// MIT License, Copyright (c) 2021 Marvin Borner

#include <crypto.h>
#include <def.h>
#include <mem.h>

/**
 * MD5
 */

#define MD5_LEFTROTATE(x, c) (((x) << (c)) | ((x) >> (32 - (c))))

static const u32 md5_tab[64] = {
	0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, 0xf57c0faf, 0x4787c62a, 0xa8304613,
	0xfd469501, 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be, 0x6b901122, 0xfd987193,
	0xa679438e, 0x49b40821, 0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa, 0xd62f105d,
	0x02441453, 0xd8a1e681, 0xe7d3fbc8, 0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
	0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a, 0xfffa3942, 0x8771f681, 0x6d9d6122,
	0xfde5380c, 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70, 0x289b7ec6, 0xeaa127fa,
	0xd4ef3085, 0x04881d05, 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665, 0xf4292244,
	0x432aff97, 0xab9423a7, 0xfc93a039, 0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
	0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1, 0xf7537e82, 0xbd3af235, 0x2ad7d2bb,
	0xeb86d391,
};

static const u32 md5_rounds[] = {
	7,  12, 17, 22, 7,  12, 17, 22, 7,  12, 17, 22, 7,  12, 17, 22, 5,  9,	14, 20, 5,  9,
	14, 20, 5,  9,	14, 20, 5,  9,	14, 20, 4,  11, 16, 23, 4,  11, 16, 23, 4,  11, 16, 23,
	4,  11, 16, 23, 6,  10, 15, 21, 6,  10, 15, 21, 6,  10, 15, 21, 6,  10, 15, 21,
};

static void md5_u32_to_bytes(u32 val, u8 *bytes)
{
	bytes[0] = (u8)val;
	bytes[1] = (u8)(val >> 8);
	bytes[2] = (u8)(val >> 16);
	bytes[3] = (u8)(val >> 24);
}

static u32 md5_bytes_to_u32(u8 *bytes)
{
	return (u32)bytes[0] | ((u32)bytes[1] << 8) | ((u32)bytes[2] << 16) | ((u32)bytes[3] << 24);
}

void md5(const void *initial_msg, u32 initial_len, u8 digest[16])
{
	u32 w[16] = { 0 };

	u32 h0 = 0x67452301;
	u32 h1 = 0xefcdab89;
	u32 h2 = 0x98badcfe;
	u32 h3 = 0x10325476;

	u32 new_len;
	for (new_len = initial_len + 1; new_len % (512 / 8) != 448 / 8; new_len++)
		;

	u8 *msg = malloc(new_len + 8);
	memcpy(msg, initial_msg, initial_len);
	msg[initial_len] = 0x80;
	for (u32 offset = initial_len + 1; offset < new_len; offset++)
		msg[offset] = 0;

	md5_u32_to_bytes(initial_len * 8, msg + new_len);
	md5_u32_to_bytes(initial_len >> 29, msg + new_len + 4);

	for (u32 offset = 0; offset < new_len; offset += (512 / 8)) {
		for (u32 i = 0; i < 16; i++)
			w[i] = md5_bytes_to_u32(msg + offset + i * 4);

		u32 a = h0;
		u32 b = h1;
		u32 c = h2;
		u32 d = h3;

		u32 f, g;
		for (u32 i = 0; i < 64; i++) {
			if (i < 16) {
				f = (b & c) | ((~b) & d);
				g = i;
			} else if (i < 32) {
				f = (d & b) | ((~d) & c);
				g = (5 * i + 1) % 16;
			} else if (i < 48) {
				f = b ^ c ^ d;
				g = (3 * i + 5) % 16;
			} else {
				f = c ^ (b | (~d));
				g = (7 * i) % 16;
			}

			u32 temp = d;
			d = c;
			c = b;
			b = b + MD5_LEFTROTATE((a + f + md5_tab[i] + w[g]), md5_rounds[i]);
			a = temp;
		}

		h0 += a;
		h1 += b;
		h2 += c;
		h3 += d;
	}

	free(msg);

	md5_u32_to_bytes(h0, digest);
	md5_u32_to_bytes(h1, digest + 4);
	md5_u32_to_bytes(h2, digest + 8);
	md5_u32_to_bytes(h3, digest + 12);
}

/**
 * CRC32
 */

static const u32 crc32_tab[] = {
	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535,
	0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd,
	0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d,
	0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
	0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
	0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
	0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac,
	0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
	0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab,
	0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
	0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb,
	0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
	0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea,
	0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce,
	0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
	0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
	0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409,
	0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
	0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739,
	0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
	0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2, 0x1e01f268,
	0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0,
	0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8,
	0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
	0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
	0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703,
	0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7,
	0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
	0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae,
	0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
	0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, 0x88085ae6,
	0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
	0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d,
	0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5,
	0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
	0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
};

u32 crc32(u32 crc, const void *buf, u32 size)
{
	const u8 *p = buf;
	crc = crc ^ ~0UL;

	while (size--)
		crc = crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);

	return crc ^ ~0UL;
}

#ifdef KERNEL

#include <drivers/cpu.h>
u32 crc32_user(u32 crc, const void *buf, u32 size)
{
	stac();
	u32 ret = crc32(crc, buf, size);
	clac();
	return ret;
}

#endif