| package org.bouncycastle.crypto.params; |
| |
| import java.io.EOFException; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.security.SecureRandom; |
| |
| import org.bouncycastle.math.ec.rfc7748.X25519; |
| import org.bouncycastle.util.Arrays; |
| import org.bouncycastle.util.io.Streams; |
| |
| public final class X25519PrivateKeyParameters |
| extends AsymmetricKeyParameter |
| { |
| public static final int KEY_SIZE = X25519.SCALAR_SIZE; |
| public static final int SECRET_SIZE = X25519.POINT_SIZE; |
| |
| private final byte[] data = new byte[KEY_SIZE]; |
| |
| public X25519PrivateKeyParameters(SecureRandom random) |
| { |
| super(true); |
| |
| X25519.generatePrivateKey(random, data); |
| } |
| |
| public X25519PrivateKeyParameters(byte[] buf, int off) |
| { |
| super(true); |
| |
| System.arraycopy(buf, off, data, 0, KEY_SIZE); |
| } |
| |
| public X25519PrivateKeyParameters(InputStream input) throws IOException |
| { |
| super(true); |
| |
| if (KEY_SIZE != Streams.readFully(input, data)) |
| { |
| throw new EOFException("EOF encountered in middle of X25519 private key"); |
| } |
| } |
| |
| public void encode(byte[] buf, int off) |
| { |
| System.arraycopy(data, 0, buf, off, KEY_SIZE); |
| } |
| |
| public byte[] getEncoded() |
| { |
| return Arrays.clone(data); |
| } |
| |
| public X25519PublicKeyParameters generatePublicKey() |
| { |
| byte[] publicKey = new byte[X25519.POINT_SIZE]; |
| X25519.generatePublicKey(data, 0, publicKey, 0); |
| return new X25519PublicKeyParameters(publicKey, 0); |
| } |
| |
| public void generateSecret(X25519PublicKeyParameters publicKey, byte[] buf, int off) |
| { |
| byte[] encoded = new byte[X25519.POINT_SIZE]; |
| publicKey.encode(encoded, 0); |
| if (!X25519.calculateAgreement(data, 0, encoded, 0, buf, off)) |
| { |
| throw new IllegalStateException("X25519 agreement failed"); |
| } |
| } |
| } |