Disregard possible port in the Host HTTP header

Motivation: to make it easy to switch Sproxy's primary port.
This could be useful when running private (behind Sproxy) and public
(e. g. nginx) HTTPS services on the same server.  In such a setup
one can use port 443 for public services and alt. HTTPS port 8443
for Sproxy.

Before this change, Sproxy took possible port number into account
when looking for backend and privileges. Now it ignores port and
considers domain name only.

This also gets Sproxy in line with browsers and SSL certificates:
certificates do not include port numbers, browsers ignore ports
when sending cookies.

sproxy.example.yml

@@ -147,11 +147,10 @@ ssl_key: /path/key.pem
 # Unix sockets should be secured with proper unix file permissions.
 #
 # Backend attributes:
-#   name      - the host name as in the Host HTTP header.
+#   name      - the domain name as in the Host HTTP header (without optional colon and port).
 #               May include wildcards * and ?. The first matching
 #               backend will be used. Examples: "*.example.com", "wiki.corp.com".
-#               Optional. Default is "*". Note, that the name must include
-#               port number if non-standard.
+#               Optional. Default is "*".
 #   address   - backend IP address. Optional. Default is 127.0.0.1.
 #   port      - backend TCP port. Required unless unix socket is defined.
 #   socket    - unix socket. Highly recommended for security reasons.

src/Sproxy/Application.hs

@@ -55,25 +55,24 @@ import qualified Sproxy.Logging as Log
 
 redirect :: Word16 -> W.Application
 redirect p req resp =
-  case W.requestHeaderHost req of
+  case requestDomain req of
     Nothing -> badRequest "missing host" req resp
-    Just host -> do
+    Just domain -> do
       Log.info $ "redirecting to " ++ show location ++ ": " ++ showReq req
       resp $ W.responseBuilder status [(hLocation, location)] mempty
       where
         status = if W.requestMethod req == methodGet then movedPermanently301 else temporaryRedirect307
-        (domain, _) = BS.break (== _colon) host
         newhost = if p == 443 then domain else domain <> ":" <> pack (show p)
         location = "https://" <> newhost <> W.rawPathInfo req <> W.rawQueryString req
 
 
 sproxy :: ByteString -> Database -> HashMap Text OAuth2Client -> [(Pattern, BackendConf, BE.Manager)] -> W.Application
 sproxy key db oa2 backends = logException $ \req resp -> do
   Log.debug $ "sproxy <<< " ++ showReq req
-  case W.requestHeaderHost req of
+  case requestDomain req of
     Nothing -> badRequest "missing host" req resp
-    Just host ->
-      case find (\(p, _, _) -> match p (unpack host)) backends of
+    Just domain ->
+      case find (\(p, _, _) -> match p (unpack domain)) backends of
         Nothing -> notFound "backend" req resp
         Just (_, be, mgr) -> do
           let cookieName = pack $ beCookieName be
@@ -145,8 +144,7 @@ extractCookie key now name req = do
 authenticate :: ByteString -> BackendConf -> AuthUser -> ByteString -> W.Application
 authenticate key be user path req resp = do
   now <- epochTime
-  let host = fromJust $ W.requestHeaderHost req
-      domain = pack <$> beCookieDomain be
+  let domain = pack <$> beCookieDomain be
       expiry = now + CTime (beCookieMaxAge be)
       authCookie = AuthCookie { acUser = user, acExpiry = expiry }
       cookie = WC.def {
@@ -160,7 +158,7 @@ authenticate key be user path req resp = do
       , WC.setCookieExpires = Just . posixSecondsToUTCTime . realToFrac $ expiry
       }
   resp $ W.responseLBS seeOther303 [
-           (hLocation, "https://" <> host <> path)
+           (hLocation, "https://" <> fromJust (W.requestHeaderHost req) <> path)
          , ("Set-Cookie", toByteString $ WC.renderSetCookie cookie)
          ] ""
 
@@ -169,7 +167,7 @@ authorize :: Database -> (AuthCookie, Cookies) -> W.Request -> IO (Maybe W.Reque
 authorize db (authCookie, otherCookies) req = do
   let
     user       = acUser authCookie
-    domain     = decodeUtf8 . fromJust $ W.requestHeaderHost req
+    domain     = decodeUtf8 . fromJust $ requestDomain req
     email      = getEmail user
     emailUtf8  = getEmailUtf8 user
     familyUtf8 = getFamilyNameUtf8 user
@@ -388,6 +386,12 @@ redirectURL req provider =
              <> "/.sproxy/oauth2/" <> encodeUtf8 provider
 
 
+requestDomain :: W.Request -> Maybe ByteString
+requestDomain req = do
+  h <- W.requestHeaderHost req
+  return . fst . BS.break (== _colon) $ h
+
+
 -- XXX: make sure not to reveal the cookie, which can be valid (!)
 showReq :: W.Request -> String
 showReq req =