TagSize is the size, in bytes, of a poly1305 authenticator.
const TagSize = 16
func Sum(out *[16]byte, m []byte, key *[32]byte)
Sum generates an authenticator for m using a one-time key and puts the 16-byte result into out. Authenticating two different messages with the same key allows an attacker to forge messages at will.
func Verify(mac *[16]byte, m []byte, key *[32]byte) bool
Verify returns true if mac is a valid authenticator for m with the given key.
MAC is an io.Writer computing an authentication tag of the data written to it.
MAC cannot be used like common hash.Hash implementations, because using a poly1305 key twice breaks its security. Therefore writing data to a running MAC after calling Sum causes it to panic.
type MAC struct {
// contains filtered or unexported fields
}
func New(key *[32]byte) *MAC
New returns a new MAC computing an authentication tag of all data written to it with the given key. This allows writing the message progressively instead of passing it as a single slice. Common users should use the Sum function instead.
The key must be unique for each message, as authenticating two different messages with the same key allows an attacker to forge messages at will.
func (h *MAC) Size() int
Size returns the number of bytes Sum will return.
func (h *MAC) Sum(b []byte) []byte
Sum computes the authenticator of all data written to the message authentication code.
func (h *MAC) Write(p []byte) (n int, err error)
Write adds more data to the running message authentication code. It never returns an error.
It must not be called after the first call of Sum.