tlsproxy

README

TLS Termination Proxy

This repo contains a simple lightweight TLS termination proxy that uses letsencrypt to provide TLS encryption for any number of TCP servers and server names concurrently on the same port.

Its functionality is similar to an stunnel server, but without the need to configure and run certbot separately. It is intended to work smoothly with c2fmzq-server, and should also work with any TCP server.

Overview of features:

• Use Let's Encrypt automatically to get TLS certificates (http-01 & tls-alpn-01).
• Terminate TLS connections, and forward the data to any TCP server in plaintext.
• Terminate TLS connections, and forward the data to any TLS server. The data is encrypted in transit, but the proxy sees the plaintext.
• Terminate TCP connections, and forward the TLS connection to any TLS server (passthrough). The proxy doesn't see the plaintext.
• TLS client authentication & authorization (when the proxy terminates the TLS connections).
• Routing based on Server Name Indication (SNI), with optional default route when SNI isn't used.
• Simple round-robin load balancing between servers.
• Support for HTTP/2 and any ALPN protocol.
• Use the same TCP address (IPAddr:port) for any number of server names, e.g. xxx.xxx.xxx.xxx:443.

Example config:

# The HTTP address must be reachable from the internet via port 80 for the
# letsencrypt ACME http-01 challenge to work. If the httpAddr is empty, the
# proxy will only use tls-alpn-01 and tlsAddr must be reachable on port 443.
# See https://letsencrypt.org/docs/challenge-types/
httpAddr: ":10080"

# The proxy will receive TLS connections at this address and forward them to
# the backends.
tlsAddr: ":10443"

# Each backend has a list of server names (DNS names that clients connect to),
# and addresses (where to forward connections).
backends:
- serverNames: 
  - example.com
  - www.example.com
  addresses: 
  - 192.168.0.10:80
  - 192.168.0.11:80
  - 192.168.0.12:80

- serverNames:
  - other.example.com
  addresses:
  - 192.168.1.100:443
  mode: TLS
  insecureSkipVerify: true

- serverNames:
  - secure.example.com
  clientAuth: true
  clientCAs: |
    -----BEGIN CERTIFICATE-----
    .....
    -----END CERTIFICATE-----
  addresses:
  - 192.168.2.200:443
  mode: TLS
  forwardServerName: secure-internal.example.com

See the examples directory and internal/config.go for more details.

Run the proxy with:

go run ./proxy --config=config.yaml

Or, use the docker image, e.g.

docker run                      \
  --name=tlsproxy               \
  --user=1000:1000              \
  --restart=always              \
  --volume=${CONFIGDIR}:/config \
  --volume=${CACHEDIR}:/.cache  \
  --publish=80:10080            \
  --publish=443:10443           \
  c2fmzq/tlsproxy:latest

The proxy reads the config from ${CONFIGDIR}/config.yaml.

⚠ ${CACHEDIR} is used to store TLS secrets. It should only be accessible by the UID running tlsproxy.