From 9c867e88779f8976631882680db9abd865d04b75 Mon Sep 17 00:00:00 2001
From: ILYA Khlopotov <iilyak@ca.ibm.com>
Date: Mon, 16 Feb 2015 12:05:57 -0800
Subject: [PATCH] Introduce an `allowed_owner` hook

COUCHDB-2585
---
 src/global_changes_httpd.erl        |  13 ++-
 test/global_changes_hooks_tests.erl | 142 ++++++++++++++++++++++++++++
 2 files changed, 153 insertions(+), 2 deletions(-)
 create mode 100644 test/global_changes_hooks_tests.erl

diff --git a/src/global_changes_httpd.erl b/src/global_changes_httpd.erl
index af25b7c..be6cfdc 100644
--- a/src/global_changes_httpd.erl
+++ b/src/global_changes_httpd.erl
@@ -41,9 +41,9 @@ handle_global_changes_req(#httpd{method='GET'}=Req) ->
     Limit = couch_util:get_value(limit, Options),
     %Options1 = lists:keydelete(limit, 1, Options),
     Options1 = Options,
-    chttpd:verify_is_server_admin(Req),
+    Owner = allowed_owner(Req),
     Acc = #acc{
-        username=admin,
+        username=Owner,
         feed=Feed,
         resp=Req,
         heartbeat_interval=Heartbeat,
@@ -248,3 +248,12 @@ to_non_neg_int(Value) ->
     catch error:badarg ->
         throw({bad_request, invalid_integer})
     end.
+
+allowed_owner(Req) ->
+    case application:get_env(global_changes, allowed_owner) of
+    undefined ->
+        chttpd:verify_is_server_admin(Req),
+        admin;
+    {ok, {M, F, A}} ->
+        M:F(Req, A)
+    end.
diff --git a/test/global_changes_hooks_tests.erl b/test/global_changes_hooks_tests.erl
new file mode 100644
index 0000000..3b6ccbc
--- /dev/null
+++ b/test/global_changes_hooks_tests.erl
@@ -0,0 +1,142 @@
+-module(global_changes_hooks_tests).
+
+-include_lib("couch/include/couch_eunit.hrl").
+-include_lib("couch/include/couch_db.hrl").
+
+-export([allowed_owner/2]).
+
+start() ->
+    Ctx = test_util:start_couch([chttpd]),
+    DbName = ?tempdb(),
+    ok = fabric:create_db(DbName, [?ADMIN_CTX]),
+    application:set_env(global_changes, dbname, DbName),
+    {Ctx, DbName}.
+
+stop({Ctx, DbName}) ->
+    ok = fabric:delete_db(DbName, [?ADMIN_CTX]),
+    test_util:stop_couch(Ctx),
+    ok.
+
+setup(default) ->
+    add_admin("admin", <<"pass">>),
+    config:delete("couch_httpd_auth", "authentication_redirect", false),
+    config:set("couch_httpd_auth", "require_valid_user", "false", false),
+    get_host();
+setup(A) ->
+    Host = setup(default),
+    ok = application:set_env(global_changes, allowed_owner,
+        {?MODULE, allowed_owner, A}),
+    Host.
+
+teardown(_) ->
+    delete_admin("admin"),
+    application:unset_env(global_changes, allowed_owner),
+    ok.
+
+allowed_owner(Req, "throw") ->
+    throw({unauthorized, <<"Exception thrown.">>});
+allowed_owner(Req, "pass") ->
+    "super".
+
+allowed_owner_hook_test_() ->
+    {
+        "Check allowed_owner hook",
+        {
+            setup,
+            fun start/0, fun stop/1,
+            [
+                disabled_allowed_owner_integration_point(),
+                enabled_allowed_owner_integration_point()
+            ]
+        }
+    }.
+
+disabled_allowed_owner_integration_point() ->
+    {
+        "disabled allowed_owner integration point",
+        {
+            foreach,
+            fun() -> setup(default) end, fun teardown/1,
+            [
+                fun should_not_fail_for_admin/1,
+                fun should_fail_for_non_admin/1
+             ]
+        }
+    }.
+
+enabled_allowed_owner_integration_point() ->
+    {
+        "enabled allowed_owner integration point",
+        [
+            {
+                foreach,
+                fun() -> setup("throw") end, fun teardown/1,
+                [fun should_throw/1]
+            },
+            {
+                foreach,
+                fun() -> setup("pass") end, fun teardown/1,
+                [fun should_pass/1]
+            }
+        ]
+    }.
+
+should_not_fail_for_admin(Host) ->
+    ?_test(begin
+        Headers = [{basic_auth, {"admin", "pass"}}],
+        {Status, [Error, Reason]} =
+            request(Host, Headers, [<<"error">>, <<"reason">>]),
+        ?assertEqual(200, Status),
+        ?assertEqual(undefined, Error),
+        ?assertEqual(undefined, Reason)
+    end).
+
+should_fail_for_non_admin(Host) ->
+    ?_test(begin
+        Headers = [],
+        {Status, [Error, Reason]} =
+            request(Host, Headers, [<<"error">>, <<"reason">>]),
+        ?assertEqual(401, Status),
+        ?assertEqual(<<"unauthorized">>, Error),
+        ?assertEqual(<<"You are not a server admin.">>, Reason)
+    end).
+
+should_pass(Host) ->
+    ?_test(begin
+        Headers = [{basic_auth, {"admin", "pass"}}],
+        {Status, [Error, Reason]} =
+            request(Host, Headers, [<<"error">>, <<"reason">>]),
+        ?assertEqual(200, Status),
+        ?assertEqual(undefined, Error),
+        ?assertEqual(undefined, Reason)
+    end).
+
+should_throw(Host) ->
+    ?_test(begin
+        Headers = [{basic_auth, {"admin", "pass"}}],
+        {Status, [Error, Reason]} =
+            request(Host, Headers, [<<"error">>, <<"reason">>]),
+        ?assertEqual(401, Status),
+        ?assertEqual(<<"unauthorized">>, Error),
+        ?assertEqual(<<"Exception thrown.">>, Reason)
+    end).
+
+request(Host, Headers, ToDecode) ->
+    Url = Host ++ "/_db_updates",
+    {ok, Status, _Headers, BinBody} = test_request:get(Url, Headers),
+    {Body} = jiffy:decode(BinBody),
+    Values = [couch_util:get_value(Key, Body) || Key <- ToDecode],
+    {Status, Values}.
+
+add_admin(User, Pass) ->
+    Hashed = couch_passwords:hash_admin_password(Pass),
+    config:set("admins", User, ?b2l(Hashed), false).
+
+delete_admin(User) ->
+    config:delete("admins", User, false).
+
+get_host() ->
+    Addr = config:get("httpd", "bind_address", "127.0.0.1"),
+    Port = config:get("chttpd", "port", "5984"),
+    Host = "http://" ++ Addr ++ ":" ++ Port,
+    Host.