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authordrebs <drebs@leap.se>2013-06-05 12:48:41 -0300
committerdrebs <drebs@leap.se>2013-06-05 12:48:41 -0300
commit04e3a6e65bfea724dec8de47a7d8195ca3c3674c (patch)
tree056a0ab11e0289623933479a70f4ee832d7feefb /src/leap/common
parentdbbf33d27268266088ee1ab15fc04cef33259250 (diff)
Move symmetric encryption code to leap.soledad.
Diffstat (limited to 'src/leap/common')
-rw-r--r--src/leap/common/crypto.py114
-rw-r--r--src/leap/common/tests/test_crypto.py88
2 files changed, 0 insertions, 202 deletions
diff --git a/src/leap/common/crypto.py b/src/leap/common/crypto.py
deleted file mode 100644
index 7f80a8a..0000000
--- a/src/leap/common/crypto.py
+++ /dev/null
@@ -1,114 +0,0 @@
-# -*- coding: utf-8 -*-
-# crypto.py
-# Copyright (C) 2013 LEAP
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program 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 General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program. If not, see <http://www.gnu.org/licenses/>.
-
-import os
-import binascii
-
-from Crypto.Cipher import AES
-from Crypto.Util import Counter
-from leap.common.check import leap_assert, leap_assert_type
-
-#
-# encryption methods
-#
-
-class EncryptionMethods(object):
- """
- Representation of encryption methods that can be used.
- """
-
- AES_256_CTR = 'aes-256-ctr'
-
-
-class UnknownEncryptionMethod(Exception):
- """
- Raised when trying to encrypt/decrypt with unknown method.
- """
- pass
-
-
-#
-# encrypt/decrypt functions
-#
-
-# In the future, we might want to implement other encryption schemes and
-# possibly factor out the actual encryption/decryption routines of the
-# following functions to specific classes, while not changing the API.
-
-def encrypt_sym(data, key, method=EncryptionMethods.AES_256_CTR):
- """
- Encrypt C{data} with C{key}, using C{method} encryption method.
-
- :param data: The data to be encrypted.
- :type data: str
- :param key: The key used to encrypt C{data} (must be 256 bits long).
- :type key: str
- :param method: The encryption method to use.
- :type method: str
-
- :return: A tuple with the initial value and the encrypted data.
- :rtype: (long, str)
- """
- leap_assert_type(key, str)
-
- # AES-256 in CTR mode
- if method == EncryptionMethods.AES_256_CTR:
- leap_assert(
- len(key) == 32, # 32 x 8 = 256 bits.
- 'Wrong key size: %s bits (must be 256 bits long).' % (len(key)*8))
- iv = os.urandom(8)
- ctr = Counter.new(64, prefix=iv)
- cipher = AES.new(key=key, mode=AES.MODE_CTR, counter=ctr)
- return binascii.b2a_base64(iv), cipher.encrypt(data)
-
- # raise if method is unknown
- raise UnknownEncryptionMethod('Unkwnown method: %s' % method)
-
-
-def decrypt_sym(data, key, method=EncryptionMethods.AES_256_CTR, **kwargs):
- """
- Decrypt C{data} with C{key} using C{method} encryption method.
-
- :param data: The data to be decrypted.
- :type data: str
- :param key: The key used to decrypt C{data} (must be 256 bits long).
- :type key: str
- :param method: The encryption method to use.
- :type method: str
- :param kwargs: Other parameters specific to each encryption method.
- :type kwargs: dict
-
- :return: The decrypted data.
- :rtype: str
- """
- leap_assert_type(key, str)
-
- # AES-256 in CTR mode
- if method == EncryptionMethods.AES_256_CTR:
- # assert params
- leap_assert(
- len(key) == 32, # 32 x 8 = 256 bits.
- 'Wrong key size: %s (must be 256 bits long).' % len(key))
- leap_assert(
- 'iv' in kwargs,
- 'AES-256-CTR needs an initial value given as.')
- ctr = Counter.new(64, prefix=binascii.a2b_base64(kwargs['iv']))
- cipher = AES.new(key=key, mode=AES.MODE_CTR, counter=ctr)
- return cipher.decrypt(data)
-
- # raise if method is unknown
- raise UnknownEncryptionMethod('Unkwnown method: %s' % method)
diff --git a/src/leap/common/tests/test_crypto.py b/src/leap/common/tests/test_crypto.py
deleted file mode 100644
index ae7dc71..0000000
--- a/src/leap/common/tests/test_crypto.py
+++ /dev/null
@@ -1,88 +0,0 @@
-## -*- coding: utf-8 -*-
-# test_crypto.py
-# Copyright (C) 2013 LEAP
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program 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 General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program. If not, see <http://www.gnu.org/licenses/>.
-
-
-"""
-Tests for the crypto submodule.
-"""
-
-
-import os
-import binascii
-
-
-from leap.common.testing.basetest import BaseLeapTest
-from leap.common import crypto
-from Crypto import Random
-
-
-class CryptoTestCase(BaseLeapTest):
-
- def setUp(self):
- pass
-
- def tearDown(self):
- pass
-
- def test_encrypt_decrypt_sym(self):
- # generate 256-bit key
- key = Random.new().read(32)
- iv, cyphertext = crypto.encrypt_sym(
- 'data', key,
- method=crypto.EncryptionMethods.AES_256_CTR)
- self.assertTrue(cyphertext is not None)
- self.assertTrue(cyphertext != '')
- self.assertTrue(cyphertext != 'data')
- plaintext = crypto.decrypt_sym(
- cyphertext, key, iv=iv,
- method=crypto.EncryptionMethods.AES_256_CTR)
- self.assertEqual('data', plaintext)
-
- def test_decrypt_with_wrong_iv_fails(self):
- key = Random.new().read(32)
- iv, cyphertext = crypto.encrypt_sym(
- 'data', key,
- method=crypto.EncryptionMethods.AES_256_CTR)
- self.assertTrue(cyphertext is not None)
- self.assertTrue(cyphertext != '')
- self.assertTrue(cyphertext != 'data')
- # get a different iv by changing the first byte
- rawiv = binascii.a2b_base64(iv)
- wrongiv = rawiv
- while wrongiv == rawiv:
- wrongiv = os.urandom(1) + rawiv[1:]
- plaintext = crypto.decrypt_sym(
- cyphertext, key, iv=binascii.b2a_base64(wrongiv),
- method=crypto.EncryptionMethods.AES_256_CTR)
- self.assertNotEqual('data', plaintext)
-
- def test_decrypt_with_wrong_key_fails(self):
- key = Random.new().read(32)
- iv, cyphertext = crypto.encrypt_sym(
- 'data', key,
- method=crypto.EncryptionMethods.AES_256_CTR)
- self.assertTrue(cyphertext is not None)
- self.assertTrue(cyphertext != '')
- self.assertTrue(cyphertext != 'data')
- wrongkey = Random.new().read(32) # 256-bits key
- # ensure keys are different in case we are extremely lucky
- while wrongkey == key:
- wrongkey = Random.new().read(32)
- plaintext = crypto.decrypt_sym(
- cyphertext, wrongkey, iv=iv,
- method=crypto.EncryptionMethods.AES_256_CTR)
- self.assertNotEqual('data', plaintext)