/usr/share/gocode/src/golang.org/x/crypto/scrypt/scrypt.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 | // Copyright 2012 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 scrypt implements the scrypt key derivation function as defined in
// Colin Percival's paper "Stronger Key Derivation via Sequential Memory-Hard
// Functions" (https://www.tarsnap.com/scrypt/scrypt.pdf).
package scrypt // import "golang.org/x/crypto/scrypt"
import (
"crypto/sha256"
"errors"
"golang.org/x/crypto/pbkdf2"
)
const maxInt = int(^uint(0) >> 1)
// blockCopy copies n numbers from src into dst.
func blockCopy(dst, src []uint32, n int) {
copy(dst, src[:n])
}
// blockXOR XORs numbers from dst with n numbers from src.
func blockXOR(dst, src []uint32, n int) {
for i, v := range src[:n] {
dst[i] ^= v
}
}
// salsaXOR applies Salsa20/8 to the XOR of 16 numbers from tmp and in,
// and puts the result into both both tmp and out.
func salsaXOR(tmp *[16]uint32, in, out []uint32) {
w0 := tmp[0] ^ in[0]
w1 := tmp[1] ^ in[1]
w2 := tmp[2] ^ in[2]
w3 := tmp[3] ^ in[3]
w4 := tmp[4] ^ in[4]
w5 := tmp[5] ^ in[5]
w6 := tmp[6] ^ in[6]
w7 := tmp[7] ^ in[7]
w8 := tmp[8] ^ in[8]
w9 := tmp[9] ^ in[9]
w10 := tmp[10] ^ in[10]
w11 := tmp[11] ^ in[11]
w12 := tmp[12] ^ in[12]
w13 := tmp[13] ^ in[13]
w14 := tmp[14] ^ in[14]
w15 := tmp[15] ^ in[15]
x0, x1, x2, x3, x4, x5, x6, x7, x8 := w0, w1, w2, w3, w4, w5, w6, w7, w8
x9, x10, x11, x12, x13, x14, x15 := w9, w10, w11, w12, w13, w14, w15
for i := 0; i < 8; i += 2 {
u := x0 + x12
x4 ^= u<<7 | u>>(32-7)
u = x4 + x0
x8 ^= u<<9 | u>>(32-9)
u = x8 + x4
x12 ^= u<<13 | u>>(32-13)
u = x12 + x8
x0 ^= u<<18 | u>>(32-18)
u = x5 + x1
x9 ^= u<<7 | u>>(32-7)
u = x9 + x5
x13 ^= u<<9 | u>>(32-9)
u = x13 + x9
x1 ^= u<<13 | u>>(32-13)
u = x1 + x13
x5 ^= u<<18 | u>>(32-18)
u = x10 + x6
x14 ^= u<<7 | u>>(32-7)
u = x14 + x10
x2 ^= u<<9 | u>>(32-9)
u = x2 + x14
x6 ^= u<<13 | u>>(32-13)
u = x6 + x2
x10 ^= u<<18 | u>>(32-18)
u = x15 + x11
x3 ^= u<<7 | u>>(32-7)
u = x3 + x15
x7 ^= u<<9 | u>>(32-9)
u = x7 + x3
x11 ^= u<<13 | u>>(32-13)
u = x11 + x7
x15 ^= u<<18 | u>>(32-18)
u = x0 + x3
x1 ^= u<<7 | u>>(32-7)
u = x1 + x0
x2 ^= u<<9 | u>>(32-9)
u = x2 + x1
x3 ^= u<<13 | u>>(32-13)
u = x3 + x2
x0 ^= u<<18 | u>>(32-18)
u = x5 + x4
x6 ^= u<<7 | u>>(32-7)
u = x6 + x5
x7 ^= u<<9 | u>>(32-9)
u = x7 + x6
x4 ^= u<<13 | u>>(32-13)
u = x4 + x7
x5 ^= u<<18 | u>>(32-18)
u = x10 + x9
x11 ^= u<<7 | u>>(32-7)
u = x11 + x10
x8 ^= u<<9 | u>>(32-9)
u = x8 + x11
x9 ^= u<<13 | u>>(32-13)
u = x9 + x8
x10 ^= u<<18 | u>>(32-18)
u = x15 + x14
x12 ^= u<<7 | u>>(32-7)
u = x12 + x15
x13 ^= u<<9 | u>>(32-9)
u = x13 + x12
x14 ^= u<<13 | u>>(32-13)
u = x14 + x13
x15 ^= u<<18 | u>>(32-18)
}
x0 += w0
x1 += w1
x2 += w2
x3 += w3
x4 += w4
x5 += w5
x6 += w6
x7 += w7
x8 += w8
x9 += w9
x10 += w10
x11 += w11
x12 += w12
x13 += w13
x14 += w14
x15 += w15
out[0], tmp[0] = x0, x0
out[1], tmp[1] = x1, x1
out[2], tmp[2] = x2, x2
out[3], tmp[3] = x3, x3
out[4], tmp[4] = x4, x4
out[5], tmp[5] = x5, x5
out[6], tmp[6] = x6, x6
out[7], tmp[7] = x7, x7
out[8], tmp[8] = x8, x8
out[9], tmp[9] = x9, x9
out[10], tmp[10] = x10, x10
out[11], tmp[11] = x11, x11
out[12], tmp[12] = x12, x12
out[13], tmp[13] = x13, x13
out[14], tmp[14] = x14, x14
out[15], tmp[15] = x15, x15
}
func blockMix(tmp *[16]uint32, in, out []uint32, r int) {
blockCopy(tmp[:], in[(2*r-1)*16:], 16)
for i := 0; i < 2*r; i += 2 {
salsaXOR(tmp, in[i*16:], out[i*8:])
salsaXOR(tmp, in[i*16+16:], out[i*8+r*16:])
}
}
func integer(b []uint32, r int) uint64 {
j := (2*r - 1) * 16
return uint64(b[j]) | uint64(b[j+1])<<32
}
func smix(b []byte, r, N int, v, xy []uint32) {
var tmp [16]uint32
x := xy
y := xy[32*r:]
j := 0
for i := 0; i < 32*r; i++ {
x[i] = uint32(b[j]) | uint32(b[j+1])<<8 | uint32(b[j+2])<<16 | uint32(b[j+3])<<24
j += 4
}
for i := 0; i < N; i += 2 {
blockCopy(v[i*(32*r):], x, 32*r)
blockMix(&tmp, x, y, r)
blockCopy(v[(i+1)*(32*r):], y, 32*r)
blockMix(&tmp, y, x, r)
}
for i := 0; i < N; i += 2 {
j := int(integer(x, r) & uint64(N-1))
blockXOR(x, v[j*(32*r):], 32*r)
blockMix(&tmp, x, y, r)
j = int(integer(y, r) & uint64(N-1))
blockXOR(y, v[j*(32*r):], 32*r)
blockMix(&tmp, y, x, r)
}
j = 0
for _, v := range x[:32*r] {
b[j+0] = byte(v >> 0)
b[j+1] = byte(v >> 8)
b[j+2] = byte(v >> 16)
b[j+3] = byte(v >> 24)
j += 4
}
}
// Key derives a key from the password, salt, and cost parameters, returning
// a byte slice of length keyLen that can be used as cryptographic key.
//
// N is a CPU/memory cost parameter, which must be a power of two greater than 1.
// r and p must satisfy r * p < 2³⁰. If the parameters do not satisfy the
// limits, the function returns a nil byte slice and an error.
//
// For example, you can get a derived key for e.g. AES-256 (which needs a
// 32-byte key) by doing:
//
// dk, err := scrypt.Key([]byte("some password"), salt, 16384, 8, 1, 32)
//
// The recommended parameters for interactive logins as of 2009 are N=16384,
// r=8, p=1. They should be increased as memory latency and CPU parallelism
// increases. Remember to get a good random salt.
func Key(password, salt []byte, N, r, p, keyLen int) ([]byte, error) {
if N <= 1 || N&(N-1) != 0 {
return nil, errors.New("scrypt: N must be > 1 and a power of 2")
}
if uint64(r)*uint64(p) >= 1<<30 || r > maxInt/128/p || r > maxInt/256 || N > maxInt/128/r {
return nil, errors.New("scrypt: parameters are too large")
}
xy := make([]uint32, 64*r)
v := make([]uint32, 32*N*r)
b := pbkdf2.Key(password, salt, 1, p*128*r, sha256.New)
for i := 0; i < p; i++ {
smix(b[i*128*r:], r, N, v, xy)
}
return pbkdf2.Key(password, b, 1, keyLen, sha256.New), nil
}
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