initial cut at OpenSSL support

The current CA model and code quality of OpenSSL have long put me off
from supporting TLS; however but efforts such as "Let's Encrypt"
and the fallout from Heartbleed give me hope for the future.

This implements, as much as possible, a "hands-off" approach to TLS
support via OpenSSL.  This implementation allows us to shift
responsibility away from us to users and upstreams (the Ruby 'openssl'
extension maintainers, software packagers, and OpenSSL project itself).

This is also perhaps the easiest way for now for us, while being most
powerful for users.  It requires users to configure their own OpenSSL
context object which we'll use as-is.

This context object is used as the :ssl_ctx parameter to the "listen"
directive in the yahns configuration file:

	require 'openssl' # we will not do this for the user, even
        ctx = OpenSSL::SSL::SSLContext.new
	# user must configure ctx here...
	listen 443, ssl_ctx: ctx

This way, in case we support GnuTLS or other TLS libraries, there'll
be less confusion as to what a user is actually using.

Note: this feature requires Ruby 2.1 and later for non-kgio
{read,write}_nonblock(.. exception: false) support.

1 files changed, 13 insertions, 4 deletions

diff --git a/lib/yahns/socket_helper.rb b/lib/yahns/socket_helper.rb
index 6e1830f..66df8b0 100644
--- a/lib/yahns/socket_helper.rb
+++ b/lib/yahns/socket_helper.rb
@@ -16,7 +16,7 @@ module Yahns::SocketHelper # :nodoc:
   end
 
   def set_server_sockopt(sock, opt)
-    opt = {backlog: 1024}.merge!(opt || {})
+    opt = {backlog: 1024}.merge!(opt)
     sock.close_on_exec = true
 
     TCPSocket === sock and sock.setsockopt(:IPPROTO_TCP, :TCP_NODELAY, 1)
@@ -97,7 +97,12 @@ module Yahns::SocketHelper # :nodoc:
 
     sock.bind(Socket.pack_sockaddr_in(port, addr))
     sock.autoclose = false
-    Yahns::TCPServer.for_fd(sock.fileno)
+
+    if ssl_ctx = opt[:ssl_ctx]
+      Yahns::OpenSSLServer.wrap(sock.fileno, ssl_ctx)
+    else
+      Yahns::TCPServer.for_fd(sock.fileno)
+    end
   end
 
   # returns rfc2732-style (e.g. "[::1]:666") addresses for IPv6
@@ -128,11 +133,15 @@ module Yahns::SocketHelper # :nodoc:
   end
 
   # casts a given Socket to be a TCPServer or UNIXServer
-  def server_cast(sock)
+  def server_cast(sock, opts)
     sock.autoclose = false
     begin
       Socket.unpack_sockaddr_in(sock.getsockname)
-      Yahns::TCPServer.for_fd(sock.fileno)
+      if ssl_ctx = opts[:ssl_ctx]
+        Yahns::OpenSSLServer.wrap(sock.fileno, ssl_ctx)
+      else
+        Yahns::TCPServer.for_fd(sock.fileno)
+      end
     rescue ArgumentError
       Yahns::UNIXServer.for_fd(sock.fileno)
     end