Improve code readability

vulnerabilities/open_redirect/source/high.php

@@ -1,21 +1,16 @@
 <?php
 
-if (array_key_exists ("redirect", $_GET) && $_GET['redirect'] != "") {
+if (!empty($_GET['redirect'])) {
 	if (strpos($_GET['redirect'], "info.php") !== false) {
 		header ("location: " . $_GET['redirect']);
 		exit;
 	} else {
-		http_response_code (500);
-		?>
-		<p>You can only redirect to the info page.</p>
-		<?php
+		echo "You can only redirect to the info page.";
 		exit;
 	}
 }
 
 http_response_code (500);
-?>
-<p>Missing redirect target.</p>
-<?php
+echo "Missing redirect target.";
 exit;
 ?>

vulnerabilities/open_redirect/source/impossible.php

@@ -1,29 +1,23 @@
 <?php
 
-$target = "";
+$redirects = [
+    1 => "info.php?id=1",
+    2 => "info.php?id=2",
+    99 => "https://digi.ninja",
+];
 
-if (array_key_exists ("redirect", $_GET) && is_numeric($_GET['redirect'])) {
-	switch (intval ($_GET['redirect'])) {
-		case 1:
-			$target = "info.php?id=1";
-			break;
-		case 2:
-			$target = "info.php?id=2";
-			break;
-		case 99:
-			$target = "https://digi.ninja";
-			break;
-	}
-	if ($target != "") {
-		header ("location: " . $target);
-		exit;
-	} else {
-		?>
-		Unknown redirect target.
-		<?php
-		exit;
-	}
+if (!empty($_GET['redirect'])) {
+    $redirectId = $_GET['redirect'];
+    $target = $redirects[$redirectId] ?? "";
+    if ($target !== "") {
+        header("Location: " . $target);
+        exit;
+    } else {
+        echo "Unknown redirect target.";
+        exit;
+    }
 }
 
+echo "Missing redirect target.";
+exit;
 ?>
-Missing redirect target.

vulnerabilities/open_redirect/source/low.php

@@ -1,13 +1,11 @@
 <?php
 
-if (array_key_exists ("redirect", $_GET) && $_GET['redirect'] != "") {
+if (!empty($_GET['redirect'])) {
 	header ("location: " . $_GET['redirect']);
 	exit;
 }
 
 http_response_code (500);
-?>
-<p>Missing redirect target.</p>
-<?php
+echo "Missing redirect target.";
 exit;
 ?>

vulnerabilities/open_redirect/source/medium.php

@@ -1,11 +1,9 @@
 <?php
 
-if (array_key_exists ("redirect", $_GET) && $_GET['redirect'] != "") {
+if (!empty($_GET['redirect'])) {
 	if (preg_match ("/http:\/\/|https:\/\//i", $_GET['redirect'])) {
 		http_response_code (500);
-		?>
-		<p>Absolute URLs not allowed.</p>
-		<?php
+		echo "Absolute URLs not allowed.";
 		exit;
 	} else {
 		header ("location: " . $_GET['redirect']);
@@ -14,8 +12,6 @@
 }
 
 http_response_code (500);
-?>
-<p>Missing redirect target.</p>
-<?php
+echo "Missing redirect target.";
 exit;
 ?>