ginkeycloak

README

Gin-Keycloak

Gin-Keycloak is specially made for Gin Framework users who also want to use Keycoak. This Project was inspired by zalando's gin-oauth

Project Context and Features

When it comes to choosing a Go framework, there's a lot of confusion about what to use. The scene is very fragmented, and detailed comparisons of different frameworks are still somewhat rare. Meantime, how to handle dependencies and structure projects are big topics in the Go community. We've liked using Gin for its speed, accessibility, and usefulness in developing microservice architectures. In creating Gin-OAuth2, we wanted to take fuller advantage of Gin's capabilities and help other devs do likewise.

Gin-Keycloak is expressive, flexible, and very easy to use. It allows you to:

• do OAuth2 authorization based on the JWT Token
• create router groups to place Keycloak authorization on top, using HTTP verbs and passing them
• more easily decouple services by promoting a "say what to do, not how to do it" approach
• configure your REST API directly in the code (see the "Usage" example below)
• write your own authorization functions

Requirements

• Gin
• An Keycloak Token provider

Gin-Keycloak uses the following Go packages as dependencies:

• Gin
• glog
• gin-glog

Installation

Assuming you've installed Go and Gin, run this:

go get github.com/tbaehler/gin-keycloak

Usage

Uid-Based Access

First, define your access triples to identify who has access to a given resource. This snippet shows how to grant resource access to two hypothetical employees:

//from ginkeycloak package
// AccessTuple is the type defined for use in AccessTuples.
  
        type AccessTuple struct {
       	    Service string
       	    Role    string
       	    Uid     string
        }
    
var GRANTED_USERS  = []ginkeycloak.AccessTuple{{Uid: "domain\user1"}}

Next, define which Gin middlewares you use. The third line in this snippet is a basic audit log:

router := gin.New()
router.Use(ginglog.Logger(3 * time.Second))
router.Use(ginkeycloak.RequestLogger([]string{"uid"}, "data"))
router.Use(gin.Recovery())

Finally, define which type of access you grant to the defined users. We'll use a router group, so that we can add a bunch of router paths and HTTP verbs:

privateUser := router.Group("/api/privateUser")
privateUser.Use(ginkeycloak.Auth(ginkeycloak.UidCheck(USERS), keycloakConfig))
privateUser.GET("/", func(c *gin.Context) {
	....
})

Testing

To test, you can use curl:

    curl -H "Authorization: Bearer $TOKEN" http://localhost:8081/api/privateUser/
    {"message":"Hello from private for users to Sandor Szücs"}

Role-Based Access

As with Uid-based access, define your access triples to identify who has access to a given resource. With this snippet, you can grant resource access to an entire team instead of individuals:

var GRANTED_ROLE  = []ginkeycloak.AccessTuple{
    {Service: "keycloak-service", Role: "keycloak-role"},
}

Now define which Gin middlewares you use:

router := gin.New()
router.Use(ginglog.Logger(3 * time.Second))
router.Use(ginkeycloak.RequestLogger([]string{"uid"}, "data"))
router.Use(gin.Recovery())

A Keycloakconfig

var sbbEndpoint = ginkeycloak.KeycloakConfig{
    Url:  "https://keycloack.domain.ch/",
    Realm: "Your Realm",
}

Lastly, define which type of access you grant to the defined team. We'll use a router group again:

privateGroup := router.Group("/api/privateGroup")
privateGroup.Use(ginkeycloak.Auth(ginkeycloak.GroupCheck(GRANTED_ROLE), keycloakconfig))
privateGroup.GET("/", func(c *gin.Context) {
	uid, okUid := c.Get("uid")
	....
})

Once again, you can use curl to test:

    curl -H "Authorization: Bearer $TOKEN" http://localhost:8081/api/privateGroup/
    {"message":"Hello from private to sszuecs member of teapot"}

Contributors

Thanks to:

• Zalando Team for their initial work

License

See MIT-License LICENSE file.

Documentation

Overview

Package gin-keycloak implements an Keycloak based authorization middleware for the Gin https://github.com/gin-gonic/gin

Package zalando contains Zalando specific definitions for authorization.

Index

• Variables
• func Auth(accessCheckFunction AccessCheckFunction, endpoints KeycloakConfig) gin.HandlerFunc
• func AuthChain(config KeycloakConfig, accessCheckFunctions ...AccessCheckFunction) gin.HandlerFunc
• func GroupCheck(at []AccessTuple) func(tc *TokenContainer, ctx *gin.Context) bool
• func RequestLogger(keys []string, contentKey string) gin.HandlerFunc
• func UidCheck(at []AccessTuple) func(tc *TokenContainer, ctx *gin.Context) bool
• type AccessCheckFunction
• type AccessTuple
• type KeyCloakToken
• type KeycloakConfig
• type ServiceRole
• type TokenContainer
  • func GetTokenContainer(token *oauth2.Token, config KeycloakConfig) (*TokenContainer, error)
  • func (t *TokenContainer) Valid() bool

Variables

var Transport = http.Transport{}

var VarianceTimer time.Duration = 30000 * time.Millisecond

VarianceTimer controls the max runtime of Auth() and AuthChain() middleware

Functions

func Auth

func Auth(accessCheckFunction AccessCheckFunction, endpoints KeycloakConfig) gin.HandlerFunc

func AuthChain

func AuthChain(config KeycloakConfig, accessCheckFunctions ...AccessCheckFunction) gin.HandlerFunc

func GroupCheck

func GroupCheck(at []AccessTuple) func(tc *TokenContainer, ctx *gin.Context) bool

func RequestLogger

func RequestLogger(keys []string, contentKey string) gin.HandlerFunc

func UidCheck

func UidCheck(at []AccessTuple) func(tc *TokenContainer, ctx *gin.Context) bool

Types

type AccessCheckFunction

type AccessCheckFunction func(tc *TokenContainer, ctx *gin.Context) bool

AccessCheckFunction is a function that checks if a given token grants access.

type AccessTuple

type AccessTuple struct {
	Service string
	Role    string
	Uid     string
}

AccessTuple is the type defined for use in AccessTuples.

type KeyCloakToken

type KeyCloakToken struct {
	Jti               string                 `json:"jti"`
	Exp               int64                  `json:"exp"`
	Nbf               int64                  `json:"nbf"`
	Iat               int64                  `json:"iat"`
	Iss               string                 `json:"iss"`
	Aud               []string               `json:"aud"`
	Sub               string                 `json:"sub"`
	Typ               string                 `json:"typ"`
	Azp               string                 `json:"azp"`
	Nonce             string                 `json:"nonce"`
	AuthTime          int64                  `json:"auth_time"`
	SessionState      string                 `json:"session_state"`
	Acr               string                 `json:"acr"`
	ClientSession     string                 `json:"client_session"`
	AllowedOrigins    []string               `json:"allowed-origins"`
	ResourceAccess    map[string]ServiceRole `json:"resource_access"`
	Name              string                 `json:"name"`
	PreferredUsername string                 `json:"preferred_username"`
	GivenName         string                 `json:"given_name"`
	FamilyName        string                 `json:"family_name"`
	Email             string                 `json:"email"`
}

type KeycloakConfig

type KeycloakConfig struct {
	Url   string
	Realm string
}

type ServiceRole

type ServiceRole struct {
	Roles []string `json:"roles"`
}

type TokenContainer

type TokenContainer struct {
	Token         *oauth2.Token
	KeyCloakToken *KeyCloakToken
}

TokenContainer stores all relevant token information

func GetTokenContainer

func GetTokenContainer(token *oauth2.Token, config KeycloakConfig) (*TokenContainer, error)

func (*TokenContainer) Valid

func (t *TokenContainer) Valid() bool