原文:

公司在做移动端ios/android，服务器提供接口使用的.net，用到加密解密这一块，也在网上找了一些方法，有些是.net加密了android解密不了，或者反之。下面的是三个平台都可以加密解密的方法。加密解密中用到的key="1234578";在调取方法时传值即可。

C#代码

　　　　 #region   跨平台加解密（c#）                /// 
        /// 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, string sKey)        {            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;                }            }        }        /// 
        /// 解密        /// 
        /// 要解密的以Base64        /// 密钥，且必须为8位        /// 
        
         已解密的字符串
                public string Decrypt(string pToDecrypt, string sKey)        {            //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;            }        }        #endregion

IOS代码

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decrypt 解码    {        //解码 base64        NSData *decryptData = [GTMBase64 decodeData:[textString dataUsingEncoding:NSUTF8StringEncoding]];//转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; //理解位type/typedef 缩写（效维护代码比：用int用long用typedef定义）    size_t dataOutAvailable = 0; //size_t  操作符sizeof返结类型    size_t dataOutMoved = 0;        dataOutAvailable = (dataInLength + kCCBlockSizeDES) & ~(kCCBlockSizeDES - 1);    dataOut = malloc( dataOutAvailable * sizeof(uint8_t));    memset((void *)dataOut, 00, dataOutAvailable);//已辟内存空间buffer首 1 字节值设值 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,//  加密根据哪标准（des3desaes）                       kCCOptionPKCS7Padding,//  选项组密码算(des:每块组加密  3DES：每块组加三同密)                       vkey,  //密钥    加密解密密钥必须致                       kCCKeySizeDES,//   DES 密钥（kCCKeySizeDES=8）                       iv, //  选初始矢量                       dataIn, // 数据存储单元                       dataInLength,// 数据                       (void *)dataOut,// 用于返数据                       dataOutAvailable,                       &dataOutMoved);        NSString *result = nil;        if (encryptOperation == kCCDecrypt)//encryptOperation==1  解码    {        //解密data数据改变utf-8字符串        result = [[NSString alloc] initWithData:[NSData dataWithBytes:(const void *)dataOut length:(NSUInteger)dataOutMoved] encoding:NSUTF8StringEncoding];    }    else //encryptOperation==0  （加密程加密数据转base64）    {        //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];}

Android代码

//加密        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);        }        // 解密        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));        }

 　　最后还要注意一下，一般在客户端调用接口时，请求的是URL地址，参数需要加密，比如token，如果token里含有+号，URL会转码为空格，这时在.net端接收到token时，需要把token中的空格替换为+号：token = Regex.Replace(token, @"\s", "+");这样接收到的token才能正常的解密。