RSA非对称加密工具JAVA实现

第三方服务与交易系统交互，需要对交易数据进行安全性较高的加密，采用RSA加密。
本文分享java实现的RSA加密工具类，及在linux环境中公私密钥对的生成

生成密钥对，在linux下
1. 生成私钥 (也可以用2048，但是加密过程负责)

openssl genrsa -out private.pem 1024

2. 生成公钥

openssl rsa -in private.pem -pubout -out public.pem

3. 私钥转码
(某些语言需要pkcs8格式的公钥, 否则报错
Java报错：java.security.spec.InvalidKeySpecException: java.security.InvalidKeyException: IOException : algid parse error, not a sequence)
openssl pkcs8 -topk8 -inform PEM -in private.pem -outform PEM -nocrypt

将1,2,3步后得到的密钥对作为公私密钥

直接上代码，注意可加密的长度，超出会报错 javax.crypto.IllegalBlockSizeException: Data must not be longer than 117 bytes

package cipher;

import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.Cipher;

import org.apache.commons.codec.binary.Base64;

public class RSACodeUtil {

public static final String KEY_ALGORTHM = "RSA";

private static final String publicKeyStr = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC2R1XOJeXrCYAsKOHA7ELiIVzrfrFI7eD9LexmFe0Gs2i47zhoicTUP2MKvU5/s14Ze0fLeDe8hG8To+hL7oviTH4MF8SpY+lojj7vUMBzeu3v5Q1Px2VW1eNJ0aE7Bs1V7+LMYl/tjWIQbaFHxEXfguzb9X0o/SANSwS5cUyVzQIDAQAB";
private static final String privateKeyStr = "MIICdgIBADANBgkqhkiG9w0BAQEFAASCAmAwggJcAgEAAoGBALZHVc4l5esJgCwo4cDsQuIhXOt+sUjt4P0t7GYV7QazaLjvOGiJxNQ/Ywq9Tn+zXhl7R8t4N7yEbxOj6Evui+JMfgwXxKlj6WiOPu9QwHN67e/lDU/HZVbV40nRoTsGzVXv4sxiX+2NYhBtoUfERd+C7Nv1fSj9IA1LBLlxTJXNAgMBAAECgYAFm2woS0InWMN4mElZhesIyb3yAJOzip3BLAh5m3MPIbW2+qThkltbrBd/3RLtGrdqUUCEIc6VHf3MvN4Id+4VmriQdTFi9SEr7GxVGJbHAstQrKfglyFPDhYTIFikDvxl4D98cEXy74Epr5wwgnQbQFi8+Z+Wp+vt5UW/MPSkgQJBAN9wT17D2rEW+VC8xJnJ8tAEfZDDUDvqfL8BQ0NXQri7HGYvsFMSax5rek5cjJVPangKUImOY3+5M/xf3geSbYMCQQDQ134F+a1c9t9KrqwfGx/1yoeqkXWDHJsunMrR38KC1q/OGR4fQOlcKDaILFXEucvXla2pUkqhpRgjg8hGs15vAkEAqj75ytvyMsKtfm4GYqN0Jjl1ryqSZMS6/hIpPRMs3HJ9JgMqF3HOOqRr0W9FErMrDYHWcakTeQsVaDNnil9wnwJAZ7Y8bXc6suoepZXtAF2WF5gGm5w1AXGZVyKiTmuSyysWj4FFxjuUKCIIQsPRrCqgomVAos+tJG06eZieQw4cnQJATuVeuGSu8zy8cm2r93KZ+mlqSu7ijwY2BjRI/1rqWF4dhScfZ+aLw72O7I8yPbeKEOWRZuHfzLEajOA3b4/wCg==";

private static String encrypt(String content, PrivateKey privateKey) throws Exception{
String encodeContent = null;
Cipher cipher = Cipher.getInstance( "rsa" );
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
Base64 base64 = new Base64();
byte [] cipherData = cipher.doFinal(content.getBytes());
encodeContent = base64.encodeToString(cipherData);
return encodeContent;
}

private static String decrypt(String content, PublicKey publicKey) throws Exception{
Base64 base64 = new Base64();
byte[] byteArray = base64.decodeBase64(content);
String decodeContent = null;
Cipher cipher = Cipher.getInstance( "rsa" );
cipher.init(Cipher.DECRYPT_MODE, publicKey);
byte [] cipherData = cipher.doFinal(byteArray);
return new String(cipherData);
}

private static PrivateKey getPrivateKey(String privateKeyStr2) throws Exception {

byte[] keyBytes = decryptBASE64(privateKeyStr2);

PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory;
keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
return privateKey;
}

private static PublicKey getPublicKey(String publicKey) throws Exception{
byte[] keyBytes = decryptBASE64(publicKey);
//构造X509EncodedKeySpec对象
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(keyBytes);
//指定加密算法
KeyFactory keyFactory;
keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
PublicKey publicKey2 = keyFactory.generatePublic(x509EncodedKeySpec);
return publicKey2;
}

private static byte[] decryptBASE64(String keys) {
Base64 base64 = new Base64();
return base64.decode(keys);
}

public static String encode(String content) throws Exception{
return encrypt(content, getPrivateKey(privateKeyStr));
}

public static String decode(String content) throws Exception{
return decrypt(content, getPublicKey(publicKeyStr));
}

public static void main(String[] args) {
try {
String content = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz";
//			String content = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz";
String code = encode(content);
System.out.println("code:"+code);
String content2 = decode(code);
System.out.println("content:"+content2);
} catch (Exception e) {
e.printStackTrace();
}
}
}

彩蛋，使用RSA推荐阅读 http://blog.csdn.net/defonds/article/details/42775183