diff options
Diffstat (limited to 'Python/random.c')
| -rw-r--r-- | Python/random.c | 49 |
1 files changed, 34 insertions, 15 deletions
diff --git a/Python/random.c b/Python/random.c index ea09e84..8f3e6d6 100644 --- a/Python/random.c +++ b/Python/random.c @@ -6,7 +6,9 @@ # ifdef HAVE_SYS_STAT_H # include <sys/stat.h> # endif -# ifdef HAVE_GETRANDOM_SYSCALL +# ifdef HAVE_GETRANDOM +# include <sys/random.h> +# elif defined(HAVE_GETRANDOM_SYSCALL) # include <sys/syscall.h> # endif #endif @@ -70,7 +72,9 @@ win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise) return 0; } -#elif HAVE_GETENTROPY +#elif defined(HAVE_GETENTROPY) && !defined(sun) +#define PY_GETENTROPY + /* Fill buffer with size pseudo-random bytes generated by getentropy(). Return 0 on success, or raise an exception and return -1 on error. @@ -105,16 +109,19 @@ py_getentropy(unsigned char *buffer, Py_ssize_t size, int fatal) return 0; } -#else /* !HAVE_GETENTROPY */ +#else + +#if defined(HAVE_GETRANDOM) || defined(HAVE_GETRANDOM_SYSCALL) +#define PY_GETRANDOM -#ifdef HAVE_GETRANDOM_SYSCALL static int py_getrandom(void *buffer, Py_ssize_t size, int raise) { - /* is getrandom() supported by the running kernel? - * need Linux kernel 3.17 or later */ + /* Is getrandom() supported by the running kernel? + * Need Linux kernel 3.17 or newer, or Solaris 11.3 or newer */ static int getrandom_works = 1; - /* Use /dev/urandom, block if the kernel has no entropy */ + /* Use non-blocking /dev/urandom device. On Linux at boot, the getrandom() + * syscall blocks until /dev/urandom is initialized with enough entropy. */ const int flags = 0; int n; @@ -124,7 +131,18 @@ py_getrandom(void *buffer, Py_ssize_t size, int raise) while (0 < size) { errno = 0; - /* Use syscall() because the libc doesn't expose getrandom() yet, see: +#ifdef HAVE_GETRANDOM + if (raise) { + Py_BEGIN_ALLOW_THREADS + n = getrandom(buffer, size, flags); + Py_END_ALLOW_THREADS + } + else { + n = getrandom(buffer, size, flags); + } +#else + /* On Linux, use the syscall() function because the GNU libc doesn't + * expose the Linux getrandom() syscall yet. See: * https://sourceware.org/bugzilla/show_bug.cgi?id=17252 */ if (raise) { Py_BEGIN_ALLOW_THREADS @@ -134,6 +152,7 @@ py_getrandom(void *buffer, Py_ssize_t size, int raise) else { n = syscall(SYS_getrandom, buffer, size, flags); } +#endif if (n < 0) { if (errno == ENOSYS) { @@ -182,7 +201,7 @@ dev_urandom_noraise(unsigned char *buffer, Py_ssize_t size) assert (0 < size); -#ifdef HAVE_GETRANDOM_SYSCALL +#ifdef PY_GETRANDOM if (py_getrandom(buffer, size, 0) == 1) return; /* getrandom() is not supported by the running kernel, fall back @@ -218,14 +237,14 @@ dev_urandom_python(char *buffer, Py_ssize_t size) int fd; Py_ssize_t n; struct _Py_stat_struct st; -#ifdef HAVE_GETRANDOM_SYSCALL +#ifdef PY_GETRANDOM int res; #endif if (size <= 0) return 0; -#ifdef HAVE_GETRANDOM_SYSCALL +#ifdef PY_GETRANDOM res = py_getrandom(buffer, size, 1); if (res < 0) return -1; @@ -304,7 +323,7 @@ dev_urandom_close(void) } } -#endif /* HAVE_GETENTROPY */ +#endif /* Fill buffer with pseudo-random bytes generated by a linear congruent generator (LCG): @@ -345,7 +364,7 @@ _PyOS_URandom(void *buffer, Py_ssize_t size) #ifdef MS_WINDOWS return win32_urandom((unsigned char *)buffer, size, 1); -#elif HAVE_GETENTROPY +#elif PY_GETENTROPY return py_getentropy(buffer, size, 0); #else return dev_urandom_python((char*)buffer, size); @@ -392,7 +411,7 @@ _PyRandom_Init(void) else { #ifdef MS_WINDOWS (void)win32_urandom(secret, secret_size, 0); -#elif HAVE_GETENTROPY +#elif PY_GETENTROPY (void)py_getentropy(secret, secret_size, 1); #else dev_urandom_noraise(secret, secret_size); @@ -408,7 +427,7 @@ _PyRandom_Fini(void) CryptReleaseContext(hCryptProv, 0); hCryptProv = 0; } -#elif HAVE_GETENTROPY +#elif PY_GETENTROPY /* nothing to clean */ #else dev_urandom_close(); |