public static string SHA256(string Input, ref string LogText, bool DEBUG = false)
{
SHA256Context CTX = new SHA256Context();
CTX.W = new uint[64];
CTX.H = new uint[8];
if (DEBUG)
{
LogText = LogText + $"p={Input}\n";
}
string[] Blocks = GetBlocks(Input);
SHA256Init(ref CTX, DefaultHValue);
foreach (string Block in Blocks)
{
byte[] InputBytes = StringToByteArray(Block);
uint[] InputBlock = ByteArrayToUintArray(InputBytes);
if (DEBUG)
{
LogText = LogText + "# begin of next block\n";
LogText = LogText + $"H \t=+0x{SHA256ToString(CTX)}\n";
LogText = LogText + $"W \t=+0x{Block}\n";
}
SHA256ProcessBlock(ref CTX, InputBlock, ref LogText, DEBUG);
}
return(SHA256ToString(CTX));
}
private static void SHA256Init(ref SHA256Context CTX, string H)
{
if (H != DefaultHValue)
{
int xPos = H.IndexOf('x');
if (xPos != -1)
{
string HCopy = H.Substring(xPos + 1, (H.Length - xPos - 1));
if (HCopy.Length == 64)
{
CTX.H[0] = Convert.ToUInt32(HCopy.Substring(0, 8), 16);
CTX.H[1] = Convert.ToUInt32(HCopy.Substring(8, 8), 16);
CTX.H[2] = Convert.ToUInt32(HCopy.Substring(16, 8), 16);
CTX.H[3] = Convert.ToUInt32(HCopy.Substring(24, 8), 16);
CTX.H[4] = Convert.ToUInt32(HCopy.Substring(32, 8), 16);
CTX.H[5] = Convert.ToUInt32(HCopy.Substring(40, 8), 16);
CTX.H[6] = Convert.ToUInt32(HCopy.Substring(48, 8), 16);
CTX.H[7] = Convert.ToUInt32(HCopy.Substring(56, 8), 16);
}
}
}
else
{
CTX.H[0] = 0x6a09e667;
CTX.H[1] = 0xbb67ae85;
CTX.H[2] = 0x3c6ef372;
CTX.H[3] = 0xa54ff53a;
CTX.H[4] = 0x510e527f;
CTX.H[5] = 0x9b05688c;
CTX.H[6] = 0x1f83d9ab;
CTX.H[7] = 0x5be0cd19;
}
}
private static string SHA256ToString(SHA256Context CTX)
{
string H0 = CTX.H[0].ToString("x8");
string H1 = CTX.H[1].ToString("x8");
string H2 = CTX.H[2].ToString("x8");
string H3 = CTX.H[3].ToString("x8");
string H4 = CTX.H[4].ToString("x8");
string H5 = CTX.H[5].ToString("x8");
string H6 = CTX.H[6].ToString("x8");
string H7 = CTX.H[7].ToString("x8");
return($"{H0}{H1}{H2}{H3}{H4}{H5}{H6}{H7}");
}
private static void SHA256ProcessBlock(ref SHA256Context CTX, uint[] Value, ref string LogText, bool DEBUG = false)
{
uint A, B, C, D, E, F, G, H, t1, t2;
for (int i = 0; i < 16; i++)
{
CTX.W[i] = Value[i];
}
for (int i = 16; i < 64; i++)
{
CTX.W[i] = SSIG1(CTX.W[i - 2]) + CTX.W[i - 7] + SSIG0(CTX.W[i - 15]) + CTX.W[i - 16];
}
A = CTX.H[0];
B = CTX.H[1];
C = CTX.H[2];
D = CTX.H[3];
E = CTX.H[4];
F = CTX.H[5];
G = CTX.H[6];
H = CTX.H[7];
for (int i = 0; i < 64; i++)
{
t1 = H + BSIG1(E) + CH(E, F, G) + K[i] + CTX.W[i];
t2 = BSIG0(A) + MAJ(A, B, C);
H = G;
G = F;
F = E;
E = D + t1;
D = C;
C = B;
B = A;
A = t1 + t2;
if (DEBUG)
{
LogText = LogText + $"R[{i.ToString("D2")}]=+0x{A.ToString("x8")}{B.ToString("x8")}{C.ToString("x8")}{D.ToString("x8")}{E.ToString("x8")}{F.ToString("x8")}{G.ToString("x8")}{H.ToString("x8")}\n";
}
}
CTX.H[0] += A;
CTX.H[1] += B;
CTX.H[2] += C;
CTX.H[3] += D;
CTX.H[4] += E;
CTX.H[5] += F;
CTX.H[6] += G;
CTX.H[7] += H;
}
