Replace M2Crypto RC4 with python-cryptography ARC4
This patch removes the dependency on M2Crypto in favor for cryptography.
Cryptography is more strict about the key size and doesn't support
non-standard key sizes:
>>> from M2Crypto import RC4
>>> from ipaserver.dcerpc import arcfour_encrypt
>>> RC4.RC4(b'key').update(b'data')
'o\r@\x8c'
>>> arcfour_encrypt(b'key', b'data')
Traceback (most recent call last):
...
ValueError: Invalid key size (24) for RC4.
Standard key sizes 40, 56, 64, 80, 128, 192 and 256 are supported:
>>> arcfour_encrypt(b'key12', b'data')
'\xcd\xf80d'
>>> RC4.RC4(b'key12').update(b'data')
'\xcd\xf80d'
http://cryptography.readthedocs.org/en/latest/hazmat/primitives/symmetric-encryption/#cryptography.hazmat.primitives.ciphers.algorithms.ARC4https://fedorahosted.org/freeipa/ticket/5148
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Jan Cholasta <jcholast@redhat.com>