Class ChaCha20

Class that can be used for ChaCha20 encryption / decryption

Inheritance

System.Object

ChaCha20

Implements

System.IDisposable

Inherited Members

System.Object.ToString()

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

Namespace: CSChaCha20

Assembly: cs.temp.dll.dll

Syntax

public sealed class ChaCha20 : IDisposable

Constructors

ChaCha20(Byte[], Byte[], UInt32)

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
System.Byte[]	key	A 32-byte (256-bit) key, treated as a concatenation of eight 32-bit little-endian integers
System.Byte[]	nonce	A 12-byte (96-bit) nonce, treated as a concatenation of three 32-bit little-endian integers
System.UInt32	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.

Fields

allowedKeyLength

Only allowed key lenght in bytes

Declaration

public const int allowedKeyLength = 32

Field Value

Type	Description
System.Int32

allowedNonceLength

Only allowed nonce lenght in bytes

Declaration

public const int allowedNonceLength = 12

Field Value

Type	Description
System.Int32

processBytesAtTime

How many bytes are processed per loop

Declaration

public const int processBytesAtTime = 64

Field Value

Type	Description
System.Int32

Properties

State

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

Declaration

public uint[] State { get; }

Property Value

Type	Description
System.UInt32[]

Methods

DecryptBytes(Byte[])

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

Declaration

public byte[] DecryptBytes(byte[] input)

Parameters

Type	Name	Description
System.Byte[]	input	Input byte array

Returns

Type	Description
System.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

DecryptBytes(Byte[], Byte[])

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

Declaration

public void DecryptBytes(byte[] output, byte[] input)

Parameters

Type	Name	Description
System.Byte[]	output	Output byte array, must have enough bytes
System.Byte[]	input	Input byte array

Remarks

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

DecryptBytes(Byte[], Byte[], Int32)

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)

Parameters

Type	Name	Description
System.Byte[]	output	Output byte array
System.Byte[]	input	Input byte array
System.Int32	numBytes	Number of bytes to decrypt

Remarks

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

DecryptBytes(Byte[], Int32)

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

Declaration

public byte[] DecryptBytes(byte[] input, int numBytes)

Parameters

Type	Name	Description
System.Byte[]	input	Input byte array
System.Int32	numBytes	Number of bytes to encrypt

Returns

Type	Description
System.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

DecryptStream(Stream, Stream, Int32)

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)

Parameters

Type	Name	Description
System.IO.Stream	output	Output stream
System.IO.Stream	input	Input stream
System.Int32	howManyBytesToProcessAtTime	How many bytes to read and write at time, default is 1024

DecryptStreamAsync(Stream, Stream, Int32)

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)

Parameters

Type	Name	Description
System.IO.Stream	output	Output stream
System.IO.Stream	input	Input stream
System.Int32	howManyBytesToProcessAtTime	How many bytes to read and write at time, default is 1024

Returns

Type	Description
System.Threading.Tasks.Task

DecryptUTF8ByteArray(Byte[])

Decrypt UTF8 byte array to string.

Declaration

public string DecryptUTF8ByteArray(byte[] input)

Parameters

Type	Name	Description
System.Byte[]	input	Byte array

Returns

Type	Description
System.String	Byte array that contains encrypted bytes

Remarks

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

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()

EncryptBytes(Byte[])

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

Declaration

public byte[] EncryptBytes(byte[] input)

Parameters

Type	Name	Description
System.Byte[]	input	Input byte array

Returns

Type	Description
System.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

EncryptBytes(Byte[], Byte[])

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

Declaration

public void EncryptBytes(byte[] output, byte[] input)

Parameters

Type	Name	Description
System.Byte[]	output	Output byte array, must have enough bytes
System.Byte[]	input	Input byte array

Remarks

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

EncryptBytes(Byte[], Byte[], Int32)

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)

Parameters

Type	Name	Description
System.Byte[]	output	Output byte array, must have enough bytes
System.Byte[]	input	Input byte array
System.Int32	numBytes	Number of bytes to encrypt

Remarks

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

EncryptBytes(Byte[], Int32)

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

Declaration

public byte[] EncryptBytes(byte[] input, int numBytes)

Parameters

Type	Name	Description
System.Byte[]	input	Input byte array
System.Int32	numBytes	Number of bytes to encrypt

Returns

Type	Description
System.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

EncryptStream(Stream, Stream, Int32)

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)

Parameters

Type	Name	Description
System.IO.Stream	output	Output stream
System.IO.Stream	input	Input stream
System.Int32	howManyBytesToProcessAtTime	How many bytes to read and write at time, default is 1024

EncryptStreamAsync(Stream, Stream, Int32)

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)

Parameters

Type	Name	Description
System.IO.Stream	output	Output stream
System.IO.Stream	input	Input stream
System.Int32	howManyBytesToProcessAtTime	How many bytes to read and write at time, default is 1024

Returns

Type	Description
System.Threading.Tasks.Task

EncryptString(String)

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

Declaration

public byte[] EncryptString(string input)

Parameters

Type	Name	Description
System.String	input	Input string

Returns

Type	Description
System.Byte[]	Byte array that contains encrypted bytes

Remarks

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

Finalize()

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

Declaration

protected void Finalize()

Implements

System.IDisposable