feat: users & authentication implementation

api/auth.go

@@ -0,0 +1,133 @@
+package api
+
+import (
+	"GohCMS2/useCases"
+	"encoding/json"
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/jwtauth/v5"
+	"golang.org/x/crypto/bcrypt"
+	"net/http"
+	"time"
+)
+
+type UserRegister struct {
+	Username string `json:"username" validate:"required,min=3,max=20"`
+	Password string `json:"password" validate:"required,min=8"`
+	Email    string `json:"email" validate:"required,email"`
+}
+
+type UserLogin struct {
+	Username string `json:"username" validate:"required,min=3,max=20"`
+	Password string `json:"password" validate:"required,min=8"`
+}
+
+var TokenAuth *jwtauth.JWTAuth
+
+const logsErrorMessage = "Access to the requested resource is forbidden due to incorrect password and/or username."
+const bodyErrorMessage = "The request cannot be processed due to a mismatch in the format of the body."
+
+func SetJwtCookie(w *http.ResponseWriter, userId uint32) error {
+	_, tokenString, err := TokenAuth.Encode(map[string]interface{}{"user_id": userId})
+	if err != nil {
+		return err
+	}
+	http.SetCookie(*w, &http.Cookie{
+		Name:     "jwt",
+		Value:    tokenString,
+		Expires:  time.Now().Add(24 * time.Hour),
+		Secure:   false, // TODO false in dev, true in prod
+		HttpOnly: true,
+		Path:     "/v1/",
+	})
+	return nil
+}
+
+func isAllowedToCreateUser() bool {
+	users := container.ListUsersUseCase.ListUsers()
+	return len(users) == 0
+}
+
+func isLoggedIn(r *http.Request) bool {
+	token, err := jwtauth.VerifyRequest(
+		TokenAuth,
+		r,
+		jwtauth.TokenFromCookie,
+		jwtauth.TokenFromHeader,
+		jwtauth.TokenFromQuery)
+	return token != nil && err == nil
+}
+
+func login(w http.ResponseWriter, r *http.Request) {
+	var user UserLogin
+
+	err := json.NewDecoder(r.Body).Decode(&user)
+	if err != nil {
+		http.Error(w, bodyErrorMessage, http.StatusBadRequest)
+		return
+	}
+
+	err = validate.Struct(user)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	dbUser, err := container.GetUserByUsernameUseCase.GetUserByUsername(user.Username)
+	if err != nil {
+		http.Error(w, logsErrorMessage, http.StatusForbidden)
+		return
+	}
+
+	err = bcrypt.CompareHashAndPassword([]byte(dbUser.Password), []byte(user.Password))
+	if err != nil {
+		http.Error(w, logsErrorMessage, http.StatusForbidden)
+		return
+	}
+
+	_ = SetJwtCookie(&w, dbUser.ID)
+
+	message, _ := json.Marshal(map[string]interface{}{"message": "User logged in! HTTPonly access_token cookie created"})
+	_, _ = w.Write(message)
+}
+
+func register(w http.ResponseWriter, r *http.Request) {
+	if !isLoggedIn(r) && !isAllowedToCreateUser() {
+		http.Error(w, "You are not allowed to create a user. Log in or reset database.", http.StatusForbidden)
+		return
+	}
+
+	var user UserRegister
+	err := json.NewDecoder(r.Body).Decode(&user)
+	if err != nil {
+		http.Error(w, bodyErrorMessage, http.StatusBadRequest)
+		return
+	}
+
+	err = validate.Struct(user)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	createdUser, err := container.CreateUserUseCase.CreateUser(useCases.CreateUserCommand{
+		Username: user.Username,
+		Password: user.Password,
+		Email:    user.Email,
+	})
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	err = SetJwtCookie(&w, createdUser.ID)
+
+	message, _ := json.Marshal(map[string]interface{}{"message": "User registered! HTTPonly access_token cookie created"})
+	_, err = w.Write(message)
+}
+
+func NewAuthRouter() http.Handler {
+	r := chi.NewRouter()
+	r.Post("/register", register)
+	r.Post("/login", login)
+	return r
+}