移動開發中遇到的最讓人糾結的要屬Java、Android和iPhone三個平臺加解密不一致的問題。由於手機端後臺一般是用JAVA開發的Web Service,Android和iPhone客戶端調用一樣的Web Service接口,爲了數據安全考慮,要對數據進行加密。頭疼的問題就來了,很難編寫出一套加密程序,在3個平臺間加解密的結果一致,總不能爲Android和iPhone兩個客戶端各寫一套Web Service接口吧?我相信還會有不少朋友爲此困惑,在此分享一套3DES加密程序,可以實現Java、Android和iPhone三個平臺加解密一致。
首先是JAVA端的加密工具類,它一樣適用於Android端,無需任何修改,便可保證Java與Android端的加解密一致,而且中文不會亂碼。
Java代碼java
package org.liuyq.des3;
安全
import java.security.Key;
app
import javax.crypto.Cipher;
工具
import javax.crypto.SecretKeyFactory;
ui
import javax.crypto.spec.DESedeKeySpec;
編碼
import javax.crypto.spec.IvParameterSpec;
加密
/**
spa
* 3DES加密工具類
.net
*/
code
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);
}
}
複製代碼
上面的加密工具類會使用到Base64這個類,該類的源代碼以下: Java代碼
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
* Base64編碼工具類
*/
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;
}
}
}
複製代碼
接下來是iPhone端的加密程序,固然是用Ojbective-C寫的3DES加密程序,源代碼以下:
Java代碼
//
// 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
複製代碼
Java代碼
//
// 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
複製代碼
iPhone端的加密工具類中引入了「GTMBase64.h」,這是iOS平臺的Base64編碼工具類,就不在這裏貼出相關代碼了,須要的百度一下就能找到。
這樣,JAVA,Android和iPhone三個平臺的加密不一致問題就能夠解決了。其實,對此問題,還有一種更好的實現方式,那就是用C語言寫一套加密程序,這樣在iOS平臺是能夠直接使用C程序的,而在Java和Android端經過JNI去調用C語言編寫的加密方法,這樣也能夠實現3個平臺調用同一套加密程序。