org.bouncycastle.bcpg.MPInteger.java Source code

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Here is the source code for org.bouncycastle.bcpg.MPInteger.java

Source

package org.bouncycastle.bcpg;

import java.io.*;
import java.math.BigInteger;

/**
 * a multiple precision integer
 */
public class MPInteger extends BCPGObject {
    BigInteger value = null;

    public MPInteger(BCPGInputStream in) throws IOException {
        int length = (in.read() << 8) | in.read();
        byte[] bytes = new byte[(length + 7) / 8];

        in.readFully(bytes);

        value = new BigInteger(1, bytes);
    }

    public MPInteger(BigInteger value) {
        if (value == null || value.signum() < 0) {
            throw new IllegalArgumentException("value must not be null, or negative");
        }

        this.value = value;
    }

    public BigInteger getValue() {
        return value;
    }

    public void encode(BCPGOutputStream out) throws IOException {
        int length = value.bitLength();

        out.write(length >> 8);
        out.write(length);

        byte[] bytes = value.toByteArray();

        if (bytes[0] == 0) {
            out.write(bytes, 1, bytes.length - 1);
        } else {
            out.write(bytes, 0, bytes.length);
        }
    }
}