Filippo Valsorda
e0829623af
const KeySize = 32
const NonceSize = 12
func HChaCha20(key, nonce []byte) ([]byte, error)
type Cipher struct {}
func NewUnauthenticatedCipher(key, nonce []byte) (*Cipher, error)
func (s *Cipher) XORKeyStream(dst, src []byte)
Small performance hit in chacha20poly1305, probably due to the loss
of the Advance API, which we might consider adding later. No new
allocations, thanks to the mid-stack inliner.
name old time/op new time/op delta
Chacha20Poly1305/Open-64-8 1.60µs ± 0% 1.68µs ± 1% +4.94% (p=0.000 n=9+10)
Chacha20Poly1305/Seal-64-8 1.56µs ± 0% 1.64µs ± 1% +5.21% (p=0.000 n=8+10)
Chacha20Poly1305/Open-64-X-8 2.10µs ± 1% 2.22µs ± 1% +5.81% (p=0.000 n=10+10)
Chacha20Poly1305/Seal-64-X-8 2.07µs ± 1% 2.17µs ± 0% +4.88% (p=0.000 n=10+10)
Chacha20Poly1305/Open-1350-8 15.4µs ± 0% 15.7µs ± 1% +1.65% (p=0.000 n=10+10)
Chacha20Poly1305/Seal-1350-8 15.6µs ± 2% 15.9µs ± 1% +1.58% (p=0.028 n=10+9)
Chacha20Poly1305/Open-1350-X-8 16.0µs ± 1% 16.3µs ± 2% +2.00% (p=0.000 n=10+10)
Chacha20Poly1305/Seal-1350-X-8 15.9µs ± 0% 16.3µs ± 1% +1.91% (p=0.000 n=10+8)
Chacha20Poly1305/Open-8192-8 85.6µs ± 0% 86.6µs ± 1% +1.21% (p=0.000 n=10+10)
Chacha20Poly1305/Seal-8192-8 85.7µs ± 0% 86.3µs ± 0% +0.68% (p=0.001 n=9+9)
Chacha20Poly1305/Open-8192-X-8 86.4µs ± 1% 87.1µs ± 1% +0.76% (p=0.035 n=10+9)
Chacha20Poly1305/Seal-8192-X-8 86.0µs ± 0% 87.0µs ± 1% +1.14% (p=0.000 n=9+9)
Updates golang/go#24485
Change-Id: I2ec2ef487a03f013049915d9063751c75a78408b
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/185980
Reviewed-by: Michael Munday <mike.munday@ibm.com>
95 lines
2.6 KiB
Go
95 lines
2.6 KiB
Go
// Copyright 2016 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// Package chacha20poly1305 implements the ChaCha20-Poly1305 AEAD and its
|
|
// extended nonce variant XChaCha20-Poly1305, as specified in RFC 8439 and
|
|
// draft-irtf-cfrg-xchacha-01.
|
|
package chacha20poly1305 // import "golang.org/x/crypto/chacha20poly1305"
|
|
|
|
import (
|
|
"crypto/cipher"
|
|
"errors"
|
|
)
|
|
|
|
const (
|
|
// KeySize is the size of the key used by this AEAD, in bytes.
|
|
KeySize = 32
|
|
|
|
// NonceSize is the size of the nonce used with the standard variant of this
|
|
// AEAD, in bytes.
|
|
//
|
|
// Note that this is too short to be safely generated at random if the same
|
|
// key is reused more than 2³² times.
|
|
NonceSize = 12
|
|
|
|
// NonceSizeX is the size of the nonce used with the XChaCha20-Poly1305
|
|
// variant of this AEAD, in bytes.
|
|
NonceSizeX = 24
|
|
)
|
|
|
|
type chacha20poly1305 struct {
|
|
key [KeySize]byte
|
|
}
|
|
|
|
// New returns a ChaCha20-Poly1305 AEAD that uses the given 256-bit key.
|
|
func New(key []byte) (cipher.AEAD, error) {
|
|
if len(key) != KeySize {
|
|
return nil, errors.New("chacha20poly1305: bad key length")
|
|
}
|
|
ret := new(chacha20poly1305)
|
|
copy(ret.key[:], key)
|
|
return ret, nil
|
|
}
|
|
|
|
func (c *chacha20poly1305) NonceSize() int {
|
|
return NonceSize
|
|
}
|
|
|
|
func (c *chacha20poly1305) Overhead() int {
|
|
return 16
|
|
}
|
|
|
|
func (c *chacha20poly1305) Seal(dst, nonce, plaintext, additionalData []byte) []byte {
|
|
if len(nonce) != NonceSize {
|
|
panic("chacha20poly1305: bad nonce length passed to Seal")
|
|
}
|
|
|
|
if uint64(len(plaintext)) > (1<<38)-64 {
|
|
panic("chacha20poly1305: plaintext too large")
|
|
}
|
|
|
|
return c.seal(dst, nonce, plaintext, additionalData)
|
|
}
|
|
|
|
var errOpen = errors.New("chacha20poly1305: message authentication failed")
|
|
|
|
func (c *chacha20poly1305) Open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
|
|
if len(nonce) != NonceSize {
|
|
panic("chacha20poly1305: bad nonce length passed to Open")
|
|
}
|
|
if len(ciphertext) < 16 {
|
|
return nil, errOpen
|
|
}
|
|
if uint64(len(ciphertext)) > (1<<38)-48 {
|
|
panic("chacha20poly1305: ciphertext too large")
|
|
}
|
|
|
|
return c.open(dst, nonce, ciphertext, additionalData)
|
|
}
|
|
|
|
// sliceForAppend takes a slice and a requested number of bytes. It returns a
|
|
// slice with the contents of the given slice followed by that many bytes and a
|
|
// second slice that aliases into it and contains only the extra bytes. If the
|
|
// original slice has sufficient capacity then no allocation is performed.
|
|
func sliceForAppend(in []byte, n int) (head, tail []byte) {
|
|
if total := len(in) + n; cap(in) >= total {
|
|
head = in[:total]
|
|
} else {
|
|
head = make([]byte, total)
|
|
copy(head, in)
|
|
}
|
|
tail = head[len(in):]
|
|
return
|
|
}
|