SMART/FHIR proxy server and app launcher

Launcher for SMART apps

OIDC Keys generation

To generate new private and public keys make sure you have openssl (comes pre-installed with the Mac), cd to the project root and execute:

npm run cert

Then re-start the server and it will use the new keys.

OIDC Token verification

If you want to verify the tokens follow this procedure:

1. Point your server to /.well-known/openid-configuration/. This should render a JSON with a link to another file like this:

{
    "jwks_uri": "http://localhost:8443/keys"
}

2. Follow that link and it should return an array with one or more JWK keys like this:

{
    "keys": [
        {
            "alg": "RS256",
            "kid": "9c37bf73343adb93920a7ae80260b0e57684551e",
            "use": "sig",
            "kty": "RSA",
            // ...
        }
    ]
}

3. Use the first key and extract the public key out of it. To do so, you can use tools like https://github.com/Brightspace/node-jwk-to-pem. Something like this would be the basic example:

const JWK_KEY = getJwkKeySomehow(); // as described above
const ID_TOKEN = getIdTokenSomehow();
try {
    jwt.verify(ID_TOKEN, jwkToPem(JWK_KEY), { algorithms: ["RS256"] });
} catch (ex) {
    // Cannot verify the token...
}

Libraries like https://www.npmjs.com/package/jwks-rsa can be used to automate this process.

Notes about jwt.io

People often use https://jwt.io/ to generate and validate tokens. However, it seems that the RS256 signature verification feature expects you to paste x.509 formatted public key or certificate and does not work with PEM-encoded PKCS#1 public keys. For that reason, if you want to manually verify your token at https://jwt.io/, you will need to provide the original x.509 version of the public key that you can find at the /public_key endpoint of the server.

Using Docker

docker run -t -p 9009:80 smartonfhir/smart-launcher:latest