119 lines
2 KiB
Go
119 lines
2 KiB
Go
// Copyright (C) 2022 Marius Schellenberger
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package server
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import (
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"crypto/hmac"
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"crypto/rand"
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"crypto/sha256"
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"encoding/hex"
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"io"
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weakrand "math/rand"
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"sync"
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"time"
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"git.giftfish.de/ston1th/goacc/pkg/db"
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)
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type AuthValidator interface {
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Login(username, password string) (auth bool)
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}
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const cacheSize = 100
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func init() {
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weakrand.Seed(time.Now().UnixNano())
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}
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type DBLoginValidator struct {
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db *db.DB
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}
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func NewDBLoginValidator(db *db.DB) *DBLoginValidator {
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return &DBLoginValidator{db}
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}
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func (val *DBLoginValidator) Login(username, password string) bool {
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_, err := val.db.Login(username, password)
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return err == nil
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}
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type cache struct {
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mu sync.RWMutex
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m map[string]bool
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}
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func newCache() *cache {
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return &cache{m: make(map[string]bool)}
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}
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func (c *cache) get(k string) (v, ok bool) {
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c.mu.RLock()
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defer c.mu.RUnlock()
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v, ok = c.m[k]
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return
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}
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func (c *cache) set(k string, v bool) {
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c.mu.Lock()
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defer c.mu.Unlock()
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c.makeRoom()
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c.m[k] = v
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}
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func (c *cache) makeRoom() {
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n := len(c.m)
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if n < cacheSize {
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return
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}
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del := n / 10
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if del < 1 {
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del = 1
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}
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for i := 0; i <= del; i++ {
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rnd := weakrand.Intn(len(c.m))
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j := 0
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for k := range c.m {
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if j == rnd {
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delete(c.m, k)
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break
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}
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j++
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}
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}
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}
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type BasicAuth struct {
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mu sync.Mutex
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auth AuthValidator
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cache *cache
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key []byte
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}
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func NewBasicAuth(auth AuthValidator) (*BasicAuth, error) {
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key := make([]byte, 32)
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_, err := io.ReadFull(rand.Reader, key)
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return &BasicAuth{
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auth: auth,
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cache: newCache(),
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key: key,
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}, err
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}
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func (a *BasicAuth) genkey(username, password string) string {
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h := hmac.New(sha256.New, a.key)
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h.Write(append([]byte(username), []byte(password)...))
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return hex.EncodeToString(h.Sum(nil))
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}
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func (a *BasicAuth) Auth(username, password string) (auth bool) {
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k := a.genkey(username, password)
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auth, ok := a.cache.get(k)
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if !ok {
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a.mu.Lock()
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auth = a.auth.Login(username, password)
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a.mu.Unlock()
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a.cache.set(k, auth)
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}
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return
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}
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