HKDF.Extract Method

HKDF Extract function according to section 2.2 of RFC 5869.

public static byte[] Extract(HashingAlgorithmId hashingAlgorithmId, byte[] ikm, byte[] salt = null)

Type	Name	Description
HashingAlgorithmId	hashingAlgorithmId	The hash algorithm for HMAC operations.
Byte[]	ikm	A byte array that contains input keying material. This is the 'IKM' parameter from RFC 5869.
Byte[]	salt	A byte array that contains the salt. When null or empty salt is specified, this method will use a zero-filled salt with size equal to the hash size of `hashingAlgorithmId`. This is the 'salt' parameter from RFC 5869.

Type	Description
Byte[]	A byte array that contains the pseudorandom key (the 'PRK' output from RFC 5869).

Type	Condition
ArgumentNullException	The `ikm` is null.
ArgumentException	The `ikm` is an empty array, or `hashingAlgorithmId` is not supported.

HKDF Extract function according to section 2.2 of RFC 5869.

public static int Extract(HashingAlgorithmId hashingAlgorithmId, ArraySegment<byte> ikm, ArraySegment<byte> salt, ArraySegment<byte> prk)

Type	Name	Description
HashingAlgorithmId	hashingAlgorithmId	The hash algorithm for HMAC operations.
ArraySegment<Byte>	ikm	An ArraySegment<T> that contains input keying material. This is the 'IKM' parameter from RFC 5869.
ArraySegment<Byte>	salt	An ArraySegment<T> that contains the salt. When an empty salt is specified, this method will use a zero-filled salt with size equal to the hash size of `hashingAlgorithmId`. This is the 'salt' parameter from RFC 5869.
ArraySegment<Byte>	prk	An ArraySegment<T> that will receive the pseudorandom key (the 'PRK' output from RFC 5869). The length of `prk` must be equal to or greater than the hash size of `hashingAlgorithmId`.

Type	Description
Int32	The number of bytes written to `prk`.

Type	Condition
ArgumentException	The `ikm` is empty, or `hashingAlgorithmId` is not supported.