def gen_iv(cls, n=13):
"""Returns a random IV of size specified by n.
:param int n: Number of bytes
:return: IV
:rtype: str
"""
return gen_random_data(n)
def gen_key(cls, n=16):
"""Returns a random key of size specified by n.
:param int n: Number of bytes
:return: Key
:rtype: str
"""
return gen_random_data(n)