`package security;

import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.security.InvalidKeyException; import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.NoSuchAlgorithmException; import java.security.SecureRandom; import java.security.interfaces.RSAPrivateKey; import java.security.interfaces.RSAPublicKey; import java.security.spec.InvalidKeySpecException; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec;

import javax.crypto.BadPaddingException; import javax.crypto.Cipher; import javax.crypto.IllegalBlockSizeException; import javax.crypto.NoSuchPaddingException;

import sun.misc.BASE64Decoder; import sun.misc.BASE64Encoder;

public class RSAEncryptor {

public static void main(String[] args){  

    String privateKeyPath = "D:\\rsa\\rsa_public_key.pem";        // replace your public key path here
    String publicKeyPath =  "D:\\rsa\\pkcs8_private_key.pem";     // replace your private path here
   
    try {
    	RSAEncryptor rsaEncryptor = new RSAEncryptor(privateKeyPath, publicKeyPath);
        String test = "这是一个测试的ASR测试串";
        String testRSAEnWith64 = rsaEncryptor.encryptWithBase64(test);
        String testRSADeWith64 = rsaEncryptor.decryptWithBase64(testRSAEnWith64);
        System.out.println("\nEncrypt: \n" + testRSAEnWith64);
        System.out.println("\nDecrypt: \n" + testRSADeWith64);

        // NSLog the encrypt string from Xcode , and paste it here.
        // 请粘贴来自IOS端加密后的字符串
        String rsaBase46StringFromIOS ="EpPG0FsBVP+tHFXwvyynVBWGtHbCut83Jf8MdtrBVmEOgVNcibXtmHH7p9jxHjZSocHpWWUD1zUAVM90sNUEKWh/o2gdFhb4Vv3n8lwTD97ShTLRYSCucFUUzLyWO4gZU/VG+AYGMWCsq9DmW/pOPzd5TPGMEsi5EUFK+3YCt3w=";
        
        String decryptStringFromIOS = rsaEncryptor.decryptWithBase64(rsaBase46StringFromIOS);
        System.out.println("Decrypt result from ios client: \n" + decryptStringFromIOS);

    } catch (Exception e) {
        e.printStackTrace();
    }

}





/**
 * [@param](https://my.oschina.net/u/2303379) publicKeyFilePath     
 * [@param](https://my.oschina.net/u/2303379) privateKeyFilePath    
 */
public RSAEncryptor(String publicKeyFilePath, String privateKeyFilePath) throws Exception {
    String public_key = getKeyFromFile(publicKeyFilePath);
    String private_key = getKeyFromFile(privateKeyFilePath);
    loadPublicKey(public_key);  
    loadPrivateKey(private_key);  
}
public RSAEncryptor() {
    // load the PublicKey and PrivateKey manually
}

// public String getKeyFromFile(String filePath) throws Exception { // BufferedReader bufferedReader = new BufferedReader(new FileReader(filePath)); // String line = null; // List<String> list = new ArrayList<String>(); // while ((line = bufferedReader.readLine()) != null){ // list.add(line); // } // // remove the firt line and last line // StringBuilder stringBuilder = new StringBuilder(); // for (int i = 1; i < list.size() - 1; i++) { // stringBuilder.append(list.get(i)).append("\r"); // } // // String key = stringBuilder.toString(); // return key; // }

private static String getKeyFromFile(String fileName) {  
    BufferedReader br;  
    byte[] key = null; 
    String str = "";  
    try {  
        br = new BufferedReader(new FileReader(fileName));  
        String s = br.readLine();  
        s = br.readLine();  
        while (s.charAt(0) != '-') {  
            str += s + "\r";  
            s = br.readLine();  
        }  
        System.out.println(str);

// key = Base64.getDecoder().decode(str); // } catch (Exception ex) {
}
return str;
}

public String decryptWithBase64(String base64String) throws Exception {
    //  http://commons.apache.org/proper/commons-codec/ : org.apache.commons.codec.binary.Base64
    // sun.misc.BASE64Decoder
    byte[] binaryData = decrypt(getPrivateKey(), new BASE64Decoder().decodeBuffer(base64String) /*org.apache.commons.codec.binary.Base64.decodeBase64(base46String.getBytes())*/);
    String string = new String(binaryData);
    return string;
}

public String encryptWithBase64(String string) throws Exception {
    //  http://commons.apache.org/proper/commons-codec/ : org.apache.commons.codec.binary.Base64
    // sun.misc.BASE64Encoder
    byte[] binaryData = encrypt(getPublicKey(), string.getBytes());
    String base64String = new BASE64Encoder().encodeBuffer(binaryData) /* org.apache.commons.codec.binary.Base64.encodeBase64(binaryData) */;
    return base64String;
}



// convenient properties
public static RSAEncryptor sharedInstance = null;
public static void setSharedInstance (RSAEncryptor rsaEncryptor) {
    sharedInstance = rsaEncryptor;
}




// From: http://blog.csdn.net/chaijunkun/article/details/7275632

/** 
 * 私钥 
 */  
private RSAPrivateKey privateKey;  

/** 
 * 公钥 
 */  
private RSAPublicKey publicKey;  

/** 
 * 获取私钥 
 * [@return](https://my.oschina.net/u/556800) 当前的私钥对象 
 */  
public RSAPrivateKey getPrivateKey() {  
    return privateKey;  
}  

/** 
 * 获取公钥 
 * [@return](https://my.oschina.net/u/556800) 当前的公钥对象 
 */  
public RSAPublicKey getPublicKey() {  
    return publicKey;  
}  

/** 
 * 随机生成密钥对 
 */  
public void genKeyPair(){  
    KeyPairGenerator keyPairGen= null;  
    try {  
        keyPairGen= KeyPairGenerator.getInstance("RSA");  
    } catch (NoSuchAlgorithmException e) {  
        e.printStackTrace();  
    }  
    keyPairGen.initialize(1024, new SecureRandom());  
    KeyPair keyPair= keyPairGen.generateKeyPair();  
    this.privateKey= (RSAPrivateKey) keyPair.getPrivate();  
    this.publicKey= (RSAPublicKey) keyPair.getPublic();  
}  

/** 
 * 从文件中输入流中加载公钥 
 * [@param](https://my.oschina.net/u/2303379) in 公钥输入流 
 * @throws Exception 加载公钥时产生的异常 
 */  
public void loadPublicKey(InputStream in) throws Exception{  
    try {  
        BufferedReader br= new BufferedReader(new InputStreamReader(in));  
        String readLine= null;  
        StringBuilder sb= new StringBuilder();  
        while((readLine= br.readLine())!=null){  
            if(readLine.charAt(0)=='-'){  
                continue;  
            }else{  
                sb.append(readLine);  
                sb.append('\r');  
            }  
        }  
        loadPublicKey(sb.toString());  
    } catch (IOException e) {  
        throw new Exception("公钥数据流读取错误");  
    } catch (NullPointerException e) {  
        throw new Exception("公钥输入流为空");  
    }  
}  

/** 
 * 从字符串中加载公钥 
 * @param publicKeyStr 公钥数据字符串 
 * @throws Exception 加载公钥时产生的异常 
 */  

// public void loadPublicKey(String publicKeyStr) throws Exception{
// try {
// BASE64Decoder base64Decoder= new BASE64Decoder();
// byte[] buffer= base64Decoder.decodeBuffer(publicKeyStr); // KeyFactory keyFactory= KeyFactory.getInstance("RSA");
// X509EncodedKeySpec keySpec= new X509EncodedKeySpec(buffer);
// this.publicKey= (RSAPublicKey) keyFactory.generatePublic(keySpec);
// } catch (NoSuchAlgorithmException e) {
// throw new Exception("无此算法");
// } catch (InvalidKeySpecException e) {
// throw new Exception("公钥非法");
// } catch (IOException e) {
// throw new Exception("公钥数据内容读取错误");
// } catch (NullPointerException e) {
// throw new Exception("公钥数据为空");
// }
// }

/** 
 * 从字符串中加载公钥 
 * @param publicKeyStr 公钥数据字符串 
 * @throws Exception 加载公钥时产生的异常 
 */  
public void loadPublicKey(String publicKeyStr) throws Exception{  
    try {  
        BASE64Decoder base64Decoder= new BASE64Decoder();  
        byte[] buffer= base64Decoder.decodeBuffer(publicKeyStr);  
        KeyFactory keyFactory= KeyFactory.getInstance("RSA");  
        X509EncodedKeySpec keySpec= new X509EncodedKeySpec(buffer);  
        this.publicKey= (RSAPublicKey) keyFactory.generatePublic(keySpec);  
    } catch (NoSuchAlgorithmException e) {  
        throw new Exception("无此算法");  
    } catch (InvalidKeySpecException e) {  
        throw new Exception("公钥非法");  
    } catch (IOException e) {  
        throw new Exception("公钥数据内容读取错误");  
    } catch (NullPointerException e) {  
        throw new Exception("公钥数据为空");  
    }  
}  

/** 
 * 从文件中加载私钥 
 * @param keyFileName 私钥文件名 
 * @return 是否成功 
 * @throws Exception  
 */  
public void loadPrivateKey(InputStream in) throws Exception{  
    try {  
        BufferedReader br= new BufferedReader(new InputStreamReader(in));  
        String readLine= null;  
        StringBuilder sb= new StringBuilder();  
        while((readLine= br.readLine())!=null){  
            if(readLine.charAt(0)=='-'){  
                continue;  
            }else{  
                sb.append(readLine);  
                sb.append('\r');  
            }  
        }  
        loadPrivateKey(sb.toString());  
    } catch (IOException e) {  
        throw new Exception("私钥数据读取错误");  
    } catch (NullPointerException e) {  
        throw new Exception("私钥输入流为空");  
    }  
}  

public void loadPrivateKey(String privateKeyStr) throws Exception{  
    try {  
        BASE64Decoder base64Decoder= new BASE64Decoder();  
        byte[] buffer= base64Decoder.decodeBuffer(privateKeyStr);  
        PKCS8EncodedKeySpec keySpec= new PKCS8EncodedKeySpec(buffer);  
        KeyFactory keyFactory= KeyFactory.getInstance("RSA");  
        this.privateKey= (RSAPrivateKey) keyFactory.generatePrivate(keySpec);  
    } catch (NoSuchAlgorithmException e) {  
        throw new Exception("无此算法");  
    } catch (InvalidKeySpecException e) {  
        e.printStackTrace();
        throw new Exception("私钥非法");  
    } catch (IOException e) {  
        throw new Exception("私钥数据内容读取错误");  
    } catch (NullPointerException e) {  
        throw new Exception("私钥数据为空");  
    }  
}  

/** 
 * 加密过程 
 * @param publicKey 公钥 
 * @param plainTextData 明文数据 
 * @return 
 * @throws Exception 加密过程中的异常信息 
 */  
public byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData) throws Exception{  
    if(publicKey== null){  
        throw new Exception("加密公钥为空, 请设置");  
    }  
    Cipher cipher= null;  
    try {  
        cipher= Cipher.getInstance("RSA");//, new BouncyCastleProvider());  
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);  
        byte[] output= cipher.doFinal(plainTextData);  
        return output;  
    } catch (NoSuchAlgorithmException e) {  
        throw new Exception("无此加密算法");  
    } catch (NoSuchPaddingException e) {  
        e.printStackTrace();  
        return null;  
    }catch (InvalidKeyException e) {  
        throw new Exception("加密公钥非法,请检查");  
    } catch (IllegalBlockSizeException e) {  
        throw new Exception("明文长度非法");  
    } catch (BadPaddingException e) {  
        throw new Exception("明文数据已损坏");  
    }  
}  

/** 
 * 解密过程 
 * @param privateKey 私钥 
 * @param cipherData 密文数据 
 * @return 明文 
 * @throws Exception 解密过程中的异常信息 
 */  
public byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherData) throws Exception{  
    if (privateKey== null){  
        throw new Exception("解密私钥为空, 请设置");  
    }  
    Cipher cipher= null;  
    try {  
        cipher= Cipher.getInstance("RSA");//, new BouncyCastleProvider());  
        cipher.init(Cipher.DECRYPT_MODE, privateKey);  
        byte[] output= cipher.doFinal(cipherData);  
        return output;  
    } catch (NoSuchAlgorithmException e) {  
        throw new Exception("无此解密算法");  
    } catch (NoSuchPaddingException e) {  
        e.printStackTrace();  
        return null;  
    }catch (InvalidKeyException e) {  
        throw new Exception("解密私钥非法,请检查");  
    } catch (IllegalBlockSizeException e) {  
        throw new Exception("密文长度非法");  
    } catch (BadPaddingException e) {  
        throw new Exception("密文数据已损坏");  
    }         
}  



/** 
 * 字节数据转字符串专用集合 
 */  
private static final char[] HEX_CHAR= {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'}; 

/** 
 * 字节数据转十六进制字符串 
 * @param data 输入数据 
 * @return 十六进制内容 
 */  
public static String byteArrayToString(byte[] data){  
    StringBuilder stringBuilder= new StringBuilder();  
    for (int i=0; i<data.length; i++){  
        //取出字节的高四位 作为索引得到相应的十六进制标识符 注意无符号右移  
        stringBuilder.append(HEX_CHAR[(data[i] & 0xf0)>>> 4]);  
        //取出字节的低四位 作为索引得到相应的十六进制标识符  
        stringBuilder.append(HEX_CHAR[(data[i] & 0x0f)]);  
        if (i<data.length-1){  
            stringBuilder.append(' ');  
        }  
    }  
    return stringBuilder.toString();  
}  

} `