File size: 4,790 Bytes
27cd9bf | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 | diff --git a/src/DOMDocumentFactory.php b/src/DOMDocumentFactory.php
index 9ab2a767..14474830 100644
--- a/src/DOMDocumentFactory.php
+++ b/src/DOMDocumentFactory.php
@@ -5,15 +5,16 @@
namespace SimpleSAML\XML;
use DOMDocument;
-use RuntimeException;
use SimpleSAML\Assert\Assert;
use SimpleSAML\XML\Exception\IOException;
+use SimpleSAML\XML\Exception\RuntimeException;
use SimpleSAML\XML\Exception\UnparseableXMLException;
-use function defined;
use function file_get_contents;
+use function func_num_args;
use function libxml_clear_errors;
use function libxml_get_last_error;
+use function libxml_set_external_entity_loader;
use function libxml_use_internal_errors;
use function sprintf;
@@ -22,25 +23,41 @@
*/
final class DOMDocumentFactory
{
+ /**
+ * @var non-negative-int
+ * TODO: Add LIBXML_NO_XXE to the defaults when PHP 8.4.0 + libxml 2.13.0 become generally available
+ */
+ public const DEFAULT_OPTIONS = LIBXML_COMPACT | LIBXML_NONET | LIBXML_NSCLEAN;
+
+
/**
* @param string $xml
- * @param non-empty-string $xml
+ * @param non-negative-int $options
*
* @return \DOMDocument
*/
- public static function fromString(string $xml): DOMDocument
- {
+ public static function fromString(
+ string $xml,
+ int $options = self::DEFAULT_OPTIONS,
+ ): DOMDocument {
+ libxml_set_external_entity_loader(null);
Assert::notWhitespaceOnly($xml);
+ Assert::notRegex(
+ $xml,
+ '/<(\s*)!(\s*)DOCTYPE/',
+ 'Dangerous XML detected, DOCTYPE nodes are not allowed in the XML body',
+ RuntimeException::class,
+ );
$internalErrors = libxml_use_internal_errors(true);
libxml_clear_errors();
- $domDocument = self::create();
- $options = LIBXML_DTDLOAD | LIBXML_DTDATTR | LIBXML_NONET | LIBXML_PARSEHUGE | LIBXML_NSCLEAN;
- if (defined('LIBXML_COMPACT')) {
- $options |= LIBXML_COMPACT;
+ // If LIBXML_NO_XXE is available and option not set
+ if (func_num_args() === 1 && defined('LIBXML_NO_XXE')) {
+ $options != LIBXML_NO_XXE;
}
+ $domDocument = self::create();
$loaded = $domDocument->loadXML($xml, $options);
libxml_use_internal_errors($internalErrors);
@@ -55,11 +72,11 @@ public static function fromString(string $xml): DOMDocument
libxml_clear_errors();
foreach ($domDocument->childNodes as $child) {
- if ($child->nodeType === XML_DOCUMENT_TYPE_NODE) {
- throw new RuntimeException(
- 'Dangerous XML detected, DOCTYPE nodes are not allowed in the XML body',
- );
- }
+ Assert::false(
+ $child->nodeType === XML_DOCUMENT_TYPE_NODE,
+ 'Dangerous XML detected, DOCTYPE nodes are not allowed in the XML body',
+ RuntimeException::class,
+ );
}
return $domDocument;
@@ -68,10 +85,11 @@ public static function fromString(string $xml): DOMDocument
/**
* @param string $file
+ * @param non-negative-int $options
*
* @return \DOMDocument
*/
- public static function fromFile(string $file): DOMDocument
+ public static function fromFile(string $file, int $options = self::DEFAULT_OPTIONS): DOMDocument
{
error_clear_last();
$xml = @file_get_contents($file);
@@ -83,7 +101,7 @@ public static function fromFile(string $file): DOMDocument
}
Assert::notWhitespaceOnly($xml, sprintf('File "%s" does not have content', $file), RuntimeException::class);
- return static::fromString($xml);
+ return (func_num_args() === 1) ? static::fromString($xml) : static::fromString($xml, $options);
}
diff --git a/tests/XML/DOMDocumentFactoryTest.php b/tests/XML/DOMDocumentFactoryTest.php
index 2e01f031..79c4a6ad 100644
--- a/tests/XML/DOMDocumentFactoryTest.php
+++ b/tests/XML/DOMDocumentFactoryTest.php
@@ -84,6 +84,19 @@ public function testStringThatContainsDocTypeIsNotAccepted(): void
}
+ public function testStringThatContainsDocTypeIsNotAccepted2(): void
+ {
+ $xml = '<?xml version="1.0" encoding="ISO-8859-1"?>
+ <!DOCTYPE foo [<!ENTITY % exfiltrate SYSTEM "file://dev/random">%exfiltrate;]>
+ <foo>y</foo>';
+ $this->expectException(RuntimeException::class);
+ $this->expectExceptionMessage(
+ 'Dangerous XML detected, DOCTYPE nodes are not allowed in the XML body',
+ );
+ DOMDocumentFactory::fromString($xml);
+ }
+
+
public function testEmptyFileIsNotValid(): void
{
$file = 'resources/xml/domdocument_empty.xml';
|