release v4.4.0

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 2.5.0 to 2.6.1.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](https://github.com/docker/build-push-action/compare/v2.5.0...v2.6.1)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/dependabot.yml

@@ -0,0 +1,18 @@
+# sync with https://github.com/fphammerle/docker-onion-service/blob/master/.github/dependabot.yml
+
+version: 2
+
+updates:
+- package-ecosystem: docker
+  directory: /
+  schedule:
+    interval: weekly
+    day: friday
+- package-ecosystem: github-actions
+  directory: /
+  # > YAML aliases are not supported
+  schedule:
+    interval: weekly
+    day: friday
+
+# https://docs.github.com/en/free-pro-team@latest/github/administering-a-repository/configuration-options-for-dependency-updates

.github/workflows/container-image.yml

@@ -0,0 +1,26 @@
+# sync with https://github.com/fphammerle/docker-onion-service/blob/master/.github/workflows/container-image.yml
+
+name: container image
+
+on:
+  push:
+  pull_request:
+  schedule:
+  - cron: '0 20 * * 5'
+
+jobs:
+  docker-build:
+    runs-on: ubuntu-20.04
+    steps:
+    - uses: docker/setup-qemu-action@v1.2.0
+    - uses: docker/setup-buildx-action@v1.4.1
+    # > By default, this action uses the Git context so you don't need to use
+    # > the actions/checkout action to checkout the repository because this
+    # > will be done directly by buildkit. [...]
+    # > any file mutation in the steps that precede [...] will be ignored
+    # https://github.com/marketplace/actions/build-and-push-docker-images
+    - uses: docker/build-push-action@v2.6.1
+      with:
+        platforms: |
+          linux/amd64
+          linux/arm/v7

CHANGELOG.md

@@ -4,14 +4,95 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Unreleased
+## [Unreleased]
+
+## [4.4.0] - 2021-07-07
+### Added
+- added ability to exclude exit nodes via `EXCLUDE_EXIT_NODES` environment variable
+
+## [4.3.1] - 2021-05-15
 ### Fixed
-- upgrade default tor version: 0.4.1.6 -> 0.4.1.7
-  (non-breaking, fixes only, https://gitweb.torproject.org/tor.git/plain/ChangeLog)
+- create prerouting chain if not already created by container runtime
+  (fixes dns proxy with direct routing & transparent proxy on some hosts)
+
+## [4.3.0] - 2021-05-07
+### Added
+- when running entrypoint as `uid=0`:
+  add `nftables` rule forwarding udp dns requests (port 53) to tor
+  (alternative for less flexible `docker run --publish 53:9053 …`)
+
+## [4.2.0] - 2021-04-30
+### Added
+- when running entrypoint as `uid=0`:
+  add `nftables` rule redirecting `tcp` traffic to transparent proxy
+
+## [4.1.0] - 2021-03-03
+### Added
+- enabled transparent proxy, listening on port `9040` (requires netfilter rules)
+- image labels:
+  - `org.opencontainers.image.revision` (git commit hash via build arg)
+  - `org.opencontainers.image.source` (repo url)
+  - `org.opencontainers.image.title`
+
+## [4.0.0] - 2021-01-01
+### Changed
+- healthcheck: replace periodic http requests with probing
+  [network-liveness](https://gitweb.torproject.org/torspec.git/tree/control-spec.txt)
+  to improve privacy (keeping dns requests for faster updates)
+- changed log level of `control` domain to `warn`
+  (to avoid log spam by healthcheck connecting to control listener)
+- added message domains to log messages
+
+### Removed
+- `curl`
+- `bind-tools` package including `dig`
+
+## [3.0.0] - 2020-10-03
+### Added
+- create mount point at `/var/lib/tor`
+  to be able to make container's root filesystem read-only
+
+### Changed
+- moved tor's data directory from `/home/onion/.tor` to `/var/lib/tor`
+- run `tor` as user `tor` (uid=100) instead of `onion` (uid=101)
+- docker-compose & ansible-playbook: read-only root filesystem
+
+### Fixed
+- ansible-playbook: drop capabilities
+
+## [2.1.0] - 2020-09-27
+### Added
+- enable [tor control](https://gitweb.torproject.org/torspec.git/tree/control-spec.txt)
+  listener on port `9051`
+  (listening on loopback device only)
+
+## [2.0.0] - 2020-03-24
+### Changed
+- changed DNS port from 53 to 9053
+- run as unprivileged user
+
+## [1.1.1] - 2020-03-21
+### Fixed
+- fix invalid torrc path
+
+## [1.1.0] - 2020-03-21
+### Added
+- change `SocksTimeout` option by setting `$SOCKS_TIMEOUT_SECONDS`
 
 ## [1.0.0] - 2019-10-12
 ### Added
-- Tor Socks5 & DNS proxy
+- tor socks5 & DNS proxy
 
-[Unreleased]: https://github.com/fphammerle/docker-tor-proxy/compare/1.0.0...HEAD
+[Unreleased]: https://github.com/fphammerle/docker-tor-proxy/compare/v4.4.0...HEAD
+[4.4.0]: https://github.com/fphammerle/docker-tor-proxy/compare/v4.3.1...v4.4.0
+[4.3.1]: https://github.com/fphammerle/docker-tor-proxy/compare/v4.3.0...v4.3.1
+[4.3.0]: https://github.com/fphammerle/docker-tor-proxy/compare/v4.2.0...v4.3.0
+[4.2.0]: https://github.com/fphammerle/docker-tor-proxy/compare/v4.1.0...v4.2.0
+[4.1.0]: https://github.com/fphammerle/docker-tor-proxy/compare/v4.0.0...v4.1.0
+[4.0.0]: https://github.com/fphammerle/docker-tor-proxy/compare/v3.0.0...v4.0.0
+[3.0.0]: https://github.com/fphammerle/docker-tor-proxy/compare/v2.1.0...v3.0.0
+[2.1.0]: https://github.com/fphammerle/docker-tor-proxy/compare/v2.0.0...v2.1.0
+[2.0.0]: https://github.com/fphammerle/docker-tor-proxy/compare/v1.1.1...v2.0.0
+[1.1.1]: https://github.com/fphammerle/docker-tor-proxy/compare/v1.1.0...v1.1.1
+[1.1.0]: https://github.com/fphammerle/docker-tor-proxy/compare/1.0.0...v1.1.0
 [1.0.0]: https://github.com/fphammerle/docker-tor-proxy/releases/tag/1.0.0

Dockerfile

@@ -1,26 +1,41 @@
-FROM alpine:3.11
+FROM docker.io/alpine:3.14.0
 
-ARG CURL_PACKAGE_VERSION=7.67.0-r0
-ARG BIND_TOOLS_PACKAGE_VERSION=9.14.8-r5
-ARG TOR_PACKAGE_VERSION=0.4.1.7-r0
-RUN adduser -S onion \
-    && apk add --no-cache \
-        curl=$CURL_PACKAGE_VERSION \
-        bind-tools=$BIND_TOOLS_PACKAGE_VERSION `# dig` \
+# nftables + dependencies add 2.3MB to image
+ARG TOR_PACKAGE_VERSION=0.4.5.9-r0
+ARG NFTABLES_PACKAGE_VERSION=0.9.9-r0
+RUN apk add --no-cache \
+        nftables=$NFTABLES_PACKAGE_VERSION \
         tor=$TOR_PACKAGE_VERSION
+VOLUME /var/lib/tor
 
-# RUN apk add --no-cache man less \
-#     && apk add --no-cache tor-doc=$TOR_PACKAGE_VERSION \
-#        --repository $TOR_PACKAGE_REPOSITORY
-# ENV PAGER=less
+#RUN apk add --no-cache \
+#        less \
+#        man-db \
+#        strace \
+#        tor-doc=$TOR_PACKAGE_VERSION
+#ENV PAGER=less
 
 EXPOSE 9050/tcp
-EXPOSE 53/udp
-COPY torrc /etc/tor/torrc
+EXPOSE 9053/udp
+COPY torrc.template entrypoint.sh /
+RUN chmod -c a+rX /torrc.template /entrypoint.sh
+ENV SOCKS_TIMEOUT_SECONDS=
+ENTRYPOINT ["/entrypoint.sh"]
 
-CMD ["tor"]
+# entrypoint.sh drops privileges after configuring nftables for transparent proxy
+#USER tor
+CMD ["tor", "-f", "/tmp/torrc"]
 
+# keeping dns requests as network-liveness is too optimistic
+# https://gitweb.torproject.org/torspec.git/tree/control-spec.txt
 HEALTHCHECK CMD \
-    curl --silent --socks5 localhost:9050 https://google.com > /dev/null \
-    && [ ! -z "$(dig +notcp +short one.one.one.one @localhost)" ] \
+    printf "AUTHENTICATE\nGETINFO network-liveness\nQUIT\n" | nc localhost 9051 \
+        | grep -q network-liveness=up \
+    && nslookup -port=9053 google.com localhost | grep -v NXDOMAIN | grep -q google \
     || exit 1
+
+# https://github.com/opencontainers/image-spec/blob/v1.0.1/annotations.md
+ARG REVISION=
+LABEL org.opencontainers.image.title="tor socks, dns & transparent proxy" \
+    org.opencontainers.image.source="https://github.com/fphammerle/docker-tor-proxy" \
+    org.opencontainers.image.revision="$REVISION"

Makefile

@@ -0,0 +1,32 @@
+IMAGE_NAME := docker.io/fphammerle/tor-proxy
+PROJECT_VERSION = $(shell git describe --match=v* --abbrev=0 --dirty | sed -e 's/^v//')
+TOR_PACKAGE_VERSION = $(shell grep -Po 'TOR_PACKAGE_VERSION=\K.+' Dockerfile | tr -d -)
+ARCH = $(shell arch)
+# architecture[arm_variant]
+# https://github.com/opencontainers/image-spec/blob/v1.0.1/image-index.md#image-index-property-descriptions
+IMAGE_TAG_ARCH_aarch64 = arm64
+IMAGE_TAG_ARCH_armv6l = armv6
+IMAGE_TAG_ARCH_armv7l = armv7
+IMAGE_TAG_ARCH_x86_64 = amd64
+IMAGE_TAG_ARCH = ${IMAGE_TAG_ARCH_${ARCH}}
+IMAGE_TAG = ${PROJECT_VERSION}-tor${TOR_PACKAGE_VERSION}-${IMAGE_TAG_ARCH}
+BUILD_PARAMS = --tag="${IMAGE_NAME}:${IMAGE_TAG}" \
+	--build-arg=REVISION="$(shell git rev-parse HEAD)"
+
+.PHONY: worktree-clean docker-build podman-build docker-push
+
+worktree-clean:
+	git diff --exit-code
+	git diff --staged --exit-code
+
+docker-build: worktree-clean
+	sudo docker build ${BUILD_PARAMS} .
+
+podman-build: worktree-clean
+	# --format=oci (default) not fully supported by hub.docker.com
+	# https://github.com/docker/hub-feedback/issues/1871#issuecomment-748924149
+	podman build --format=docker ${BUILD_PARAMS} .
+
+docker-push: docker-build
+	sudo docker push "${IMAGE_NAME}:${IMAGE_TAG}"
+	@echo git tag --sign --message '$(shell sudo docker image inspect --format '{{join .RepoDigests "\n"}}' "${IMAGE_NAME}:${IMAGE_TAG}")' docker/${IMAGE_TAG} $(shell git rev-parse HEAD)

README.md

@@ -1,22 +1,23 @@
 # docker: tor socks & dns proxy 🌐 🐳
 
-docker hub: https://hub.docker.com/r/fphammerle/tor-proxy
+Docker Hub: https://hub.docker.com/r/fphammerle/tor-proxy
 
-signed tags: https://github.com/fphammerle/docker-tor-proxy/tags
+Signed image tags: https://github.com/fphammerle/docker-tor-proxy/tags
 
 ```sh
-$ docker run --rm --name tor-proxy \
+$ sudo docker run --rm --name tor_proxy \
     -p 127.0.0.1:9050:9050/tcp \
-    -p 127.0.0.1:53:53/udp \
+    -p 127.0.0.1:53:9053/udp \
     fphammerle/tor-proxy
 ```
 
 or after cloning the repository 🐙
 ```sh
-$ docker-compose up
+$ sudo docker-compose up
 ```
 
-test proxies:
+### Test Proxies
+
 ```sh
 $ curl --proxy socks5h://localhost:9050 ipinfo.io
 $ torsocks wget -O - ipinfo.io
@@ -27,7 +28,51 @@ $ ssh -o 'ProxyCommand nc -x localhost:9050 -v %h %p' abcdefghi.onion
 $ chromium-browser --proxy-server=socks5://localhost:9050 ipinfo.io
 ```
 
-isolate:
+### Read-only Root Filesystem
+
+Optionally add
 ```sh
-iptables -A OUTPUT ! -o lo -j REJECT --reject-with icmp-admin-prohibited
+$ sudo docker run --read-only -v tor_proxy_data:/var/lib/tor --tmpfs /tmp:rw,size=4k` …
+```
+to make the container's root filesystem read-only.
+
+### Isolate Host
+
+```sh
+sudo iptables -A OUTPUT ! -o lo -j REJECT --reject-with icmp-admin-prohibited
+```
+
+### Change `SocksTimeout` Option
+
+```sh
+$ sudo docker run -e SOCKS_TIMEOUT_SECONDS=60 …
+```
+
+### Exclude Exit Nodes
+
+```sh
+$ sudo docker run -e EXCLUDE_EXIT_NODES=1.2.3.4,1.2.3.5 …
+```
+
+### Show Circuits
+
+```sh
+$ printf 'AUTHENTICATE\nGETINFO circuit-status\nQUIT\n' \
+    | sudo docker exec -i tor_proxy nc localhost 9051
+```
+relay search: https://metrics.torproject.org/rs.html
+
+or using [onioncircuits](https://gitlab.tails.boum.org/tails/onioncircuits) ([debian repo](https://salsa.debian.org/pkg-privacy-team/onioncircuits)):
+```sh
+$ sudo apt-get install --no-install-recommends onioncircuits
+$ sudo nsenter --target "$(sudo docker inspect --format='{{.State.Pid}}' tor_proxy)" --net \
+    sudo -u $USER onioncircuits
+```
+
+### Troubleshooting
+
+Disable `SafeLogging` (temporarily) to log IP addresses instead of `[scrubbed]`:
+```
+$ printf 'AUTHENTICATE\nSETCONF SafeLogging=0\nGETCONF SafeLogging\nQUIT\n' \
+    | sudo docker exec -i tor_proxy nc localhost 9051
 ```

ansible-playbook.yml

@@ -7,16 +7,30 @@
         com.docker.network.bridge.name: tor
   - docker_container:
       name: tor_proxy
-      # 1.0.0-tor0.4.1.6-amd64
-      image: fphammerle/tor-proxy@sha256:ad55d07b1b21c35fa044dc3e1ea6c7d8494f39eb89491ddad35c245340f7cd4b
+      # object 9d8903fbee049c379537c5e291cfa88f57b049f2
+      # tag docker/3.0.0-tor0.4.3.5-amd64
+      image: docker.io/fphammerle/tor-proxy@sha256:501c5b5432156f25ecfce9e48ebfe0827f7702a1d32206af79f256cc94487a0f
+      mounts:
+      - type: volume
+        source: tor_proxy_data
+        target: /var/lib/tor
+        read_only: no
+      - type: tmpfs
+        target: /tmp # torrc
+        # nosuid,nodev,noexec added by default
+        tmpfs_mode: '1777'
+        tmpfs_size: 4k
+      read_only: yes
       networks:
       - name: tor_proxy_network
       purge_networks: yes
       ports:
       - '127.0.0.1:9050:9050/tcp'
-      - '127.0.0.1:53:53/udp'
-      restart_policy: unless-stopped
+      - '127.0.0.1:53:9053/udp'
+      cap_drop: [ALL]
+      security_opts: [no-new-privileges]
       memory: 128M
+      restart_policy: unless-stopped
   - iptables:
       action: append
       table: filter

docker-compose.yml

@@ -1,15 +1,36 @@
-version: '2.2'
+version: '2.3'
+
+volumes:
+  data:
 
 services:
   tor_proxy:
     build: .
     image: fphammerle/tor-proxy
+    environment:
+      SOCKS_TIMEOUT_SECONDS: 30
+      #EXCLUDE_EXIT_NODES: '{xx},{yy},1.2.3.4,128.0.0.0/1'
+    volumes:
+    - type: volume
+      source: data
+      target: /var/lib/tor
+      read_only: no
+    - type: tmpfs
+      target: /tmp # torrc
+      tmpfs:
+        # nosuid,nodev,noexec added by default
+        mode: '1777'
+        size: 5k
+    read_only: yes
     ports:
     - '127.0.0.1:9050:9050/tcp'
-    - '127.0.0.1:53:53/udp'
-    security_opt: ['no-new-privileges']
-    restart: unless-stopped
+    - '127.0.0.1:53:9053/udp'
+    cap_drop: [ALL]
+    # entrypoint.sh drops privileges after configuring nftables for transparent proxy
+    cap_add: [NET_ADMIN, SETUID, SETGID]
+    security_opt: [no-new-privileges]
     cpus: 0.5
     mem_limit: 128m
+    restart: unless-stopped
 
 # https://docs.docker.com/compose/compose-file/compose-file-v2/

entrypoint.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+
+set -e
+
+if [ "$(id -u)" -eq 0 ]; then
+    nft add chain ip nat PREROUTING { type nat hook prerouting priority dstnat \; } || true
+    nft add rule ip nat PREROUTING ip protocol tcp fib daddr type != local counter redirect to :9040 \
+        || echo 'warning: failed to configure nftables for transparent proxy (missing CAP_NET_ADMIN?)'
+    nft add rule ip nat PREROUTING fib daddr type local udp dport 53 counter redirect to :9053 \
+        || echo 'warning: failed to configure nftables for DNS proxy' \
+                '(alternative for less flexible `docker run --publish 53:9053 ...`)'
+    exec su -s /bin/sh tor -- "$0" "$@"
+fi
+
+# default: 120 sec
+# https://github.com/torproject/tor/blob/tor-0.4.1.7/src/core/or/connection_edge.c#L1099
+if [ -z "$SOCKS_TIMEOUT_SECONDS" ]; then
+    sed -e '/{socks_timeout_seconds}/d' /torrc.template > /tmp/torrc
+else
+    sed -e "s/{socks_timeout_seconds}/$SOCKS_TIMEOUT_SECONDS/" /torrc.template > /tmp/torrc
+fi
+
+if [ -z "$EXCLUDE_EXIT_NODES" ]; then
+    sed --in-place -e '/{exclude_exit_nodes}/d' /tmp/torrc
+else
+    sed --in-place -e "s#{exclude_exit_nodes}#$EXCLUDE_EXIT_NODES#" /tmp/torrc
+fi
+
+exec "$@"

tor-changelog.url

@@ -0,0 +1 @@
+https://gitweb.torproject.org/tor.git/plain/ChangeLog

torrc

@@ -1,7 +0,0 @@
-Log notice stdout
-
-SocksPort 0.0.0.0:9050
-DNSPort 0.0.0.0:53
-
-# try to
-HardwareAccel 1

torrc.template

@@ -0,0 +1,32 @@
+# https://www.torproject.org/docs/tor-manual.html.en
+
+# hide healthchecks:
+# > [notice] {CONTROL} New control connection opened from 127.0.0.1.
+Log [~control]notice warn stdout
+LogMessageDomains 1
+
+# default: ~/.tor
+DataDirectory /var/lib/tor
+
+# https://gitweb.torproject.org/torspec.git/tree/control-spec.txt
+ControlPort localhost:9051
+
+DNSPort 0.0.0.0:9053
+
+SocksPort 0.0.0.0:9050
+SocksTimeout {socks_timeout_seconds}
+
+# requires netfilter rules
+# socks5 with auth-based circuit isolation (tor browser, torsocks --isolate) should be preferred
+# cave: IsolateDestAddr & IsolateDestPort are not enabled
+# https://gitlab.torproject.org/legacy/trac/-/wikis/doc/TransparentProxy
+# https://github.com/epidemics-scepticism/writing/blob/b6733379d653b30771d578ace04c262600345122/misconception.md#transparent-proxying-lacks-context
+# https://lists.torproject.org/pipermail/tor-talk/2014-March/032507.html
+# https://gitweb.torproject.org/tor.git/tree/src/or/connection_edge.c?id=6285d9bdcf7f210c56abd25f75133e30d05a7473#n1423
+# https://github.com/mitmproxy/mitmproxy/blob/v6.0.2/mitmproxy/platform/linux.py#L27
+TransPort 0.0.0.0:9040 IsolateClientAddr IsolateClientProtocol
+
+ExcludeExitNodes {exclude_exit_nodes}
+
+# try to
+HardwareAccel 1