/*
   Copyright (C) Andrew Tridgell 2002
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
  simple front-end functions to mdfour code
*/

#include "ccache.h"
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>

static MD4_CTX md;
static off_t   totalN;

void hash_buffer(const unsigned char *s, unsigned int len)
{
       totalN += len;
       MD4Update(&md, s, len);
}

void hash_start(void)
{
	MD4Init(&md);
}

void hash_string(const char *s)
{
	hash_buffer(s, strlen(s));
}

void hash_int(int x)
{
	hash_buffer((char *)&x, sizeof(x));
}

/* add contents of a file to the hash */
void hash_file(const char *fname)
{
       char *buf;
       int fd;
       struct stat stats;

	fd = open(fname, O_RDONLY|O_BINARY);
	if (fd == -1) {
		cc_log("Failed to open %s\n", fname);
                fatal(__FUNCTION__);
	}

       if (fstat(fd, &stats) != 0) {
               cc_log("Failed to fstat the opened %s (descriptor %d)\n",
                       fname, fd);
               close(fd);
               fatal(__FUNCTION__);
       }
       buf = mmap(NULL, stats.st_size, PROT_READ, MAP_PRIVATE, fd, 0); 
       if (buf == MAP_FAILED) {
               cc_log("Failed to mmap %s\n", fname);
               close(fd);
               fatal(__FUNCTION__);
        }       

        hash_buffer(buf, stats.st_size);
	close(fd);
}

/* return the hash result as a static string */
char *hash_result(void)
{
	static char ret[53];

        MD4End(&md, ret);
	
        snprintf(ret + 32, sizeof ret - 32, "-%lu", (unsigned long)totalN);
	return ret;
}