openid-client

What is openid-client?

The openid-client package is a server-side library that allows Node.js applications to act as a Relying Party (RP) for any OpenID Connect (OIDC) compliant Identity Provider (IP). It provides functionality to discover OIDC providers, authenticate users, validate ID tokens, and securely perform token operations.

What are openid-client's main functionalities?

Discovery of OpenID Provider configuration

This feature allows the client to automatically discover the OpenID Provider's configuration using the issuer's URL. It simplifies the process of setting up the client by fetching the necessary endpoints and public keys.

const { Issuer } = require('openid-client');

(async () => {
  const googleIssuer = await Issuer.discover('https://accounts.google.com');
  console.log('Discovered issuer %s', googleIssuer.issuer);
})();

Client authentication with an OpenID Provider

This code sample demonstrates how to authenticate with an OpenID Provider by creating a client instance with the necessary credentials and generating an authorization URL for user redirection.

const { Issuer } = require('openid-client');

(async () => {
  const issuer = await Issuer.discover('https://example.com');
  const client = new issuer.Client({
    client_id: 'your-client-id',
    client_secret: 'your-client-secret',
    redirect_uris: ['https://your-callback-url/callback'],
    response_types: ['code']
  });

  const authorizationUrl = client.authorizationUrl({
    scope: 'openid email profile',
  });

  console.log('Authorization URL:', authorizationUrl);
})();

Handling authentication responses

This feature is used to handle the callback from the OpenID Provider after user authentication. It involves parsing the callback parameters, exchanging the authorization code for tokens, and validating the ID token.

const { Issuer, generators } = require('openid-client');

(async () => {
  const issuer = await Issuer.discover('https://example.com');
  const client = new issuer.Client({
    client_id: 'your-client-id',
    client_secret: 'your-client-secret',
    redirect_uris: ['https://your-callback-url/callback'],
    response_types: ['code']
  });

  const code_verifier = generators.codeVerifier();
  const code_challenge = generators.codeChallenge(code_verifier);

  const params = client.callbackParams('https://your-callback-url/callback?code=AUTH_CODE&state=STATE');
  const tokenSet = await client.callback('https://your-callback-url/callback', params, { code_verifier });

  console.log('Received and validated tokens %j', tokenSet);
  console.log('ID Token claims %j', tokenSet.claims());
})();

Token management

This code sample shows how to manage tokens, including how to exchange an authorization code for tokens and how to refresh tokens using a refresh token.

const { Issuer } = require('openid-client');

(async () => {
  const issuer = await Issuer.discover('https://example.com');
  const client = new issuer.Client({
    client_id: 'your-client-id',
    client_secret: 'your-client-secret'
  });

  const tokenSet = await client.grant({
    grant_type: 'authorization_code',
    code: 'AUTH_CODE',
    redirect_uri: 'https://your-callback-url/callback'
  });

  const refreshedTokenSet = await client.refresh(tokenSet.refresh_token);
  console.log('Refreshed tokens %j', refreshedTokenSet);
})();

Other packages similar to openid-client

passport

Passport is a widely used authentication middleware for Node.js. It supports a wide range of strategies, including OpenID Connect. Compared to openid-client, Passport provides a more general authentication solution that can be extended with various strategies for different authentication mechanisms.

oidc-provider

oidc-provider is a Node.js library that allows developers to implement their own OpenID Connect Provider. It is different from openid-client, which is designed to be used as a client for existing providers. oidc-provider is more suitable for those who want to create an identity provider rather than connect to one.

README

openid-client

openid-client is a server side OpenID Relying Party (RP, Client) implementation for Node.js, supports passport.

Table of Contents

• Implemented specs & features
• Certification
• Example
• Get started
• Usage
• Usage with passport
• Configuration

Implemented specs & features

The following client/RP features from OpenID Connect/OAuth2.0 specifications are implemented by openid-client.

• OpenID Connect Core 1.0 incorporating errata set 1
  • Authorization Callback
    • Authorization Code Flow
    • Implicit Flow
    • Hybrid Flow
  • UserInfo Request
  • Fetching Distributed Claims
  • Unpacking Aggregated Claims
  • Offline Access / Refresh Token Grant
  • Client Credentials Grant
  • Password Grant
  • Client Authentication
    • client_secret_basic
    • client_secret_post
    • client_secret_jwt
    • private_key_jwt
• OpenID Connect Discovery 1.0 incorporating errata set 1
  • Discovery of OpenID Provider (Issuer) Metadata
  • Discovery of OpenID Provider (Issuer) Metadata via user provided inputs (see #WebFinger)
• OpenID Connect Dynamic Client Registration 1.0 incorporating errata set 1
  • Dynamic Client Registration request
  • Client initialization via registration client uri
• RFC7009 - OAuth 2.0 Token revocation
  • Client Authenticated request to token revocation
• RFC7662 - OAuth 2.0 Token introspection
  • Client Authenticated request to token introspection

Certification

Filip Skokan has certified that openid-client conforms to the RP Basic, RP Implicit, RP Hybrid, RP Config and RP Dynamic profiles of the OpenID Connect™ protocol.

Example

Head over to the example folder to see the library in use. This example is deployed and configured to use an example OpenID Connect Provider here. The provider is using oidc-provider library.

Get started

On the off-chance you want to manage multiple clients for multiple issuers you need to first get an Issuer instance.

via Discovery (recommended)

const Issuer = require('openid-client').Issuer;
Issuer.discover('https://accounts.google.com') // => Promise
  .then(function (googleIssuer) {
    console.log('Discovered issuer %s', googleIssuer);
  });

manually

const Issuer = require('openid-client').Issuer;
const googleIssuer = new Issuer({
  issuer: 'https://accounts.google.com',
  authorization_endpoint: 'https://accounts.google.com/o/oauth2/v2/auth',
  token_endpoint: 'https://www.googleapis.com/oauth2/v4/token',
  userinfo_endpoint: 'https://www.googleapis.com/oauth2/v3/userinfo',
  jwks_uri: 'https://www.googleapis.com/oauth2/v3/certs',
}); // => Issuer
console.log('Set up issuer %s', googleIssuer);

Now you can create your Client.

manually (recommended)

You should provide at least the following metadata; client_id, client_secret. You can also provide id_token_signed_response_alg (defaults to RS256) and token_endpoint_auth_method (defaults to client_secret_basic).

const client = new googleIssuer.Client({
  client_id: 'zELcpfANLqY7Oqas',
  client_secret: 'TQV5U29k1gHibH5bx1layBo0OSAvAbRT3UYW3EWrSYBB5swxjVfWUa1BS8lqzxG/0v9wruMcrGadany3'
}, [keystore]); // => Client

keystore is an optional argument for instantiating a client with configured asymmetrical ID Token or UserInfo response encryption.

via registration client uri

Should your oidc provider have provided you with a registration client uri and registration access token you can also have the Client discovered.

googleIssuer.Client.fromUri(registration_client_uri, registration_access_token, [keystore]) // => Promise
  .then(function (client) {
    console.log('Discovered client %s', client);
  });

keystore is an optional argument for instantiating a client through registration client uri with configured asymmetrical ID Token or UserInfo response encryption.

Usage

Getting authorization url

client.authorizationUrl({
  redirect_uri: 'https://client.example.com/callback',
  scope: 'openid email',
}); // => String (URL)

You can also get HTML body of a self-submitting form to utilize POST to the authorization url with #authorizationPost method, same signature as #authorizationUrl.

client.authorizationPost({
  redirect_uri: 'https://client.example.com/callback',
  scope: 'openid email',
}); // => String (Valid HTML body)

Processing callback

client.authorizationCallback('https://client.example.com/callback', request.query) // => Promise
  .then(function (tokenSet) {
    console.log('received and validated tokens %j', tokenSet);
    console.log('validated id_token claims %j', tokenSet.claims);
  });

Processing callback with state, nonce or max_age check

const state = session.state;
const nonce = session.nonce;

client.authorizationCallback('https://client.example.com/callback', request.query, { state, nonce, max_age }) // => Promise
  .then(function (tokenSet) {
    console.log('received and validated tokens %j', tokenSet);
    console.log('validated id_token claims %j', tokenSet.claims);
  });

Handling multiple response modes

When handling multiple response modes with one single pass you can use #callbackParams to get the params object from the koa/express/node request object or a url string. (http.IncomingMessage). If form_post is your response_type you need to include a body parser prior.

client.callbackParams('https://client.example.com/cb?code=code'); // => { code: 'code' };
client.callbackParams('/cb?code=code'); // => { code: 'code' };

// example koa v2.x w/ koa-body
app.use(bodyParser({ patchNode: true }));
app.use(async function (ctx, next) {
  const params = client.callbackParams(ctx.request.req); // => parsed url query, url fragment or body object
  // ...
});

// example express w/ bodyParser
app.use(bodyParser.urlencoded({ extended: false }));
app.use(function (req, res, next) {
  const params = client.callbackParams(req); // => parsed url query, url fragment or body object
  // ...
});

Refreshing a token

client.refresh(refreshToken) // => Promise
  .then(function (tokenSet) {
    console.log('refreshed and validated tokens %j', tokenSet);
    console.log('refreshed id_token claims %j', tokenSet.claims);
  });

Tip: accepts TokenSet as well as direct refresh token values;

Revoke a token

client.revoke(token, [tokenTypeHint]) // => Promise
  .then(function (response) {
    console.log('revoked token %s', token, response);
  });

Introspect a token

client.introspect(token, [tokenTypeHint]) // => Promise
  .then(function (response) {
    console.log('token details %j', response);
  });

Fetching userinfo

client.userinfo(accessToken) // => Promise
  .then(function (userinfo) {
    console.log('userinfo %j', userinfo);
  });

Tip: accepts TokenSet as well as direct access token values;

via POST

client.userinfo(accessToken, { verb: 'post' }); // => Promise

with extra query/body payload

client.userinfo(accessToken, { params: { fields: 'email,ids_for_business' } }); // => Promise

auth via query

client.userinfo(accessToken, { via: 'query' }); // => Promise

auth via body

client.userinfo(accessToken, { verb: 'post', via: 'body' }); // => Promise

userinfo also handles (as long as you have the proper metadata configured) responses that are:

• signed
• signed and encrypted (nested JWT)
• just encrypted

Fetching Distributed Claims

let claims = {
  sub: 'userID',
  _claim_names: {
    credit_history: 'src1',
    email: 'src2',
  },
  _claim_sources: {
    src1: { endpoint: 'https://src1.example.com/claims', access_token: 'foobar' },
    src2: { endpoint: 'https://src2.example.com/claims' },
  },
};

client.fetchDistributedClaims(claims, { src2: 'bearer.for.src2' }) // => Promise
  .then(function (output) {
    console.log('claims %j', claims); // ! also modifies original input, does not create a copy
    console.log('output %j', output);
    // removes fetched names and sources and removes _claim_names and _claim_sources members if they
    // are empty
  });
  // when rejected the error will have a property 'src' with the source name it relates to

Unpacking Aggregated Claims

let claims = {
  sub: 'userID',
  _claim_names: {
    credit_history: 'src1',
    email: 'src2',
  },
  _claim_sources: {
    src1: { JWT: 'probably.a.jwt' },
    src2: { JWT: 'probably.another.jwt' },
  },
};

client.unpackAggregatedClaims(claims) // => Promise, autodiscovers JWT issuers, verifies signatures
  .then(function (output) {
    console.log('claims %j', claims); // ! also modifies original input, does not create a copy
    console.log('output %j', output);
    // removes fetched names and sources and removes _claim_names and _claim_sources members if they
    // are empty
  });
  // when rejected the error will have a property 'src' with the source name it relates to

Custom token endpoint grants

Use when the token endpoint also supports client_credentials or password grants;

client.grant({
  grant_type: 'client_credentials'
}); // => Promise

client.grant({
  grant_type: 'password',
  username: 'johndoe',
  password: 'A3ddj3w',
}); // => Promise

Registering new client (via Dynamic Registration)

const opts = { keystore, initialAccessToken }; // both optional
issuer.Client.register(metadata, [opts]) // => opts optional, Promise
  .then(function (client) {
    console.log('Registered client %s, %j', client, client.metadata);
  });

Generating a signed/encrypted Request Object

client.requestObject({ response_mode: 'form_post' }, {
  sign: client.request_object_signing_alg,
  encrypt: {
    alg: client.request_object_encryption_alg,
    enc: client.request_object_encryption_enc,
  }
}).then(function (request) {
  console.log('Nested signed and encrypted JWT Request Object %s', request)
});

WebFinger discovery

Issuer.webfinger(userInput) // => Promise
  .then(function (issuer) {
    console.log('Discovered issuer %s', issuer);
  });

Accepts, normalizes, discovers and validates the discovery of User Input using E-Mail, URL, acct, Hostname and Port syntaxes as described in Discovery 1.0.

Uses already discovered (cached) issuers where applicable.

TokenSet

authorizationCallback and refresh methods on a Client return TokenSet, when assigned an expires_in value a TokenSet calculates and assigns an expires_at with the corresponding unix time. It also comes with few helpers.

client.authorizationCallback(..., ...).then(function (tokenSet) {
  console.log('tokenSet#expires_at', tokenSet.expires_at);
  console.log('tokenSet#expires_in', tokenSet.expires_in);
  setTimeout(function () {
    console.log('tokenSet#expires_in', tokenSet.expires_in);
  }, 2000);
  console.log('tokenSet#expired()', tokenSet.expired());
  console.log('tokenSet#claims', tokenSet.claims);
});

Usage with passport

Once you have a Client instance, just pass it to the Strategy. Issuer is best discovered, Client passed properties manually or via an uri (see get-started).

Verify function is invoked with a TokenSet, userinfo only when requested, last argument is always the done function which you invoke once you found your user.

const Strategy = require('openid-client').Strategy;
const params = {
  // ... any authorization request parameters go here
  // client_id defaults to client.client_id
  // redirect_uri defaults to client.redirect_uris[0]
  // response type defaults to client.response_types[0], then 'code'
  // scope defaults to 'openid'
}
const passReqToCallback = false; // optional, defaults to false, when true req is passed as a first
                                 // argument to verify fn

const usePKCE = true; // optional, defaults to false, when true the code_challenge_method will be
                      // resolved from the issuer configuration, instead of true you may provide
                      // any of the supported values directly, i.e. "S256" (recommended) or "plain"

passport.use('oidc', new Strategy({ client, [params], [passReqToCallback], [usePKCE] }, (tokenset, userinfo, done) => {
  console.log('tokenset', tokenset);
  console.log('access_token', tokenset.access_token);
  console.log('id_token', tokenset.id_token);
  console.log('claims', tokenset.claims);
  console.log('userinfo', userinfo);

  User.findOne({ id: tokenset.claims.sub }, function (err, user) {
    if (err) return done(err);
    return done(null, user);
  });
}));

// start authentication request
// options [optional], extra authentication parameters
app.get('/auth', passport.authenticate('oidc', [options]));

// authentication callback
app.get('/auth/cb', passport.authenticate('oidc', { successRedirect: '/', failureRedirect: '/login' }));

Configuration

Allow for system clock skew

It is possible the RP or OP environment has a system clock skew, to set a clock tolerance (in seconds)

client.CLOCK_TOLERANCE = 5; // to allow a 5 second skew

Changing HTTP request defaults

Setting defaultHttpOptions on Issuer always merges your passed options with the default. openid-client uses got for http requests with the following default request options

const DEFAULT_HTTP_OPTIONS = {
  followRedirect: false,
  headers: { 'User-Agent': `${pkg.name}/${pkg.version} (${pkg.homepage})` },
  retries: 0,
  timeout: 1500,
};

You can add your own headers, change the user-agent used or change the timeout setting

Issuer.defaultHttpOptions = { timeout: 2500, headers: { 'X-Your-Header': '<whatever>' } };

Confirm your httpOptions by

console.log('httpOptions %j', Issuer.defaultHttpOptions);