IBESystemParameter.java

package hamaster.gradesgin.ibe;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.util.Arrays;

/**
 * IBE系统参数 包含系统公共参数和系统主密钥
 * The system parameter of an IBE system, containing the public parameter and system master key.
 * @author <a href="mailto:wangyeee@gmail.com">Wang Ye</a>
 */
public class IBESystemParameter implements Serializable, IBEConstraints {
	private static final long serialVersionUID = 784755162095627372L;

	/**
	 * 公共参数
	 * The public key
	 */
	protected IBEPublicParameter publicParameter;

	/**
	 * 主密钥
	 * The system master key, all user private keys are generated from this key.
	 */
	protected byte[] masterKey;

	public IBESystemParameter() {
	}

	public IBEPublicParameter getPublicParameter() {
		return publicParameter;
	}

	public void setPublicParameter(IBEPublicParameter publicParameter) {
		this.publicParameter = publicParameter;
	}

	public byte[] getMasterKey() {
		return masterKey;
	}

	public void setMasterKey(byte[] masterKey) {
		this.masterKey = masterKey;
	}

	/*
	 * (non-Javadoc)
	 * @see java.lang.Object#hashCode()
	 */
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + Arrays.hashCode(masterKey);
		result = prime * result + ((publicParameter == null) ? 0 : publicParameter.hashCode());
		return result;
	}

	/*
	 * (non-Javadoc)
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (!(obj instanceof IBESystemParameter))
			return false;
		IBESystemParameter other = (IBESystemParameter) obj;
		if (!Arrays.equals(masterKey, other.masterKey))
			return false;
		if (publicParameter == null) {
			if (other.publicParameter != null)
				return false;
		} else if (!publicParameter.equals(other.publicParameter))
			return false;
		return true;
	}

	/*
	 * (non-Javadoc)
	 * @see java.lang.Object#toString()
	 */
	@Override
	public String toString() {
		return "IBESystemParameter [publicParameter=" + publicParameter
				+ ", masterKey=" + Arrays.toString(masterKey) + "]";
	}

	/*
	 * (non-Javadoc)
	 * @see hamaster.gradesgin.ibe.IBEConstraints#writeExternal(java.io.OutputStream)
	 */
	@Override
	public void writeExternal(OutputStream out) throws IOException {
		if (masterKey == null) {
			byte[] zero = new byte[IBE_ZR_SIZE];
			Arrays.fill(zero, (byte) 0);
			out.write(zero);
		} else {
			// TODO encryption is also needed to protect the master key with a password.
			out.write(masterKey);
		}
		if (publicParameter != null)
			publicParameter.writeExternal(out);
		out.flush();
	}

	/*
	 * (non-Javadoc)
	 * @see hamaster.gradesgin.ibe.IBEConstraints#readExternal(java.io.InputStream)
	 */
	@Override
	public void readExternal(InputStream in) throws IOException, ClassNotFoundException {
		this.masterKey = new byte[IBE_ZR_SIZE];
		if (IBE_ZR_SIZE != in.read(masterKey))
			throw new IOException("Not enough bytes for a SystemParameter");
		this.publicParameter = new IBEPublicParameter();
		publicParameter.readExternal(in);
	}
}