func (k Key) isZero() bool {
	return k == Key{}
}
isZero reports whether the key consists entirely of zeros.
package bakery
import (
	"crypto/rand"
	"encoding/base64"
	"encoding/json"
	"strings"
	"sync"
	"golang.org/x/crypto/nacl/box"
	"golang.org/x/net/context"
	"gopkg.in/errgo.v1"
	"gopkg.in/macaroon.v2"
)
const KeyLen = 32
const NonceLen = 24
type PublicKey struct {
	Key
}
type PrivateKey struct {
	Key
}
type Key [KeyLen]byte
func (k Key) String() string {
	return base64.StdEncoding.EncodeToString(k[:])
}
func (k Key) MarshalBinary() ([]byte, error) {
	return k[:], nil
}