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Diffstat (limited to 'src/leap/soledad/crypto.py')
| -rw-r--r-- | src/leap/soledad/crypto.py | 153 |
1 files changed, 0 insertions, 153 deletions
diff --git a/src/leap/soledad/crypto.py b/src/leap/soledad/crypto.py deleted file mode 100644 index e020eee6..00000000 --- a/src/leap/soledad/crypto.py +++ /dev/null @@ -1,153 +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/>. - - -""" -Cryptographic utilities for Soledad. -""" - - -import hmac -import hashlib - - -from leap.common import crypto - - -class NoSymmetricSecret(Exception): - """ - Raised when trying to get a hashed passphrase. - """ - - -class SoledadCrypto(object): - """ - General cryptographic functionality. - """ - - MAC_KEY_LENGTH = 64 - - def __init__(self, soledad): - """ - Initialize the crypto object. - - @param soledad: A Soledad instance for key lookup. - @type soledad: leap.soledad.Soledad - """ - self._soledad = soledad - - def encrypt_sym(self, data, key, - method=crypto.EncryptionMethods.AES_256_CTR): - """ - Encrypt C{data} using a {password}. - - Currently, the only encryption method supported is AES-256 CTR mode. - - @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) - """ - return crypto.encrypt_sym(data, key, method) - - def decrypt_sym(self, data, key, - method=crypto.EncryptionMethods.AES_256_CTR, **kwargs): - """ - Decrypt data using symmetric secret. - - Currently, the only encryption method supported is AES-256 CTR mode. - - @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 - """ - return crypto.decrypt_sym(data, key, method, **kwargs) - - def doc_passphrase(self, doc_id): - """ - Generate a passphrase for symmetric encryption of document's contents. - - The password is derived using HMAC having sha256 as underlying hash - function. The key used for HMAC are the first - C{soledad.REMOTE_STORAGE_SECRET_KENGTH} bytes of Soledad's storage - secret stripped from the first MAC_KEY_LENGTH characters. The HMAC - message is C{doc_id}. - - @param doc_id: The id of the document that will be encrypted using - this passphrase. - @type doc_id: str - - @return: The passphrase. - @rtype: str - - @raise NoSymmetricSecret: if no symmetric secret was supplied. - """ - if self.secret is None: - raise NoSymmetricSecret() - return hmac.new( - self.secret[ - self.MAC_KEY_LENGTH: - self._soledad.REMOTE_STORAGE_SECRET_LENGTH], - doc_id, - hashlib.sha256).digest() - - def doc_mac_key(self, doc_id): - """ - Generate a key for calculating a MAC for a document whose id is - C{doc_id}. - - The key is derived using HMAC having sha256 as underlying hash - function. The key used for HMAC is the first MAC_KEY_LENGTH characters - of Soledad's storage secret. The HMAC message is C{doc_id}. - - @param doc_id: The id of the document. - @type doc_id: str - - @return: The key. - @rtype: str - - @raise NoSymmetricSecret: if no symmetric secret was supplied. - """ - if self.secret is None: - raise NoSymmetricSecret() - return hmac.new( - self.secret[:self.MAC_KEY_LENGTH], - doc_id, - hashlib.sha256).digest() - - # - # secret setters/getters - # - - def _get_secret(self): - return self._soledad.storage_secret - - secret = property( - _get_secret, doc='The secret used for symmetric encryption') |