bugfix: dot segment handling (aws#2835)

Author: stobrien89

.changes/nextrelease/s3-dot-segment.json

@@ -0,0 +1,7 @@
+[
+  {
+    "type": "bugfix",
+    "category": "s3",
+    "description": "Disables transformation of request URI paths with dot segments"
+  }
+]

src/Api/Serializer/RestSerializer.php

@@ -242,14 +242,21 @@ function (array $matches) use ($varDefinitions) {
                 $path = rtrim($path, '/');
             }
             $relative = $path . $relative;
+
+            if (strpos($relative, '../') !== false) {
+                if ($relative[0] !== '/') {
+                    $relative = '/' . $relative;
+                }
+                return new Uri($this->endpoint . $relative);
+            }
         }
         // If endpoint has path, remove leading '/' to preserve URI resolution.
         if ($path && $relative[0] === '/') {
             $relative = substr($relative, 1);
         }
 
-        //Append path to endpoint when leading '//...' present
-        // as uri cannot be properly resolved
+        //Append path to endpoint when leading '//...'
+        // present as uri cannot be properly resolved
         if ($this->api->isModifiedModel()
             && strpos($relative, '//') === 0
         ) {

tests/S3/S3ClientTest.php

@@ -2321,4 +2321,57 @@ public function testDoesNotComputeMD5($options, $operation)
         );
         $s3->execute($command);
     }
+
+    /**
+     * @dataProvider dotSegmentProvider
+     */
+    public function testHandlesDotSegmentsInKey($key, $expectedUri)
+    {
+        $s3 = $this->getTestClient('s3');
+        $this->addMockResults($s3, [[]]);
+        $command = $s3->getCommand('getObject', ['Bucket' => 'foo', 'Key' => $key]);
+        $command->getHandlerList()->appendSign(
+            Middleware::tap(function ($cmd, $req) use ($expectedUri) {
+                $this->assertSame($expectedUri, (string) $req->getUri());
+            })
+        );
+        $s3->execute($command);
+    }
+
+    public function dotSegmentProvider()
+    {
+        return [
+            ['../foo' , 'https://foo.s3.amazonaws.com/../foo'],
+            ['bar/../../foo', 'https://foo.s3.amazonaws.com/bar/../../foo'],
+            ['/../foo', 'https://foo.s3.amazonaws.com//../foo'],
+            ['foo/bar/../baz', 'https://foo.s3.amazonaws.com/foo/bar/../baz']
+        ];
+    }
+
+    /**
+     * @dataProvider dotSegmentPathStyleProvider
+     */
+    public function testHandlesDotSegmentsInKeyWithPathStyle($key, $expectedUri)
+    {
+        $s3 = $this->getTestClient('s3', ['use_path_style_endpoint' => true]);
+        $this->addMockResults($s3, [[]]);
+        $command = $s3->getCommand('getObject', ['Bucket' => 'foo', 'Key' => $key]);
+        $command->getHandlerList()->appendSign(
+            Middleware::tap(function ($cmd, $req) use ($expectedUri) {
+                $this->assertSame($expectedUri, (string) $req->getUri());
+            })
+        );
+        $s3->execute($command);
+    }
+
+    public function dotSegmentPathStyleProvider()
+    {
+        return [
+            ['../foo' , 'https://s3.amazonaws.com/foo/foo/../foo'],
+            ['bar/../../foo', 'https://s3.amazonaws.com/foo/foo/bar/../../foo'],
+            ['/../foo', 'https://s3.amazonaws.com/foo/foo//../foo'],
+            ['foo/bar/../baz', 'https://s3.amazonaws.com/foo/foo/foo/bar/../baz'],
+        ];
+    }
+
 }