cryptohelpers.go

// Copyright (c) 2017-2021 Ivan Jelincic <parazyd@dyne.org>
//
// This file is part of tordam
//
// 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 tordam

import (
	"crypto/rand"
	"encoding/base64"
	"fmt"
)

// RandomGarbage returns a base64 encoded string of n bytes of entropy.
func RandomGarbage(n int) (string, error) {
	garbage := make([]byte, n)
	read, err := rand.Read(garbage)
	if err != nil {
		return "", err
	}
	if n != read {
		return "", fmt.Errorf("read %d, but requested %d bytes", read, n)
	}
	return base64.StdEncoding.EncodeToString(garbage), nil
}