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>
74 lines
2.4 KiB
Go
74 lines
2.4 KiB
Go
// Copyright 2016 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package chacha20poly1305
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import (
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"encoding/binary"
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"golang.org/x/crypto/chacha20"
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"golang.org/x/crypto/internal/subtle"
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"golang.org/x/crypto/poly1305"
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)
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func roundTo16(n int) int {
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return 16 * ((n + 15) / 16)
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}
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func (c *chacha20poly1305) sealGeneric(dst, nonce, plaintext, additionalData []byte) []byte {
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ret, out := sliceForAppend(dst, len(plaintext)+poly1305.TagSize)
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if subtle.InexactOverlap(out, plaintext) {
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panic("chacha20poly1305: invalid buffer overlap")
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}
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var polyKey, discardBuf [32]byte
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s, _ := chacha20.NewUnauthenticatedCipher(c.key[:], nonce)
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s.XORKeyStream(polyKey[:], polyKey[:])
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s.XORKeyStream(discardBuf[:], discardBuf[:]) // skip the next 32 bytes
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s.XORKeyStream(out, plaintext)
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polyInput := make([]byte, roundTo16(len(additionalData))+roundTo16(len(plaintext))+8+8)
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copy(polyInput, additionalData)
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copy(polyInput[roundTo16(len(additionalData)):], out[:len(plaintext)])
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binary.LittleEndian.PutUint64(polyInput[len(polyInput)-16:], uint64(len(additionalData)))
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binary.LittleEndian.PutUint64(polyInput[len(polyInput)-8:], uint64(len(plaintext)))
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var tag [poly1305.TagSize]byte
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poly1305.Sum(&tag, polyInput, &polyKey)
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copy(out[len(plaintext):], tag[:])
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return ret
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}
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func (c *chacha20poly1305) openGeneric(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
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var tag [poly1305.TagSize]byte
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copy(tag[:], ciphertext[len(ciphertext)-16:])
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ciphertext = ciphertext[:len(ciphertext)-16]
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var polyKey, discardBuf [32]byte
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s, _ := chacha20.NewUnauthenticatedCipher(c.key[:], nonce)
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s.XORKeyStream(polyKey[:], polyKey[:])
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s.XORKeyStream(discardBuf[:], discardBuf[:]) // skip the next 32 bytes
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polyInput := make([]byte, roundTo16(len(additionalData))+roundTo16(len(ciphertext))+8+8)
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copy(polyInput, additionalData)
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copy(polyInput[roundTo16(len(additionalData)):], ciphertext)
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binary.LittleEndian.PutUint64(polyInput[len(polyInput)-16:], uint64(len(additionalData)))
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binary.LittleEndian.PutUint64(polyInput[len(polyInput)-8:], uint64(len(ciphertext)))
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ret, out := sliceForAppend(dst, len(ciphertext))
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if subtle.InexactOverlap(out, ciphertext) {
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panic("chacha20poly1305: invalid buffer overlap")
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}
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if !poly1305.Verify(&tag, polyInput, &polyKey) {
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for i := range out {
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out[i] = 0
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}
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return nil, errOpen
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}
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s.XORKeyStream(out, ciphertext)
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return ret, nil
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}
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