encryption: unified and rewrote encryption modules to be consistent no matter what algo is used.

- few python3 fixes as well

rhodecode/lib/enc_utils.py

@@ -0,0 +1,48 b''
+from rhodecode.lib.str_utils import safe_bytes
+from rhodecode.lib.encrypt import encrypt_data, validate_and_decrypt_data
+from rhodecode.lib.encrypt2 import Encryptor
+
+ALLOWED_ALGOS = ['aes', 'fernet']
+
+
+def get_default_algo():
+    import rhodecode
+    return rhodecode.CONFIG.get('rhodecode.encrypted_values.algorithm') or 'aes'
+
+
+def encrypt_value(value: bytes, enc_key: bytes, algo: str = ''):
+    if not algo:
+        # not explicit algo, just use what's set by config
+        algo = get_default_algo()
+    if algo not in ALLOWED_ALGOS:
+        ValueError(f'Bad encryption algorithm, should be {ALLOWED_ALGOS}, got: {algo}')
+
+    enc_key = safe_bytes(enc_key)
+    value = safe_bytes(value)
+
+    if algo == 'aes':
+        return encrypt_data(value, enc_key=enc_key)
+    if algo == 'fernet':
+        return Encryptor(enc_key).encrypt(value)
+
+    return value
+
+
+def decrypt_value(value: bytes, enc_key: bytes, algo: str = '', strict_mode: bool = False):
+
+    if not algo:
+        # not explicit algo, just use what's set by config
+        algo = get_default_algo()
+    if algo not in ALLOWED_ALGOS:
+        ValueError(f'Bad encryption algorithm, should be {ALLOWED_ALGOS}, got: {algo}')
+
+    enc_key = safe_bytes(enc_key)
+    value = safe_bytes(value)
+    safe = not strict_mode
+
+    if algo == 'aes':
+        return validate_and_decrypt_data(value, enc_key, safe=safe)
+    if algo == 'fernet':
+        return Encryptor(enc_key).decrypt(value, safe=safe)
+
+    return value

rhodecode/lib/encrypt.py

@@ -1,138 +1,152 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2014-2020 RhodeCode GmbH
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License, version 3
 # (only), as published by the Free Software Foundation.
 #
 # 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 Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
 
 """
 Generic encryption library for RhodeCode
 """
 
 import base64
+import logging
 
 from Crypto.Cipher import AES
 from Crypto import Random
 from Crypto.Hash import HMAC, SHA256
 
-from rhodecode.lib.str_utils import safe_bytes
-
-
-class SignatureVerificationError(Exception):
-    pass
+from rhodecode.lib.str_utils import safe_bytes, safe_str
+from rhodecode.lib.exceptions import signature_verification_error
 
 
 class InvalidDecryptedValue(str):
 
     def __new__(cls, content):
         """
         This will generate something like this::
             <InvalidDecryptedValue(QkWusFgLJXR6m42v...)>
         And represent a safe indicator that encryption key is broken
         """
         content = '<{}({}...)>'.format(cls.__name__, content[:16])
         return str.__new__(cls, content)
 
+KEY_FORMAT = b'enc$aes_hmac${1}'
+
 
 class AESCipher(object):
-    def __init__(self, key, hmac=False, strict_verification=True):
+
+    def __init__(self, key: bytes, hmac=False, strict_verification=True):
+
         if not key:
             raise ValueError('passed key variable is empty')
         self.strict_verification = strict_verification
         self.block_size = 32
         self.hmac_size = 32
         self.hmac = hmac
 
         self.key = SHA256.new(safe_bytes(key)).digest()
         self.hmac_key = SHA256.new(self.key).digest()
 
     def verify_hmac_signature(self, raw_data):
         org_hmac_signature = raw_data[-self.hmac_size:]
         data_without_sig = raw_data[:-self.hmac_size]
         recomputed_hmac = HMAC.new(
             self.hmac_key, data_without_sig, digestmod=SHA256).digest()
         return org_hmac_signature == recomputed_hmac
 
-    def encrypt(self, raw):
+    def encrypt(self, raw: bytes):
         raw = self._pad(raw)
         iv = Random.new().read(AES.block_size)
         cipher = AES.new(self.key, AES.MODE_CBC, iv)
         enc_value = cipher.encrypt(raw)
 
-        hmac_signature = ''
+        hmac_signature = b''
         if self.hmac:
             # compute hmac+sha256 on iv + enc text, we use
             # encrypt then mac method to create the signature
             hmac_signature = HMAC.new(
                 self.hmac_key, iv + enc_value, digestmod=SHA256).digest()
 
         return base64.b64encode(iv + enc_value + hmac_signature)
 
-    def decrypt(self, enc):
+    def decrypt(self, enc, safe=True) -> bytes | InvalidDecryptedValue:
         enc_org = enc
-        enc = base64.b64decode(enc)
+        try:
+            enc = base64.b64decode(enc)
+        except Exception:
+            logging.exception('Failed Base64 decode')
+            raise signature_verification_error('Failed Base64 decode')
 
         if self.hmac and len(enc) > self.hmac_size:
             if self.verify_hmac_signature(enc):
                 # cut off the HMAC verification digest
                 enc = enc[:-self.hmac_size]
             else:
-                if self.strict_verification:
-                    raise SignatureVerificationError(
-                        "Encryption signature verification failed. "
-                        "Please check your secret key, and/or encrypted value. "
-                        "Secret key is stored as "
-                        "`rhodecode.encrypted_values.secret` or "
-                        "`beaker.session.secret` inside .ini file")
 
-                return InvalidDecryptedValue(enc_org)
+                decrypt_fail = InvalidDecryptedValue(safe_str(enc_org))
+                if safe:
+                    return decrypt_fail
+                raise signature_verification_error(decrypt_fail)
 
         iv = enc[:AES.block_size]
         cipher = AES.new(self.key, AES.MODE_CBC, iv)
         return self._unpad(cipher.decrypt(enc[AES.block_size:]))
 
     def _pad(self, s):
-        return (s + (self.block_size - len(s) % self.block_size)
-                * chr(self.block_size - len(s) % self.block_size))
+        block_pad = (self.block_size - len(s) % self.block_size)
+        return s + block_pad * safe_bytes(chr(block_pad))
 
     @staticmethod
     def _unpad(s):
         return s[:-ord(s[len(s)-1:])]
 
 
-def validate_and_get_enc_data(enc_data, enc_key, enc_strict_mode):
+def validate_and_decrypt_data(enc_data, enc_key, enc_strict_mode=False, safe=True):
+    enc_data = safe_str(enc_data)
+
     parts = enc_data.split('$', 3)
-    if not len(parts) == 3:
-        # probably not encrypted values
+    if len(parts) != 3:
+        raise ValueError(f'Encrypted Data has invalid format, expected {KEY_FORMAT}, got {parts}')
+
+    enc_type = parts[1]
+    enc_data_part = parts[2]
+
+    if parts[0] != 'enc':
+        # parts ok but without our header ?
         return enc_data
-    else:
-        if parts[0] != 'enc':
-            # parts ok but without our header ?
-            return enc_data
 
-        # at that stage we know it's our encryption
-        if parts[1] == 'aes':
-            decrypted_data = AESCipher(enc_key).decrypt(parts[2])
-        elif parts[1] == 'aes_hmac':
-            decrypted_data = AESCipher(
-                enc_key, hmac=True,
-                strict_verification=enc_strict_mode).decrypt(parts[2])
-        else:
-            raise ValueError(
-                'Encryption type part is wrong, must be `aes` '
-                'or `aes_hmac`, got `%s` instead' % (parts[1]))
-        return decrypted_data
+    # at that stage we know it's our encryption
+    if enc_type == 'aes':
+        decrypted_data = AESCipher(enc_key).decrypt(enc_data_part, safe=safe)
+    elif enc_type == 'aes_hmac':
+        decrypted_data = AESCipher(
+            enc_key, hmac=True,
+            strict_verification=enc_strict_mode).decrypt(enc_data_part, safe=safe)
+
+    else:
+        raise ValueError(
+            f'Encryption type part is wrong, must be `aes` '
+            f'or `aes_hmac`, got `{enc_type}` instead')
+
+    return decrypted_data
+
+
+def encrypt_data(data, enc_key: bytes):
+    enc_key = safe_bytes(enc_key)
+    enc_value = AESCipher(enc_key, hmac=True).encrypt(safe_bytes(data))
+    return KEY_FORMAT.replace(b'{1}', enc_value)

rhodecode/lib/encrypt2.py

@@ -1,69 +1,84 b''
 import os
 import base64
 from cryptography.fernet import Fernet, InvalidToken
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives import hashes
 from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
 
+from rhodecode.lib.str_utils import safe_str
+from rhodecode.lib.exceptions import signature_verification_error
+
+
+class InvalidDecryptedValue(str):
+
+    def __new__(cls, content):
+        """
+        This will generate something like this::
+            <InvalidDecryptedValue(QkWusFgLJXR6m42v...)>
+        And represent a safe indicator that encryption key is broken
+        """
+        content = '<{}({}...)>'.format(cls.__name__, content[:16])
+        return str.__new__(cls, content)
+
 
 class Encryptor(object):
-    key_format = 'enc2$salt:{}$data:{}'
+    key_format = b'enc2$salt:{1}$data:{2}'
     pref_len = 5  # salt:, data:
 
-    def __init__(self, enc_key):
+    def __init__(self, enc_key: bytes):
         self.enc_key = enc_key
 
     def b64_encode(self, data):
         return base64.urlsafe_b64encode(data)
 
     def b64_decode(self, data):
         return base64.urlsafe_b64decode(data)
 
     def get_encryptor(self, salt):
         """
         Uses Fernet as encryptor with HMAC signature
         :param salt: random salt used for encrypting the data
         """
         kdf = PBKDF2HMAC(
             algorithm=hashes.SHA512(),
             length=32,
             salt=salt,
             iterations=100000,
             backend=default_backend()
         )
         key = self.b64_encode(kdf.derive(self.enc_key))
         return Fernet(key)
 
     def _get_parts(self, enc_data):
-        parts = enc_data.split('$', 3)
+        parts = enc_data.split(b'$', 3)
         if len(parts) != 3:
-            raise ValueError('Encrypted Data has invalid format, expected {}'.format(self.key_format))
+            raise ValueError(f'Encrypted Data has invalid format, expected {self.key_format}, got {parts}')
         prefix, salt, enc_data = parts
 
         try:
             salt = self.b64_decode(salt[self.pref_len:])
         except TypeError:
             # bad base64
             raise ValueError('Encrypted Data salt invalid format, expected base64 format')
 
         enc_data = enc_data[self.pref_len:]
         return prefix, salt, enc_data
 
-    def encrypt(self, data):
+    def encrypt(self, data) -> bytes:
         salt = os.urandom(64)
         encryptor = self.get_encryptor(salt)
         enc_data = encryptor.encrypt(data)
-        return self.key_format.format(self.b64_encode(salt), enc_data)
+        return self.key_format.replace(b'{1}', self.b64_encode(salt)).replace(b'{2}', enc_data)
 
-    def decrypt(self, data, safe=True):
+    def decrypt(self, data, safe=True) -> bytes | InvalidDecryptedValue:
         parts = self._get_parts(data)
         salt = parts[1]
         enc_data = parts[2]
         encryptor = self.get_encryptor(salt)
         try:
             return encryptor.decrypt(enc_data)
         except (InvalidToken,):
+            decrypt_fail = InvalidDecryptedValue(safe_str(data))
             if safe:
-                return ''
-            else:
-                raise
+                return decrypt_fail
+            raise signature_verification_error(decrypt_fail)