chovy-trans/PspCrypto/Security/Cryptography/SHAManagedHashProvider.cs

377 lines
13 KiB
C#

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using static System.Numerics.BitOperations;
namespace PspCrypto.Security.Cryptography
{
internal sealed class SHAManagedHashProvider : HashProvider
{
private int hashSizeInBytes;
private SHAManagedImplementationBase impl;
private MemoryStream buffer;
public SHAManagedHashProvider(string hashAlgorithmId)
{
switch (hashAlgorithmId)
{
case HashAlgorithmNames.SHA224:
impl = new SHA224ManagedImplementation();
hashSizeInBytes = 28;
break;
default:
throw new CryptographicException(string.Format("'{0}' is not a known hash algorithm.", hashAlgorithmId));
}
}
public override void AppendHashData(ReadOnlySpan<byte> data)
{
buffer ??= new MemoryStream(1000);
buffer.Write(data);
}
public override int FinalizeHashAndReset(Span<byte> destination)
{
GetCurrentHash(destination);
buffer = null;
return hashSizeInBytes;
}
public override int GetCurrentHash(Span<byte> destination)
{
Debug.Assert(destination.Length >= hashSizeInBytes);
impl.Initialize();
if (buffer != null)
{
impl.HashCore(buffer.GetBuffer(), 0, (int)buffer.Length);
}
impl.HashFinal().CopyTo(destination);
return hashSizeInBytes;
}
public override int HashSizeInBytes => hashSizeInBytes;
public override void Reset()
{
buffer = null;
impl.Initialize();
}
public override void Dispose(bool disposing)
{
}
private abstract class SHAManagedImplementationBase
{
public abstract void Initialize();
public abstract void HashCore(byte[] partIn, int ibStart, int cbSize);
public abstract byte[] HashFinal();
}
private sealed class SHA224ManagedImplementation : SHAManagedImplementationBase
{
private byte[] _buffer;
private long _count; // Number of bytes in the hashed message
private uint[] _stateSHA224;
private uint[] _W;
public SHA224ManagedImplementation()
{
_stateSHA224 = new uint[8];
_buffer = new byte[64];
_W = new uint[64];
InitializeState();
}
public override void Initialize()
{
InitializeState();
// Zeroize potentially sensitive information.
Array.Clear(_buffer, 0, _buffer.Length);
Array.Clear(_W, 0, _W.Length);
}
private void InitializeState()
{
_count = 0;
_stateSHA224[0] = 0xc1059ed8;
_stateSHA224[1] = 0x367cd507;
_stateSHA224[2] = 0x3070dd17;
_stateSHA224[3] = 0xf70e5939;
_stateSHA224[4] = 0xffc00b31;
_stateSHA224[5] = 0x68581511;
_stateSHA224[6] = 0x64f98fa7;
_stateSHA224[7] = 0xbefa4fa4;
}
/* SHA256 block update operation. Continues an SHA message-digest
operation, processing another message block, and updating the
context.
*/
public override unsafe void HashCore(byte[] partIn, int ibStart, int cbSize)
{
int bufferLen;
int partInLen = cbSize;
int partInBase = ibStart;
/* Compute length of buffer */
bufferLen = (int)(_count & 0x3f);
/* Update number of bytes */
_count += partInLen;
fixed (uint* stateSHA256 = _stateSHA224)
{
fixed (byte* buffer = _buffer)
{
fixed (uint* expandedBuffer = _W)
{
if (bufferLen > 0 && bufferLen + partInLen >= 64)
{
Buffer.BlockCopy(partIn, partInBase, _buffer, bufferLen, 64 - bufferLen);
partInBase += 64 - bufferLen;
partInLen -= 64 - bufferLen;
SHATransform(expandedBuffer, stateSHA256, buffer);
bufferLen = 0;
}
/* Copy input to temporary buffer and hash */
while (partInLen >= 64)
{
Buffer.BlockCopy(partIn, partInBase, _buffer, 0, 64);
partInBase += 64;
partInLen -= 64;
SHATransform(expandedBuffer, stateSHA256, buffer);
}
if (partInLen > 0)
{
Buffer.BlockCopy(partIn, partInBase, _buffer, bufferLen, partInLen);
}
}
}
}
}
/* SHA256 finalization. Ends an SHA256 message-digest operation, writing
the message digest.
*/
public override byte[] HashFinal()
{
byte[] pad;
int padLen;
long bitCount;
byte[] hash = new byte[28]; // HashSizeValue = 224
/* Compute padding: 80 00 00 ... 00 00 <bit count>
*/
padLen = 64 - (int)(_count & 0x3f);
if (padLen <= 8)
padLen += 64;
pad = new byte[padLen];
pad[0] = 0x80;
// Convert count to bit count
bitCount = _count * 8;
pad[padLen - 8] = (byte)(bitCount >> 56 & 0xff);
pad[padLen - 7] = (byte)(bitCount >> 48 & 0xff);
pad[padLen - 6] = (byte)(bitCount >> 40 & 0xff);
pad[padLen - 5] = (byte)(bitCount >> 32 & 0xff);
pad[padLen - 4] = (byte)(bitCount >> 24 & 0xff);
pad[padLen - 3] = (byte)(bitCount >> 16 & 0xff);
pad[padLen - 2] = (byte)(bitCount >> 8 & 0xff);
pad[padLen - 1] = (byte)(bitCount >> 0 & 0xff);
/* Digest padding */
HashCore(pad, 0, pad.Length);
/* Store digest */
SHAUtils.DWORDToBigEndian(hash, _stateSHA224, 7);
return hash;
}
private static readonly uint[] _K = {
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
};
private static unsafe void SHATransform(uint* expandedBuffer, uint* state, byte* block)
{
uint a, b, c, d, e, f, h, g;
uint aa, bb, cc, dd, ee, ff, hh, gg;
uint T1;
a = state[0];
b = state[1];
c = state[2];
d = state[3];
e = state[4];
f = state[5];
g = state[6];
h = state[7];
// fill in the first 16 bytes of W.
SHAUtils.DWORDFromBigEndian(expandedBuffer, 16, block);
SHA256Expand(expandedBuffer);
/* Apply the SHA256 compression function */
// We are trying to be smart here and avoid as many copies as we can
// The perf gain with this method over the straightforward modify and shift
// forward is >= 20%, so it's worth the pain
for (int j = 0; j < 64;)
{
T1 = h + Sigma_1(e) + Ch(e, f, g) + _K[j] + expandedBuffer[j];
ee = d + T1;
aa = T1 + Sigma_0(a) + Maj(a, b, c);
j++;
T1 = g + Sigma_1(ee) + Ch(ee, e, f) + _K[j] + expandedBuffer[j];
ff = c + T1;
bb = T1 + Sigma_0(aa) + Maj(aa, a, b);
j++;
T1 = f + Sigma_1(ff) + Ch(ff, ee, e) + _K[j] + expandedBuffer[j];
gg = b + T1;
cc = T1 + Sigma_0(bb) + Maj(bb, aa, a);
j++;
T1 = e + Sigma_1(gg) + Ch(gg, ff, ee) + _K[j] + expandedBuffer[j];
hh = a + T1;
dd = T1 + Sigma_0(cc) + Maj(cc, bb, aa);
j++;
T1 = ee + Sigma_1(hh) + Ch(hh, gg, ff) + _K[j] + expandedBuffer[j];
h = aa + T1;
d = T1 + Sigma_0(dd) + Maj(dd, cc, bb);
j++;
T1 = ff + Sigma_1(h) + Ch(h, hh, gg) + _K[j] + expandedBuffer[j];
g = bb + T1;
c = T1 + Sigma_0(d) + Maj(d, dd, cc);
j++;
T1 = gg + Sigma_1(g) + Ch(g, h, hh) + _K[j] + expandedBuffer[j];
f = cc + T1;
b = T1 + Sigma_0(c) + Maj(c, d, dd);
j++;
T1 = hh + Sigma_1(f) + Ch(f, g, h) + _K[j] + expandedBuffer[j];
e = dd + T1;
a = T1 + Sigma_0(b) + Maj(b, c, d);
j++;
}
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
state[4] += e;
state[5] += f;
state[6] += g;
state[7] += h;
}
private static uint Ch(uint x, uint y, uint z)
{
return x & y ^ (x ^ 0xffffffff) & z;
}
private static uint Maj(uint x, uint y, uint z)
{
return x & y ^ x & z ^ y & z;
}
private static uint sigma_0(uint x)
{
return RotateRight(x, 7) ^ RotateRight(x, 18) ^ x >> 3;
}
private static uint sigma_1(uint x)
{
return RotateRight(x, 17) ^ RotateRight(x, 19) ^ x >> 10;
}
private static uint Sigma_0(uint x)
{
return RotateRight(x, 2) ^ RotateRight(x, 13) ^ RotateRight(x, 22);
}
private static uint Sigma_1(uint x)
{
return RotateRight(x, 6) ^ RotateRight(x, 11) ^ RotateRight(x, 25);
}
/* This function creates W_16,...,W_63 according to the formula
W_j <- sigma_1(W_{j-2}) + W_{j-7} + sigma_0(W_{j-15}) + W_{j-16};
*/
private static unsafe void SHA256Expand(uint* x)
{
for (int i = 16; i < 64; i++)
{
x[i] = sigma_1(x[i - 2]) + x[i - 7] + sigma_0(x[i - 15]) + x[i - 16];
}
}
}
private static class SHAUtils
{
// digits == number of DWORDs
public static unsafe void DWORDFromBigEndian(uint* x, int digits, byte* block)
{
int i;
int j;
for (i = 0, j = 0; i < digits; i++, j += 4)
x[i] = (uint)(block[j] << 24 | block[j + 1] << 16 | block[j + 2] << 8 | block[j + 3]);
}
// encodes x (DWORD) into block (unsigned char), most significant byte first.
// digits == number of DWORDs
public static void DWORDToBigEndian(byte[] block, uint[] x, int digits)
{
int i;
int j;
for (i = 0, j = 0; i < digits; i++, j += 4)
{
block[j] = (byte)(x[i] >> 24 & 0xff);
block[j + 1] = (byte)(x[i] >> 16 & 0xff);
block[j + 2] = (byte)(x[i] >> 8 & 0xff);
block[j + 3] = (byte)(x[i] & 0xff);
}
}
}
}
}