HMAC()

Creates a hash-based message authentication code (HMAC) for the given message combined with a given secret key using an optional algorithm and encoding.

HMACs are used to verify the data integrity and authenticity of a transmitted message.

The hash function used by the HMAC function depends on the algorithm specified.

HMAC( message=object, key=object, algorithm=string, encoding=string );

Returns: String

Argument Description Default
message
object, required

The message to be hashed. Can be a string or a byte array.
key
object, required

The secret cryptographic key to be combined with the message and hashed. Can be a string or a byte array.
algorithm
string, optional

The algorithm to use for hashing your input. The following values are supported:

  • HmacMD5
  • HmacSHA1
  • HmacSHA256
  • HMACSHA384
  • HMACSHA512

HmacMD5
encoding
string, optional

The character encoding to use when converting the message to bytes. Must be a character encoding name recognized by the Java runtime.

  • utf-8
  • iso-8859-1
  • windows-1252
  • us-ascii
  • shift_jis
  • iso-2022-jp
  • euc-jp
  • euc-kr
  • big5
  • euc-cn
  • utf-16

Alias: charset

Examples

    message = 'this is a test';
    key = 'ABC123';

    // Using the required fields only
    result = HMAC( message, key );
    writeDump( result ); // 776770430C93778AD6F91B43A4A30B69


    // Using the optional algorithm parameter (HmacSHA1)
    algorithm = 'HmacSHA1';
    result = HMAC( message, key, algorithm );
    writeDump( result ); // 049E53BAE339C4A05587D7BBBA2857548E8FC327


    // Using the optional algorithm parameter (HmacSHA256)
    algorithm = 'HmacSHA256';
    result = HMAC( message, key, algorithm );
    writeDump( result ); // 0503949602EDE3FF61C84F4CE51C99EEA2961CAA144AEE552F7D120AD6A60D7D


    // Using the optional encoding parameter (UTF-8)
    encoding = 'UTF-8';
    result = HMAC( message, key, algorithm, encoding );
    writeDump( result ); // 0503949602EDE3FF61C84F4CE51C99EEA2961CAA144AEE552F7D120AD6A60D7D

See also