added login api

config/config.go

@@ -0,0 +1,15 @@
+package config
+
+const MIN_USERNAME_LENGTH = 4
+
+const MAX_USERNAME_LENGTH = 20
+
+const MIN_PASSWORD_LENGTH = 8
+
+const MAX_PASSWORD_LENGTH = 128
+
+const PASSWORD_REGEX = `^[A-Za-z0-9!@#$%^&*(),.?":{}|<>]+$`
+
+const USERNAME_REGEX = `^[a-zA-Z0-9_]+$`
+
+const BCRYPT_COST = 16

database/db.go

@@ -73,3 +73,32 @@ func InsertUser(db *sql.DB, username string, passwordHash string) (string, error
 	}
 	return userId, err
 }
+
+func GetPasswordHash(db *sql.DB, username string) (string, error) {
+	query := `
+    SELECT password_hash FROM Accounts 
+    WHERE LOWER(username) = LOWER($1);
+  `
+
+	var passwordHash string
+	err := db.QueryRow(query, username).Scan(&passwordHash)
+	if err != nil {
+		return "", fmt.Errorf("error getting password: %v", err)
+	}
+
+	return passwordHash, err
+}
+
+func GetUserId(db *sql.DB, username string) (string, error) {
+	query := `
+    SELECT user_id, username AS dbUsername FROM Accounts
+    WHERE LOWER(username) = $1;
+  `
+
+	var dbUsername string
+	err := db.QueryRow(query, username).Scan(&dbUsername, &dbUsername)
+	if err != nil {
+		return "", fmt.Errorf("error getting user id: %v", err)
+	}
+	return dbUsername, err
+}

handlers/auth.go

@@ -1,11 +1,12 @@
 package handlers
 
 import (
+	"fmt"
 	"github.com/gofiber/fiber/v2"
 	"github.com/golang-jwt/jwt/v5"
 	"golang.org/x/crypto/bcrypt"
-	"log"
 	"os"
+	"relay-server/config"
 	"relay-server/database"
 	"relay-server/helpers"
 	"relay-server/models"
@@ -25,12 +26,10 @@ func Signup(c *fiber.Ctx) error {
 		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "password is empty"})
 	}
 
-	// Checks if passwords have valid length and characters
+	// Checks if passwords or username have valid length and characters
 	if !helpers.IsValidPassword(u.Password) {
 		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid password"})
-	}
-	// Checks if username have valid length and characters
-	if !helpers.IsValidUsername(u.Username) {
+	} else if !helpers.IsValidUsername(u.Username) {
 		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid username"})
 	}
 
@@ -41,9 +40,9 @@ func Signup(c *fiber.Ctx) error {
 	}
 
 	// Create password hash
-	passwordHash, err := bcrypt.GenerateFromPassword([]byte(u.Password), bcrypt.DefaultCost)
+	passwordHash, err := bcrypt.GenerateFromPassword([]byte(u.Password), config.BCRYPT_COST)
 	if err != nil {
-		log.Printf("error hashing password: %v", err)
+		fmt.Printf("error hashing password: %v", err)
 		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "internal server error"})
 	}
 
@@ -70,5 +69,60 @@ func Signup(c *fiber.Ctx) error {
 
 	// If everything went well sent username and user_id assigned by database
 	return c.Status(fiber.StatusOK).JSON(fiber.Map{"message": "Successfully signed up", "username": u.Username, "user_id": userId})
-
+}
+
+func Login(c *fiber.Ctx) error {
+	db, _ := database.InitDatabase()
+	u := new(models.LoginStruct)
+
+	if err := c.BodyParser(u); err != nil {
+		return err
+	}
+
+	// Checks if username or passwords are empty
+	if u.Username == "" {
+		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "username is empty"})
+	} else if u.Password == "" {
+		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "password is empty"})
+	}
+
+	// Checks if username or passwords have valid length and characters
+	if !helpers.IsValidUsername(u.Username) {
+		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid username"})
+	} else if !helpers.IsValidPassword(u.Password) {
+		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid password"})
+	}
+
+	// Checks if username exist in database
+	exist, _ := database.CheckUserExists(db, u.Username)
+	if !exist {
+		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "user does not exists"})
+	}
+
+	// Verifies password matching
+	passwordHash, _ := database.GetPasswordHash(db, u.Password)
+	if bcrypt.CompareHashAndPassword([]byte(passwordHash), []byte(u.Password)) != nil {
+		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "invalid password"})
+	}
+
+	userId, err := database.GetUserId(db, u.Username)
+	if err != nil {
+		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "internal server error"})
+	}
+	// Generate token with user id and username
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
+		"user_id":  userId,
+		"username": u.Username,
+	})
+	// Sign token
+	signedToken, err := token.SignedString([]byte(os.Getenv("JWT_SECRET")))
+
+	// Set token to cookies
+	cookie := new(fiber.Cookie)
+	cookie.Name = "token"
+	cookie.Value = signedToken
+	cookie.Expires = time.Now().Add(30 * 24 * time.Hour)
+	cookie.HTTPOnly = true
+
+	return c.Status(fiber.StatusOK).JSON(fiber.Map{"message": "Successfully signed up", "username": u.Username, "user_id": userId})
 }

helpers/filter.go

@@ -2,20 +2,9 @@ package helpers
 
 import (
 	"regexp"
+	"relay-server/config"
 )
 
-const MIN_USERNAME_LENGTH = 4
-
-const MAX_USERNAME_LENGTH = 20
-
-const MIN_PASSWORD_LENGTH = 8
-
-const MAX_PASSWORD_LENGTH = 128
-
-const PASSWORD_REGEX = `^[A-Za-z0-9!@#$%^&*(),.?":{}|<>]+$`
-
-const USERNAME_REGEX = `^[a-zA-Z0-9_]+$`
-
 func IsValidUsername(username interface{}) bool {
 	// Checks if username is type of string
 	strUsername, ok := username.(string)
@@ -23,15 +12,15 @@ func IsValidUsername(username interface{}) bool {
 		return false
 	}
 
-	match, _ := regexp.MatchString(USERNAME_REGEX, strUsername)
+	match, _ := regexp.MatchString(config.USERNAME_REGEX, strUsername)
 	if !match {
 		return false
 	}
 	// Checks if username length is valid
-	if len(strUsername) < MIN_USERNAME_LENGTH {
+	if len(strUsername) < config.MIN_USERNAME_LENGTH {
 		return false
 	}
-	if len(strUsername) > MAX_USERNAME_LENGTH {
+	if len(strUsername) > config.MAX_USERNAME_LENGTH {
 		return false
 	}
 
@@ -44,15 +33,15 @@ func IsValidPassword(password interface{}) bool {
 		return false
 	}
 
-	if len(strPassword) < MIN_PASSWORD_LENGTH {
+	if len(strPassword) < config.MIN_PASSWORD_LENGTH {
 		return false
 	}
 
-	if len(strPassword) > MAX_PASSWORD_LENGTH {
+	if len(strPassword) > config.MAX_PASSWORD_LENGTH {
 		return false
 	}
 
-	match, _ := regexp.MatchString(PASSWORD_REGEX, strPassword)
+	match, _ := regexp.MatchString(config.PASSWORD_REGEX, strPassword)
 	if !match {
 		return false
 	}

main.go

@@ -20,17 +20,18 @@ func main() {
 			log.Fatal(err)
 		}
 	}(db)
+
 	app.Get("/", func(c *fiber.Ctx) error {
 		return c.SendString("Hello, World!")
 	})
 
-	app.Get("/users", func(c *fiber.Ctx) error {
-		users, _ := database.GetUsers(db)
-		return c.JSON(fiber.Map{"users": users})
-	})
+	//app.Get("/users", func(c *fiber.Ctx) error {
+	//	users, _ := database.GetUsers(db)
+	//	return c.JSON(fiber.Map{"users": users})
+	//})
 
 	app.Post("/api/auth/signup", handlers.Signup)
-
+	app.Post("/api/auth/login", handlers.Login)
 	err = app.Listen(":3000")
 	if err != nil {
 		return

models/models.go

@@ -1,5 +1,10 @@
 package models
 
+type LoginStruct struct {
+	Username string `json:"username" xml:"username" form:"username"`
+	Password string `json:"password" xml:"password" form:"password"`
+}
+
 type SignupStruct struct {
 	Username string `json:"username" xml:"username" form:"username"`
 	Password string `json:"password" xml:"password" form:"password"`