random.go

// Kodex (Community Edition - CE) - Privacy & Security Engineering Platform
// Copyright (C) 2019-2024  KIProtect GmbH (HRB 208395B) - Germany
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package kodex

import (
	"crypto/rand"
	"crypto/sha256"
	"golang.org/x/crypto/pbkdf2"
)

const RANDOM_ID_LENGTH = 16

func RandomID() []byte {
	bytes, err := RandomBytes(RANDOM_ID_LENGTH)
	if err != nil {
		panic(err)
	}
	return bytes
}

func RandomBytes(n int) ([]byte, error) {
	b := make([]byte, n)
	_, err := rand.Read(b)
	// Note that err == nil only if we read len(b) bytes.
	if err != nil {
		return nil, err
	}
	return b, nil
}

func DeriveKey(key, salt []byte, length int) []byte {
	return pbkdf2.Key(key, salt, 4096, length, sha256.New)
}