all

getway/main.go

@@ -0,0 +1,215 @@
+package main
+
+import (
+	"crypto/rand"
+	"database/sql"
+	"encoding/base64"
+	"log"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/gin-contrib/cors"
+	"github.com/gin-gonic/gin"
+	"github.com/go-sql-driver/mysql"
+	"github.com/golang-jwt/jwt"
+	"github.com/google/go-github/v32/github"
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/github"
+)
+
+var dbConn *sql.DB
+var jwtSecret = []byte(os.Getenv("JWT_SECRET"))
+
+func main() {
+	initDB()
+
+	router := gin.Default()
+
+	router.Use(cors.New(cors.Config{
+		AllowOrigins:     []string{"http://localhost:8080"},
+		AllowMethods:     []string{"GET", "POST", "PUT", "DELETE", "OPTIONS", "HEAD"},
+		AllowHeaders:     []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
+		AllowCredentials: true,
+	}))
+
+	router.GET("/auth/github", githubLoginHandler)
+	router.GET("/auth/github/callback", githubCallbackHandler)
+
+	router.Run(":8000")
+}
+
+func githubLoginHandler(c *gin.Context) {
+	state := generateState()
+	code := generateCode()
+
+	err := storeStateToDB(state, code)
+	if err != nil {
+		log.Println("Error storing state to DB:", err)
+		c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"message": "Internal server error"})
+		return
+	}
+
+	oauthConfig := &oauth2.Config{
+		ClientID:     os.Getenv("GITHUB_CLIENT_ID"),
+		ClientSecret: os.Getenv("GITHUB_CLIENT_SECRET"),
+		RedirectURL:  "http://localhost:8000/auth/github/callback",
+		Scopes:       []string{"user:email"},
+		Endpoint:     github.Endpoint,
+	}
+
+	url := oauthConfig.AuthCodeURL(state)
+	c.Redirect(http.StatusFound, url)
+}
+
+func githubCallbackHandler(c *gin.Context) {
+	state := c.Query("state")
+	code := c.Query("code")
+
+	if !verifyState(state, code) {
+		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"message": "Invalid state"})
+		return
+	}
+
+	oauthConfig := &oauth2.Config{
+		ClientID:     os.Getenv("GITHUB_CLIENT_ID"),
+		ClientSecret: os.Getenv("GITHUB_CLIENT_SECRET"),
+		RedirectURL:  "http://localhost:8000/auth/github/callback",
+		Scopes:       []string{"user:email"},
+		Endpoint:     github.Endpoint,
+	}
+
+	token, err := oauthConfig.Exchange(c.Request.Context(), code)
+	if err != nil {
+		log.Println("Error exchanging token:", err)
+		c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"message": "Internal server error"})
+		return
+	}
+
+	client := github.NewClient(oauthConfig.Client(c.Request.Context(), token))
+	user, _, err := client.Users.Get(c.Request.Context(), "")
+	if err != nil {
+		log.Println("Error getting user:", err)
+		c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"message": "Internal server error"})
+		return
+	}
+
+	err = storeUserToDB(user)
+	if err != nil {
+		log.Println("Error storing user to DB:", err)
+		c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"message": "Internal server error"})
+		return
+	}
+
+	jwtToken, err := generateJWTToken(user.ID)
+	if err != nil {
+		log.Println("Error generating JWT token:", err)
+		c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"message": "Internal server error"})
+		return
+	}
+
+	c.SetCookie("token", jwtToken, 60*60*24, "/", "localhost", false, true)
+	c.Redirect(http.StatusFound, "http://localhost:8080/#/")
+}
+
+func initDB() {
+	cfg, err := mysql.ParseDSN(os.Getenv("MYSQL_DSN"))
+	if err != nil {
+		log.Fatal("Error parsing MySQL DSN:", err)
+	}
+
+	dbConn, err = sql.Open("mysql", cfg.FormatDSN())
+	if err != nil {
+		log.Fatal("Error opening database:", err)
+	}
+
+	err = dbConn.Ping()
+	if err != nil {
+		log.Fatal("Error connecting to database:", err)
+	}
+
+	log.Println("Database connection established")
+}
+
+func generateState() string {
+	return generateRandomString(20)
+}
+
+func generateCode() string {
+	return generateRandomString(20)
+}
+
+func generateRandomString(length int) string {
+	byteArr := make([]byte, length)
+	_, err := rand.Read(byteArr)
+	if err != nil {
+		log.Fatal("Error generating random string:", err)
+	}
+
+	return base64.URLEncoding.EncodeToString(byteArr)
+}
+
+func storeStateToDB(state, code string) error {
+	query := "INSERT INTO oauth_state (state, code) VALUES (?, ?)"
+	stmt, err := dbConn.Prepare(query)
+	if err != nil {
+		return err
+	}
+	defer stmt.Close()
+
+	_, err = stmt.Exec(state, code)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func verifyState(state, code string) bool {
+	query := "SELECT COUNT(*) FROM oauth_state WHERE state = ? AND code = ?"
+	row := dbConn.QueryRow(query, state, code)
+
+	var count int
+	err := row.Scan(&count)
+	if err != nil {
+		log.Println("Error verifying state:", err)
+		return false
+	}
+
+	if count == 0 {
+		return false
+	}
+
+	return true
+}
+
+func storeUserToDB(user *github.User) error {
+	query := "INSERT INTO users (id, login, email) VALUES (?, ?, ?) ON DUPLICATE KEY UPDATE login = VALUES(login), email = VALUES(email)"
+	stmt, err := dbConn.Prepare(query)
+	if err != nil {
+		return err
+	}
+	defer stmt.Close()
+
+	_, err = stmt.Exec(user.GetID(), user.GetLogin(), user.GetEmail())
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func generateJWTToken(userID int64) (string, error) {
+	token := jwt.New(jwt.SigningMethodHS256)
+
+	claims := token.Claims.(jwt.MapClaims)
+	claims["userID"] = userID
+	claims["exp"] = time.Now().Add(time.Hour * 24).Unix()
+
+	jwtToken, err := token.SignedString(jwtSecret)
+	if err != nil {
+		return "", err
+	}
+
+	return jwtToken, nil
+}