rcw/wrappers/sanityCheck.go

package wrappers

import (
	"bytes"
	"errors"
	"os"
)

// GenSanityCheck creates an encrypted file containing known plaintext
// to later be used for ensuring the user does not encrypt data with
// an incorrect password.
func GenSanityCheck(path string, password []byte, zeroizePassword bool) error {
	err := os.WriteFile(path, Encrypt([]byte("thx4usin'rcw"), password, false, zeroizePassword), 0600)
	return err
}

// RunSanityCheck should be run before any encryption operation
// to ensure the user does not encrypt data with an incorrect password.
// Failure to perform this check could result in data loss.
func RunSanityCheck(path string, password []byte) error {
	encBytes, err := os.ReadFile(path)
	if err != nil {
		return errors.New("unable to read sanity check file (" + path + "): " + err.Error())
	}
	decBytes, err := Decrypt(encBytes, password, false)
	if err == nil {
		if bytes.Equal(decBytes, []byte("thx4usin'rcw")) {
			return nil
		}
	}
	return errors.New("sanity check failed (likely due to inconsistent password)")
}