java/ecies-tool.java

import org.rivoreo.crypto.ECIES;
import org.rivoreo.crypto.ECIES_XTEA;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;

class ECIES_Tool {
	private static void keygen() throws IOException {
		//char buf[2 * ECIES_KEY_SIZE + 1];
		//ECIES.PrivateKey priv;
		//ECIES.PublicKey pub;
		//ECIES ecies = new ECIES_XTEA(ECIES.SECTDomainParameters.sect409r1);
		ECIES ecies = new ECIES_XTEA(ECIES.SECTDomainParameters.sect571r1);
		ECIES.PrivateKey priv = ecies.create_privatekey();
		ECIES.PublicKey pub = ecies.create_publickey();
		ecies.generate_keys(priv, pub);		/* generate a public/private key pair */
/*
		hex_dump(buf, pub.x, ECIES_KEY_SIZE); printf("%s:", buf);
		hex_dump(buf, pub.y, ECIES_KEY_SIZE); printf("%s\n", buf);
		hex_dump(buf, priv.k, ECIES_KEY_SIZE); printf("%s\n", buf);
*/
/*
		print_bytes(pub.x);
		System.out.print(':');
		print_bytes_line(pub.y);
		print_bytes_line(priv.k);
*/
/*
		System.out.printf("%s:%s\n%s\n",
			hex_dump(pub.x, pub.x.length),
			hex_dump(pub.y, pub.y.length),
			hex_dump(priv.k, priv.k.length));
*/
		FileOutputStream fos = new FileOutputStream("publickey");
		fos.write(pub.x);
		fos.write(pub.y);
		fos.close();
		fos = new FileOutputStream("privatekey");
		fos.write(priv.k);
		fos.close();
		System.out.println("publickey and privatekey are saved into current directory");
	}

	private static final int CHUNK_SIZE = 8 * 1024;

	private static int read_chunk(InputStream stm, byte[] raw, int offset, int len) throws IOException {
		len = stm.read(raw, offset, len);
		return len;
	}

	private static void write_all(OutputStream stm, final byte[] raw, int offset, int len) throws IOException {
		stm.write(raw, offset, len);
	}

	private static void encrypt(String pubkey) throws IOException {
		//ECIES ecies = new ECIES_XTEA(ECIES.SECTDomainParameters.sect409r1);
		ECIES ecies = new ECIES_XTEA(ECIES.SECTDomainParameters.sect571r1);
		ECIES.PublicKey pub = ecies.new PublicKey();
		//ECIES.PublicKey pub = ecies.create_publickey();
/*
		int len = load_bytes(pub.x, pubkey);
		if(len < 0) {
			System.err.println("Invalid public key x");
			return;
		}
		len = load_bytes(pub.y, pubkey.substring(len));
		if(len < 0) {
			System.err.println("Invalid public key y");
			return;
		}
*/
		FileInputStream fis = new FileInputStream(pubkey);
		fis.read(pub.x);
		fis.read(pub.y);
		fis.close();

		ECIES.Stream stm = ecies.new Stream();
		byte[] enc = new byte[ecies.ECIES_START_OVERHEAD];
		ecies.encrypt_start(stm, enc, pub);
		write_all(System.out, enc, 0, ecies.ECIES_START_OVERHEAD);

		enc = new byte[CHUNK_SIZE + ecies.ECIES_CHUNK_OVERHEAD];
		while(true) {
			int len = read_chunk(System.in, enc, 0, CHUNK_SIZE);
			if(len <= 0) return;
			ecies.encrypt_chunk(stm, enc, len);
			write_all(System.out, enc, 0, len + ecies.ECIES_CHUNK_OVERHEAD);
		}
	}

	private static void decrypt(String privkey) throws IOException {
		//ECIES ecies = new ECIES_XTEA(ECIES.SECTDomainParameters.sect409r1);
		ECIES ecies = new ECIES_XTEA(ECIES.SECTDomainParameters.sect571r1);
		ECIES.PrivateKey priv = ecies.new PrivateKey();
		//ECIES.PrivateKey priv = new ECIES.PrivateKey(ecies.getClass());
/*
		if(load_bytes(priv.k, privkey) < 0) {
			System.err.println("Invalid private key");
			return;
		}
*/
		FileInputStream fis = new FileInputStream(privkey);
		fis.read(priv.k);
		fis.close();

		ECIES.Stream stm = ecies.new Stream();
		byte[] enc = new byte[ecies.ECIES_START_OVERHEAD];
		int len = read_chunk(System.in, enc, 0, ecies.ECIES_START_OVERHEAD);
		if(len < ecies.ECIES_START_OVERHEAD) {
			System.err.printf("%d < %d\n", len, ecies.ECIES_START_OVERHEAD);
			return;
		}
		len = ecies.decrypt_start(stm, enc, priv);
		if(len < 0) {
			System.err.println("ecies.decrypt_start failed");
			return;
		}

		enc = new byte[CHUNK_SIZE + ecies.ECIES_CHUNK_OVERHEAD];
		while(true) {
			len = read_chunk(System.in, enc, 0, CHUNK_SIZE + ecies.ECIES_CHUNK_OVERHEAD);
			if(len <= 0) return;
			if(ecies.decrypt_chunk(stm, enc, len - ecies.ECIES_CHUNK_OVERHEAD) < 0) {
				System.err.println("decrypt_chunk failed");
				return;
			}
			write_all(System.out, enc, 0, len - ecies.ECIES_CHUNK_OVERHEAD);
		}
	}

	private static void print_usage() {
		System.err.println("Usage: ecies-tool <command> [parameters]\n" +
			"  [k]eygen -- generate public/private key pair\n" +
			"  [e]ncrypt [public-key-x:public-key-y] -- encrypt stdin to stdout using public key\n" +
			"  [d]ecrypt [private-key] -- decript stdin to stdout using private key\n");
	}

	public static void main(String[] a) throws IOException {
		if(a.length < 1 || (a[0].charAt(0) != 'k' && a.length < 2)) {
			print_usage();
			return;
		}
		switch(a[0].charAt(0)) {
			case 'k':
				//keygen(a.length > 1 ? a[1] : null);
				keygen();
				return;
			case 'e':
				encrypt(a[1]);
				return;
			case 'd':
				decrypt(a[1]);
				return;
		}
		print_usage();
	}
}