C# Класс Org.BouncyCastle.Crypto.Generators.Poly1305KeyGenerator

Generates keys for the Poly1305 MAC.

Poly1305 keys are 256 bit keys consisting of a 128 bit secret key used for the underlying block cipher followed by a 128 bit {@code r} value used for the polynomial portion of the Mac.
The {@code r} value has a specific format with some bits required to be cleared, resulting in an effective 106 bit key.
A separately generated 256 bit key can be modified to fit the Poly1305 key format by using the {@link #clamp(byte[])} method to clear the required bits.

Наследование: Org.BouncyCastle.Crypto.CipherKeyGenerator

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Открытые методы

Метод	Описание
CheckKey ( byte key ) : void	Checks a 32 byte key for compliance with the Poly1305 key requirements, e.g. `k[0] ... k[15], r[0] ... r[15]` with the required bits in `r` cleared as per Clamp(byte[]).
Clamp ( byte key ) : void	Modifies an existing 32 byte key value to comply with the requirements of the Poly1305 key by clearing required bits in the `r` (second 16 bytes) portion of the key. Specifically: r[3], r[7], r[11], r[15] have top four bits clear (i.e., are {0, 1, . . . , 15}) r[4], r[8], r[12] have bottom two bits clear (i.e., are in {0, 4, 8, . . . , 252})

Защищенные методы

Метод	Описание
engineGenerateKey ( ) : byte[]	Generates a 256 bit key in the format required for Poly1305 - e.g. `k[0] ... k[15], r[0] ... r[15]` with the required bits in `r` cleared as per Clamp(byte[]).
engineInit ( KeyGenerationParameters param ) : void	Initialises the key generator. Poly1305 keys are always 256 bits, so the key length in the provided parameters is ignored.

Приватные методы

Метод	Описание
CheckMask ( byte b, byte mask ) : void

Описание методов

CheckKey() публичный статический Метод

Checks a 32 byte key for compliance with the Poly1305 key requirements, e.g. k[0] ... k[15], r[0] ... r[15] with the required bits in r cleared as per Clamp(byte[]).

if the key is of the wrong length, or has invalid bits set /// in the r portion of the key.

public static CheckKey ( byte key ) : void
key	byte	Key.
Результат	void

Clamp() публичный статический Метод

Modifies an existing 32 byte key value to comply with the requirements of the Poly1305 key by clearing required bits in the r (second 16 bytes) portion of the key.
Specifically:

r[3], r[7], r[11], r[15] have top four bits clear (i.e., are {0, 1, . . . , 15})
r[4], r[8], r[12] have bottom two bits clear (i.e., are in {0, 4, 8, . . . , 252})

public static Clamp ( byte key ) : void
key	byte	a 32 byte key value `k[0] ... k[15], r[0] ... r[15]`
Результат	void

engineGenerateKey() защищенный Метод

Generates a 256 bit key in the format required for Poly1305 - e.g. k[0] ... k[15], r[0] ... r[15] with the required bits in r cleared as per Clamp(byte[]).

protected engineGenerateKey ( ) : byte[]
Результат	byte[]

engineInit() защищенный Метод

Initialises the key generator.

Poly1305 keys are always 256 bits, so the key length in the provided parameters is ignored.

protected engineInit ( KeyGenerationParameters param ) : void
param	Org.BouncyCastle.Crypto.KeyGenerationParameters
Результат	void