test_keywrap.doctest - test keywrap functions

Copyright (C) 2014 Arthur de Jong

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
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02110-1301 USA


>>> from pskc.aeskw import wrap, unwrap


Wrap 128 bits of Key Data with a 128-bit KEK (test vector 4.1 from RFC 3394).

>>> key = '000102030405060708090A0B0C0D0E0F'.decode('hex')
>>> plaintext = '00112233445566778899AABBCCDDEEFF'.decode('hex')
>>> ciphertext = '1FA68B0A8112B447AEF34BD8FB5A7B829D3E862371D2CFE5'.decode('hex')
>>> wrap(plaintext, key) == ciphertext
True
>>> unwrap(ciphertext, key) == plaintext
True


Wrap 128 bits of Key Data with a 192-bit KEK (test vector 4.2 from RFC 3394).

>>> key = '000102030405060708090A0B0C0D0E0F1011121314151617'.decode('hex')
>>> plaintext = '00112233445566778899AABBCCDDEEFF'.decode('hex')
>>> ciphertext = '96778B25AE6CA435F92B5B97C050AED2468AB8A17AD84E5D'.decode('hex')
>>> wrap(plaintext, key) == ciphertext
True
>>> unwrap(ciphertext, key) == plaintext
True


Wrap 128 bits of Key Data with a 256-bit KEK (test vector 4.3 from RFC 3394).

>>> key = '000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F'.decode('hex')
>>> plaintext = '00112233445566778899AABBCCDDEEFF'.decode('hex')
>>> ciphertext = '64E8C3F9CE0F5BA263E9777905818A2A93C8191E7D6E8AE7'.decode('hex')
>>> wrap(plaintext, key) == ciphertext
True
>>> unwrap(ciphertext, key) == plaintext
True


Wrap 192 bits of Key Data with a 192-bit KEK (test vector 4.4 from RFC 3394).

>>> key = '000102030405060708090A0B0C0D0E0F1011121314151617'.decode('hex')
>>> plaintext = '00112233445566778899AABBCCDDEEFF0001020304050607'.decode('hex')
>>> ciphertext = '031D33264E15D33268F24EC260743EDCE1C6C7DDEE725A936BA814915C6762D2'.decode('hex')
>>> wrap(plaintext, key) == ciphertext
True
>>> unwrap(ciphertext, key) == plaintext
True


Wrap 192 bits of Key Data with a 256-bit KEK (test vector 4.5 from RFC 3394).

>>> key = '000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F'.decode('hex')
>>> plaintext = '00112233445566778899AABBCCDDEEFF0001020304050607'.decode('hex')
>>> ciphertext = 'A8F9BC1612C68B3FF6E6F4FBE30E71E4769C8B80A32CB8958CD5D17D6B254DA1'.decode('hex')
>>> wrap(plaintext, key) == ciphertext
True
>>> unwrap(ciphertext, key) == plaintext
True


Wrap 256 bits of Key Data with a 256-bit KEK (test vector 4.6 from RFC 3394).

>>> key = '000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F'.decode('hex')
>>> plaintext = '00112233445566778899AABBCCDDEEFF000102030405060708090A0B0C0D0E0F'.decode('hex')
>>> ciphertext = '28C9F404C4B810F4CBCCB35CFB87F8263F5786E2D80ED326CBC7F0E71A99F43BFB988B9B7A02DD21'.decode('hex')
>>> wrap(plaintext, key) == ciphertext
True
>>> unwrap(ciphertext, key) == plaintext
True


Mangling the ciphertext and unwrapping results in an exception:

>>> ciphertext = 'XX' + ciphertext[2:]
>>> unwrap(ciphertext, key)
Traceback (most recent call last):
    ...
DecryptionError: IV does not match
>>> ciphertext = ciphertext[2:]
>>> unwrap(ciphertext, key)
Traceback (most recent call last):
    ...
DecryptionError: Ciphertext length wrong


Wrap 20 octets with a 192-bit key (first example from section 6 of RFC 5649).

>>> key = '5840df6e29b02af1ab493b705bf16ea1ae8338f4dcc176a8'.decode('hex')
>>> plaintext = 'c37b7e6492584340bed12207808941155068f738'.decode('hex')
>>> ciphertext = '138bdeaa9b8fa7fc61f97742e72248ee5ae6ae5360d1ae6a5f54f373fa543b6a'.decode('hex')
>>> wrap(plaintext, key) == ciphertext
True
>>> unwrap(ciphertext, key) == plaintext
True
>>> wrap(plaintext, key, pad=False)  # disable padding
Traceback (most recent call last):
    ...
EncryptionError: Plaintext length wrong
>>> unwrap(ciphertext, key, pad=False)
Traceback (most recent call last):
    ...
DecryptionError: IV does not match


Wrap 7 octets with a 192-bit key (second example from section 6 of RFC 5649).

>>> key = '5840df6e29b02af1ab493b705bf16ea1ae8338f4dcc176a8'.decode('hex')
>>> plaintext = '466f7250617369'.decode('hex')
>>> ciphertext = 'afbeb0f07dfbf5419200f2ccb50bb24f'.decode('hex')
>>> wrap(plaintext, key) == ciphertext
True
>>> unwrap(ciphertext, key) == plaintext
True
>>> wrap(plaintext, key, pad=False)  # disable padding
Traceback (most recent call last):
    ...
EncryptionError: Plaintext length wrong
>>> unwrap(ciphertext, key, pad=False)
Traceback (most recent call last):
    ...
DecryptionError: Ciphertext length wrong


Normally padding is only done if needed but it can be forced.

>>> key = '000102030405060708090A0B0C0D0E0F'.decode('hex')
>>> plaintext = '00112233445566778899AABBCCDDEEFF'.decode('hex')
>>> ciphertext = '1FA68B0A8112B447AEF34BD8FB5A7B829D3E862371D2CFE5'.decode('hex')
>>> wrap(plaintext, key) == ciphertext
True
>>> unwrap(ciphertext, key) == plaintext
True
>>> ciphertext = '2cef0c9e30de26016c230cb78bc60d51b1fe083ba0c79cd5'.decode('hex')
>>> wrap(plaintext, key, pad=True) == ciphertext
True
>>> unwrap(ciphertext, key) == plaintext
True
>>> unwrap(ciphertext, key, pad=False)  # disabling padding fails IV check
Traceback (most recent call last):
    ...
DecryptionError: IV does not match


Padding can also be disabled. This also disables the shortcut for small
plaintexts as described in RFC 5649.

>>> key = '000102030405060708090A0B0C0D0E0F'.decode('hex')
>>> plaintext = '0011223344556677'.decode('hex')
>>> ciphertext = 'f4740052e82a225174ce86fbd7b805e7'.decode('hex')
>>> wrap(plaintext, key) == ciphertext
True
>>> unwrap(ciphertext, key) == plaintext
True
>>> wrap(plaintext, key, pad=False)  # disable padding
Traceback (most recent call last):
    ...
EncryptionError: Plaintext length wrong
>>> unwrap(ciphertext, key, pad=False)
Traceback (most recent call last):
    ...
DecryptionError: Ciphertext length wrong


Lastly, an explicit IV can be set but this disables the padding functionality.

>>> key = '000102030405060708090A0B0C0D0E0F'.decode('hex')
>>> plaintext = '0011223344556677'.decode('hex')
>>> iv = '1010101010101010'.decode('hex')
>>> wrap(plaintext, key, iv)
Traceback (most recent call last):
    ...
EncryptionError: Plaintext length wrong
>>> plaintext = '00112233445566778899AABBCCDDEEFF'.decode('hex')
>>> ciphertext = '4cd926c570e19c35ace71d59a1062dae850e6a709066e0bf'.decode('hex')
>>> wrap(plaintext, key, iv) == ciphertext
True
>>> unwrap(ciphertext, key, iv) == plaintext
True