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Diffstat (limited to 'vendor/golang.org/x/crypto/scrypt/scrypt.go')
-rw-r--r-- | vendor/golang.org/x/crypto/scrypt/scrypt.go | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/scrypt/scrypt.go b/vendor/golang.org/x/crypto/scrypt/scrypt.go new file mode 100644 index 000000000..7455395cf --- /dev/null +++ b/vendor/golang.org/x/crypto/scrypt/scrypt.go @@ -0,0 +1,243 @@ +// 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" (http://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 +} |