Add additional path traversal tests to protect against regressions. (#5133)

Author: millems

services/s3/src/test/java/software/amazon/awssdk/services/s3/PathTraversalTest.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.awssdk.services.s3;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+import software.amazon.awssdk.auth.credentials.AnonymousCredentialsProvider;
+import software.amazon.awssdk.regions.Region;
+import software.amazon.awssdk.testutils.service.http.MockHttpClient;
+import software.amazon.awssdk.testutils.service.http.MockSyncHttpClient;
+
+public class PathTraversalTest {
+    private static S3Client client;
+    private static MockSyncHttpClient httpClient;
+
+    @BeforeClass
+    public static void setup() {
+        httpClient = new MockSyncHttpClient();
+        client = S3Client.builder()
+                         .region(Region.US_WEST_2)
+                         .credentialsProvider(AnonymousCredentialsProvider.create())
+                         .httpClient(httpClient)
+                         .build();
+    }
+
+    @Test
+    public void clientPreservesLeadingDotSegmentInUriLabel() {
+        httpClient.stubNextResponse200();
+        client.getObjectAsBytes(r -> r.bucket("mybucket").key("../key.txt"));
+        assertThat(httpClient.getLastRequest().encodedPath()).isEqualTo("/../key.txt");
+    }
+
+    @Test
+    public void clientPreservesEmbeddedDotSegmentInUriLabel() {
+        httpClient.stubNextResponse200();
+        client.getObjectAsBytes(r -> r.bucket("mybucket").key("foo/../key.txt"));
+        assertThat(httpClient.getLastRequest().encodedPath()).isEqualTo("/foo/../key.txt");
+    }
+}