MAC

The MAC function uses a user-specified MAC function to return the hashed MAC value of a RAW or CLOB value. The MAC function is available in three forms:

MAC
  (<src> IN RAW, <typ> IN INTEGER, <key> IN RAW) RETURN RAW

MAC
  (<src> IN CLOB, <typ> IN INTEGER, <key> IN RAW) RETURN RAW

Parameters

src

src specifies the value for which the MAC value will be generated. Specify a RAW, BLOB, or CLOB value.

typ

typ specifies the MAC function used. Advanced Server supports the MAC functions listed below.

MAC Functions
HMAC_MD5	CONSTANT INTEGER := 1;
HMAC_SH1	CONSTANT INTEGER := 2;

key

key specifies the key that will be used to calculate the hashed MAC value.

Examples

The following example finds the hashed MAC value of the string cleartext source:

DECLARE
  typ INTEGER := DBMS_CRYPTO.HMAC_MD5;
  key RAW(100) := 'my secret key';
  mac_value RAW(100);
BEGIN

  mac_value := DBMS_CRYPTO.MAC('cleartext source', typ, key);

END;

DBMS_CRYPTO.MAC uses a key value of my secret key when calculating the MAC value of cleartext source.