OAuth 2 library for HAProxy

This is a Lua library for HAProxy that will verify OAuth 2 JWT tokens.

Install

The jwtverify.lua file has these dependencies:

• base64 (included in this repository)
• lua-json
• luaossl
• luasocket

Install like so:

git clone https://github.com/haproxytech/haproxy-lua-oauth.git
cd haproxy-lua-oauth
chmod +x ./install.sh
sudo ./install.sh luaoauth

This installs jwtverify.lua and its dependencies to /usr/local/share/lua/5.4/jwtverify.lua.

Usage

1. Sign up for an account with an OAuth token provider, such as https://auth0.com
2. Create a new API on the Auth0 website
3. Create a new "Machine to Machine Application" on the Auth0 website, optionally granting it "scopes"
4. Download the public key certificate for your application on the Auth0 website via Applications > My App > Settings > Show Advanced Settings > Certificates > Download Certificate. Auth0 signs tokens using this key. Convert it using openssl x509 -pubkey -noout -in ./mycert.pem > pubkey.pem.
5. Update the HAProxy configuration file by:
   • Copy haproxy-example.cfg to /etc/haproxy/haproxy.cfg and restart HAProxy via sudo systemctl restart haproxy
   • or run it from this directory via sudo haproxy -f ./haproxy-example.cfg
6. Get a JSON web token (JWT) from your authentication server by following the Quick Start on the Auth0 website, under the Applications tab, for your Machine to Machine application.
7. Make requests to your API and attach the JWT in the Authorization header. You should get a successful response.

Supported Signing Algorithms

• RS256
• HS256
• HS512

Support for multiple audiences

This library support specifying multiple audience values in the JWT token. They should be specified as a JSON array of strings. You can also accept multiple audience values in the OAUTH_AUDIENCE environment variable in the haproxy.cfg file. Separate each value with a space and surround it with double quotes:

setenv OAUTH_AUDIENCE "https://api.mywebsite.com https://api2.mywebsite.com"

Output variables

After calling http-request lua.jwtverify, you get access to variables for each of the claims in the token.

Examples

• var(txn.oauth.aud)
• var(txn.oauth.clientId)
• var(txn.oauth.iss)
• var(txn.oauth.scope)

For example, you could track rate limiting based on the clientId or set different rate limit thresholds based on the scope.

Example

Try it out using the Docker Compose.

1. Sign up for a free account at https://auth0.com/ and create a new API.

2. Give the API any name, such as "My OAuth Test" and set the identifier to "https://api.mywebsite.com".

3. Once created, go to the API's "Permissions" tab and add permissions (aka scopes) that grant users different levels of access. The colon syntax is just a personal style, and colons do not mean anything special.

   permission	description
   read:myapp	Read access to my app
   write:myapp	Write access to myapp

4. Now that you have an API defined in Auth0, add an application that is allowed to authenticate to it. Go to the "Applications" tab and add a new "Machine to Machine Application" and select the API you just created. Give it the "read:myapp" and "write:myapp"permissions (or only one or the other).

5. On the Settings page for the new application, go to Advanced Settings > Certificates and download the certificate in PEM format. HAProxy will validate the access tokens against this certificate, which was signed by the OAuth provider, Auth0.

6. Convert it first using openssl x509 -pubkey -noout -in ./mycert.pem > pubkey.pem and save pubkey.pem to /example/haproxy/pem/pubkey.pem.

7. Edit example/haproxy/haproxy.cfg:

   • replace the OAUTH_ISSUER variable in the global section with the Auth0 domain URL with your own, such as https://myaccount.auth0.com/.
   • replace the OAUTH_AUDIENCE variable with your API name in Auth0, such as "https://api.mywebsite.com".
   • replace the OAUTH_PUBKEY_PATH variable with the path to your PEM certificate. (also update the docker-compose file)

8. Create the environment with Docker Compose:

   $ docker compose -f docker-compose.ubuntu.example.yml build
   $ docker compose -f docker-compose.ubuntu.example.yml up

9. Get a JSON web token (JWT) from your authentication server by going to your application on the Auth0 website and following the Quick Start.

10. Make requests to https://localhost/api/myapp and attach the JWT in the Authorization header. You should get a successful response.

    $ curl --request GET \
      -k \
      --url https://localhost/api/myapp \
      --header 'authorization: Bearer eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCIsImtpZCI6IlJEVkNSVFZHTmpZNU5rVTJSVUV3TnpoRk56UkJRalU0TjBFeU5EWTNSRU01TWtaRFJqTkNNUSJ9.eyJpc3MiOiJodHRwczovL25pY2tyYW00NC5hdXRoMC5jb20vIiwic3ViIjoicm9DTHRDTlZycW0zNmVYTzJxcE84cjEzeFBmQno1NklAY2xpZW50cyIsImF1ZCI6Imh0dHBzOi8vYXBpLm15d2Vic2l0ZS5jb20iLCJpYXQiOjE2NDgzMTQ2NjAsImV4cCI6MTY0ODQwMTA2MCwiYXpwIjoicm9DTHRDTlZycW0zNmVYTzJxcE84cjEzeFBmQno1NkkiLCJzY29wZSI6InJlYWQ6bXlhcHAgd3JpdGU6bXlhcHAiLCJndHkiOiJjbGllbnQtY3JlZGVudGlhbHMifQ.tEhJ0hKlqy9KRrS00we1Z6Y0CwGg5tAOmZ3qQYLYEwl1uymZ8OfJD9iGgPe5QhLJCTD-iwC18hWSwBMzNRLrjcjp1__hHOOyJRRoqekezS7NoHCMOKGLRis5EcfXMyb58yVxwrKIovHSRaEf0emg5NovQ2bdI3UpMThXnzlLhIH_SX5yRUtTxQ_qvO7xS9lZBNVYG9lYlNtU_Ih6dKCKNRUrMm8xsj2jLyR5_v3LcxgwzhK2VF01DZ9wyEgfHgs3H2AP6yJEZkmd9B1chO5Xf3f4klujsxvAb6RqTCwpGWmjRPY6SENkY2QX-PHOYVAc4zPvuauwx9Ojd4khA_KKfA'

    A successful response:

    ["robo-hamster","space-hamster","commando-hamster","pirate-hmaster"]