/usr/share/gocode/src/golang.org/x/crypto/pkcs12/internal/rc2/rc2.go is in golang-golang-x-crypto-dev 1:0.0~git20170629.0.5ef0053-2.
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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 | // Copyright 2015 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 rc2 implements the RC2 cipher
/*
https://www.ietf.org/rfc/rfc2268.txt
http://people.csail.mit.edu/rivest/pubs/KRRR98.pdf
This code is licensed under the MIT license.
*/
package rc2
import (
"crypto/cipher"
"encoding/binary"
)
// The rc2 block size in bytes
const BlockSize = 8
type rc2Cipher struct {
k [64]uint16
}
// New returns a new rc2 cipher with the given key and effective key length t1
func New(key []byte, t1 int) (cipher.Block, error) {
// TODO(dgryski): error checking for key length
return &rc2Cipher{
k: expandKey(key, t1),
}, nil
}
func (*rc2Cipher) BlockSize() int { return BlockSize }
var piTable = [256]byte{
0xd9, 0x78, 0xf9, 0xc4, 0x19, 0xdd, 0xb5, 0xed, 0x28, 0xe9, 0xfd, 0x79, 0x4a, 0xa0, 0xd8, 0x9d,
0xc6, 0x7e, 0x37, 0x83, 0x2b, 0x76, 0x53, 0x8e, 0x62, 0x4c, 0x64, 0x88, 0x44, 0x8b, 0xfb, 0xa2,
0x17, 0x9a, 0x59, 0xf5, 0x87, 0xb3, 0x4f, 0x13, 0x61, 0x45, 0x6d, 0x8d, 0x09, 0x81, 0x7d, 0x32,
0xbd, 0x8f, 0x40, 0xeb, 0x86, 0xb7, 0x7b, 0x0b, 0xf0, 0x95, 0x21, 0x22, 0x5c, 0x6b, 0x4e, 0x82,
0x54, 0xd6, 0x65, 0x93, 0xce, 0x60, 0xb2, 0x1c, 0x73, 0x56, 0xc0, 0x14, 0xa7, 0x8c, 0xf1, 0xdc,
0x12, 0x75, 0xca, 0x1f, 0x3b, 0xbe, 0xe4, 0xd1, 0x42, 0x3d, 0xd4, 0x30, 0xa3, 0x3c, 0xb6, 0x26,
0x6f, 0xbf, 0x0e, 0xda, 0x46, 0x69, 0x07, 0x57, 0x27, 0xf2, 0x1d, 0x9b, 0xbc, 0x94, 0x43, 0x03,
0xf8, 0x11, 0xc7, 0xf6, 0x90, 0xef, 0x3e, 0xe7, 0x06, 0xc3, 0xd5, 0x2f, 0xc8, 0x66, 0x1e, 0xd7,
0x08, 0xe8, 0xea, 0xde, 0x80, 0x52, 0xee, 0xf7, 0x84, 0xaa, 0x72, 0xac, 0x35, 0x4d, 0x6a, 0x2a,
0x96, 0x1a, 0xd2, 0x71, 0x5a, 0x15, 0x49, 0x74, 0x4b, 0x9f, 0xd0, 0x5e, 0x04, 0x18, 0xa4, 0xec,
0xc2, 0xe0, 0x41, 0x6e, 0x0f, 0x51, 0xcb, 0xcc, 0x24, 0x91, 0xaf, 0x50, 0xa1, 0xf4, 0x70, 0x39,
0x99, 0x7c, 0x3a, 0x85, 0x23, 0xb8, 0xb4, 0x7a, 0xfc, 0x02, 0x36, 0x5b, 0x25, 0x55, 0x97, 0x31,
0x2d, 0x5d, 0xfa, 0x98, 0xe3, 0x8a, 0x92, 0xae, 0x05, 0xdf, 0x29, 0x10, 0x67, 0x6c, 0xba, 0xc9,
0xd3, 0x00, 0xe6, 0xcf, 0xe1, 0x9e, 0xa8, 0x2c, 0x63, 0x16, 0x01, 0x3f, 0x58, 0xe2, 0x89, 0xa9,
0x0d, 0x38, 0x34, 0x1b, 0xab, 0x33, 0xff, 0xb0, 0xbb, 0x48, 0x0c, 0x5f, 0xb9, 0xb1, 0xcd, 0x2e,
0xc5, 0xf3, 0xdb, 0x47, 0xe5, 0xa5, 0x9c, 0x77, 0x0a, 0xa6, 0x20, 0x68, 0xfe, 0x7f, 0xc1, 0xad,
}
func expandKey(key []byte, t1 int) [64]uint16 {
l := make([]byte, 128)
copy(l, key)
var t = len(key)
var t8 = (t1 + 7) / 8
var tm = byte(255 % uint(1<<(8+uint(t1)-8*uint(t8))))
for i := len(key); i < 128; i++ {
l[i] = piTable[l[i-1]+l[uint8(i-t)]]
}
l[128-t8] = piTable[l[128-t8]&tm]
for i := 127 - t8; i >= 0; i-- {
l[i] = piTable[l[i+1]^l[i+t8]]
}
var k [64]uint16
for i := range k {
k[i] = uint16(l[2*i]) + uint16(l[2*i+1])*256
}
return k
}
func rotl16(x uint16, b uint) uint16 {
return (x >> (16 - b)) | (x << b)
}
func (c *rc2Cipher) Encrypt(dst, src []byte) {
r0 := binary.LittleEndian.Uint16(src[0:])
r1 := binary.LittleEndian.Uint16(src[2:])
r2 := binary.LittleEndian.Uint16(src[4:])
r3 := binary.LittleEndian.Uint16(src[6:])
var j int
for j <= 16 {
// mix r0
r0 = r0 + c.k[j] + (r3 & r2) + ((^r3) & r1)
r0 = rotl16(r0, 1)
j++
// mix r1
r1 = r1 + c.k[j] + (r0 & r3) + ((^r0) & r2)
r1 = rotl16(r1, 2)
j++
// mix r2
r2 = r2 + c.k[j] + (r1 & r0) + ((^r1) & r3)
r2 = rotl16(r2, 3)
j++
// mix r3
r3 = r3 + c.k[j] + (r2 & r1) + ((^r2) & r0)
r3 = rotl16(r3, 5)
j++
}
r0 = r0 + c.k[r3&63]
r1 = r1 + c.k[r0&63]
r2 = r2 + c.k[r1&63]
r3 = r3 + c.k[r2&63]
for j <= 40 {
// mix r0
r0 = r0 + c.k[j] + (r3 & r2) + ((^r3) & r1)
r0 = rotl16(r0, 1)
j++
// mix r1
r1 = r1 + c.k[j] + (r0 & r3) + ((^r0) & r2)
r1 = rotl16(r1, 2)
j++
// mix r2
r2 = r2 + c.k[j] + (r1 & r0) + ((^r1) & r3)
r2 = rotl16(r2, 3)
j++
// mix r3
r3 = r3 + c.k[j] + (r2 & r1) + ((^r2) & r0)
r3 = rotl16(r3, 5)
j++
}
r0 = r0 + c.k[r3&63]
r1 = r1 + c.k[r0&63]
r2 = r2 + c.k[r1&63]
r3 = r3 + c.k[r2&63]
for j <= 60 {
// mix r0
r0 = r0 + c.k[j] + (r3 & r2) + ((^r3) & r1)
r0 = rotl16(r0, 1)
j++
// mix r1
r1 = r1 + c.k[j] + (r0 & r3) + ((^r0) & r2)
r1 = rotl16(r1, 2)
j++
// mix r2
r2 = r2 + c.k[j] + (r1 & r0) + ((^r1) & r3)
r2 = rotl16(r2, 3)
j++
// mix r3
r3 = r3 + c.k[j] + (r2 & r1) + ((^r2) & r0)
r3 = rotl16(r3, 5)
j++
}
binary.LittleEndian.PutUint16(dst[0:], r0)
binary.LittleEndian.PutUint16(dst[2:], r1)
binary.LittleEndian.PutUint16(dst[4:], r2)
binary.LittleEndian.PutUint16(dst[6:], r3)
}
func (c *rc2Cipher) Decrypt(dst, src []byte) {
r0 := binary.LittleEndian.Uint16(src[0:])
r1 := binary.LittleEndian.Uint16(src[2:])
r2 := binary.LittleEndian.Uint16(src[4:])
r3 := binary.LittleEndian.Uint16(src[6:])
j := 63
for j >= 44 {
// unmix r3
r3 = rotl16(r3, 16-5)
r3 = r3 - c.k[j] - (r2 & r1) - ((^r2) & r0)
j--
// unmix r2
r2 = rotl16(r2, 16-3)
r2 = r2 - c.k[j] - (r1 & r0) - ((^r1) & r3)
j--
// unmix r1
r1 = rotl16(r1, 16-2)
r1 = r1 - c.k[j] - (r0 & r3) - ((^r0) & r2)
j--
// unmix r0
r0 = rotl16(r0, 16-1)
r0 = r0 - c.k[j] - (r3 & r2) - ((^r3) & r1)
j--
}
r3 = r3 - c.k[r2&63]
r2 = r2 - c.k[r1&63]
r1 = r1 - c.k[r0&63]
r0 = r0 - c.k[r3&63]
for j >= 20 {
// unmix r3
r3 = rotl16(r3, 16-5)
r3 = r3 - c.k[j] - (r2 & r1) - ((^r2) & r0)
j--
// unmix r2
r2 = rotl16(r2, 16-3)
r2 = r2 - c.k[j] - (r1 & r0) - ((^r1) & r3)
j--
// unmix r1
r1 = rotl16(r1, 16-2)
r1 = r1 - c.k[j] - (r0 & r3) - ((^r0) & r2)
j--
// unmix r0
r0 = rotl16(r0, 16-1)
r0 = r0 - c.k[j] - (r3 & r2) - ((^r3) & r1)
j--
}
r3 = r3 - c.k[r2&63]
r2 = r2 - c.k[r1&63]
r1 = r1 - c.k[r0&63]
r0 = r0 - c.k[r3&63]
for j >= 0 {
// unmix r3
r3 = rotl16(r3, 16-5)
r3 = r3 - c.k[j] - (r2 & r1) - ((^r2) & r0)
j--
// unmix r2
r2 = rotl16(r2, 16-3)
r2 = r2 - c.k[j] - (r1 & r0) - ((^r1) & r3)
j--
// unmix r1
r1 = rotl16(r1, 16-2)
r1 = r1 - c.k[j] - (r0 & r3) - ((^r0) & r2)
j--
// unmix r0
r0 = rotl16(r0, 16-1)
r0 = r0 - c.k[j] - (r3 & r2) - ((^r3) & r1)
j--
}
binary.LittleEndian.PutUint16(dst[0:], r0)
binary.LittleEndian.PutUint16(dst[2:], r1)
binary.LittleEndian.PutUint16(dst[4:], r2)
binary.LittleEndian.PutUint16(dst[6:], r3)
}
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