C++ 使用OpenSSL 基于SHA1摘要的RSA签名及验签 与Java平台互通

文章目录

  • 准备
  • C++
  • Java
        • RSASignature.java
        • RSAEncrypt.java
        • Base64.java

准备

配置OpenSSL环境
配置VS2015环境
生成公私秘钥
然后你们自己整吧,没时间弄,本来想弄成dll的,其实阿里的那个秘钥生成工具也不错,就是支付宝接入的那个sdk

C++

#pragma once
#include 
#include 
#include 
#include 
#include 
#include 
#define UNUSED(x) ((void)x)
#pragma comment(lib,"libssl.lib")
#pragma comment(lib,"libcrypto.lib")
typedef char byte;

std::string RSASign(std::string aSignContent,std::string aKeyPath) {
	try {
		BIO *bioPrivateKey = BIO_new(BIO_s_file());
		BIO_read_filename(bioPrivateKey, aKeyPath.c_str());
		RSA *rsaPrivateKey = PEM_read_bio_RSAPrivateKey(bioPrivateKey, NULL, NULL, NULL);
		BIO_free_all(bioPrivateKey);
		if (rsaPrivateKey == NULL) {
			return "";
		}
		char szTmp[10240], szTmp1[10240];
		const char* szEnData = aSignContent.c_str();
		int  flen, ienLen;
		unsigned int iRet;
		flen = strlen(szEnData);
		memset(szTmp, 0, sizeof(szTmp));
		memset(szTmp1, 0, sizeof(szTmp1));
		SHA1((unsigned char *)szEnData, flen, (unsigned char *)szTmp);
		ienLen = RSA_sign(NID_sha1, (unsigned char *)szTmp, 20, (unsigned char*)szTmp1, &iRet, rsaPrivateKey);
		if (ienLen != 1)
		{
			return "";
		}
		//return Base64_Encode(std::string(szTmp1, iRet));
		return std::string(szTmp1, iRet);
	}
	catch(std::exception e){
		return "";
	}
}

int RSACheckSign(std::string aContent, std::string aSignStr, std::string aKeyPath) {
	try {
		FILE *fp = fopen(aKeyPath.c_str(), "r");
		RSA * rsaPublicKey = PEM_read_RSA_PUBKEY(fp, NULL, NULL, NULL);
		if (rsaPublicKey == NULL) {
			return -100;
		}
		char szTmp[10240];
		int iRet = aContent.length();
		SHA1((unsigned char *)aContent.c_str(), iRet, (unsigned char *)szTmp);
		return RSA_verify(NID_sha1, (unsigned char *)szTmp, 20, (unsigned char*)aSignStr.c_str(), aSignStr.length(), rsaPublicKey);//==1
	}
	catch (std::exception e) {
		return -50;
	}
}

int main() {
	OpenSSL_add_all_algorithms();
}

Java

除Main函数外均为转载原文:https://blog.csdn.net/wangqiuyun/article/details/42143957/
Main.java

        String prik="MIICeAIBADANBgkqhkiG9w0BAQEFAASCAmIwggJeAgEAAoGBAKhJamQ3VUtPDDbW9De7iiDtl6k1WJxJTPTDIvAD4gny4VpB+og6OTNW+ttgN2qRjrXFQRzVDVtOFS64eshSxNDgAI1k2WRV5AtbZL5iCZ2d1NCodEDZHjbGt70MPttJPGZJ+9sMH7JjmWNk0D63297QwCSMiHzacvazsICoZPaPAgMBAAECgYAKFsSrF2okpquLyh1ADh081iGmgk06qWZUsjIxA3qUsBv0hkoXyq3NNyS47C7GU82jdhzuNpOjaq34bBToV5X2+uM1YaMWp3iSPO0hG9RkTCuJxyIYC1XMNia1ZC6AMO2KvnoueootCeLStIoI535qSz65P8XWv8y35DybNQhhgQJBANJiDuTLdS7asTnPN5CpCcLaO7bA0s+NRdzNSwXGfWyOiCJbO90k6SDv5pQ+NDZ43iFnUrl1ebh/gS1k4OqWJc8CQQDMxq2eUlReiQM+wBJSGAzQf9SO7pSVAu3rfBmdceRRMkmIEF49mOIlanFS1dcP/lmD85luiDHfl1kN2oxp2RNBAkEAgIFS9Z/tSRxeCqCvIRaPlsy0ktG/MvXpCZEAVVvDuu5o6wttSoxENlEzN7OzMt6rWB4DorLGEdMYNYEb/U6PcwJBAIgsMnZO71XyLNtEpKo83gCkkPf/hYTV7tsiqnH9s8Oe+jDmGZVCnlgdQYDBPQOgs2xAyK4tGWVDYvAIfklBFkECQQCHzCn22iCcH/RGt3eGmFDJMLfW9MetySoBKTTTAa5NofqW7U3kblGeIzqap6BsM/NyYZO6jhienEQ5fy4UgJ+p";
    	String pubk="MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCoSWpkN1VLTww21vQ3u4og7ZepNVicSUz0wyLwA+IJ8uFaQfqIOjkzVvrbYDdqkY61xUEc1Q1bThUuuHrIUsTQ4ACNZNlkVeQLW2S+YgmdndTQqHRA2R42xre9DD7bSTxmSfvbDB+yY5ljZNA+t9ve0MAkjIh82nL2s7CAqGT2jwIDAQAB";
    	String SN="Now is the time for all good men to come to the aide of their country";
    	String SNK="31E922D1AFF343151D18AF1DEC8B64EB57076263D6888B8C75E22DD3E1D297316360CB546B48FDD24B45CAA19EDC9F156480F5624167DA12831518AA03620ACEAA2C5F1E6F53BE4C3BCD89937501CCC3409B4AC04F0FEF4F6A4A9BE117E57" + 
    			"3D80301032F686DA403D64FE031E7E0ECC055D87D5A366933C4EEDE5F5F475F9DB8";
    	String SNKK="GLGBiW68V+ie7k7U1hwZrtO63fz3N/a6QQEYoii3X6lAIqV5JMIBzsNtqWRCCFvkkvSbcJSesurzOVgGBD6Sd+9Voei9t3+jJasA/n5GRYlOAtj7PKXqAfijYa4sY7Gh561bprQZQlbk4U3zhp3U+yeLVcU2V6s73Gi9M2qKdQg=";
    	
    	String signstr=RSASignature.sign(SN,prik);
    	System.out.println(signstr);
    	System.out.println();
    	byte[]snk=Base64.decode(signstr);
    	try {System.out.println("验签结果:"+RSASignature.doCheck(SN, signstr, pubk));}catch(Exception e) {System.out.println("Error:"+e.toString());}
    	System.out.println(snk.length);
    	System.out.println();
    	for(int i=0;i

RSASignature.java

import java.math.BigInteger;
import java.security.KeyFactory;  
import java.security.PrivateKey;  
import java.security.PublicKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.RSAPublicKeySpec;
import java.security.spec.X509EncodedKeySpec;  
   
/** 
 * RSA签名验签类 
 */  
public class RSASignature{  
       
    /** 
     * 签名算法 
     */  
    public static final String SIGN_ALGORITHMS = "SHA1WithRSA";  
   
    /** 
    * RSA签名 
    * @param content 待签名数据 
    * @param privateKey 商户私钥 
    * @param encode 字符集编码 
    * @return 签名值 
    */  
    public static String sign(String content, String privateKey, String encode)  
    {  
        try   
        {  
            PKCS8EncodedKeySpec priPKCS8    = new PKCS8EncodedKeySpec( Base64.decode(privateKey) );   
               
            KeyFactory keyf                 = KeyFactory.getInstance("RSA");  
            PrivateKey priKey               = keyf.generatePrivate(priPKCS8);  
   
            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);  
   
            signature.initSign(priKey);  
            signature.update( content.getBytes(encode));  
            byte[] signed = signature.sign();  
               
            return Base64.encode(signed);  
        }  
        catch (Exception e)   
        {  
            e.printStackTrace();  
        }  
           
        return null;  
    }  
       
    public static String sign(String content, String privateKey)  
    {  
        try   
        {  
            PKCS8EncodedKeySpec priPKCS8    = new PKCS8EncodedKeySpec( Base64.decode(privateKey) );   
            KeyFactory keyf = KeyFactory.getInstance("RSA");  
            PrivateKey priKey = keyf.generatePrivate(priPKCS8);  
            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);  //SIGN_ALGORITHMS
            signature.initSign(priKey);  
            signature.update( content.getBytes());  
            byte[] signed = signature.sign();  
            return Base64.encode(signed);  
        }  
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return null;
    }
       
    /** 
    * RSA验签名检查 
    * @param content 待签名数据 
    * @param sign 签名值 
    * @param publicKey 分配给开发商公钥 
    * @param encode 字符集编码 
    * @return 布尔值 
    */  
    public static boolean doCheck(String content, String sign, String publicKey,String encode)  
    {  
        try
        {  
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");  
            byte[] encodedKey = Base64.decode(publicKey);  
            PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));  
   
            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);
            signature.initVerify(pubKey);  
            signature.update( content.getBytes(encode) );  
           
            return signature.verify( Base64.decode(sign) );  
               
        }   
        catch (Exception e)   
        {  
            e.printStackTrace();  
        }  
           
        return false;
    }  
    public static boolean doCheck(String content,String sign,String Mod,String Exp,String fmt) {
    	try   
        {  
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        	RSAPublicKeySpec keySpec=new RSAPublicKeySpec(new BigInteger(Mod.getBytes()),new BigInteger(Exp.getBytes()));
        	RSAPublicKey pubKey = (RSAPublicKey) keyFactory.generatePublic(keySpec);
            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);
            signature.initVerify(pubKey);
            signature.update(content.getBytes("utf-8"));
            return signature.verify(Base64.decode(sign));
        }
        catch (Exception e) {}
		return false;
    }
    public static boolean doCheck(String content, String sign, String publicKey)  
    {  
        try   
        {  
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");  
            byte[] encodedKey = Base64.decode(publicKey);  
            PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));
            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);
            signature.initVerify(pubKey);  
            signature.update( content.getBytes("utf-8") );  
            return signature.verify( Base64.decode(sign) );
               
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
           
        return false;  
    }  
       
}

RSAEncrypt.java

import java.io.BufferedReader;  
import java.io.BufferedWriter;  
import java.io.FileReader;  
import java.io.FileWriter;  
import java.io.IOException;  
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;  
   
public class RSAEncrypt {  
    /** 
     * 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' };  
   
    /** 
     * 随机生成密钥对 
     */  
    public static void genKeyPair(String filePath) {  
        // KeyPairGenerator类用于生成公钥和私钥对,基于RSA算法生成对象  
        KeyPairGenerator keyPairGen = null;  
        try {  
            keyPairGen = KeyPairGenerator.getInstance("RSA");  
        } catch (NoSuchAlgorithmException e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
        }  
        // 初始化密钥对生成器,密钥大小为96-1024位  
        SecureRandom random = new SecureRandom();
        random.setSeed(random.generateSeed(1024));
        keyPairGen.initialize(1024,random);  
        // 生成一个密钥对,保存在keyPair中  
        KeyPair keyPair = keyPairGen.generateKeyPair();
        System.out.println(keyPairGen.generateKeyPair().equals(keyPairGen.generateKeyPair()));
        // 得到私钥  
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        // 得到公钥  
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        try {  
            // 得到公钥字符串  
            String publicKeyString = Base64.encode(publicKey.getEncoded());  
            // 得到私钥字符串  
            String privateKeyString = Base64.encode(privateKey.getEncoded());  
            // 将密钥对写入到文件  
            FileWriter pubfw = new FileWriter(filePath + "/publicKey.keystore");  
            FileWriter prifw = new FileWriter(filePath + "/privateKey.keystore");  
            BufferedWriter pubbw = new BufferedWriter(pubfw);  
            BufferedWriter pribw = new BufferedWriter(prifw);  
            pubbw.write(publicKeyString);  
            pribw.write(privateKeyString);  
            pubbw.flush();  
            pubbw.close();  
            pubfw.close();  
            pribw.flush();  
            pribw.close();  
            prifw.close();  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
   
    /** 
     * 从文件中输入流中加载公钥 
     *  
     * @param in 
     *            公钥输入流 
     * @throws Exception 
     *             加载公钥时产生的异常 
     */  
    public static String loadPublicKeyByFile(String path) throws Exception {  
        try {  
            BufferedReader br = new BufferedReader(new FileReader(path  
                    + "/publicKey.keystore"));  
            String readLine = null;  
            StringBuilder sb = new StringBuilder();  
            while ((readLine = br.readLine()) != null) {  
                sb.append(readLine);  
            }  
            br.close();  
            return 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 static RSAPublicKey loadPublicKeyByStr(String publicKeyStr)  
            throws Exception {  
        try {  
            byte[] buffer = Base64.decode(publicKeyStr);  
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");  
            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);  
            return (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 (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 static String loadPrivateKeyByFile(String path) throws Exception {  
        try {  
            BufferedReader br = new BufferedReader(new FileReader(path  
                    + "/privateKey.keystore"));  
            String readLine = null;  
            StringBuilder sb = new StringBuilder();  
            while ((readLine = br.readLine()) != null) {  
                sb.append(readLine);  
            }  
            br.close();  
            return 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 static RSAPrivateKey loadPrivateKeyByStr(String privateKeyStr)  
            throws Exception {  
        try {  
            byte[] buffer = Base64.decode(privateKeyStr);  
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);  
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");  
            return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);  
        } catch (NoSuchAlgorithmException e) {  
            throw new Exception("无此算法");  
        } catch (InvalidKeySpecException e) {  
            throw new Exception("私钥非法");  
        } catch (NullPointerException e) {  
            throw new Exception("私钥数据为空");  
        }  
    }  
   
    /** 
     * 公钥加密过程 
     *  
     * @param publicKey 
     *            公钥 
     * @param plainTextData 
     *            明文数据 
     * @return 
     * @throws Exception 
     *             加密过程中的异常信息 
     */  
    public static 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 {  
            // 使用默认RSA  
            cipher = Cipher.getInstance("RSA");  
            // 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");  
        }  
    }  
   
    /** 
     * 私钥加密过程 
     *  
     * @param privateKey 
     *            私钥 
     * @param plainTextData 
     *            明文数据 
     * @return 
     * @throws Exception 
     *             加密过程中的异常信息 
     */  
    public static byte[] encrypt(RSAPrivateKey privateKey, byte[] plainTextData)  
            throws Exception {  
        if (privateKey == null) {  
            throw new Exception("加密私钥为空, 请设置");  
        }  
        Cipher cipher = null;  
        try {  
            // 使用默认RSA  
            cipher = Cipher.getInstance("RSA");  
            cipher.init(Cipher.ENCRYPT_MODE, privateKey);  
            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("加密私钥非法,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");  
        }  
    }  
   
    /** 
     * 私钥解密过程 
     *  
     * @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 static 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 {  
            // 使用默认RSA  
            cipher = Cipher.getInstance("RSA");  
            // 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");  
        }  
    }  
   
    /** 
     * 公钥解密过程 
     *  
     * @param publicKey 
     *            公钥 
     * @param cipherData 
     *            密文数据 
     * @return 明文 
     * @throws Exception 
     *             解密过程中的异常信息 
     */  
    public static byte[] decrypt(RSAPublicKey publicKey, byte[] cipherData)  
            throws Exception {  
        if (publicKey == null) {  
            throw new Exception("解密公钥为空, 请设置");  
        }  
        Cipher cipher = null;  
        try {  
            // 使用默认RSA  
            cipher = Cipher.getInstance("RSA");  
            // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());  
            cipher.init(Cipher.DECRYPT_MODE, publicKey);  
            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("解密公钥非法,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();  
    }  
}

Base64.java

public final class Base64 {  
   
    static private final int     BASELENGTH           = 128;  
    static private final int     LOOKUPLENGTH         = 64;  
    static private final int     TWENTYFOURBITGROUP   = 24;  
    static private final int     EIGHTBIT             = 8;  
    static private final int     SIXTEENBIT           = 16;  
    static private final int     FOURBYTE             = 4;  
    static private final int     SIGN                 = -128;  
    static private final char    PAD                  = '=';  
    static private final boolean fDebug               = false;  
    static final private byte[]  base64Alphabet       = new byte[BASELENGTH];  
    static final private char[]  lookUpBase64Alphabet = new char[LOOKUPLENGTH];  
   
    static {  
        for (int i = 0; i < BASELENGTH; ++i) {  //128
            base64Alphabet[i] = -1;  
        }  
        for (int i = 'Z'; i >= 'A'; i--) {  
            base64Alphabet[i] = (byte) (i - 'A');  
        }  
        for (int i = 'z'; i >= 'a'; i--) {  
            base64Alphabet[i] = (byte) (i - 'a' + 26);  
        }  
   
        for (int i = '9'; i >= '0'; i--) {  
            base64Alphabet[i] = (byte) (i - '0' + 52);  
        }  
   
        base64Alphabet['+'] = 62;  
        base64Alphabet['/'] = 63;  
   
        for (int i = 0; i <= 25; i++) {  
            lookUpBase64Alphabet[i] = (char) ('A' + i);  
        }  
   
        for (int i = 26, j = 0; i <= 51; i++, j++) {  
            lookUpBase64Alphabet[i] = (char) ('a' + j);  
        }  
   
        for (int i = 52, j = 0; i <= 61; i++, j++) {  
            lookUpBase64Alphabet[i] = (char) ('0' + j);  
        }  
        lookUpBase64Alphabet[62] = (char) '+';  
        lookUpBase64Alphabet[63] = (char) '/'; 
    }  
   
    private static boolean isWhiteSpace(char octect) {  
        return (octect == 0x20 || octect == 0xd || octect == 0xa || octect == 0x9);  
    }  
   
    private static boolean isPad(char octect) {  
        return (octect == PAD);  
    }  
   
    private static boolean isData(char octect) {  
        return (octect < BASELENGTH && base64Alphabet[octect] != -1);  
    }  
   
    /** 
     * Encodes hex octects into Base64 
     * 
     * @param binaryData Array containing binaryData 
     * @return Encoded Base64 array 
     */  
    public static String encode(byte[] binaryData) {  
   
        if (binaryData == null) {  
            return null;  
        }  
   
        int lengthDataBits = binaryData.length * EIGHTBIT;  
        if (lengthDataBits == 0) {  
            return "";  
        }  
   
        int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;  
        int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;  
        int numberQuartet = fewerThan24bits != 0 ? numberTriplets + 1 : numberTriplets;  
        char encodedData[] = null;  
   
        encodedData = new char[numberQuartet * 4];  
   
        byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;  
   
        int encodedIndex = 0;
        int dataIndex = 0;  
        if (fDebug) {
            System.out.println("number of triplets = " + numberTriplets);  
        }
   
        for (int i = 0; i < numberTriplets; i++) {  
            b1 = binaryData[dataIndex++];  
            b2 = binaryData[dataIndex++];  
            b3 = binaryData[dataIndex++];  
   
            if (fDebug) {  
                System.out.println("b1= " + b1 + ", b2= " + b2 + ", b3= " + b3);  
            }  
   
            l = (byte) (b2 & 0x0f);  
            k = (byte) (b1 & 0x03);  
   
            byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);  
            byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);  
            byte val3 = ((b3 & SIGN) == 0) ? (byte) (b3 >> 6) : (byte) ((b3) >> 6 ^ 0xfc);  
            
   
            if (fDebug) {  
                System.out.println("val2 = " + val2);  
                System.out.println("k4   = " + (k << 4));  
                System.out.println("vak  = " + (val2 | (k << 4)));  
            }  
   
            encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];  
            encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];  
            encodedData[encodedIndex++] = lookUpBase64Alphabet[(l << 2) | val3];  
            encodedData[encodedIndex++] = lookUpBase64Alphabet[b3 & 0x3f];  
        }  
   
        // form integral number of 6-bit groups  
        if (fewerThan24bits == EIGHTBIT) {  
            b1 = binaryData[dataIndex];  
            k = (byte) (b1 & 0x03);  
            if (fDebug) {  
                System.out.println("b1=" + b1);  
                System.out.println("b1<<2 = " + (b1 >> 2));  
            }  
            byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);  
            encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];  
            encodedData[encodedIndex++] = lookUpBase64Alphabet[k << 4];  
            encodedData[encodedIndex++] = PAD;  
            encodedData[encodedIndex++] = PAD;  
        } else if (fewerThan24bits == SIXTEENBIT) {  
            b1 = binaryData[dataIndex];  
            b2 = binaryData[dataIndex + 1];  
            l = (byte) (b2 & 0x0f);  
            k = (byte) (b1 & 0x03);  
   
            byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);  
            byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);  
   
            encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];  
            encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];  
            encodedData[encodedIndex++] = lookUpBase64Alphabet[l << 2];  
            encodedData[encodedIndex++] = PAD;  
        }  
   
        return new String(encodedData);  
    }  
   
    /** 
     * Decodes Base64 data into octects 
     * 
     * @param encoded string containing Base64 data 
     * @return Array containind decoded data. 
     */  
    public static byte[] decode(String encoded) {  
   
        if (encoded == null) {  
            return null;  
        }  
   
        char[] base64Data = encoded.toCharArray();  
        // remove white spaces  
        int len = removeWhiteSpace(base64Data);  
   
        if (len % FOURBYTE != 0) {  
            return null;//should be divisible by four  
        }  
   
        int numberQuadruple = (len / FOURBYTE);  
   
        if (numberQuadruple == 0) {  
            return new byte[0];  
        }  
   
        byte decodedData[] = null;  
        byte b1 = 0, b2 = 0, b3 = 0, b4 = 0;  
        char d1 = 0, d2 = 0, d3 = 0, d4 = 0;  
   
        int i = 0;  
        int encodedIndex = 0;  
        int dataIndex = 0;  
        decodedData = new byte[(numberQuadruple) * 3];  
   
        for (; i < numberQuadruple - 1; i++) {  
   
            if (!isData((d1 = base64Data[dataIndex++])) || !isData((d2 = base64Data[dataIndex++]))  
                || !isData((d3 = base64Data[dataIndex++]))  
                || !isData((d4 = base64Data[dataIndex++]))) {  
                return null;  
            }//if found "no data" just return null  
   
            b1 = base64Alphabet[d1];  
            b2 = base64Alphabet[d2];  
            b3 = base64Alphabet[d3];  
            b4 = base64Alphabet[d4];  
   
            decodedData[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);  
            decodedData[encodedIndex++] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));  
            decodedData[encodedIndex++] = (byte) (b3 << 6 | b4);  
        }  
   
        if (!isData((d1 = base64Data[dataIndex++])) || !isData((d2 = base64Data[dataIndex++]))) {  
            return null;//if found "no data" just return null  
        }  
   
        b1 = base64Alphabet[d1];  
        b2 = base64Alphabet[d2];  
   
        d3 = base64Data[dataIndex++];  
        d4 = base64Data[dataIndex++];  
        if (!isData((d3)) || !isData((d4))) {//Check if they are PAD characters  
            if (isPad(d3) && isPad(d4)) {  
                if ((b2 & 0xf) != 0)//last 4 bits should be zero  
                {  
                    return null;  
                }  
                byte[] tmp = new byte[i * 3 + 1];  
                System.arraycopy(decodedData, 0, tmp, 0, i * 3);  
                tmp[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);  
                return tmp;  
            } else if (!isPad(d3) && isPad(d4)) {  
                b3 = base64Alphabet[d3];  
                if ((b3 & 0x3) != 0)//last 2 bits should be zero  
                {  
                    return null;  
                }  
                byte[] tmp = new byte[i * 3 + 2];  
                System.arraycopy(decodedData, 0, tmp, 0, i * 3);  
                tmp[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);  
                tmp[encodedIndex] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));  
                return tmp;  
            } else {  
                return null;  
            }  
        } else { //No PAD e.g 3cQl  
            b3 = base64Alphabet[d3];  
            b4 = base64Alphabet[d4];  
            decodedData[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);  
            decodedData[encodedIndex++] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));  
            decodedData[encodedIndex++] = (byte) (b3 << 6 | b4);  
   
        }  
   
        return decodedData;  
    }  
   
    /** 
     * remove WhiteSpace from MIME containing encoded Base64 data. 
     * 
     * @param data  the byte array of base64 data (with WS) 
     * @return      the new length 
     */  
    private static int removeWhiteSpace(char[] data) {  
        if (data == null) {  
            return 0;  
        }  
   
        // count characters that's not whitespace  
        int newSize = 0;  
        int len = data.length;  
        for (int i = 0; i < len; i++) {  
            if (!isWhiteSpace(data[i])) {  
                data[newSize++] = data[i];  
            }  
        }  
        return newSize;  
    }  
}

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