initial commit

database.go

@@ -0,0 +1,162 @@
+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
+
+}