Add XOR enc

Signed-off-by: 0x4248 <60709927+0x4248@users.noreply.github.com>

c/XORenc/CMakeLists.txt

@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-3.0
+# XORenc
+#
+# CMakeLists.txt
+#
+# COPYRIGHT NOTICE
+# Copyright (C) 2024 0x4248 and contributors
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the license is not changed.
+# 
+# This software is free and open source. Licensed under the GNU general
+# public license version 3.0 as published by the Free Software Foundation.
+
+project(XORenc)
+
+add_executable(main main.c)

c/XORenc/main.c

@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-3.0
+ * XORenc
+ *
+ * main.c
+ *
+ * COPYRIGHT NOTICE
+ * Copyright (C) 2024 0x4248 and contributors
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the license is not changed.
+ * 
+ * This software is free and open source. Licensed under the GNU general
+ * public license version 3.0 as published by the Free Software Foundation.
+*/
+
+#include <stdio.h>
+
+char *encode(char *str, int *key){
+	/**
+	 * Loop over each item in input string (str) and XOR it with the key using
+	 * the modulo operator to get the correct index of the key.
+	 * 
+	 * If we hit \0 we are at the end of the string and we can stop.
+	 */
+	for(int i = 0; str[i] != '\0'; i++){
+		str[i] = str[i] ^ key[i % 4];
+	}
+	return str;
+}
+
+int main(){
+	char str[] = "Hello, World!";
+	int key[] = {7, 4, 5, 3};
+
+
+	/* Encrypt */
+	encode(str, key);
+	printf("%s\n", str);
+
+
+	/* Decrypt */
+	encode(str, key);
+	printf("%s\n", str);
+	return 0;
+}

scraps.mk

@@ -27,4 +27,5 @@ MK-S += fortran/filetest/Makefile
 MK-S += !c/writing_raw
 MK-S += !c/http_server
 MK-S += @c/tiny/build.sh
-MK-S += !c/factorial
+MK-S += !c/factorial
+MK-S += !c/XORenc