From 135d0b5dd111d40632e2cd5be8f5315684b45fc6 Mon Sep 17 00:00:00 2001 From: Christian Heimes Date: Sat, 25 Feb 2017 11:06:04 +0100 Subject: [PATCH] Finish port to PyCA cryptography * add missing default_backend * unpad encrypted data * use cryptography's hashes and HMAC construct * remove hard dependency on python-nss from setup.py Signed-off-by: Christian Heimes Reviewed-By: Stanislav Laznicka --- ipaserver/install/ipa_otptoken_import.py | 92 +++++++++++++++--------- ipaserver/setup.py | 1 - ipatests/setup.py | 3 +- 3 files changed, 60 insertions(+), 36 deletions(-) diff --git a/ipaserver/install/ipa_otptoken_import.py b/ipaserver/install/ipa_otptoken_import.py index 3b2e52ab2..2580e2cfc 100644 --- a/ipaserver/install/ipa_otptoken_import.py +++ b/ipaserver/install/ipa_otptoken_import.py @@ -20,20 +20,18 @@ import abc import base64 import datetime -import hashlib -import hmac import os import uuid -import struct from lxml import etree import dateutil.parser import dateutil.tz import gssapi import six -from six.moves import xrange -from cryptography.hazmat.primitives import hashes +from cryptography.exceptions import InvalidSignature +from cryptography.hazmat.primitives import hashes, hmac +from cryptography.hazmat.primitives.padding import PKCS7 from cryptography.hazmat.primitives.kdf import pbkdf2 from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes from cryptography.hazmat.backends import default_backend @@ -111,25 +109,32 @@ def convertHMACType(value): "Converts HMAC URI to hashlib object." return { - "http://www.w3.org/2000/09/xmldsig#hmac-sha1": hashlib.sha1, - "http://www.w3.org/2001/04/xmldsig-more#hmac-sha224": hashlib.sha224, - "http://www.w3.org/2001/04/xmldsig-more#hmac-sha256": hashlib.sha256, - "http://www.w3.org/2001/04/xmldsig-more#hmac-sha384": hashlib.sha384, - "http://www.w3.org/2001/04/xmldsig-more#hmac-sha512": hashlib.sha512, - }.get(value.lower(), hashlib.sha1) + "http://www.w3.org/2000/09/xmldsig#hmac-sha1": hashes.SHA1, + "http://www.w3.org/2001/04/xmldsig-more#hmac-sha224": hashes.SHA224, + "http://www.w3.org/2001/04/xmldsig-more#hmac-sha256": hashes.SHA256, + "http://www.w3.org/2001/04/xmldsig-more#hmac-sha384": hashes.SHA384, + "http://www.w3.org/2001/04/xmldsig-more#hmac-sha512": hashes.SHA512, + }.get(value.lower(), hashes.SHA1) def convertAlgorithm(value): "Converts encryption URI to (mech, ivlen)." return { - "http://www.w3.org/2001/04/xmlenc#aes128-cbc": (algorithms.AES, modes.CBC, 128), - "http://www.w3.org/2001/04/xmlenc#aes192-cbc": (algorithms.AES, modes.CBC, 192), - "http://www.w3.org/2001/04/xmlenc#aes256-cbc": (algorithms.AES, modes.CBC, 256), - "http://www.w3.org/2001/04/xmlenc#tripledes-cbc": (algorithms.TripleDES, modes.CBC, 64), - "http://www.w3.org/2001/04/xmldsig-more#camellia128": (algorithms.Camellia, modes.CBC, 128), - "http://www.w3.org/2001/04/xmldsig-more#camellia192": (algorithms.Camellia, modes.CBC, 192), - "http://www.w3.org/2001/04/xmldsig-more#camellia256": (algorithms.Camellia, modes.CBC, 256), + "http://www.w3.org/2001/04/xmlenc#aes128-cbc": ( + algorithms.AES, modes.CBC, 128), + "http://www.w3.org/2001/04/xmlenc#aes192-cbc": ( + algorithms.AES, modes.CBC, 192), + "http://www.w3.org/2001/04/xmlenc#aes256-cbc": ( + algorithms.AES, modes.CBC, 256), + "http://www.w3.org/2001/04/xmlenc#tripledes-cbc": ( + algorithms.TripleDES, modes.CBC, 64), + "http://www.w3.org/2001/04/xmldsig-more#camellia128": ( + algorithms.Camellia, modes.CBC, 128), + "http://www.w3.org/2001/04/xmldsig-more#camellia192": ( + algorithms.Camellia, modes.CBC, 192), + "http://www.w3.org/2001/04/xmldsig-more#camellia256": ( + algorithms.Camellia, modes.CBC, 256), # TODO: add support for these formats. # "http://www.w3.org/2001/04/xmlenc#kw-aes128": "kw-aes128", @@ -174,10 +179,14 @@ class PBKDF2KeyDerivation(XMLKeyDerivation): if params is None: raise ValueError("XML file is missing PBKDF2 parameters!") - salt = fetch(params, "./xenc11:Salt/xenc11:Specified/text()", base64.b64decode) - itrs = fetch(params, "./xenc11:IterationCount/text()", int) - klen = fetch(params, "./xenc11:KeyLength/text()", int) - hmod = fetch(params, "./xenc11:PRF/@Algorithm", convertHMACType, hashlib.sha1) + salt = fetch( + params, "./xenc11:Salt/xenc11:Specified/text()", base64.b64decode) + itrs = fetch( + params, "./xenc11:IterationCount/text()", int) + klen = fetch( + params, "./xenc11:KeyLength/text()", int) + hmod = fetch( + params, "./xenc11:PRF/@Algorithm", convertHMACType, hashes.SHA1) if salt is None: raise ValueError("XML file is missing PBKDF2 salt!") @@ -189,10 +198,11 @@ class PBKDF2KeyDerivation(XMLKeyDerivation): raise ValueError("XML file is missing PBKDF2 key length!") self.kdf = pbkdf2.PBKDF2HMAC( - algorithm=hmod, + algorithm=hmod(), length=klen, salt=salt, - iterations=itrs + iterations=itrs, + backend=default_backend() ) def derive(self, masterkey): @@ -217,8 +227,13 @@ class XMLDecryptor(object): self.__hmac = hmac def __call__(self, element, mac=None): - (algo, mode, klen) = fetch(element, "./xenc:EncryptionMethod/@Algorithm", convertAlgorithm) - data = fetch(element, "./xenc:CipherData/xenc:CipherValue/text()", base64.b64decode) + algo, mode, klen = fetch( + element, "./xenc:EncryptionMethod/@Algorithm", convertAlgorithm) + data = fetch( + element, + "./xenc:CipherData/xenc:CipherValue/text()", + base64.b64decode + ) # Make sure the key is the right length. if len(self.__key) * 8 != klen: @@ -228,17 +243,24 @@ class XMLDecryptor(object): if mac: tmp = self.__hmac.copy() tmp.update(data) - if tmp.digest() != mac: - raise ValidationError("MAC validation failed!") + try: + tmp.verify(mac) + except InvalidSignature as e: + raise ValidationError("MAC validation failed!", e) - iv = data[:algo.block_size / 8] + iv = data[:algo.block_size // 8] data = data[len(iv):] - cipher = Cipher(algo(self.__key), mode(iv)) + algorithm = algo(self.__key) + cipher = Cipher(algorithm, mode(iv), default_backend()) decryptor = cipher.decryptor() + padded = decryptor.update(data) + padded += decryptor.finalize() + + unpadder = PKCS7(algorithm.block_size).unpadder() + out = unpadder.update(padded) + out += unpadder.finalize() - out = decryptor.update(data) - out += decryptor.finalize() return out @@ -441,7 +463,11 @@ class PSKCDocument(object): # Load the decryptor. self.__decryptor = XMLDecryptor(key) if self.__mkey is not None and self.__algo is not None: - tmp = hmac.HMAC(self.__decryptor(self.__mkey), digestmod=self.__algo) + tmp = hmac.HMAC( + self.__decryptor(self.__mkey), + self.__algo(), + backend=default_backend() + ) self.__decryptor = XMLDecryptor(key, tmp) def getKeyPackages(self): diff --git a/ipaserver/setup.py b/ipaserver/setup.py index 95ba5ebfc..d3c735c0f 100755 --- a/ipaserver/setup.py +++ b/ipaserver/setup.py @@ -58,7 +58,6 @@ if __name__ == '__main__': "netaddr", "pyasn1", "pyldap", - "python-nss", "six", # not available on PyPI # "python-libipa_hbac", diff --git a/ipatests/setup.py b/ipatests/setup.py index e46e922fd..46d51ff1c 100644 --- a/ipatests/setup.py +++ b/ipatests/setup.py @@ -71,12 +71,11 @@ if __name__ == '__main__': "pyldap", "pytest", "pytest_multihost", - "python-nss", "six", ], extras_require={ "integration": ["dbus-python", "pyyaml", "ipaserver"], - "ipaserver": ["ipaserver"], + "ipaserver": ["ipaserver", "python-nss"], "webui": ["selenium", "pyyaml", "ipaserver"], "xmlrpc": ["ipaserver"], }