+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# 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.
+
+# XOR oriented cryptographic ciphers and utilities.
+module xor_ciphers
+
+redef class Bytes
+ # Returns `self` xored with `key`
+ #
+ # The key is cycled through until the `self` has been completely xored.
+ #
+ # assert "goodmorning".to_bytes.xorcipher(" ".to_bytes) == "GOODMORNING".bytes
+ fun xorcipher(key: Bytes): Bytes do
+ var xored = new Bytes.with_capacity(self.length)
+
+ for i in self.length.times do
+ xored.add(self[i] ^ key[i % key.length])
+ end
+
+ return xored
+ end
+end