/*
 *  md5.c
 *  Adapted for perf_index from ccmd5_ltc.c in corecrypto
 *
 *  Created by Fabrice Gautier on 12/3/10.
 *  Copyright 2010,2011 Apple Inc. All rights reserved.
 *
 */

#include "md5.h"

#include <stdint.h>
#include <string.h>

#define CCMD5_BLOCK_SIZE 64

#define F(x, y, z)  (z ^ (x & (y ^ z)))
#define G(x, y, z)  (y ^ (z & (y ^ x)))
#define H(x, y, z)  (x^y^z)
#define I(x, y, z)  (y^(x|(~z)))

#define CC_ROLc(X, s) (((X) << (s)) | ((X) >> (32 - (s))))

#define FF(a, b, c, d, M, s, t) \
a = (a + F(b,c,d) + M + t); a = CC_ROLc(a, s) + b;

#define GG(a, b, c, d, M, s, t) \
a = (a + G(b,c,d) + M + t); a = CC_ROLc(a, s) + b;

#define HH(a, b, c, d, M, s, t) \
a = (a + H(b,c,d) + M + t); a = CC_ROLc(a, s) + b;

#define II(a, b, c, d, M, s, t) \
a = (a + I(b,c,d) + M + t); a = CC_ROLc(a, s) + b;

static void
md5_compress(uint32_t *state, unsigned long nblocks, const void *in)
{
	uint32_t i, W[16], a, b, c, d;
	uint32_t *s = state;
	const unsigned char *buf = in;

	while (nblocks--) {
		/* copy the state into 512-bits into W[0..15] */
		for (i = 0; i < 16; i++) {
			W[i] = ((uint32_t*)buf)[i];
		}

		/* copy state */
		a = s[0];
		b = s[1];
		c = s[2];
		d = s[3];

		FF(a, b, c, d, W[0], 7, 0xd76aa478)
		FF(d, a, b, c, W[1], 12, 0xe8c7b756)
		FF(c, d, a, b, W[2], 17, 0x242070db)
		FF(b, c, d, a, W[3], 22, 0xc1bdceee)
		FF(a, b, c, d, W[4], 7, 0xf57c0faf)
		FF(d, a, b, c, W[5], 12, 0x4787c62a)
		FF(c, d, a, b, W[6], 17, 0xa8304613)
		FF(b, c, d, a, W[7], 22, 0xfd469501)
		FF(a, b, c, d, W[8], 7, 0x698098d8)
		FF(d, a, b, c, W[9], 12, 0x8b44f7af)
		FF(c, d, a, b, W[10], 17, 0xffff5bb1)
		FF(b, c, d, a, W[11], 22, 0x895cd7be)
		FF(a, b, c, d, W[12], 7, 0x6b901122)
		FF(d, a, b, c, W[13], 12, 0xfd987193)
		FF(c, d, a, b, W[14], 17, 0xa679438e)
		FF(b, c, d, a, W[15], 22, 0x49b40821)
		GG(a, b, c, d, W[1], 5, 0xf61e2562)
		GG(d, a, b, c, W[6], 9, 0xc040b340)
		GG(c, d, a, b, W[11], 14, 0x265e5a51)
		GG(b, c, d, a, W[0], 20, 0xe9b6c7aa)
		GG(a, b, c, d, W[5], 5, 0xd62f105d)
		GG(d, a, b, c, W[10], 9, 0x02441453)
		GG(c, d, a, b, W[15], 14, 0xd8a1e681)
		GG(b, c, d, a, W[4], 20, 0xe7d3fbc8)
		GG(a, b, c, d, W[9], 5, 0x21e1cde6)
		GG(d, a, b, c, W[14], 9, 0xc33707d6)
		GG(c, d, a, b, W[3], 14, 0xf4d50d87)
		GG(b, c, d, a, W[8], 20, 0x455a14ed)
		GG(a, b, c, d, W[13], 5, 0xa9e3e905)
		GG(d, a, b, c, W[2], 9, 0xfcefa3f8)
		GG(c, d, a, b, W[7], 14, 0x676f02d9)
		GG(b, c, d, a, W[12], 20, 0x8d2a4c8a)
		HH(a, b, c, d, W[5], 4, 0xfffa3942)
		HH(d, a, b, c, W[8], 11, 0x8771f681)
		HH(c, d, a, b, W[11], 16, 0x6d9d6122)
		HH(b, c, d, a, W[14], 23, 0xfde5380c)
		HH(a, b, c, d, W[1], 4, 0xa4beea44)
		HH(d, a, b, c, W[4], 11, 0x4bdecfa9)
		HH(c, d, a, b, W[7], 16, 0xf6bb4b60)
		HH(b, c, d, a, W[10], 23, 0xbebfbc70)
		HH(a, b, c, d, W[13], 4, 0x289b7ec6)
		HH(d, a, b, c, W[0], 11, 0xeaa127fa)
		HH(c, d, a, b, W[3], 16, 0xd4ef3085)
		HH(b, c, d, a, W[6], 23, 0x04881d05)
		HH(a, b, c, d, W[9], 4, 0xd9d4d039)
		HH(d, a, b, c, W[12], 11, 0xe6db99e5)
		HH(c, d, a, b, W[15], 16, 0x1fa27cf8)
		HH(b, c, d, a, W[2], 23, 0xc4ac5665)
		II(a, b, c, d, W[0], 6, 0xf4292244)
		II(d, a, b, c, W[7], 10, 0x432aff97)
		II(c, d, a, b, W[14], 15, 0xab9423a7)
		II(b, c, d, a, W[5], 21, 0xfc93a039)
		II(a, b, c, d, W[12], 6, 0x655b59c3)
		II(d, a, b, c, W[3], 10, 0x8f0ccc92)
		II(c, d, a, b, W[10], 15, 0xffeff47d)
		II(b, c, d, a, W[1], 21, 0x85845dd1)
		II(a, b, c, d, W[8], 6, 0x6fa87e4f)
		II(d, a, b, c, W[15], 10, 0xfe2ce6e0)
		II(c, d, a, b, W[6], 15, 0xa3014314)
		II(b, c, d, a, W[13], 21, 0x4e0811a1)
		II(a, b, c, d, W[4], 6, 0xf7537e82)
		II(d, a, b, c, W[11], 10, 0xbd3af235)
		II(c, d, a, b, W[2], 15, 0x2ad7d2bb)
		II(b, c, d, a, W[9], 21, 0xeb86d391)

		/* store state */
		s[0] += a;
		s[1] += b;
		s[2] += c;
		s[3] += d;

		buf += CCMD5_BLOCK_SIZE;
	}
}

void
md5_hash(uint8_t *message, uint64_t len, uint32_t *hash)
{
	hash[0] = 0x67452301;
	hash[1] = 0xEFCDAB89;
	hash[2] = 0x98BADCFE;
	hash[3] = 0x10325476;

	md5_compress(hash, len / 64, message);

	uint32_t blockbuff[16];
	uint8_t *byteptr = (uint8_t*)blockbuff;

	int left = len % 64;
	memcpy(byteptr, message + len - left, left);

	byteptr[left] = 0x80;
	left++;
	if (64 - left >= 8) {
		bzero(byteptr + left, 56 - left);
	} else {
		memset(byteptr + left, 0, 64 - left);
		md5_compress(hash, 1, blockbuff);
		bzero(blockbuff, 56);
	}
	blockbuff[14] = (uint32_t)(len << 3);
	blockbuff[15] = (uint32_t)(len >> 29);
	md5_compress(hash, 1, blockbuff);
}