NestJS OIDC

A configurable OIDC library for NestJS and GraphQL or REST.

- Install
- Basic Setup & Usage
- Guards
- REST
- GraphQL
- Current User
- REST
- GraphQL
- Roles
- Role Evaluators
- JWT Mapping
- Advanced
- Authenticating GraphQL Subscriptions
- Optional Authentication
- Release

Install

Install nest-oidc:

``sh
npm i @5stones/nest-oidc
`

Install it's peer dependencies:

`sh
npm i @nestjs/jwt @nestjs/passport passport passport-jwt
`

:warning: Note: If you're using this package for GraphQL you'll need the
corresponding GQL libraries installed.
Please follow the NestJS documentation first.

Basic Setup & Usage

You'll need to import and configure the AuthModule in your application. This
package contains a JWT authentication strategy which will validate a JWT against
the issuer's public key. You must pass configure a value for the oidcAuthority.

`ts
import { Module } from '@nestjs/common';
import { AuthModule } from '@5stones/nest-oidc';

@Module({
imports: [
...
AuthModule.forRoot({
oidcAuthority: 'http://iam.app.com/auth/realms/app',
}),
],
})
export class AppModule {}
`

This will add the JWT validation strategy, and will verify any incoming JWT's
against the OIDC authorities public keys.

Finally, you should decorate your endpoints with the provided guards.

Guards

This package exports two basic guards:

- JwtAuthGuard - for use in REST contexts.
- JwtAuthGuardGraphQL - for use in GQL contexts.

#### REST Guard

Applying the guard will require a valid JWT to be passed in order to access any
of the controller endpoints:

`ts
import { Controller, Get, UseGuards } from '@nestjs/common';
import { Roles, JwtAuthGuard } from '@5stones/nest-oidc';

@UseGuards(JwtAuthGuard)
@Controller('cats')
export class CatsController {
@Get()
findAll(): string {
return 'This action returns all cats';
}
}
`

You can also use it on specific endpoints:

`ts
import { Controller, Get, Post, UseGuards } from '@nestjs/common';
import { Roles, JwtAuthGuard } from '@5stones/nest-oidc';

@Controller('cats')
export class CatsController {
@UseGuards(JwtAuthGuard)
@Post()
create(): string {
return 'This action adds a new cat';
}

@Get()
findAll(): string {
return 'This action returns all cats';
}
}
`

#### GraphQL Guard

Applying the guard will require a valid JWT to be passed in order to access any
of the controller endpoints:

`ts
import { UseGuards } from '@nestjs/common';
import { Resolver } from '@nestjs/graphql';
import { JwtAuthGuardGraphQL } from '@5stones/nest-oidc';

@UseGuards(JwtAuthGuardGraphQL)
@Resolver(() => Cat)
export class CatResolver {
...
}
`

You can also use it on specific endpoints:

`ts
import { UseGuards } from '@nestjs/common';
import { Resolver, Query, Mutation } from '@nestjs/graphql';
import { JwtAuthGuardGraphQL } from '@5stones/nest-oidc';

@Resolver(() => Cat)
export class CatResolver {

@Query(() => [Cat], { name: 'allCats' })
async findAll() {
...
}

@UseGuards(JwtAuthGuardGraphQL)
@Mutation(() => Cat, { name: 'createCat' })
async create() {
...
}
}
`

Current User

This package exports two basic user decorators:

- CurrentUser - for use in REST contexts.
- CurrentUserGraphQL - for use in GQL contexts.

#### REST User

`ts
import { Controller, Get, UseGuards } from '@nestjs/common';
import { Roles, JwtAuthGuard, CurrentUser } from '@5stones/nest-oidc';

@UseGuards(JwtAuthGuard)
@Controller('cats')
export class CatsController {
@Get()
findAll(@CurrentUser() user: any): string {
return 'This action returns all cats';
}
}
`


#### GraphQL User


`ts
import { UseGuards } from '@nestjs/common';
import { Resolver, Query } from '@nestjs/graphql';
import { JwtAuthGuardGraphQL, CurrentUserGraphQL } from '@5stones/nest-oidc';

@UseGuards(JwtAuthGuardGraphQL)
@Resolver(() => Cat)
export class CatResolver {

@Query(() => [Cat], { name: 'allCats' })
async findAll(@CurrentUserGraphQL() user: any) {
...
}
}
`

Roles

If you want to permission different endpoints based on properties of the JWT you
can do so using the Roles decorator in conjunction with the Auth Guards (both
REST & GQL). The Roles decorator will accept a list of strings and will
check if the user object accessing that endpoint has any of those strings in the
user.roles property. It expects the user.roles property to be a flat array
of strings.

#### Example

`ts
import { UseGuards } from '@nestjs/common';
import { Resolver, Query, Mutation, Args, ID } from '@nestjs/graphql';
import { JwtAuthGuardGraphQL, Roles } from '@5stones/nest-oidc';

@UseGuards(JwtAuthGuardGraphQL)
@Resolver(() => Cat)
export class CatResolver {

@Query(() => [Cat], { name: 'allCats' })
async findAll(): Promise {
...
}

@Roles()
@Query(() => Cat, { name: 'Cat' })
async findOne(@Args('id', { type: () => ID }) id: number): Promise {
...
}

@Roles('ADMIN', 'SUPER_ADMIN')
@Mutation(() => Cat, { name: 'createCat' })
async create(): Promise {
...
}
}
`

In this scenario, the mutation can only be executed by an ADMIN or SUPER_ADMIN
but the query can be executed by any user with a valid JWT.

:warning: Note: if you do not pass _any_ roles parameters to the Roles
decorator (i.e. @Roles()) it is the same as not adding the decorator at all.
That is to say, any scenario above the findAll and the findOne queries
behave identically.

Role Evaluators

If your JWT doesn't natively have a .roles property of strings on it, you can
use evaluators to map properties of the JWT to a role. You can do so by
configuring roleEvaluators. roleEvaluators are an array of
RoleEvaluator objects which consist of an expression, and the access role
that that particular expression grants upon evaluating to true.

An expression can be any valid jexl
expression.

#### Example

Suppose you have a JWT with the following structure:

`ts
{
roles: [
{ name: "SUPER_USER", id: 1 },
...
{ name: "PREMIUM", id: 2 },
],
}
`

You could then configure an evaluator like the following, which would map a
user that has a role of with the name of SUPER_USER to the ADMIN
role in your application.

`ts
import { Module } from '@nestjs/common';
import { AuthModule } from '@5stones/nest-oidc';

@Module({
imports: [
...
AuthModule.forRoot({
oidcAuthority: 'http://iam.app.com/auth/realms/app',
roleEvaluators: [
{
expression: 'jwt.roles[.name == "SUPER_USER"]|length > 0',
role: 'ADMIN',
},
],
}),
],
})
export class AppModule {}
`

The user object within your application will now have the following:

`ts
{
...
roles: [
"ADMIN",
],
}
`

Then you would simply decorate your endpoint with the @Roles('ADMIN')
annotation in order to lock it down to users of that role.

JWT Mapper

By default, the JWT payload is passed as the user into the application. However,
if you need to map the JWT payload to different structure you can pass the
jwtMapper option:

`ts
import { Module } from '@nestjs/common';
import { AuthModule } from '@5stones/nest-oidc';

@Module({
imports: [
...
AuthModule.forRoot({
oidcAuthority: 'http://iam.app.com/auth/realms/app',
jwtMapper: async (payload: any) => ({
id: payload.sub,
email: payload.email,
...
}),
}),
],
})
export class AppModule {}
`

Advanced

#### Authenticating GraphQL Subscriptions

The websocket spec doesn't support headers, so if you want to authenticate a
GraphQL Subscription via the standard Guard & Role decorators you can do so, but
you'll need to modify your GraphQLModule configuration. The below example will
walk you through how to do it with the graphql-ws library.

The first step is to make sure that you're passing the Auth token as a parameter
through your websocket request. Read more in the graphql-ws docs

Next you'll need to modify the GraphQLModule's onConnect and context
functions to map the token and the request. You can read the NestJS documentation
on generally how to do this, but that documentation only deals with the validation
of the token directly in the onConnect function. However to allow it to be
done by the Guards you'll need to map the token into a header on a request object
and then ensure that you're always returning a request to be processed by the
JwtStrategy. See the example below:


`ts
// app.module.ts
...
import type { Context } from 'graphql-ws';

...
@Module({
imports: [
GraphQLModule.forRoot({
...
subscriptions: {
'graphql-ws': {
onConnect: (context: Context) => {
const { connectionParams, extra } = context;
const authToken = connectionParams?.Authorization;

if (authToken) {
// Add the auth token to the request object provided by graphql-ws
// NOTE: headers are lowercased in express. Using Authorization
// will result in a failure to authenticate.
extra.request.headers.authorization = authToken;
}
},
}
},
context: (context) => {
if (context?.req === undefined) {
// The jwt strategy requires a request with headers to perform jwt
// validation. If no request exists in the context object then we're
// dealing with a websocket connection. In that case pass along the
// request object provided by the graphql-ws context for validation.
context.req = context.extra.request;
}

// return the context object.
return context;
},
}),
...
],
})
export class AppModule implements NestModule {
...
}
`

Once this has been configured you'll be able to apply the JwtAuthGuardGraphQL
and Roles decorators as you would on any other resolver, query, or mutation.

#### Optional Authentication

You can use the IsAuthenticationOptional decorator on an endpoint or resolver
in conjunction with an auth guard. If this is done so, then JWTs will populate
user object as expected. If an invalid JWT is passed or no JWT is passed at
all, then no user will be populated on the request.

Release

The standard release command for this project is:
`
npm version [ | major | minor | patch | premajor | preminor | prepatch | prerelease | from-git]
`

This command will:

1. Generate/update the Changelog
1. Bump the package version
1. Tag & pushing the commit


e.g.

`
npm version 1.2.17
npm version patch // 1.2.17 -> 1.2.18
``