X25519PrivateKeyParameters
using Org.BouncyCastle.Math.EC.Rfc7748;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities;
using Org.BouncyCastle.Utilities.IO;
using System;
using System.IO;
namespace Org.BouncyCastle.Crypto.Parameters
{
public sealed class X25519PrivateKeyParameters : AsymmetricKeyParameter
{
public static readonly int KeySize = 32;
public static readonly int SecretSize = 32;
private readonly byte[] data = new byte[KeySize];
internal ReadOnlySpan<byte> DataSpan => data;
internal ReadOnlyMemory<byte> DataMemory => data;
public X25519PrivateKeyParameters(SecureRandom random)
: base(true)
{
X25519.GeneratePrivateKey(random, data);
}
public X25519PrivateKeyParameters(byte[] buf)
: this(Validate(buf), 0)
{
}
public X25519PrivateKeyParameters(byte[] buf, int off)
: base(true)
{
Array.Copy(buf, off, data, 0, KeySize);
}
public X25519PrivateKeyParameters(ReadOnlySpan<byte> buf)
: base(true)
{
if (buf.Length != KeySize)
throw new ArgumentException("must have length " + KeySize.ToString(), "buf");
buf.CopyTo(data);
}
public X25519PrivateKeyParameters(Stream input)
: base(true)
{
if (KeySize != Streams.ReadFully(input, data))
throw new EndOfStreamException("EOF encountered in middle of X25519 private key");
}
public void Encode(byte[] buf, int off)
{
Array.Copy(data, 0, buf, off, KeySize);
}
public void Encode(Span<byte> buf)
{
data.CopyTo(buf);
}
public byte[] GetEncoded()
{
return Arrays.Clone(data);
}
public unsafe X25519PublicKeyParameters GeneratePublicKey()
{
Span<byte> span = new Span<byte>(stackalloc byte[32], 32);
X25519.GeneratePublicKey(data, span);
return new X25519PublicKeyParameters(span);
}
public void GenerateSecret(X25519PublicKeyParameters publicKey, byte[] buf, int off)
{
GenerateSecret(publicKey, buf.AsSpan(off));
}
public unsafe void GenerateSecret(X25519PublicKeyParameters publicKey, Span<byte> buf)
{
Span<byte> span = new Span<byte>(stackalloc byte[32], 32);
publicKey.Encode(span);
if (!X25519.CalculateAgreement(data, span, buf))
throw new InvalidOperationException("X25519 agreement failed");
}
private static byte[] Validate(byte[] buf)
{
if (buf.Length != KeySize)
throw new ArgumentException("must have length " + KeySize.ToString(), "buf");
return buf;
}
}
}