ac15.c

//https://ww.reddit.com/r/cpp_questions/comments/3hf5hs/include_iostream_and_other_c_functionality_in_a_c/
static uint32_t ac15_f(uint32_t x,uint32_t k)
{
	static const uint8_t S[256] = {
	 99, 124, 119, 123, 242, 107, 111, 197,  48,   1, 103,  43, 254, 215, 171, 118,
	 202, 130, 201, 125, 250,  89,  71, 240, 173, 212, 162, 175, 156, 164, 114, 192,
	 183, 253, 147,  38,  54,  63, 247, 204,  52, 165, 229, 241, 113, 216,  49,  21,
	  4, 199,  35, 195,  24, 150,   5, 154,   7,  18, 128, 226, 235,  39, 178, 117,
	  9, 131,  44,  26,  27, 110,  90, 160,  82,  59, 214, 179,  41, 227,  47, 132,
	 83, 209,   32, 237,  0, 252, 177,  91, 106, 203, 190,  57,  74,  76,  88, 207,
	 208, 239, 170, 251,  77,  67,  51, 133,  69, 249,   2, 127, 80, 60, 159, 168,
	 81, 163,  64, 143, 146, 157,  56, 245, 188, 182, 218,  33,  16, 255, 243, 210,
	 205,  12,  19, 236,  95, 166,  68,  23, 196, 167, 126,  61, 100, 93,  25, 115,
	 96, 129,  79, 220,  34,  42, 144, 136,  70, 238, 184,  20, 233,  94,  11, 219,
	 224,  50,  58,  10,  73,   6,  36,  92, 194, 211, 172,  98, 145, 149, 228, 121,
	 231, 120,  55, 109, 141, 213,  78, 169, 108,  86,244, 234, 101, 122, 174,   8,
	 186, 200,  37,  46,  28, 151, 180, 198, 232, 221, 116,  31,  75, 189, 139, 138,
	 112,  62, 181, 102, 72,   3, 246,  14,  97,  53,  87, 185, 134, 193,  29, 158,
	 225, 248, 152,  17, 105, 217, 142, 148, 155,  30, 135, 222, 206,  85, 40, 140,
	 223, 161, 137,  13, 191, 230,  66, 104,  65, 153,  45,15, 176,  84, 187,  22
	};
	
	uint32_t z=0;
	uint8_t Xo=x & 0xFF;
	for(uint_fast8_t i=3;i>=0;--i)
	{
		uint8_t X=(x>>(i*8)) & 0xFF;
		uint8_t Y=S[X];
		uint8_t K=(k>>(i*8)) & 0xFF;
		z<<=8;
		z|=K&Y | Y&X | X&K;
		Xo=X;
	}
	return (z >> 2) | (z << 30);  //circrshift
}

void ac15_schedule_key(uint32_t* key_out,size_t key_length,uint64_t key_in)
{
	uint32_t left,right;
	left=(key_in >> 32);
	right=key_in & 0xFFFFFFFF;
	for(size_t ki=0;ki<key_length;ki++)
	{
		left+=ac15_f(right,right); 
		
		key_out[ki]=left;
		
		uint32_t tmp=left;
		left=right;
		right=tmp;
	}
}

uint64_t ac15_encrypt_block(uint64_t block_in,const uint32_t key*,size_t key_length)
{
	uint32_t left,right;
	left=(block_in >> 32);
	right=block_in & 0xFFFFFFFF;
	for(size_t ki=0;ki<key_length;ki++)
	{
		left+=ac15_f(right,key[ki]);
		
		uint32_t tmp=left;
		left=right;
		right=tmp;
	}
	uint64_t block_out=(left << 32) | right;
	return (block_out >> 16) | (block_out << 48); //circrshift
}