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Diffstat (limited to 'src/scrypt.go')
-rw-r--r--src/scrypt.go357
1 files changed, 55 insertions, 302 deletions
diff --git a/src/scrypt.go b/src/scrypt.go
index fe6cb8d..a4f03d2 100644
--- a/src/scrypt.go
+++ b/src/scrypt.go
@@ -1,28 +1,30 @@
package scrypt
import (
- "crypto/hmac"
"crypto/rand"
- "crypto/sha256"
- "encoding/binary"
"encoding/hex"
"errors"
"fmt"
- "hash"
"io"
- "math/bits"
"os"
"slices"
)
+/*
+#define _XOPEN_SOURCE 700
+#include <stdlib.h>
+#include <scrypt-kdf.h>
+*/
+import "C"
+
+
+
const (
- saltMinLength = 32
- desiredLength = 32
- maxInt = int((^uint(0)) >> 1)
MinimumPasswordLength = 16
-
+ _SALT_MIN_LENGTH = 32
+ _DESIRED_LENGTH = 32
_N = 1 << 15
r = 8
p = 1
@@ -30,274 +32,12 @@ const (
var (
- ErrBadN = errors.New("scrypt: N must be > 1 and a power of 2")
- ErrParamsTooLarge = errors.New("scrypt: parameters are too large")
- ErrSaltTooSmall = errors.New("scrypt: salt is too small")
+ ErrSaltTooSmall = errors.New("scrypt: salt is too small")
+ ErrInternal = errors.New("scrypt: internal error")
)
-// Package pbkdf2 implements the key derivation function PBKDF2 as defined in
-// RFC 2898 / PKCS #5 v2.0.
-//
-// A key derivation function is useful when encrypting data based on a password
-// or any other not-fully-random data. It uses a pseudorandom function to derive
-// a secure encryption key based on the password.
-//
-// While v2.0 of the standard defines only one pseudorandom function to use,
-// HMAC-SHA1, the drafted v2.1 specification allows use of all five FIPS
-// Approved Hash Functions SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512 for
-// HMAC. To choose, you can pass the `New` functions from the different SHA
-// packages to pbkdf2.Key.
-//
-//
-// Key derives a key from the password, salt and iteration count, returning a
-// []byte of length keylen that can be used as cryptographic key. The key is
-// derived based on the method described as PBKDF2 with the HMAC variant using
-// the supplied hash function.
-//
-// For example, to use a HMAC-SHA-1 based PBKDF2 key derivation function, you
-// can get a derived key for e.g. AES-256 (which needs a 32-byte key) by
-// doing:
-//
-// dk := pbkdf2.Key([]byte("some password"), salt, 4096, 32, sha1.New)
-//
-// Remember to get a good random salt. At least 8 bytes is recommended by the
-// RFC.
-//
-// Using a higher iteration count will increase the cost of an exhaustive
-// search but will also make derivation proportionally slower.
-func _PBKDF2Key(
- password []byte,
- salt []byte,
- iter int,
- keyLen int,
- h func() hash.Hash,
-) []byte {
- prf := hmac.New(h, password)
- hashLen := prf.Size()
- numBlocks := (keyLen + hashLen - 1) / hashLen
-
- var buffer [4]byte
- dk := make([]byte, 0, numBlocks*hashLen)
- U := make([]byte, hashLen)
- for block := 1; block <= numBlocks; block++ {
- // N.B.: || means concatenation, ^ means XOR
- // for each block T_i = U_1 ^ U_2 ^ ... ^ U_iter
- // U_1 = PRF(password, salt || uint(i))
- prf.Reset()
- prf.Write(salt)
- buffer[0] = byte(block >> 24)
- buffer[1] = byte(block >> 16)
- buffer[2] = byte(block >> 8)
- buffer[3] = byte(block >> 0)
- prf.Write(buffer[:4])
- dk = prf.Sum(dk)
- T := dk[len(dk) - hashLen:]
- copy(U, T)
-
- // U_n = PRF(password, U_(n - 1))
- for n := 2; n <= iter; n++ {
- prf.Reset()
- prf.Write(U)
- U = U[:0]
- U = prf.Sum(U)
- for x := range U {
- T[x] ^= U[x]
- }
- }
- }
- return dk[:keyLen]
-}
-
-// blockCopy copies n numbers from src into dst.
-func blockCopy(dst []uint32, src []uint32, n int) {
- copy(dst, src[:n])
-}
-
-// blockXOR XORs numbers from dst with n numbers from src.
-func blockXOR(dst []uint32, 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 tmp and out.
-func salsaXOR(tmp *[16]uint32, in []uint32, 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 := 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
-
- for i := 0; i < 8; i += 2 {
- x4 ^= bits.RotateLeft32(x0 + x12, 7)
- x8 ^= bits.RotateLeft32(x4 + x0, 9)
- x12 ^= bits.RotateLeft32(x8 + x4, 13)
- x0 ^= bits.RotateLeft32(x12 + x8, 18)
-
- x9 ^= bits.RotateLeft32(x5 + x1, 7)
- x13 ^= bits.RotateLeft32(x9 + x5, 9)
- x1 ^= bits.RotateLeft32(x13 + x9, 13)
- x5 ^= bits.RotateLeft32(x1 + x13, 18)
-
- x14 ^= bits.RotateLeft32(x10 + x6, 7)
- x2 ^= bits.RotateLeft32(x14 + x10, 9)
- x6 ^= bits.RotateLeft32(x2 + x14, 13)
- x10 ^= bits.RotateLeft32(x6 + x2, 18)
-
- x3 ^= bits.RotateLeft32(x15 + x11, 7)
- x7 ^= bits.RotateLeft32(x3 + x15, 9)
- x11 ^= bits.RotateLeft32(x7 + x3, 13)
- x15 ^= bits.RotateLeft32(x11 + x7, 18)
-
- x1 ^= bits.RotateLeft32(x0 + x3, 7)
- x2 ^= bits.RotateLeft32(x1 + x0, 9)
- x3 ^= bits.RotateLeft32(x2 + x1, 13)
- x0 ^= bits.RotateLeft32(x3 + x2, 18)
-
- x6 ^= bits.RotateLeft32(x5 + x4, 7)
- x7 ^= bits.RotateLeft32(x6 + x5, 9)
- x4 ^= bits.RotateLeft32(x7 + x6, 13)
- x5 ^= bits.RotateLeft32(x4 + x7, 18)
-
- x11 ^= bits.RotateLeft32(x10 + x9, 7)
- x8 ^= bits.RotateLeft32(x11 + x10, 9)
- x9 ^= bits.RotateLeft32(x8 + x11, 13)
- x10 ^= bits.RotateLeft32(x9 + x8, 18)
-
- x12 ^= bits.RotateLeft32(x15 + x14, 7)
- x13 ^= bits.RotateLeft32(x12 + x15, 9)
- x14 ^= bits.RotateLeft32(x13 + x12, 13)
- x15 ^= bits.RotateLeft32(x14 + x13, 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 []uint32, 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 int, N int, v []uint32, xy []uint32) {
- var tmp [16]uint32
- R := 32 * r
- x := xy
- y := xy[R:]
-
- j := 0
- for i := 0; i < R; i++ {
- x[i] = binary.LittleEndian.Uint32(b[j:])
- j += 4
- }
- for i := 0; i < N; i += 2 {
- blockCopy(v[i * R:], x, R)
- blockMix(&tmp, x, y, r)
-
- blockCopy(v[(i + 1) * R:], y, 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 * R:], R)
- blockMix(&tmp, x, y, r)
-
- j = int(integer(y, r) & uint64(N - 1))
- blockXOR(y, v[j * R:], R)
- blockMix(&tmp, y, x, r)
- }
- j = 0
- for _, v := range x[:R] {
- binary.LittleEndian.PutUint32(b[j:], v)
- j += 4
- }
-}
-
-func validateParams(N int, r int, p int) error {
- if N <= 1 || N & (N - 1) != 0 {
- return ErrBadN
- }
-
- if ((uint64(r) * uint64(p)) >= (1 << 30)) ||
- r > maxInt / 128 / p ||
- r > maxInt / 256 ||
- N > maxInt / 128 / r {
- return ErrParamsTooLarge
- }
-
- return nil
-}
-
// 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).
@@ -325,39 +65,37 @@ func scrypt(
N int,
r int,
p int,
- keyLen int,
+ outlen int,
) ([]byte, error) {
- err := validateParams(N, r, p)
- if err != nil {
- return nil, err
- }
-
- xy := make([]uint32, 64 * r)
- v := make([]uint32, 32 * r * N)
- b := _PBKDF2Key(password, salt, 1, p * 128 * r, sha256.New)
-
- for i := 0; i < p; i++ {
- smix(b[i * 128 * r:], r, N, v, xy)
- }
-
- return _PBKDF2Key(password, b, 1, keyLen, sha256.New), nil
-}
-
-func SaltFrom(r io.Reader) ([]byte, error) {
- buffer := make([]byte, saltMinLength)
- _, err := io.ReadFull(r, buffer)
- if err != nil {
- return nil, err
+ passwordbuf := C.CBytes(password)
+ saltbuf := C.CBytes(salt)
+ defer C.free(passwordbuf)
+ defer C.free(saltbuf)
+
+ outbuf := C.malloc(C.size_t(outlen))
+ defer C.free(outbuf)
+
+ rv := C.scrypt_kdf(
+ (*C.uint8_t)(passwordbuf),
+ C.size_t(len(password)),
+ (*C.uint8_t)(saltbuf),
+ C.size_t(len(salt)),
+ C.uint64_t(N),
+ C.uint32_t(r),
+ C.uint32_t(p),
+ (*C.uint8_t)(outbuf),
+ C.size_t(outlen),
+ )
+ if rv != 0 {
+ return nil, ErrInternal
}
- return buffer, nil
-}
-func Salt() ([]byte, error) {
- return SaltFrom(rand.Reader)
+ out := C.GoBytes(outbuf, C.int(outlen))
+ return out, nil
}
func Hash(password []byte, salt []byte) ([]byte, error) {
- if len(salt) < saltMinLength {
+ if len(salt) < _SALT_MIN_LENGTH {
return nil, ErrSaltTooSmall
}
@@ -367,7 +105,7 @@ func Hash(password []byte, salt []byte) ([]byte, error) {
_N,
r,
p,
- desiredLength,
+ _DESIRED_LENGTH,
)
if err != nil {
return nil, err
@@ -376,6 +114,19 @@ func Hash(password []byte, salt []byte) ([]byte, error) {
return hash, nil
}
+func SaltFrom(r io.Reader) ([]byte, error) {
+ buffer := make([]byte, _SALT_MIN_LENGTH)
+ _, err := io.ReadFull(r, buffer)
+ if err != nil {
+ return nil, err
+ }
+ return buffer, nil
+}
+
+func Salt() ([]byte, error) {
+ return SaltFrom(rand.Reader)
+}
+
func Check(password []byte, salt []byte, hash []byte) (bool, error) {
candidate, err := Hash(password, salt)
if err != nil {
@@ -392,8 +143,10 @@ func Main() {
fmt.Fprintf(os.Stderr, "Usage: scrypt PASSWORD SALT\n")
os.Exit(2)
}
+ password := os.Args[1]
+ salt := os.Args[2]
- payload, err := Hash([]byte(os.Args[1]), []byte(os.Args[2]))
+ payload, err := Hash([]byte(password), []byte(salt))
if err != nil {
if err == ErrSaltTooSmall {
fmt.Fprintln(os.Stderr, err)
generated by cgit v1.2.3 (git 2.49.0) at 2025-07-13 22:04:21 +0000