org.bouncycastle.crypto.params.Ed25519PrivateKeyParameters.java Source code

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Here is the source code for org.bouncycastle.crypto.params.Ed25519PrivateKeyParameters.java

Source

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.rfc8032.Ed25519;
import org.bouncycastle.util.Arrays;
import org.bouncycastle.util.io.Streams;

public final class Ed25519PrivateKeyParameters extends AsymmetricKeyParameter {
    public static final int KEY_SIZE = Ed25519.SECRET_KEY_SIZE;
    public static final int SIGNATURE_SIZE = Ed25519.SIGNATURE_SIZE;

    private final byte[] data = new byte[KEY_SIZE];

    public Ed25519PrivateKeyParameters(SecureRandom random) {
        super(true);

        Ed25519.generatePrivateKey(random, data);
    }

    public Ed25519PrivateKeyParameters(byte[] buf, int off) {
        super(true);

        System.arraycopy(buf, off, data, 0, KEY_SIZE);
    }

    public Ed25519PrivateKeyParameters(InputStream input) throws IOException {
        super(true);

        if (KEY_SIZE != Streams.readFully(input, data)) {
            throw new EOFException("EOF encountered in middle of Ed25519 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 Ed25519PublicKeyParameters generatePublicKey() {
        byte[] publicKey = new byte[Ed25519.PUBLIC_KEY_SIZE];
        Ed25519.generatePublicKey(data, 0, publicKey, 0);
        return new Ed25519PublicKeyParameters(publicKey, 0);
    }

    public void sign(int algorithm, Ed25519PublicKeyParameters publicKey, byte[] ctx, byte[] msg, int msgOff,
            int msgLen, byte[] sig, int sigOff) {
        byte[] pk = new byte[Ed25519.PUBLIC_KEY_SIZE];
        if (null == publicKey) {
            Ed25519.generatePublicKey(data, 0, pk, 0);
        } else {
            publicKey.encode(pk, 0);
        }

        switch (algorithm) {
        case Ed25519.Algorithm.Ed25519: {
            if (null != ctx) {
                throw new IllegalArgumentException("ctx");
            }

            Ed25519.sign(data, 0, pk, 0, msg, msgOff, msgLen, sig, sigOff);
            break;
        }
        case Ed25519.Algorithm.Ed25519ctx: {
            Ed25519.sign(data, 0, pk, 0, ctx, msg, msgOff, msgLen, sig, sigOff);
            break;
        }
        case Ed25519.Algorithm.Ed25519ph: {
            if (Ed25519.PREHASH_SIZE != msgLen) {
                throw new IllegalArgumentException("msgLen");
            }

            Ed25519.signPrehash(data, 0, pk, 0, ctx, msg, msgOff, sig, sigOff);
            break;
        }
        default: {
            throw new IllegalArgumentException("algorithm");
        }
        }
    }
}