From fbe8cb593f4ca40abc9bca81757b992f65ddf897 Mon Sep 17 00:00:00 2001
From: Sergey Prokhorov <seriy.pr@gmail.com>
Date: Tue, 13 Aug 2019 00:45:29 +0200
Subject: [PATCH] Allow `any` in `tls_allowed_domains`.

---
 Makefile                  |  7 ++++---
 README.md                 |  2 +-
 src/mtp_handler.erl       | 11 ++++++++---
 src/mtproto_proxy.app.src |  4 +++-
 src/mtproto_proxy_app.erl |  6 +++++-
 5 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/Makefile b/Makefile
index 9a3afe9..37f1a3d 100644
--- a/Makefile
+++ b/Makefile
@@ -13,10 +13,11 @@ all: config/prod-sys.config config/prod-vm.args
 .PHONY: test
 test:
 	$(REBAR3) xref
-	$(REBAR3) eunit
-	$(REBAR3) ct
-	$(REBAR3) proper -n 50
+	$(REBAR3) eunit -c
+	$(REBAR3) ct -c
+	$(REBAR3) proper -c -n 50
 	$(REBAR3) dialyzer
+	$(REBAR3) cover -v
 
 config/prod-sys.config: config/sys.config.example
 	[ -f $@ ] && diff $^ $@ || true
diff --git a/README.md b/README.md
index 618e392..092c576 100644
--- a/README.md
+++ b/README.md
@@ -258,7 +258,7 @@ You should disable all protocols other than `mtp_secure` by providing `allowed_p
 Another censorship circumvention technique. MTPRoto proxy protocol pretends to be
 HTTPS web traffic (technically speaking, TLSv1.3 + HTTP/2).
 It's possible to only allow connections with this protocol by changing `allowed_protocols` to
-be list with only `mtp_fake_tls`:
+be list with only `mtp_fake_tls`. You may also want to check `tls_allowed_domains` option.
 
 ```erlang
   {mtproto_proxy,
diff --git a/src/mtp_handler.erl b/src/mtp_handler.erl
index d58aeb3..5e5ce71 100644
--- a/src/mtp_handler.erl
+++ b/src/mtp_handler.erl
@@ -359,9 +359,14 @@ maybe_check_replay(Packet) ->
 check_tls_access(_Listener, _Ip, #{sni_domain := Domain}) ->
     %% TODO validate timestamp!
     %% TODO some more scalable solution
-    AllowedDomains = application:get_env(?APP, tls_allowed_domains, []),
-    lists:member(Domain, AllowedDomains)
-        orelse error({protocol_error, tls_sni_domain_not_allowed, Domain});
+    case application:get_env(?APP, tls_allowed_domains, any) of
+        any ->
+            %% No limits
+            true;
+        AllowedDomains ->
+            lists:member(Domain, AllowedDomains)
+                orelse error({protocol_error, tls_sni_domain_not_allowed, Domain})
+    end;
 check_tls_access(_, Ip, Meta) ->
     error({protocol_error, tls_no_sni, {Ip, Meta}}).
 
diff --git a/src/mtproto_proxy.app.src b/src/mtproto_proxy.app.src
index 1240ead..185ecc1 100644
--- a/src/mtproto_proxy.app.src
+++ b/src/mtproto_proxy.app.src
@@ -60,7 +60,9 @@
 
         %% Which domains to allow in TLS SNI
         %% XXX: this option is experimental and will be removed later!
-        {tls_allowed_domains, [<<"en.wikipedia.org">>]},
+        %% Can be set to `any' to allow any domains.
+        %% {tls_allowed_domains, any},
+        {tls_allowed_domains, [<<"en.wikipedia.org">>, <<"s3.amazonaws.com">>]},
 
         {init_dc_connections, 2},
         {clients_per_dc_connection, 300},
diff --git a/src/mtproto_proxy_app.erl b/src/mtproto_proxy_app.erl
index 8140ae8..c56dbd9 100644
--- a/src/mtproto_proxy_app.erl
+++ b/src/mtproto_proxy_app.erl
@@ -173,7 +173,11 @@ build_urls(Host, Port, Secret, Protocols) ->
     lists:map(
       fun(mtp_fake_tls) ->
               %% Print just for 1st domain as example
-              {ok, [Domain | _]} = application:get_env(?APP, tls_allowed_domains),
+              Domain = case application:get_env(?APP, tls_allowed_domains) of
+                           {ok, [Domain0 | _]} -> Domain0;
+                           _ ->
+                               <<"en.wikipedia.org">>
+                       end,
               ProtoSecret = mtp_fake_tls:format_secret(Secret, Domain),
               MkUrl(ProtoSecret);
          (mtp_secure) ->