XOR Support (#47)

* build: add dependency on ext-gmp

* feat: add ability to xor strings

* test: assert xor works

* docs: add "app:xor-string"

tool/README.md

@@ -11,3 +11,4 @@ _Liber Primus decoding._
 * `php cicada app:to-runic` - Converts a string to runic.
 * `php cicada app:translate` - Translation from runic to English using Gematria values.
 * `php cicada app:vigenere` - Decodes a Vigenere cipher using a key and skip indexes from Gematria values.
+* `php cicada app:xor-string` - XORs a string with a key.

tool/app/Commands/XorString.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Commands;
+
+use LaravelZero\Framework\Commands\Command;
+
+class XorString extends Command
+{
+    protected $signature = 'app:xor-string';
+
+    protected $description = 'XOR String with a variety of files from previous puzzles.';
+
+    public function handle(): int
+    {
+        $string = $this->ask('Enter a string to XOR');
+        $key = $this->ask('Enter the key.');
+
+        $xor1 = gmp_init($string, 16);
+        $xor2 = gmp_init($key, 16);
+
+        $xor = gmp_xor($xor1, $xor2);
+        $output = pack('H*', gmp_strval($xor, 16));
+
+        $this->output->write('XOR: '.$output.PHP_EOL);
+
+        return self::SUCCESS;
+    }
+}

tool/composer.json

@@ -5,6 +5,7 @@
     "license": "MIT",
     "require": {
         "php": "^8.1",
+        "ext-gmp": "*",
         "drupol/phpermutations": "^1.4",
         "laravel-zero/framework": "^10.2",
         "league/csv": "^9.0",
@@ -17,9 +18,7 @@
     },
     "autoload": {
         "psr-4": {
-            "App\\": "app/",
-            "Database\\Factories\\": "database/factories/",
-            "Database\\Seeders\\": "database/seeders/"
+            "App\\": "app/"
         }
     },
     "autoload-dev": {