diff options
| -rw-r--r-- | configure.ac | 1 | ||||
| -rw-r--r-- | lib/randutils.c | 69 |
2 files changed, 54 insertions, 16 deletions
diff --git a/configure.ac b/configure.ac index e0240b322..d301b3da2 100644 --- a/configure.ac +++ b/configure.ac @@ -385,6 +385,7 @@ AC_CHECK_FUNCS([ \ getdtablesize \ getexecname \ getmntinfo \ + getrandom \ getrlimit \ getsgnam \ inotify_init \ diff --git a/lib/randutils.c b/lib/randutils.c index b93b9ba47..8defe744c 100644 --- a/lib/randutils.c +++ b/lib/randutils.c @@ -25,6 +25,25 @@ #define THREAD_LOCAL static #endif +#ifdef HAVE_GETRANDOM +# include <linux/random.h> +#elif defined (__linux__) +# include <sys/syscall.h> +# if !defined(SYS_getrandom) && defined(__NR_getrandom) + /* usable kernel-headers, but old glibc-headers */ +# define SYS_getrandom __NR_getrandom +# endif +#endif + +#if !defined(HAVE_GETRANDOM) && defined(SYS_getrandom) +/* libc without function, but we have syscal */ +static int getrandom(void *buf, size_t buflen, unsigned int flags) +{ + return (syscall(SYS_getrandom, buf, buflen, flags)); +} +# define HAVE_GETRANDOM +#endif + #if defined(__linux__) && defined(__NR_gettid) && defined(HAVE_JRAND48) #define DO_JRAND_MIX THREAD_LOCAL unsigned short ul_jrand_seed[3]; @@ -35,20 +54,11 @@ int rand_get_number(int low_n, int high_n) return rand() % (high_n - low_n + 1) + low_n; } -int random_get_fd(void) +static void crank_random(void) { - int i, fd; + int i; struct timeval tv; - fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC); - if (fd == -1) - fd = open("/dev/random", O_RDONLY | O_NONBLOCK | O_CLOEXEC); - if (fd >= 0) { - i = fcntl(fd, F_GETFD); - if (i >= 0) - fcntl(fd, F_SETFD, i | FD_CLOEXEC); - } - gettimeofday(&tv, 0); srand((getpid() << 16) ^ getuid() ^ tv.tv_sec ^ tv.tv_usec); @@ -61,9 +71,23 @@ int random_get_fd(void) gettimeofday(&tv, 0); for (i = (tv.tv_sec ^ tv.tv_usec) & 0x1F; i > 0; i--) rand(); - return fd; } +int random_get_fd(void) +{ + int i, fd; + + fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC); + if (fd == -1) + fd = open("/dev/random", O_RDONLY | O_NONBLOCK | O_CLOEXEC); + if (fd >= 0) { + i = fcntl(fd, F_GETFD); + if (i >= 0) + fcntl(fd, F_SETFD, i | FD_CLOEXEC); + } + crank_random(); + return fd; +} /* * Generate a stream of random nbytes into buf. @@ -72,10 +96,19 @@ int random_get_fd(void) */ void random_get_bytes(void *buf, size_t nbytes) { - size_t i, n = nbytes; + size_t i; + unsigned char *cp = (unsigned char *)buf; + +#ifdef HAVE_GETRANDOM + while (getrandom(buf, nbytes, 0) < 0) { + if (errno == EINTR) + continue; + break; + } +#else + size_t n = nbytes; int fd = random_get_fd(); int lose_counter = 0; - unsigned char *cp = (unsigned char *) buf; if (fd >= 0) { while (n > 0) { @@ -92,11 +125,12 @@ void random_get_bytes(void *buf, size_t nbytes) close(fd); } - +#endif /* * We do this all the time, but this is the only source of * randomness if /dev/random/urandom is out to lunch. */ + crank_random(); for (cp = buf, i = 0; i < nbytes; i++) *cp++ ^= (rand() >> 7) & 0xFF; @@ -122,6 +156,9 @@ void random_get_bytes(void *buf, size_t nbytes) */ const char *random_tell_source(void) { +#ifdef HAVE_GETRANDOM + return _("getrandom() function"); +#else size_t i; static const char *random_sources[] = { "/dev/urandom", @@ -132,7 +169,7 @@ const char *random_tell_source(void) if (!access(random_sources[i], R_OK)) return random_sources[i]; } - +#endif return _("libc pseudo-random functions"); } |