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package pages
import (
"context"
"database/sql"
"errors"
"fmt"
"gosten/csrf"
"gosten/form"
"gosten/model"
"gosten/session"
"net/http"
"net/url"
"github.com/go-chi/chi/v5"
"golang.org/x/crypto/bcrypt"
)
type userContextKey struct{}
func getUser(ctx context.Context) model.User {
return ctx.Value(userContextKey{}).(model.User)
}
const (
sessionDuration = 86400 * 7 // 7 days
loginQueryMarker = "next"
)
func setUserInContext(ctx context.Context, uid int32) (context.Context, error) {
u, err := Q.GetUserById(ctx, uid)
if err != nil {
return ctx, err
}
u.Pwd = "" // don't carry pwd around
return context.WithValue(ctx, userContextKey{}, u), nil
}
func RequireAuth(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
s := session.From(r)
if !s.IsNew() && s.Authenticated {
ctx, err := setUserInContext(r.Context(), s.UserID)
if err == nil {
// authenticated --> done
next.ServeHTTP(w, r.WithContext(ctx))
return
}
s.Invalidate()
s.Save(w, r)
}
// redirect to login with next-param
v := url.Values{}
v.Set(loginQueryMarker, r.URL.Path)
redirPath := "/login?" + v.Encode()
http.Redirect(w, r, redirPath, http.StatusFound)
})
}
type user struct {
Name string `form:"options=required,autofocus"`
Password string `form:"type=password;options=required"`
RememberMe bool `form:"type=checkbox;value=y;options=checked"`
form.FormErrors
csrf.CsrfField
}
func Login() Page {
r := chi.NewRouter()
r.Get("/", func(w http.ResponseWriter, r *http.Request) {
if session.From(r).Authenticated {
http.Redirect(w, r, "/", http.StatusFound)
}
u := user{}
u.SetCsrfField(r)
showLoginPage(r, w, u)
})
r.Post("/", handleLogin)
return r
}
func validatePwd(hash, pwd string) bool {
hashB := []byte(hash)
pwdB := []byte(pwd)
return bcrypt.CompareHashAndPassword(hashB, pwdB) == nil
}
func checkLogin(ctx context.Context, user user) (bool, int32) {
dbUser, err := Q.GetUserByName(ctx, user.Name)
if err == nil {
if !validatePwd(dbUser.Pwd, user.Password) {
return false, 0
}
} else if errors.Is(err, sql.ErrNoRows) {
return false, 0
} else {
panic(fmt.Sprintf("Could not load user '%s': %v", user.Name, err))
}
return true, dbUser.ID
}
func handleLogin(w http.ResponseWriter, r *http.Request) {
u := user{}
form.Parse(r, &u)
ok, userId := checkLogin(r.Context(), u)
if !ok {
u.AddError("Password", "Username oder Passwort falsch.")
showLoginPage(r, w, u)
return
}
s := session.From(r)
if u.RememberMe {
s.MaxAge(sessionDuration) // 1 week
} else {
s.MaxAge(0)
}
s.UserID = userId
s.Authenticated = true
s.Save(w, r)
// redirect
next := r.URL.Query().Get(loginQueryMarker)
if next == "" {
next = "/"
}
http.Redirect(w, r, next, http.StatusFound)
}
func showLoginPage(r *http.Request, w http.ResponseWriter, u user) {
render(login(u))(w, r)
}
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