From 46a2a634df57067426da8ed53e815ddb60f1d67b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Mu=CC=88nch?= <dani.munch@gmail.com>
Date: Sat, 15 Oct 2016 20:16:53 +0200
Subject: [PATCH 1/2] Make auth handlers configurable.

---
 src/chttpd.erl | 35 +++++++++++++++++++++++++++++++----
 1 file changed, 31 insertions(+), 4 deletions(-)

diff --git a/src/chttpd.erl b/src/chttpd.erl
index d55aa5e..dec1547 100644
--- a/src/chttpd.erl
+++ b/src/chttpd.erl
@@ -117,6 +117,8 @@ start_link(Name, Options) ->
          end,
     ok = couch_httpd:validate_bind_address(IP),
 
+    set_auth_handlers(),
+
     Options1 = Options ++ [
         {loop, fun ?MODULE:handle_request/1},
         {name, Name},
@@ -464,12 +466,37 @@ extract_cookie(#httpd{mochi_req = MochiReq}) ->
     end.
 %%% end hack
 
-authenticate_request(Req) ->
-    AuthenticationFuns = [
-        {<<"cookie">>, fun chttpd_auth:cookie_authentication_handler/1},
-        {<<"default">>, fun chttpd_auth:default_authentication_handler/1},
+set_auth_handlers() ->
+    AuthenticationDefault =  "{chttpd_auth, cookie_authentication_handler},
+      {chttpd_auth, default_authentication_handler}",
+    AuthenticationSrcs = couch_httpd:make_fun_spec_strs(
+        config:get("chttpd", "authentication_handlers", AuthenticationDefault)),
+    AuthHandlers = lists:map(
+        fun(A) -> {auth_handler_name(A), couch_httpd:make_arity_1_fun(A)} end, AuthenticationSrcs),
+    AuthenticationFuns = AuthHandlers ++ [
         fun chttpd_auth:party_mode_handler/1 %% must be last
     ],
+    ok = application:set_env(chttpd, auth_handlers, AuthenticationFuns).
+
+% SpecStr is a string like "{my_module, my_fun}"
+% Takes the first token of the function name in front '_' as auth handler name
+% e.g. 
+% chttpd_auth:default_authentication_handler: default
+% chttpd_auth_cookie_authentication_handler: cookie
+% couch_http_auth:proxy_authentication_handler: proxy
+%
+% couch_http:auth_handler_name can't be used here, since it assumes the name 
+% of the auth handler to be the 6th token split by [\\W_]
+% - this only works for modules with exactly two underscores in their name
+% - is not very robust (a space after the ',' is assumed) 
+auth_handler_name(SpecStr) ->
+    case couch_util:parse_term(SpecStr) of
+    {ok, {_, Fun}} ->
+        hd(string:tokens(atom_to_list(Fun), "_"))
+    end.
+
+authenticate_request(Req) ->
+    {ok, AuthenticationFuns} = application:get_env(chttpd, auth_handlers),
     authenticate_request(Req, chttpd_auth_cache, AuthenticationFuns).
 
 authenticate_request(#httpd{} = Req0, AuthModule, AuthFuns) ->

From f28d30fe5014627199176b18d1ce28125dab8e25 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Mu=CC=88nch?= <dani.munch@gmail.com>
Date: Mon, 17 Oct 2016 15:26:10 +0200
Subject: [PATCH 2/2] Use pattern matching instead of case statement with
 single cause

---
 src/chttpd.erl | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/chttpd.erl b/src/chttpd.erl
index dec1547..b3e74d2 100644
--- a/src/chttpd.erl
+++ b/src/chttpd.erl
@@ -490,10 +490,8 @@ set_auth_handlers() ->
 % - this only works for modules with exactly two underscores in their name
 % - is not very robust (a space after the ',' is assumed) 
 auth_handler_name(SpecStr) ->
-    case couch_util:parse_term(SpecStr) of
-    {ok, {_, Fun}} ->
-        hd(string:tokens(atom_to_list(Fun), "_"))
-    end.
+    {ok, {_, Fun}} = couch_util:parse_term(SpecStr),
+    hd(string:tokens(atom_to_list(Fun), "_")).
 
 authenticate_request(Req) ->
     {ok, AuthenticationFuns} = application:get_env(chttpd, auth_handlers),