Add assertion to test xs:hexBinary

src/CustomAssertionTrait.php

@@ -22,6 +22,9 @@
  */
 trait CustomAssertionTrait
 {
+    /** @var string */
+    private static string $hexbin_regex = '/^([0-9a-fA-F]{2})+$/D';
+
     /** @var string */
     private static string $nmtoken_regex = '/^[\w.:-]+$/Du';
 
@@ -130,6 +133,27 @@ private static function stringPlausibleBase64(string $value, string $message = '
     }
 
 
+    /**
+     * @param string $value
+     * @param string $message
+     */
+    private static function validHexBinary(string $value, string $message = ''): void
+    {
+        $result = true;
+
+        if (filter_var($value, FILTER_VALIDATE_REGEXP, ['options' => ['regexp' => self::$hexbin_regex]]) === false) {
+            $result = false;
+        }
+
+        if ($result === false) {
+            throw new InvalidArgumentException(sprintf(
+                $message ?: '\'%s\' is not a valid hexBinary string',
+                $value,
+            ));
+        }
+    }
+
+
     /**
      * @param string $value
      * @param string $message

tests/Assert/HexBinaryTest.php

@@ -0,0 +1,51 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SimpleSAML\Test\Assert;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\TestCase;
+use SimpleSAML\Assert\Assert;
+use SimpleSAML\Assert\AssertionFailedException;
+
+/**
+ * Class \SimpleSAML\Assert\HexBinaryTest
+ *
+ * @package simplesamlphp/assert
+ */
+#[CoversClass(Assert::class)]
+final class HexBinaryTest extends TestCase
+{
+    /**
+     * @param boolean $shouldPass
+     * @param string $name
+     */
+    #[DataProvider('provideHexBinary')]
+    public function testHexBinary(bool $shouldPass, string $name): void
+    {
+        try {
+            Assert::validHexBinary($name);
+            $this->assertTrue($shouldPass);
+        } catch (AssertionFailedException $e) {
+            $this->assertFalse($shouldPass);
+        }
+    }
+
+
+    /**
+     * @return array<string, array{0: bool, 1: string}>
+     */
+    public static function provideHexBinary(): array
+    {
+        return [
+            'empty' => [false, ''],
+            'base64' => [false, 'U2ltcGxlU0FNTHBocA=='],
+            'valid' => [true, '3f3c6d78206c657673726f693d6e3122302e20226e656f636964676e223d54552d4622383e3f'],
+            'invalid' => [false, '3f3r'],
+            'bogus' => [false, '&*$(#&^@!(^%$'],
+            'length not dividable by 4' => [false, '3f3'],
+        ];
+    }
+}