openarc-docker

A Docker image for OpenARC, providing ARC (Authenticated Received Chain) message signing and verification. Built on CentOS Stream 8.

Configuration

Copy example.env to .env and adjust the values:

Variable	Default	Description
`DOMAIN`	(required)	The domain that sends email
`KEYFILE`	`DKIM.key`	Name of the bind-mounted key file
`SELECTOR`	`dkim`	DKIM DNS selector (without `._domainkey`)
`SIG_ALG`	`rsa-sha256`	Signature algorithm for ARC signing

Create your .env file:

cp example.env .env
# edit .env with your values

Run the container:

docker build -t openarc .
docker run -d \
  --env-file .env \
  -v $(pwd)/DKIM.key:/app/DKIM.key:ro \
  -p 8894:8894 \
  openarc

OpenARC listens on port 8894 and runs in sign+verify (sv) mode. Connect your MTA's milter configuration to this port.