From: Raphaël Gertz <git@rapsys.eu>
Date: Thu, 14 Nov 2019 22:22:42 +0000 (+0100)
Subject: Change alphabet generation
X-Git-Tag: 0.1.0~4
X-Git-Url: https://git.rapsys.eu/userbundle/commitdiff_plain/9fc280d8e9c1d65b9cddda1ce1644fc03322ffb8?ds=sidebyside

Change alphabet generation
Fix a huge regression with recent php7 smart behaviour which resulter in data corruption
Various cleanup
---

diff --git a/Utils/Slugger.php b/Utils/Slugger.php
index f3d8e25..2172515 100644
--- a/Utils/Slugger.php
+++ b/Utils/Slugger.php
@@ -2,23 +2,67 @@
 
 namespace Rapsys\UserBundle\Utils;
 
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
 class Slugger {
 	//The secret parameter
 	private $secret;
 
+	//The alpha array
+	private $alpha;
+
+	//The rev array
+	private $rev;
+
+	//The alpha array key number
+	private $count;
+
 	//The offset reduced from secret
 	private $offset;
 
 	//Retrieve secret and set offset from reduction
-	public function __construct(\Symfony\Component\DependencyInjection\ContainerInterface $container) {
+	public function __construct(ContainerInterface $container) {
 		//Set secret
-		$this->secret = $container->getParameter('secret');
+		$this->secret = $container->getParameter('kernel.secret');
+
+		//Pseudo-random alphabet
+		//XXX: use array flip and keys to workaround php "smart" that cast range('0', '9') as int instead of string
+		//XXX: The key count mismatch, count(alpha)>count(rev), resulted in a data corruption due to duplicate numeric values
+		//TODO: set this as a parameter generated once in a command ?
+		$this->alpha = array_keys(array_flip(array_merge(
+			range('^', '[', -1),
+			range('V', 'Z'),
+			range('9', '7', -1),
+			range('L', 'O'),
+			range('f', 'a', -1),
+			range('_', '`'),
+			range('3', '0', -1),
+			range('E', 'H'),
+			range('v', 'r', -1),
+			range('+', '/'),
+			range('K', 'I', -1),
+			range('g', 'j'),
+			range('=', ':', -1),
+			range('>', '@'),
+			range('m', 'k', -1),
+			range('4', '6'),
+			range('*', '%', -1),
+			range('n', 'q'),
+			range('U', 'P', -1),
+			range(' ', '$'),
+			range('D', 'A', -1),
+			range('w', 'z'),
+			range('~', '!', -1)
+		)));
 
 		//Init rev array
-		$rev = array_flip(array_merge(range('0', '9'), range('a', 'z'), range('A', 'Z'), range('!', '~')));
+		$this->count = count($rev = $this->rev = array_flip($this->alpha));
+
+		//Init split
+		$split = str_split($this->secret);
 
 		//Set offset
-		$this->offset = array_reduce(str_split($this->secret), function ($res, $a) use ($rev) { return $res += $rev[$a]; }, count($this->secret)) % count($rev);
+		$this->offset = array_reduce($split, function ($res, $a) use ($rev) { return $res += $rev[$a]; }, count($split)) % $this->count;
 	}
 
 	//Short the string
@@ -26,24 +70,16 @@ class Slugger {
 		//Return string
 		$ret = '';
 
-		//Alphabet
-		$alpha = array_merge(range('0', '9'), range('a', 'z'), range('A', 'Z'), range('!', '~'));
-
-		//Reverse alphabet
-		$rev = array_flip($alpha);
-
-		//Number characters
-		$count = count($alpha);
-
 		//Iterate on each character
-		foreach(str_split($string) as $c) {
-			if (isset($rev[$c]) && isset($alpha[($rev[$c]+$this->offset)%$count])) {
-				$ret .= $alpha[($rev[$c]+$this->offset)%$count];
+		foreach(str_split($string) as $k => $c) {
+			if (isset($this->rev[$c]) && isset($this->alpha[($this->rev[$c]+$this->offset)%$this->count])) {
+				//XXX: Remap char to an other one
+				$ret .= chr(($this->rev[$c] - $this->offset + $this->count) % $this->count);
 			}
 		}
 
 		//Send result
-		return str_replace(array('+','/'), array('-','_'), base64_encode($ret));
+		return str_replace(['+','/'], ['-','_'], base64_encode($ret));
 	}
 
 	//Unshort the string
@@ -51,20 +87,10 @@ class Slugger {
 		//Return string
 		$ret = '';
 
-		//Alphabet
-		$alpha = array_merge(range('0', '9'), range('a', 'z'), range('A', 'Z'), range('!', '~'));
-
-		//Reverse alphabet
-		$rev = array_flip($alpha);
-
-		//Number characters
-		$count = count($alpha);
-
 		//Iterate on each character
-		foreach(str_split(base64_decode(str_replace(array('-','_'), array('+','/'), $string))) as $c) {
-			if (isset($rev[$c]) && isset($alpha[($rev[$c]-$this->offset+$count)%$count])) {
-				$ret .= $alpha[($rev[$c]-$this->offset+$count)%$count];
-			}
+		foreach(str_split(base64_decode(str_replace(['-','_'], ['+','/'], $string))) as $c) {
+			//XXX: Reverse map char to an other one
+			$ret .= $this->alpha[(ord($c) + $this->offset) % $this->count];
 		}
 
 		//Send result
@@ -73,12 +99,11 @@ class Slugger {
 
 	//Crypt and base64uri encode string
 	public function hash($string) {
-		return str_replace(array('+','/'), array('-','_'), base64_encode(crypt($string, $this->secret)));
+		return str_replace(['+','/'], ['-','_'], base64_encode(crypt($string, $this->secret)));
 	}
 
 	//Convert string to safe slug
 	function slug($string) {
-		return preg_replace('/[\/_|+ -]+/', '-', strtolower(trim(preg_replace('/[^a-zA-Z0-9\/_|+ -]/', '', str_replace(array('\'', '"'), ' ', iconv('UTF-8', 'ASCII//TRANSLIT', $string))), '-')));
+		return preg_replace('/[\/_|+ -]+/', '-', strtolower(trim(preg_replace('/[^a-zA-Z0-9\/_|+ -]/', '', str_replace(['\'', '"'], ' ', iconv('UTF-8', 'ASCII//TRANSLIT', $string))), '-')));
 	}
-
 }