如何将字节数组从C ++返回到C#

时间:2013-01-31 19:12:11

标签: c# c++ pointers marshalling

所以我一直在努力解决这个问题。我正在尝试将自己的AES 128库用于我的一个程序。该库测试并在C ++中工作(很好用于加密功能..我还没有实现其他功能)'加密'功能是这样的:

新代码

void Aes128Class::EncryptBlock(BYTE* outBlock, const BYTE* inBlock, const BYTE* cipherBlock)
{
    BYTE temp[16] = {0x00};
    Galois::XorBlock(temp, inBlock);
    Galois::XorBlock(temp, cipherBlock);

    BYTE expandedKey[176] = {0x00};
    memcpy(expandedKey, Key, 16);
    Galois::expand_key(expandedKey);

    Galois::XorBlock(temp, expandedKey);
    for(int i=16; i<160; i+=16)
    {
        Galois::DoRound(temp, &expandedKey[i]);
    }
    Galois::SubBytes(temp);
    Galois::ShiftRows(temp);
    Galois::XorBlock(temp, &expandedKey[160]);

    memcpy(outBlock, temp, 16);
}
void Aes128Class::EncryptData(BYTE* outBlock, size_t& outlen, const BYTE* inBlock, size_t length)
{
    float blockSize = (float)(length/16);
    blockSize = ceilf(blockSize);
    int newLength = (int)(blockSize*16);
    BYTE* temp = (BYTE*)malloc(newLength);
    BYTE* padd = (BYTE*)malloc(newLength);
    memset(temp, 0, newLength);
    memcpy(padd, inBlock, length);
    EncryptBlock(temp, padd, IV);
    for (int i=1; i<blockSize; i++)
    {
        EncryptBlock(&temp[i*16], &padd[i*16], &temp[(i-1)*16]);
    }
    outlen = newLength;
    memcpy(outBlock, temp, newLength);
}

这个想法是,如果plainText不是16字节的块增量,那么我强制它。所以这就产生了一个可变大小的字节数组。它适用于我的C++测试,但是当我在C#中调用它时,我会遇到一些不同的错误...这需要一分钟来描述。

    [DllImport("CppAes128.dll", CallingConvention = CallingConvention.ThisCall,
        EntryPoint = "?EncryptData@Aes128Class@@QAEXPAEAAIPBEI@Z")]
    static extern void EncryptData(IntPtr pClass, ref IntPtr outblock, [Out]int OutLength, byte[] inBlock, int length);

当我调用它时,我得到array和outlength的有效指针。它现在看起来的方式会导致访问冲突,但如果我将[Out]int OutLength更改为ref IntPtr,我可以使该结构生效。有趣的是,如果我ref intref uint它仍然“有效”。因此,如果我这样做,我会尝试阅读intptr,然后我会收到访问冲突。我在x86 project中将其编译为.NET 4.0(因为我在某处看到3.5有一些有访问权限的错误...)

以下是我在C#中尝试过的内容。这有点乱,因为我已经玩了几个小时(对不起):

    public byte[] EncryptData(byte[] plainText, int length)
    {
        byte[] enc = null;
        int len = 0;
        IntPtr pArray = IntPtr.Zero;
        EncryptData(theClass, ref pArray, len, plainText, length);

        Console.WriteLine(len);
        //enc = new byte[len];
        //Marshal.Copy(pArray, enc, 0, len);
        //Marshal.Release(pArray);
        //try
        //{
        //    int elementSize = Marshal.SizeOf(typeof(IntPtr));
        //    //IntPtr unmanagedArray = Marshal.AllocHGlobal(10 * elementSize);
        //    Console.WriteLine("Reading unmanaged memory:");
        //    // Print the 10 elements of the C-style unmanagedArray 
        //    for (int i = 0; i < 10; i++)
        //    {
        //        Console.WriteLine("{0:X2}:", Marshal.ReadByte(pArray, i));
        //    }

        //    Marshal.FreeHGlobal(pArray);

        //}
        //catch (Exception ex)
        //{
        //    Console.WriteLine("{0}\n{1}", ex.Source, ex.Message);
        //    Console.WriteLine("Win32({0})", Marshal.GetLastWin32Error());
        //}
        //Marshal.Release(pArray);
        return enc;
    }

唯一有效的时间是我刚制作一个静态大小的数组并且没有使用refmarshal副本或任何东西..我认为我的签名是这样的

static extern void EncryptData(IntPtr pClass, byte[] outBlock, byte[] inBlock, int length);

这几乎有效,但问题是,当我在foreach上进行array循环时,它总是我放的大小...至少可以说令人沮丧。

那么我做错了什么?我怎么能让这个工作?我很沮丧。谢谢

哦,仅供参考,我不能再依赖cryptlib了。我正在尝试重新编译一个使用cryptlib的不同项目作为静态库而不是共享,这会导致我的编译选项出现一些问题,而且回头的麻烦太大了。

已编辑以显示更多代码

这是我使用的测试。我找到了一个显示大量测试的网页,所以这就是我实现这个。

void VerifyEncrypt16(const BYTE* expected, const BYTE* key, const BYTE* iv, const BYTE* plainText)
{
    BYTE actual[16] = {0x00};
    Aes128Class aes;
    aes.SetKey(key, 16);
    aes.SetIV(iv, 16);
    size_t len = 0;
    aes.EncryptData(actual, len, plainText, 16);
    _ASSERT(CompareTwoArrays(expected, actual));
}
void VerifyEncrypt16String(const char* expected, const char* key, const char* iv, const char* plainText)
{
    BYTE e[16];
    BYTE k[16];
    BYTE i[16];
    BYTE p[16];

    ByteUtil::StringToHex(expected, e);
    ByteUtil::StringToHex(key, k);
    ByteUtil::StringToHex(iv, i);
    ByteUtil::StringToHex(plainText, p);

    VerifyEncrypt16(e, k, i, p);
}
void CheckEncrypt16(void)
{
    _RPT0(_CRT_WARN, "Checking Encryption of a 16 byte number IV set to 0\n");
    //AESVS GFSbox test data for CBC
    VerifyEncrypt16String("0336763e966d92595a567cc9ce537f5e","00000000000000000000000000000000","00000000000000000000000000000000","f34481ec3cc627bacd5dc3fb08f273e6");
    VerifyEncrypt16String("a9a1631bf4996954ebc093957b234589","00000000000000000000000000000000","00000000000000000000000000000000","9798c4640bad75c7c3227db910174e72");
    VerifyEncrypt16String("ff4f8391a6a40ca5b25d23bedd44a597","00000000000000000000000000000000","00000000000000000000000000000000","96ab5c2ff612d9dfaae8c31f30c42168");
    VerifyEncrypt16String("dc43be40be0e53712f7e2bf5ca707209","00000000000000000000000000000000","00000000000000000000000000000000","6a118a874519e64e9963798a503f1d35");
    VerifyEncrypt16String("92beedab1895a94faa69b632e5cc47ce","00000000000000000000000000000000","00000000000000000000000000000000","cb9fceec81286ca3e989bd979b0cb284");
    VerifyEncrypt16String("459264f4798f6a78bacb89c15ed3d601","00000000000000000000000000000000","00000000000000000000000000000000","b26aeb1874e47ca8358ff22378f09144");
    VerifyEncrypt16String("08a4e2efec8a8e3312ca7460b9040bbf","00000000000000000000000000000000","00000000000000000000000000000000","58c8e00b2631686d54eab84b91f0aca1");

    //AESVS KeySbox test data for CBC
    VerifyEncrypt16String("6d251e6944b051e04eaa6fb4dbf78465","10a58869d74be5a374cf867cfb473859","00000000000000000000000000000000","00000000000000000000000000000000");
    //A TON OF MORE TESTS! etc etc etc        VerifyEncrypt16String("5c005e72c1418c44f569f2ea33ba54f3","00000000000000000000000000000000","00000000000000000000000000000000","fffffffffffffffffffffffffffffffe");
    VerifyEncrypt16String("3f5b8cc9ea855a0afa7347d23e8d664e","00000000000000000000000000000000","00000000000000000000000000000000","ffffffffffffffffffffffffffffffff");
}

2 个答案:

答案 0 :(得分:1)

坦率地说,我发现最简单的方法是使用托管C ++调用包装非托管C ++调用。在托管C ++中,您可以以直接的C ++方式复制数据(通过固定数据结构)并将其传递回C#

答案 1 :(得分:1)

如果你仍在寻找答案,这个例子给出了一个起点。

基本上,从本机函数调用中分配内存块开始,而不是调用调用 - 返回到您传递(通过ref)数组的托管,并从原始输入参数列表中保存其大小。

这样,您可以为托管代码中的托管代码分配内存块,并使用本机内容进行编辑。

http://msdn.microsoft.com/en-us/library/ektebyzx.aspx

另一种方法很好找,性能比较会是一个奖励:)