trove/trove/common/crypto_utils.py

80 lines
2.5 KiB
Python

# Copyright 2016 Tesora, Inc.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#
# Encryption/decryption handling
from Crypto.Cipher import AES
from Crypto import Random
import hashlib
from oslo_utils import encodeutils
import random
import six
import string
from trove.common import stream_codecs
IV_BIT_COUNT = 16
def encode_data(data):
# NOTE(zhaochao) No need to encoding string object any more,
# as Base64Codec is now using oslo_serialization.base64 which
# could take care of this.
return stream_codecs.Base64Codec().serialize(data)
def decode_data(data):
return stream_codecs.Base64Codec().deserialize(data)
# Pad the data string to an multiple of pad_size
def pad_for_encryption(data, pad_size=IV_BIT_COUNT):
pad_count = pad_size - (len(data) % pad_size)
return data + six.int2byte(pad_count) * pad_count
# Unpad the data string by stripping off excess characters
def unpad_after_decryption(data):
return data[:len(data) - six.indexbytes(data, -1)]
def encrypt_data(data, key, iv_bit_count=IV_BIT_COUNT):
data = encodeutils.to_utf8(data)
key = encodeutils.to_utf8(key)
md5_key = hashlib.md5(key).hexdigest()
iv = Random.new().read(iv_bit_count)
iv = iv[:iv_bit_count]
aes = AES.new(md5_key, AES.MODE_CBC, iv)
data = pad_for_encryption(data, iv_bit_count)
encrypted = aes.encrypt(data)
return iv + encrypted
def decrypt_data(data, key, iv_bit_count=IV_BIT_COUNT):
key = encodeutils.to_utf8(key)
md5_key = hashlib.md5(key).hexdigest()
iv = data[:iv_bit_count]
aes = AES.new(md5_key, AES.MODE_CBC, bytes(iv))
decrypted = aes.decrypt(bytes(data[iv_bit_count:]))
return unpad_after_decryption(decrypted)
def generate_random_key(length=32, chars=None):
chars = chars if chars else (string.ascii_uppercase +
string.ascii_lowercase + string.digits)
return ''.join(random.choice(chars) for _ in range(length))