From fe02e3902920181b76e7e7a9c761209b7ddb1be1 Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Sun, 21 Dec 2014 01:16:38 +0100 Subject: [PATCH] Issue #22585: On OpenBSD 5.6 and newer, os.urandom() now calls getentropy(), instead of reading /dev/urandom, to get pseudo-random bytes. --- Lib/test/test_os.py | 7 +++++++ Misc/NEWS | 3 +++ Python/random.c | 48 ++++++++++++++++++++++++++++++++++++++------- configure | 2 +- configure.ac | 2 +- pyconfig.h.in | 3 +++ 6 files changed, 56 insertions(+), 9 deletions(-) diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py index ce6bd91cc72..152ba935762 100644 --- a/Lib/test/test_os.py +++ b/Lib/test/test_os.py @@ -27,6 +27,7 @@ import codecs import decimal import fractions import pickle +import sysconfig try: import threading except ImportError: @@ -1053,6 +1054,12 @@ class URandomTests(unittest.TestCase): 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 82cdbfd5a72..7932c77f1cc 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -41,6 +41,9 @@ Core and Builtins Library ------- +- Issue #22585: On OpenBSD 5.6 and newer, os.urandom() now calls getentropy(), + instead of reading /dev/urandom, to get pseudo-random bytes. + - Issue #23112: Fix SimpleHTTPServer to correctly carry the query string and fragment when it redirects to add a trailing slash. diff --git a/Python/random.c b/Python/random.c index 08030067bf6..93d300dae45 100644 --- a/Python/random.c +++ b/Python/random.c @@ -15,8 +15,6 @@ static int _Py_HashSecret_Initialized = 0; #endif #ifdef MS_WINDOWS -/* This handle is never explicitly released. Instead, the operating - system will release it when the process terminates. */ static HCRYPTPROV hCryptProv = 0; static int @@ -38,7 +36,7 @@ error: } /* Fill buffer with size pseudo-random bytes generated by the Windows CryptoGen - API. Return 0 on success, or -1 on error. */ + API. Return 0 on success, or raise an exception and return -1 on error. */ static int win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise) { @@ -68,10 +66,35 @@ win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise) } 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. -#ifndef MS_WINDOWS + 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; +} + +#else static struct { int fd; dev_t st_dev; @@ -203,7 +226,7 @@ dev_urandom_close(void) } } -#endif /* MS_WINDOWS */ +#endif /* HAVE_GETENTROPY */ /* Fill buffer with pseudo-random bytes generated by a linear congruent generator (LCG): @@ -244,6 +267,8 @@ _PyOS_URandom(void *buffer, Py_ssize_t size) #ifdef MS_WINDOWS return win32_urandom((unsigned char *)buffer, size, 1); +#elif HAVE_GETENTROPY + return py_getentropy(buffer, size, 0); #else return dev_urandom_python((char*)buffer, size); #endif @@ -289,6 +314,8 @@ _PyRandom_Init(void) else { #ifdef MS_WINDOWS (void)win32_urandom(secret, secret_size, 0); +#elif HAVE_GETENTROPY + (void)py_getentropy(secret, secret_size, 1); #else dev_urandom_noraise(secret, secret_size); #endif @@ -298,7 +325,14 @@ _PyRandom_Init(void) void _PyRandom_Fini(void) { -#ifndef MS_WINDOWS +#ifdef MS_WINDOWS + if (hCryptProv) { + CryptReleaseContext(hCryptProv, 0); + hCryptProv = 0; + } +#elif HAVE_GETENTROPY + /* nothing to clean */ +#else dev_urandom_close(); #endif } diff --git a/configure b/configure index 21bab5ba577..79e937695fb 100755 --- a/configure +++ b/configure @@ -10495,7 +10495,7 @@ fi for ac_func in alarm accept4 setitimer getitimer bind_textdomain_codeset chown \ clock confstr ctermid dup3 execv faccessat fchmod fchmodat fchown fchownat \ fexecve fdopendir fork fpathconf fstatat ftime ftruncate futimesat \ - futimens futimes gai_strerror \ + futimens futimes gai_strerror getentropy \ getgrouplist getgroups getlogin getloadavg getpeername getpgid getpid \ getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \ if_nameindex \ diff --git a/configure.ac b/configure.ac index 8177e272c07..21f4152b4b7 100644 --- a/configure.ac +++ b/configure.ac @@ -2935,7 +2935,7 @@ fi AC_CHECK_FUNCS(alarm accept4 setitimer getitimer bind_textdomain_codeset chown \ clock confstr ctermid dup3 execv faccessat fchmod fchmodat fchown fchownat \ fexecve fdopendir fork fpathconf fstatat ftime ftruncate futimesat \ - futimens futimes gai_strerror \ + futimens futimes gai_strerror getentropy \ getgrouplist getgroups getlogin getloadavg getpeername getpgid getpid \ getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \ if_nameindex \ diff --git a/pyconfig.h.in b/pyconfig.h.in index 3574f67322d..b3a3e176691 100644 --- a/pyconfig.h.in +++ b/pyconfig.h.in @@ -329,6 +329,9 @@ /* 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 `getgrouplist' function. */ #undef HAVE_GETGROUPLIST