AndroidiPhone和Java三个平台一致的加密工具

Posted 2022-12-03 沈成才

移动开发中遇到的最让人纠结的要属Java、android和iPhone三个平台加解密不一致的问题。因为手机端后台通常是用JAVA开发的Web Service，Android和iPhone客户端调用同样的Web Service接口，为了数据安全考虑，要对数据进行加密。头疼的问题就来了，很难编写出一套加密程序，在3个平台间加解密的结果一致，总不能为Android和iPhone两个客户端各写一套Web Service接口吧？我相信还会有很多朋友为此困惑，在此分享一套3DES加密程序，能够实现Java、Android和iPhone三个平台加解密一致。

    首先是JAVA端的加密工具类，它同样适用于Android端，无需任何修改，即可保证Java与Android端的加解密一致，并且中文不会乱码。 

package org.liuyq.des3;  

import java.security.Key;  

import javax.crypto.Cipher;  
import javax.crypto.SecretKeyFactory;  
import javax.crypto.spec.DESedeKeySpec;  
import javax.crypto.spec.IvParameterSpec;  

/** 
 * 3DES加密工具类 
 */  
public class Des3   
    // 密钥  
    private final static String secretKey = "liuyunqiang@lx100$#365#$";  
    // 向量  
    private final static String iv = "01234567";  
    // 加解密统一使用的编码方式  
    private final static String encoding = "utf-8";  

    /** 
     * 3DES加密 
     *  
     * @param plainText 普通文本 
     * @return 
     * @throws Exception  
     */  
    public static String encode(String plainText) throws Exception   
        Key deskey = null;  
        DESedeKeySpec spec = new DESedeKeySpec(secretKey.getBytes());  
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");  
        deskey = keyfactory.generateSecret(spec);  

        Cipher cipher = Cipher.getInstance("desede/CBC/PKCS5Padding");  
        IvParameterSpec ips = new IvParameterSpec(iv.getBytes());  
        cipher.init(Cipher.ENCRYPT_MODE, deskey, ips);  
        byte[] encryptData = cipher.doFinal(plainText.getBytes(encoding));  
        return Base64.encode(encryptData);  
      

    /** 
     * 3DES解密 
     *  
     * @param encryptText 加密文本 
     * @return 
     * @throws Exception 
     */  
    public static String decode(String encryptText) throws Exception   
        Key deskey = null;  
        DESedeKeySpec spec = new DESedeKeySpec(secretKey.getBytes());  
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");  
        deskey = keyfactory.generateSecret(spec);  
        Cipher cipher = Cipher.getInstance("desede/CBC/PKCS5Padding");  
        IvParameterSpec ips = new IvParameterSpec(iv.getBytes());  
        cipher.init(Cipher.DECRYPT_MODE, deskey, ips);  

        byte[] decryptData = cipher.doFinal(Base64.decode(encryptText));  

        return new String(decryptData, encoding);  
      
  

上面的加密工具类会使用到Base64这个类，该类的源代码如下：

import java.io.ByteArrayOutputStream;  
import java.io.IOException;  
import java.io.OutputStream;  

/** 
 * Base64编码工具类 
 */  
public class Base64   
    private static final char[] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();  

    public static String encode(byte[] data)   
        int start = 0;  
        int len = data.length;  
        StringBuffer buf = new StringBuffer(data.length * 3 / 2);  

        int end = len - 3;  
        int i = start;  
        int n = 0;  

        while (i <= end)   
            int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 0x0ff) << 8) | (((int) data[i + 2]) & 0x0ff);  

            buf.append(legalChars[(d >> 18) & 63]);  
            buf.append(legalChars[(d >> 12) & 63]);  
            buf.append(legalChars[(d >> 6) & 63]);  
            buf.append(legalChars[d & 63]);  

            i += 3;  

            if (n++ >= 14)   
                n = 0;  
                buf.append(" ");  
              
          

        if (i == start + len - 2)   
            int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 255) << 8);  

            buf.append(legalChars[(d >> 18) & 63]);  
            buf.append(legalChars[(d >> 12) & 63]);  
            buf.append(legalChars[(d >> 6) & 63]);  
            buf.append("=");  
         else if (i == start + len - 1)   
            int d = (((int) data[i]) & 0x0ff) << 16;  

            buf.append(legalChars[(d >> 18) & 63]);  
            buf.append(legalChars[(d >> 12) & 63]);  
            buf.append("==");  
          

        return buf.toString();  
      

    private static int decode(char c)   
        if (c >= 'A' && c <= 'Z')  
            return ((int) c) - 65;  
        else if (c >= 'a' && c <= 'z')  
            return ((int) c) - 97 + 26;  
        else if (c >= '0' && c <= '9')  
            return ((int) c) - 48 + 26 + 26;  
        else  
            switch (c)   
            case '+':  
                return 62;  
            case '/':  
                return 63;  
            case '=':  
                return 0;  
            default:  
                throw new RuntimeException("unexpected code: " + c);  
              
      

    /** 
     * Decodes the given Base64 encoded String to a new byte array. The byte array holding the decoded data is returned. 
     */  

    public static byte[] decode(String s)   

        ByteArrayOutputStream bos = new ByteArrayOutputStream();  
        try   
            decode(s, bos);  
         catch (IOException e)   
            throw new RuntimeException();  
          
        byte[] decodedBytes = bos.toByteArray();  
        try   
            bos.close();  
            bos = null;  
         catch (IOException ex)   
            System.err.println("Error while decoding BASE64: " + ex.toString());  
          
        return decodedBytes;  
      

    private static void decode(String s, OutputStream os) throws IOException   
        int i = 0;  

        int len = s.length();  

        while (true)   
            while (i < len && s.charAt(i) <= ' ')  
                i++;  

            if (i == len)  
                break;  

            int tri = (decode(s.charAt(i)) << 18) + (decode(s.charAt(i + 1)) << 12) + (decode(s.charAt(i + 2)) << 6) + (decode(s.charAt(i + 3)));  

            os.write((tri >> 16) & 255);  
            if (s.charAt(i + 2) == '=')  
                break;  
            os.write((tri >> 8) & 255);  
            if (s.charAt(i + 3) == '=')  
                break;  
            os.write(tri & 255);  

            i += 4;  
          
      

接下来是iPhone端的加密程序，当然是用Ojbective-C写的3DES加密程序，源代码如下：

//  
//  DES3Util.h  
//  

#import <Foundation/Foundation.h>  


@interface DES3Util : NSObject   

  

// 加密方法  
+ (NSString*)encrypt:(NSString*)plainText;  

// 解密方法  
+ (NSString*)decrypt:(NSString*)encryptText;  

@end  

//  
//  DES3Util.m  
//  

#import "DES3Util.h"  
#import <CommonCrypto/CommonCryptor.h>  
#import "GTMBase64.h"  

#define gkey            @"liuyunqiang@lx100$#365#$"  
#define gIv             @"01234567"  

@implementation DES3Util  

// 加密方法  
+ (NSString*)encrypt:(NSString*)plainText   
    NSData* data = [plainText dataUsingEncoding:NSUTF8StringEncoding];  
    size_t plainTextBufferSize = [data length];  
    const void *vplainText = (const void *)[data bytes];  

    CCCryptorStatus ccStatus;  
    uint8_t *bufferPtr = NULL;  
    size_t bufferPtrSize = 0;  
    size_t movedBytes = 0;  

    bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);  
    bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));  
    memset((void *)bufferPtr, 0x0, bufferPtrSize);  

    const void *vkey = (const void *) [gkey UTF8String];  
    const void *vinitVec = (const void *) [gIv UTF8String];  

    ccStatus = CCCrypt(kCCEncrypt,  
                       kCCAlgorithm3DES,  
                       kCCOptionPKCS7Padding,  
                       vkey,  
                       kCCKeySize3DES,  
                       vinitVec,  
                       vplainText,  
                       plainTextBufferSize,  
                       (void *)bufferPtr,  
                       bufferPtrSize,  
                       &movedBytes);  

    NSData *myData = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)movedBytes];  
    NSString *result = [GTMBase64 stringByEncodingData:myData];  
    return result;  
  

// 解密方法  
+ (NSString*)decrypt:(NSString*)encryptText   
    NSData *encryptData = [GTMBase64 decodeData:[encryptText dataUsingEncoding:NSUTF8StringEncoding]];  
    size_t plainTextBufferSize = [encryptData length];  
    const void *vplainText = [encryptData bytes];  

    CCCryptorStatus ccStatus;  
    uint8_t *bufferPtr = NULL;  
    size_t bufferPtrSize = 0;  
    size_t movedBytes = 0;  

    bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);  
    bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));  
    memset((void *)bufferPtr, 0x0, bufferPtrSize);  

    const void *vkey = (const void *) [gkey UTF8String];  
    const void *vinitVec = (const void *) [gIv UTF8String];  

    ccStatus = CCCrypt(kCCDecrypt,  
                       kCCAlgorithm3DES,  
                       kCCOptionPKCS7Padding,  
                       vkey,  
                       kCCKeySize3DES,  
                       vinitVec,  
                       vplainText,  
                       plainTextBufferSize,  
                       (void *)bufferPtr,  
                       bufferPtrSize,  
                       &movedBytes);  

    NSString *result = [[[NSString alloc] initWithData:[NSData dataWithBytes:(const void *)bufferPtr   
                                length:(NSUInteger)movedBytes] encoding:NSUTF8StringEncoding] autorelease];  
    return result;  
  

@end 

iPhone端的加密工具类中引入了“GTMBase64.h”，这是ios平台的Base64编码工具类，就不在这里贴出相关代码了，需要的百度一下就能找到。

    这样，JAVA，Android和iPhone三个平台的加密不一致问题就可以解决了。其实，对此问题，还有一种更好的实现方式，那就是用C语言写一套加密程序，这样在iOS平台是可以直接使用C程序的，而在Java和Android端通过JNI去调用C语言编写的加密方法，这样也可以实现3个平台调用同一套加密程序。

借鉴地址：http://blog.csdn.net/lyq8479/article/details/8062867