use getentropy when available (backport of 75ede5bec8db) (closes #23115)
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 023ebf4..e84f457 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -9,6 +9,7 @@
import sys
import signal
import subprocess
+import sysconfig
import time
try:
import resource
@@ -567,6 +568,12 @@
data2 = self.get_urandom_subprocess(16)
self.assertNotEqual(data1, data2)
+
+HAVE_GETENTROPY = (sysconfig.get_config_var('HAVE_GETENTROPY') == 1)
+
+@unittest.skipIf(HAVE_GETENTROPY,
+ "getentropy() does not use a file descriptor")
+class URandomFDTests(unittest.TestCase):
@unittest.skipUnless(resource, "test requires the resource module")
def test_urandom_failure(self):
# Check urandom() failing when it is not able to open /dev/random.
diff --git a/Misc/NEWS b/Misc/NEWS
index b204aeb..276b537 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -18,6 +18,9 @@
- Issue #23112: Fix SimpleHTTPServer to correctly carry the query string and
fragment when it redirects to add a trailing slash.
+- Issue #22585: On OpenBSD 5.6 and newer, os.urandom() now calls getentropy(),
+ instead of reading /dev/urandom, to get pseudo-random bytes.
+
- Issue #23093: In the io, module allow more operations to work on detached
streams.
diff --git a/Python/random.c b/Python/random.c
index 1e5776d..d10dda9 100644
--- a/Python/random.c
+++ b/Python/random.c
@@ -92,8 +92,33 @@
}
return 0;
}
-#endif /* MS_WINDOWS */
+#elif HAVE_GETENTROPY
+/* Fill buffer with size pseudo-random bytes generated by getentropy().
+ Return 0 on success, or raise an exception and return -1 on error.
+ If fatal is nonzero, call Py_FatalError() instead of raising an exception
+ on error. */
+static int
+py_getentropy(unsigned char *buffer, Py_ssize_t size, int fatal)
+{
+ while (size > 0) {
+ Py_ssize_t len = Py_MIN(size, 256);
+ int res = getentropy(buffer, len);
+ if (res < 0) {
+ if (fatal) {
+ Py_FatalError("getentropy() failed");
+ }
+ else {
+ PyErr_SetFromErrno(PyExc_OSError);
+ return -1;
+ }
+ }
+ buffer += len;
+ size -= len;
+ }
+ return 0;
+}
+#endif
#ifdef __VMS
/* Use openssl random routine */
@@ -291,6 +316,8 @@
#ifdef MS_WINDOWS
return win32_urandom((unsigned char *)buffer, size, 1);
+#elif HAVE_GETENTROPY
+ return py_getentropy(buffer, size, 0);
#else
# ifdef __VMS
return vms_urandom((unsigned char *)buffer, size, 1);
@@ -350,12 +377,12 @@
else {
#ifdef MS_WINDOWS
(void)win32_urandom((unsigned char *)secret, secret_size, 0);
-#else /* #ifdef MS_WINDOWS */
-# ifdef __VMS
+#elif __VMS
vms_urandom((unsigned char *)secret, secret_size, 0);
-# else
- dev_urandom_noraise((unsigned char*)secret, secret_size);
-# endif
+#elif HAVE_GETENTROPY
+ (void)py_getentropy(secret, secret_size, 1);
+#else
+ dev_urandom_noraise(secret, secret_size);
#endif
}
}
@@ -368,6 +395,8 @@
CryptReleaseContext(hCryptProv, 0);
hCryptProv = 0;
}
+#elif HAVE_GETENTROPY
+ /* nothing to clean */
#else
dev_urandom_close();
#endif
diff --git a/configure b/configure
index 09e65eb..133c88b 100755
--- a/configure
+++ b/configure
@@ -10196,7 +10196,8 @@
# checks for library functions
for ac_func in alarm setitimer getitimer bind_textdomain_codeset chown \
clock confstr ctermid execv fchmod fchown fork fpathconf ftime ftruncate \
- gai_strerror getgroups getlogin getloadavg getpeername getpgid getpid \
+ gai_strerror getentropy getgroups getlogin getloadavg getpeername getpgid \
+ getpid \
getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \
initgroups kill killpg lchmod lchown lstat mkfifo mknod mktime mmap \
mremap nice pathconf pause plock poll pthread_init \
diff --git a/configure.ac b/configure.ac
index e63edf5..75486f4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2913,6 +2913,7 @@
AC_CHECK_FUNCS(alarm setitimer getitimer bind_textdomain_codeset chown \
clock confstr ctermid execv fchmod fchown fork fpathconf ftime ftruncate \
gai_strerror getgroups getlogin getloadavg getpeername getpgid getpid \
+ getentropy \
getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \
initgroups kill killpg lchmod lchown lstat mkfifo mknod mktime mmap \
mremap nice pathconf pause plock poll pthread_init \
diff --git a/pyconfig.h.in b/pyconfig.h.in
index d6d479a..cb962a4 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -280,6 +280,9 @@
/* Define this if you have flockfile(), getc_unlocked(), and funlockfile() */
#undef HAVE_GETC_UNLOCKED
+/* Define to 1 if you have the `getentropy' function. */
+#undef HAVE_GETENTROPY
+
/* Define to 1 if you have the `getgroups' function. */
#undef HAVE_GETGROUPS