Files
DdnsClient/database.go
2021-02-05 23:57:51 +01:00

163 lines
3.0 KiB
Go

package main
import (
"bytes"
"crypto/rand"
"crypto/sha256"
"crypto/sha512"
"encoding/base64"
"errors"
"github.com/miekg/dns"
log "github.com/sirupsen/logrus"
"github.com/syndtr/goleveldb/leveldb"
"github.com/syndtr/goleveldb/leveldb/util"
"math"
"math/big"
"os"
"path"
"strings"
"time"
"github.com/patrickmn/go-cache"
)
type Database struct {
_db *leveldb.DB
_cache *cache.Cache
_zone string
}
func (d *Database) ExistHost(host string) bool {
ret, err := d._db.Has([]byte("hosts/" + host), nil)
if err != nil {
log.Fatal(err)
}
return ret
}
func (d *Database) DeleteHost(host string) bool {
err := d._db.Delete([]byte("hosts/" + host), nil)
return err == nil
}
func (d *Database) GetExistingHosts(match string) map[string]string {
iter := d._db.NewIterator(util.BytesPrefix([]byte("hosts/" + match)), nil)
ret := make(map[string]string)
for iter.Next() {
hostname := strings.TrimPrefix(string(iter.Key()), "hosts/")
ret[hostname] = string(iter.Value())
}
return ret
}
func (d *Database) Authorize(host string, token_user string) bool {
token, err := d._db.Get([]byte("hosts/" + host), nil)
if err != nil {
return false
}
if len(token) < sha512.Size {
return false
}
if len(token_user) < sha512.Size {
return false
}
if string(token) == token_user {
return true
}
log.Error(string(token), "!=", token_user)
return false
}
func generateToken() string {
maxInt := big.NewInt(math.MaxInt64)
randInt, err := rand.Int(rand.Reader, maxInt)
if err != nil {
log.Fatal(err)
}
h_plain := []byte(randInt.String() + time.Now().String())
h:= sha256.Sum256(h_plain)
for i:=0;i<10000; i++ {
h = sha256.Sum256(h[:])
}
var buf bytes.Buffer
base64.NewEncoder(base64.URLEncoding, &buf).Write(h[:])
return buf.String()
}
func (d *Database) IsBannedHost(host string) bool {
val, ok := d._cache.Get(host)
var counter int
if ok {
counter = val.(int)
if counter > 3 {
return true
} else {
return false
}
} else {
return false
}
}
func (d *Database) IncrementBanHost(host string) {
_, ok := d._cache.Get(host)
if ok {
d._cache.IncrementInt(host,1)
} else {
d._cache.Add(host, 1, cache.DefaultExpiration)
}
}
func (d *Database) CreateHost(host string) (string, error) {
if d.ExistHost(host) {
return "", errors.New("host already existent")
}
if host == "" {
return "", errors.New("given hostname is empty")
}
if _, ok := dns.IsDomainName(host + "." + d._zone); !ok {
return "", errors.New("given hostname is invalid")
}
token := generateToken()
d._db.Put([]byte("hosts/" + host), []byte(token), nil)
return token, nil
}
func CreateDatabase(config *Config) (*Database, error){
_, err := os.Stat(config.DataDir)
if err != nil {
if os.IsNotExist(err) {
os.MkdirAll(config.DataDir, os.ModeDir)
}
}
file := path.Join(config.DataDir, "ddnsService.db")
store, err := leveldb.OpenFile(file, nil)
db := cache.New(5*time.Minute, 10*time.Minute)
if err != nil {
return nil, err
}
return &Database{_db: store, _cache: db}, nil
}