HMAC Class Reference

Public Member Functions
def	__init__

Data Fields
	digestmod
	outer
	inner
	digest_size

Detailed Description

RFC2104 HMAC class.

This supports the API for Cryptographic Hash Functions (PEP 247).

Definition at line 17 of file hmac.py.

Constructor & Destructor Documentation

def __init__	(		self,
			key,
			msg = None,
			digestmod = None
	)

Create a new HMAC object.

key:       key for the keyed hash object.
msg:       Initial input for the hash, if provided.
digestmod: A module supporting PEP 247. Defaults to the md5 module.

Definition at line 23 of file hmac.py.

    def __init__(self, key, msg = None, digestmod = None):
        """Create a new HMAC object.

        key:       key for the keyed hash object.
        msg:       Initial input for the hash, if provided.
        digestmod: A module supporting PEP 247. Defaults to the md5 module.
        """
        if digestmod == None:
            import md5
            digestmod = md5

        self.digestmod = digestmod
        self.outer = digestmod.new()
        self.inner = digestmod.new()
        self.digest_size = digestmod.digest_size

        blocksize = 64
        ipad = "\x36" * blocksize
        opad = "\x5C" * blocksize

        if len(key) > blocksize:
            key = digestmod.new(key).digest()

        key = key + chr(0) * (blocksize - len(key))
        self.outer.update(_strxor(key, opad))
        self.inner.update(_strxor(key, ipad))
        if (msg):
            self.update(msg)