Thread: I am gonna kill myself...linker error !!!

Hey guys...i am so frigging frustrated right now its not even funny
I get the following linker error

Code:

MSVCRTD.lib(crtexe.obj) : error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup

The code compiles successfully only to leave me to die with the linker error
I am using Micorsoft Visual Studio 2005.I tried changing the subsystem in linker configuration to Windows,Not set etc etc.Just nothing has worked out till now.Also changed the entry point to my main fucntion.Heres the code if it helps.

Disclaimer: the code is not entirely mine...dont worry its no College assignment..i am having my vacations...just trying to do this out of hobby

Code:

typedef unsigned char Byte;

#include <stdio.h>
#include <stdlib.h>
/* #define TEST */
 
/*
 * rand[0..15]: the challenge from the base station
 * key[0..15]: the SIM's A3/A8 long-term key Ki
 * simoutput[0..11]: what you'd get back if you fed rand and key to a real
 * SIM.
 *
 *   The GSM spec states that simoutput[0..3] is SRES,
 *   and simoutput[4..11] is Kc (the A5 session key).
 *   (See GSM 11.11, Section 8.16.  See also the leaked document
 *   referenced below.)
 *   Note that Kc is bits 74..127 of the COMP128 output, followed by 10
 *   zeros.
 *   In other words, A5 is keyed with only 54 bits of entropy. This
 *   represents a deliberate weakening of the key used for voice privacy
 *   by a factor of over 1000.
 * 
 * Verified with a Pacific Bell Schlumberger SIM.  Your mileage may vary.
 *
 * Marc Briceno <[email protected]>, Ian Goldberg <[email protected]>,
 * and David Wagner <[email protected]>
 */
void A3A8(/* in */ Byte rand[16], /* in */ Byte key[16],
	/* out */ Byte simoutput[12]);

/* The compression tables. */
static const Byte table_0[512] = {
        102,177,186,162,  2,156,112, 75, 55, 25,  8, 12,251,193,246,188,
        109,213,151, 53, 42, 79,191,115,233,242,164,223,209,148,108,161,
        252, 37,244, 47, 64,211,  6,237,185,160,139,113, 76,138, 59, 70,
         67, 26, 13,157, 63,179,221, 30,214, 36,166, 69,152,124,207,116,
        247,194, 41, 84, 71,  1, 49, 14, 95, 35,169, 21, 96, 78,215,225,
        182,243, 28, 92,201,118,  4, 74,248,128, 17, 11,146,132,245, 48,
        149, 90,120, 39, 87,230,106,232,175, 19,126,190,202,141,137,176,
        250, 27,101, 40,219,227, 58, 20, 51,178, 98,216,140, 22, 32,121,
         61,103,203, 72, 29,110, 85,212,180,204,150,183, 15, 66,172,196,
         56,197,158,  0,100, 45,153,  7,144,222,163,167, 60,135,210,231,
        174,165, 38,249,224, 34,220,229,217,208,241, 68,206,189,125,255,
        239, 54,168, 89,123,122, 73,145,117,234,143, 99,129,200,192, 82,
        104,170,136,235, 93, 81,205,173,236, 94,105, 52, 46,228,198,  5,
         57,254, 97,155,142,133,199,171,187, 50, 65,181,127,107,147,226,
        184,218,131, 33, 77, 86, 31, 44, 88, 62,238, 18, 24, 43,154, 23,
         80,159,134,111,  9,114,  3, 91, 16,130, 83, 10,195,240,253,119,
        177,102,162,186,156,  2, 75,112, 25, 55, 12,  8,193,251,188,246,
        213,109, 53,151, 79, 42,115,191,242,233,223,164,148,209,161,108,
         37,252, 47,244,211, 64,237,  6,160,185,113,139,138, 76, 70, 59,
         26, 67,157, 13,179, 63, 30,221, 36,214, 69,166,124,152,116,207,
        194,247, 84, 41,  1, 71, 14, 49, 35, 95, 21,169, 78, 96,225,215,
        243,182, 92, 28,118,201, 74,  4,128,248, 11, 17,132,146, 48,245,
         90,149, 39,120,230, 87,232,106, 19,175,190,126,141,202,176,137,
         27,250, 40,101,227,219, 20, 58,178, 51,216, 98, 22,140,121, 32,
        103, 61, 72,203,110, 29,212, 85,204,180,183,150, 66, 15,196,172,
        197, 56,  0,158, 45,100,  7,153,222,144,167,163,135, 60,231,210,
        165,174,249, 38, 34,224,229,220,208,217, 68,241,189,206,255,125,
         54,239, 89,168,122,123,145, 73,234,117, 99,143,200,129, 82,192,
        170,104,235,136, 81, 93,173,205, 94,236, 52,105,228, 46,  5,198,
        254, 57,155, 97,133,142,171,199, 50,187,181, 65,107,127,226,147,
        218,184, 33,131, 86, 77, 44, 31, 62, 88, 18,238, 43, 24, 23,154,
        159, 80,111,134,114,  9, 91,  3,130, 16, 10, 83,240,195,119,253
    }, table_1[256] = {
         19, 11, 80,114, 43,  1, 69, 94, 39, 18,127,117, 97,  3, 85, 43,
         27,124, 70, 83, 47, 71, 63, 10, 47, 89, 79,  4, 14, 59, 11,  5,
         35,107,103, 68, 21, 86, 36, 91, 85,126, 32, 50,109, 94,120,  6,
         53, 79, 28, 45, 99, 95, 41, 34, 88, 68, 93, 55,110,125,105, 20,
         90, 80, 76, 96, 23, 60, 89, 64,121, 56, 14, 74,101,  8, 19, 78,
         76, 66,104, 46,111, 50, 32,  3, 39,  0, 58, 25, 92, 22, 18, 51,
         57, 65,119,116, 22,109,  7, 86, 59, 93, 62,110, 78, 99, 77, 67,
         12,113, 87, 98,102,  5, 88, 33, 38, 56, 23,  8, 75, 45, 13, 75,
         95, 63, 28, 49,123,120, 20,112, 44, 30, 15, 98,106,  2,103, 29,
         82,107, 42,124, 24, 30, 41, 16,108,100,117, 40, 73, 40,  7,114,
         82,115, 36,112, 12,102,100, 84, 92, 48, 72, 97,  9, 54, 55, 74,
        113,123, 17, 26, 53, 58,  4,  9, 69,122, 21,118, 42, 60, 27, 73,
        118,125, 34, 15, 65,115, 84, 64, 62, 81, 70,  1, 24,111,121, 83,
        104, 81, 49,127, 48,105, 31, 10,  6, 91, 87, 37, 16, 54,116,126,
         31, 38, 13,  0, 72,106, 77, 61, 26, 67, 46, 29, 96, 37, 61, 52,
        101, 17, 44,108, 71, 52, 66, 57, 33, 51, 25, 90,  2,119,122, 35
    }, table_2[128] = {
         52, 50, 44,  6, 21, 49, 41, 59, 39, 51, 25, 32, 51, 47, 52, 43,
         37,  4, 40, 34, 61, 12, 28,  4, 58, 23,  8, 15, 12, 22,  9, 18,
         55, 10, 33, 35, 50,  1, 43,  3, 57, 13, 62, 14,  7, 42, 44, 59,
         62, 57, 27,  6,  8, 31, 26, 54, 41, 22, 45, 20, 39,  3, 16, 56,
         48,  2, 21, 28, 36, 42, 60, 33, 34, 18,  0, 11, 24, 10, 17, 61,
         29, 14, 45, 26, 55, 46, 11, 17, 54, 46,  9, 24, 30, 60, 32,  0,
         20, 38,  2, 30, 58, 35,  1, 16, 56, 40, 23, 48, 13, 19, 19, 27,
         31, 53, 47, 38, 63, 15, 49,  5, 37, 53, 25, 36, 63, 29,  5,  7
    }, table_3[64] = {
          1,  5, 29,  6, 25,  1, 18, 23, 17, 19,  0,  9, 24, 25,  6, 31,
         28, 20, 24, 30,  4, 27,  3, 13, 15, 16, 14, 18,  4,  3,  8,  9,
         20,  0, 12, 26, 21,  8, 28,  2, 29,  2, 15,  7, 11, 22, 14, 10,
         17, 21, 12, 30, 26, 27, 16, 31, 11,  7, 13, 23, 10,  5, 22, 19
    }, table_4[32] = {
         15, 12, 10,  4,  1, 14, 11,  7,  5,  0, 14,  7,  1,  2, 13,  8,
         10,  3,  4,  9,  6,  0,  3,  2,  5,  6,  8,  9, 11, 13, 15, 12
    }, *table[5] = { table_0, table_1, table_2, table_3, table_4 };

void A3A8(/* in */ Byte rand[16], /* in */ Byte key[16],
	/* out */ Byte simoutput[12])
{
	Byte x[32], bit[128];
	int i, j, k, l, m, n, y, z, next_bit;

	/* ( Load RAND into last 16 bytes of input ) */
	for (i=16; i<32; i++)
		x[i] = rand[i-16];

	/* ( Loop eight times ) */
	for (i=1; i<9; i++) {
		/* ( Load key into first 16 bytes of input ) */
		for (j=0; j<16; j++)
			x[j] = key[j];
		/* ( Perform substitutions ) */
		for (j=0; j<5; j++)
			for (k=0; k<(1<<j); k++)
				for (l=0; l<(1<<(4-j)); l++) {
					m = l + k*(1<<(5-j));
					n = m + (1<<(4-j));
					y = (x[m]+2*x[n]) % (1<<(9-j));
					z = (2*x[m]+x[n]) % (1<<(9-j));
					x[m] = table[j][y];
					x[n] = table[j][z];
				}
		/* ( Form bits from bytes ) */
		for (j=0; j<32; j++)
			for (k=0; k<4; k++)
				bit[4*j+k] = (x[j]>>(3-k)) & 1;
		/* ( Permutation but not on the last loop ) */
		if (i < 8)
			for (j=0; j<16; j++) {
				x[j+16] = 0;
				for (k=0; k<8; k++) {
					next_bit = ((8*j + k)*17) % 128;
					x[j+16] |= bit[next_bit] << (7-k);
				}
			}
	}

	/*
	 * ( At this stage the vector x[] consists of 32 nibbles.
	 *   The first 8 of these are taken as the output SRES. )
	 */

	/* The remainder of the code is not given explicitly in the
	 * standard, but was derived by reverse-engineering.
	 */

	for (i=0; i<4; i++)
		simoutput[i] = (x[2*i]<<4) | x[2*i+1];
	for (i=0; i<6; i++)
		simoutput[4+i] = (x[2*i+18]<<6) | (x[2*i+18+1]<<2)
				| (x[2*i+18+2]>>2);
	simoutput[4+6] = (x[2*6+18]<<6) | (x[2*6+18+1]<<2);
	simoutput[4+7] = 0;
}

#ifdef TEST
int hextoint(char x)
{
	x = toupper(x);
	if (x >= 'A' && x <= 'F')
		return x-'A'+10;
	else if (x >= '0' && x <= '9')
		return x-'0';
	fprintf(stderr, "bad input.\n");
	exit(1);
}

int main(int argc, char **argv)
{
	Byte rand[16], key [16], simoutput[12];
	int i;

	if (argc != 3 || strlen(argv[1]) != 34 || strlen(argv[2]) != 34
			|| strncmp(argv[1], "0x", 2) != 0
			|| strncmp(argv[2], "0x", 2) != 0) {
		fprintf(stderr, "Usage: %s 0x<key> 0x<rand>\n", argv[0]);
		exit(1);
	}

	for (i=0; i<16; i++)
		key[i] = (hextoint(argv[1][2*i+2])<<4)
			| hextoint(argv[1][2*i+3]);
	for (i=0; i<16; i++)
		rand[i] = (hextoint(argv[2][2*i+2])<<4)
			 | hextoint(argv[2][2*i+3]);
	A3A8(key, rand, simoutput);
	printf("simoutput: ");
	for (i=0; i<12; i++)
		printf("%02X", simoutput[i]);
	printf("\n");
	return 0;
}
#endif