feat: add basic SDK

handlers.go

@@ -0,0 +1,112 @@
+package oidclogin
+
+import (
+	"crypto/rand"
+	"log"
+
+	"github.com/coreos/go-oidc/v3/oidc"
+	"github.com/gin-contrib/sessions"
+	"github.com/gin-gonic/gin"
+	"golang.org/x/oauth2"
+)
+
+func LoginHandler(c *gin.Context) {
+	// Set up user session
+	state := rand.Text()
+	nonce := rand.Text()
+	codeVerifier := oauth2.GenerateVerifier()
+	session := sessions.Default(c)
+	session.Set("jhid_oauth_state", state)
+	session.Set("jhid_oauth_nonce", nonce)
+	session.Set("jhid_oauth_code_verifier", codeVerifier)
+	session.Save()
+	c.Redirect(301, config.AuthCodeURL(state, oidc.Nonce(nonce), oauth2.S256ChallengeOption(codeVerifier)))
+}
+
+func CallbackHandler(c *gin.Context) {
+	session := sessions.Default(c)
+	state := session.Get("jhid_oauth_state")
+	nonce := session.Get("jhid_oauth_nonce")
+	codeVerifier := session.Get("jhid_oauth_code_verifier").(string)
+
+	if c.Query("state") != state {
+		log.Println("State invalid")
+		// TODO: Proper pages
+		c.HTML(500, "oidcerror.tmpl", gin.H{
+			"error": "",
+		})
+		c.AbortWithStatus(500)
+		return
+	}
+
+	// Token exchange
+	tok, err := config.Exchange(c, c.Query("code"), oauth2.VerifierOption(codeVerifier))
+	if err != nil {
+		log.Println("Token exchange failed with error", err)
+		c.AbortWithStatus(500)
+		return
+	}
+
+	// Extract ID token
+	rawIdToken, ok := tok.Extra("id_token").(string)
+	if !ok {
+		log.Println("Failed to get ID token", err)
+		c.AbortWithStatus(500)
+		return
+	}
+	idToken, err := verifier.Verify(c, rawIdToken)
+	if err != nil {
+		log.Println("Token verification failed", err)
+		c.AbortWithStatus(500)
+		return
+	}
+
+	// Get claims
+	var claims struct {
+		Uid   string `json:"sub"`
+		Email string `json:"email"`
+		Name  string `json:"name"`
+		Nonce string `json:"nonce"`
+	}
+	if err := idToken.Claims(&claims); err != nil {
+		log.Println("Token claims generation failed", err)
+		c.AbortWithStatus(500)
+		return
+	}
+
+	// Verify NONCE
+	if nonce != claims.Nonce {
+		log.Println("Token verificcation failed", err)
+		c.AbortWithStatus(500)
+		return
+	}
+
+	if userFunc != nil {
+		userFunc(claims.Uid, claims.Name, claims.Email)
+	}
+
+	session.Delete("jhid_oauth_nonce")
+	session.Delete("jhid_oauth_state")
+	session.Delete("jhid_oauth_code_verifier")
+
+	session.Set("jhid_auth", true)
+	session.Save()
+}
+
+func EnsureLogin(redirectFail bool) func(c *gin.Context) {
+	return (func(c *gin.Context) {
+		session := sessions.Default(c)
+		if session.Get("jhid_auth") == true {
+			c.Next()
+		} else {
+			if redirectFail {
+				c.Redirect(307, "/auth/v2/login")
+				c.Abort()
+				return
+			} else {
+				c.AbortWithStatus(401)
+				return
+			}
+		}
+	})
+}