publicexample.java

非常有用的加密解密程序

package ss.logic;
import java.security.Key;
import javax.crypto.Cipher;
import java.security.KeyPairGenerator;
import java.security.KeyPair;
import java.security.*;

public class PublicExample{
	public static void main(String[] args) throws Exception{

		String plainTextStr = "ABCDFDFEFERE";
		byte[] plainText = plainTextStr.getBytes("UTF8");
		System.out.println(plainTextStr);
		
		KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA");
		SecureRandom secrand = new SecureRandom();
		secrand.setSeed("CSR".getBytes());
		keyGen.initialize(1024, secrand);
		KeyPair key = keyGen.generateKeyPair();

		Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
		cipher.init(Cipher.ENCRYPT_MODE,key.getPublic());
		byte[] cipherText = cipher.doFinal(plainText);
		System.out.println(new String(cipherText, "UTF8"));

		cipher.init(Cipher.DECRYPT_MODE,key.getPrivate());
		byte[] newPlainText=cipher.doFinal(cipherText);
		System.out.println(new String(newPlainText, "UTF8"));
		
		
		
		
		
	
		String myinfo = "orderId=10dkfadsdfdffksdkssdkd&amount=80&orderTime=20060509";
		Signature signet = Signature.getInstance("MD5withRSA");
		signet.initSign(key.getPrivate());
		signet.update(myinfo.getBytes());
		byte[] signed = signet.sign();
		System.out.println("signed=" + new String(signed));
	//	System.out.println("info=" + myinfo);
		
	
		String info = "orderId=10dkfadsdfdffksdkssdkd&amount=80&orderTime=20060509";
		signet.initVerify(key.getPublic());
		
	//	System.out.println(info.getBytes());
	//	System.out.println(info.getBytes());
		
		signet.update(info.getBytes());

		if (signet.verify(signed)) {
			//System.out.println("info=" + info);
			System.out.println("yes!!");
			}
		else System.out.println("Wrong!!");
			
		
	}
}