Ignore Content-Length in some cases:

fix #692

The value of Content-Length is not checked for limits
when the semantics of an HTTP response indicate that
the message has no body. For example, when status is 101.

CHANGELOG.md

@@ -3,6 +3,7 @@ Version 92:
 * Fix typo in test/CMakeLists.txt
 * basic_fields::value_type is not copyable
 * Update repository links in source comments
+* Ignore Content-Length in some cases
 
 --------------------------------------------------------------------------------
 

include/boost/beast/http/impl/basic_parser.ipp

@@ -532,6 +532,11 @@ finish_header(error_code& ec, std::true_type)
     }
     else if(f_ & flagContentLength)
     {
+        if(len_ > body_limit_)
+        {
+            ec = error::body_limit;
+            return;
+        }
         if(len_ > 0)
         {
             f_ |= flagHasBody;
@@ -578,12 +583,20 @@ finish_header(error_code& ec, std::false_type)
         status_ == 204 ||        // No Content
         status_ == 304)          // Not Modified
     {
+        // VFALCO Content-Length may be present, but we
+        //        treat the message as not having a body.
+        //        https://github.com/boostorg/beast/issues/692
         state_ = state::complete;
         return;
     }
 
     if(f_ & flagContentLength)
     {
+        if(len_ > body_limit_)
+        {
+            ec = error::body_limit;
+            return;
+        }
         if(len_ > 0)
         {
             f_ |= flagHasBody;
@@ -876,12 +889,6 @@ do_field(field f,
             return;
         }
 
-        if(v > body_limit_)
-        {
-            ec = error::body_limit;
-            return;
-        }
-
         ec.assign(0, ec.category());
         len_ = v;
         f_ |= flagContentLength;

test/beast/http/basic_parser.cpp

@@ -1106,6 +1106,24 @@ public:
             });
     }
 
+    // https://github.com/boostorg/beast/issues/692
+    void
+    testIssue692()
+    {
+        error_code ec;
+        test_parser<false> p;
+        p.eager(true);
+        string_view s =
+            "HTTP/1.1 101 Switching Protocols\r\n"
+            "Content-Length: 2147483648\r\n"
+            "\r\n";
+        p.put(boost::asio::buffer(
+            s.data(), s.size()), ec);
+        if(! BEAST_EXPECTS(! ec, ec.message()))
+            return;
+        BEAST_EXPECT(p.is_done());
+    }
+
     //--------------------------------------------------------------------------
 
     void
@@ -1216,6 +1234,7 @@ public:
         testIssue430();
         testIssue452();
         testIssue496();
+        testIssue692();
         testFuzz();
         testRegression1();
     }