Some of the commands available for use within iRules are known as utility commands. You use most of these commands to ensure data integrity. Table 1 lists and describes the utility commands that you can use within iRules.

Utility Command Description
b64encode Returns a string that is base-64 encoded, or if an error occurs, an empty string.
b64decode Returns a string that is base-64 decoded, or if an error occurs, an empty string.
crc32 Returns the crc32 checksum for the provided string, or if an error occurs, an empty string. Used to ensure data integrity.
md5 Returns the RSA Data Security, Inc. MD5 Message Digest Algorithm (md5) message digest of the provided string, or if an error occurs, an empty string. Used to ensure data integrity.
sha1 Returns the Secure Hash Algorithm version 1.0 (SHA1) message digest of the provided string, or if an error occurs, an empty string. Used to ensure data integrity.