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On ancient Linux kernels, block on /dev/random before using /dev/urandom

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This commit is contained in:
Frank Denis 2016-05-15 17:18:50 +02:00
parent 1e1ba1af02
commit c752eb55d9
2 changed files with 66 additions and 0 deletions
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33
src/libsodium/randombytes/salsa20/randombytes_salsa20_random.c
View File

@ -7,6 +7,7 @@
#endif
#ifdef __linux__
# include <sys/syscall.h>
# include <poll.h>
#endif
#include <assert.h>
@ -128,6 +129,33 @@ safe_read(const int fd, void * const buf_, size_t size)
#endif
#ifndef _WIN32
# if defined(__linux__) && !defined(USE_BLOCKING_RANDOM)
static int
randombytes_block_on_dev_random(void)
{
struct pollfd pfd;
int fd;
int pret;
fd = open("/dev/random", O_RDONLY);
if (fd == -1) {
return 0;
}
pfd.fd = fd;
pfd.events = POLLIN;
pfd.revents = 0;
do {
pret = poll(&pfd, 1, -1);
} while (pret < 0 && (errno == EINTR || errno == EAGAIN));
if (pret != 1) {
(void) close(fd);
errno = EIO;
return -1;
}
return close(fd);
}
# endif
# ifndef HAVE_SAFE_ARC4RANDOM
static int
randombytes_salsa20_random_random_dev_open(void)
@ -143,6 +171,11 @@ randombytes_salsa20_random_random_dev_open(void)
const char ** device = devices;
int fd;
# if defined(__linux__) && !defined(USE_BLOCKING_RANDOM)
if (randombytes_block_on_dev_random() != 0) {
return -1;
}
# endif
do {
fd = open(*device, O_RDONLY);
if (fd != -1) {

33
src/libsodium/randombytes/sysrandom/randombytes_sysrandom.c
View File

@ -7,6 +7,7 @@
#endif
#ifdef __linux__
# include <sys/syscall.h>
# include <poll.h>
#endif
#include <assert.h>
@ -107,6 +108,33 @@ safe_read(const int fd, void * const buf_, size_t size)
#endif
#ifndef _WIN32
# if defined(__linux__) && !defined(USE_BLOCKING_RANDOM)
static int
randombytes_block_on_dev_random(void)
{
struct pollfd pfd;
int fd;
int pret;
fd = open("/dev/random", O_RDONLY);
if (fd == -1) {
return 0;
}
pfd.fd = fd;
pfd.events = POLLIN;
pfd.revents = 0;
do {
pret = poll(&pfd, 1, -1);
} while (pret < 0 && (errno == EINTR || errno == EAGAIN));
if (pret != 1) {
(void) close(fd);
errno = EIO;
return -1;
}
return close(fd);
}
# endif
static int
randombytes_sysrandom_random_dev_open(void)
{
@ -121,6 +149,11 @@ randombytes_sysrandom_random_dev_open(void)
const char ** device = devices;
int fd;
# if defined(__linux__) && !defined(USE_BLOCKING_RANDOM)
if (randombytes_block_on_dev_random() != 0) {
return -1;
}
# endif
do {
fd = open(*device, O_RDONLY);
if (fd != -1) {