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cloudkeys-go/vendor/golang.org/x/crypto/scrypt/scrypt.go
Knut Ahlers a1df72edc5
Squashed commit of the following:
commit f0db1ff1f8
Author: Knut Ahlers <knut@ahlers.me>
Date:   Sun Dec 24 12:19:56 2017 +0100

    Mark option as deprecated

    Signed-off-by: Knut Ahlers <knut@ahlers.me>

commit 9891df2a16
Author: Knut Ahlers <knut@ahlers.me>
Date:   Sun Dec 24 12:11:56 2017 +0100

    Fix: Typo

    Signed-off-by: Knut Ahlers <knut@ahlers.me>

commit 836006de64
Author: Knut Ahlers <knut@ahlers.me>
Date:   Sun Dec 24 12:04:20 2017 +0100

    Add new dependencies

    Signed-off-by: Knut Ahlers <knut@ahlers.me>

commit d64fee60c8
Author: Knut Ahlers <knut@ahlers.me>
Date:   Sun Dec 24 11:55:52 2017 +0100

    Replace insecure password hashing

    Prior this commit passwords were hashed with a static salt and using the
    SHA1 hashing function. This could lead to passwords being attackable in
    case someone gets access to the raw data stored inside the database.
    This commit introduces password hashing using bcrypt hashing function
    which addresses this issue.

    Old passwords are not automatically re-hashed as they are unknown.
    Replacing the old password scheme is not that easy and needs #10 to be
    solved. Therefore the old hashing scheme is kept for compatibility
    reason.

    Signed-off-by: Knut Ahlers <knut@ahlers.me>

Signed-off-by: Knut Ahlers <knut@ahlers.me>

closes #14
closes #15
2017-12-24 19:44:24 +01:00

244 lines
5.8 KiB
Go

// 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 2017 are N=32768, r=8
// and p=1. The parameters N, r, and p should be increased as memory latency and
// CPU parallelism increases; consider setting N to the highest power of 2 you
// can derive within 100 milliseconds. 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
}