public static unsafe void Start(ReadOnlySpan <byte> prv32, ReadOnlySpan <byte> pub256)
{
Stopwatch timer = Stopwatch.StartNew();
int missCount = 1;
BigInteger a = 1;
BigInteger b = 1;
BigInteger c = 1;
byte[] ba32 = new byte[prv32.Length];
byte[] ba256 = new byte[32];
int *mi = stackalloc int[55 + 55];
int *items = mi + 55;
while (a > 0)
{
Console.WriteLine($"Checking {missCount} char wrong cases:");
a *= 56 - missCount;
b *= missCount;
c *= 32;
BigInteger total = (a / b) * c;
Console.WriteLine($"Going to check {total:n0} permutation...");
fixed(byte *b32 = &ba32[0], b256 = &ba256[0], p32 = &prv32[0])
{
for (int i = 0; i < missCount; i++)
{
mi[i] = i + 1;
items[i] = 0;
}
do
{
do
{
Buffer.MemoryCopy(p32, b32, ba32.Length, prv32.Length);
for (int i = 0; i < missCount; i++)
{
b32[mi[i]] = (byte)items[i];
}
byte version = (byte)(b32[0] << 3 | b32[1] >> 2);
if (version == Base32.PrvByte)
{
b256[0] = (byte)(b32[1] << 6 | b32[2] << 1 | b32[3] >> 4);
b256[1] = (byte)(b32[3] << 4 | b32[4] >> 1);
b256[2] = (byte)(b32[4] << 7 | b32[5] << 2 | b32[6] >> 3);
b256[3] = (byte)(b32[6] << 5 | b32[7]);
b256[4] = (byte)(b32[8] << 3 | b32[9] >> 2);
b256[5] = (byte)(b32[9] << 6 | b32[10] << 1 | b32[11] >> 4);
b256[6] = (byte)(b32[11] << 4 | b32[12] >> 1);
b256[7] = (byte)(b32[12] << 7 | b32[13] << 2 | b32[14] >> 3);
b256[8] = (byte)(b32[14] << 5 | b32[15]);
b256[9] = (byte)(b32[16] << 3 | b32[17] >> 2);
b256[10] = (byte)(b32[17] << 6 | b32[18] << 1 | b32[19] >> 4);
b256[11] = (byte)(b32[19] << 4 | b32[20] >> 1);
b256[12] = (byte)(b32[20] << 7 | b32[21] << 2 | b32[22] >> 3);
b256[13] = (byte)(b32[22] << 5 | b32[23]);
b256[14] = (byte)(b32[24] << 3 | b32[25] >> 2);
b256[15] = (byte)(b32[25] << 6 | b32[26] << 1 | b32[27] >> 4);
b256[16] = (byte)(b32[27] << 4 | b32[28] >> 1);
b256[17] = (byte)(b32[28] << 7 | b32[29] << 2 | b32[30] >> 3);
b256[18] = (byte)(b32[30] << 5 | b32[31]);
b256[19] = (byte)(b32[32] << 3 | b32[33] >> 2);
b256[20] = (byte)(b32[33] << 6 | b32[34] << 1 | b32[35] >> 4);
b256[21] = (byte)(b32[35] << 4 | b32[36] >> 1);
b256[22] = (byte)(b32[36] << 7 | b32[37] << 2 | b32[38] >> 3);
b256[23] = (byte)(b32[38] << 5 | b32[39]);
b256[24] = (byte)(b32[40] << 3 | b32[41] >> 2);
b256[25] = (byte)(b32[41] << 6 | b32[42] << 1 | b32[43] >> 4);
b256[26] = (byte)(b32[43] << 4 | b32[44] >> 1);
b256[27] = (byte)(b32[44] << 7 | b32[45] << 2 | b32[46] >> 3);
b256[28] = (byte)(b32[46] << 5 | b32[47]);
b256[29] = (byte)(b32[48] << 3 | b32[49] >> 2);
b256[30] = (byte)(b32[49] << 6 | b32[50] << 1 | b32[51] >> 4);
b256[31] = (byte)(b32[51] << 4 | b32[52] >> 1);
}
ushort actualCS = (ushort)((byte)(b32[52] << 7 | b32[53] << 2 | b32[54] >> 3) |
(b32[54] << 13 | b32[55] << 8));
// Compute checksum
ushort expectedCS = (ushort)(version << 8);
for (int j = 0; j < 8; j++)
{
expectedCS = (expectedCS & 0x8000) != 0 ?
(ushort)((expectedCS << 1) ^ 0x1021) :
(ushort)(expectedCS << 1);
}
expectedCS ^= (ushort)(b256[0] << 8);
for (int j = 0; j < 8; j++)
{
expectedCS = (expectedCS & 0x8000) != 0 ?
(ushort)((expectedCS << 1) ^ 0x1021) :
(ushort)(expectedCS << 1);
}
for (int i = 1; i < ba256.Length; i++)
{
expectedCS ^= (ushort)(b256[i] << 8);
for (int j = 0; j < 8; j++)
{
expectedCS = (expectedCS & 0x8000) != 0 ?
(ushort)((expectedCS << 1) ^ 0x1021) :
(ushort)(expectedCS << 1);
}
}
if (actualCS == expectedCS)
{
KeyPair keypair = KeyPair.FromSecretSeed(ba256);
if (pub256.SequenceEqual(keypair.PublicKey))
{
Console.WriteLine("Found the correct key:");
Console.WriteLine(Base32.Encode32(ba32));
timer.Stop();
Console.WriteLine($"Elapsed time: {timer.Elapsed}");
return;
}
}
} while (MoveNextItems(items, missCount, 32));
} while (MoveNextIndex(mi, missCount, 56));
Console.WriteLine($"Elapsed time: {timer.Elapsed}");
Console.WriteLine("====================================================");
timer.Restart();
missCount++;
}
}
}
