abiosoft / caddy-hmac

Caddy v2 hmac signature validation middleware

caddy-hmac

Caddy v2 hmac middleware

Installation

xcaddy build v2.0.0 \
    --with github.com/abiosoft/caddy-hmac

Usage

hmac computes the hash of the request body as a {hmac.signature} placeholder for other matchers and handlers.

Caddyfile

hmac [<name>] <algorithm> <secret>

• name - [optional] if set, names the signature and available as {hmac.name.signature}.
• algorithm - hash algorithm to use. Can be one of sha1, sha256, md5.
• secret - the hmac secret key.

Example

Run a command after validating a Github webhook secured with a secret.

@github {
    path /webhook
    header_regexp X-Hub-Signature "[a-z0-9]+\=([a-z0-9]+)"
}
@hmac {
    expression {hmac.signature} == {http.regexp.1}
}
route @github {
    hmac sha1 {$GITHUB_WEBHOOK_SECRET}
    exec @hmac git pull origin master
}

JSON

hmac can be part of any route as an handler

{
  ...
  "routes": [
    {
      "handle": [
        {
          // required to indicate the handler
          "handler": "hmac",
          // [optional] if set, names the sigurature to be referenced
          // as {hmac.name.signature}.
          "name": "",
          // the algorithm to use. can be sha1, sha256, md5
          "algorithm": "sha1",
          // hmac secret
          "secret": "some secrets"
        }
      ]
    },
    ...
  ]
  ...
}

License

Apache 2