diff options
Diffstat (limited to 'gnu/packages/patches/python-3.5-getentropy-on-old-kernels.patch')
| -rw-r--r-- | gnu/packages/patches/python-3.5-getentropy-on-old-kernels.patch | 720 |
1 files changed, 720 insertions, 0 deletions
diff --git a/gnu/packages/patches/python-3.5-getentropy-on-old-kernels.patch b/gnu/packages/patches/python-3.5-getentropy-on-old-kernels.patch new file mode 100644 index 0000000000..8a12b5b448 --- /dev/null +++ b/gnu/packages/patches/python-3.5-getentropy-on-old-kernels.patch @@ -0,0 +1,720 @@ +This patch resolves a compatibility issue when compiled against glibc 2.25 +and run runder kernels < 3.17: + +https://bugzilla.redhat.com/show_bug.cgi?id=1410175 + +Upstream bug URL: https://bugs.python.org/issue29157 + +Patch copied from upstream source repository: + +https://hg.python.org/cpython/rev/8125d9a8152b + +# HG changeset patch +# User Victor Stinner <victor.stinner@gmail.com> +# Date 1483957133 -3600 +# Node ID 8125d9a8152b79e712cb09c7094b9129b9bcea86 +# Parent 337461574c90281630751b6095c4e1baf380cf7d +Issue #29157: Prefer getrandom() over getentropy() + +Copy and then adapt Python/random.c from default branch. Difference between 3.5 +and default branches: + +* Python 3.5 only uses getrandom() in non-blocking mode: flags=GRND_NONBLOCK +* If getrandom() fails with EAGAIN: py_getrandom() immediately fails and + remembers that getrandom() doesn't work. +* Python 3.5 has no _PyOS_URandomNonblock() function: _PyOS_URandom() + works in non-blocking mode on Python 3.5 + +diff --git a/Python/random.c b/Python/random.c +--- Python/random.c ++++ Python/random.c +@@ -1,6 +1,9 @@ + #include "Python.h" + #ifdef MS_WINDOWS + # include <windows.h> ++/* All sample MSDN wincrypt programs include the header below. It is at least ++ * required with Min GW. */ ++# include <wincrypt.h> + #else + # include <fcntl.h> + # ifdef HAVE_SYS_STAT_H +@@ -37,10 +40,9 @@ win32_urandom_init(int raise) + return 0; + + error: +- if (raise) ++ if (raise) { + PyErr_SetFromWindowsErr(0); +- else +- Py_FatalError("Failed to initialize Windows random API (CryptoGen)"); ++ } + return -1; + } + +@@ -53,8 +55,9 @@ win32_urandom(unsigned char *buffer, Py_ + + if (hCryptProv == 0) + { +- if (win32_urandom_init(raise) == -1) ++ if (win32_urandom_init(raise) == -1) { + return -1; ++ } + } + + while (size > 0) +@@ -63,11 +66,9 @@ win32_urandom(unsigned char *buffer, Py_ + if (!CryptGenRandom(hCryptProv, (DWORD)chunk, buffer)) + { + /* CryptGenRandom() failed */ +- if (raise) ++ if (raise) { + PyErr_SetFromWindowsErr(0); +- else +- Py_FatalError("Failed to initialized the randomized hash " +- "secret using CryptoGen)"); ++ } + return -1; + } + buffer += chunk; +@@ -76,58 +77,23 @@ win32_urandom(unsigned char *buffer, Py_ + return 0; + } + +-/* Issue #25003: Don't use getentropy() on Solaris (available since +- * Solaris 11.3), it is blocking whereas os.urandom() should not block. */ +-#elif defined(HAVE_GETENTROPY) && !defined(sun) +-#define PY_GETENTROPY 1 +- +-/* 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; +- +- if (!fatal) { +- Py_BEGIN_ALLOW_THREADS +- res = getentropy(buffer, len); +- Py_END_ALLOW_THREADS +- +- if (res < 0) { +- PyErr_SetFromErrno(PyExc_OSError); +- return -1; +- } +- } +- else { +- res = getentropy(buffer, len); +- if (res < 0) +- Py_FatalError("getentropy() failed"); +- } +- +- buffer += len; +- size -= len; +- } +- return 0; +-} +- +-#else ++#else /* !MS_WINDOWS */ + + #if defined(HAVE_GETRANDOM) || defined(HAVE_GETRANDOM_SYSCALL) + #define PY_GETRANDOM 1 + +-/* Call getrandom() ++/* Call getrandom() to get random bytes: ++ + - Return 1 on success +- - Return 0 if getrandom() syscall is not available (failed with ENOSYS or +- EPERM) or if getrandom(GRND_NONBLOCK) failed with EAGAIN (system urandom +- not initialized yet) and raise=0. ++ - Return 0 if getrandom() is not available (failed with ENOSYS or EPERM), ++ or if getrandom(GRND_NONBLOCK) failed with EAGAIN (system urandom not ++ initialized yet). + - Raise an exception (if raise is non-zero) and return -1 on error: +- getrandom() failed with EINTR and the Python signal handler raised an +- exception, or getrandom() failed with a different error. */ ++ if getrandom() failed with EINTR, raise is non-zero and the Python signal ++ handler raised an exception, or if getrandom() failed with a different ++ error. ++ ++ getrandom() is retried if it failed with EINTR: interrupted by a signal. */ + static int + py_getrandom(void *buffer, Py_ssize_t size, int raise) + { +@@ -142,16 +108,19 @@ py_getrandom(void *buffer, Py_ssize_t si + * see https://bugs.python.org/issue26839. To avoid this, use the + * GRND_NONBLOCK flag. */ + const int flags = GRND_NONBLOCK; ++ char *dest; + long n; + + if (!getrandom_works) { + return 0; + } + ++ dest = buffer; + while (0 < size) { + #ifdef sun + /* Issue #26735: On Solaris, getrandom() is limited to returning up +- to 1024 bytes */ ++ to 1024 bytes. Call it multiple times if more bytes are ++ requested. */ + n = Py_MIN(size, 1024); + #else + n = Py_MIN(size, LONG_MAX); +@@ -161,34 +130,35 @@ py_getrandom(void *buffer, Py_ssize_t si + #ifdef HAVE_GETRANDOM + if (raise) { + Py_BEGIN_ALLOW_THREADS +- n = getrandom(buffer, n, flags); ++ n = getrandom(dest, n, flags); + Py_END_ALLOW_THREADS + } + else { +- n = getrandom(buffer, n, flags); ++ n = getrandom(dest, n, 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 */ ++ expose the Linux getrandom() syscall yet. See: ++ https://sourceware.org/bugzilla/show_bug.cgi?id=17252 */ + if (raise) { + Py_BEGIN_ALLOW_THREADS +- n = syscall(SYS_getrandom, buffer, n, flags); ++ n = syscall(SYS_getrandom, dest, n, flags); + Py_END_ALLOW_THREADS + } + else { +- n = syscall(SYS_getrandom, buffer, n, flags); ++ n = syscall(SYS_getrandom, dest, n, flags); + } + #endif + + if (n < 0) { +- /* ENOSYS: getrandom() syscall not supported by the kernel (but +- * maybe supported by the host which built Python). EPERM: +- * getrandom() syscall blocked by SECCOMP or something else. */ ++ /* ENOSYS: the syscall is not supported by the kernel. ++ EPERM: the syscall is blocked by a security policy (ex: SECCOMP) ++ or something else. */ + if (errno == ENOSYS || errno == EPERM) { + getrandom_works = 0; + return 0; + } ++ + if (errno == EAGAIN) { + /* getrandom(GRND_NONBLOCK) fails with EAGAIN if the system + urandom is not initialiazed yet. In this case, fall back on +@@ -202,32 +172,101 @@ py_getrandom(void *buffer, Py_ssize_t si + } + + if (errno == EINTR) { +- if (PyErr_CheckSignals()) { +- if (!raise) { +- Py_FatalError("getrandom() interrupted by a signal"); ++ if (raise) { ++ if (PyErr_CheckSignals()) { ++ return -1; + } +- return -1; + } + +- /* retry getrandom() */ ++ /* retry getrandom() if it was interrupted by a signal */ + continue; + } + + if (raise) { + PyErr_SetFromErrno(PyExc_OSError); + } +- else { +- Py_FatalError("getrandom() failed"); ++ return -1; ++ } ++ ++ dest += n; ++ size -= n; ++ } ++ return 1; ++} ++ ++#elif defined(HAVE_GETENTROPY) ++#define PY_GETENTROPY 1 ++ ++/* Fill buffer with size pseudo-random bytes generated by getentropy(): ++ ++ - Return 1 on success ++ - Return 0 if getentropy() syscall is not available (failed with ENOSYS or ++ EPERM). ++ - Raise an exception (if raise is non-zero) and return -1 on error: ++ if getentropy() failed with EINTR, raise is non-zero and the Python signal ++ handler raised an exception, or if getentropy() failed with a different ++ error. ++ ++ getentropy() is retried if it failed with EINTR: interrupted by a signal. */ ++static int ++py_getentropy(char *buffer, Py_ssize_t size, int raise) ++{ ++ /* Is getentropy() supported by the running kernel? Set to 0 if ++ getentropy() failed with ENOSYS or EPERM. */ ++ static int getentropy_works = 1; ++ ++ if (!getentropy_works) { ++ return 0; ++ } ++ ++ while (size > 0) { ++ /* getentropy() is limited to returning up to 256 bytes. Call it ++ multiple times if more bytes are requested. */ ++ Py_ssize_t len = Py_MIN(size, 256); ++ int res; ++ ++ if (raise) { ++ Py_BEGIN_ALLOW_THREADS ++ res = getentropy(buffer, len); ++ Py_END_ALLOW_THREADS ++ } ++ else { ++ res = getentropy(buffer, len); ++ } ++ ++ if (res < 0) { ++ /* ENOSYS: the syscall is not supported by the running kernel. ++ EPERM: the syscall is blocked by a security policy (ex: SECCOMP) ++ or something else. */ ++ if (errno == ENOSYS || errno == EPERM) { ++ getentropy_works = 0; ++ return 0; ++ } ++ ++ if (errno == EINTR) { ++ if (raise) { ++ if (PyErr_CheckSignals()) { ++ return -1; ++ } ++ } ++ ++ /* retry getentropy() if it was interrupted by a signal */ ++ continue; ++ } ++ ++ if (raise) { ++ PyErr_SetFromErrno(PyExc_OSError); + } + return -1; + } + +- buffer += n; +- size -= n; ++ buffer += len; ++ size -= len; + } + return 1; + } +-#endif ++#endif /* defined(HAVE_GETENTROPY) && !defined(sun) */ ++ + + static struct { + int fd; +@@ -235,136 +274,123 @@ static struct { + ino_t st_ino; + } urandom_cache = { -1 }; + ++/* Read random bytes from the /dev/urandom device: + +-/* Read 'size' random bytes from py_getrandom(). Fall back on reading from +- /dev/urandom if getrandom() is not available. ++ - Return 0 on success ++ - Raise an exception (if raise is non-zero) and return -1 on error + +- Call Py_FatalError() on error. */ +-static void +-dev_urandom_noraise(unsigned char *buffer, Py_ssize_t size) ++ Possible causes of errors: ++ ++ - open() failed with ENOENT, ENXIO, ENODEV, EACCES: the /dev/urandom device ++ was not found. For example, it was removed manually or not exposed in a ++ chroot or container. ++ - open() failed with a different error ++ - fstat() failed ++ - read() failed or returned 0 ++ ++ read() is retried if it failed with EINTR: interrupted by a signal. ++ ++ The file descriptor of the device is kept open between calls to avoid using ++ many file descriptors when run in parallel from multiple threads: ++ see the issue #18756. ++ ++ st_dev and st_ino fields of the file descriptor (from fstat()) are cached to ++ check if the file descriptor was replaced by a different file (which is ++ likely a bug in the application): see the issue #21207. ++ ++ If the file descriptor was closed or replaced, open a new file descriptor ++ but don't close the old file descriptor: it probably points to something ++ important for some third-party code. */ ++static int ++dev_urandom(char *buffer, Py_ssize_t size, int raise) + { + int fd; + Py_ssize_t n; + +- assert (0 < size); ++ if (raise) { ++ struct _Py_stat_struct st; + +-#ifdef PY_GETRANDOM +- if (py_getrandom(buffer, size, 0) == 1) { +- return; ++ 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; ++ } ++ else { ++ 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); ++ return -1; ++ } ++ ++ buffer += n; ++ size -= n; ++ } while (0 < size); + } +- /* getrandom() failed with ENOSYS or EPERM, +- fall back on reading /dev/urandom */ +-#endif +- +- fd = _Py_open_noraise("/dev/urandom", O_RDONLY); +- if (fd < 0) { +- Py_FatalError("Failed to open /dev/urandom"); +- } +- +- while (0 < size) +- { +- do { +- n = read(fd, buffer, (size_t)size); +- } while (n < 0 && errno == EINTR); +- +- if (n <= 0) { +- /* read() failed or returned 0 bytes */ +- Py_FatalError("Failed to read bytes from /dev/urandom"); +- break; +- } +- buffer += n; +- size -= n; +- } +- close(fd); +-} +- +-/* Read 'size' random bytes from py_getrandom(). Fall back on reading from +- /dev/urandom if getrandom() is not available. +- +- Return 0 on success. Raise an exception and return -1 on error. */ +-static int +-dev_urandom_python(char *buffer, Py_ssize_t size) +-{ +- int fd; +- Py_ssize_t n; +- struct _Py_stat_struct st; +-#ifdef PY_GETRANDOM +- int res; +-#endif +- +- if (size <= 0) +- return 0; +- +-#ifdef PY_GETRANDOM +- res = py_getrandom(buffer, size, 1); +- if (res < 0) { +- return -1; +- } +- if (res == 1) { +- return 0; +- } +- /* getrandom() failed with ENOSYS or EPERM, +- fall back on reading /dev/urandom */ +-#endif +- +- 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); ++ fd = _Py_open_noraise("/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 { +- if (_Py_fstat(fd, &st)) { ++ ++ 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; + } +- else { +- urandom_cache.fd = fd; +- urandom_cache.st_dev = st.st_dev; +- urandom_cache.st_ino = st.st_ino; +- } ++ ++ buffer += n; ++ size -= n; + } ++ close(fd); + } +- +- 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); +- + 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): +@@ -400,29 +426,98 @@ lcg_urandom(unsigned int x0, unsigned ch + } + } + ++/* Read random bytes: ++ ++ - 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) { ++ if (raise) { ++ PyErr_Format(PyExc_ValueError, ++ "negative argument not allowed"); ++ } ++ return -1; ++ } ++ ++ if (size == 0) { ++ return 0; ++ } ++ ++#ifdef MS_WINDOWS ++ 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 ++ 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. */ ++ Return 0 on success. Raise an exception and return -1 on error. */ + int + _PyOS_URandom(void *buffer, Py_ssize_t size) + { +- if (size < 0) { +- PyErr_Format(PyExc_ValueError, +- "negative argument not allowed"); +- return -1; +- } +- 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); +-#else +- return dev_urandom_python((char*)buffer, size); +-#endif ++ return pyurandom(buffer, size, 1); + } + + void +@@ -463,13 +558,14 @@ 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 @@ void + CryptReleaseContext(hCryptProv, 0); + hCryptProv = 0; + } +-#elif defined(PY_GETENTROPY) +- /* nothing to clean */ + #else + dev_urandom_close(); + #endif + |