alpha/session.go

85 lines
1.6 KiB
Go

package main
import (
"crypto/rand"
"encoding/base64"
"fmt"
"math"
"time"
)
var ErrInvalidSession = fmt.Errorf("session not found")
type Sess struct {
User User
expr time.Time
}
type Sessions struct {
sessions map[string]Sess
}
func (s *Sessions) Create(user User, expr time.Duration) (string, error) {
if s.sessions == nil {
s.sessions = map[string]Sess{}
}
key := randomStr(24)
s.sessions[key] = Sess{
User: user,
expr: time.Now().Add(expr),
}
return key, nil
}
func (s *Sessions) Get(key string) (User, error) {
if s.sessions == nil {
s.sessions = map[string]Sess{}
return User{}, ErrInvalidSession
}
sess, ok := s.sessions[key]
if !ok {
return User{}, ErrInvalidSession
}
if sess.expr.Before(time.Now()) {
delete(s.sessions, key)
return User{}, ErrInvalidSession
}
return sess.User, nil
}
func (s *Sessions) Refresh(key string, user User, expr time.Duration) error {
if s.sessions == nil {
s.sessions = map[string]Sess{}
return ErrInvalidSession
}
sess, ok := s.sessions[key]
if !ok {
return ErrInvalidSession
}
if sess.expr.Before(time.Now()) {
delete(s.sessions, key)
return ErrInvalidSession
}
s.sessions[key] = Sess{
User: user,
expr: time.Now().Add(expr),
}
return nil
}
func (s *Sessions) Destroy(key string) {
if s.sessions == nil {
s.sessions = map[string]Sess{}
return
}
delete(s.sessions, key)
}
// taken from https://stackoverflow.com/a/55860599
func randomStr(l int) string {
buff := make([]byte, int(math.Ceil(float64(l)/float64(1.33333333333))))
rand.Read(buff)
str := base64.RawURLEncoding.EncodeToString(buff)
return str[:l] // strip 1 extra character we get from odd length results
}