Every app needs authentication and authorization. Logto is an Auth0 alternative designed for modern apps and SaaS products.
In this article, we will go through the steps to quickly build the OIDC sign-in experience (user authentication) with Go and Logto.
Prerequisites
- A running Logto instance. Check out the introduction page to get started.
- Basic knowledge of Go.
- A usable OIDC account.
Create an application in Logto
In you browser, open a new tab and enter the link of Logto Admin Console.
Once the page is loaded, in the "Get Started" section click the View all
link to open the application framework list page.
Choose your application type
In the opening modal, scroll to the "Traditional web" section or filter all the available " Traditional web" frameworks using the quick filter checkboxes on the left.
Click the "undefined" framework card to start creating your application.
Enter application name
Enter the application name, e.g., "Bookstore," and click "Create application."
🎉 Ta-da! You just created your first application in Logto. You'll see a congrats page which includes a detailed integration guide. Follow the guide to see what the experience will be in your application.
Integrate Logto SDK
- The following demonstration is built upon the Gin Web Framework. You may also integrate Logto into other frameworks by taking the same steps.
- The Go sample project is available on our Go SDK repo.
Installation
Execute in the project root directory:
go get github.com/logto-io/go
Add the github.com/logto-io/go/client
package to your application code:
// main.go
package main
import (
"github.com/gin-gonic/gin"
// Add dependency
"github.com/logto-io/go/client"
)
func main() {
router := gin.Default()
router.GET("/", func(c *gin.Context) {
c.String(200, "Hello Logto!")
})
router.Run(":3000")
}
Create a session storage
In traditional web applications, the user authentication information will be stored in the user session.
Logto SDK provides a Storage
interface, you can implement a Storage
adapter based on your web framework so that the Logto SDK can store user authentication information in the session.
We do NOT recommend using cookie-based sessions, as user authentication information stored by Logto may exceed the cookie size limit. In this example, we use memory-based sessions. You can use Redis, MongoDB, and other technologies in production to store sessions as needed.
The Storage
type in the Logto SDK is as follows:
package client
type Storage interface {
GetItem(key string) string
SetItem(key, value string)
}
We use github.com/gin-contrib/sessions middleware as an example to demonstrate this process.
Apply the middleware to the application, so that we can get the user session by the user request context in the route handler:
package main
import (
"github.com/gin-contrib/sessions"
"github.com/gin-contrib/sessions/memstore"
"github.com/gin-gonic/gin"
"github.com/logto-io/go/client"
)
func main() {
router := gin.Default()
// We use memory-based session in this example
store := memstore.NewStore([]byte("your session secret"))
router.Use(sessions.Sessions("logto-session", store))
router.GET("/", func(ctx *gin.Context) {
// Get user session
session := sessions.Default(ctx)
// ...
ctx.String(200, "Hello Logto!")
})
router.Run(":3000")
}
Create a session_storage.go
file, define a SessionStorage
and implement the Logto SDK's Storage
interfaces:
package main
import (
"github.com/gin-contrib/sessions"
)
type SessionStorage struct {
session sessions.Session
}
func (storage *SessionStorage) GetItem(key string) string {
value := storage.session.Get(key)
if value == nil {
return ""
}
return value.(string)
}
func (storage *SessionStorage) SetItem(key, value string) {
storage.session.Set(key, value)
storage.session.Save()
}
Now, in the route handler, you can create a session storage for Logto:
session := sessions.Default(ctx)
sessionStorage := &SessionStorage{session: session}
Init LogtoClient
First, create a Logto config:
func main() {
// ...
logtoConfig := &client.LogtoConfig{
Endpoint: "<your-logto-endpoint>", // E.g. http://localhost:3001
AppId: "<your-application-id>",
AppSecret: "<your-application-secret>",
}
// ...
}
You can find and copy "App Secret" from application details page in Admin Console:
Then, you can create a LogtoClient
for each user request with the Logto config above:
func main() {
// ...
router.GET("/", func(ctx *gin.Context) {
// Create LogtoClient
session := sessions.Default(ctx)
logtoClient := client.NewLogtoClient(
logtoConfig,
&SessionStorage{session: session},
)
// Use Logto to control the content of the home page
authState := "You are not logged in to this website. :("
if logtoClient.IsAuthenticated() {
authState = "You are logged in to this website! :)"
}
homePage := `<h1>Hello Logto</h1>` +
"<div>" + authState + "</div>"
ctx.Data(http.StatusOK, "text/html; charset=utf-8", []byte(homePage))
})
// ...
}
Implement sign-in route
After the redirect URI is configured, we add a sign-in
route to handle the sign-in request and also add an sign-in link on the home page:
func main() {
// ...
// Add a link to perform a sign-in request on the home page
router.GET("/", func(ctx *gin.Context) {
// ...
homePage := `<h1>Hello Logto</h1>` +
"<div>" + authState + "</div>" +
// Add link
`<div><a href="/sign-in">Sign In</a></div>`
ctx.Data(http.StatusOK, "text/html; charset=utf-8", []byte(homePage))
})
// Add a route for handling sign-in requests
router.GET("/sign-in", func(ctx *gin.Context) {
session := sessions.Default(ctx)
logtoClient := client.NewLogtoClient(
logtoConfig,
&SessionStorage{session: session},
)
// The sign-in request is handled by Logto.
// The user will be redirected to the Redirect URI on signed in.
signInUri, err := logtoClient.SignIn("http://localhost:3000/callback")
if err != nil {
ctx.String(http.StatusInternalServerError, err.Error())
return
}
// Redirect the user to the Logto sign-in page.
ctx.Redirect(http.StatusTemporaryRedirect, signInUri)
})
// ...
}
Now, when your user visit http://localhost:3000/sign-in
, the user will be redirected to the Logto sign-in page.
Implement the callback route
When the user signs in successfully on the Logto sign-in page, Logto will redirect the user to the Redirect URI.
Since the redirect URI is http://localhost:3000/callback
, we add the /callback
route to handle the callback after signing in.
func main() {
// ...
// Add a route for handling sign-in callback requests
router.GET("/callback", func(ctx *gin.Context) {
session := sessions.Default(ctx)
logtoClient := client.NewLogtoClient(
logtoConfig,
&SessionStorage{session: session},
)
// The sign-in callback request is handled by Logto
err := logtoClient.HandleSignInCallback(ctx.Request)
if err != nil {
ctx.String(http.StatusInternalServerError, err.Error())
return
}
// Jump to the page specified by the developer.
// This example takes the user back to the home page.
ctx.Redirect(http.StatusTemporaryRedirect, "/")
})
// ...
}
Implement sign-out route
Similar to the sign-in flow, when the user signs out, Logto will redirect the user to the post sign-out redirect URI.
Now, let's add the sign-out
route to handle the sign-out request and also add a sign-out link on the home page:
func main() {
// ...
// Add a link to perform a sign-out request on the home page
router.GET("/", func(ctx *gin.Context) {
// ...
homePage := `<h1>Hello Logto</h1>` +
"<div>" + authState + "</div>" +
`<div><a href="/sign-in">Sign In</a></div>` +
// Add link
`<div><a href="/sign-out">Sign Out</a></div>`
ctx.Data(http.StatusOK, "text/html; charset=utf-8", []byte(homePage))
})
// Add a route for handling signing out requests
router.GET("/sign-out", func(ctx *gin.Context) {
session := sessions.Default(ctx)
logtoClient := client.NewLogtoClient(
logtoConfig,
&SessionStorage{session: session},
)
// The sign-out request is handled by Logto.
// The user will be redirected to the Post Sign-out Redirect URI on signed out.
signOutUri, signOutErr := logtoClient.SignOut("http://localhost:3000")
if signOutErr != nil {
ctx.String(http.StatusOK, signOutErr.Error())
return
}
ctx.Redirect(http.StatusTemporaryRedirect, signOutUri)
})
// ...
}
After the user makes a signing-out request, Logto will clear all user authentication information in the session.
Open your Go app to test if the integration works. When you click the "Sign In" button, the page should be redirected to a Logto sign-in page, and you should be able to create a new account by entering username and password and complete the sign-in process.
Add OIDC connector
To add a social connector, go to the "Connector" tab in the Admin Console, then click on "Social connectors". From there, click "Add social connector".
In the openning modal, select "OIDC" and click "Next".
On the next page, you will see a two-column layout with the README content on the left and configuration on the right.
Feel free to follow the README file in place or read the following section to complete the configuration process. If you follow the in-place guide, you can skip the next section.
Set up Standard OIDC app
Create your OIDC app
When you open this page, we believe you already know which social identity provider you want to connect to. The first thing to do is to confirm that the identity provider supports the OIDC protocol, which is a prerequisite for configuring a valid connector. Then, follow the identity provider's instructions to register and create the relevant app for OIDC authorization.
Configure your connector
We ONLY support "Authorization Code" grant type for security consideration and it can perfectly fit Logto's scenario.
clientId
and clientSecret
can be found at your OIDC apps details page.
clientId: The client ID is a unique identifier that identifies the client application during registration with the authorization server. This ID is used by the authorization server to verify the identity of the client application and to associate any authorized access tokens with that specific client application.
clientSecret: The client secret is a confidential key that is issued to the client application by the authorization server during registration. The client application uses this secret key to authenticate itself with the authorization server when requesting access tokens. The client secret is considered confidential information and should be kept secure at all times.
scope: The scope parameter is used to specify the set of resources and permissions that the client application is requesting access to. The scope parameter is typically defined as a space-separated list of values that represent specific permissions. For example, a scope value of "read write" might indicate that the client application is requesting read and write access to a user's data.
You are expected to find authorizationEndpoint
, tokenEndpoint
, jwksUri
and issuer
as OpenID Provider's configuration information. They should be available in social vendor's documentation.
authenticationEndpoint: This endpoint is used to initiate the authentication process. The authentication process typically involves the user logging in and granting authorization for the client application to access their resources.
tokenEndpoint: This endpoint is used by the client application to obtain an id token that can be used to access the requested resources. The client application typically sends a request to the token endpoint with a grant type and authorization code to receive an id token.
jwksUri: This is the URL endpoint where the JSON Web Key Set (JWKS) of the social identity provider (IdP for short) can be obtained. The JWKS is a set of cryptographic keys that the IdP uses to sign and verify JSON Web Tokens (JWTs) that are issued during the authentication process. The jwksUri
is used by the relying party (RP) to obtain the public keys used by the IdP to sign the JWTs, so the RP can verify the authenticity and integrity of the JWTs received from the IdP.
issuer: This is the unique identifier of the IdP that is used by the RP to verify the JWTs received from the IdP. It is included in the JWTs as the iss
claim (Id token is always a JWT). The issuer value should match the URL of the IdP's authorization server, and it should be a URI that the RP trusts. When the RP receives a JWT, it checks the iss
claim to ensure that it was issued by a trusted IdP, and that the JWT is intended for use with the RP.
Together, jwksUri
and issuer
provide a secure mechanism for the RP to verify the identity of the end-user during the authentication process. By using the public keys obtained from the jwksUri
, the RP can verify the authenticity and integrity of the JWTs issued by the IdP. The issuer value ensures that the RP only accepts JWTs that were issued by a trusted IdP, and that the JWTs are intended for use with the RP.
Since an authentication request is always required, an authRequestOptionalConfig
is provided to wrap all optional configs, you can find details on OIDC Authentication Request. You may also find that nonce
is missing in this config. Since nonce
should identical for each request, we put the generation of nonce
in code implementation. So do not worry about it! Previously mentioned jwksUri
and issuer
are also included in idTokenVerificationConfig
.
You may be curious as to why a standard OIDC protocol supports both the implicit and hybrid flows, yet the Logto connector only supports the authorization flow. It has been determined that the implicit and hybrid flows are less secure than the authorization flow. Due to Logto's focus on security, it only supports the authorization flow for the highest level of security for its users, despite its slightly less convenient nature.
responseType
and grantType
can ONLY be FIXED values with "Authorization Code" flow, so we make them optional and default values will be automatically filled.
ℹ️ Note
For all flow types, we provided an OPTIONAL
customConfig
key to put your customize parameters. Each social identity provider could have their own variant on OIDC standard protocol. If your desired social identity provider strictly stick to OIDC standard protocol, the you do not need to care aboutcustomConfig
.
Config types
Name | Type | Required |
---|---|---|
scope | string | True |
clientId | string | True |
clientSecret | string | True |
authorizationEndpoint | string | True |
tokenEndpoint | string | True |
idTokenVerificationConfig | IdTokenVerificationConfig | True |
authRequestOptionalConfig | AuthRequestOptionalConfig | False |
customConfig | { [key: string]: string } | False |
AuthRequestOptionalConfig properties | Type | Required |
---|---|---|
responseType | string | False |
tokenEndpoint | string | False |
responseMode | string | False |
display | string | False |
prompt | string | False |
maxAge | string | False |
uiLocales | string | False |
idTokenHint | string | False |
loginHint | string | False |
acrValues | string | False |
IdTokenVerificationConfig properties | Type | Required |
---|---|---|
jwksUri | string | True |
issuer | string | string[] | False |
audience | string | string[] | False |
algorithms | string[] | False |
clockTolerance | string | number | False |
crit | { [key: string]: string | boolean } | False |
currentDate | Date | False |
maxTokenAge | string | number | False |
subject | string | False |
typ | string | False |
See here to find more details about IdTokenVerificationConfig
.
Save your configuration
Double check you have filled out necessary values in the Logto connector configuration area. Click "Save and Done" (or "Save changes") and the OIDC connector should be available now.
Enable OIDC connector in Sign-in Experience
Switch to the "Sign-in experience" tab, then click the "Sign-up and sign-in" tab.
If it's the first time you enter the tab, you will see a quick introduction about Sign-in Experience and its basic configuration.
Select "None" for the "Sign-up identifier" to provide minimum sign-up effort for OIDC sign-in, which may increase your conversion rate.
In the "Social sign-in" section, add "Add Social Connector" and choose "OIDC". Then you should be able to see a button with text "Continue with OIDC" in the preview section.
Finally, click "Save changes" on the bottom right corner.
Testing and Validation
Return to your Go app. You should now be able to sign in with OIDC. Enjoy!
Further readings
Protect your API For native and single page apps, you'll need to call one or more API endpoints to retrieve and update data.
Learn more about identifying who's who and keeping your API secure.
User management We know you care about user management and activities, as we also do.
Learn more about how to know your users and see the figures like DAU and MAU graphically.
Localization From one regional business to a global corporate, the willingness to offer the best user experience won't change.
You can change current language phrases or add a new language without friction.
Customer IAM series Our serial blog posts about Customer (or Consumer) Identity and Access Management, from 101 to advanced topics and beyond.