From f5c1bfc232e1ad2cdb8782a4ce111d628ac8937a Mon Sep 17 00:00:00 2001
From: Joe DeVivo <joe@devivo.com>
Date: Wed, 16 Mar 2016 10:08:23 -0700
Subject: [PATCH] Added tests for RFC-7540 Section 3.5

---
 src/http2_connection.erl      | 27 ++++++++++---
 test/http2_spec_3_5_SUITE.erl | 75 +++++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+), 5 deletions(-)
 create mode 100644 test/http2_spec_3_5_SUITE.erl

diff --git a/src/http2_connection.erl b/src/http2_connection.erl
index 873423f1..2f99b168 100644
--- a/src/http2_connection.erl
+++ b/src/http2_connection.erl
@@ -1206,8 +1206,9 @@ start_http2_server(
     }=Conn) ->
     lager:info("[server] StartHTTP2 settings: ~p",
                [Http2Settings]),
-    case sock:recv(Socket, length(?PREFACE), 5000) of
-        {ok, <<?PREFACE>>} ->
+
+    case accept_preface(Socket) of
+        ok ->
             ok = active_once(Socket),
             NewState =
                 Conn#connection{
@@ -1219,9 +1220,25 @@ start_http2_server(
              handshake,
              send_settings(Http2Settings, NewState)
             };
-        BadPreface ->
-            lager:debug("[server] Bad Preface: ~p", [BadPreface]),
-            go_away(?PROTOCOL_ERROR, Conn)
+        {error, invalid_preface} ->
+            lager:debug("[server] Invalid Preface"),
+            {next_state, closing, Conn}
+    end.
+
+%% We're going to iterate through the preface string until we're done
+%% or hit a mismatch
+accept_preface(Socket) ->
+    accept_preface(Socket, <<?PREFACE>>).
+
+accept_preface(_Socket, <<>>) ->
+    ok;
+accept_preface(Socket, <<Char:8,Rem/binary>>) ->
+    case sock:recv(Socket, 1, 5000) of
+        {ok, <<Char>>} ->
+            accept_preface(Socket, Rem);
+        _E ->
+            sock:close(Socket),
+            {error, invalid_preface}
     end.
 
 %% Incoming data is a series of frames. With a passive socket we can just:
diff --git a/test/http2_spec_3_5_SUITE.erl b/test/http2_spec_3_5_SUITE.erl
new file mode 100644
index 00000000..ad88757e
--- /dev/null
+++ b/test/http2_spec_3_5_SUITE.erl
@@ -0,0 +1,75 @@
+-module(http2_spec_3_5_SUITE).
+
+-include("http2.hrl").
+-include_lib("eunit/include/eunit.hrl").
+-include_lib("common_test/include/ct.hrl").
+-compile([export_all]).
+
+all() ->
+    [
+     sends_invalid_connection_preface,
+     sends_incomplete_connection_preface
+    ].
+
+init_per_suite(Config) ->
+    application:ensure_started(crypto),
+    chatterbox_test_buddy:start(Config).
+
+end_per_suite(Config) ->
+    chatterbox_test_buddy:stop(Config),
+    ok.
+
+%% Inspired by https://github.com/summerwind/h2spec/blob/master/3_5.go
+sends_invalid_connection_preface(Config) ->
+    %% Preface correct except for last character
+    send_invalid_connection_preface(<<"PRI * HTTP/2.0\r\n\r\nSM\r\n\rQ">>, Config),
+    %% Preface incorrect at first character
+    send_invalid_connection_preface(<<"QRI * HTTP/2.0\r\n\r\nSM\r\n\r\n">>, Config),
+    %% Just plain wrong
+    send_invalid_connection_preface(<<"INVALID CONNECTION PREFACE\r\n\r\n">>, Config),
+    ok.
+
+send_invalid_connection_preface(Preface, _Config) ->
+    {ok, Port} = application:get_env(chatterbox, port),
+    ClientOptions = [
+               binary,
+               {packet, raw},
+               {active, false}
+              ],
+    {ok, SSLOptions} = application:get_env(chatterbox, ssl_options),
+    Options =  ClientOptions ++ SSLOptions ++ [{client_preferred_next_protocols, {client, [<<"h2">>]}}],
+
+    {ok, Socket} = ssl:connect("localhost", Port, Options),
+
+    ssl:send(Socket, Preface),
+
+    ssl:recv(Socket, 0, 1000),
+
+    {error, closed} = ssl:send(Socket, <<"something else">>),
+    {error, closed} = ssl:connection_information(Socket),
+    ok.
+
+sends_incomplete_connection_preface(_Config) ->
+    {ok, Port} = application:get_env(chatterbox, port),
+    ClientOptions = [
+               binary,
+               {packet, raw},
+               {active, false}
+              ],
+    {ok, SSLOptions} = application:get_env(chatterbox, ssl_options),
+    Options =  ClientOptions ++ SSLOptions ++ [{client_preferred_next_protocols, {client, [<<"h2">>]}}],
+
+    {ok, Socket} = ssl:connect("localhost", Port, Options),
+
+    ssl:send(Socket, <<"PRI * HTTP/2.0">>),
+
+    ssl:recv(Socket, 0, 1000),
+
+    {ok, _ConnectionInfo} = ssl:connection_information(Socket),
+
+    %% There's a 5 second timeout before the socket will be closed
+    ssl:recv(Socket, 0, 5000),
+
+    {error, closed} = ssl:send(Socket, <<"something else">>),
+    {error, closed} = ssl:connection_information(Socket),
+    ok.