crypto

Documentation

Index

• Constants
• Variables
• func CiphertextLength(plaintextSize int) int
• func NewBlobBuffer(size int) []byte
• func NewRandomNonce() []byte
• func NewSalt() ([]byte, error)
• func PlaintextLength(ciphertextSize int) int
• type EncryptionKey
  • func (k *EncryptionKey) Valid() bool
• type Key
  • func KDF(p Params, salt []byte, password string) (*Key, error)
  • func NewRandomKey() *Key
  • func (k *Key) NonceSize() int
  • func (k *Key) Open(dst, nonce, ciphertext, _ []byte) ([]byte, error)
  • func (k *Key) Overhead() int
  • func (k *Key) Seal(dst, nonce, plaintext, additionalData []byte) []byte
  • func (k *Key) Valid() bool
• type MACKey
  • func (m *MACKey) Valid() bool
• type Params
  • func Calibrate(timeout time.Duration, memory int) (Params, error)

Constants

const (

	// Extension is the number of bytes a plaintext is enlarged by encrypting it.
	Extension = ivSize + macSize
)

Variables

var DefaultKDFParams = Params{
	N: sscrypt.DefaultParams.N,
	R: sscrypt.DefaultParams.R,
	P: sscrypt.DefaultParams.P,
}

DefaultKDFParams are the default parameters used for Calibrate and KDF().

var (
	// ErrUnauthenticated is returned when ciphertext verification has failed.
	ErrUnauthenticated = fmt.Errorf("ciphertext verification failed")
)

Functions

func CiphertextLength

func CiphertextLength(plaintextSize int) int

CiphertextLength returns the encrypted length of a blob with plaintextSize bytes.

func NewBlobBuffer

func NewBlobBuffer(size int) []byte

NewBlobBuffer returns a buffer that is large enough to hold a blob of size plaintext bytes, including the crypto overhead.

func NewRandomNonce

func NewRandomNonce() []byte

NewRandomNonce returns a new random nonce. It panics on error so that the program is safely terminated.

func NewSalt

func NewSalt() ([]byte, error)

NewSalt returns new random salt bytes to use with KDF(). If NewSalt returns an error, this is a grave situation and the program must abort and terminate.

func PlaintextLength

func PlaintextLength(ciphertextSize int) int

PlaintextLength returns the plaintext length of a blob with ciphertextSize bytes.

Types

type EncryptionKey

type EncryptionKey [32]byte

EncryptionKey is key used for encryption

func (*EncryptionKey) Valid

func (k *EncryptionKey) Valid() bool

Valid tests whether the key k is valid (i.e. not zero).

type Key

type Key struct {
	MACKey        `json:"mac"`
	EncryptionKey `json:"encrypt"`
}

func KDF

func KDF(p Params, salt []byte, password string) (*Key, error)

KDF derives encryption and message authentication keys from the password using the supplied parameters N, R and P and the Salt.

func NewRandomKey

func NewRandomKey() *Key

NewRandomKey returns new encryption and message authentication keys.

func (*Key) NonceSize

func (k *Key) NonceSize() int

NonceSize returns the size of the nonce that must be passed to Seal and Open.

func (*Key) Open

func (k *Key) Open(dst, nonce, ciphertext, _ []byte) ([]byte, error)

func (*Key) Overhead

func (k *Key) Overhead() int

func (*Key) Seal

func (k *Key) Seal(dst, nonce, plaintext, additionalData []byte) []byte

func (*Key) Valid

func (k *Key) Valid() bool

Valid tests if the key is valid.

type MACKey

type MACKey struct {
	K [16]byte // for AES-128
	R [16]byte // for Poly1305
}

MACKey is used to sign (authenticate) data.

func (*MACKey) Valid

func (m *MACKey) Valid() bool

Valid tests whether the key k is valid (i.e. not zero).

type Params

type Params struct {
	N int
	R int
	P int
}

func Calibrate

func Calibrate(timeout time.Duration, memory int) (Params, error)

Calibrate determines new KDF parameters for the current hardware.