公司项目需要,聊天的时候不想明文传输,需要对话双方各有一个密钥,才能解开发送的密文信息!所以自然而然用到了DES加解密。但是问题随之而来了,我们后台是C#做的,客户端有我们Android和IOS,所以我们之间要相互都能解析才能沟通。所以、就是接下来的解决方法啦!
Android端加解密:
/**
* 加密
* @param message 原文
* @param key 密钥
* @return
* @throws Exception
*/
public static String EncryptAsDoNet(String message, String key)throws Exception {
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
byte[] encryptbyte = cipher.doFinal(message.getBytes());
return new String(Base64.encode(encryptbyte, Base64.DEFAULT));
}
/**
* 解密
* @param message 密文
* @param key 密钥
* @return
* @throws Exception
*/
public static String DecryptDoNet(String message, String key)throws Exception {
byte[] bytesrc = Base64.decode(message.getBytes(), Base64.DEFAULT);
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
byte[] retByte = cipher.doFinal(bytesrc);
return new String(retByte);
}
IOS端加解密:
static const char* encryptWithKeyAndType(const char *text,CCOperation encryptOperation,char *key)
{
NSString *textString=[[NSString alloc]initWithCString:text encoding:NSUTF8StringEncoding];
// NSLog(@"[[item.url description] UTF8String=%@",textString);
const void *dataIn;
size_t dataInLength;
if (encryptOperation == kCCDecrypt)//传递过来的是decrypt 解码
{
//解码 base64
NSData *decryptData = [GTMBase64 decodeData:[textString dataUsingEncoding:NSUTF8StringEncoding]];//转成utf-8并decode
dataInLength = [decryptData length];
dataIn = [decryptData bytes];
}
else //encrypt
{
NSData* encryptData = [textString dataUsingEncoding:NSUTF8StringEncoding];
dataInLength = [encryptData length];
dataIn = (const void *)[encryptData bytes];
}
CCCryptorStatus ccStatus;
uint8_t *dataOut = NULL; //可以理解位type/typedef 的缩写(有效的维护了代码,比如:一个人用int,一个人用long。最好用typedef来定义)
size_t dataOutAvailable = 0; //size_t 是操作符sizeof返回的结果类型
size_t dataOutMoved = 0;
dataOutAvailable = (dataInLength + kCCBlockSizeDES) & ~(kCCBlockSizeDES - 1);
dataOut = malloc( dataOutAvailable * sizeof(uint8_t));
memset((void *)dataOut, 00, dataOutAvailable);//将已开辟内存空间buffer的首 1 个字节的值设为值 0
//NSString *initIv = @"12345678";
const void *vkey = key;
const void *iv = (const void *) key; //[initIv UTF8String];
//CCCrypt函数 加密/解密
ccStatus = CCCrypt(encryptOperation,// 加密/解密
kCCAlgorithmDES,// 加密根据哪个标准(des,3des,aes。。。。)
kCCOptionPKCS7Padding,// 选项分组密码算法(des:对每块分组加一次密 3DES:对每块分组加三个不同的密)
vkey, //密钥 加密和解密的密钥必须一致
kCCKeySizeDES,// DES 密钥的大小(kCCKeySizeDES=8)
iv, // 可选的初始矢量
dataIn, // 数据的存储单元
dataInLength,// 数据的大小
(void *)dataOut,// 用于返回数据
dataOutAvailable,
&dataOutMoved);
NSString *result = nil;
if (encryptOperation == kCCDecrypt)//encryptOperation==1 解码
{
//得到解密出来的data数据,改变为utf-8的字符串
result = [[NSString alloc] initWithData:[NSData dataWithBytes:(const void *)dataOut length:(NSUInteger)dataOutMoved] encoding:NSUTF8StringEncoding];
}
else //encryptOperation==0 (加密过程中,把加好密的数据转成base64的)
{
//编码 base64
NSData *data = [NSData dataWithBytes:(const void *)dataOut length:(NSUInteger)dataOutMoved];
result = [GTMBase64 stringByEncodingData:data];
}
return [result UTF8String];
}
+(NSString*)encryptWithContent:(NSString*)content type:(CCOperation)type key:(NSString*)aKey
{
const char * contentChar =[content UTF8String];
char * keyChar =(char*)[aKey UTF8String];
const char *miChar;
miChar = encryptWithKeyAndType(contentChar, type, keyChar);
return [NSString stringWithCString:miChar encoding:NSUTF8StringEncoding];
}
C#端加解密:
#region 跨平台加解密(c# 安卓 IOS)
// public static string sKey = "12345678";
// ///
// /// 解密
// ///
// /// 要解密的以Base64
// /// 密钥,且必须为8位
// /// 已解密的字符串
// public static string DesDecrypt(string pToDecrypt)
// {
// //转义特殊字符
// pToDecrypt = pToDecrypt.Replace("-", "+");
// pToDecrypt = pToDecrypt.Replace("_", "/");
// pToDecrypt = pToDecrypt.Replace("~", "=");
// byte[] inputByteArray = Convert.FromBase64String(pToDecrypt);
// using (DESCryptoServiceProvider des = new DESCryptoServiceProvider())
// {
// des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
// des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
// System.IO.MemoryStream ms = new System.IO.MemoryStream();
// using (CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write))
// {
// cs.Write(inputByteArray, 0, inputByteArray.Length);
// cs.FlushFinalBlock();
// cs.Close();
// }
// string str = Encoding.UTF8.GetString(ms.ToArray());
// ms.Close();
// return str;
// }
// }
// ///
// /// 对字符串进行DES加密
// ///
// /// 待加密的字符串
// /// 加密后的BASE64编码的字符串
// public string Encrypt(string sourceString)
//{
// byte[] btKey = Encoding.UTF8.GetBytes(sKey);
// byte[] btIV = Encoding.UTF8.GetBytes(sKey);
// DESCryptoServiceProvider des = new DESCryptoServiceProvider();
// using (MemoryStream ms = new MemoryStream())
// {
// byte[] inData = Encoding.UTF8.GetBytes(sourceString);
// try
// {
// using (CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(btKey, btIV), CryptoStreamMode.Write))
// {
// cs.Write(inData, 0, inData.Length);
// cs.FlushFinalBlock();
// }
// return Convert.ToBase64String(ms.ToArray());
// }
// catch
// {
// throw;
// }
// }
//}
#endregion
参考资料:http://zhidao.baidu.com/link?url=ymdSUCnD9swHbPGdMTeMLmDW5crg7z6lv97J39wLbOrOozbibxg7vuUIKObKxRsZQ9t744yDH4PxbZYglURW8l159aAoOpm1gwnFl0GpqsG&qq-pf-to=pcqq.c2c
结合理解:http://www.cnblogs.com/whoislcj/p/5580950.html