streamcrypt

Documentation

Overview

Package streamcrypt provides streaming symmetric encryption using XChaCha20 or AES256-CTR for encryption, SHAKE256 for message authentication, and Argon2 for key derivation.

Index

• Variables
• func Decrypt(ciphertext []byte, passFunc PasswordFunc, options ...Option) ([]byte, error)
• func Encrypt(plaintext []byte, password []byte, options ...Option) []byte
• type Decryptor
  • func NewDecryptor(src io.Reader, passFunc PasswordFunc, options ...Option) *Decryptor
  • func (d *Decryptor) Close() error
  • func (d *Decryptor) Read(b []byte) (int, error)
• type Encryptor
  • func NewEncryptor(dest io.Writer, password []byte, options ...Option) *Encryptor
  • func (e *Encryptor) Close() error
  • func (e *Encryptor) Write(plaintext []byte) (int, error)
• type Mode
  • func (m Mode) String() string
• type Option
  • func WithArgonMemory(mem uint32) Option
  • func WithArgonMemoryMax(mem uint32) Option
  • func WithArgonThreads(n uint8) Option
  • func WithArgonThreadsMax(n uint8) Option
  • func WithArgonTime(time uint32) Option
  • func WithArgonTimeMax(time uint32) Option
  • func WithMode(mode Mode) Option
• type PasswordFunc

Variables

var (
	ErrBadChecksum = errors.New("bad checksum")
	ErrClosed      = errors.New("already closed")
)

var (
	ErrUnsupportedMode        = errors.New("incorrect or unsupported encryption mode")
	ErrHeaderParamsOutOfRange = errors.New("header params out of range")
)

Functions

func Decrypt

func Decrypt(ciphertext []byte, passFunc PasswordFunc, options ...Option) ([]byte, error)

func Encrypt

func Encrypt(
	plaintext []byte,
	password []byte,
	options ...Option,
) []byte

Types

type Decryptor

type Decryptor struct {
	// contains filtered or unexported fields
}

Decryptor is returned by NewDecryptor. See it's documentation for details.

Decryptor implements io.ReadCloser.

func NewDecryptor

func NewDecryptor(
	src io.Reader,
	passFunc PasswordFunc,
	options ...Option,
) *Decryptor

NewDecryptor returns a Decryptor which is an io.ReadCloser that reads ciphertext from src and retrieves the plaintext.

The encryption password is retrieved using passFunc during the first read. The []byte that passFunc returns is zeroed after use, so return a copy of it if it's in use elsewhere.

The authentication of the ciphertext is checked upon reaching EOF or calling Decryptor.Close. Therefore, calling Close after reaching EOF is unnecessary.

After either reaching EOF or calling Close, calls to Read will result in an ErrClosed error, and calls to Close will be a no-op.

The following options can be used to configure the decryption behavior:

• WithArgonTimeMax (default: 10)
• WithArgonMemoryMax (default: 64*1024)
• WithArgonThreadsMax (default: 64)

func (*Decryptor) Close

func (d *Decryptor) Close() error

func (*Decryptor) Read

func (d *Decryptor) Read(b []byte) (int, error)

type Encryptor

type Encryptor struct {
	// contains filtered or unexported fields
}

Encryptor is returned by NewEncryptor. See it's documentation for details.

Encryptor implements io.WriteCloser.

func NewEncryptor

func NewEncryptor(
	dest io.Writer,
	password []byte,
	options ...Option,
) *Encryptor

NewEncryptor returns an Encryptor which is an io.WriteCloser that encrypts plaintext and writes the ciphertext to dest.

Encryptor.Close must be called after all writes are concluded in order to write the authentication bytes to dest.

The password is not retained by this function.

The following options can be used to configure the encryption behavior:

• WithMode (default: ModeXChaCha20)
• WithArgonTime (default: 3)
• WithArgonMemory (default: 16*1024)
• WithArgonThreads (default: 8)

func (*Encryptor) Close

func (e *Encryptor) Close() error

func (*Encryptor) Write

func (e *Encryptor) Write(plaintext []byte) (int, error)

type Mode

type Mode uint8

const (

	////
	ModeXChaCha20 Mode
	ModeAES256CTR
)

func (Mode) String

func (m Mode) String() string

type Option

type Option func(*config)

func WithArgonMemory

func WithArgonMemory(mem uint32) Option

func WithArgonMemoryMax

func WithArgonMemoryMax(mem uint32) Option

func WithArgonThreads

func WithArgonThreads(n uint8) Option

func WithArgonThreadsMax

func WithArgonThreadsMax(n uint8) Option

func WithArgonTime

func WithArgonTime(time uint32) Option

func WithArgonTimeMax

func WithArgonTimeMax(time uint32) Option

func WithMode

func WithMode(mode Mode) Option

type PasswordFunc

type PasswordFunc func() ([]byte, error)

PasswordFunc is used by NewDecryptor. See it's documentation for details.

The returned []byte is zeroed after use, so return a copy of it if it's in use elsewhere.