HMAC

Syntax

HMAC SHA1 KeyData=<keydata> SourceData=<sourcedata> Result=<var> 

Description

Computes a standard RFC 2104 keyed-hash message authentication code using the SHA-1 hash algorithm.

Parameters

<keydata>

The key string to be used.

<sourcedata>

The data to be HMACed.

<var>

The variable to receive the MAC.

Remarks

A Message Authentication Code is a number computed from the contents of a text message that is used to prove the integrity of a message. Typically, message authentication codes are used between two parties that share a secret key in order to validate information transmitted between these parties.

SHA-1 is the only hash algorithm supported at this time.

The MAC produced by this statement is 20 bytes in length.

Example

Global plainText = "The plain text."
Global secret
Global decryption

HMAC SHA1 KeyData="My authentication key" SourceData=plainText Result=mac
Base64Encode SourceData=mac Result=b64mac
MessageBox Title="MAC" Text=b64mac

The above example displays the base-64-encoded message authentication code in a message box.