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moby--moby/vendor/github.com/docker/swarmkit/manager/encryption/encryption.go
Aaron Lehmann 39433318fe Vendor swarmkit d60ccf3
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
2017-03-07 19:09:21 -08:00

132 lines
3.7 KiB
Go

package encryption
import (
cryptorand "crypto/rand"
"encoding/base64"
"fmt"
"io"
"strings"
"github.com/docker/swarmkit/api"
"github.com/gogo/protobuf/proto"
"github.com/pkg/errors"
)
// This package defines the interfaces and encryption package
const humanReadablePrefix = "SWMKEY-1-"
// ErrCannotDecrypt is the type of error returned when some data cannot be decryptd as plaintext
type ErrCannotDecrypt struct {
msg string
}
func (e ErrCannotDecrypt) Error() string {
return e.msg
}
// A Decrypter can decrypt an encrypted record
type Decrypter interface {
Decrypt(api.MaybeEncryptedRecord) ([]byte, error)
}
// A Encrypter can encrypt some bytes into an encrypted record
type Encrypter interface {
Encrypt(data []byte) (*api.MaybeEncryptedRecord, error)
}
type noopCrypter struct{}
func (n noopCrypter) Decrypt(e api.MaybeEncryptedRecord) ([]byte, error) {
if e.Algorithm != n.Algorithm() {
return nil, fmt.Errorf("record is encrypted")
}
return e.Data, nil
}
func (n noopCrypter) Encrypt(data []byte) (*api.MaybeEncryptedRecord, error) {
return &api.MaybeEncryptedRecord{
Algorithm: n.Algorithm(),
Data: data,
}, nil
}
func (n noopCrypter) Algorithm() api.MaybeEncryptedRecord_Algorithm {
return api.MaybeEncryptedRecord_NotEncrypted
}
// NoopCrypter is just a pass-through crypter - it does not actually encrypt or
// decrypt any data
var NoopCrypter = noopCrypter{}
// Decrypt turns a slice of bytes serialized as an MaybeEncryptedRecord into a slice of plaintext bytes
func Decrypt(encryptd []byte, decrypter Decrypter) ([]byte, error) {
if decrypter == nil {
return nil, ErrCannotDecrypt{msg: "no decrypter specified"}
}
r := api.MaybeEncryptedRecord{}
if err := proto.Unmarshal(encryptd, &r); err != nil {
// nope, this wasn't marshalled as a MaybeEncryptedRecord
return nil, ErrCannotDecrypt{msg: "unable to unmarshal as MaybeEncryptedRecord"}
}
plaintext, err := decrypter.Decrypt(r)
if err != nil {
return nil, ErrCannotDecrypt{msg: err.Error()}
}
return plaintext, nil
}
// Encrypt turns a slice of bytes into a serialized MaybeEncryptedRecord slice of bytes
func Encrypt(plaintext []byte, encrypter Encrypter) ([]byte, error) {
if encrypter == nil {
return nil, fmt.Errorf("no encrypter specified")
}
encryptedRecord, err := encrypter.Encrypt(plaintext)
if err != nil {
return nil, errors.Wrap(err, "unable to encrypt data")
}
data, err := proto.Marshal(encryptedRecord)
if err != nil {
return nil, errors.Wrap(err, "unable to marshal as MaybeEncryptedRecord")
}
return data, nil
}
// Defaults returns a default encrypter and decrypter
func Defaults(key []byte) (Encrypter, Decrypter) {
n := NewNACLSecretbox(key)
return n, n
}
// GenerateSecretKey generates a secret key that can be used for encrypting data
// using this package
func GenerateSecretKey() []byte {
secretData := make([]byte, naclSecretboxKeySize)
if _, err := io.ReadFull(cryptorand.Reader, secretData); err != nil {
// panic if we can't read random data
panic(errors.Wrap(err, "failed to read random bytes"))
}
return secretData
}
// HumanReadableKey displays a secret key in a human readable way
func HumanReadableKey(key []byte) string {
// base64-encode the key
return humanReadablePrefix + base64.RawStdEncoding.EncodeToString(key)
}
// ParseHumanReadableKey returns a key as bytes from recognized serializations of
// said keys
func ParseHumanReadableKey(key string) ([]byte, error) {
if !strings.HasPrefix(key, humanReadablePrefix) {
return nil, fmt.Errorf("invalid key string")
}
keyBytes, err := base64.RawStdEncoding.DecodeString(strings.TrimPrefix(key, humanReadablePrefix))
if err != nil {
return nil, fmt.Errorf("invalid key string")
}
return keyBytes, nil
}