actube/src/capwap/cw_rand.c

90 lines
1.8 KiB
C

/*
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/>.
*/
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "cw_util.h"
#include "cw_log.h"
char * cw_rand_dev = "/dev/random";
int cw_rand_r(uint8_t*dst, int len)
{
int rf;
int l;
rf = open(cw_rand_dev, O_RDONLY | O_NDELAY);
if (rf<0){
cw_log(LOG_ERR,"Can't open %s: %s",cw_rand_dev,strerror(errno));
return 0;
}
l = read(rf, dst, len);
close(rf);
if ((l<0) && (errno != EAGAIN)){
cw_log(LOG_ERR,"Cant read from %s: %s",cw_rand_dev,strerror(errno));
return 0;
}
/* if (l<len){
cw_dbg(DBG_CW_INFO,"Not enough entropy reading from %s, using pseudo rand",cw_rand_dev);
return cw_pseudo_rand(dst,len);
}
*/
return l;
}
int cw_rand(uint8_t *dst, int len)
{
static int init = 1;
if (init){
uint32_t rinit=time(NULL);
int l = cw_rand_r((uint8_t*)(&rinit),sizeof(uint32_t));
if (l<sizeof(uint32_t))
cw_dbg(DBG_CW_INFO,"Not enough entropy reading from %s, using pseudo rand",cw_rand_dev);
srand(rinit);
init =0;
}
int i;
for (i=0; i<len; i++){
dst[i]=rand();
}
return len;
}