Safely get stream contents (#515)

guzzle · Jun 8, 2022 · 3d12ad5 · 3d12ad5
1 parent a07b9fd
commit 3d12ad5
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Showing 6 changed files with 114 additions and 7 deletions.
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
@@ -305,6 +305,11 @@ parameters:
 			count: 1
 			path: src/UriResolver.php
 
+		-
+			message: "#^Method GuzzleHttp\\\\Psr7\\\\Utils\\:\\:tryStreamGetContents\\(\\) should return string but returns string\\|false\\.$#"
+			count: 1
+			path: src/Utils.php
+
 		-
 			message: "#^Offset 'uri' on array\\{timed_out\\: bool, blocked\\: bool, eof\\: bool, unread_bytes\\: int, stream_type\\: string, wrapper_type\\: string, wrapper_data\\: mixed, mode\\: string, \\.\\.\\.\\} on left side of \\?\\? always exists and is not nullable\\.$#"
 			count: 1
@@ -325,6 +330,11 @@ parameters:
 			count: 1
 			path: src/Utils.php
 
+		-
+			message: "#^Variable \\$contents might not be defined\\.$#"
+			count: 1
+			path: src/Utils.php
+
 		-
 			message: "#^Variable \\$handle might not be defined\\.$#"
 			count: 1

diff --git a/psalm-baseline.xml b/psalm-baseline.xml
@@ -124,10 +124,15 @@
     </TypeDoesNotContainType>
   </file>
   <file src="src/Utils.php">
-    <MissingDocblockType occurrences="1">
+    <FalsableReturnStatement occurrences="1">
+      <code>$contents</code>
+    </FalsableReturnStatement>
+    <MissingDocblockType occurrences="2">
+      <code>throw $ex;</code>
       <code>throw $ex;</code>
     </MissingDocblockType>
-    <PossiblyUndefinedVariable occurrences="1">
+    <PossiblyUndefinedVariable occurrences="2">
+      <code>$contents</code>
       <code>$handle</code>
     </PossiblyUndefinedVariable>
   </file>

diff --git a/src/Stream.php b/src/Stream.php
@@ -96,13 +96,11 @@ public function getContents(): string
             throw new \RuntimeException('Stream is detached');
         }
 
-        $contents = stream_get_contents($this->stream);
-
-        if ($contents === false) {
-            throw new \RuntimeException('Unable to read stream contents');
+        if (!$this->readable) {
+            throw new \RuntimeException('Cannot read from non-readable stream');
         }
 
-        return $contents;
+        return Utils::tryStreamGetContents($this->stream);
     }
 
     public function close(): void

diff --git a/src/Utils.php b/src/Utils.php
@@ -386,6 +386,53 @@ public static function tryFopen(string $filename, string $mode)
         return $handle;
     }
 
+    /**
+     * Safely gets the contents of a given stream.
+     *
+     * When stream_get_contents fails, PHP normally raises a warning. This
+     * function adds an error handler that checks for errors and throws an
+     * exception instead.
+     *
+     * @param resource $stream
+     *
+     * @throws \RuntimeException if the stream cannot be read
+     */
+    public static function tryStreamGetContents($stream): string
+    {
+        $ex = null;
+        set_error_handler(static function (int $errno, string $errstr) use (&$ex): bool {
+            $ex = new \RuntimeException(sprintf(
+                'Unable to read stream contents: %s',
+                $errstr
+            ));
+
+            return true;
+        });
+
+        try {
+            /** @var string|false $contents */
+            $contents = stream_get_contents($stream);
+
+            if ($contents === false) {
+                $ex = new \RuntimeException('Unable to read stream contents');
+            }
+        } catch (\Throwable $e) {
+            $ex = new \RuntimeException(sprintf(
+                'Unable to read stream contents: %s',
+                $e->getMessage()
+            ), 0, $e);
+        }
+
+        restore_error_handler();
+
+        if ($ex) {
+            /** @var $ex \RuntimeException */
+            throw $ex;
+        }
+
+        return $contents;
+    }
+
     /**
      * Returns a UriInterface for the given value.
      *

diff --git a/tests/StreamTest.php b/tests/StreamTest.php
@@ -417,6 +417,24 @@ public function testReadOnlyStreamIsNotWritable(): void
 
         $stream->close();
     }
+
+    public function testCannotReadUnreadableStream(): void
+    {
+        $r = fopen(tempnam(sys_get_temp_dir(), 'guzzle-psr7-'), 'w');
+        $stream = new Stream($r);
+
+        $stream->write("Hello world!!");
+
+        $stream->seek(0);
+
+        $this->expectException(\RuntimeException::class);
+
+        try {
+            $stream->getContents();
+        } finally {
+            $stream->close();
+        }
+    }
 }
 
 namespace GuzzleHttp\Psr7;

diff --git a/tests/UtilsTest.php b/tests/UtilsTest.php
@@ -200,6 +200,35 @@ public function testThrowsExceptionNotValueError(): void
         Psr7\Utils::tryFopen('', 'r');
     }
 
+    /**
+     * @requires PHP 7.4
+     */
+    public function testGetsContentsThrowExceptionWhenNotReadable(): void
+    {
+        $r = fopen(tempnam(sys_get_temp_dir(), 'guzzle-psr7-'), 'w');
+        fwrite($r, 'hello world!');
+
+        $this->expectException(\RuntimeException::class);
+        $this->expectExceptionMessage('Unable to read stream contents');
+
+        try {
+            Psr7\Utils::tryStreamGetContents($r);
+        } finally {
+            fclose($r);
+        }
+    }
+
+    public function testGetsContentsThrowExceptionWhenCLosed(): void
+    {
+        $r = fopen(tempnam(sys_get_temp_dir(), 'guzzle-psr7-'), 'r+');
+        fclose($r);
+
+        $this->expectException(\RuntimeException::class);
+        $this->expectExceptionMessage('Unable to read stream contents');
+
+        Psr7\Utils::tryStreamGetContents($r);
+    }
+
     public function testCreatesUriForValue(): void
     {
         self::assertInstanceOf('GuzzleHttp\Psr7\Uri', Psr7\Utils::uriFor('/foo'));