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- /* 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 <https://www.gnu.org/licenses/>.
- */
- #include "crypto/random/seed/ProcSysKernelRandomUuidRandomSeed.h"
- #include "util/Identity.h"
- #include "util/Bits.h"
- #include "util/Hex.h"
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <fcntl.h>
- #include <unistd.h>
- #include <errno.h>
- /** 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)"
- }));
- }
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