main/python3: backport upstream fix for getrandom

upstream bug report: https://bugs.python.org/issue27955

2 files changed, 266 insertions, 4 deletions

diff --git a/main/python3/APKBUILD b/main/python3/APKBUILD
index d5b1c6c4f6..432a150a83 100644
--- a/main/python3/APKBUILD
+++ b/main/python3/APKBUILD
@@ -4,7 +4,7 @@
 pkgname=python3
 pkgver=3.5.2
 _basever="${pkgver%.*}"
-pkgrel=8
+pkgrel=9
 pkgdesc="A high-level scripting language"
 url="http://www.python.org"
 arch="all"
@@ -18,6 +18,7 @@ makedepends="expat-dev libressl-dev zlib-dev ncurses-dev bzip2-dev xz-dev
 	tk tk-dev"
 source="http://www.python.org/ftp/python/$pkgver/Python-$pkgver.tar.xz
 	musl-find_library.patch
+	issue-27955.patch
 	"
 builddir="$srcdir/Python-$pkgver"
 
@@ -93,8 +94,11 @@ tkinter() {
 }
 
 md5sums="8906efbacfcdc7c3c9198aeefafd159e  Python-3.5.2.tar.xz
-2840477c6552a0ca2f4ede885ad872f1  musl-find_library.patch"
+2840477c6552a0ca2f4ede885ad872f1  musl-find_library.patch
+b63a796d0662515d7abe1e94576ced1d  issue-27955.patch"
 sha256sums="0010f56100b9b74259ebcd5d4b295a32324b58b517403a10d1a2aa7cb22bca40  Python-3.5.2.tar.xz
-83fd071bc556d4e88373a35fde74cb9c464ee4b8e95e5583b55f2e36d4f33cf2  musl-find_library.patch"
+83fd071bc556d4e88373a35fde74cb9c464ee4b8e95e5583b55f2e36d4f33cf2  musl-find_library.patch
+61ea7a484332c245f0fccdbe93597efd91e3613a495d7172627a47b85dd8d088  issue-27955.patch"
 sha512sums="c07c3366f1c81e214241444bb9da6db9d11da32ad66bfa29cdad5a3b2e34e4d870bda6d4ce3c3910b582942e91f1d8c8a1c1a7b9464cc147b83c9e0007012742  Python-3.5.2.tar.xz
-ab8eaa2858d5109049b1f9f553198d40e0ef8d78211ad6455f7b491af525bffb16738fed60fc84e960c4889568d25753b9e4a1494834fea48291b33f07000ec2  musl-find_library.patch"
+ab8eaa2858d5109049b1f9f553198d40e0ef8d78211ad6455f7b491af525bffb16738fed60fc84e960c4889568d25753b9e4a1494834fea48291b33f07000ec2  musl-find_library.patch
+388a0f49e98daf953bf859c15cc43f71dc7d77e82e65cb14a51999e8dd78cf93636ab5c116148c6310a8ea93a7c6d03fcd35e1b8f023d8e94fcff637b6c47c54  issue-27955.patch"
diff --git a/main/python3/issue-27955.patch b/main/python3/issue-27955.patch
new file mode 100644
index 0000000000..c0d7c21061
--- /dev/null
+++ b/main/python3/issue-27955.patch
@@ -0,0 +1,258 @@
+From 079c591fefa308803535e6529689a8583bbc2efa Mon Sep 17 00:00:00 2001
+From: Victor Stinner <victor.stinner@gmail.com>
+Date: Tue, 20 Sep 2016 22:26:18 +0200
+Subject: [PATCH] Cleanup random.c
+
+Issue #27955: modify py_getrnadom() and dev_urandom()
+
+* Add comments from Python 3.7
+* PEP 7 style: add {...}
+---
+ Python/random.c | 81 +++++++++++++++++++++++++++++++++++++--------------------
+ 1 file changed, 53 insertions(+), 28 deletions(-)
+
+diff --git a/Python/random.c b/Python/random.c
+index 3119872..5582e39 100644
+--- a/Python/random.c
++++ b/Python/random.c
+@@ -119,11 +119,20 @@ py_getentropy(unsigned char *buffer, Py_ssize_t size, int fatal)
+ #if defined(HAVE_GETRANDOM) || defined(HAVE_GETRANDOM_SYSCALL)
+ #define PY_GETRANDOM 1
+ 
++/* Call getrandom()
++   - Return 1 on success
++   - Return 0 if getrandom() syscall is not available (failed with ENOSYS)
++     or if getrandom(GRND_NONBLOCK) failed with EAGAIN (system urandom
++     not initialized yet) and raise=0.
++   - 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. */
+ 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 newer, or Solaris 11.3 or newer */
++    /* Is getrandom() supported by the running kernel? Set to 0 if getrandom()
++       failed with ENOSYS. Need Linux kernel 3.17 or newer, or Solaris
++       11.3 or newer */
+     static int getrandom_works = 1;
+ 
+     /* getrandom() on Linux will block if called before the kernel has
+@@ -134,8 +143,9 @@ py_getrandom(void *buffer, Py_ssize_t size, int raise)
+     const int flags = GRND_NONBLOCK;
+     long n;
+ 
+-    if (!getrandom_works)
++    if (!getrandom_works) {
+         return 0;
++    }
+ 
+     while (0 < size) {
+ #ifdef sun
+@@ -171,36 +181,42 @@ py_getrandom(void *buffer, Py_ssize_t size, int raise)
+ #endif
+ 
+         if (n < 0) {
++            /* ENOSYS: getrandom() syscall not supported by the kernel (but
++             * maybe supported by the host which built Python). */
+             if (errno == ENOSYS) {
+                 getrandom_works = 0;
+                 return 0;
+             }
+             if (errno == EAGAIN) {
+-                /* If we failed with EAGAIN, the entropy pool was
+-                 * uninitialized. In this case, we return failure to fall
+-                 * back to reading from /dev/urandom.
+-                 *
+-                 * Note: In this case the data read will not be random so
+-                 * should not be used for cryptographic purposes. Retaining
+-                 * the existing semantics for practical purposes. */
++                /* getrandom(GRND_NONBLOCK) fails with EAGAIN if the system
++                   urandom is not initialiazed yet. In this case, fall back on
++                   reading from /dev/urandom.
++
++                   Note: In this case the data read will not be random so
++                   should not be used for cryptographic purposes. Retaining
++                   the existing semantics for practical purposes. */
+                 getrandom_works = 0;
+                 return 0;
+             }
+ 
+             if (errno == EINTR) {
+                 if (PyErr_CheckSignals()) {
+-                    if (!raise)
++                    if (!raise) {
+                         Py_FatalError("getrandom() interrupted by a signal");
++                    }
+                     return -1;
+                 }
++
+                 /* retry getrandom() */
+                 continue;
+             }
+ 
+-            if (raise)
++            if (raise) {
+                 PyErr_SetFromErrno(PyExc_OSError);
+-            else
++            }
++            else {
+                 Py_FatalError("getrandom() failed");
++            }
+             return -1;
+         }
+ 
+@@ -218,7 +234,9 @@ static struct {
+ } urandom_cache = { -1 };
+ 
+ 
+-/* Read size bytes from /dev/urandom into buffer.
++/* Read 'size' random bytes from py_getrandom(). Fall back on reading from
++   /dev/urandom if getrandom() is not available.
++
+    Call Py_FatalError() on error. */
+ static void
+ dev_urandom_noraise(unsigned char *buffer, Py_ssize_t size)
+@@ -229,24 +247,26 @@ dev_urandom_noraise(unsigned char *buffer, Py_ssize_t size)
+     assert (0 < size);
+ 
+ #ifdef PY_GETRANDOM
+-    if (py_getrandom(buffer, size, 0) == 1)
++    if (py_getrandom(buffer, size, 0) == 1) {
+         return;
+-    /* getrandom() is not supported by the running kernel, fall back
+-     * on reading /dev/urandom */
++    }
++    /* getrandom() failed with ENOSYS,
++       fall back on reading /dev/urandom */
+ #endif
+ 
+     fd = _Py_open_noraise("/dev/urandom", O_RDONLY);
+-    if (fd < 0)
++    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)
+-        {
+-            /* stop on error or if read(size) returned 0 */
++
++        if (n <= 0) {
++            /* read() failed or returned 0 bytes */
+             Py_FatalError("Failed to read bytes from /dev/urandom");
+             break;
+         }
+@@ -256,8 +276,10 @@ dev_urandom_noraise(unsigned char *buffer, Py_ssize_t size)
+     close(fd);
+ }
+ 
+-/* Read size bytes from /dev/urandom into buffer.
+-   Return 0 on success, raise an exception and return -1 on error. */
++/* 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)
+ {
+@@ -273,12 +295,14 @@ dev_urandom_python(char *buffer, Py_ssize_t size)
+ 
+ #ifdef PY_GETRANDOM
+     res = py_getrandom(buffer, size, 1);
+-    if (res < 0)
++    if (res < 0) {
+         return -1;
+-    if (res == 1)
++    }
++    if (res == 1) {
+         return 0;
+-    /* getrandom() is not supported by the running kernel, fall back
+-     * on reading /dev/urandom */
++    }
++    /* getrandom() failed with ENOSYS,
++       fall back on reading /dev/urandom */
+ #endif
+ 
+     if (urandom_cache.fd >= 0) {
+@@ -325,8 +349,9 @@ dev_urandom_python(char *buffer, Py_ssize_t size)
+ 
+     do {
+         n = _Py_read(fd, buffer, (size_t)size);
+-        if (n == -1)
++        if (n == -1) {
+             return -1;
++        }
+         if (n == 0) {
+             PyErr_Format(PyExc_RuntimeError,
+                     "Failed to read %zi bytes from /dev/urandom",
+From 2b9aca0055805921cd8783bb3ac2cccfa20e83dc Mon Sep 17 00:00:00 2001
+From: Victor Stinner <victor.stinner@gmail.com>
+Date: Tue, 20 Sep 2016 22:46:02 +0200
+Subject: [PATCH] Catch EPERM error in py_getrandom()
+
+Issue #27955: Fallback on reading /dev/urandom device when the getrandom()
+syscall fails with EPERM, for example when blocked by SECCOMP.
+---
+ Misc/NEWS       |  3 +++
+ Python/random.c | 15 ++++++++-------
+ 2 files changed, 11 insertions(+), 7 deletions(-)
+
+diff --git a/Python/random.c b/Python/random.c
+index 5582e39..f2ada5f 100644
+--- a/Python/random.c
++++ b/Python/random.c
+@@ -121,8 +121,8 @@ py_getentropy(unsigned char *buffer, Py_ssize_t size, int fatal)
+ 
+ /* Call getrandom()
+    - Return 1 on success
+-   - Return 0 if getrandom() syscall is not available (failed with ENOSYS)
+-     or if getrandom(GRND_NONBLOCK) failed with EAGAIN (system urandom
++   - 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.
+    - Raise an exception (if raise is non-zero) and return -1 on error:
+      getrandom() failed with EINTR and the Python signal handler raised an
+@@ -131,7 +131,7 @@ static int
+ py_getrandom(void *buffer, Py_ssize_t size, int raise)
+ {
+     /* Is getrandom() supported by the running kernel? Set to 0 if getrandom()
+-       failed with ENOSYS. Need Linux kernel 3.17 or newer, or Solaris
++       failed with ENOSYS or EPERM. Need Linux kernel 3.17 or newer, or Solaris
+        11.3 or newer */
+     static int getrandom_works = 1;
+ 
+@@ -182,8 +182,9 @@ py_getrandom(void *buffer, Py_ssize_t size, int raise)
+ 
+         if (n < 0) {
+             /* ENOSYS: getrandom() syscall not supported by the kernel (but
+-             * maybe supported by the host which built Python). */
+-            if (errno == ENOSYS) {
++             * maybe supported by the host which built Python). EPERM:
++             * getrandom() syscall blocked by SECCOMP or something else. */
++            if (errno == ENOSYS || errno == EPERM) {
+                 getrandom_works = 0;
+                 return 0;
+             }
+@@ -250,7 +251,7 @@ dev_urandom_noraise(unsigned char *buffer, Py_ssize_t size)
+     if (py_getrandom(buffer, size, 0) == 1) {
+         return;
+     }
+-    /* getrandom() failed with ENOSYS,
++    /* getrandom() failed with ENOSYS or EPERM,
+        fall back on reading /dev/urandom */
+ #endif
+ 
+@@ -301,7 +302,7 @@ dev_urandom_python(char *buffer, Py_ssize_t size)
+     if (res == 1) {
+         return 0;
+     }
+-    /* getrandom() failed with ENOSYS,
++    /* getrandom() failed with ENOSYS or EPERM,
+        fall back on reading /dev/urandom */
+ #endif
+