/****************************************************************/
/* 802.16 dot16KDF CMAC Test Vector Generator                   */
/* Author: David Johnston                                       */
/* Email (home): dj@deadhat.com                                 */
/* Email (general): david.johnston@ieee.org                     */
/* Version 0.2                                                  */
/*                                                              */
/* v0.1     First version                                       */
/* v0.2     Fixes error in V0.1, switching truncate from        */
/*          leftmost n bytes to rightmost n bytes, thus         */
/*          making the vectors match Samsumg's                  */
/****************************************************************/
 
#include <stdlib.h>
#include <stdio.h>


#define NUM_TEST_CASES 5 

int test_case_astringlen[] =   {4, 4, 4, 4, 4};  /* astring length in bytes */

unsigned char test_case_astring[] =
{
	0x74, 0x65, 0x73, 0x74,
	0x74, 0x65, 0x73, 0x74,
	0x74, 0x65, 0x73, 0x74,
	0x74, 0x65, 0x73, 0x74,
	0x74, 0x65, 0x73, 0x74

};

unsigned char keys[] =
{
    0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
    0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
    0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
    0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
    0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f
};

unsigned int test_case_keylength[] = {8, 16, 20, 40, 48};

/*****************************/
/******** SBOX Table *********/
/*****************************/

    unsigned char sbox_table[256] =
    {
        0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5,
        0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
        0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0,
        0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
        0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc,
        0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
        0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a,
        0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
        0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0,
        0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
        0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b,
        0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
        0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85,
        0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
        0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5,
        0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
        0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17,
        0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
        0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88,
        0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
        0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c,
        0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
        0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9,
        0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
        0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6,
        0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
        0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e,
        0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
        0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94,
        0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
        0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68,
        0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16
    };

/*****************************/
/**** Function Prototypes ****/
/*****************************/

void get_testcase(      int test_case,
                        unsigned char *astring,
                        unsigned int *astringlength,
                        unsigned char *key,
                        unsigned int *keylength);

int cmac(   unsigned char *key,
		unsigned char *k1,
		unsigned char *k2,
		unsigned char *plaintext,
                unsigned int length,
                unsigned char *t);

void xor_128(unsigned char *a, unsigned char *b, unsigned char *out); void leftshift128(unsigned char *a, unsigned char *out); void xor_32(unsigned char *a, unsigned char *b, unsigned char *out); unsigned char sbox(unsigned char a); void next_key(unsigned char *key, int round); void byte_sub(unsigned char *in, unsigned char *out); void shift_row(unsigned char *in, unsigned char *out); void mix_column(unsigned char *in, unsigned char *out); void add_round_key( unsigned char *shiftrow_in,
                    unsigned char *mcol_in,
                    unsigned char *block_in,
                    int round,
                    unsigned char *out); void aes128k128d(unsigned char *key, unsigned char *data, unsigned char *ciphertext);

void testvector_print(char *str, unsigned char* block) {
	printf("%s%02x%02x%02x%02x %02x%02x%02x%02x %02x%02x%02x%02x %02x%02x%02x%02x\n", str,
		block[0], block[1], block[2], block[3],
		block[4], block[5], block[6], block[7],
		block[8], block[9], block[10], block[11],
		block[12], block[13], block[14], block[15]); }

void testvector_print_be(char *str, unsigned char* block) {
	printf("%s%02x%02x%02x%02x %02x%02x%02x%02x %02x%02x%02x%02x %02x%02x%02x%02x\n", str,
		block[15], block[14], block[13], block[12],
		block[11], block[10], block[9], block[8],
		block[7], block[6], block[5], block[4],
		block[3], block[2], block[1], block[0]); }

/****************************************/
/* aes128k128d()                        */
/* Performs a 128 bit AES encrypt with  */
/* 128 bit data.                        */
/****************************************/
void xor_128(unsigned char *a, unsigned char *b, unsigned char *out) {
    int i;
    for (i=0;i<16; i++)
    {
        out[i] = a[i] ^ b[i];
    }
}

void xor_32(unsigned char *a, unsigned char *b, unsigned char *out) {
    int i;
    for (i=0;i<4; i++)
    {
        out[i] = a[i] ^ b[i];
    }
}
unsigned char sbox(unsigned char a)
{
    return sbox_table[(int)a];
}

void next_key(unsigned char *key, int round) {
    unsigned char rcon;
    unsigned char sbox_key[4];
    unsigned char rcon_table[12] =
    {
        0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
        0x1b, 0x36, 0x36, 0x36
    };

    sbox_key[0] = sbox(key[13]);
    sbox_key[1] = sbox(key[14]);
    sbox_key[2] = sbox(key[15]);
    sbox_key[3] = sbox(key[12]);

    rcon = rcon_table[round];

    xor_32(&key[0], sbox_key, &key[0]);
    key[0] = key[0] ^ rcon;

    xor_32(&key[4], &key[0], &key[4]);
    xor_32(&key[8], &key[4], &key[8]);
    xor_32(&key[12], &key[8], &key[12]); }

void byte_sub(unsigned char *in, unsigned char *out) {
    int i;
    for (i=0; i< 16; i++)
    {
        out[i] = sbox(in[i]);
    }
}

void shift_row(unsigned char *in, unsigned char *out) {
    out[0] =  in[0];
    out[1] =  in[5];
    out[2] =  in[10];
    out[3] =  in[15];
    out[4] =  in[4];
    out[5] =  in[9];
    out[6] =  in[14];
    out[7] =  in[3];
    out[8] =  in[8];
    out[9] =  in[13];
    out[10] = in[2];
    out[11] = in[7];
    out[12] = in[12];
    out[13] = in[1];
    out[14] = in[6];
    out[15] = in[11];
}

void mix_column(unsigned char *in, unsigned char *out) {
    int i;
    unsigned char add1b[4];
    unsigned char add1bf7[4];
    unsigned char rotl[4];
    unsigned char swap_halfs[4];
    unsigned char andf7[4];
    unsigned char rotr[4];
    unsigned char temp[4];
    unsigned char tempb[4];

    for (i=0 ; i<4; i++)
    {
        if ((in[i] & 0x80)== 0x80)
            add1b[i] = 0x1b;
        else
            add1b[i] = 0x00;
    }

    swap_halfs[0] = in[2];    /* Swap halfs */
    swap_halfs[1] = in[3];
    swap_halfs[2] = in[0];
    swap_halfs[3] = in[1];

    rotl[0] = in[3];        /* Rotate left 8 bits */
    rotl[1] = in[0];
    rotl[2] = in[1];
    rotl[3] = in[2];

    andf7[0] = in[0] & 0x7f;
    andf7[1] = in[1] & 0x7f;
    andf7[2] = in[2] & 0x7f;
    andf7[3] = in[3] & 0x7f;

    for (i = 3; i>0; i--)    /* logical shift left 1 bit */
    {
        andf7[i] = andf7[i] << 1;
        if ((andf7[i-1] & 0x80) == 0x80)
        {
            andf7[i] = (andf7[i] | 0x01);
        }
    }
    andf7[0] = andf7[0] << 1;
    andf7[0] = andf7[0] & 0xfe;

    xor_32(add1b, andf7, add1bf7);

    xor_32(in, add1bf7, rotr);

    temp[0] = rotr[0];         /* Rotate right 8 bits */
    rotr[0] = rotr[1];
    rotr[1] = rotr[2];
    rotr[2] = rotr[3];
    rotr[3] = temp[0];

    xor_32(add1bf7, rotr, temp);
    xor_32(swap_halfs, rotl,tempb);
    xor_32(temp, tempb, out);
}

void aes128k128d(unsigned char *key, unsigned char *data, unsigned char *ciphertext) {
    int round;
    int i;
    unsigned char intermediatea[16];
    unsigned char intermediateb[16];
    unsigned char round_key[16];

    for(i=0; i<16; i++) round_key[i] = key[i];

    for (round = 0; round < 11; round++)
    {
        if (round == 0)
        {
            xor_128(round_key, data, ciphertext);
            next_key(round_key, round);         
        }
        else if (round == 10)
        {
            byte_sub(ciphertext, intermediatea);
            shift_row(intermediatea, intermediateb);
            xor_128(intermediateb, round_key, ciphertext);          
        }
        else    /* 1 - 9 */
        {
            byte_sub(ciphertext, intermediatea);
            shift_row(intermediatea, intermediateb);
            mix_column(&intermediateb[0], &intermediatea[0]);
            mix_column(&intermediateb[4], &intermediatea[4]);
            mix_column(&intermediateb[8], &intermediatea[8]);
            mix_column(&intermediateb[12], &intermediatea[12]);
            xor_128(intermediatea, round_key, ciphertext);
            next_key(round_key, round);
        }
    }

}


/****************************************/
/* leftshifts by 1 bit a 128 bit vector */
/****************************************/

/* Take note that in the NIST CMAC specification
   the MSB is byte index 0, so the carries go the
   other way to the way you might expect */

void leftshift128(unsigned char *a, unsigned char *out) {
	unsigned char x;
	int carry;
	int i;
	carry=0;

	for (i=15; i >= 0 ; i--)
	{	
		x = a[i] << 1;
		if (carry == 1)
		{
			x = x | 0x01;
		}
		else
		{
			x = x & 0xfe;
		}

		out[i] = x;

		carry = 0;
		if ((a[i] & 0x80)==0x80) carry = 1;
	}

}

/********************************************************/
/* int cmac()                                           */
/* Computes the 128 bit CMAC of the plaintext           */
/********************************************************/

int cmac(   unsigned char *key,
		unsigned char *k1,
		unsigned char *k2,
		unsigned char *plaintext,
                unsigned int length,
                unsigned char *t)
{

	unsigned char l[16];
	unsigned char lshl[16];

	unsigned char r[16] = {0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x87 };
	unsigned char zeroes[16] = {0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00 };

	unsigned char c[16] = {0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00 };
	unsigned char temp[16] = {0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00 };
	unsigned char mn[16] = {0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00 };
	unsigned char *m;

	unsigned int n;
	unsigned int i;
	unsigned int remainder;

	/* Compute subkeys K1 and K2 */

	aes128k128d(key, zeroes, l);
	if ((l[0] & 0x80) == 0x80)  /* if MSB of L is set */
	{
		leftshift128(l,lshl);
		xor_128(lshl,r,k1);
	}
	else
	{
		leftshift128(l,k1);
	};

	
	if ((k1[0] & 0x80) == 0x80)  /* if MSB of K1 is set */
	{
		leftshift128(k1,lshl);
		xor_128(lshl,r,k2);
	}
	else
	{
		leftshift128(k1,k2);
	};

	/* Compute the MAC */

	n = length/16;
	remainder = length % 16;

	if (remainder != 0) { n++; };

	for (i=0; i<16; i++) {c[i] = 0x00;};	/* Set c0 to all zeroes */

	for (i = 0; i< n-1; i++)
	{
		m = (unsigned char *)(plaintext+(16*i));
		xor_128(c,m,temp);
		aes128k128d(key, temp, c);
	};

					/* Final block */
	if (remainder == 0)
	{
		m = plaintext+(16*(n-1));
		xor_128(m, k1, mn);
		xor_128(c, mn, temp);
		aes128k128d(key,temp, t);
	}
	else
	{
		for (i=0; i<16; i++) temp[i]=0x00; /* clear temp */

						/* copy last fragment into temp */
		m = plaintext+(16*(n-1));
		for (i=0; i<remainder; i++)
		{
			temp[i] = m[i];	
		}

						/* set the leftmost bit of the padding */
		temp[remainder] = 0x80;

		xor_128(temp, k2, mn);
		xor_128(mn, c, temp);

		aes128k128d(key, temp, t);

	}

	

};

/************************************************/
/* get_testcase(testcase number)                */
/* Copies a testcase from the test case data    */
/************************************************/
void get_testcase(      int test_case,
                    	unsigned char *astring,
			unsigned int *astringlength,
			unsigned char *key,
			unsigned int *keylength)
{
    int i;
    unsigned char *ptr;

    unsigned int length;
    
    ptr = test_case_astring;
    for (i=0; i< (test_case-1); i++)    /* Iterate through test cases */
    {
	length = test_case_astringlen[i];
        ptr = ptr + length;
    }

	length = test_case_astringlen[test_case-1];
	*astringlength = length;
	
    for (i=0; i< length; i++)
    {
        astring[i] = *ptr++;
    }

    for (i=0; i < 16; i++)
    {
        key[i] = keys[(16 * (test_case-1))+i];
    }

    *keylength = test_case_keylength[test_case-1];
}

/**************************************************/
/* dot16KDF                                       */
/* Implements the dot16KDF in the 802.16e spec    */
/* Except keylength and result are limited to     */
/* byte boundaries and the input key must be      */
/* 16 bytes                                       */
/**************************************************/

dot16KDF(
		unsigned char *astring,
		unsigned int astringlength,
		unsigned char *key,
		unsigned int keylength,
		unsigned char *result
		)
{
	unsigned int ptr;
	unsigned char plaintext[200];
	unsigned int length;
	unsigned char k1[16];
	unsigned char k2[16];
	unsigned char t[16];

	unsigned int i;
	unsigned int j;
	int resultlength;

	unsigned int keylength_bits;
	unsigned int pre_truncated_keylength;
	unsigned int truncate_amount;

	keylength_bits = keylength * 8;

	resultlength=0;

	pre_truncated_keylength = (((keylength_bits-1)/128)+1)*16;
	truncate_amount = pre_truncated_keylength - keylength;

	for (i=0; i <= ((keylength_bits-1)/128); i++)
	{
		plaintext[0] = (unsigned char) ((i >> 24) & 0xff);  /* Put MSB of i first */
		plaintext[1] = (unsigned char) ((i >> 16) & 0xff);
		plaintext[2] = (unsigned char) ((i >> 8) & 0xff);
		plaintext[3] = (unsigned char) ( i  & 0xff);        /* Put LSB of i last */

		ptr=4;

		for (j=0; j<astringlength; j++)
		{
			plaintext[ptr++] = astring[j];
		}

		plaintext[ptr++] = ((keylength_bits >> 24) & 0xff);
		plaintext[ptr++] = ((keylength_bits >> 16) & 0xff);
		plaintext[ptr++] = ((keylength_bits >> 8) & 0xff);
		plaintext[ptr++] = (keylength_bits  & 0xff);
		
		length = astringlength + 8; /* length of string + 4 bytes for i and 4 bytes for keylength */
		
        	cmac(
			key,
			k1,
			k2,
			plaintext,
			length,
			t);

		for (j=truncate_amount;j<16;j++) /* Skip the first truncate_amount bytes */
		{
			result[resultlength++] = t[j];  /* copy the cmac to the result */
		}
		truncate_amount = 0;
	}

	

}

/****************************************************/
/* main()                                           */
/* Iterate through the test cases, passing them     */
/* through the KDF algorithm to produce test        */
/* vectors                                          */
/****************************************************/

int main()
{
	int test_case;
	int i;
	int j;
	int num_blocks;
	int block_remainder;

	unsigned char astring[200]; /* The constant string argument to dot16KDF */
	unsigned int astringlength;
	
	unsigned int keylength; /* the keylength being requested from dot16KDF in bytes, not the length of the key input */
	
	unsigned char key[16]; /* the input key, 128 bits */

	unsigned char result[200];

	for (i=0; i<200; i++) result[i]= 0x25; 
	
    for (test_case = 1; test_case < (NUM_TEST_CASES+1); test_case++)
    {
        printf ("\nTEST CASE %02X\n",test_case);

        get_testcase(test_case, astring, &astringlength, key, &keylength);

	dot16KDF(astring, astringlength, key, keylength, result);

	astring[astringlength]= 0x00;
	
        testvector_print("\tKEY (msb-lsb)     = ", key);
	printf          ("\tastring           = %s\n", astring);
      	printf          ("\tastring length    = %d\n", astringlength);
	printf		("\tKeylength         = %d bits\n", keylength*8);
	
        num_blocks = (keylength) / 16;              /* Calculate number of 16 byte blocks */
        block_remainder = (keylength) % 16;

	printf("\tDot16KDF returns  = ");

        for (i=0;i<num_blocks; i++)                /* Print the message as lines of 16 bytes */
        {
            if (i != 0) printf("\t\t\t    "); 
            for (j=0; j<16;j++)
            {
                printf("%02x",result[j + (i*16)]);
		if ((j==3) | (j==7) | (j==11)) { printf(" "); };
            }
            printf("\n");
        }

        if (block_remainder > 0)                   /* Print the final line */
        {
            if (num_blocks != 0) printf("\t\t\t    ");
            for (j=0; j<block_remainder;j++)
            {
                printf("%02x",result[j + (num_blocks*16)]);
		if ((j==3) | (j==7) | (j==11)) { printf(" "); };
            }
            printf("\n");
        }
    }

    return 0;
}