ChaCha20 stream cipher

pull/97/head
v2ray 9 years ago
parent 9e06048ec6
commit 769af1ed02

@ -0,0 +1,49 @@
package crypto_test
import (
"crypto/cipher"
"testing"
. "github.com/v2ray/v2ray-core/common/crypto"
)
const benchSize = 1024 * 1024
func benchmarkStream(b *testing.B, c cipher.Stream) {
b.SetBytes(benchSize)
input := make([]byte, benchSize)
output := make([]byte, benchSize)
for i := 0; i < b.N; i++ {
c.XORKeyStream(output, input)
}
}
func BenchmarkChaCha20(b *testing.B) {
key := make([]byte, 32)
nonce := make([]byte, 8)
c := NewChaCha20Stream(key, nonce)
benchmarkStream(b, c)
}
func BenchmarkChaCha20IETF(b *testing.B) {
key := make([]byte, 32)
nonce := make([]byte, 12)
c := NewChaCha20Stream(key, nonce)
benchmarkStream(b, c)
}
func BenchmarkAESEncryption(b *testing.B) {
key := make([]byte, 32)
iv := make([]byte, 16)
c, _ := NewAesEncryptionStream(key, iv)
benchmarkStream(b, c)
}
func BenchmarkAESDecryption(b *testing.B) {
key := make([]byte, 32)
iv := make([]byte, 16)
c, _ := NewAesDecryptionStream(key, iv)
benchmarkStream(b, c)
}

@ -0,0 +1,11 @@
package crypto
import (
"crypto/cipher"
"github.com/v2ray/v2ray-core/common/crypto/internal"
)
func NewChaCha20Stream(key []byte, iv []byte) cipher.Stream {
return internal.NewChaCha20Stream(key, iv, 20)
}

@ -0,0 +1,57 @@
package crypto_test
import (
"encoding/hex"
"testing"
. "github.com/v2ray/v2ray-core/common/crypto"
v2testing "github.com/v2ray/v2ray-core/testing"
"github.com/v2ray/v2ray-core/testing/assert"
)
func mustDecodeHex(s string) []byte {
b, err := hex.DecodeString(s)
if err != nil {
panic(err)
}
return b
}
func TestChaCha20Stream(t *testing.T) {
v2testing.Current(t)
var cases = []struct {
key []byte
iv []byte
output []byte
}{
{
key: mustDecodeHex("0000000000000000000000000000000000000000000000000000000000000000"),
iv: mustDecodeHex("0000000000000000"),
output: mustDecodeHex("76b8e0ada0f13d90405d6ae55386bd28bdd219b8a08ded1aa836efcc8b770dc7" +
"da41597c5157488d7724e03fb8d84a376a43b8f41518a11cc387b669b2ee6586" +
"9f07e7be5551387a98ba977c732d080dcb0f29a048e3656912c6533e32ee7aed" +
"29b721769ce64e43d57133b074d839d531ed1f28510afb45ace10a1f4b794d6f"),
},
{
key: mustDecodeHex("5555555555555555555555555555555555555555555555555555555555555555"),
iv: mustDecodeHex("5555555555555555"),
output: mustDecodeHex("bea9411aa453c5434a5ae8c92862f564396855a9ea6e22d6d3b50ae1b3663311" +
"a4a3606c671d605ce16c3aece8e61ea145c59775017bee2fa6f88afc758069f7" +
"e0b8f676e644216f4d2a3422d7fa36c6c4931aca950e9da42788e6d0b6d1cd83" +
"8ef652e97b145b14871eae6c6804c7004db5ac2fce4c68c726d004b10fcaba86"),
},
{
key: mustDecodeHex("0000000000000000000000000000000000000000000000000000000000000000"),
iv: mustDecodeHex("000000000000000000000000"),
output: mustDecodeHex("76b8e0ada0f13d90405d6ae55386bd28bdd219b8a08ded1aa836efcc8b770dc7da41597c5157488d7724e03fb8d84a376a43b8f41518a11cc387b669b2ee6586"),
},
}
for _, c := range cases {
s := NewChaCha20Stream(c.key, c.iv)
input := make([]byte, len(c.output))
actualOutout := make([]byte, len(c.output))
s.XORKeyStream(actualOutout, input)
assert.Bytes(c.output).Equals(actualOutout)
}
}

@ -0,0 +1,85 @@
package internal
//go:generate go run chacha_core_gen.go
import (
"encoding/binary"
)
const (
wordSize = 4 // the size of ChaCha20's words
stateSize = 16 // the size of ChaCha20's state, in words
blockSize = stateSize * wordSize // the size of ChaCha20's block, in bytes
)
type ChaCha20Stream struct {
state [stateSize]uint32 // the state as an array of 16 32-bit words
block [blockSize]byte // the keystream as an array of 64 bytes
offset int // the offset of used bytes in block
rounds int
}
func NewChaCha20Stream(key []byte, nonce []byte, rounds int) *ChaCha20Stream {
s := new(ChaCha20Stream)
// the magic constants for 256-bit keys
s.state[0] = 0x61707865
s.state[1] = 0x3320646e
s.state[2] = 0x79622d32
s.state[3] = 0x6b206574
for i := 0; i < 8; i++ {
s.state[i+4] = binary.LittleEndian.Uint32(key[i*4 : i*4+4])
}
switch len(nonce) {
case 8:
s.state[14] = binary.LittleEndian.Uint32(nonce[0:])
s.state[15] = binary.LittleEndian.Uint32(nonce[4:])
case 12:
s.state[13] = binary.LittleEndian.Uint32(nonce[0:4])
s.state[14] = binary.LittleEndian.Uint32(nonce[4:8])
s.state[15] = binary.LittleEndian.Uint32(nonce[8:12])
default:
panic("bad nonce length")
}
s.rounds = rounds
s.advance()
return s
}
func (s *ChaCha20Stream) XORKeyStream(dst, src []byte) {
// Stride over the input in 64-byte blocks, minus the amount of keystream
// previously used. This will produce best results when processing blocks
// of a size evenly divisible by 64.
i := 0
max := len(src)
for i < max {
gap := blockSize - s.offset
limit := i + gap
if limit > max {
limit = max
}
o := s.offset
for j := i; j < limit; j++ {
dst[j] = src[j] ^ s.block[o]
o++
}
i += gap
s.offset = o
if o == blockSize {
s.advance()
}
}
}
func (s *ChaCha20Stream) advance() {
ChaCha20Block(&s.state, s.block[:], s.rounds)
s.offset = 0
s.state[12]++
}

@ -0,0 +1,126 @@
// GENERATED CODE. DO NOT MODIFY!
package internal
import "encoding/binary"
func ChaCha20Block(s *[16]uint32, out []byte, rounds int) {
var x0,x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12,x13,x14,x15 = s[0],s[1],s[2],s[3],s[4],s[5],s[6],s[7],s[8],s[9],s[10],s[11],s[12],s[13],s[14],s[15]
for i := 0; i < rounds; i+=2 {
var x uint32
x0+=x4
x=x12^x0
x12=(x << 16) | (x >> (32 - 16))
x8+=x12
x=x4^x8
x4=(x << 12) | (x >> (32 - 12))
x0+=x4
x=x12^x0
x12=(x << 8) | (x >> (32 - 8))
x8+=x12
x=x4^x8
x4=(x << 7) | (x >> (32 - 7))
x1+=x5
x=x13^x1
x13=(x << 16) | (x >> (32 - 16))
x9+=x13
x=x5^x9
x5=(x << 12) | (x >> (32 - 12))
x1+=x5
x=x13^x1
x13=(x << 8) | (x >> (32 - 8))
x9+=x13
x=x5^x9
x5=(x << 7) | (x >> (32 - 7))
x2+=x6
x=x14^x2
x14=(x << 16) | (x >> (32 - 16))
x10+=x14
x=x6^x10
x6=(x << 12) | (x >> (32 - 12))
x2+=x6
x=x14^x2
x14=(x << 8) | (x >> (32 - 8))
x10+=x14
x=x6^x10
x6=(x << 7) | (x >> (32 - 7))
x3+=x7
x=x15^x3
x15=(x << 16) | (x >> (32 - 16))
x11+=x15
x=x7^x11
x7=(x << 12) | (x >> (32 - 12))
x3+=x7
x=x15^x3
x15=(x << 8) | (x >> (32 - 8))
x11+=x15
x=x7^x11
x7=(x << 7) | (x >> (32 - 7))
x0+=x5
x=x15^x0
x15=(x << 16) | (x >> (32 - 16))
x10+=x15
x=x5^x10
x5=(x << 12) | (x >> (32 - 12))
x0+=x5
x=x15^x0
x15=(x << 8) | (x >> (32 - 8))
x10+=x15
x=x5^x10
x5=(x << 7) | (x >> (32 - 7))
x1+=x6
x=x12^x1
x12=(x << 16) | (x >> (32 - 16))
x11+=x12
x=x6^x11
x6=(x << 12) | (x >> (32 - 12))
x1+=x6
x=x12^x1
x12=(x << 8) | (x >> (32 - 8))
x11+=x12
x=x6^x11
x6=(x << 7) | (x >> (32 - 7))
x2+=x7
x=x13^x2
x13=(x << 16) | (x >> (32 - 16))
x8+=x13
x=x7^x8
x7=(x << 12) | (x >> (32 - 12))
x2+=x7
x=x13^x2
x13=(x << 8) | (x >> (32 - 8))
x8+=x13
x=x7^x8
x7=(x << 7) | (x >> (32 - 7))
x3+=x4
x=x14^x3
x14=(x << 16) | (x >> (32 - 16))
x9+=x14
x=x4^x9
x4=(x << 12) | (x >> (32 - 12))
x3+=x4
x=x14^x3
x14=(x << 8) | (x >> (32 - 8))
x9+=x14
x=x4^x9
x4=(x << 7) | (x >> (32 - 7))
}
binary.LittleEndian.PutUint32(out[0:4], s[0]+x0)
binary.LittleEndian.PutUint32(out[4:8], s[1]+x1)
binary.LittleEndian.PutUint32(out[8:12], s[2]+x2)
binary.LittleEndian.PutUint32(out[12:16], s[3]+x3)
binary.LittleEndian.PutUint32(out[16:20], s[4]+x4)
binary.LittleEndian.PutUint32(out[20:24], s[5]+x5)
binary.LittleEndian.PutUint32(out[24:28], s[6]+x6)
binary.LittleEndian.PutUint32(out[28:32], s[7]+x7)
binary.LittleEndian.PutUint32(out[32:36], s[8]+x8)
binary.LittleEndian.PutUint32(out[36:40], s[9]+x9)
binary.LittleEndian.PutUint32(out[40:44], s[10]+x10)
binary.LittleEndian.PutUint32(out[44:48], s[11]+x11)
binary.LittleEndian.PutUint32(out[48:52], s[12]+x12)
binary.LittleEndian.PutUint32(out[52:56], s[13]+x13)
binary.LittleEndian.PutUint32(out[56:60], s[14]+x14)
binary.LittleEndian.PutUint32(out[60:64], s[15]+x15)
}

@ -0,0 +1,70 @@
// +build generate
package main
import (
"fmt"
"log"
"os"
)
func writeQuarterRound(file *os.File, a, b, c, d int) {
add := "x%d+=x%d\n"
xor := "x=x%d^x%d\n"
rotate := "x%d=(x << %d) | (x >> (32 - %d))\n"
fmt.Fprintf(file, add, a, b)
fmt.Fprintf(file, xor, d, a)
fmt.Fprintf(file, rotate, d, 16, 16)
fmt.Fprintf(file, add, c, d)
fmt.Fprintf(file, xor, b, c)
fmt.Fprintf(file, rotate, b, 12, 12)
fmt.Fprintf(file, add, a, b)
fmt.Fprintf(file, xor, d, a)
fmt.Fprintf(file, rotate, d, 8, 8)
fmt.Fprintf(file, add, c, d)
fmt.Fprintf(file, xor, b, c)
fmt.Fprintf(file, rotate, b, 7, 7)
}
func writeChacha20Block(file *os.File) {
fmt.Fprintln(file, `
func ChaCha20Block(s *[16]uint32, out []byte, rounds int) {
var x0,x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12,x13,x14,x15 = s[0],s[1],s[2],s[3],s[4],s[5],s[6],s[7],s[8],s[9],s[10],s[11],s[12],s[13],s[14],s[15]
for i := 0; i < rounds; i+=2 {
var x uint32
`)
writeQuarterRound(file, 0, 4, 8, 12)
writeQuarterRound(file, 1, 5, 9, 13)
writeQuarterRound(file, 2, 6, 10, 14)
writeQuarterRound(file, 3, 7, 11, 15)
writeQuarterRound(file, 0, 5, 10, 15)
writeQuarterRound(file, 1, 6, 11, 12)
writeQuarterRound(file, 2, 7, 8, 13)
writeQuarterRound(file, 3, 4, 9, 14)
fmt.Fprintln(file, "}")
for i := 0; i < 16; i++ {
fmt.Fprintf(file, "binary.LittleEndian.PutUint32(out[%d:%d], s[%d]+x%d)\n", i*4, i*4+4, i, i)
}
fmt.Fprintln(file, "}")
fmt.Fprintln(file)
}
func main() {
file, err := os.OpenFile("chacha_core.go", os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0644)
if err != nil {
log.Fatalf("Failed to generate chacha_core.go: %v", err)
}
defer file.Close()
fmt.Fprintln(file, "// GENERATED CODE. DO NOT MODIFY!")
fmt.Fprintln(file, "package internal")
fmt.Fprintln(file)
fmt.Fprintln(file, "import \"encoding/binary\"")
fmt.Fprintln(file)
writeChacha20Block(file)
}
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