Need help coverting char* to char

mmavipc · #1 20-Jul-2008, 18:22

Hello I am writing a plugin for AutoIt(autoitscript.com). The problem is that the function used in the AutoIt plugin sdk to get a parameter from the function call in AutoIt returns a char*, whats wrong with that is that the function I wish to use it in will not accept a char*, It will only accept a char. Here is my code.

CPP / C++ / C Code:

char encrypted_buffer[10000]; //big chunk of space :D some packets hit more than 9k you know.
char *IV[4];
AU3_PLUGIN_DEFINE(enc)
{
    AU3_PLUGIN_VAR	*s2au3;
    char *packet;
    int packetlen;
    IV[0] = AU3_GetString(&p_AU3_Params[0]);
    IV[1] = AU3_GetString(&p_AU3_Params[1]);
    IV[2] = AU3_GetString(&p_AU3_Params[2]);
    IV[3] = AU3_GetString(&p_AU3_Params[3]);
    packet = AU3_GetString(&p_AU3_Params[4]);
    packetlen = AU3_GetInt32(&p_AU3_Params[5]);
    InitEncryption(51);
    char buf2send[10240]; //10k ok buf space becuase packets can get bigger than 9k
    char result[10240]; //result of encryption
    char *au3ready;
    strcpy(buf2send,packet);
    mc_encrypt(IV, buf2send, result, packetlen);
    for (int i=0;i<packetlen;i++){
        au3ready[i] = result[i];
    }
    s2au3 = AU3_AllocVar ();
    AU3_SetString(s2au3,au3ready);
   	*p_AU3_Result		= s2au3;
	*n_AU3_ErrorCode	= 0;
	*n_AU3_ExtCode		= 0;   
}

The variable that is the problem is IV. mc_encrypt will only accept a char array and not a char* array. If you are wondering where mc_encrypt is defined, it's defined here:

CPP / C++ / C Code:

int InitEncryption(int value){
	HINSTANCE hGetProcIDDLL = LoadLibraryA("MapleCrypto");
	mc_initalize = pIC_InitDeInit(GetProcAddress(HMODULE (hGetProcIDDLL), "Initialize"));
	mc_finalize = pIC_InitDeInit(GetProcAddress(HMODULE (hGetProcIDDLL), "Finalize"));
	mc_encrypt = pIC_EncDecrypt(GetProcAddress(HMODULE (hGetProcIDDLL), "Encrypt"));
	mc_decrypt = pIC_EncDecrypt(GetProcAddress(HMODULE (hGetProcIDDLL), "Decrypt"));
	mc_encryptWithHeaderToClient = pIC_HeaderEncrypt(GetProcAddress(HMODULE (hGetProcIDDLL), "EncryptWithHeaderToClient"));
	mc_encryptWithHeaderToServer = pIC_HeaderEncrypt(GetProcAddress(HMODULE (hGetProcIDDLL), "EncryptWithHeaderToServer"));
	mc_generateIV = pIC_GenerateIV(GetProcAddress(HMODULE (hGetProcIDDLL), "GenerateIV"));
	return mc_initalize(value);
}

Thanks in advanced

transfrank · #2 21-Jul-2008, 14:11

Quote:

the function I wish to use it in will not accept a char*, It will only accept a char. Here is my code.

1:
That would tend to make more sense for the initial word of an encryption function to use chars.
You need each IV[] to contain a character and declare char IV[4]; You could then stuff it with whatever 8 bit values you want. I don't really see why you decide to stuff it with addresses, and the latter are not 8 bit long either.

2:
I see one problem with your code: Here, this pointer is uninitialized

CPP / C++ / C Code:

char *au3ready;

So over here, you are just writing to some arbitrary memory location:

CPP / C++ / C Code:

au3ready[i] = result[i];

You have a pointer to a single char. I think you really want a char auready3[10240].

3:
Over here at:

CPP / C++ / C Code:

strcpy(buf2send,packet);

The compiler is not forcing to copy all 10240 indices. You may want a strncpy and think about forcing the non used chars to zero.

4:Try to use malloc to allocate chunks of memory, with free to release the chuncks. You have a ton of space there and you could put a different size each time you run them.

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Need help coverting char* to char

Re: Need help coverting char* to char