File: crypt.go

package info (click to toggle)
golang-github-audriusbutkevicius-kcp-go 20160629%2Bgit20171025.8ae5f52-6
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 268 kB
  • sloc: makefile: 2
file content (288 lines) | stat: -rw-r--r-- 8,010 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
package kcp

import (
	"crypto/aes"
	"crypto/cipher"
	"crypto/des"
	"crypto/sha1"

	"github.com/templexxx/xor"
	"github.com/tjfoc/gmsm/sm4"

	"golang.org/x/crypto/blowfish"
	"golang.org/x/crypto/cast5"
	"golang.org/x/crypto/pbkdf2"
	"golang.org/x/crypto/salsa20"
	"golang.org/x/crypto/tea"
	"golang.org/x/crypto/twofish"
	"golang.org/x/crypto/xtea"
)

var (
	initialVector = []byte{167, 115, 79, 156, 18, 172, 27, 1, 164, 21, 242, 193, 252, 120, 230, 107}
	saltxor       = `sH3CIVoF#rWLtJo6`
)

// BlockCrypt defines encryption/decryption methods for a given byte slice.
// Notes on implementing: the data to be encrypted contains a builtin
// nonce at the first 16 bytes
type BlockCrypt interface {
	// Encrypt encrypts the whole block in src into dst.
	// Dst and src may point at the same memory.
	Encrypt(dst, src []byte)

	// Decrypt decrypts the whole block in src into dst.
	// Dst and src may point at the same memory.
	Decrypt(dst, src []byte)
}

type salsa20BlockCrypt struct {
	key [32]byte
}

// NewSalsa20BlockCrypt https://en.wikipedia.org/wiki/Salsa20
func NewSalsa20BlockCrypt(key []byte) (BlockCrypt, error) {
	c := new(salsa20BlockCrypt)
	copy(c.key[:], key)
	return c, nil
}

func (c *salsa20BlockCrypt) Encrypt(dst, src []byte) {
	salsa20.XORKeyStream(dst[8:], src[8:], src[:8], &c.key)
	copy(dst[:8], src[:8])
}
func (c *salsa20BlockCrypt) Decrypt(dst, src []byte) {
	salsa20.XORKeyStream(dst[8:], src[8:], src[:8], &c.key)
	copy(dst[:8], src[:8])
}

type sm4BlockCrypt struct {
	encbuf []byte
	decbuf []byte
	block  cipher.Block
}

// NewSM4BlockCrypt https://github.com/tjfoc/gmsm/tree/master/sm4
func NewSM4BlockCrypt(key []byte) (BlockCrypt, error) {
	c := new(sm4BlockCrypt)
	block, err := sm4.NewCipher(key)
	if err != nil {
		return nil, err
	}
	c.block = block
	c.encbuf = make([]byte, sm4.BlockSize)
	c.decbuf = make([]byte, 2*sm4.BlockSize)
	return c, nil
}

func (c *sm4BlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
func (c *sm4BlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }

type twofishBlockCrypt struct {
	encbuf []byte
	decbuf []byte
	block  cipher.Block
}

// NewTwofishBlockCrypt https://en.wikipedia.org/wiki/Twofish
func NewTwofishBlockCrypt(key []byte) (BlockCrypt, error) {
	c := new(twofishBlockCrypt)
	block, err := twofish.NewCipher(key)
	if err != nil {
		return nil, err
	}
	c.block = block
	c.encbuf = make([]byte, twofish.BlockSize)
	c.decbuf = make([]byte, 2*twofish.BlockSize)
	return c, nil
}

func (c *twofishBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
func (c *twofishBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }

type tripleDESBlockCrypt struct {
	encbuf []byte
	decbuf []byte
	block  cipher.Block
}

// NewTripleDESBlockCrypt https://en.wikipedia.org/wiki/Triple_DES
func NewTripleDESBlockCrypt(key []byte) (BlockCrypt, error) {
	c := new(tripleDESBlockCrypt)
	block, err := des.NewTripleDESCipher(key)
	if err != nil {
		return nil, err
	}
	c.block = block
	c.encbuf = make([]byte, des.BlockSize)
	c.decbuf = make([]byte, 2*des.BlockSize)
	return c, nil
}

func (c *tripleDESBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
func (c *tripleDESBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }

type cast5BlockCrypt struct {
	encbuf []byte
	decbuf []byte
	block  cipher.Block
}

// NewCast5BlockCrypt https://en.wikipedia.org/wiki/CAST-128
func NewCast5BlockCrypt(key []byte) (BlockCrypt, error) {
	c := new(cast5BlockCrypt)
	block, err := cast5.NewCipher(key)
	if err != nil {
		return nil, err
	}
	c.block = block
	c.encbuf = make([]byte, cast5.BlockSize)
	c.decbuf = make([]byte, 2*cast5.BlockSize)
	return c, nil
}

func (c *cast5BlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
func (c *cast5BlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }

type blowfishBlockCrypt struct {
	encbuf []byte
	decbuf []byte
	block  cipher.Block
}

// NewBlowfishBlockCrypt https://en.wikipedia.org/wiki/Blowfish_(cipher)
func NewBlowfishBlockCrypt(key []byte) (BlockCrypt, error) {
	c := new(blowfishBlockCrypt)
	block, err := blowfish.NewCipher(key)
	if err != nil {
		return nil, err
	}
	c.block = block
	c.encbuf = make([]byte, blowfish.BlockSize)
	c.decbuf = make([]byte, 2*blowfish.BlockSize)
	return c, nil
}

func (c *blowfishBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
func (c *blowfishBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }

type aesBlockCrypt struct {
	encbuf []byte
	decbuf []byte
	block  cipher.Block
}

// NewAESBlockCrypt https://en.wikipedia.org/wiki/Advanced_Encryption_Standard
func NewAESBlockCrypt(key []byte) (BlockCrypt, error) {
	c := new(aesBlockCrypt)
	block, err := aes.NewCipher(key)
	if err != nil {
		return nil, err
	}
	c.block = block
	c.encbuf = make([]byte, aes.BlockSize)
	c.decbuf = make([]byte, 2*aes.BlockSize)
	return c, nil
}

func (c *aesBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
func (c *aesBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }

type teaBlockCrypt struct {
	encbuf []byte
	decbuf []byte
	block  cipher.Block
}

// NewTEABlockCrypt https://en.wikipedia.org/wiki/Tiny_Encryption_Algorithm
func NewTEABlockCrypt(key []byte) (BlockCrypt, error) {
	c := new(teaBlockCrypt)
	block, err := tea.NewCipherWithRounds(key, 16)
	if err != nil {
		return nil, err
	}
	c.block = block
	c.encbuf = make([]byte, tea.BlockSize)
	c.decbuf = make([]byte, 2*tea.BlockSize)
	return c, nil
}

func (c *teaBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
func (c *teaBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }

type xteaBlockCrypt struct {
	encbuf []byte
	decbuf []byte
	block  cipher.Block
}

// NewXTEABlockCrypt https://en.wikipedia.org/wiki/XTEA
func NewXTEABlockCrypt(key []byte) (BlockCrypt, error) {
	c := new(xteaBlockCrypt)
	block, err := xtea.NewCipher(key)
	if err != nil {
		return nil, err
	}
	c.block = block
	c.encbuf = make([]byte, xtea.BlockSize)
	c.decbuf = make([]byte, 2*xtea.BlockSize)
	return c, nil
}

func (c *xteaBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
func (c *xteaBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }

type simpleXORBlockCrypt struct {
	xortbl []byte
}

// NewSimpleXORBlockCrypt simple xor with key expanding
func NewSimpleXORBlockCrypt(key []byte) (BlockCrypt, error) {
	c := new(simpleXORBlockCrypt)
	c.xortbl = pbkdf2.Key(key, []byte(saltxor), 32, mtuLimit, sha1.New)
	return c, nil
}

func (c *simpleXORBlockCrypt) Encrypt(dst, src []byte) { xor.Bytes(dst, src, c.xortbl) }
func (c *simpleXORBlockCrypt) Decrypt(dst, src []byte) { xor.Bytes(dst, src, c.xortbl) }

type noneBlockCrypt struct{}

// NewNoneBlockCrypt does nothing but copying
func NewNoneBlockCrypt(key []byte) (BlockCrypt, error) {
	return new(noneBlockCrypt), nil
}

func (c *noneBlockCrypt) Encrypt(dst, src []byte) { copy(dst, src) }
func (c *noneBlockCrypt) Decrypt(dst, src []byte) { copy(dst, src) }

// packet encryption with local CFB mode
func encrypt(block cipher.Block, dst, src, buf []byte) {
	blocksize := block.BlockSize()
	tbl := buf[:blocksize]
	block.Encrypt(tbl, initialVector)
	n := len(src) / blocksize
	base := 0
	for i := 0; i < n; i++ {
		xor.BytesSrc1(dst[base:], src[base:], tbl)
		block.Encrypt(tbl, dst[base:])
		base += blocksize
	}
	xor.BytesSrc0(dst[base:], src[base:], tbl)
}

func decrypt(block cipher.Block, dst, src, buf []byte) {
	blocksize := block.BlockSize()
	tbl := buf[:blocksize]
	next := buf[blocksize:]
	block.Encrypt(tbl, initialVector)
	n := len(src) / blocksize
	base := 0
	for i := 0; i < n; i++ {
		block.Encrypt(next, src[base:])
		xor.BytesSrc1(dst[base:], src[base:], tbl)
		tbl, next = next, tbl
		base += blocksize
	}
	xor.BytesSrc0(dst[base:], src[base:], tbl)
}