Update decode_cipher doc text about encryption ciphers
Point to the new doc file location and specify that
we don't support keycount/ivopts.
@@ -952,9 +952,11 @@ def replace_xenserver_image_with_coalesced_vhd(image_file):
def decode_cipher(cipher_spec, key_size):
"""Decode a dm-crypt style cipher specification string
- The assumed format being cipher[:keycount]-chainmode-ivmode[:ivopts] as
- documented under linux/Documentation/device-mapper/dm-crypt.txt in the
- kernel source tree.
+ The assumed format being cipher-chainmode-ivmode, similar to that
+ documented under
+ linux/Documentation/admin-guide/device-mapper/dm-crypt.txt in the
+ kernel source tree. Cinder does not support the [:keycount] or
+ [:ivopts] options.
"""
cipher_alg, cipher_mode, ivgen_alg = cipher_spec.split('-')
cipher_alg = cipher_alg + '-' + str(key_size)
