[022] Android、iPhone和Java三個平台一致的加密工具__android

        先前一直在做安卓，最近要開發iPhone用戶端，這其中遇到的最讓人糾結的要屬Java、Android和iPhone三個平台加解密不一致的問題。因為手機端後台通常是用JAVA開發的Web Service，Android和iPhone用戶端調用同樣的Web Service介面，為了資料安全考慮，要對資料進行加密。頭疼的問題就來了，很難編寫出一套加密程式，在3個平台間加解密的結果一致，總不能為Android和iPhone兩個用戶端各寫一套Web Service介面吧。我相信還會有很多朋友為此困惑，在此分享一套3DES加密程式，能夠實現Java、Android和iPhone三個平台加解密一致。

        首先是JAVA端的加密工具類，它同樣適用於Android端，無需任何修改，即可保證Java與Android端的加解密一致，並且中文不會亂碼。

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加密工具類 *  * @author liufeng  * @date 2012-10-11 */public class Des3 {// 密鑰private final static String secretKey = "liuyunqiang@lx100$#365#$";// 向量private final static String iv = "01234567";// 加解密統一使用的編碼方式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);}}

        上面的加密工具類會使用到Base64這個類，該類的原始碼如下：

package org.liuyq.des3;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.OutputStream;/** * Base64編碼工具類 *  * @author liufeng  * @date 2012-10-11 */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;elseswitch (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;}}}

        接下來是iPhone端的加密程式，當然是用Ojbective-C寫的3DES加密程式，原始碼如下：

////  DES3Util.h//  lx100-gz////  Created by  柳峰 on 12-10-10.//  Copyright 2012 http://blog.csdn.net/lyq8479. All rights reserved.//#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//  lx100-gz////  Created by  柳峰 on 12-9-17.//  Copyright 2012 http://blog.csdn.net/lyq8479. All rights reserved.//#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端的加密工具類中引入了“GTMBase64.h”，這是iOS平台的Base64編碼工具類，就不在這裡貼出相關代碼了，需要的百度一下就能找到，實在找不到就回複留言給我。

        好了，趕緊試一下吧，JAVA，Android和iPhone三個平台的加密不一致問題是不是解決了呢。其實，對此問題，還有一種更好的實現方式，那就是用C語言寫一套加密程式，這樣在iOS平台是可以直接使用C程式的，而在Java和Android端通過JNI去調用C語言編寫的加密方法，這是不是就實現了3個平台叫用同一套加密程式呢。