HMACMD5 Constructors

Definition

Initializes a new instance of the HMACMD5 class.

Overloads

HMACMD5()

Initializes a new instance of the HMACMD5 class by using a randomly generated key.

HMACMD5(Byte[])

Initializes a new instance of the HMACMD5 class by using the specified key.

HMACMD5()

Initializes a new instance of the HMACMD5 class by using a randomly generated key.

public:
 HMACMD5();
public HMACMD5 ();
Public Sub New ()

Remarks

HMACMD5 is a type of keyed hash algorithm that is constructed from the MD5 hash function and used as a Hash-based Message Authentication Code (HMAC). The HMAC process mixes a secret key with the message data, hashes the result with the hash function, mixes that hash value with the secret key again, and then applies the hash function a second time. The output hash is 128 bits in length.

This constructor uses a 64-byte, randomly generated key.

Due to collision problems with MD5, Microsoft recommends SHA256.

See also

HMACMD5(Byte[])

Initializes a new instance of the HMACMD5 class by using the specified key.

public:
 HMACMD5(cli::array <System::Byte> ^ key);
public HMACMD5 (byte[] key);
new System.Security.Cryptography.HMACMD5 : byte[] -> System.Security.Cryptography.HMACMD5
Public Sub New (key As Byte())

Parameters

key
Byte[]

The secret key for HMACMD5 encryption. The key can be any length, but if it is more than 64 bytes long it will be hashed (using SHA-1) to derive a 64-byte key. Therefore, the recommended size of the secret key is 64 bytes.

Exceptions

The key parameter is null.

Examples

For an example of how to use this constructor, see the HMACMD5 class.

Remarks

HMACMD5 is a type of keyed hash algorithm that is constructed from the MD5 hash function and used as a Hash-based Message Authentication Code (HMAC). The HMAC process mixes a secret key with the message data, hashes the result with the hash function, mixes that hash value with the secret key again, and then applies the hash function a second time. The output hash is 128 bits in length.

This constructor uses a key you provide to create the HMACMD5 object.

Due to collision problems with MD5, Microsoft recommends SHA256.

See also

Applies to