package test;import java.io.*;import java.security.*;
import javax.crypto.*;import javax.crypto.spec.*;import java.security.spec.X509EncodedKeySpec;import java.security.spec.PKCS8EncodedKeySpec;import sun.misc.*;
/*** <p>Title: RSA非对称型加密的公钥和私钥</p>* <p>Description: </p>* <p>Copyright: Copyright (c) 2003</p>* <p>Company: </p>* @author not attributable* @version 1.0*/
public class RSAUtil { private KeyPairGenerator kpg = null; private KeyPair kp = null; private PublicKey public_key = null; private PrivateKey private_key = null;
/** * 构造函数 * @param in 指定密匙长度（取值范围：512～2048） * @throws NoSuchAlgorithmException 异常 */ public RSAUtils(int in, String address) throws NoSuchAlgorithmException, FileNotFoundException, IOException { kpg = KeyPairGenerator.getInstance("RSA"); //创建‘密匙对’生成器 kpg.initialize(in); //指定密匙长度（取值范围：512～2048） kp = kpg.genKeyPair(); //生成‘密匙对’，其中包含着一个公匙和一个私匙的信息 public_key = kp.getPublic(); //获得公匙 private_key = kp.getPrivate(); //获得私匙 sun.misc.BASE64Encoder b64 = new sun.misc.BASE64Encoder(); String pkStr = b64.encode(public_key.getEncoded()); String prStr = b64.encode(private_key.getEncoded()); System.out.print("pkStr length:" +pkStr.length() +pkStr);
FileWriter fw=new FileWriter(address + "/private_key.dat"); fw.write(prStr); fw.close(); FileWriter fw2 = new FileWriter(address + "/public_key.dat"); fw2.write(pkStr); fw2.close(); }
/** *加密的方法 */ private static String encrypt(String source) throws Exception{ /** 将文件中的公钥对象读出 */ FileReader fr = new FileReader("c://public_key.dat"); BufferedReader br=new BufferedReader(fr);//建立BufferedReader对象，并实例化为br String getPbKey = ""; while(true){ String aLine = br.readLine(); if(aLine==null)break; getPbKey += aLine; } System.out.println( "myBuilderStr : length: " + getPbKey.length() +"
"+getPbKey ); BASE64Decoder b64d = new BASE64Decoder(); byte [] keyByte = b64d.decodeBuffer(getPbKey); X509EncodedKeySpec x509ek = new X509EncodedKeySpec(keyByte); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); PublicKey publicKey = keyFactory.generatePublic(x509ek); Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE,publicKey); byte[] sbt = source.getBytes(); byte [] epByte = cipher.doFinal(sbt); BASE64Encoder encoder = new BASE64Encoder(); String epStr = encoder.encode(epByte); return epStr;
} /** *解密的方法 */ public static String decrypt(String cryptograph) throws Exception{ FileReader fr = new FileReader("c://private_key.dat"); BufferedReader br=new BufferedReader(fr);//建立BufferedReader对象，并实例化为
br String getPvKey = ""; while(true){ String aLine = br.readLine(); if(aLine==null)break; getPvKey += aLine; } BASE64Decoder b64d = new BASE64Decoder(); byte [] keyByte = b64d.decodeBuffer(getPvKey); PKCS8EncodedKeySpec s8ek = new PKCS8EncodedKeySpec(keyByte); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); PrivateKey privateKey = keyFactory.generatePrivate(s8ek); /** 得到Cipher对象对已用公钥加密的数据进行RSA解密 */ Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.DECRYPT_MODE, privateKey); BASE64Decoder decoder = new BASE64Decoder(); byte[] b1 = decoder.decodeBuffer(cryptograph); /** 执行解密操作 */ byte[] b = cipher.doFinal(b1); return new String(b); }
public static void main(String[] args) { try { new KeyRSA(1024, "D:/"); //私匙和公匙保存到D盘下的文件中. System.out.println(""); String getEptStr = encrypt("fengyupeng"); System.out.println("getEptStr:"+getEptStr); String drpStr = decrypt(getEptStr); System.out.println("drpStr:"+drpStr); } catch (IOException ex) { ex.printStackTrace(); } catch (NoSuchAlgorithmException ex) { ex.printStackTrace(); }catch(Exception ex){ ex.printStackTrace(); }
}
}
