Move all the code to a lib folder

lib/database/users.go

@@ -0,0 +1,137 @@
+package database
+
+import (
+	log "github.com/cihub/seelog"
+
+	"bytes"
+	"crypto/rand"
+	"errors"
+
+	"golang.org/x/crypto/scrypt"
+	"gopkg.in/mgo.v2"
+	"gopkg.in/mgo.v2/bson"
+)
+
+const (
+	user_coll = "users"
+	pass_salt = "ImperialLibSalt"
+)
+
+type User struct {
+	user db_user
+	err  error
+	coll *mgo.Collection
+}
+
+type db_user struct {
+	User string
+	Pass []byte
+	Salt []byte
+	Role string
+}
+
+func getUser(coll *mgo.Collection, name string) *User {
+	u := new(User)
+	if !validUserName(name) {
+		u.err = errors.New("Invalid username")
+		return u
+	}
+
+	u.coll = coll
+	err := u.coll.Find(bson.M{"user": name}).One(&u.user)
+	if err != nil {
+		log.Warn("Error on database checking user ", name, ": ", err)
+		u.err = errors.New("User not found")
+		return u
+	}
+	return u
+}
+
+func addUser(coll *mgo.Collection, name string, pass string) error {
+	if !validUserName(name) {
+		return errors.New("Invalid user name")
+	}
+	num, err := coll.Find(bson.M{"user": name}).Count()
+	if err != nil {
+		log.Error("Error on database checking user ", name, ": ", err)
+		return errors.New("An error happen on the database")
+	}
+	if num != 0 {
+		return errors.New("User name already exist")
+	}
+
+	var user db_user
+	user.Pass, user.Salt, err = hashPass(pass)
+	if err != nil {
+		log.Error("Error hashing password: ", err)
+		return errors.New("An error happen storing the password")
+	}
+	user.User = name
+	user.Role = ""
+	return coll.Insert(user)
+}
+
+func validUserName(name string) bool {
+	return name != ""
+}
+
+func (u User) Valid(pass string) bool {
+	if u.err != nil {
+		return false
+	}
+	return validatePass(pass, u.user)
+}
+
+func (u User) Role() string {
+	return u.user.Role
+}
+
+func (u *User) SetPassword(pass string) error {
+	if u.err != nil {
+		return u.err
+	}
+	hash, salt, err := hashPass(pass)
+	if err != nil {
+		return err
+	}
+	return u.coll.Update(bson.M{"user": u.user.User}, bson.M{"$set": bson.M{"pass": hash, "salt": salt}})
+}
+
+func hashPass(pass string) (hash []byte, salt []byte, err error) {
+	salt, err = genSalt()
+	if err != nil {
+		return
+	}
+	hash, err = calculateHash(pass, salt)
+	return
+}
+
+func genSalt() ([]byte, error) {
+	const (
+		saltLen = 64
+	)
+
+	b := make([]byte, saltLen)
+	_, err := rand.Read(b)
+	return b, err
+}
+
+func validatePass(pass string, user db_user) bool {
+	hash, err := calculateHash(pass, user.Salt)
+	if err != nil {
+		return false
+	}
+	return bytes.Compare(user.Pass, hash) == 0
+}
+
+func calculateHash(pass string, salt []byte) ([]byte, error) {
+	const (
+		N      = 16384
+		r      = 8
+		p      = 1
+		keyLen = 32
+	)
+
+	bpass := []byte(pass)
+	return scrypt.Key(bpass, salt, N, r, p, keyLen)
+}