#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//#include <openssl/md2.h>
//#include <openssl/opensslv.h>
//#include <openssl/crypto.h>
#include "md2.h"

//const char *MD2_version="MD2" OPENSSL_VERSION_PTEXT;

/* Implemented from RFC1319 The MD2 Message-Digest Algorithm
 */

#define UCHAR	unsigned char

static void md2_block(MD2_CTX *c, const unsigned char *d);
/* The magic S table - I have converted it to hex since it is
 * basically just a random byte string. */
static const MD2_INT S[256]={
	0x29, 0x2E, 0x43, 0xC9, 0xA2, 0xD8, 0x7C, 0x01,
	0x3D, 0x36, 0x54, 0xA1, 0xEC, 0xF0, 0x06, 0x13,
	0x62, 0xA7, 0x05, 0xF3, 0xC0, 0xC7, 0x73, 0x8C,
	0x98, 0x93, 0x2B, 0xD9, 0xBC, 0x4C, 0x82, 0xCA,
	0x1E, 0x9B, 0x57, 0x3C, 0xFD, 0xD4, 0xE0, 0x16,
	0x67, 0x42, 0x6F, 0x18, 0x8A, 0x17, 0xE5, 0x12,
	0xBE, 0x4E, 0xC4, 0xD6, 0xDA, 0x9E, 0xDE, 0x49,
	0xA0, 0xFB, 0xF5, 0x8E, 0xBB, 0x2F, 0xEE, 0x7A,
	0xA9, 0x68, 0x79, 0x91, 0x15, 0xB2, 0x07, 0x3F,
	0x94, 0xC2, 0x10, 0x89, 0x0B, 0x22, 0x5F, 0x21,
	0x80, 0x7F, 0x5D, 0x9A, 0x5A, 0x90, 0x32, 0x27,
	0x35, 0x3E, 0xCC, 0xE7, 0xBF, 0xF7, 0x97, 0x03,
	0xFF, 0x19, 0x30, 0xB3, 0x48, 0xA5, 0xB5, 0xD1,
	0xD7, 0x5E, 0x92, 0x2A, 0xAC, 0x56, 0xAA, 0xC6,
	0x4F, 0xB8, 0x38, 0xD2, 0x96, 0xA4, 0x7D, 0xB6,
	0x76, 0xFC, 0x6B, 0xE2, 0x9C, 0x74, 0x04, 0xF1,
	0x45, 0x9D, 0x70, 0x59, 0x64, 0x71, 0x87, 0x20,
	0x86, 0x5B, 0xCF, 0x65, 0xE6, 0x2D, 0xA8, 0x02,
	0x1B, 0x60, 0x25, 0xAD, 0xAE, 0xB0, 0xB9, 0xF6,
	0x1C, 0x46, 0x61, 0x69, 0x34, 0x40, 0x7E, 0x0F,
	0x55, 0x47, 0xA3, 0x23, 0xDD, 0x51, 0xAF, 0x3A,
	0xC3, 0x5C, 0xF9, 0xCE, 0xBA, 0xC5, 0xEA, 0x26,
	0x2C, 0x53, 0x0D, 0x6E, 0x85, 0x28, 0x84, 0x09,
	0xD3, 0xDF, 0xCD, 0xF4, 0x41, 0x81, 0x4D, 0x52,
	0x6A, 0xDC, 0x37, 0xC8, 0x6C, 0xC1, 0xAB, 0xFA,
	0x24, 0xE1, 0x7B, 0x08, 0x0C, 0xBD, 0xB1, 0x4A,
	0x78, 0x88, 0x95, 0x8B, 0xE3, 0x63, 0xE8, 0x6D,
	0xE9, 0xCB, 0xD5, 0xFE, 0x3B, 0x00, 0x1D, 0x39,
	0xF2, 0xEF, 0xB7, 0x0E, 0x66, 0x58, 0xD0, 0xE4,
	0xA6, 0x77, 0x72, 0xF8, 0xEB, 0x75, 0x4B, 0x0A,
	0x31, 0x44, 0x50, 0xB4, 0x8F, 0xED, 0x1F, 0x1A,
	0xDB, 0x99, 0x8D, 0x33, 0x9F, 0x11, 0x83, 0x14,
	};

const char *MD2_options(void)
	{
	if (sizeof(MD2_INT) == 1)
		return("md2(char)");
	else
		return("md2(int)");
	}

int MD2_Init(MD2_CTX *c)
	{
	c->num=0;
	memset(c->state,0,sizeof c->state);
	memset(c->cksm,0,sizeof c->cksm);
	memset(c->data,0,sizeof c->data);
	return 1;
	}

int MD2_Update(MD2_CTX *c, const unsigned char *data, size_t len)
	{
	register UCHAR *p;

	if (len == 0) return 1;

	p=c->data;
	if (c->num != 0)
		{
		if ((c->num+len) >= MD2_BLOCK)
			{
			memcpy(&(p[c->num]),data,MD2_BLOCK-c->num);
			md2_block(c,c->data);
			data+=(MD2_BLOCK - c->num);
			len-=(MD2_BLOCK - c->num);
			c->num=0;
			/* drop through and do the rest */
			}
		else
			{
			memcpy(&(p[c->num]),data,len);
			/* data+=len; */
			c->num+=(int)len;
			return 1;
			}
		}
	/* we now can process the input data in blocks of MD2_BLOCK
	 * chars and save the leftovers to c->data. */
	while (len >= MD2_BLOCK)
		{
		md2_block(c,data);
		data+=MD2_BLOCK;
		len-=MD2_BLOCK;
		}
	memcpy(p,data,len);
	c->num=(int)len;
	return 1;
	}

static void md2_block(MD2_CTX *c, const unsigned char *d)
	{
	register MD2_INT t,*sp1,*sp2;
	register int i,j;
	MD2_INT state[48];

	sp1=c->state;
	sp2=c->cksm;
	j=sp2[MD2_BLOCK-1];
	for (i=0; i<16; i++)
		{
		state[i]=sp1[i];
		state[i+16]=t=d[i];
		state[i+32]=(t^sp1[i]);
		j=sp2[i]^=S[t^j];
		}
	t=0;
	for (i=0; i<18; i++)
		{
		for (j=0; j<48; j+=8)
			{
			t= state[j+ 0]^=S[t];
			t= state[j+ 1]^=S[t];
			t= state[j+ 2]^=S[t];
			t= state[j+ 3]^=S[t];
			t= state[j+ 4]^=S[t];
			t= state[j+ 5]^=S[t];
			t= state[j+ 6]^=S[t];
			t= state[j+ 7]^=S[t];
			}
		t=(t+i)&0xff;
		}
	memcpy(sp1,state,16*sizeof(MD2_INT));
	//OPENSSL_cleanse(state,48*sizeof(MD2_INT));
	}

int MD2_Final(unsigned char *md, MD2_CTX *c)
	{
	int i,v;
	register UCHAR *cp;
	register MD2_INT *p1,*p2;

	cp=c->data;
	p1=c->state;
	p2=c->cksm;
	v=MD2_BLOCK-c->num;
	for (i=c->num; i<MD2_BLOCK; i++)
		cp[i]=(UCHAR)v;

	md2_block(c,cp);

	for (i=0; i<MD2_BLOCK; i++)
		cp[i]=(UCHAR)p2[i];
	md2_block(c,cp);

	for (i=0; i<16; i++)
		md[i]=(UCHAR)(p1[i]&0xff);
	memset((char *)&c,0,sizeof(c));
	return 1;
	}