Set outputLength correctly on open ended range requests to encryptedB…

…lobStore

Open ended ranged requests to encrypted files resulted in incorrect Content-Length headers in the response because of a bug in the Decryption class.  In EncryptedBlobStore the length is set to -1 by default. On open-ended ranged GET requests this value is passed to the Decryption constructor, which in turn only sets outputLength if an offset is given without a length, but -1 is used to represent no length given. After this change the outputLength is set correctly in this constructor.  Fixes #698.

src/main/java/org/gaul/s3proxy/crypto/Decryption.java

@@ -136,8 +136,8 @@ public Decryption(SecretKeySpec key, BlobStore blobStore,
         // calculate the offset
         calculateOffset(offset);
 
-        // if there is a offset and a length set the output length
-        if (offset > 0 && length == 0) {
+        // if there is a offset and no length set the output length
+        if (offset > 0 && length <= 0) {
             outputLength = unencryptedSize - offset;
         }
     }

src/test/java/org/gaul/s3proxy/EncryptedBlobStoreLiveTest.java

@@ -159,11 +159,29 @@ public void testPartialContent() throws InterruptedException, IOException {
         options.range(0, 19);
         object = this.getApi().getObject(containerName, blobName, options);
 
-        InputStreamReader r =
-            new InputStreamReader(object.getPayload().openStream());
+        InputStreamReader r = new InputStreamReader(
+                object.getPayload().openStream());
         BufferedReader reader = new BufferedReader(r);
-        String partialContent = reader.lines().collect(Collectors.joining());
-        assertThat(partialContent).isEqualTo(content.substring(0, 20));
+        String partialContent = reader.lines()
+                .collect(Collectors.joining());
+
+        assertThat(partialContent).isEqualTo(
+                content.substring(0, 20));
+        assertThat((long) partialContent.length()).isEqualTo(
+                object.getMetadata().getContentMetadata().getContentLength());
+
+        // open ended range request
+        options = new GetOptions();
+        options.startAt(10);
+        object = this.getApi().getObject(containerName, blobName, options);
+
+        r = new InputStreamReader(object.getPayload().openStream());
+        reader = new BufferedReader(r);
+        partialContent = reader.lines().collect(Collectors.joining());
+
+        assertThat(partialContent).isEqualTo(content.substring(10));
+        assertThat((long) partialContent.length()).isEqualTo(
+                object.getMetadata().getContentMetadata().getContentLength());
     }
 
     @Test