\feffusing System;
using System.Collections.Generic;
using System.Linq;
-using System.Text;
-using Medo.Security.Cryptography;
using System.Security.Cryptography;
namespace Novacoin
{
+ /// <summary>
+ /// Representation of scrypt hash
+ /// </summary>
public class ScryptHash256 : Hash
{
// 32 bytes
public ScryptHash256(byte[] bytesArray) : base(bytesArray) { }
public ScryptHash256(IList<byte> bytesList) : base(bytesList) { }
+ /// <summary>
+ /// Calculate scrypt hash and return new instance of ScryptHash256 class
+ /// </summary>
+ /// <param name="inputBytes">Byte sequence to hash</param>
+ /// <returns>Hashing result instance</returns>
public static ScryptHash256 Compute256(IEnumerable<byte> inputBytes)
{
- byte[] dataBytes = inputBytes.ToArray();
-
uint[] V = new uint[(131072 + 63) / sizeof(uint)];
- uint[] X = null;
- using (HMACSHA256 hmac = new HMACSHA256())
- {
- Pbkdf2 df = new Pbkdf2(hmac, dataBytes, dataBytes, 1);
- byte[] keyBytes1 = df.GetBytes(128);
-
- X = Interop.ToUInt32Array(keyBytes1);
- }
+ byte[] dataBytes = inputBytes.ToArray();
+ byte[] keyBytes1 = PBKDF2Sha256GetBytes(128, dataBytes, dataBytes, 1);
+ uint[] X = Interop.ToUInt32Array(keyBytes1);
- ushort i, j, k;
+ uint i, j, k;
for (i = 0; i < 1024; i++)
{
Array.Copy(X, 0, V, i * 32, 32);
}
for (i = 0; i < 1024; i++)
{
- j = (ushort)(32 * (X[16] & 1023));
+ j = 32 * (X[16] & 1023);
for (k = 0; k < 32; k++)
X[k] ^= V[j + k];
xor_salsa8(ref X, 0, ref X, 16);
}
byte[] xBytes = Interop.LEBytes(X);
+ byte[] keyBytes2 = PBKDF2Sha256GetBytes(32, dataBytes, xBytes, 1);
- byte[] keyBytes2 = null;
- using (HMACSHA256 hmac = new HMACSHA256())
+ return new ScryptHash256(keyBytes2);
+ }
+
+ private static byte[] PBKDF2Sha256GetBytes(int dklen, byte[] password, byte[] salt, int iterationCount)
+ {
+ using (var hmac = new HMACSHA256(password))
{
- Pbkdf2 df = new Pbkdf2(hmac, dataBytes, xBytes, 1);
- keyBytes2 = df.GetBytes(32);
+ int hashLength = hmac.HashSize / 8;
+ if ((hmac.HashSize & 7) != 0)
+ hashLength++;
+ int keyLength = dklen / hashLength;
+ if ((long)dklen > (0xFFFFFFFFL * hashLength) || dklen < 0)
+ throw new ArgumentOutOfRangeException("dklen");
+ if (dklen % hashLength != 0)
+ keyLength++;
+ byte[] extendedkey = new byte[salt.Length + 4];
+ Buffer.BlockCopy(salt, 0, extendedkey, 0, salt.Length);
+ using (var ms = new System.IO.MemoryStream())
+ {
+ for (int i = 0; i < keyLength; i++)
+ {
+ extendedkey[salt.Length] = (byte)(((i + 1) >> 24) & 0xFF);
+ extendedkey[salt.Length + 1] = (byte)(((i + 1) >> 16) & 0xFF);
+ extendedkey[salt.Length + 2] = (byte)(((i + 1) >> 8) & 0xFF);
+ extendedkey[salt.Length + 3] = (byte)(((i + 1)) & 0xFF);
+ byte[] u = hmac.ComputeHash(extendedkey);
+ Array.Clear(extendedkey, salt.Length, 4);
+ byte[] f = u;
+ for (int j = 1; j < iterationCount; j++)
+ {
+ u = hmac.ComputeHash(u);
+ for (int k = 0; k < f.Length; k++)
+ {
+ f[k] ^= u[k];
+ }
+ }
+ ms.Write(f, 0, f.Length);
+ Array.Clear(u, 0, u.Length);
+ Array.Clear(f, 0, f.Length);
+ }
+ byte[] dk = new byte[dklen];
+ ms.Position = 0;
+ ms.Read(dk, 0, dklen);
+ ms.Position = 0;
+ for (long i = 0; i < ms.Length; i++)
+ {
+ ms.WriteByte(0);
+ }
+ Array.Clear(extendedkey, 0, extendedkey.Length);
+ return dk;
+ }
}
-
- return new ScryptHash256(keyBytes2);
}
private static void xor_salsa8(ref uint[] B, int indexB, ref uint[] Bx, int indexBx)