/*
 * Copyright (c) 2019, Chips&Media
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "main_helper.h"

#define MD5_CBLOCK	64
#define MD5_LBLOCK	(MD5_CBLOCK/4)
#define MD5_DIGEST_LENGTH 16

#define DATA_ORDER_IS_LITTLE_ENDIAN

#define	HASH_MAKE_STRING(c,s)	do {	\
	unsigned long ll;		\
	ll=(c)->A; HOST_l2c(ll,(s));	\
	ll=(c)->B; HOST_l2c(ll,(s));	\
	ll=(c)->C; HOST_l2c(ll,(s));	\
	ll=(c)->D; HOST_l2c(ll,(s));	\
	} while (0)

#define ROTATE(a,n)     (((a)<<(n))|(((a)&0xffffffff)>>(32-(n))))

#if defined(DATA_ORDER_IS_BIG_ENDIAN)
#define HOST_c2l(c,l) \
	(l =(((unsigned long)(*((c)++)))<<24),		\
	 l|=(((unsigned long)(*((c)++)))<<16),		\
	 l|=(((unsigned long)(*((c)++)))<< 8),		\
	 l|=(((unsigned long)(*((c)++)))    ))
    
#define HOST_l2c(l,c) \
	(*((c)++)=(unsigned char)(((l)>>24)&0xff),	\
	 *((c)++)=(unsigned char)(((l)>>16)&0xff),	\
	 *((c)++)=(unsigned char)(((l)>> 8)&0xff),	\
	 *((c)++)=(unsigned char)(((l)    )&0xff))
#endif
#if defined(DATA_ORDER_IS_LITTLE_ENDIAN)
#define HOST_c2l(c,l) \
	(l =(((unsigned long)(*((c)++)))    ),		\
	 l|=(((unsigned long)(*((c)++)))<< 8),		\
	 l|=(((unsigned long)(*((c)++)))<<16),		\
	 l|=(((unsigned long)(*((c)++)))<<24))

#define HOST_l2c(l,c) \
	(*((c)++)=(unsigned char)(((l)    )&0xff),	\
	 *((c)++)=(unsigned char)(((l)>> 8)&0xff),	\
	 *((c)++)=(unsigned char)(((l)>>16)&0xff),	\
	 *((c)++)=(unsigned char)(((l)>>24)&0xff))
#endif

#define MD32_REG_T long

#define	F(b,c,d)	((((c) ^ (d)) & (b)) ^ (d))
#define	G(b,c,d)	((((b) ^ (c)) & (d)) ^ (c))
#define	H(b,c,d)	((b) ^ (c) ^ (d))
#define	I(b,c,d)	(((~(d)) | (b)) ^ (c))

#define R0(a,b,c,d,k,s,t) { \
	a+=((k)+(t)+F((b),(c),(d))); \
	a=ROTATE(a,s); \
	a+=b; };
#define R1(a,b,c,d,k,s,t) { \
	a+=((k)+(t)+G((b),(c),(d))); \
	a=ROTATE(a,s); \
	a+=b; };
#define R2(a,b,c,d,k,s,t) { \
	a+=((k)+(t)+H((b),(c),(d))); \
	a=ROTATE(a,s); \
	a+=b; };
#define R3(a,b,c,d,k,s,t) { \
	a+=((k)+(t)+I((b),(c),(d))); \
	a=ROTATE(a,s); \
	a+=b; };

void md5_block_data_order (MD5_CTX *c, const void *data_, size_t num)
{
	const unsigned char *data=data_;
	register unsigned MD32_REG_T A,B,C,D,l;
#ifndef MD32_XARRAY
	/* See comment in crypto/sha/sha_locl.h for details. */
	unsigned MD32_REG_T	XX0, XX1, XX2, XX3, XX4, XX5, XX6, XX7,
						XX8, XX9,XX10,XX11,XX12,XX13,XX14,XX15;
# define X(i)	XX##i
#else
	Uint32 XX[MD5_LBLOCK];
# define X(i)	XX[i]
#endif

	A=c->A;
	B=c->B;
	C=c->C;
	D=c->D;

	for (;num--;) {
		HOST_c2l(data,l); X( 0)=l;
		HOST_c2l(data,l); X( 1)=l;
		/* Round 0 */
		R0(A,B,C,D,X( 0), 7,0xd76aa478L);	HOST_c2l(data,l); X( 2)=l;
		R0(D,A,B,C,X( 1),12,0xe8c7b756L);	HOST_c2l(data,l); X( 3)=l;
		R0(C,D,A,B,X( 2),17,0x242070dbL);	HOST_c2l(data,l); X( 4)=l;
		R0(B,C,D,A,X( 3),22,0xc1bdceeeL);	HOST_c2l(data,l); X( 5)=l;
		R0(A,B,C,D,X( 4), 7,0xf57c0fafL);	HOST_c2l(data,l); X( 6)=l;
		R0(D,A,B,C,X( 5),12,0x4787c62aL);	HOST_c2l(data,l); X( 7)=l;
		R0(C,D,A,B,X( 6),17,0xa8304613L);	HOST_c2l(data,l); X( 8)=l;
		R0(B,C,D,A,X( 7),22,0xfd469501L);	HOST_c2l(data,l); X( 9)=l;
		R0(A,B,C,D,X( 8), 7,0x698098d8L);	HOST_c2l(data,l); X(10)=l;
		R0(D,A,B,C,X( 9),12,0x8b44f7afL);	HOST_c2l(data,l); X(11)=l;
		R0(C,D,A,B,X(10),17,0xffff5bb1L);	HOST_c2l(data,l); X(12)=l;
		R0(B,C,D,A,X(11),22,0x895cd7beL);	HOST_c2l(data,l); X(13)=l;
		R0(A,B,C,D,X(12), 7,0x6b901122L);	HOST_c2l(data,l); X(14)=l;
		R0(D,A,B,C,X(13),12,0xfd987193L);	HOST_c2l(data,l); X(15)=l;
		R0(C,D,A,B,X(14),17,0xa679438eL);
		R0(B,C,D,A,X(15),22,0x49b40821L);
		/* Round 1 */
		R1(A,B,C,D,X( 1), 5,0xf61e2562L);
		R1(D,A,B,C,X( 6), 9,0xc040b340L);
		R1(C,D,A,B,X(11),14,0x265e5a51L);
		R1(B,C,D,A,X( 0),20,0xe9b6c7aaL);
		R1(A,B,C,D,X( 5), 5,0xd62f105dL);
		R1(D,A,B,C,X(10), 9,0x02441453L);
		R1(C,D,A,B,X(15),14,0xd8a1e681L);
		R1(B,C,D,A,X( 4),20,0xe7d3fbc8L);
		R1(A,B,C,D,X( 9), 5,0x21e1cde6L);
		R1(D,A,B,C,X(14), 9,0xc33707d6L);
		R1(C,D,A,B,X( 3),14,0xf4d50d87L);
		R1(B,C,D,A,X( 8),20,0x455a14edL);
		R1(A,B,C,D,X(13), 5,0xa9e3e905L);
		R1(D,A,B,C,X( 2), 9,0xfcefa3f8L);
		R1(C,D,A,B,X( 7),14,0x676f02d9L);
		R1(B,C,D,A,X(12),20,0x8d2a4c8aL);
		/* Round 2 */
		R2(A,B,C,D,X( 5), 4,0xfffa3942L);
		R2(D,A,B,C,X( 8),11,0x8771f681L);
		R2(C,D,A,B,X(11),16,0x6d9d6122L);
		R2(B,C,D,A,X(14),23,0xfde5380cL);
		R2(A,B,C,D,X( 1), 4,0xa4beea44L);
		R2(D,A,B,C,X( 4),11,0x4bdecfa9L);
		R2(C,D,A,B,X( 7),16,0xf6bb4b60L);
		R2(B,C,D,A,X(10),23,0xbebfbc70L);
		R2(A,B,C,D,X(13), 4,0x289b7ec6L);
		R2(D,A,B,C,X( 0),11,0xeaa127faL);
		R2(C,D,A,B,X( 3),16,0xd4ef3085L);
		R2(B,C,D,A,X( 6),23,0x04881d05L);
		R2(A,B,C,D,X( 9), 4,0xd9d4d039L);
		R2(D,A,B,C,X(12),11,0xe6db99e5L);
		R2(C,D,A,B,X(15),16,0x1fa27cf8L);
		R2(B,C,D,A,X( 2),23,0xc4ac5665L);
		/* Round 3 */
		R3(A,B,C,D,X( 0), 6,0xf4292244L);
		R3(D,A,B,C,X( 7),10,0x432aff97L);
		R3(C,D,A,B,X(14),15,0xab9423a7L);
		R3(B,C,D,A,X( 5),21,0xfc93a039L);
		R3(A,B,C,D,X(12), 6,0x655b59c3L);
		R3(D,A,B,C,X( 3),10,0x8f0ccc92L);
		R3(C,D,A,B,X(10),15,0xffeff47dL);
		R3(B,C,D,A,X( 1),21,0x85845dd1L);
		R3(A,B,C,D,X( 8), 6,0x6fa87e4fL);
		R3(D,A,B,C,X(15),10,0xfe2ce6e0L);
		R3(C,D,A,B,X( 6),15,0xa3014314L);
		R3(B,C,D,A,X(13),21,0x4e0811a1L);
		R3(A,B,C,D,X( 4), 6,0xf7537e82L);
		R3(D,A,B,C,X(11),10,0xbd3af235L);
		R3(C,D,A,B,X( 2),15,0x2ad7d2bbL);
		R3(B,C,D,A,X( 9),21,0xeb86d391L);

		A = c->A += A;
		B = c->B += B;
		C = c->C += C;
		D = c->D += D;
	}
}

/* Implemented from RFC1321 The MD5 Message-Digest Algorithm
 */

#define INIT_DATA_A (unsigned long)0x67452301L
#define INIT_DATA_B (unsigned long)0xefcdab89L
#define INIT_DATA_C (unsigned long)0x98badcfeL
#define INIT_DATA_D (unsigned long)0x10325476L

Int32 MD5_Init (MD5_CTX *c)
{
	c->A=INIT_DATA_A;
	c->B=INIT_DATA_B;
	c->C=INIT_DATA_C;
	c->D=INIT_DATA_D;
	c->Nl=0;
	c->Nh=0;
	c->num=0;
	return 1;
}

Int32 MD5_Update (MD5_CTX *c, const void *data_, size_t len)
{
	const unsigned char *data=data_;
	unsigned char *p;
	Uint32 l;
	size_t n;

	if (len==0) return 1;

	l=(c->Nl+(((Uint32)len)<<3))&0xffffffffUL;
	/* 95-05-24 eay Fixed a bug with the overflow handling, thanks to
	 * Wei Dai <weidai@eskimo.com> for pointing it out. */
	if (l < c->Nl) /* overflow */
		c->Nh++;
	c->Nh+=(len>>29);	/* might cause compiler warning on 16-bit */
	c->Nl=l;

	n = c->num;
	if (n != 0) {
		p=(unsigned char *)c->data;

		if (len >= MD5_CBLOCK || len+n >= MD5_CBLOCK) {
			osal_memcpy (p+n,data,MD5_CBLOCK-n);
			md5_block_data_order (c,p,1);
			n      = MD5_CBLOCK-n;
			data  += n;
			len   -= n;
			c->num = 0;
			osal_memset (p,0,MD5_CBLOCK);	/* keep it zeroed */
		} else {
			osal_memcpy (p+n,data,len);
			c->num += (unsigned int)len;
			return 1;
		}
	}

	n = len/MD5_CBLOCK;
	if (n > 0) {
		md5_block_data_order (c,data,n);
		n    *= MD5_CBLOCK;
		data += n;//lint !e662
		len  -= n;
	}

	if (len != 0) {
		p = (unsigned char *)c->data;
		c->num = len;
		osal_memcpy (p,data,len);
	}
	return 1;
}

Int32 MD5_Final (Uint8* md, MD5_CTX *c)
{
	unsigned char *p = (unsigned char *)c->data;
	size_t n = c->num;

	p[n] = 0x80; /* there is always room for one */
	n++;

	if (n > (MD5_CBLOCK-8)) {
		osal_memset (p+n,0,MD5_CBLOCK-n);
		n=0;
		md5_block_data_order (c,p,1);
	}
	osal_memset (p+n,0,MD5_CBLOCK-8-n);

	p += MD5_CBLOCK-8;
#if   defined(DATA_ORDER_IS_BIG_ENDIAN)
	(void)HOST_l2c(c->Nh,p);
	(void)HOST_l2c(c->Nl,p);
#elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
	(void)HOST_l2c(c->Nl,p);
	(void)HOST_l2c(c->Nh,p);
#endif
	p -= MD5_CBLOCK;
	md5_block_data_order (c,p,1);
	c->num=0;
	osal_memset (p,0,MD5_CBLOCK);

	HASH_MAKE_STRING(c,md);

	return 1;
}

Uint8* MD5 (const Uint8* d, size_t n, Uint8* md)
{
	MD5_CTX c;
	static unsigned char m[MD5_DIGEST_LENGTH];

	if (md == NULL) md=m;
	if (!MD5_Init(&c))
		return NULL;
	MD5_Update(&c,d,n);
	MD5_Final(md,&c);
	return(md);
}
 
