public static void KeyExchange(ArraySegment <byte> sharedKey, ArraySegment <byte> publicKey,
ArraySegment <byte> privateKey)
{
if (sharedKey.Array == null)
{
throw new ArgumentNullException(nameof(sharedKey));
}
if (publicKey.Array == null)
{
throw new ArgumentNullException(nameof(sharedKey));
}
if (privateKey.Array == null)
{
throw new ArgumentNullException("privateKey");
}
if (sharedKey.Count != 32)
{
throw new ArgumentException("sharedKey.Count != 32");
}
if (publicKey.Count != 32)
{
throw new ArgumentException("publicKey.Count != 32");
}
if (privateKey.Count != 64)
{
throw new ArgumentException("privateKey.Count != 64");
}
FieldOperations.fe_frombytes(out FieldElement edwardsY, publicKey.Array, publicKey.Offset);
FieldOperations.fe_1(out FieldElement edwardsZ);
MontgomeryCurve25519.EdwardsToMontgomeryX(out FieldElement montgomeryX, ref edwardsY, ref edwardsZ);
byte[] h = Sha512.Hash(privateKey.Array, privateKey.Offset, 32);
ScalarOperations.ScClamp(h, 0);
MontgomeryOperations.ScalarMult(out FieldElement sharedMontgomeryX, h, 0, ref montgomeryX);
CryptoBytes.Wipe(h);
FieldOperations.fe_tobytes(sharedKey.Array, sharedKey.Offset, ref sharedMontgomeryX);
MontgomeryCurve25519.KeyExchangeOutputHashNaCl(sharedKey.Array, sharedKey.Offset);
}
public void Finish(ArraySegment <byte> output)
{
if (output.Array == null)
{
throw new ArgumentNullException(nameof(output));
}
if (output.Count != 64)
{
throw new ArgumentException("output.Count must be 64");
}
Update(Padding, 0, Padding.Length);
ByteIntegerConverter.Array16LoadBigEndian64(out Array16 <ulong> block, _buffer, 0);
CryptoBytes.InternalWipe(_buffer, 0, _buffer.Length);
int bytesInBuffer = (int)_totalBytes & (BlockSize - 1);
if (bytesInBuffer > BlockSize - 16)
{
Sha512Internal.Core(out _state, ref _state, ref block);
block = default(Array16 <ulong>);
}
block.x15 = (_totalBytes - 1) * 8;
Sha512Internal.Core(out _state, ref _state, ref block);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 0, _state.x0);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 8, _state.x1);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 16, _state.x2);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 24, _state.x3);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 32, _state.x4);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 40, _state.x5);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 48, _state.x6);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 56, _state.x7);
_state = default(Array8 <ulong>);
}
public void Update(byte[] data, int offset, int count)
{
if (data == null)
{
throw new ArgumentNullException(nameof(data));
}
if (offset < 0)
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
if (count < 0)
{
throw new ArgumentOutOfRangeException(nameof(count));
}
if (data.Length - offset < count)
{
throw new ArgumentException("Requires offset + count <= data.Length");
}
Array16 <ulong> block;
int bytesInBuffer = (int)_totalBytes & (BlockSize - 1);
_totalBytes += (uint)count;
if (_totalBytes >= ulong.MaxValue / 8)
{
throw new InvalidOperationException("Too much data");
}
// Fill existing buffer
if (bytesInBuffer != 0)
{
int toCopy = Math.Min(BlockSize - bytesInBuffer, count);
Buffer.BlockCopy(data, offset, _buffer, bytesInBuffer, toCopy);
offset += toCopy;
count -= toCopy;
bytesInBuffer += toCopy;
if (bytesInBuffer == BlockSize)
{
ByteIntegerConverter.Array16LoadBigEndian64(out block, _buffer, 0);
Sha512Internal.Core(out _state, ref _state, ref block);
CryptoBytes.InternalWipe(_buffer, 0, _buffer.Length);
bytesInBuffer = 0;
}
}
// Hash complete blocks without copying
while (count >= BlockSize)
{
ByteIntegerConverter.Array16LoadBigEndian64(out block, data, offset);
Sha512Internal.Core(out _state, ref _state, ref block);
offset += BlockSize;
count -= BlockSize;
}
// Copy remainder into buffer
if (count > 0)
{
Buffer.BlockCopy(data, offset, _buffer, bytesInBuffer, count);
}
}
public static byte[] ExpandedPrivateKeyFromSeed(byte[] privateKeySeed)
{
KeyPairFromSeed(out byte[] publicKey, out byte[] privateKey, privateKeySeed);
CryptoBytes.Wipe(publicKey);
return(privateKey);
}