Added multi-backend abstraction for AES-128 CBC primitive

This commit is contained in:
Mark Qvist 2022-06-08 12:21:50 +02:00
parent 0b1e7df31a
commit d1a461a2b3
4 changed files with 131 additions and 6 deletions

55
RNS/Cryptography/AES.py Normal file
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@ -0,0 +1,55 @@
# MIT License
#
# Copyright (c) 2022 Mark Qvist / unsigned.io
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
PROVIDER_INTERNAL = 0x01
PROVIDER_PYCA = 0x02
provider = PROVIDER_PYCA
if provider == PROVIDER_INTERNAL:
pass
elif provider == PROVIDER_PYCA:
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
class AES_128_CBC:
@staticmethod
def encrypt(plaintext, key, iv):
if provider == PROVIDER_INTERNAL:
pass
elif provider == PROVIDER_PYCA:
cipher = Cipher(algorithms.AES(key), modes.CBC(iv))
encryptor = cipher.encryptor()
ciphertext = encryptor.update(plaintext) + encryptor.finalize()
return ciphertext
@staticmethod
def decrypt(ciphertext, key, iv):
if provider == PROVIDER_INTERNAL:
pass
elif provider == PROVIDER_PYCA:
cipher = Cipher(algorithms.AES(key), modes.CBC(iv))
decryptor = cipher.decryptor()
plaintext = decryptor.update(ciphertext) + decryptor.finalize()
return plaintext

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@ -1,3 +1,26 @@
# MIT License
#
# Copyright (c) 2022 Mark Qvist / unsigned.io
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import os
import time
from RNS.Cryptography import HMAC
@ -10,9 +33,12 @@ class Fernet():
def generate_key():
return os.urandom(32)
def __init__(key = None):
if not len(key) != 32:
raise ValueError("Fernet key must be 256 bits (32 bytes) long")
def __init__(self, key = None):
if key == None:
raise ValueError("Fernet key cannot be None")
if len(key) != 32:
raise ValueError("Fernet key must be 32 bytes, not "+str(len(key)))
self._signing_key = key[:16]
self._encryption_key = key[16:]
@ -33,7 +59,7 @@ class Fernet():
def encrypt(self, data = None):
iv = os.urandom(16)
current_time = time.time()
current_time = int(time.time())
if not isinstance(data, bytes):
raise TypeError("Fernet token plaintext input must be bytes")
@ -57,13 +83,13 @@ class Fernet():
raise ValueError("Fernet token HMAC was invalid")
iv = token[9:25]
ciphertext = [25:-32]
ciphertext = token[25:-32]
try:
plaintext = PKCS7.unpad(
AES_128_CBC.decrypt(
self._encryption_key,
ciphertext,
self._encryption_key,
iv,
)
)

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@ -1,3 +1,25 @@
# MIT License
#
# Copyright (c) 2022 Mark Qvist / unsigned.io
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import hashlib
from math import ceil
from RNS.Cryptography import HMAC

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@ -1,3 +1,25 @@
# MIT License
#
# Copyright (c) 2022 Mark Qvist / unsigned.io
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
class PKCS7:
BLOCKSIZE = 16