Class ChaCha20

Class for ChaCha20 encryption / decryption

Inheritance

object

ChaCha20

Implements

IDisposable

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: CSChaCha20

Assembly: .dll

Syntax

public sealed class ChaCha20 : IDisposable

Constructors

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ChaCha20(byte[], byte[], uint)

Set up a new ChaCha20 state. The lengths of the given parameters are checked before encryption happens.

Declaration

public ChaCha20(byte[] key, byte[] nonce, uint counter)

Parameters

Type	Name	Description
byte[]	key	A 32-byte (256-bit) key, treated as a concatenation of eight 32-bit little-endian integers
byte[]	nonce	A 12-byte (96-bit) nonce, treated as a concatenation of three 32-bit little-endian integers
uint	counter	A 4-byte (32-bit) block counter, treated as a 32-bit little-endian integer

Remarks

See ChaCha20 Spec Section 2.4 for a detailed description of the inputs.

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ChaCha20(ReadOnlySpan<byte>, ReadOnlySpan<byte>, uint)

Set up a new ChaCha20 state. The lengths of the given parameters are checked before encryption happens.

Declaration

public ChaCha20(ReadOnlySpan<byte> key, ReadOnlySpan<byte> nonce, uint counter)

Parameters

Type	Name	Description
ReadOnlySpan<byte>	key	A 32-byte (256-bit) key, treated as a concatenation of eight 32-bit little-endian integers
ReadOnlySpan<byte>	nonce	A 12-byte (96-bit) nonce, treated as a concatenation of three 32-bit little-endian integers
uint	counter	A 4-byte (32-bit) block counter, treated as a 32-bit little-endian unsigned integer

Remarks

See ChaCha20 Spec Section 2.4 for a detailed description of the inputs.

Fields

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allowedKeyLength

Only allowed key lenght in bytes

Declaration

public const int allowedKeyLength = 32

Field Value

Type	Description
int

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allowedNonceLength

Only allowed nonce lenght in bytes

Declaration

public const int allowedNonceLength = 12

Field Value

Type	Description
int

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processBytesAtTime

How many bytes are processed per loop

Declaration

public const int processBytesAtTime = 64

Field Value

Type	Description
int

Properties

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State

The ChaCha20 state (aka "context"). Read-Only.

Declaration

public uint[] State { get; }

Property Value

Type	Description
uint[]

Methods

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DecryptBytes(byte[], SimdMode)

Decrypt arbitrary-length byte array (input), writing the resulting byte array that is allocated by method.

Declaration

public byte[] DecryptBytes(byte[] input, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
byte[]	input	Input byte array
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Returns

Type	Description
byte[]	Byte array that contains decrypted bytes

Remarks

Since this is symmetric operation, it doesn't really matter if you use Encrypt or Decrypt method

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DecryptBytes(byte[], byte[], SimdMode)

Decrypt arbitrary-length byte array (input), writing the resulting byte array to preallocated output buffer.

Declaration

public void DecryptBytes(byte[] output, byte[] input, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
byte[]	output	Output byte array, must have enough bytes
byte[]	input	Input byte array
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Remarks

Since this is symmetric operation, it doesn't really matter if you use Encrypt or Decrypt method

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DecryptBytes(byte[], byte[], int, SimdMode)

Decrypt arbitrary-length byte array (input), writing the resulting byte array to the output buffer.

Declaration

public void DecryptBytes(byte[] output, byte[] input, int numBytes, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
byte[]	output	Output byte array
byte[]	input	Input byte array
int	numBytes	Number of bytes to decrypt
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Remarks

Since this is symmetric operation, it doesn't really matter if you use Encrypt or Decrypt method

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DecryptBytes(byte[], int, SimdMode)

Decrypt arbitrary-length byte array (input), writing the resulting byte array that is allocated by method.

Declaration

public byte[] DecryptBytes(byte[] input, int numBytes, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
byte[]	input	Input byte array
int	numBytes	Number of bytes to encrypt
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Returns

Type	Description
byte[]	Byte array that contains decrypted bytes

Remarks

Since this is symmetric operation, it doesn't really matter if you use Encrypt or Decrypt method

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DecryptStream(Stream, Stream, int, SimdMode)

Decrypt arbitrary-length byte stream (input), writing the resulting bytes to another stream (output)

Declaration

public void DecryptStream(Stream output, Stream input, int howManyBytesToProcessAtTime = 1024, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
Stream	output	Output stream
Stream	input	Input stream
int	howManyBytesToProcessAtTime	How many bytes to read and write at time, default is 1024
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

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DecryptStreamAsync(Stream, Stream, int, SimdMode)

Async decrypt arbitrary-length byte stream (input), writing the resulting bytes to another stream (output)

Declaration

public Task DecryptStreamAsync(Stream output, Stream input, int howManyBytesToProcessAtTime = 1024, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
Stream	output	Output stream
Stream	input	Input stream
int	howManyBytesToProcessAtTime	How many bytes to read and write at time, default is 1024
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Returns

Type	Description
Task

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DecryptUTF8ByteArray(byte[], SimdMode)

Decrypt UTF8 byte array to string.

Declaration

public string DecryptUTF8ByteArray(byte[] input, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
byte[]	input	Byte array
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Returns

Type	Description
string	Byte array that contains encrypted bytes

Remarks

Here you can NOT swap encrypt and decrypt methods, because of bytes-string transform

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Dispose()

Clear and dispose of the internal state. Also request the GC not to call the finalizer, because all cleanup has been taken care of.

Declaration

public void Dispose()

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EncryptBytes(byte[], SimdMode)

Encrypt arbitrary-length byte array (input), writing the resulting byte array that is allocated by method.

Declaration

public byte[] EncryptBytes(byte[] input, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
byte[]	input	Input byte array
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Returns

Type	Description
byte[]	Byte array that contains encrypted bytes

Remarks

Since this is symmetric operation, it doesn't really matter if you use Encrypt or Decrypt method

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EncryptBytes(byte[], byte[], SimdMode)

Encrypt arbitrary-length byte array (input), writing the resulting byte array to preallocated output buffer.

Declaration

public void EncryptBytes(byte[] output, byte[] input, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
byte[]	output	Output byte array, must have enough bytes
byte[]	input	Input byte array
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Remarks

Since this is symmetric operation, it doesn't really matter if you use Encrypt or Decrypt method

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EncryptBytes(byte[], byte[], int, SimdMode)

Encrypt arbitrary-length byte array (input), writing the resulting byte array to preallocated output buffer.

Declaration

public void EncryptBytes(byte[] output, byte[] input, int numBytes, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
byte[]	output	Output byte array, must have enough bytes
byte[]	input	Input byte array
int	numBytes	Number of bytes to encrypt
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Remarks

Since this is symmetric operation, it doesn't really matter if you use Encrypt or Decrypt method

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EncryptBytes(byte[], int, SimdMode)

Encrypt arbitrary-length byte array (input), writing the resulting byte array that is allocated by method.

Declaration

public byte[] EncryptBytes(byte[] input, int numBytes, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
byte[]	input	Input byte array
int	numBytes	Number of bytes to encrypt
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Returns

Type	Description
byte[]	Byte array that contains encrypted bytes

Remarks

Since this is symmetric operation, it doesn't really matter if you use Encrypt or Decrypt method

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EncryptStream(Stream, Stream, int, SimdMode)

Encrypt arbitrary-length byte stream (input), writing the resulting bytes to another stream (output)

Declaration

public void EncryptStream(Stream output, Stream input, int howManyBytesToProcessAtTime = 1024, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
Stream	output	Output stream
Stream	input	Input stream
int	howManyBytesToProcessAtTime	How many bytes to read and write at time, default is 1024
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

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EncryptStreamAsync(Stream, Stream, int, SimdMode)

Async encrypt arbitrary-length byte stream (input), writing the resulting bytes to another stream (output)

Declaration

public Task EncryptStreamAsync(Stream output, Stream input, int howManyBytesToProcessAtTime = 1024, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
Stream	output	Output stream
Stream	input	Input stream
int	howManyBytesToProcessAtTime	How many bytes to read and write at time, default is 1024
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Returns

Type	Description
Task

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EncryptString(string, SimdMode)

Encrypt string as UTF8 byte array, returns byte array that is allocated by method.

Declaration

public byte[] EncryptString(string input, SimdMode simdMode = SimdMode.AutoDetect)

Parameters

Type	Name	Description
string	input	Input string
SimdMode	simdMode	Chosen SIMD mode (default is auto-detect)

Returns

Type	Description
byte[]	Byte array that contains encrypted bytes

Remarks

Here you can NOT swap encrypt and decrypt methods, because of bytes-string transform

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~ChaCha20()

Clear and dispose of the internal state. The finalizer is only called if Dispose() was never called on this cipher.

Declaration

protected ~ChaCha20()

Implements

IDisposable