connect: handle empty lines during handshake

fix #536

src/hackney_http_connect.erl

@@ -49,19 +49,19 @@ connect(ProxyHost, ProxyPort, Opts) ->
 connect(ProxyHost, ProxyPort, Opts, Timeout)
   when is_list(ProxyHost), is_integer(ProxyPort),
        (Timeout =:= infinity orelse is_integer(Timeout)) ->
-  
+
   %% get the  host and port to connect from the options
   Host = proplists:get_value(connect_host, Opts),
   Port = proplists:get_value(connect_port, Opts),
   Transport = proplists:get_value(connect_transport, Opts),
-  
+
   %% filter connection options
   AcceptedOpts =  [linger, nodelay, send_timeout,
     send_timeout_close, raw, inet6],
   BaseOpts = [binary, {active, false}, {packet, 0}, {keepalive,  true},
     {nodelay, true}],
   ConnectOpts = hackney_util:filter_options(Opts, AcceptedOpts, BaseOpts),
-  
+
   %% connnect to the proxy, and upgrade the socket if needed.
   case gen_tcp:connect(ProxyHost, ProxyPort, ConnectOpts) of
     {ok, Socket} ->
@@ -153,7 +153,7 @@ do_handshake(Socket, Host, Port, Options) ->
   ProxyUser = proplists:get_value(connect_user, Options),
   ProxyPass = proplists:get_value(connect_pass, Options, <<>>),
   ProxyPort = proplists:get_value(connect_port, Options),
-  
+
   %% set defaults headers
   HostHdr = case ProxyPort of
               80 ->
@@ -164,7 +164,7 @@ do_handshake(Socket, Host, Port, Options) ->
   UA =  hackney_request:default_ua(),
   Headers0 = [<<"Host: ", HostHdr/binary>>,
     <<"User-Agent: ", UA/binary >>],
-  
+
   Headers = case ProxyUser of
               undefined ->
                 Headers0;
@@ -174,7 +174,7 @@ do_handshake(Socket, Host, Port, Options) ->
                 Headers0 ++ [<< "Proxy-Authorization: Basic ", Credentials/binary >>]
             end,
   Path = iolist_to_binary([Host, ":", integer_to_list(Port)]),
-  
+
   Payload = [<< "CONNECT ", Path/binary, " HTTP/1.1", "\r\n" >>,
     hackney_bstr:join(lists:reverse(Headers), <<"\r\n">>),
     <<"\r\n\r\n">>],
@@ -186,13 +186,35 @@ do_handshake(Socket, Host, Port, Options) ->
   end.
 
 check_response(Socket) ->
+  check_response(<<>>, Socket, 10).
+
+check_response(_Buffer, _Socket, 0) ->
+  {error, bad_request};
+
+check_response(Buffer, Socket, N) ->
   case gen_tcp:recv(Socket, 0, ?TIMEOUT) of
     {ok, Data} ->
-      check_status(Data);
+      NBuffer = << Data/binary, Buffer/binary >>,
+      parse_first_line(Buffer, Socket, N);
     Error ->
       Error
   end.
 
+parse_first_line(Buffer, Socket, 0) ->
+   {error, line_too_long};
+parse_first_line(Buffer, Socket, N) ->
+  case match_eol(Buffer, 0) of
+    nomatch when byte_size(Buffer) > 4096 ->
+      {error, line_too_long};
+    nomatch ->
+      check_response(Buffer, Socket, N);
+    1 ->
+      << _:16, Rest/binary >> = Buffer,
+      parse_first_line(Rest, Socket, N - 1);
+    _ ->
+      check_status(Buffer)
+  end.
+
 check_status(<< "HTTP/1.1 200", _/bits >>) ->
   ok;
 check_status(<< "HTTP/1.1 201", _/bits >>) ->
@@ -204,3 +226,10 @@ check_status(<< "HTTP/1.0 201", _/bits >>) ->
 check_status(Else) ->
   error_logger:error_msg("proxy error: ~w~n", [Else]),
   {error, proxy_error}.
+
+match_eol(<< $\n, _/bits >>, N) ->
+  N;
+match_eol(<< _, Rest/bits >>, N) ->
+  match_eol(Rest, N + 1);
+match_eol(_, _) ->
+  nomatch.