actube/src/cw/md5sum.c

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/*
This file is part of libcapwap.
libcapwap 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 3 of the License, or
(at your option) any later version.
libcapwap 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 Foobar. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file
* @brief
*/
#include <stdio.h>
#include <errno.h>
#include <nettle/md5.h>
#include "capwap_crypto.h"
#define BLOCK_SIZE 4096
/**
* Calculate MD5 checksum for an opened file.
* @param digest destination buffer for calculated
* checksum (16 bytes, for a predifned constant use #CW_MD5_DIGEST_SIZE)
* @param infile file hanle
*
* Remember to set the file pointer to the beginning of the file, before
* calling this function. Therefore use fseek(file,0,SEEK_SET).
*/
int cw_fgetmd5sum ( uint8_t *digest, FILE *infile )
{
struct md5_ctx ctx;
uint8_t buffer[BLOCK_SIZE];
md5_init ( &ctx );
while ( !feof ( infile ) ) {
int bytes = fread ( buffer, 1, sizeof ( buffer ), infile );
md5_update ( &ctx, bytes, buffer );
}
if ( ferror ( infile ) )
return errno;
md5_digest ( &ctx, MD5_DIGEST_SIZE, digest );
return 0;
}