HKDF.Expand Method

Definition

Namespace:

System.Security.Cryptography

Assembly:

System.Security.Cryptography.dll

Overloads

Expand(HashAlgorithmName, Byte[], Int32, Byte[])	Performs the HKDF-Expand function See section 2.3 of RFC5869.
Expand(HashAlgorithmName, ReadOnlySpan<Byte>, Span<Byte>, ReadOnlySpan<Byte>)	Performs the HKDF-Expand function. See section 2.3 of RFC5869.

Expand(HashAlgorithmName, Byte[], Int32, Byte[])

Source:

HKDF.cs

Performs the HKDF-Expand function See section 2.3 of RFC5869.

public static byte[] Expand (System.Security.Cryptography.HashAlgorithmName hashAlgorithmName, byte[] prk, int outputLength, byte[]? info = default);

static member Expand : System.Security.Cryptography.HashAlgorithmName * byte[] * int * byte[] -> byte[]

Public Shared Function Expand (hashAlgorithmName As HashAlgorithmName, prk As Byte(), outputLength As Integer, Optional info As Byte() = Nothing) As Byte()

Parameters

hashAlgorithmName

HashAlgorithmName

The hash algorithm used for HMAC operations.

prk

Byte[]

The pseudorandom key that is at least as long as the output byte array of the specified hash algorithm (usually the output from the Extract step).

outputLength

Int32

The length of the output keying material.

info

Byte[]

The optional context and application specific information.

Returns

Byte[]

The output keying material.

Exceptions

ArgumentNullException

prkis null.

ArgumentOutOfRangeException

outputLength is less than 1.

Expand(HashAlgorithmName, ReadOnlySpan<Byte>, Span<Byte>, ReadOnlySpan<Byte>)

Source:

HKDF.cs

Performs the HKDF-Expand function. See section 2.3 of RFC5869.

public:
 static void Expand(System::Security::Cryptography::HashAlgorithmName hashAlgorithmName, ReadOnlySpan<System::Byte> prk, Span<System::Byte> output, ReadOnlySpan<System::Byte> info);

public static void Expand (System.Security.Cryptography.HashAlgorithmName hashAlgorithmName, ReadOnlySpan<byte> prk, Span<byte> output, ReadOnlySpan<byte> info);

static member Expand : System.Security.Cryptography.HashAlgorithmName * ReadOnlySpan<byte> * Span<byte> * ReadOnlySpan<byte> -> unit

Public Shared Sub Expand (hashAlgorithmName As HashAlgorithmName, prk As ReadOnlySpan(Of Byte), output As Span(Of Byte), info As ReadOnlySpan(Of Byte))

Parameters

hashAlgorithmName

HashAlgorithmName

The hash algorithm used for HMAC operations.

prk

ReadOnlySpan<Byte>

The pseudorandom key that is at least as long as as the output byte array of the specified hash algorithm (usually the output from the Extract step).

output

Span<Byte>

The destination buffer to receive the output keying material.

info

ReadOnlySpan<Byte>

The context and application specific information (can be an empty span).

Exceptions

ArgumentException

output is empty, or is larger than the maximum allowed length.