/* vim: set expandtab ts=4 sw=4: */
/*
* You may redistribute this program 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.
*
* 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, see .
*/
#include "crypto/random/seed/ProcSysKernelRandomUuidRandomSeed.h"
#include "util/Identity.h"
#include "util/Bits.h"
#include "util/Hex.h"
#include
#include
#include
#include
#include
/** Number of times to try each operation. */
#define MAX_TRIES 10
static int getUUID(uint64_t output[2])
{
uint8_t buffer[40] = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
{
int fd = -1;
int tries = 0;
while ((fd = open("/proc/sys/kernel/random/uuid", O_RDONLY, 0)) < 0) {
if (++tries > MAX_TRIES || errno != EINTR) {
return -1;
}
sleep(1);
}
tries = 0;
uint8_t* buff = (uint8_t*) buffer;
int count = 37;
while (count > 0) {
int r = read(fd, buff, count);
if (r < 1) {
if (++tries > MAX_TRIES) {
break;
}
sleep(1);
continue;
}
buff += r;
count -= r;
}
close(fd);
if (count != 0) {
return -1;
}
}
// If it isn't in perfect form, fail.
if (!(buffer[8] == '-'
&& buffer[13] == '-'
&& buffer[18] == '-'
&& buffer[23] == '-'
&& buffer[36] == '\n'))
{
return -1;
}
// fold back the last 4 characters into the locations of the dashes.
buffer[8] = buffer[35];
buffer[13] = buffer[34];
buffer[18] = buffer[33];
buffer[23] = buffer[32];
buffer[32] = '\0';
if (Hex_decode((uint8_t*)output, 16, buffer, 32) != 16) {
return -1;
}
return 0;
}
static int get(RandomSeed_t* randomSeed, uint64_t output[8])
{
if (getUUID(output) || getUUID(output+2) || getUUID(output+4) || getUUID(output+6)) {
return -1;
}
return 0;
}
RandomSeed_t* ProcSysKernelRandomUuidRandomSeed_new(struct Allocator* alloc)
{
return Allocator_clone(alloc, (&(RandomSeed_t) {
.get = get,
.name = "/proc/sys/kernel/random/uuid (Linux)"
}));
}