用iOS加密;用.net解密

我需要在iPhone或iPad上加密字符串(实际上是XML文件)，然后用。net应用程序解密它。感谢David Veksler的问题，.Net和iPhone之间的AES互操作性?，和博客文章在这里，http://automagical.rationalmind.net/2009/02/12/aes-interoperability-between-net-and-iphone/，我想我是相当接近完成这个。

但是在c#方法返回的解密字符串(XML)中，前16个字符是乱码。从第17个字符开始，解密的字符串与objective-c方法加密的字符串匹配。

我尽可能严格地遵循David的代码，但可能在一些尝试和错误之后改变了一些东西。这里是加密代码(密码和initVector只是硬编码在那里现在):

    CCCryptorStatus result = CCCryptorCreate(kCCEncrypt,
                                         kCCAlgorithmAES128,
                                         kCCOptionPKCS7Padding, // 0x0000 or kCCOptionPKCS7Padding
                                         (const void *)[@"1234567891123456" dataUsingEncoding:NSUTF8StringEncoding].bytes,
                                         [@"1234567891123456" dataUsingEncoding:NSUTF8StringEncoding].length,
                                         (const void *)[@"0000000000000000" dataUsingEncoding:NSUTF8StringEncoding].bytes,
                                         &thisEncipher
                                         );
    uint8_t *bufferPtr = NULL;
    size_t bufferPtrSize = 0;
    size_t remainingBytes = 0;
    size_t movedBytes = 0;
    size_t plainTextBufferSize = 0;
    size_t totalBytesWritten = 0;
    uint8_t *ptr;
    NSData *plainText = [xmlFileText dataUsingEncoding:NSASCIIStringEncoding];
    plainTextBufferSize = [plainText length];
    bufferPtrSize = CCCryptorGetOutputLength(thisEncipher, plainTextBufferSize, true);
    bufferPtr = malloc(bufferPtrSize * sizeof(uint8_t));
    memset((void *)bufferPtr, 0x0, bufferPtrSize);
    ptr = bufferPtr;
    remainingBytes = bufferPtrSize;
    result = CCCryptorUpdate(thisEncipher,
                         (const void *)[plainText bytes],
                         plainTextBufferSize,
                         ptr,
                         remainingBytes,
                         &movedBytes
                         );
    ptr += movedBytes;
    remainingBytes -= movedBytes;
    totalBytesWritten += movedBytes;
    result = CCCryptorFinal(thisEncipher,
                        ptr,
                        remainingBytes,
                        &movedBytes
                        );
    totalBytesWritten += movedBytes;
    if (thisEncipher)
    {
        (void) CCCryptorRelease(thisEncipher);
        thisEncipher = NULL;
    }
    if (result == kCCSuccess)
    {
        NSData *encryptedData = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)totalBytesWritten];
        [[encryptedData base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithCarriageReturn] writeToFile:docFile atomically:NO encoding:NSUTF8StringEncoding error:nil];
        NSLog(@"%d:%d:%d:%@:%@", xmlFileText.length,
                                 encryptedData.length,
                                 [encryptedData base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithCarriageReturn].length,
                                 encryptedData,
                                 [encryptedData base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithCarriageReturn]);
        if (bufferPtr)
            free(bufferPtr);
        return;
}

下面是解密代码:

    public static string DecryptString(string base64StringToDecrypt, string passphrase)
    {
        //Set up the encryption objects
        using (AesCryptoServiceProvider acsp = GetProvider(Encoding.Default.GetBytes(passphrase)))
        {   
            byte[] RawBytes = Convert.FromBase64String(base64StringToDecrypt);
            ICryptoTransform ictD = acsp.CreateDecryptor();
            //RawBytes now contains original byte array, still in Encrypted state
            //Decrypt into stream
            MemoryStream msD = new MemoryStream(RawBytes, 0, RawBytes.Length);
            CryptoStream csD = new CryptoStream(msD, ictD, CryptoStreamMode.Read);
            //csD now contains original byte array, fully decrypted
            //return the content of msD as a regular string
            return (new StreamReader(csD)).ReadToEnd();
        }
    }

从现场比较几个，它似乎NSData, encryptedData包含相同的值作为byte[], RawBytes。但是在StreamReader.ReadToEnd()之后返回的XML字符串与NSString、xmlFileText匹配，除了前16个字符。我怀疑问题是我加密获得NSData *encryptedData的方式，或者我将其转换为base64编码的字符串并将其写入文件的方式，或者我解密byte[] RawBytes的方式，或者我将解密的csD转换回字符串的方式。如果有人能指出我的错误，我会很感激的。

更新:在David的评论之后，我正在仔细研究IV.我现在正试图使用16个零。

在iOS上，我使用:

(const void *)[@"0000000000000000" dataUsingEncoding:NSUTF8StringEncoding].bytes

在。net上我使用:

new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }