encryption: added new backend using cryptography + Fernet encryption.

- This would soon replace the old deprecated one based on pycrypto
- We need a migration for the encryption data

rhodecode/lib/encrypt2.py

@@ -0,0 +1,69 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
+
+
+class Encryptor(object):
+    key_format = 'enc2$salt:{}$data:{}'
+    pref_len = 5  # salt:, data:
+
+    def __init__(self, enc_key):
+        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)
+        if len(parts) != 3:
+            raise ValueError('Encrypted Data has invalid format, expected {}'.format(self.key_format))
+        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):
+        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)
+
+    def decrypt(self, data, safe=True):
+        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,):
+            if safe:
+                return ''
+            else:
+                raise

configs/development.ini

@@ -133,6 +133,11 b' rhodecode.api.url = /_admin/api'
 ## `SignatureVerificationError` in case of wrong key, or damaged encryption data.
 #rhodecode.encrypted_values.strict = false
 
+## Pick algorithm for encryption. Either fernet (more secure) or aes (default)
+## fernet is safer, and we strongly recommend switching to it.
+## Due to backward compatibility aes is used as default.
+#rhodecode.encrypted_values.algorithm = fernet
+
 ## return gzipped responses from RhodeCode (static files/application)
 gzip_responses = false
 

configs/production.ini

@@ -108,6 +108,11 b' use = egg:rhodecode-enterprise-ce'
 ## `SignatureVerificationError` in case of wrong key, or damaged encryption data.
 #rhodecode.encrypted_values.strict = false
 
+## Pick algorithm for encryption. Either fernet (more secure) or aes (default)
+## fernet is safer, and we strongly recommend switching to it.
+## Due to backward compatibility aes is used as default.
+#rhodecode.encrypted_values.algorithm = fernet
+
 ## return gzipped responses from RhodeCode (static files/application)
 gzip_responses = false
 

rhodecode/lib/encrypt.py

@@ -111,4 +111,28 b' class AESCipher(object):'
 
     @staticmethod
     def _unpad(s):
-        return s[:-ord(s[len(s)-1:])]
  No newline at end of file
+        return s[:-ord(s[len(s)-1:])]
+
+
+def validate_and_get_enc_data(enc_data, enc_key, enc_strict_mode):
+    parts = enc_data.split('$', 3)
+    if not len(parts) == 3:
+        # probably not encrypted values
+        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

rhodecode/model/db.py

@@ -62,8 +62,8 b' from rhodecode.lib.jsonalchemy import Mu'
     JsonRaw
 from rhodecode.lib.ext_json import json
 from rhodecode.lib.caching_query import FromCache
-from rhodecode.lib.encrypt import AESCipher
-
+from rhodecode.lib.encrypt import AESCipher, validate_and_get_enc_data
+from rhodecode.lib.encrypt2 import Encryptor
 from rhodecode.model.meta import Base, Session
 
 URL_SEP = '/'
@@ -159,43 +159,45 b' class EncryptedTextValue(TypeDecorator):'
     impl = Text
 
     def process_bind_param(self, value, dialect):
-        if not value:
-            return value
-        if value.startswith('enc$aes$') or value.startswith('enc$aes_hmac$'):
-            # protect against double encrypting if someone manually starts
-            # doing
-            raise ValueError('value needs to be in unencrypted format, ie. '
-                             'not starting with enc$aes')
-        return 'enc$aes_hmac$%s' % AESCipher(
-            ENCRYPTION_KEY, hmac=True).encrypt(value)
-
-    def process_result_value(self, value, dialect):
+        """
+        Setter for storing value
+        """
         import rhodecode
-
         if not value:
             return value
 
-        parts = value.split('$', 3)
-        if not len(parts) == 3:
-            # probably not encrypted values
-            return value
+        # protect against double encrypting if values is already encrypted
+        if value.startswith('enc$aes$') \
+                or value.startswith('enc$aes_hmac$') \
+                or value.startswith('enc2$'):
+            raise ValueError('value needs to be in unencrypted format, '
+                             'ie. not starting with enc$ or enc2$')
+
+        algo = rhodecode.CONFIG.get('rhodecode.encrypted_values.algorithm') or 'aes'
+        if algo == 'aes':
+            return 'enc$aes_hmac$%s' % AESCipher(ENCRYPTION_KEY, hmac=True).encrypt(value)
+        elif algo == 'fernet':
+            return Encryptor(ENCRYPTION_KEY).encrypt(value)
         else:
-            if parts[0] != 'enc':
-                # parts ok but without our header ?
+            ValueError('Bad encryption algorithm, should be fernet or aes, got: {}'.format(algo))
+
+    def process_result_value(self, value, dialect):
+        """
+        Getter for retrieving value
+        """
+
+        import rhodecode
+        if not value:
                 return value
-            enc_strict_mode = str2bool(rhodecode.CONFIG.get(
-                'rhodecode.encrypted_values.strict') or True)
-            # at that stage we know it's our encryption
-            if parts[1] == 'aes':
-                decrypted_data = AESCipher(ENCRYPTION_KEY).decrypt(parts[2])
-            elif parts[1] == 'aes_hmac':
-                decrypted_data = AESCipher(
-                    ENCRYPTION_KEY, hmac=True,
-                    strict_verification=enc_strict_mode).decrypt(parts[2])
+
+        algo = rhodecode.CONFIG.get('rhodecode.encrypted_values.algorithm') or 'aes'
+        enc_strict_mode = str2bool(rhodecode.CONFIG.get('rhodecode.encrypted_values.strict') or True)
+        if algo == 'aes':
+            decrypted_data = validate_and_get_enc_data(value, ENCRYPTION_KEY, enc_strict_mode)
+        elif algo == 'fernet':
+            return Encryptor(ENCRYPTION_KEY).decrypt(value)
             else:
-                raise ValueError(
-                    'Encryption type part is wrong, must be `aes` '
-                    'or `aes_hmac`, got `%s` instead' % (parts[1]))
+            ValueError('Bad encryption algorithm, should be fernet or aes, got: {}'.format(algo))
             return decrypted_data
 
 

rhodecode/tests/lib/test_encrypt.py

@@ -22,6 +22,7 b' import pytest'
 
 from rhodecode.lib.encrypt import (
     AESCipher, SignatureVerificationError, InvalidDecryptedValue)
+from rhodecode.lib.encrypt2 import (Encryptor, InvalidToken)
 
 
 class TestEncryptModule(object):
@@ -74,3 +75,59 b' class TestEncryptModule(object):'
         assert isinstance(AESCipher(
             'differentsecret', hmac=True, strict_verification=False
         ).decrypt(enc), InvalidDecryptedValue)
+
+
+class TestEncryptModule2(object):
+
+    @pytest.mark.parametrize(
+        "key, text",
+        [
+            ('a', 'short'),
+            ('a'*64, 'too long(trimmed to 32)'),
+            ('a'*32, 'just enough'),
+            ('ąćęćę', 'non asci'),
+            ('$asa$asa', 'special $ used'),
+        ]
+    )
+    def test_encryption(self, key, text):
+        enc = Encryptor(key).encrypt(text)
+        assert Encryptor(key).decrypt(enc) == text
+
+    def test_encryption_with_bad_key(self):
+        key = 'secretstring'
+        text = 'ihatemysql'
+        enc = Encryptor(key).encrypt(text)
+
+        assert Encryptor('differentsecret').decrypt(enc) == ''
+
+    def test_encryption_with_bad_key_raises(self):
+        key = 'secretstring'
+        text = 'ihatemysql'
+        enc = Encryptor(key).encrypt(text)
+
+        with pytest.raises(InvalidToken) as e:
+            Encryptor('differentsecret').decrypt(enc, safe=False)
+
+        assert 'InvalidToken' in str(e)
+
+    def test_encryption_with_bad_format_data(self):
+        key = 'secret'
+        text = 'ihatemysql'
+        enc = Encryptor(key).encrypt(text)
+        enc = '$xyz' + enc[3:]
+
+        with pytest.raises(ValueError) as e:
+            Encryptor(key).decrypt(enc, safe=False)
+
+        assert 'Encrypted Data has invalid format' in str(e)
+
+    def test_encryption_with_bad_data(self):
+        key = 'secret'
+        text = 'ihatemysql'
+        enc = Encryptor(key).encrypt(text)
+        enc = enc[:-5]
+
+        with pytest.raises(InvalidToken) as e:
+            Encryptor(key).decrypt(enc, safe=False)
+
+        assert 'InvalidToken' in str(e)