LPSTR and LPBYTE passing to a dll

[Paul_591]

Guys, I am an accomplished embedded coder, but not very adept with windows programming or COM. However, I have a quick command line program to write to make use of a seed2key dll. The dlls prototype is.. API seed2key(char *seed, BYTE *key). I know this because I have the source code for it. However, when trying to use the seed2key function in a C++ console app, the compiler thinks that the parameters should be of type LPSTR and LPBYTE respectively. Unfortunately I have no idea what these are. I have a 16 byte array carrying the seed, that i need to pass to this function. How do i create an LPSTR from that? Does anyone have any idea what parameters it is actually after, and can provide me with a way to do so? Many Thanks to anyone who can help. Paul.

[JonEngle]

LPSTR = long pointer to string, ie char * LPBYTE = long pointer to byte, ie BYTE * -> ie unsigned char * Do you have the code snippet that's failing to build?

[Paul_591]

Thanks for that! I couldnt find that information anywhere on the web! The code snippet is below. It is VERY rough as I am hacking around to get a solution. :-) int main() { BOOL procReturn = 0; HINSTANCE dllHandle = NULL; KWP_COMPUTEKEYFROMSEED pSeedAndKeyFunc = NULL; dllHandle = LoadLibrary("seed_inv.dll"); if (!dllHandle) { cout<< "Failed to Load dll" << endl; } else { cout<< "DLL loaded OK" << endl; } if (dllHandle) pSeedAndKeyFunc = (KWP_COMPUTEKEYFROMSEED) GetProcAddress(dllHandle, "seed2key"); if (!pSeedAndKeyFunc) { cout<< "ProcAddress Failed"<

[JonEngle]

This should work: BYTE seed[16] = {0x1,0x2,0x3,0x4,0x5,0x6,0x7,0x8,0x9,0xa,0xb,0xc,0xd,0xe,0xf,0x00}; status = (*pSeedAndKeyFunc)((LPSTR)seed,key); it's probably looking for the null terminator on the string.

[Paul_591]

Fantastic. That seems to work a treat. However, on the inside of the dll, the first function is this.. API seed2key (char *param, BYTE *key) { BYTE seed[16]; DWORD i, retLen, seedLen; BYTE *scanPtr; i = 0; scanPtr = strtok(param, " \t\n"); while (scanPtr && i < 16) { seed[i] = atoi(scanPtr); scanPtr = strtok(NULL, " \t\n"); i++; } seedLen = i; seedToKey (seed, seedLen, key, &retLen); return (retLen); } the while loop iterates once through correctly, but on the second time the string tokenizer returns 0x0000000 into scanPtr. When you hover over it in VS, the tooltip says. [scanPtr = 0x00000000 ]. The above section of code seems to suggest that it is actually requiring a string with the delimeters " ", tab and newline. Rather confusing - although seemingly a different issue, any ideas? Thanks for the previous posts! Paul.

[JonEngle]

I'd see if the seedToKey function their calling is exported, it seems like a safer function to use. Otherwise, I'd probably change this: BYTE seed[16] = {0x1,0x2,0x3,0x4,0x5,0x6,0x7,0x8,0x9,0xa,0xb,0xc,0xd,0xe,0xf,0x00}; to char seed[] = {0x1,'\n'...,'\n',0xf,0x00}; You can also eliminate the cast that way.