From: Kyle Nekritz <knekritz@fb.com>
Date: Tue, 16 Aug 2016 16:53:26 +0000 (-0700)
Subject: Fix extension length counter in client hello parsing.
X-Git-Tag: v2016.08.22.00~31
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=930cf1629bae8e6e2619d101f4a576aad2488e68;p=folly.git

Fix extension length counter in client hello parsing.

Summary: Orvid noticed this was always throwing on a properly formated client hello, since the sig algs extension length isn't subtracted from the counter. This doesn't actually affect any behavior (except possibly a slight perf hit), but is pretty clowny.

Reviewed By: anirudhvr

Differential Revision: D3722887

fbshipit-source-id: 579993caac96da24fb567ab977b09fca519750a0
---

diff --git a/folly/io/async/AsyncSSLSocket.cpp b/folly/io/async/AsyncSSLSocket.cpp
index b398e31c..721fb295 100644
--- a/folly/io/async/AsyncSSLSocket.cpp
+++ b/folly/io/async/AsyncSSLSocket.cpp
@@ -1651,6 +1651,7 @@ void AsyncSSLSocket::clientHelloParsingCallback(int written,
         extensionsLength -= 2;
         uint16_t extensionDataLength = cursor.readBE<uint16_t>();
         extensionsLength -= 2;
+        extensionsLength -= extensionDataLength;
 
         if (extensionType == ssl::TLSExtension::SIGNATURE_ALGORITHMS) {
           cursor.skip(2);
@@ -1666,7 +1667,6 @@ void AsyncSSLSocket::clientHelloParsingCallback(int written,
           }
         } else {
           cursor.skip(extensionDataLength);
-          extensionsLength -= extensionDataLength;
         }
       }
     }