RSA是一种被广泛接受并实现,提供私钥加密和公钥解密或者私钥加密公钥解密的算法。相对比较慢,底层是大数字因子分解。
package password.rsa;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import javax.crypto.Cipher;
import org.apache.commons.codec.binary.Base64;
public class RSA2 {
public static String RSA = "RSA";
private static final String src = "password";
public static void main(String[] args) {
try {
jdkRSA();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// rsa实现非对称加密
public static void jdkRSA() throws Exception {
// 1.初始化密钥
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(RSA);
keyPairGenerator.initialize(512);
KeyPair generateKeyPair = keyPairGenerator.generateKeyPair();
// 初始化公钥
RSAPublicKey rsaPublicKey = (RSAPublicKey) generateKeyPair.getPublic();
// 初始化私钥
RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) generateKeyPair.getPrivate();
System.out.println("public key公钥:" + Base64.encodeBase64String(rsaPublicKey.getEncoded()));
System.out.println("private key私钥:" + Base64.encodeBase64String(rsaPrivateKey.getEncoded()));
// 2.私钥加密——公钥解密,加密:
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());
KeyFactory keyFactory = KeyFactory.getInstance(RSA);
PrivateKey generatePrivate = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
Cipher instance = Cipher.getInstance(RSA);
instance.init(Cipher.ENCRYPT_MODE, rsaPrivateKey);
byte[] doFinal = instance.doFinal(src.getBytes());
System.out.println("用公钥加密,私钥解密——加密:" + Base64.encodeBase64String(doFinal));
// 3.私钥加密——公钥解密:解密:
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());
keyFactory = KeyFactory.getInstance(RSA);
PublicKey generatePublic = keyFactory.generatePublic(x509EncodedKeySpec);
Cipher instance2 = Cipher.getInstance(RSA);
instance2.init(Cipher.DECRYPT_MODE, generatePublic);
doFinal = instance2.doFinal(doFinal);
System.out.println("公钥解密结果:" + new String(doFinal));
// 4.公钥加密——私钥解密,加密:
x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());
keyFactory = KeyFactory.getInstance(RSA);
generatePublic = keyFactory.generatePublic(x509EncodedKeySpec);
instance2 = Cipher.getInstance(RSA);
instance2.init(Cipher.ENCRYPT_MODE, generatePublic);
doFinal = instance2.doFinal(src.getBytes());
System.out.println("公钥加密结果:" + Base64.encodeBase64String(doFinal));
// 5.公钥加密——私钥解密,解密:
new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());
keyFactory = KeyFactory.getInstance(RSA);
generatePrivate = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
instance = Cipher.getInstance(RSA);
instance.init(Cipher.DECRYPT_MODE, rsaPrivateKey);
doFinal = instance.doFinal(doFinal);
System.out.println("用私钥加密,公钥解密——解密:" + new String(doFinal));
}
}