/* This is an independent implementation of the MARS encryption     */
/* algorithm  designed by a team at IBM as a candidate for the US   */
/* NIST Advanced Encryption Standard (AES) effort.  The algorithm   */
/* is covered by a pending patent application owned by IBM, who     */
/* intend to offer a royalty free license under any issued patent   */
/* that results from such application if MARS is selected as the    */
/* AES algorithm.  In the interim, you may evaluate the MARS        */
/* algorithm for your personal, lawful, non-profit purposes as an   */
/* end user.                                                        */
/*                                                                  */
/* Copyright in this implementation is held by Dr B R Gladman but   */
/* I hereby give permission for its free direct or derivative use   */
/* subject to acknowledgment of its origin and compliance with the  */
/* constraints set out above.                                       */
/*                                                                  */
/* Dr Brian Gladman (gladman@seven77.demon.co.uk) 15th July 1998    */
/*                                                                  */

typedef	long			s4byte;	/* a 32 bit signed integer type		*/
typedef	unsigned long	u4byte;	/* a 32 bit unsigned integer type	*/

static u4byte s_box[] = 
{
	0x09d0c479, 0x28c8ffe0, 0x84aa6c39, 0x9dad7287,	/* 0x000	*/
	0x7dff9be3, 0xd4268361, 0xc96da1d4, 0x7974cc93, 
	0x85d0582e, 0x2a4b5705, 0x1ca16a62, 0xc3bd279d, 
	0x0f1f25e5, 0x5160372f, 0xc695c1fb, 0x4d7ff1e4, 
	0xae5f6bf4, 0x0d72ee46, 0xff23de8a, 0xb1cf8e83, /* 0x010	*/
	0xf14902e2, 0x3e981e42, 0x8bf53eb6, 0x7f4bf8ac, 
	0x83631f83, 0x25970205, 0x76afe784, 0x3a7931d4, 
	0x4f846450, 0x5c64c3f6, 0x210a5f18, 0xc6986a26, 
	0x28f4e826, 0x3a60a81c, 0xd340a664, 0x7ea820c4, /* 0x020	*/
	0x526687c5, 0x7eddd12b, 0x32a11d1d, 0x9c9ef086, 
	0x80f6e831, 0xab6f04ad, 0x56fb9b53, 0x8b2e095c, 
	0xb68556ae, 0xd2250b0d, 0x294a7721, 0xe21fb253, 
	0xae136749, 0xe82aae86, 0x93365104, 0x99404a66, /* 0x030	*/
	0x78a784dc, 0xb69ba84b, 0x04046793, 0x23db5c1e, 
	0x46cae1d6, 0x2fe28134, 0x5a223942, 0x1863cd5b, 
	0xc190c6e3, 0x07dfb846, 0x6eb88816, 0x2d0dcc4a, 
	0xa4ccae59, 0x3798670d, 0xcbfa9493, 0x4f481d45, /* 0x040	*/
	0xeafc8ca8, 0xdb1129d6, 0xb0449e20, 0x0f5407fb, 
	0x6167d9a8, 0xd1f45763, 0x4daa96c3, 0x3bec5958, 
	0xababa014, 0xb6ccd201, 0x38d6279f, 0x02682215, 
	0x8f376cd5, 0x092c237e, 0xbfc56593, 0x32889d2c, /* 0x050	*/
	0x854b3e95, 0x05bb9b43, 0x7dcd5dcd, 0xa02e926c, 
	0xfae527e5, 0x36a1c330, 0x3412e1ae, 0xf257f462, 
	0x3c4f1d71, 0x30a2e809, 0x68e5f551, 0x9c61ba44, 
	0x5ded0ab8, 0x75ce09c8, 0x9654f93e, 0x698c0cca, /* 0x060	*/
	0x243cb3e4, 0x2b062b97, 0x0f3b8d9e, 0x00e050df, 
	0xfc5d6166, 0xe35f9288, 0xc079550d, 0x0591aee8, 
	0x8e531e74, 0x75fe3578, 0x2f6d829a, 0xf60b21ae, 
	0x95e8eb8d, 0x6699486b, 0x901d7d9b, 0xfd6d6e31,	/* 0x070	*/ 
	0x1090acef, 0xe0670dd8, 0xdab2e692, 0xcd6d4365, 
	0xe5393514, 0x3af345f0, 0x6241fc4d, 0x460da3a3, 
	0x7bcf3729, 0x8bf1d1e0, 0x14aac070, 0x1587ed55, 
	0x3afd7d3e, 0xd2f29e01, 0x29a9d1f6, 0xefb10c53, /* 0x080	*/
	0xcf3b870f, 0xb414935c, 0x664465ed, 0x024acac7, 
	0x59a744c1, 0x1d2936a7, 0xdc580aa6, 0xcf574ca8, 
	0x040a7a10, 0x6cd81807, 0x8a98be4c, 0xaccea063, 
	0xc33e92b5, 0xd1e0e03d, 0xb322517e, 0x2092bd13, /* 0x090	*/
	0x386b2c4a, 0x52e8dd58, 0x58656dfb, 0x50820371,	
	0x41811896, 0xe337ef7e, 0xd39fb119, 0xc97f0df6, 
	0x68fea01b, 0xa150a6e5, 0x55258962, 0xeb6ff41b, 
	0xd7c9cd7a, 0xa619cd9e, 0xbcf09576, 0x2672c073, /* 0x0a0	*/
	0xf003fb3c, 0x4ab7a50b, 0x1484126a, 0x487ba9b1, 
	0xa64fc9c6, 0xf6957d49, 0x38b06a75, 0xdd805fcd, 
	0x63d094cf, 0xf51c999e, 0x1aa4d343, 0xb8495294, 
	0xce9f8e99, 0xbffcd770, 0xc7c275cc, 0x378453a7, /* 0x0b0	*/
	0x7b21be33, 0x397f41bd, 0x4e94d131, 0x92cc1f98, 
	0x5915ea51, 0x99f861b7, 0xc9980a88, 0x1d74fd5f, 
	0xb0a495f8, 0x614deed0, 0xb5778eea, 0x5941792d, 
	0xfa90c1f8, 0x33f824b4, 0xc4965372, 0x3ff6d550, /* 0x0c0	*/
	0x4ca5fec0, 0x8630e964, 0x5b3fbbd6, 0x7da26a48,
	0xb203231a, 0x04297514, 0x2d639306, 0x2eb13149, 
	0x16a45272, 0x532459a0, 0x8e5f4872, 0xf966c7d9, 
	0x07128dc0, 0x0d44db62, 0xafc8d52d, 0x06316131,	/* 0x0d0	*/ 
	0xd838e7ce, 0x1bc41d00, 0x3a2e8c0f, 0xea83837e,
	0xb984737d, 0x13ba4891, 0xc4f8b949, 0xa6d6acb3, 
	0xa215cdce, 0x8359838b, 0x6bd1aa31, 0xf579dd52, 
	0x21b93f93, 0xf5176781, 0x187dfdde, 0xe94aeb76,	/* 0x0e0	*/ 
	0x2b38fd54, 0x431de1da, 0xab394825, 0x9ad3048f,
	0xdfea32aa, 0x659473e3, 0x623f7863, 0xf3346c59, 
	0xab3ab685, 0x3346a90b, 0x6b56443e, 0xc6de01f8, 
	0x8d421fc0, 0x9b0ed10c, 0x88f1a1e9, 0x54c1f029,	/* 0x0f0	*/ 
	0x7dead57b, 0x8d7ba426, 0x4cf5178a, 0x551a7cca, 
	0x1a9a5f08, 0xfcd651b9, 0x25605182, 0xe11fc6c3, 
	0xb6fd9676, 0x337b3027, 0xb7c8eb14, 0x9e5fd030,

    0x6b57e354, 0xad913cf7, 0x7e16688d, 0x58872a69,	/* 0x100	*/
	0x2c2fc7df, 0xe389ccc6, 0x30738df1, 0x0824a734, 
	0xe1797a8b, 0xa4a8d57b, 0x5b5d193b, 0xc8a8309b, 
	0x73f9a978, 0x73398d32, 0x0f59573e, 0xe9df2b03, 
	0xe8a5b6c8, 0x848d0704, 0x98df93c2, 0x720a1dc3,	/* 0x110	*/ 
	0x684f259a, 0x943ba848, 0xa6370152, 0x863b5ea3, 
	0xd17b978b, 0x6d9b58ef, 0x0a700dd4, 0xa73d36bf, 
	0x8e6a0829, 0x8695bc14, 0xe35b3447, 0x933ac568, 
	0x8894b022, 0x2f511c27, 0xddfbcc3c, 0x006662b6, /* 0x120	*/
	0x117c83fe, 0x4e12b414, 0xc2bca766, 0x3a2fec10, 
	0xf4562420, 0x55792e2a, 0x46f5d857, 0xceda25ce, 
	0xc3601d3b, 0x6c00ab46, 0xefac9c28, 0xb3c35047, 
	0x611dfee3, 0x257c3207, 0xfdd58482, 0x3b14d84f, /* 0x130	*/
	0x23becb64, 0xa075f3a3, 0x088f8ead, 0x07adf158, 
	0x7796943c, 0xfacabf3d, 0xc09730cd, 0xf7679969, 
	0xda44e9ed, 0x2c854c12, 0x35935fa3, 0x2f057d9f, 
	0x690624f8, 0x1cb0bafd, 0x7b0dbdc6, 0x810f23bb, /* 0x140	*/
	0xfa929a1a, 0x6d969a17, 0x6742979b, 0x74ac7d05, 
	0x010e65c4, 0x86a3d963, 0xf907b5a0, 0xd0042bd3, 
	0x158d7d03, 0x287a8255, 0xbba8366f, 0x096edc33, 
	0x21916a7b, 0x77b56b86, 0x951622f9, 0xa6c5e650, /* 0x150	*/
	0x8cea17d1, 0xcd8c62bc, 0xa3d63433, 0x358a68fd, 
	0x0f9b9d3c, 0xd6aa295b, 0xfe33384a, 0xc000738e, 
	0xcd67eb2f, 0xe2eb6dc2, 0x97338b02, 0x06c9f246, 
	0x419cf1ad, 0x2b83c045, 0x3723f18a, 0xcb5b3089, /* 0x160	*/
	0x160bead7, 0x5d494656, 0x35f8a74b, 0x1e4e6c9e,	
	0x000399bd, 0x67466880, 0xb4174831, 0xacf423b2, 
	0xca815ab3, 0x5a6395e7, 0x302a67c5, 0x8bdb446b, 
	0x108f8fa4, 0x10223eda, 0x92b8b48b, 0x7f38d0ee, /* 0x170	*/
	0xab2701d4, 0x0262d415, 0xaf224a30, 0xb3d88aba, 
	0xf8b2c3af, 0xdaf7ef70, 0xcc97d3b7, 0xe9614b6c, 
	0x2baebff4, 0x70f687cf, 0x386c9156, 0xce092ee5, 
	0x01e87da6, 0x6ce91e6a, 0xbb7bcc84, 0xc7922c20, /* 0x180	*/
	0x9d3b71fd, 0x060e41c6, 0xd7590f15, 0x4e03bb47, 
	0x183c198e, 0x63eeb240, 0x2ddbf49a, 0x6d5cba54, 
	0x923750af, 0xf9e14236, 0x7838162b, 0x59726c72, 
	0x81b66760, 0xbb2926c1, 0x48a0ce0d, 0xa6c0496d, /* 0x190	*/
	0xad43507b, 0x718d496a, 0x9df057af, 0x44b1bde6, 
	0x054356dc, 0xde7ced35, 0xd51a138b, 0x62088cc9, 
	0x35830311, 0xc96efca2, 0x686f86ec, 0x8e77cb68, 
	0x63e1d6b8, 0xc80f9778, 0x79c491fd, 0x1b4c67f2, /* 0x1a0	*/
	0x72698d7d, 0x5e368c31, 0xf7d95e2e, 0xa1d3493f,
    0xdcd9433e, 0x896f1552, 0x4bc4ca7a, 0xa6d1baf4, 
	0xa5a96dcc, 0x0bef8b46, 0xa169fda7, 0x74df40b7, 
	0x4e208804, 0x9a756607, 0x038e87c8, 0x20211e44,	/* 0x1b0	*/ 
	0x8b7ad4bf, 0xc6403f35, 0x1848e36d, 0x80bdb038, 
	0x1e62891c, 0x643d2107, 0xbf04d6f8, 0x21092c8c, 
	0xf644f389, 0x0778404e, 0x7b78adb8, 0xa2c52d53, 
	0x42157abe, 0xa2253e2e, 0x7bf3f4ae, 0x80f594f9, /* 0x1c0	*/
	0x953194e7, 0x77eb92ed, 0xb3816930, 0xda8d9336, 
	0xbf447469, 0xf26d9483, 0xee6faed5, 0x71371235, 
	0xde425f73, 0xb4e59f43, 0x7dbe2d4e, 0x2d37b185, 
	0x49dc9a63, 0x98c39d98, 0x1301c9a2, 0x389b1bbf, /* 0x1d0	*/
	0x0c18588d, 0xa421c1ba, 0x7aa3865c, 0x71e08558, 
	0x3c5cfcaa, 0x7d239ca4, 0x0297d9dd, 0xd7dc2830, 
	0x4b37802b, 0x7428ab54, 0xaeee0347, 0x4b3fbb85, 
	0x692f2f08, 0x134e578e, 0x36d9e0bf, 0xae8b5fcf, /* 0x1e0	*/
	0xedb93ecf, 0x2b27248e, 0x170eb1ef, 0x7dc57fd6, 
	0x1e760f16, 0xb1136601, 0x864e1b9b, 0xd7ea7319, 
	0x3ab871bd, 0xcfa4d76f, 0xe31bd782, 0x0dbeb469, 
	0xabb96061, 0x5370f85d, 0xffb07e37, 0xda30d0fb, /* 0x1f0	*/
	0xebc977b6, 0x0b98b40f, 0x3a4d0fe6, 0xdf4fc26b, 
	0x159cf22a, 0xc298d6e2, 0x2b78ef6a, 0x61a94ac0, 
	0xab561187, 0x14eea0f0, 0xdf0d4164, 0x19af70ee
};

static u4byte vk[47] =
{ 
	0x09d0c479, 0x28c8ffe0, 0x84aa6c39, 0x9dad7287, 0x7dff9be3, 0xd4268361,
	0xc96da1d4
};

static u4byte	l_key[40];

#define rotr(x,n)	(((x) >> (n)) | ((x) << (32 - (n))))
#define rotl(x,n)	(((x) << (n)) | ((x) >> (32 - (n))))
#define rotrb		t = blk[0]; blk[0] = blk[1]; blk[1] = blk[2]; blk[2] = blk[3]; blk[3] = t
#define rotlb		t = blk[3]; blk[3] = blk[2]; blk[2] = blk[1]; blk[1] = blk[0]; blk[0] = t

static void e_fun(u4byte in, u4byte key1, u4byte key2, u4byte *l, u4byte *m, u4byte *r)
{	u4byte	i;

	*m = in + key1;
	*r = rotl(in, 13) * key2;
	*l = s_box[*m & 0x000001ff];
	*r = rotl(*r, 5);
	i = *r & 0x0000001f; *m = rotl(*m, i);
	*l ^= *r;
	*r = rotl(*r, 5);
	*l ^= *r;
	i = (*r & 0x0000001f); *l = rotl(*l, i);
};

static u4byte gen_mask(u4byte x)
{	u4byte	i, m, mm;

	mm = 0x000003ff; 

	for(i = 0, m = 0; i < 23; ++i)
	{
		if(!(x & mm) || !(~x & mm))

			m |= mm;
	
		mm += mm; 
	}

	return m & (~x ^ (x << 1)) & (~x ^(x >> 1)) & 0xfffffffc; 
}

u4byte *set_key(u4byte key_blk[], u4byte key_len)
{	u4byte	i, j, u, w, *t = vk + 7;

	for(i = 0; i < 39; ++i)
	{
	  u = t[i - 7] ^ t[i - 2]; t[i] = rotl(u, 3) ^ key_blk[i % key_len] ^ i;
	}

	t[39] = key_len;

	for(j = 0; j < 7; ++j)
	{
		 for(i = 1; i < 40; ++i)
		 {
			u = t[i] + s_box[t[i - 1] & 0x000001ff]; t[i] = rotl(u, 9);
		}

		u = t[0] + s_box[t[39] & 0x000001ff]; t[0] = rotl(u, 9);
	}

	for(i = 0; i < 40; ++i)

		l_key[(7 * i) % 40] = t[i];

	for(i = 5; i < 37; i += 2)
	{
		u = s_box[265 + (l_key[i] & 0x00000003)]; j = l_key[i + 3] & 0x0000001f;

		w = l_key[i] | 0x00000003; l_key[i] = w ^ (rotl(u, j) & gen_mask(w));
	}

	return l_key;
};

void encrypt(u4byte in_blk[], u4byte out_blk[])
{	u4byte i, t, u, v, blk[4];

	blk[0] = in_blk[0] + l_key[0]; blk[1] = in_blk[1] + l_key[1];
	blk[2] = in_blk[2] + l_key[2]; blk[3] = in_blk[3] + l_key[3];

	for(i = 0; i < 8; ++i)
	{
		blk[1] ^= s_box[(blk[0] & 0x000000ff)];
		blk[1] += s_box[((blk[0] >> 8) & 0x000000ff) + 256];
		blk[2] += s_box[((blk[0] >> 16) & 0x000000ff)];
		blk[3] ^= s_box[((blk[0] >> 24) & 0x000000ff) + 256];

		blk[0] = rotr(blk[0], 24);

		if(i == 0 || i == 4)

			blk[0] += blk[3];

		if(i == 1 || i == 5)

			blk[0] += blk[1];

		rotrb;
	}

	for(i = 0; i < 16; ++i)
	{
		e_fun(blk[0], l_key[2 * i + 4], l_key[2 * i + 5], &t, &u, &v);

		blk[0] = rotl(blk[0], 13);

		blk[2] += u;

		if(i < 8)
		{
			blk[1] += t; blk[3] ^= v;
		}
		else
		{
			blk[3] += t; blk[1] ^= v;
		}

		rotrb;
	}

	for(i = 0; i < 8; ++i)
	{
		if(i == 2 || i == 6)

			blk[0] -= blk[3];

		if(i == 3 || i == 7)

			blk[0] -= blk[1];

		blk[1] ^= s_box[(blk[0] & 0x000000ff) + 256];
		blk[2] -= s_box[((blk[0] >> 24) & 0x000000ff)];
		blk[3] -= s_box[((blk[0] >> 16) & 0x000000ff) + 256];
		blk[3] ^= s_box[((blk[0] >> 8) & 0x000000ff)];

		blk[0] = rotl(blk[0], 24);

		rotrb;
	}

	out_blk[0] = blk[0] - l_key[36]; out_blk[1] = blk[1] - l_key[37];
	out_blk[2] = blk[2] - l_key[38]; out_blk[3] = blk[3] - l_key[39];
};

void decrypt(u4byte in_blk[], u4byte out_blk[])
{	
	s4byte i;
	u4byte t, u, v, blk[4];
	
	blk[0] = in_blk[0] + l_key[36]; blk[1] = in_blk[1] + l_key[37];
	blk[2] = in_blk[2] + l_key[38]; blk[3] = in_blk[3] + l_key[39];

	for(i = 0; i < 8; ++i)
	{
		rotlb;

		blk[0] = rotr(blk[0], 24);

		blk[3] ^= s_box[((blk[0] >> 8) & 0x000000ff)];
		blk[3] += s_box[((blk[0] >> 16) & 0x000000ff) + 256];
		blk[2] += s_box[((blk[0] >> 24) & 0x000000ff)];
		blk[1] ^= s_box[(blk[0] & 0x000000ff) + 256];

		if(i == 0 || i == 4)

			blk[0] += blk[1];

		if(i == 1 || i == 5)

			blk[0] += blk[3];

	}

	for(i = 0; i < 16; ++i)
	{
		rotlb;

		blk[0] = rotr(blk[0], 13);

		e_fun(blk[0], l_key[34 - 2 * i], l_key[35 - 2 * i], &t, &u, &v);

		blk[2] -= u;

		if(i < 8)
		{
			blk[3] -= t; blk[1] ^= v;
		}
		else
		{
			blk[1] -= t; blk[3] ^= v;
		}
	}

	for(i = 0; i < 8; ++i)
	{
  
		rotlb;

		if(i == 2 || i == 6)

			blk[0] -= blk[1];

		if(i == 3 || i == 7)

			blk[0] -= blk[3];


		blk[0] = rotl(blk[0], 24);

		blk[3] ^= s_box[((blk[0] >> 24) & 0x000000ff) + 256];
		blk[2] -= s_box[((blk[0] >> 16) & 0x000000ff)];
		blk[1] -= s_box[((blk[0] >> 8) & 0x000000ff) + 256];
		blk[1] ^= s_box[(blk[0] & 0x000000ff)];
	}
	
	out_blk[0] = blk[0] - l_key[0]; out_blk[1] = blk[1] - l_key[1];
	out_blk[2] = blk[2] - l_key[2]; out_blk[3] = blk[3] - l_key[3];
}