88 lines
2.4 KiB
Go
88 lines
2.4 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.
|
|
|
|
//go:build gc && !purego
|
|
// +build gc,!purego
|
|
|
|
package chacha20poly1305
|
|
|
|
import (
|
|
"encoding/binary"
|
|
|
|
"golang.org/x/crypto/internal/subtle"
|
|
"golang.org/x/sys/cpu"
|
|
)
|
|
|
|
//go:noescape
|
|
func chacha20Poly1305Open(dst []byte, key []uint32, src, ad []byte) bool
|
|
|
|
//go:noescape
|
|
func chacha20Poly1305Seal(dst []byte, key []uint32, src, ad []byte)
|
|
|
|
var (
|
|
useAVX2 = cpu.X86.HasAVX2 && cpu.X86.HasBMI2
|
|
)
|
|
|
|
// setupState writes a ChaCha20 input matrix to state. See
|
|
// https://tools.ietf.org/html/rfc7539#section-2.3.
|
|
func setupState(state *[16]uint32, key *[32]byte, nonce []byte) {
|
|
state[0] = 0x61707865
|
|
state[1] = 0x3320646e
|
|
state[2] = 0x79622d32
|
|
state[3] = 0x6b206574
|
|
|
|
state[4] = binary.LittleEndian.Uint32(key[0:4])
|
|
state[5] = binary.LittleEndian.Uint32(key[4:8])
|
|
state[6] = binary.LittleEndian.Uint32(key[8:12])
|
|
state[7] = binary.LittleEndian.Uint32(key[12:16])
|
|
state[8] = binary.LittleEndian.Uint32(key[16:20])
|
|
state[9] = binary.LittleEndian.Uint32(key[20:24])
|
|
state[10] = binary.LittleEndian.Uint32(key[24:28])
|
|
state[11] = binary.LittleEndian.Uint32(key[28:32])
|
|
|
|
state[12] = 0
|
|
state[13] = binary.LittleEndian.Uint32(nonce[0:4])
|
|
state[14] = binary.LittleEndian.Uint32(nonce[4:8])
|
|
state[15] = binary.LittleEndian.Uint32(nonce[8:12])
|
|
}
|
|
|
|
func (c *chacha20poly1305) seal(dst, nonce, plaintext, additionalData []byte) []byte {
|
|
if !cpu.X86.HasSSSE3 {
|
|
return c.sealGeneric(dst, nonce, plaintext, additionalData)
|
|
}
|
|
|
|
var state [16]uint32
|
|
setupState(&state, &c.key, nonce)
|
|
|
|
ret, out := sliceForAppend(dst, len(plaintext)+16)
|
|
if subtle.InexactOverlap(out, plaintext) {
|
|
panic("chacha20poly1305: invalid buffer overlap")
|
|
}
|
|
chacha20Poly1305Seal(out[:], state[:], plaintext, additionalData)
|
|
return ret
|
|
}
|
|
|
|
func (c *chacha20poly1305) open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
|
|
if !cpu.X86.HasSSSE3 {
|
|
return c.openGeneric(dst, nonce, ciphertext, additionalData)
|
|
}
|
|
|
|
var state [16]uint32
|
|
setupState(&state, &c.key, nonce)
|
|
|
|
ciphertext = ciphertext[:len(ciphertext)-16]
|
|
ret, out := sliceForAppend(dst, len(ciphertext))
|
|
if subtle.InexactOverlap(out, ciphertext) {
|
|
panic("chacha20poly1305: invalid buffer overlap")
|
|
}
|
|
if !chacha20Poly1305Open(out, state[:], ciphertext, additionalData) {
|
|
for i := range out {
|
|
out[i] = 0
|
|
}
|
|
return nil, errOpen
|
|
}
|
|
|
|
return ret, nil
|
|
}
|