//Thanks for reading DISCLAIMER.txt

/*
	This samples shows how to seed the PRNG using C_SeedRandom.
*/


#include <iostream>
#include <cryptoki.h>
#include <stdlib.h>
#include <string.h>

using namespace std;


#ifdef NIX
	#include 
#else
	#include 
#endif


#ifdef NIX
	void *libHandle = 0;
#else
	HINSTANCE libHandle = 0; 
#endif


CK_FUNCTION_LIST *p11Func = NULL;
CK_SLOT_ID slotId = 0;
CK_SESSION_HANDLE hSession = 0;
CK_BYTE *slotPin = NULL;
const char *libPath = NULL;
CK_BYTE *randomData = NULL;
CK_ULONG dataLen = 16;


// This function loads a pkcs11 library. Path of the pkcs11 library is read using P11_LIB environment variable.
void loadHSMLibrary()
{
	libPath = getenv("P11_LIB");
	if(libPath==NULL)
	{
		cout << "P11_LIB environment variable not set." << endl;
		exit(1);
	}


	#ifdef NIX
		libHandle = dlopen(libPath, RTLD_NOW);
	#else
		libHandle = LoadLibrary(libPath);
	#endif


	if(!libHandle)
	{
		cout << "Failed to load P11 library. " << libPath << endl;
		exit(1);
	}


	#ifdef NIX
		CK_C_GetFunctionList C_GetFunctionList = (CK_C_GetFunctionList)dlsym(libHandle,"C_GetFunctionList");
	#else
		CK_C_GetFunctionList C_GetFunctionList = (CK_C_GetFunctionList)GetProcAddress(libHandle,"C_GetFunctionList");
	#endif


	C_GetFunctionList(&p11Func);
	if(!p11Func)
	{
		cout << "Failed to load P11 Functions." << endl;
		exit(1);
	}
}



// Before exiting, this functions performs some memory cleanup.
void freeResource()
{
	#ifdef NIX
		dlclose(libHandle);
	#else
		FreeLibrary(libHandle);
	#endif
        p11Func = NULL;
        slotPin = NULL;
}


// Converts byte array to Hex String.
void printHex(CK_BYTE *bytes, int len)
{
	for(int ctr = 0; ctr < len; ctr++)
	{
		printf("%02x", bytes[ctr]);
	}
	cout << endl;
}


// This function checks if a requested PKCS #11 operation was a success or a failure.
void checkOperation(CK_RV rv, const char *message)
{
	if(rv!=CKR_OK)
	{
		cout << message << " failed with : " << rv << endl;
		printf("RV : %#08lx", rv);
		freeResource();
		exit(1);
	}
}


// This function connects this sample to a slot. It initializes the library, opens a new session and performs login.
void connectToSlot()
{
	checkOperation(p11Func->C_Initialize(NULL_PTR),"C_Initialize");
	checkOperation(p11Func->C_OpenSession(slotId, CKF_SERIAL_SESSION | CKF_RW_SESSION, NULL_PTR, NULL_PTR, &hSession),"C_OpenSession");
	checkOperation(p11Func->C_Login(hSession, CKU_USER, slotPin, strlen((const char*)slotPin)),"C_Login");
}


// This function disconnects this sample from a slot. It first logs out of the slot, closes the session and then finalizes the library.
void disconnectFromSlot()
{
	checkOperation(p11Func->C_Logout(hSession),"C_Logout");
	checkOperation(p11Func->C_CloseSession(hSession),"C_CloseSesion");
	checkOperation(p11Func->C_Finalize(NULL_PTR),"C_Finalize");
}


// This function generates random data
void generateRandomData()
{
	CK_BYTE seedValue[] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07};
	checkOperation(p11Func->C_SeedRandom(hSession, seedValue, sizeof(seedValue)), "C_SeedRandom()");
	randomData = new CK_BYTE[dataLen];
    checkOperation(p11Func->C_GenerateRandom(hSession, randomData, dataLen), "C_GenerateRandom");
}


// This function shows the usage of the executable.
void usage(char exeName[30])
{
	cout << "Command usage is :-" << endl;
	cout << exeName << "  " << "" << endl;
	exit(0);
}


int main(int argc, char **argv)
{
	if(argc!=3) 
		usage(argv[0]); 
	else 
	{
		slotId = atoi(argv[1]);
		slotPin = new CK_BYTE[strlen(argv[2])];
		slotPin = (CK_BYTE_PTR)argv[2];
	}

	loadHSMLibrary();
	cout << "P11 library loaded." << endl;
	connectToSlot();
	cout << "Connected via session : " << hSession << endl;
    generateRandomData();

	cout << endl << "Random Data : ";
	printHex(randomData, dataLen);
		
	disconnectFromSlot();
	cout << "Disconnected from slot." << endl;
	freeResource();
	return 0;
}