chore: add usage to readme

README.md

@@ -8,3 +8,37 @@ OIDC_CLIENT_SECRET=<client secret>
 OIDC_ISSUE=<issuer url>
 ```
 If these env vars are not present, then depending on configuration, stubs will be used for the endpoints or the program will crash
+
+
+## Usage
+```go
+package main
+
+import (
+	"os"
+
+	"github.com/gin-contrib/sessions"
+	"github.com/gin-contrib/sessions/memstore"
+	"github.com/gin-gonic/gin"
+	"github.com/janishutz/oidclogin"
+)
+
+func main() {
+	r := gin.Default()
+
+	// TODO: Better secret
+	store := memstore.NewStore([]byte("secret"))
+	r.Use(sessions.Sessions("jhid", store))
+
+	oidclogin.Configure(r, os.Getenv("APP_BASE_URL"), "/account", false)
+	r.LoadHTMLGlob("public/*")
+
+	r.GET("/account", oidclogin.EnsureLogin(false), func(ctx *gin.Context) {
+		ctx.HTML(200, "main.tmpl", gin.H{})
+	})
+
+	r.Run()
+}
+```
+This example further needs the environment variable `APP_BASE_URL` set to something like `https://app.example.org`.
+Further, you should create a template file called `main.tmpl` and also copy over the template files in the `public` directory here and edit them.

handlers.go

@@ -10,7 +10,7 @@ import (
 	"golang.org/x/oauth2"
 )
 
-func LoginHandler(c *gin.Context) {
+func loginHandler(c *gin.Context) {
 	// Set up user session
 	state := rand.Text()
 	nonce := rand.Text()
@@ -27,7 +27,7 @@ func LoginHandler(c *gin.Context) {
 	c.Redirect(301, config.AuthCodeURL(state, oidc.Nonce(nonce), oauth2.S256ChallengeOption(codeVerifier)))
 }
 
-func CallbackHandler(c *gin.Context) {
+func callbackHandler(c *gin.Context) {
 	session := sessions.Default(c)
 	state := session.Get("jhid_oauth_state")
 	nonce := session.Get("jhid_oauth_nonce")
@@ -83,14 +83,20 @@ func CallbackHandler(c *gin.Context) {
 	}
 	if err := idToken.Claims(&claims); err != nil {
 		log.Println("Token claims generation failed", err)
-		c.AbortWithStatus(500)
+		c.HTML(500, "oidcerror.tmpl", gin.H{
+			"error": "ERR_AUTH",
+		})
+		c.Abort()
 		return
 	}
 
 	// Verify NONCE
 	if nonce != claims.Nonce {
 		log.Println("Token verificcation failed", err)
-		c.AbortWithStatus(500)
+		c.HTML(500, "oidcerror.tmpl", gin.H{
+			"error": "ERR_AUTH",
+		})
+		c.Abort()
 		return
 	}
 
@@ -126,9 +132,7 @@ func EnsureLogin(redirectFail bool) func(c *gin.Context) {
 				c.Abort()
 				return
 			} else {
-				c.HTML(401, "autherror.tmpl", gin.H{
+				c.HTML(401, "autherror.tmpl", gin.H{})
-					"error": "ERR_AUTH",
-				})
 				c.Abort()
 				return
 			}

main.go

@@ -27,6 +27,7 @@ var (
 	defaultRedirect string
 )
 
+// Configure and set up the login SDK.
 func Configure(r *gin.Engine, app_url string, default_redirect string, stubs_on_unconfigured bool) {
 	issuer := os.Getenv("OIDC_ISSUER")
 	clientID := os.Getenv("OIDC_CLIENT_ID")
@@ -58,8 +59,22 @@ func Configure(r *gin.Engine, app_url string, default_redirect string, stubs_on_
 		Scopes:       []string{oidc.ScopeOpenID, "email", "profile"},
 	}
 
-	r.GET("/auth/v2/login", LoginHandler)
+	r.GET("/auth/v2/login", loginHandler)
-	r.GET("/auth/v2/verify", CallbackHandler)
+	r.GET("/auth/v2/verify", callbackHandler)
 
 	log.Println("[JHID] Configured successfully")
 }
+
+func ErrorHandler() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		c.Next()
+
+		if len(c.Errors) > 0 {
+			log.Println("Error during route:", c.Errors.Last().Err)
+
+			c.JSON(500, gin.H{
+				"error": "Internal Server Error",
+			})
+		}
+	}
+}

public/autherror.tmpl

@@ -0,0 +1,14 @@
+<html>
+    <head>
+        <!-- NOTE: You should definitely host this yourself! (and you can adjust the style that way, too!) -->
+        <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/janishutz/oidclogin/public/style.css">
+    </head>
+    <body>
+        <div class="message-wrapper">
+            <h1>401</h1>
+            <p>Unauthorized</p>
+        </div>
+        <p>You are not authorized to view this page. Please log in</p>
+        <a href="/">Back Home</a>
+    </body>
+</html>

public/oidcerror.tmpl

@@ -1,9 +1,15 @@
 <html>
     <head>
-
+        <!-- NOTE: You should definitely host this yourself! (and you can adjust the style that way, too!) -->
+        <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/janishutz/oidclogin/public/style.css">
     </head>
     <body>
-        <h1>Login Failed!</h1>
+        <div class="message-wrapper">
-        <p>{{ .error }}</p>
+            <h1>500</h1>
+            <p>Internal Server Error</p>
+        </div>
+        <p>There was an error logging you in. Please try again. We are sorry for the inconvenience</p>
+        <a href="/">Back Home</a>
+        <p class="error-msg">{{ .error }}</p>
     </body>
 </html>

public/style.css

@@ -0,0 +1,49 @@
+html,
+body {
+    background-color: #050505;
+    color: #FFFFFF;
+    width: 100vw;
+    height: 100vh;
+    margin: 0;
+    padding: 0;
+}
+
+body {
+    font-family: sans-serif;
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    flex-direction: column;
+}
+
+.message-wrapper {
+    display: flex;
+    justify-content: center;
+    align-items: center;
+}
+
+.message-wrapper h1 {
+    font-size: 10rem;
+}
+
+.message-wrapper p {
+    font-size: 1.5rem;
+}
+
+a {
+    color: white;
+    background-color: #101066;
+    padding: 10px;
+    border-radius: 10px;
+    cursor: pointer;
+}
+
+.error-msg {
+    font-size: 0.8rem;
+    position: fixed;
+    bottom: 10px;
+    left: 0;
+    width: 100vw;
+    text-align: center;
+    color: #888888;
+}