changeset: 98054:8b0c2c7cb4a7 user: Victor Stinner date: Fri Sep 18 15:38:37 2015 +0200 files: Misc/NEWS Python/random.c configure configure.ac pyconfig.h.in description: Issue #25003: On Solaris 11.3 or newer, os.urandom() now uses the getrandom() function instead of the getentropy() function. The getentropy() function is blocking to generate very good quality entropy, os.urandom() doesn't need such high-quality entropy. diff -r 8d3ae2fafab1 -r 8b0c2c7cb4a7 Misc/NEWS --- a/Misc/NEWS Fri Sep 18 15:08:14 2015 +0200 +++ b/Misc/NEWS Fri Sep 18 15:38:37 2015 +0200 @@ -10,6 +10,11 @@ Core and Builtins ----------------- +- Issue #25003: On Solaris 11.3 or newer, os.urandom() now uses the + getrandom() function instead of the getentropy() function. The getentropy() + function is blocking to generate very good quality entropy, os.urandom() + doesn't need such high-quality entropy. + - Issue #9232: Modify Python's grammar to allow trailing commas in the argument list of a function declaration. For example, "def f(*, a = 3,): pass" is now legal. Patch from Mark Dickinson. diff -r 8d3ae2fafab1 -r 8b0c2c7cb4a7 Python/random.c --- a/Python/random.c Fri Sep 18 15:08:14 2015 +0200 +++ b/Python/random.c Fri Sep 18 15:38:37 2015 +0200 @@ -6,7 +6,9 @@ # ifdef HAVE_SYS_STAT_H # include # endif -# ifdef HAVE_GETRANDOM_SYSCALL +# ifdef HAVE_GETRANDOM +# include +# elif defined(HAVE_GETRANDOM_SYSCALL) # include # endif #endif @@ -70,7 +72,9 @@ 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 @@ return 0; } -#else /* !HAVE_GETENTROPY */ +#else -#ifdef HAVE_GETRANDOM_SYSCALL +#if defined(HAVE_GETRANDOM) || defined(HAVE_GETRANDOM_SYSCALL) +#define PY_GETRANDOM + 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 @@ 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 @@ else { n = syscall(SYS_getrandom, buffer, size, flags); } +#endif if (n < 0) { if (errno == ENOSYS) { @@ -182,7 +201,7 @@ 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 @@ 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 @@ } } -#endif /* HAVE_GETENTROPY */ +#endif /* Fill buffer with pseudo-random bytes generated by a linear congruent generator (LCG): @@ -345,7 +364,7 @@ #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 @@ 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 @@ CryptReleaseContext(hCryptProv, 0); hCryptProv = 0; } -#elif HAVE_GETENTROPY +#elif PY_GETENTROPY /* nothing to clean */ #else dev_urandom_close(); diff -r 8d3ae2fafab1 -r 8b0c2c7cb4a7 configure --- a/configure Fri Sep 18 15:08:14 2015 +0200 +++ b/configure Fri Sep 18 15:38:37 2015 +0200 @@ -16005,11 +16005,11 @@ #include int main() { + char buffer[1]; + const size_t buflen = sizeof(buffer); const int flags = 0; - char buffer[1]; - int n; /* ignore the result, Python checks for ENOSYS at runtime */ - (void)syscall(SYS_getrandom, buffer, sizeof(buffer), flags); + (void)syscall(SYS_getrandom, buffer, buflen, flags); return 0; } @@ -16031,6 +16031,43 @@ fi +# check if the getrandom() function is available +# the test was written for the Solaris function of +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for the getrandom() function" >&5 +$as_echo_n "checking for the getrandom() function... " >&6; } +cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + + + #include + + int main() { + char buffer[1]; + const size_t buflen = sizeof(buffer); + const int flags = 0; + /* ignore the result, Python checks for ENOSYS at runtime */ + (void)getrandom(buffer, buflen, flags); + return 0; + } + + +_ACEOF +if ac_fn_c_try_link "$LINENO"; then : + have_getrandom=yes +else + have_getrandom=no +fi +rm -f core conftest.err conftest.$ac_objext \ + conftest$ac_exeext conftest.$ac_ext +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $have_getrandom" >&5 +$as_echo "$have_getrandom" >&6; } + +if test "$have_getrandom" = yes; then + +$as_echo "#define HAVE_GETRANDOM 1" >>confdefs.h + +fi + # generate output files ac_config_files="$ac_config_files Makefile.pre Modules/Setup.config Misc/python.pc Misc/python-config.sh" diff -r 8d3ae2fafab1 -r 8b0c2c7cb4a7 configure.ac --- a/configure.ac Fri Sep 18 15:08:14 2015 +0200 +++ b/configure.ac Fri Sep 18 15:38:37 2015 +0200 @@ -5111,11 +5111,11 @@ #include int main() { + char buffer[1]; + const size_t buflen = sizeof(buffer); const int flags = 0; - char buffer[1]; - int n; /* ignore the result, Python checks for ENOSYS at runtime */ - (void)syscall(SYS_getrandom, buffer, sizeof(buffer), flags); + (void)syscall(SYS_getrandom, buffer, buflen, flags); return 0; } ]]) @@ -5127,6 +5127,31 @@ [Define to 1 if the Linux getrandom() syscall is available]) fi +# check if the getrandom() function is available +# the test was written for the Solaris function of +AC_MSG_CHECKING(for the getrandom() function) +AC_LINK_IFELSE( +[ + AC_LANG_SOURCE([[ + #include + + int main() { + char buffer[1]; + const size_t buflen = sizeof(buffer); + const int flags = 0; + /* ignore the result, Python checks for ENOSYS at runtime */ + (void)getrandom(buffer, buflen, flags); + return 0; + } + ]]) +],[have_getrandom=yes],[have_getrandom=no]) +AC_MSG_RESULT($have_getrandom) + +if test "$have_getrandom" = yes; then + AC_DEFINE(HAVE_GETRANDOM, 1, + [Define to 1 if the getrandom() function is available]) +fi + # generate output files AC_CONFIG_FILES(Makefile.pre Modules/Setup.config Misc/python.pc Misc/python-config.sh) AC_CONFIG_FILES([Modules/ld_so_aix], [chmod +x Modules/ld_so_aix]) diff -r 8d3ae2fafab1 -r 8b0c2c7cb4a7 pyconfig.h.in --- a/pyconfig.h.in Fri Sep 18 15:08:14 2015 +0200 +++ b/pyconfig.h.in Fri Sep 18 15:38:37 2015 +0200 @@ -395,6 +395,9 @@ /* Define to 1 if you have the `getpwent' function. */ #undef HAVE_GETPWENT +/* Define to 1 if the getrandom() function is available */ +#undef HAVE_GETRANDOM + /* Define to 1 if the Linux getrandom() syscall is available */ #undef HAVE_GETRANDOM_SYSCALL