From eac592da94bad69c944917df8679663030ce2490 Mon Sep 17 00:00:00 2001
From: kekskurse <git@ekskurse.de>
Date: Thu, 26 Sep 2024 11:00:50 +0200
Subject: [PATCH] easyauth

---
 Readme.md   |   5 +++
 easyauth.go | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 go.mod      |   7 +++-
 go.sum      |   2 +
 4 files changed, 115 insertions(+), 2 deletions(-)
 create mode 100644 easyauth.go

diff --git a/Readme.md b/Readme.md
index 890b5bd..ba62f8f 100644
--- a/Readme.md
+++ b/Readme.md
@@ -1,6 +1,11 @@
 Small oAuth2 Client to have an easy way to connect to Authentik
 # Auth
 
+## Easy Auth
+Easy Authentification for default go http lib.
+
+In Process
+
 ## Low Level Lib / AuthClient
 The Low Level Lib (Auth) is a Client to provied the basic oAuth2 functions without state. 
 
diff --git a/easyauth.go b/easyauth.go
new file mode 100644
index 0000000..e5d364e
--- /dev/null
+++ b/easyauth.go
@@ -0,0 +1,103 @@
+package kekskurseauth
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+type EasyAuth struct {
+	client    Auth
+	jwtSecret []byte
+}
+
+type UserClaims struct {
+	jwt.RegisteredClaims
+	User AuthentikUser
+}
+
+func NewEasyAuth(client Auth) (EasyAuth, error) {
+	e := EasyAuth{}
+	e.client = client
+	e.jwtSecret = []byte("hsajedogö")
+	return e, nil
+}
+
+func (e EasyAuth) GetUser(w http.ResponseWriter, r *http.Request) (AuthentikUser, bool, error) {
+	if r.Method == http.MethodGet {
+		SetCookie(w, "url", r.URL.String(), time.Now().Add(1*time.Minute))
+	}
+	cookie, err := r.Cookie("jwt")
+	if err != nil {
+		return AuthentikUser{}, false, err
+	}
+
+	redirectURL, err := e.client.GetAuthorizationURL("")
+	if err != nil {
+		return AuthentikUser{}, false, err
+	}
+
+	if cookie.Value == "" {
+		http.Redirect(w, r, redirectURL, http.StatusTemporaryRedirect)
+		return AuthentikUser{}, false, nil
+	}
+
+	parsedAccessToken, _ := jwt.ParseWithClaims(cookie.Value, &UserClaims{}, func(token *jwt.Token) (interface{}, error) {
+		return e.jwtSecret, nil
+	})
+
+	claims := parsedAccessToken.Claims.(*UserClaims)
+
+	return claims.User, true, nil
+}
+
+func (e EasyAuth) AuthHTTPHandler(w http.ResponseWriter, r *http.Request) {
+	token, err := e.client.GetTokenFromCode(r.URL.Query().Get("code"))
+	if err != nil {
+		panic(err) // TODO: Deal with error
+	}
+
+	user := AuthentikUser{}
+	err = e.client.GetUserInfo(token.AccessToken, &user)
+	if err != nil {
+		panic(err) // TODO: Deal with error
+	}
+
+	expired := time.Now().Add(5 * time.Minute)
+
+	claims := UserClaims{}
+	claims.Issuer = "EasyAuth"
+	claims.Subject = user.Nickname
+	claims.IssuedAt = jwt.NewNumericDate(time.Now())
+	claims.ExpiresAt = jwt.NewNumericDate(expired)
+	claims.NotBefore = jwt.NewNumericDate(time.Now())
+	claims.User = user
+
+	jwtToken := jwt.NewWithClaims(jwt.SigningMethodHS512, claims)
+	jwtString, err := jwtToken.SignedString(e.jwtSecret)
+	if err != nil {
+		panic(err) // TODO: Deal with error
+	}
+
+	SetCookie(w, "jwt", jwtString, expired)
+
+	_, err = w.Write([]byte("ok")) // TODO: Redirect to right page
+	if err != nil {
+		panic(err) // TODO: Deal with error
+	}
+}
+
+func SetCookie(w http.ResponseWriter, name, value string, expired time.Time) {
+	cookie := http.Cookie{}
+	cookie.Name = name
+	cookie.Value = value
+	cookie.Expires = expired
+	cookie.Path = "/"
+	cookie.MaxAge = int(time.Until(expired).Seconds())
+	cookie.Secure = true
+	cookie.HttpOnly = true
+	cookie.SameSite = http.SameSiteStrictMode
+
+	http.SetCookie(w, &cookie)
+}
diff --git a/go.mod b/go.mod
index 2a86f7a..3e9a163 100644
--- a/go.mod
+++ b/go.mod
@@ -1,8 +1,11 @@
-module git.keks.cloud/kekskurse/kekskurse-auth
+module git.keks.cloud/kekskurse/auth
 
 go 1.23.1
 
-require github.com/stretchr/testify v1.9.0
+require (
+	github.com/golang-jwt/jwt/v5 v5.2.1
+	github.com/stretchr/testify v1.9.0
+)
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
diff --git a/go.sum b/go.sum
index 60ce688..61da7a6 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,7 @@
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/golang-jwt/jwt/v5 v5.2.1 h1:OuVbFODueb089Lh128TAcimifWaLhJwVflnrgM17wHk=
+github.com/golang-jwt/jwt/v5 v5.2.1/go.mod h1:pqrtFR0X4osieyHYxtmOUWsAWrfe1Q5UVIyoH402zdk=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=