Reject unadvertised encodings

net/url_request/url_request_http_job.cc

Index: net/url_request/url_request_http_job.cc
diff --git a/net/url_request/url_request_http_job.cc b/net/url_request/url_request_http_job.cc
index b3053b24325a37a5a659adab66e0f56c65c0cc92..4db9ec146350df6f80b69e37a176eeb03afc6523 100644
--- a/net/url_request/url_request_http_job.cc
+++ b/net/url_request/url_request_http_job.cc
@@ -76,12 +76,6 @@ static const char kAvailDictionaryHeader[] = "Avail-Dictionary";
 
 namespace {
 
-const char kDeflate[] = "deflate";
-const char kGZip[] = "gzip";
-const char kSdch[] = "sdch";
-const char kXGZip[] = "x-gzip";
-const char kBrotli[] = "br";
-
 // True if the request method is "safe" (per section 4.2.1 of RFC 7231).
 bool IsMethodSafe(const std::string& method) {
   return method == "GET" || method == "HEAD" || method == "OPTIONS" ||
@@ -1064,22 +1058,31 @@ std::unique_ptr<SourceStream> URLRequestHttpJob::SetUpSourceStream() {
   std::vector<SourceStream::SourceType> types;
   size_t iter = 0;
   while (headers->EnumerateHeader(&iter, "Content-Encoding", &type)) {
-    if (base::LowerCaseEqualsASCII(type, kBrotli)) {
-      types.push_back(SourceStream::TYPE_BROTLI);
-    } else if (base::LowerCaseEqualsASCII(type, kDeflate)) {
-      types.push_back(SourceStream::TYPE_DEFLATE);
-    } else if (base::LowerCaseEqualsASCII(type, kGZip) ||
-               base::LowerCaseEqualsASCII(type, kXGZip)) {
-      types.push_back(SourceStream::TYPE_GZIP);
-    } else if (base::LowerCaseEqualsASCII(type, kSdch)) {
+    SourceStream::SourceType source_type =
+        FilterSourceStream::ParseEncodingType(type);
+    if (source_type == SourceStream::TYPE_SDCH &&
+        !request()->context()->sdch_manager()) {
       // If SDCH support is not configured, pass through raw response.
-      if (!request()->context()->sdch_manager())
-        return upstream;
-      types.push_back(SourceStream::TYPE_SDCH);
-    } else {
-      // Unknown encoding type. Pass through raw response body.
       return upstream;
     }
+    switch (source_type) {
+      case SourceStream::TYPE_BROTLI:
+      case SourceStream::TYPE_DEFLATE:
+      case SourceStream::TYPE_GZIP:
+      case SourceStream::TYPE_SDCH:
+        types.push_back(source_type);
+        break;
+      case SourceStream::TYPE_NONE:
+        // Identity encoding type. Pass through raw response body.
+        return upstream;
+      default:
+        // Unknown encoding type. Pass through raw response body.
+        // Despite of reporting to UMA, request will not be canceled; though
+        // it is expected that user will see malformed / garbage response.
+        FilterSourceStream::ReportContentDecodingFailed(
+            FilterSourceStream::TYPE_UNKNOWN);
+        return upstream;
+    }
   }
 
   // Sdch specific hacks:
@@ -1119,6 +1122,8 @@ std::unique_ptr<SourceStream> URLRequestHttpJob::SetUpSourceStream() {
         break;
       case SourceStream::TYPE_NONE:
       case SourceStream::TYPE_INVALID:
+      case SourceStream::TYPE_REJECTED:
+      case SourceStream::TYPE_UNKNOWN:
       case SourceStream::TYPE_MAX:
         NOTREACHED();
         return nullptr;