Add WebTunnel Integration

This is a squashed commit that includes:
Replace cgo Condition in Go Config
Include WebTunnel README in Browser
Include WebTunnel into Tor Expert Bundle
Add WebTunnel to default torrc
Add WebTunnel project

Their original form is available at:
https://gitlab.torproject.org/shelikhoo/tor-browser-build-2/-/commits/dev-webtunnel-rebased-backup

See also: tpo/applications/tor-browser-build!595

projects/browser/Bundle-Data/PTConfigs/linux/torrc-defaults-appendix

@@ -3,3 +3,6 @@ ClientTransportPlugin meek_lite,obfs2,obfs3,obfs4,scramblesuit exec ./TorBrowser
 
 ## snowflake configuration
 ClientTransportPlugin snowflake exec ./TorBrowser/Tor/PluggableTransports/snowflake-client
+
+## webtunnel configuration
+ClientTransportPlugin webtunnel exec ./TorBrowser/Tor/PluggableTransports/webtunnel-client

projects/browser/Bundle-Data/PTConfigs/mac/torrc-defaults-appendix

@@ -3,3 +3,6 @@ ClientTransportPlugin meek_lite,obfs2,obfs3,obfs4,scramblesuit exec PluggableTra
 
 ## snowflake configuration
 ClientTransportPlugin snowflake exec PluggableTransports/snowflake-client
+
+## webtunnel configuration
+ClientTransportPlugin webtunnel exec PluggableTransports/webtunnel-client

projects/browser/Bundle-Data/PTConfigs/windows/torrc-defaults-appendix

@@ -3,3 +3,6 @@ ClientTransportPlugin meek_lite,obfs2,obfs3,obfs4,scramblesuit exec TorBrowser\T
 
 ## snowflake configuration
 ClientTransportPlugin snowflake exec TorBrowser\Tor\PluggableTransports\snowflake-client.exe
+
+## webtunnel configuration
+ClientTransportPlugin webtunnel exec TorBrowser\Tor\PluggableTransports\webtunnel-client.exe

projects/browser/build

@@ -88,10 +88,14 @@ mv [% c('input_files_by_name/noscript') %] "$TBDIR/$EXTSPATH/{73a6fe31-595d-460b
     rm -f aarch64/tor/pluggable_transports/bridges_list.*.txt
   [% END -%]
 
-  # Snowflake's README is the only documentation shipped in tor-expert-bundle
+  # Snowflake's README is a documentation shipped in tor-expert-bundle
   mkdir -p "$TBDIR/$DOCSPATH/snowflake" [% IF c("var/macos_universal") %]"$TBDIR_AARCH64/$DOCSPATH/snowflake"[% END %]
   mv_tbdir tor/pluggable_transports/README.SNOWFLAKE.md "$DOCSPATH/snowflake/README.md"
   
+  # WebTunnel's README is a documentation shipped in tor-expert-bundle
+  mkdir -p "$TBDIR/$DOCSPATH/webtunnel" [% IF c("var/macos_universal") %]"$TBDIR_AARCH64/$DOCSPATH/webtunnel"[% END %]
+  mv_tbdir tor/pluggable_transports/README.WEBTUNNEL.md "$DOCSPATH/webtunnel/README.md"
+
   # Move the PTs to where TB expects them
   mkdir -p "$TBDIR/$TORBINPATH" [% IF c("var/macos_universal") %]"$TBDIR_AARCH64/$TORBINPATH"[% END %]
   mv_tbdir tor/pluggable_transports "$TORBINPATH/PluggableTransports"

projects/go/config

@@ -26,7 +26,7 @@ var:
       export CGO_LDFLAGS_ALLOW="-z|noexecstack"
       export CGO_LDFLAGS="-z noexecstack"
     [% END -%]
-    [% IF c("var/linux-i686") -%]
+    [% IF c("var/cgo") -%]
       export CGO_ENABLED=1
     [% END -%]
     export GOTMPDIR=/var/tmp/build/go-tmp

projects/tor-expert-bundle/build

@@ -11,6 +11,7 @@ mkdir pluggable_transports && cd pluggable_transports
 
 tar -xkf $rootdir/[% c('input_files_by_name/obfs4') %]
 tar -xkf $rootdir/[% c('input_files_by_name/snowflake') %]
+tar -xkf $rootdir/[% c('input_files_by_name/webtunnel') %]
 
 # copy in bridge lines for each pluggable transport
 mv $rootdir/bridges_list.obfs4.txt .

projects/tor-expert-bundle/config

@@ -13,6 +13,8 @@ input_files:
     project: obfs4
   - name: snowflake
     project: snowflake
+  - project: webtunnel
+    name: webtunnel
   - filename: bridges_list.obfs4.txt
   - filename: bridges_list.meek-azure.txt
   - filename: bridges_list.snowflake.txt
\ No newline at end of file

projects/webtunnel/build

+#!/bin/bash
+[% c("var/set_default_env") -%]
+[% pc('go', 'var/setup', { go_tarfile => c('input_files_by_name/go') }) %]
+distdir=/var/tmp/dist/[% project %]
+mkdir -p $distdir
+
+[% IF c("var/android") -%]
+  [% pc(c('var/compiler'), 'var/setup', { compiler_tarfile => c('input_files_by_name/' _ c('var/compiler')) }) %]
+  # We need to explicitly set CGO_ENABLED with Go 1.13.x as the Android build
+  # breaks otherwise.
+  export CGO_ENABLED=1
+[% END -%]
+
+tar -C /var/tmp/dist -xf [% c('input_files_by_name/goptlib') %]
+
+mkdir -p /var/tmp/build
+tar -C /var/tmp/build -xf [% project %]-[% c('version') %].tar.gz
+cd /var/tmp/build/[% project %]-[% c('version') %]
+
+mkdir -p "$GOPATH/src/gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/webtunnel.git"
+ln -sf "$PWD" "$GOPATH/src/gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/webtunnel"
+
+cd main/client
+go build -ldflags '-s'
+cp -a client[% IF c("var/windows") %].exe[% END %] $distdir/webtunnel-client[% IF c("var/windows") %].exe[% END %]
+
+cd /var/tmp/build/[% project %]-[% c('version') %]
+cp -a README.md $distdir/README.WEBTUNNEL.md
+
+cd $distdir
+[% c('tar', {
+        tar_src => [ '.' ],
+        tar_args => '-czf ' _ dest_dir _ '/' _ c('filename'),
+    }) %]

projects/webtunnel/config

+# vim: filetype=yaml sw=2
+version: '[% c("abbrev") %]'
+git_url: https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/webtunnel.git
+git_hash: 2ecf64381bad8a5db45c5871dcad7d12831dca69
+filename: '[% project %]-[% c("version") %]-[% c("var/osname") %]-[% c("var/build_id") %].tar.gz'
+container:
+  use_container: 1
+
+input_files:
+  - project: container-image
+  - name: go
+    project: go
+  - name: goptlib
+    project: goptlib
+  - name: '[% c("var/compiler") %]'
+    project: '[% c("var/compiler") %]'
+    enable: '[% c("var/android") %]'