Merge pull request #87 from browserup/brotli-support

Bring in brotli support from PR on BrowserMob

Author: ericbeland

browserup-proxy-core/build.gradle

@@ -72,6 +72,7 @@ dependencies {
     implementation 'io.netty:netty-all:4.1.36.Final'
     implementation 'org.bouncycastle:bcpkix-jdk15on:1.61'
     implementation 'org.bouncycastle:bcprov-jdk15on:1.61'
+    implementation 'org.brotli:dec:0.1.2'
     implementation 'org.javassist:javassist:3.25.0-GA'
     implementation 'org.seleniumhq.selenium:selenium-api:3.141.59'
     implementation 'org.slf4j:jcl-over-slf4j:1.7.26'

browserup-proxy-core/src/main/java/com/browserup/bup/filters/ServerResponseCaptureFilter.java

@@ -29,6 +29,7 @@
  */
 public class ServerResponseCaptureFilter extends HttpFiltersAdapter {
     private static final Logger log = LoggerFactory.getLogger(ServerResponseCaptureFilter.class);
+    private static final String BROTLI_COMPRESSION = "br";
 
     /**
      * Populated by serverToProxyResponse() when processing the HttpResponse object
@@ -132,7 +133,14 @@ protected void captureFullResponseContents() {
     protected void decompressContents() {
         if (contentEncoding.equals(HttpHeaders.Values.GZIP)) {
             try {
-                fullResponseContents = BrowserUpHttpUtil.decompressContents(getRawResponseContents());
+                fullResponseContents = BrowserUpHttpUtil.decompressGZIPContents(getRawResponseContents());
+                decompressionSuccessful = true;
+            } catch (RuntimeException e) {
+                log.warn("Failed to decompress response with encoding type " + contentEncoding + " when decoding request from " + originalRequest.getUri(), e);
+            }
+        } else if (contentEncoding.equals(BROTLI_COMPRESSION)) {
+            try {
+                fullResponseContents = BrowserUpHttpUtil.decompressBrotliContents(getRawResponseContents());
                 decompressionSuccessful = true;
             } catch (RuntimeException e) {
                 log.warn("Failed to decompress response with encoding type " + contentEncoding + " when decoding request from " + originalRequest.getUri(), e);

browserup-proxy-core/src/main/java/com/browserup/bup/util/BrowserUpHttpUtil.java

@@ -7,6 +7,7 @@
 import com.google.common.io.BaseEncoding;
 import com.google.common.net.HostAndPort;
 import com.google.common.net.MediaType;
+import org.brotli.dec.BrotliInputStream;
 import io.netty.buffer.ByteBuf;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.HttpRequest;
@@ -16,6 +17,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.InputStream;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -79,11 +81,11 @@ public static long getHeaderSize(HttpHeaders headers) {
     /**
      * Decompresses the gzipped byte stream.
      *
-     * @param fullMessage gzipped byte stream to decomress
+     * @param fullMessage gzipped byte stream to decompress
      * @return decompressed bytes
      * @throws DecompressionException thrown if the fullMessage cannot be read or decompressed for any reason
      */
-    public static byte[] decompressContents(byte[] fullMessage) throws DecompressionException {
+    public static byte[] decompressGZIPContents(byte[] fullMessage) throws DecompressionException {
         InflaterInputStream gzipReader = null;
         ByteArrayOutputStream uncompressed;
         try {
@@ -113,6 +115,42 @@ public static byte[] decompressContents(byte[] fullMessage) throws Decompression
     }
 
     /**
+     * Decompresses the brotli byte stream
+     *
+     * @param fullMessage brotli byte stream to decompress
+     * @return decompressed bytes
+     * @throws DecompressionException thrown if the fullMessage cannot be read or decompressed for any reason
+     */
+    public static byte[] decompressBrotliContents(byte[] fullMessage) throws DecompressionException {
+        InputStream brotliReader = null;
+        ByteArrayOutputStream uncompressed;
+        try {
+            brotliReader = new BrotliInputStream(new ByteArrayInputStream(fullMessage));
+
+            uncompressed = new ByteArrayOutputStream(fullMessage.length);
+
+            byte[] decompressBuffer = new byte[DECOMPRESS_BUFFER_SIZE];
+            int bytesRead;
+            while ((bytesRead = brotliReader.read(decompressBuffer)) > -1) {
+                uncompressed.write(decompressBuffer, 0, bytesRead);
+            }
+
+            fullMessage = uncompressed.toByteArray();
+        } catch (IOException e) {
+            throw new DecompressionException("Unable to decompress response", e);
+        } finally {
+            try {
+                if (brotliReader != null) {
+                    brotliReader.close();
+                }
+            } catch (IOException e) {
+                log.warn("Unable to close brotli stream", e);
+            }
+        }
+        return fullMessage;
+    }
+
+     /**
      * Returns true if the content type string indicates textual content. Currently these are any Content-Types that start with one of the
      * following:
      * <pre>