.

protected abstract bool TryHashFinal(Span<byte> destination, out int bytesWritten)

Parameters

destination Span<byte>

The target buffer to write the hash to.

bytesWritten int

The number of bytes written into the buffer.

Returns

bool

true if the destination buffer was large enough; otherwise false.

TryReset()

Resets this instance to its initial state so it can be returned to an object pool for reuse.

public virtual bool TryReset()

Returns

bool

true if the instance was reset and may be returned to the pool; false if it must instead be disposed and discarded (see remarks).

Remarks

This method implements IResettable from Microsoft.Extensions.ObjectPool, enabling any CryptoHives hash algorithm to be used with DefaultObjectPool<T> without a custom policy.

Overridden by algorithms that can carry caller-supplied secret material (e.g. a keyed BLAKE3 instance): those return false so the pool's policy disposes the instance — erasing the secret — instead of recycling it for an unrelated caller.

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