-- import "vimagination.zapto.org/authenticate"

Package authenticate provides a simple interface to encrypt and authenticate a

var (
	ErrInvalidAES  = errors.New("invalid AES key, must be 16, 24 or 32 bytes")
	ErrInvalidData = errors.New("invalid cipher text")
	ErrExpired     = errors.New("data expired")
)

Errors

type Codec struct {
}

Codec represents an initilised encoder/decoder

func NewCodec(key []byte, maxAge time.Duration) (*Codec, error)

NewCodec takes the encryption key, which should be 16, 24 or 32 bytes long, and an optional duration to create a new Codec.

The optional Duration is used to only allow messages to only be valid while it is younger than the given time.

func (c *Codec) Decode(cipherText, dst []byte) ([]byte, error)

Decode takes a ciphertext slice and a destination buffer and returns the decrypted data or an error if the ciphertext is invalid or expired.

If the destination buffer is too small, or nil, it will be allocated accordingly.

func (c *Codec) Encode(data, dst []byte) []byte

Encode takes a data slice and a destination buffer and returns the encrypted data.

If the destination buffer is too small, or nil, it will be allocated accordingly.

func (c *Codec) Overhead() int

Overhead returns the maximum number of bytes that the ciphertext will be longer than the plain text