feat: add eodag.utils.security containing crypto classes (#60)

Author: CGuichard

eodag/utils/security.py

@@ -0,0 +1,120 @@
+# -*- coding: utf-8 -*-
+# Copyright 2021, CS GROUP - France, https://www.csgroup.eu/
+#
+# This file is part of EODAG project
+#     https://www.github.com/CS-SI/EODAG
+#
+# 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.
+
+from cryptography.fernet import Fernet
+
+
+class CryptoKey:
+    """Encapsulate a key implementation."""
+
+    def __init__(self, strkey=None, byteskey=None):
+        if strkey:
+            self._value = strkey.encode()
+        elif byteskey:
+            self._value = byteskey
+        else:
+            self._value = Fernet.generate_key()
+
+    @staticmethod
+    def from_str(strkey):
+        """Build a :class:`~eodag.utils.security.CryptoKey` object from its string representation
+
+        :param strkey: The key as str
+        :type strkey: str
+        :returns: The :class:`~eodag.utils.security.CryptoKey` built from `strkey`
+        :rtype: :class:`~eodag.utils.security.CryptoKey`
+        """
+        return CryptoKey(strkey=strkey)
+
+    @staticmethod
+    def from_bytes(byteskey):
+        """Build a :class:`~eodag.utils.security.CryptoKey` object from its bytes representation
+
+        :param byteskey: The key as bytes
+        :type byteskey: bytes
+        :returns: The :class:`~eodag.utils.security.CryptoKey` built from `byteskey`
+        :rtype: :class:`~eodag.utils.security.CryptoKey`
+        """
+        return CryptoKey(byteskey=byteskey)
+
+    @property
+    def value(self):
+        """Read-only property on the value of the key"""
+        return self._value
+
+    def as_str(self):
+        """Return str representation of the key"""
+        return self.value.decode()
+
+
+class Crypto:
+    """Class used for symmetric encryption of text, using a key."""
+
+    def __init__(self, key=None):
+        self._key = key if key is not None else CryptoKey()
+        self._impl = Fernet(self._key.value)
+
+    @staticmethod
+    def from_key(key):
+        """Build a :class:`~eodag.utils.security.Crypto` object with a :class:`~eodag.utils.security.CryptoKey`
+
+        :param key: The key as str
+        :type key: :class:`~eodag.utils.security.CryptoKey`
+        :returns: The :class:`~eodag.utils.security.Crypto` object built
+                  with a :class:`~eodag.utils.security.CryptoKey`
+        :rtype: :class:`~eodag.utils.security.Crypto`
+        """
+        return Crypto(key=key)
+
+    @staticmethod
+    def from_strkey(strkey):
+        """Build a :class:`~eodag.utils.security.Crypto` object with a key str
+
+        :param strkey: The key as str
+        :type strkey: str
+        :returns: The :class:`~eodag.utils.security.Crypto` object built
+                  with a :class:`~eodag.utils.security.CryptoKey`, itself built from `strkey`
+        :rtype: :class:`~eodag.utils.security.Crypto`
+        """
+        key = CryptoKey.from_str(strkey=strkey)
+        return Crypto.from_key(key=key)
+
+    @property
+    def key(self):
+        """Read-only property on the key used by the :class:`~eodag.utils.security.Crypto` object"""
+        return self._key
+
+    def encrypt(self, text):
+        """Encrypt a text
+
+        :param text: The text to encrypt
+        :type text: str
+        :returns: The encrypted text
+        :rtype: str
+        """
+        return self._impl.encrypt(text.encode()).decode()
+
+    def decrypt(self, encrypted_text):
+        """Decrypt an encrypted text
+
+        :param encrypted_text: The encrypted text
+        :type encrypted_text: str
+        :returns: The decrypted text
+        :rtype: str
+        """
+        return self._impl.decrypt(encrypted_text.encode()).decode()