forked from brl/citadel
704 lines
23 KiB
Diff
704 lines
23 KiB
Diff
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From 035ba5da3e53e45c712b39fe1f6fb743e697c032 Mon Sep 17 00:00:00 2001
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From: Victor Stinner <victor.stinner@gmail.com>
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Date: Mon, 9 Jan 2017 11:18:53 +0100
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Subject: [PATCH] Issue #29157: Prefer getrandom() over getentropy()
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Copy and then adapt Python/random.c from default branch. Difference between 3.5
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and default branches:
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* Python 3.5 only uses getrandom() in non-blocking mode: flags=GRND_NONBLOCK
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* If getrandom() fails with EAGAIN: py_getrandom() immediately fails and
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remembers that getrandom() doesn't work.
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* Python 3.5 has no _PyOS_URandomNonblock() function: _PyOS_URandom()
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works in non-blocking mode on Python 3.5
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Upstream-Status: Backport [https://github.com/python/cpython/commit/035ba5da3e53e45c712b39fe1f6fb743e697c032]
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Signed-off-by: Alexander Kanavin <alexander.kanavin@intel.com>
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---
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Python/random.c | 494 +++++++++++++++++++++++++++++++++-----------------------
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1 file changed, 294 insertions(+), 200 deletions(-)
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diff --git a/Python/random.c b/Python/random.c
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index d203939..31f61d0 100644
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--- a/Python/random.c
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+++ b/Python/random.c
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@@ -1,6 +1,9 @@
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#include "Python.h"
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#ifdef MS_WINDOWS
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# include <windows.h>
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+/* All sample MSDN wincrypt programs include the header below. It is at least
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+ * required with Min GW. */
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+# include <wincrypt.h>
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#else
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# include <fcntl.h>
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# ifdef HAVE_SYS_STAT_H
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@@ -37,10 +40,9 @@ win32_urandom_init(int raise)
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return 0;
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error:
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- if (raise)
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+ if (raise) {
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PyErr_SetFromWindowsErr(0);
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- else
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- Py_FatalError("Failed to initialize Windows random API (CryptoGen)");
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+ }
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return -1;
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}
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@@ -53,8 +55,9 @@ win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
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if (hCryptProv == 0)
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{
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- if (win32_urandom_init(raise) == -1)
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+ if (win32_urandom_init(raise) == -1) {
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return -1;
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+ }
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}
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while (size > 0)
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@@ -63,11 +66,9 @@ win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
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if (!CryptGenRandom(hCryptProv, (DWORD)chunk, buffer))
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{
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/* CryptGenRandom() failed */
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- if (raise)
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+ if (raise) {
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PyErr_SetFromWindowsErr(0);
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- else
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- Py_FatalError("Failed to initialized the randomized hash "
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- "secret using CryptoGen)");
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+ }
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return -1;
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}
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buffer += chunk;
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@@ -76,58 +77,23 @@ win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
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return 0;
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}
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-/* Issue #25003: Don't use getentropy() on Solaris (available since
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- * Solaris 11.3), it is blocking whereas os.urandom() should not block. */
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-#elif defined(HAVE_GETENTROPY) && !defined(sun)
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-#define PY_GETENTROPY 1
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-
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-/* Fill buffer with size pseudo-random bytes generated by getentropy().
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- Return 0 on success, or raise an exception and return -1 on error.
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-
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- If fatal is nonzero, call Py_FatalError() instead of raising an exception
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- on error. */
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-static int
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-py_getentropy(unsigned char *buffer, Py_ssize_t size, int fatal)
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-{
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- while (size > 0) {
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- Py_ssize_t len = Py_MIN(size, 256);
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- int res;
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-
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- if (!fatal) {
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- Py_BEGIN_ALLOW_THREADS
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- res = getentropy(buffer, len);
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- Py_END_ALLOW_THREADS
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-
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- if (res < 0) {
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- PyErr_SetFromErrno(PyExc_OSError);
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- return -1;
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- }
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- }
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- else {
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- res = getentropy(buffer, len);
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- if (res < 0)
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- Py_FatalError("getentropy() failed");
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- }
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-
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- buffer += len;
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- size -= len;
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- }
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- return 0;
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-}
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-
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-#else
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+#else /* !MS_WINDOWS */
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#if defined(HAVE_GETRANDOM) || defined(HAVE_GETRANDOM_SYSCALL)
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#define PY_GETRANDOM 1
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-/* Call getrandom()
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+/* Call getrandom() to get random bytes:
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+
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- Return 1 on success
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- - Return 0 if getrandom() syscall is not available (failed with ENOSYS or
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- EPERM) or if getrandom(GRND_NONBLOCK) failed with EAGAIN (system urandom
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- not initialized yet) and raise=0.
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+ - Return 0 if getrandom() is not available (failed with ENOSYS or EPERM),
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+ or if getrandom(GRND_NONBLOCK) failed with EAGAIN (system urandom not
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+ initialized yet).
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- Raise an exception (if raise is non-zero) and return -1 on error:
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- getrandom() failed with EINTR and the Python signal handler raised an
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- exception, or getrandom() failed with a different error. */
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+ if getrandom() failed with EINTR, raise is non-zero and the Python signal
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+ handler raised an exception, or if getrandom() failed with a different
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+ error.
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+
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+ getrandom() is retried if it failed with EINTR: interrupted by a signal. */
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static int
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py_getrandom(void *buffer, Py_ssize_t size, int raise)
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{
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@@ -142,16 +108,19 @@ py_getrandom(void *buffer, Py_ssize_t size, int raise)
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* see https://bugs.python.org/issue26839. To avoid this, use the
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* GRND_NONBLOCK flag. */
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const int flags = GRND_NONBLOCK;
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+ char *dest;
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long n;
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if (!getrandom_works) {
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return 0;
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}
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+ dest = buffer;
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while (0 < size) {
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#ifdef sun
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/* Issue #26735: On Solaris, getrandom() is limited to returning up
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- to 1024 bytes */
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+ to 1024 bytes. Call it multiple times if more bytes are
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+ requested. */
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n = Py_MIN(size, 1024);
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#else
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n = Py_MIN(size, LONG_MAX);
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@@ -161,34 +130,35 @@ py_getrandom(void *buffer, Py_ssize_t size, int raise)
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#ifdef HAVE_GETRANDOM
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if (raise) {
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Py_BEGIN_ALLOW_THREADS
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- n = getrandom(buffer, n, flags);
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+ n = getrandom(dest, n, flags);
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Py_END_ALLOW_THREADS
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}
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else {
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- n = getrandom(buffer, n, flags);
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+ n = getrandom(dest, n, flags);
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}
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#else
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/* On Linux, use the syscall() function because the GNU libc doesn't
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- * expose the Linux getrandom() syscall yet. See:
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- * https://sourceware.org/bugzilla/show_bug.cgi?id=17252 */
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+ expose the Linux getrandom() syscall yet. See:
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+ https://sourceware.org/bugzilla/show_bug.cgi?id=17252 */
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if (raise) {
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Py_BEGIN_ALLOW_THREADS
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- n = syscall(SYS_getrandom, buffer, n, flags);
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+ n = syscall(SYS_getrandom, dest, n, flags);
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Py_END_ALLOW_THREADS
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}
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else {
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- n = syscall(SYS_getrandom, buffer, n, flags);
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+ n = syscall(SYS_getrandom, dest, n, flags);
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}
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#endif
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if (n < 0) {
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- /* ENOSYS: getrandom() syscall not supported by the kernel (but
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- * maybe supported by the host which built Python). EPERM:
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- * getrandom() syscall blocked by SECCOMP or something else. */
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+ /* ENOSYS: the syscall is not supported by the kernel.
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+ EPERM: the syscall is blocked by a security policy (ex: SECCOMP)
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+ or something else. */
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if (errno == ENOSYS || errno == EPERM) {
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getrandom_works = 0;
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return 0;
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}
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+
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if (errno == EAGAIN) {
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/* getrandom(GRND_NONBLOCK) fails with EAGAIN if the system
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urandom is not initialiazed yet. In this case, fall back on
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@@ -202,169 +172,225 @@ py_getrandom(void *buffer, Py_ssize_t size, int raise)
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}
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if (errno == EINTR) {
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- if (PyErr_CheckSignals()) {
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- if (!raise) {
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- Py_FatalError("getrandom() interrupted by a signal");
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+ if (raise) {
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+ if (PyErr_CheckSignals()) {
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+ return -1;
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}
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- return -1;
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}
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- /* retry getrandom() */
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+ /* retry getrandom() if it was interrupted by a signal */
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continue;
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}
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if (raise) {
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PyErr_SetFromErrno(PyExc_OSError);
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}
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- else {
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- Py_FatalError("getrandom() failed");
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- }
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return -1;
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}
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- buffer += n;
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+ dest += n;
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size -= n;
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}
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return 1;
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}
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-#endif
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-static struct {
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- int fd;
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- dev_t st_dev;
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- ino_t st_ino;
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-} urandom_cache = { -1 };
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+#elif defined(HAVE_GETENTROPY)
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+#define PY_GETENTROPY 1
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+/* Fill buffer with size pseudo-random bytes generated by getentropy():
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-/* Read 'size' random bytes from py_getrandom(). Fall back on reading from
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- /dev/urandom if getrandom() is not available.
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+ - Return 1 on success
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+ - Return 0 if getentropy() syscall is not available (failed with ENOSYS or
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+ EPERM).
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+ - Raise an exception (if raise is non-zero) and return -1 on error:
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+ if getentropy() failed with EINTR, raise is non-zero and the Python signal
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+ handler raised an exception, or if getentropy() failed with a different
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+ error.
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- Call Py_FatalError() on error. */
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-static void
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-dev_urandom_noraise(unsigned char *buffer, Py_ssize_t size)
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+ getentropy() is retried if it failed with EINTR: interrupted by a signal. */
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+static int
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+py_getentropy(char *buffer, Py_ssize_t size, int raise)
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{
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- int fd;
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- Py_ssize_t n;
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+ /* Is getentropy() supported by the running kernel? Set to 0 if
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+ getentropy() failed with ENOSYS or EPERM. */
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+ static int getentropy_works = 1;
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- assert (0 < size);
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-
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-#ifdef PY_GETRANDOM
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- if (py_getrandom(buffer, size, 0) == 1) {
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- return;
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+ if (!getentropy_works) {
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+ return 0;
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}
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- /* getrandom() failed with ENOSYS or EPERM,
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- fall back on reading /dev/urandom */
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-#endif
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- fd = _Py_open_noraise("/dev/urandom", O_RDONLY);
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- if (fd < 0) {
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- Py_FatalError("Failed to open /dev/urandom");
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- }
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+ while (size > 0) {
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+ /* getentropy() is limited to returning up to 256 bytes. Call it
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+ multiple times if more bytes are requested. */
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+ Py_ssize_t len = Py_MIN(size, 256);
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+ int res;
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- while (0 < size)
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- {
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- do {
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- n = read(fd, buffer, (size_t)size);
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- } while (n < 0 && errno == EINTR);
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+ if (raise) {
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+ Py_BEGIN_ALLOW_THREADS
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+ res = getentropy(buffer, len);
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+ Py_END_ALLOW_THREADS
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+ }
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+ else {
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+ res = getentropy(buffer, len);
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+ }
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- if (n <= 0) {
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- /* read() failed or returned 0 bytes */
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- Py_FatalError("Failed to read bytes from /dev/urandom");
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- break;
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+ if (res < 0) {
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+ /* ENOSYS: the syscall is not supported by the running kernel.
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+ EPERM: the syscall is blocked by a security policy (ex: SECCOMP)
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+ or something else. */
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+ if (errno == ENOSYS || errno == EPERM) {
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+ getentropy_works = 0;
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+ return 0;
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+ }
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+
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+ if (errno == EINTR) {
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+ if (raise) {
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+ if (PyErr_CheckSignals()) {
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+ return -1;
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+ }
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+ }
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+
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+ /* retry getentropy() if it was interrupted by a signal */
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+ continue;
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+ }
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+
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+ if (raise) {
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+ PyErr_SetFromErrno(PyExc_OSError);
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+ }
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+ return -1;
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}
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- buffer += n;
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- size -= n;
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+
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+ buffer += len;
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+ size -= len;
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}
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- close(fd);
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+ return 1;
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}
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+#endif /* defined(HAVE_GETENTROPY) && !defined(sun) */
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-/* Read 'size' random bytes from py_getrandom(). Fall back on reading from
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- /dev/urandom if getrandom() is not available.
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- Return 0 on success. Raise an exception and return -1 on error. */
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+static struct {
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+ int fd;
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+ dev_t st_dev;
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+ ino_t st_ino;
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+} urandom_cache = { -1 };
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+
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+/* Read random bytes from the /dev/urandom device:
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+
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+ - Return 0 on success
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+ - Raise an exception (if raise is non-zero) and return -1 on error
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+
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+ Possible causes of errors:
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+
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+ - open() failed with ENOENT, ENXIO, ENODEV, EACCES: the /dev/urandom device
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+ was not found. For example, it was removed manually or not exposed in a
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+ chroot or container.
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+ - open() failed with a different error
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+ - fstat() failed
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+ - read() failed or returned 0
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+
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+ read() is retried if it failed with EINTR: interrupted by a signal.
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+
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+ The file descriptor of the device is kept open between calls to avoid using
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+ many file descriptors when run in parallel from multiple threads:
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+ see the issue #18756.
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+
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+ st_dev and st_ino fields of the file descriptor (from fstat()) are cached to
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+ check if the file descriptor was replaced by a different file (which is
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+ likely a bug in the application): see the issue #21207.
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+
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+ If the file descriptor was closed or replaced, open a new file descriptor
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+ but don't close the old file descriptor: it probably points to something
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+ important for some third-party code. */
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static int
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-dev_urandom_python(char *buffer, Py_ssize_t size)
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+dev_urandom(char *buffer, Py_ssize_t size, int raise)
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{
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int fd;
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Py_ssize_t n;
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- struct _Py_stat_struct st;
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-#ifdef PY_GETRANDOM
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- int res;
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-#endif
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-
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- if (size <= 0)
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- return 0;
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-#ifdef PY_GETRANDOM
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- res = py_getrandom(buffer, size, 1);
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- if (res < 0) {
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- return -1;
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- }
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- if (res == 1) {
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- return 0;
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- }
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- /* getrandom() failed with ENOSYS or EPERM,
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- fall back on reading /dev/urandom */
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-#endif
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+ if (raise) {
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+ struct _Py_stat_struct st;
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||
|
- if (urandom_cache.fd >= 0) {
|
||
|
- /* Does the fd point to the same thing as before? (issue #21207) */
|
||
|
- if (_Py_fstat_noraise(urandom_cache.fd, &st)
|
||
|
- || st.st_dev != urandom_cache.st_dev
|
||
|
- || st.st_ino != urandom_cache.st_ino) {
|
||
|
- /* Something changed: forget the cached fd (but don't close it,
|
||
|
- since it probably points to something important for some
|
||
|
- third-party code). */
|
||
|
- urandom_cache.fd = -1;
|
||
|
- }
|
||
|
- }
|
||
|
- if (urandom_cache.fd >= 0)
|
||
|
- fd = urandom_cache.fd;
|
||
|
- else {
|
||
|
- fd = _Py_open("/dev/urandom", O_RDONLY);
|
||
|
- if (fd < 0) {
|
||
|
- if (errno == ENOENT || errno == ENXIO ||
|
||
|
- errno == ENODEV || errno == EACCES)
|
||
|
- PyErr_SetString(PyExc_NotImplementedError,
|
||
|
- "/dev/urandom (or equivalent) not found");
|
||
|
- /* otherwise, keep the OSError exception raised by _Py_open() */
|
||
|
- return -1;
|
||
|
- }
|
||
|
if (urandom_cache.fd >= 0) {
|
||
|
- /* urandom_fd was initialized by another thread while we were
|
||
|
- not holding the GIL, keep it. */
|
||
|
- close(fd);
|
||
|
- fd = urandom_cache.fd;
|
||
|
+ /* Does the fd point to the same thing as before? (issue #21207) */
|
||
|
+ if (_Py_fstat_noraise(urandom_cache.fd, &st)
|
||
|
+ || st.st_dev != urandom_cache.st_dev
|
||
|
+ || st.st_ino != urandom_cache.st_ino) {
|
||
|
+ /* Something changed: forget the cached fd (but don't close it,
|
||
|
+ since it probably points to something important for some
|
||
|
+ third-party code). */
|
||
|
+ urandom_cache.fd = -1;
|
||
|
+ }
|
||
|
}
|
||
|
+ if (urandom_cache.fd >= 0)
|
||
|
+ fd = urandom_cache.fd;
|
||
|
else {
|
||
|
- if (_Py_fstat(fd, &st)) {
|
||
|
- close(fd);
|
||
|
+ fd = _Py_open("/dev/urandom", O_RDONLY);
|
||
|
+ if (fd < 0) {
|
||
|
+ if (errno == ENOENT || errno == ENXIO ||
|
||
|
+ errno == ENODEV || errno == EACCES) {
|
||
|
+ PyErr_SetString(PyExc_NotImplementedError,
|
||
|
+ "/dev/urandom (or equivalent) not found");
|
||
|
+ }
|
||
|
+ /* otherwise, keep the OSError exception raised by _Py_open() */
|
||
|
return -1;
|
||
|
}
|
||
|
+ if (urandom_cache.fd >= 0) {
|
||
|
+ /* urandom_fd was initialized by another thread while we were
|
||
|
+ not holding the GIL, keep it. */
|
||
|
+ close(fd);
|
||
|
+ fd = urandom_cache.fd;
|
||
|
+ }
|
||
|
else {
|
||
|
- urandom_cache.fd = fd;
|
||
|
- urandom_cache.st_dev = st.st_dev;
|
||
|
- urandom_cache.st_ino = st.st_ino;
|
||
|
+ if (_Py_fstat(fd, &st)) {
|
||
|
+ close(fd);
|
||
|
+ return -1;
|
||
|
+ }
|
||
|
+ else {
|
||
|
+ urandom_cache.fd = fd;
|
||
|
+ urandom_cache.st_dev = st.st_dev;
|
||
|
+ urandom_cache.st_ino = st.st_ino;
|
||
|
+ }
|
||
|
}
|
||
|
}
|
||
|
- }
|
||
|
|
||
|
- do {
|
||
|
- n = _Py_read(fd, buffer, (size_t)size);
|
||
|
- if (n == -1) {
|
||
|
- return -1;
|
||
|
- }
|
||
|
- if (n == 0) {
|
||
|
- PyErr_Format(PyExc_RuntimeError,
|
||
|
- "Failed to read %zi bytes from /dev/urandom",
|
||
|
- size);
|
||
|
+ do {
|
||
|
+ n = _Py_read(fd, buffer, (size_t)size);
|
||
|
+ if (n == -1)
|
||
|
+ return -1;
|
||
|
+ if (n == 0) {
|
||
|
+ PyErr_Format(PyExc_RuntimeError,
|
||
|
+ "Failed to read %zi bytes from /dev/urandom",
|
||
|
+ size);
|
||
|
+ return -1;
|
||
|
+ }
|
||
|
+
|
||
|
+ buffer += n;
|
||
|
+ size -= n;
|
||
|
+ } while (0 < size);
|
||
|
+ }
|
||
|
+ else {
|
||
|
+ fd = _Py_open_noraise("/dev/urandom", O_RDONLY);
|
||
|
+ if (fd < 0) {
|
||
|
return -1;
|
||
|
}
|
||
|
|
||
|
- buffer += n;
|
||
|
- size -= n;
|
||
|
- } while (0 < size);
|
||
|
+ while (0 < size)
|
||
|
+ {
|
||
|
+ do {
|
||
|
+ n = read(fd, buffer, (size_t)size);
|
||
|
+ } while (n < 0 && errno == EINTR);
|
||
|
|
||
|
+ if (n <= 0) {
|
||
|
+ /* stop on error or if read(size) returned 0 */
|
||
|
+ close(fd);
|
||
|
+ return -1;
|
||
|
+ }
|
||
|
+
|
||
|
+ buffer += n;
|
||
|
+ size -= n;
|
||
|
+ }
|
||
|
+ close(fd);
|
||
|
+ }
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
@@ -376,8 +402,8 @@ dev_urandom_close(void)
|
||
|
urandom_cache.fd = -1;
|
||
|
}
|
||
|
}
|
||
|
+#endif /* !MS_WINDOWS */
|
||
|
|
||
|
-#endif
|
||
|
|
||
|
/* Fill buffer with pseudo-random bytes generated by a linear congruent
|
||
|
generator (LCG):
|
||
|
@@ -400,31 +426,100 @@ lcg_urandom(unsigned int x0, unsigned char *buffer, size_t size)
|
||
|
}
|
||
|
}
|
||
|
|
||
|
-/* Fill buffer with size pseudo-random bytes from the operating system random
|
||
|
- number generator (RNG). It is suitable for most cryptographic purposes
|
||
|
- except long living private keys for asymmetric encryption.
|
||
|
+/* Read random bytes:
|
||
|
|
||
|
- Return 0 on success, raise an exception and return -1 on error. */
|
||
|
-int
|
||
|
-_PyOS_URandom(void *buffer, Py_ssize_t size)
|
||
|
+ - Return 0 on success
|
||
|
+ - Raise an exception (if raise is non-zero) and return -1 on error
|
||
|
+
|
||
|
+ Used sources of entropy ordered by preference, preferred source first:
|
||
|
+
|
||
|
+ - CryptGenRandom() on Windows
|
||
|
+ - getrandom() function (ex: Linux and Solaris): call py_getrandom()
|
||
|
+ - getentropy() function (ex: OpenBSD): call py_getentropy()
|
||
|
+ - /dev/urandom device
|
||
|
+
|
||
|
+ Read from the /dev/urandom device if getrandom() or getentropy() function
|
||
|
+ is not available or does not work.
|
||
|
+
|
||
|
+ Prefer getrandom() over getentropy() because getrandom() supports blocking
|
||
|
+ and non-blocking mode and Python requires non-blocking RNG at startup to
|
||
|
+ initialize its hash secret: see the PEP 524.
|
||
|
+
|
||
|
+ Prefer getrandom() and getentropy() over reading directly /dev/urandom
|
||
|
+ because these functions don't need file descriptors and so avoid ENFILE or
|
||
|
+ EMFILE errors (too many open files): see the issue #18756.
|
||
|
+
|
||
|
+ Only use RNG running in the kernel. They are more secure because it is
|
||
|
+ harder to get the internal state of a RNG running in the kernel land than a
|
||
|
+ RNG running in the user land. The kernel has a direct access to the hardware
|
||
|
+ and has access to hardware RNG, they are used as entropy sources.
|
||
|
+
|
||
|
+ Note: the OpenSSL RAND_pseudo_bytes() function does not automatically reseed
|
||
|
+ its RNG on fork(), two child processes (with the same pid) generate the same
|
||
|
+ random numbers: see issue #18747. Kernel RNGs don't have this issue,
|
||
|
+ they have access to good quality entropy sources.
|
||
|
+
|
||
|
+ If raise is zero:
|
||
|
+
|
||
|
+ - Don't raise an exception on error
|
||
|
+ - Don't call the Python signal handler (don't call PyErr_CheckSignals()) if
|
||
|
+ a function fails with EINTR: retry directly the interrupted function
|
||
|
+ - Don't release the GIL to call functions.
|
||
|
+*/
|
||
|
+static int
|
||
|
+pyurandom(void *buffer, Py_ssize_t size, int raise)
|
||
|
{
|
||
|
+#if defined(PY_GETRANDOM) || defined(PY_GETENTROPY)
|
||
|
+ int res;
|
||
|
+#endif
|
||
|
+
|
||
|
if (size < 0) {
|
||
|
- PyErr_Format(PyExc_ValueError,
|
||
|
- "negative argument not allowed");
|
||
|
+ if (raise) {
|
||
|
+ PyErr_Format(PyExc_ValueError,
|
||
|
+ "negative argument not allowed");
|
||
|
+ }
|
||
|
return -1;
|
||
|
}
|
||
|
- if (size == 0)
|
||
|
+
|
||
|
+ if (size == 0) {
|
||
|
return 0;
|
||
|
+ }
|
||
|
|
||
|
#ifdef MS_WINDOWS
|
||
|
- return win32_urandom((unsigned char *)buffer, size, 1);
|
||
|
-#elif defined(PY_GETENTROPY)
|
||
|
- return py_getentropy(buffer, size, 0);
|
||
|
+ return win32_urandom((unsigned char *)buffer, size, raise);
|
||
|
+#else
|
||
|
+
|
||
|
+#if defined(PY_GETRANDOM) || defined(PY_GETENTROPY)
|
||
|
+#ifdef PY_GETRANDOM
|
||
|
+ res = py_getrandom(buffer, size, raise);
|
||
|
#else
|
||
|
- return dev_urandom_python((char*)buffer, size);
|
||
|
+ res = py_getentropy(buffer, size, raise);
|
||
|
+#endif
|
||
|
+ if (res < 0) {
|
||
|
+ return -1;
|
||
|
+ }
|
||
|
+ if (res == 1) {
|
||
|
+ return 0;
|
||
|
+ }
|
||
|
+ /* getrandom() or getentropy() function is not available: failed with
|
||
|
+ ENOSYS, EPERM or EAGAIN. Fall back on reading from /dev/urandom. */
|
||
|
+#endif
|
||
|
+
|
||
|
+ return dev_urandom(buffer, size, raise);
|
||
|
#endif
|
||
|
}
|
||
|
|
||
|
+/* Fill buffer with size pseudo-random bytes from the operating system random
|
||
|
+ number generator (RNG). It is suitable for most cryptographic purposes
|
||
|
+ except long living private keys for asymmetric encryption.
|
||
|
+
|
||
|
+ Return 0 on success. Raise an exception and return -1 on error. */
|
||
|
+int
|
||
|
+_PyOS_URandom(void *buffer, Py_ssize_t size)
|
||
|
+{
|
||
|
+ return pyurandom(buffer, size, 1);
|
||
|
+}
|
||
|
+
|
||
|
void
|
||
|
_PyRandom_Init(void)
|
||
|
{
|
||
|
@@ -463,13 +558,14 @@ _PyRandom_Init(void)
|
||
|
}
|
||
|
}
|
||
|
else {
|
||
|
-#ifdef MS_WINDOWS
|
||
|
- (void)win32_urandom(secret, secret_size, 0);
|
||
|
-#elif defined(PY_GETENTROPY)
|
||
|
- (void)py_getentropy(secret, secret_size, 1);
|
||
|
-#else
|
||
|
- dev_urandom_noraise(secret, secret_size);
|
||
|
-#endif
|
||
|
+ int res;
|
||
|
+
|
||
|
+ /* _PyRandom_Init() is called very early in the Python initialization
|
||
|
+ and so exceptions cannot be used (use raise=0). */
|
||
|
+ res = pyurandom(secret, secret_size, 0);
|
||
|
+ if (res < 0) {
|
||
|
+ Py_FatalError("failed to get random numbers to initialize Python");
|
||
|
+ }
|
||
|
}
|
||
|
}
|
||
|
|
||
|
@@ -481,8 +577,6 @@ _PyRandom_Fini(void)
|
||
|
CryptReleaseContext(hCryptProv, 0);
|
||
|
hCryptProv = 0;
|
||
|
}
|
||
|
-#elif defined(PY_GETENTROPY)
|
||
|
- /* nothing to clean */
|
||
|
#else
|
||
|
dev_urandom_close();
|
||
|
#endif
|