JWT Services

CBSecurity also provides you with a JWT (Json Web Tokens) authentication and authorization system.

JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. This information can be verified and trusted because it is digitally signed. JWTs can be signed using a secret (with the HMAC algorithm) or a public/private key pair using RSA or ECDSA.

Signed tokens can verify the integrity of the claims contained within it, while encrypted tokens hide those claims from other parties. When tokens are signed using public/private key pairs, the signature also certifies that only the party holding the private key is the one that signed it.

You can find much more information about JWT at jwt.io.

When should you use JSON Web Tokens?

JSON Web Tokens have become the standard for authenticating and authorizing API requests. They can be used on their own or with an oauth/single sign-on server as well.

  • Authorization: This is the most common scenario for using JWT. Once the user is logged in, each subsequent request will include the JWT, allowing the user to access routes, services, and resources that are permitted with that token.

  • Information Exchange: JSON Web Tokens are a good way of securely transmitting information between parties. Because JWTs can be signed—for example, using public/private key pairs—you can be sure the senders are who they say they are. Additionally, as the signature is calculated using the header and the payload, you can also verify that the content hasn't been tampered with.

The ColdBox Security module will assist you with all the generation, decoding, encoding and security aspects of JWT. All you need to do is, configure it, create a few standard files and off you go.

Tokens

The tokens created by the JWT services will have the mandatory headers, but also will have a standardizes payload structure. This payload structure can also be customized as you see fit.

A JSON Web Token encodes a series of claims in a JSON object. Some of these claims have specific meaning, while others are left to be interpreted by the users. You can consider claims to be the keys of the payload structure and it can contain, well, pretty much anything you like.

Base Claims

Here are the base claims that the ColdBox Security JWT token creates for you automatically:

  • Issuer (iss) - The issuer of the token (defaults to the application's base URL)

  • Issued At (iat) - When the token was issued (unix timestamp)

  • Subject (sub) - This holds the identifier for the token (defaults to user id)

  • Expiration time (exp) - The token expiry date (unix timestamp)

  • Unique ID (jti) - A unique identifier for the token (md5 of the sub and iat claims)

  • Scopes (scopes) - An array of scopes attached to the token

mytoken.json
{
"iat": 1569340662,
"scopes": [],
"iss": "http://127.0.0.1:56596/",
"sub": 123,
"exp": 1569344262,
"jti": "12954F907C0535ABE97F761829C6BD11"
}

You can add much more to this payload via the JWT service methods or via the User that models the token.

Our JwtService

The service can be found here cbsecurity.models.JWTService and can be retrieved by either injecting the service (JwtService@cbsecurity) or using our helper method (jwtAuth()).

// Injection
property name="jwtService" inject="JwtService@cbsecurity";
// Helper Method in any handler/layout/interceptors/views
jwtAuth()

In order to begin exploring the JWT capabilities, let's explore how to configure it first.

Configuration

Our JWT services have several configuration settings, let's explore them:

cbsecurity : {
// The WireBox ID of the authentication service to use in cbSecurity which must adhere to the cbsecurity.interfaces.IAuthService interface.
authenticationService : "authenticationService@cbauth",
// WireBox ID of the user service to use
userService : "",
// The name of the variable to use to store an authenticated user in prc scope if using a validator that supports it.
prcUserVariable : "oCurrentUser",
// JWT Settings
jwt : {
// The jwt secret encoding key, defaults to getSystemEnv( "JWT_SECRET", "" )
secretKey : getSystemSetting( "JWT_SECRET", "" ),
// by default it uses the authorization bearer header, but you can also pass a custom one as well.
customAuthHeader : "x-auth-token",
// The expiration in minutes for the jwt tokens
expiration : 60,
// encryption algorithm to use, valid algorithms are: HS256, HS384, and HS512
algorithm : "HS512",
// Which claims neds to be present on the jwt token or `TokenInvalidException` upon verification and decoding
requiredClaims : [] ,
// The token storage settings
tokenStorage : {
// enable or not, default is true
"enabled" : true
// A cache key prefix to use when storing the tokens
"keyPrefix" : "cbjwt_",
// The driver to use: db, cachebox or a WireBox ID
"driver" : "cachebox",
// Driver specific properties
"properties" : {
cacheName : "default"
}
}
}
}

Authentication Service

The WireBox Id of the service to provide our authentication. cbauth is our default provider, but you can use any authentication service that adheres to our interface.

User Service

The WireBox Id of the service to provide our user retrieval and validation functions. You can use any service that adheres to our interface.

prcUserVariable

The default variable name in the prc scope that will be used to store an authenticated user object if the JWT request is valid. The default is prc.oCurrentUser

secretKey

The secret key is mandatory and its the way to sign the JWT tokens. By default it will try to load an environment variable called JWT_SECRET if the setting is ommitted.

customAuthHeader

By default, our jwt services will look into the authorization header for a bearer token. However, it can also look in a custom header by this name, which defaults to x-auth-token. Finally, if not found, it will also look into the rc scope for a rc[ 'x-auth-token' ] as well.

Expiration

The default expiration in minutes for the JWT tokens. Defaults to 60 minutes

Algorithm

The encryption algorithm to use for the tokens. The default is HS512, but the available ones for now are:

  • HS256

  • HS384

  • HS512

RequiredClaims

This is an array of claim names that each token MUST have in order to be authenticated. If a token comes in but does not have these claims in the payload structure, it will be deemed invalid.

Token Storage

By default, our JWT services will store tokens in CacheBox for you in order to be able to invalidate them and in the future provide refresh tokens. We ship with two providers for token storage: db and cachebox.

Enabled

By default the token storage is enabled.

KeyPrefix

The key prefix to use when storing the keys in the permanent storage. Defaults to cbjwt_

Driver

The driver to use. Can be either db or cachebox or your own WireBox Id for using a custom storage.

Properties

A struct of properties to configure each storage with.

JWT Subject Interface

The next step is to make sure that our JWT services can handle the construction of the JWT tokens as per YOUR requirements. So your User object must implement our JWTSubject interface with the following functions:

cbsecurity.interfaces.jwt.IJwtSubject.cfc
interface{
/**
* A struct of custom claims to add to the JWT token
*/
struct function getJwtCustomClaims();
/**
* This function returns an array of all the scopes that should be attached to the JWT token that will be used for authorization.
*/
array function getJwtScopes();
}

Basically, it's two functions:

  • getJwtCustomClaims() - This is a struct of custom claims to incorporate into the token payload at construction time. This can be ANYTHING you like

  • getJwtScopes() - We will also call this at construction time in order to incorporate the right permission scopes into the token according to your user. This must be an array of scopes/permissions.

Since also the authentication services will be used with JWT, your user object might end up looking like this:

models/User.cfc
component accessors="true" {
property name="auth" inject="authenticationService@cbauth";
property name="id";
property name="firstName";
property name="lastName";
property name="username";
property name="password";
function init(){
variables.id = "";
variables.firstName = "";
variables.lastName = "";
variables.username = "";
variables.password = "";
variables.permissions = [ "write", "read" ];
return this;
}
boolean function isLoaded(){
return ( !isNull( variables.id ) && len( variables.id ) );
}
/**
* A struct of custom claims to add to the JWT token
*/
struct function getJWTCustomClaims(){
return { "role" : "admin" };
}
/**
* This function returns an array of all the scopes that should be attached to the JWT token that will be used for authorization.
*/
array function getJWTScopes(){
return variables.permissions;
}
/**
* Verify if the user has one or more of the passed in permissions
*
* @permission One or a list of permissions to check for access
*
*/
boolean function hasPermission( required permission ){
if ( isSimpleValue( arguments.permission ) ) {
arguments.permission = listToArray( arguments.permission );
}
return arguments.permission
.filter( function(item){
return ( variables.permissions.findNoCase( item ) );
} )
.len();
}
/**
* Shortcut to verify it the user is logged in or not.
*/
boolean function isLoggedIn(){
return auth.isLoggedIn();
}
}

Authentication and User Services

Please note that the JWT validators must talk to the authentication and user services. Please refer to the Authentication Services page to configure and create them.

JWT Methods

Ok, now we can focus on all the wonderful methods the JWT service offers:

  • attempt( username, password, [ customClaims:struct ] ):token - Attempt to authenticate a user with the authentication service and if successful, return the token using the identifier and custom claims. Exception if invalid authentication.

  • fromUser( user, [ customClaims:struct ] ):token - Generate a token according to the passed user object and custom claims.

  • encode( struct payload ):token - Generate a raw jwt token from a native payload struct.

  • verify( required token ):boolean - Verify a token string or throws exception

  • decode( required token ):struct - Decode and retrieve the passed in token to CFML struct

  • parseToken():struct - Get the decoded token using the headers strategy and store it in the prc.jwt_token and the decoded data as prc.jwt_payload if it verifies correctly. Throws: TokenExpiredException if the token is expired, TokenInvalidException if the token doesn't verify decoding, TokenNotFoundException if not found

  • getToken():string - Get the stored token from prc.jwt_token, if it doesn't exist, it tries to parse it via parseToken(), if not token is set this will be an empty string.

  • getPayload():struct - Get the stored token from prc.jwt_payload, if it doesn't exist, it tries to parse it via parseToken(), if not token is set this will be an empty struct.

  • setToken( token ):JWTService - Store the token in prc.jwt_token, and store the decoded version in prc.jwt_payload

  • getuser() - Get the authenticated user

  • authenticate( [token] ):User - Calls the auth service using the parsed token or optional passed token, to get the user by subject claim else throw an exception

  • invalidate( token ) - Invalidates the incoming token by removing it from the permanent storage, no key in storage, it's invalid.

  • logout() - Logout a user and invalidate their token

Putting it Together

That's it, we are ready to put it all together. Now cbsecurity knows about your authentication/user services, can talk to your user to create tokens and can guard the incoming requests via the JWT Validator. Here is a sample controller for login, logout and user registration:

Let's configure some routes first:

post( "/api/login" , "api.auth.login" );
post( "/api/logout" , "api.auth.logout" );
post( "/api/register" , "api.auth.register" );

Then build out the Auth controller

component{
function login( event, rc, prc ){
param rc.username = "";
param rc.password = "";
try {
var token = jwtAuth().attempt( rc.username, rc.password );
return {
"error" : true,
"data" : token,
"message" : "Bearer token created and it expires in #jwtAuth().getSettings().jwt.expiration# minutes"
};
} catch ( "InvalidCredentials" e ) {
event.setHTTPHeader( statusCode = 401, statusText = "Not Authorized" );
return { "error" : true, "data" : "", "message" : "Invalid Credentials" };
}
}
function register( event, rc, prc ){
param rc.firstName = "";
param rc.lastName = "";
param rc.username = "";
param rc.password = "";
prc.oUser = populateModel( "User" );
userService.create( prc.oUser );
var token = jwtAuth().fromuser( prc.oUser );
return {
"error" : true,
"data" : token,
"message" : "User registered correctly and Bearer token created and it expires in #jwtAuth().getSettings().jwt.expiration# minutes"
};
}
function logout( event, rc, prc ){
jwtAuth().logout();
return { "error" : false, "data" : "", "message" : "Successfully logged out" };
}
}

Make sure you add validation!

That's it, we now can login a user, give them a token, register a new user and give them their token, and also log them out. The next step is for you to build your rules and/or security annotations and make sure the JWT validator is configured for your global app or module.