[Pkg-gnupg-commit] [gpgme] 116/412: python: Robust exception handling in callbacks.
Daniel Kahn Gillmor
dkg at fifthhorseman.net
Thu Sep 22 21:26:28 UTC 2016
This is an automated email from the git hooks/post-receive script.
dkg pushed a commit to branch master
in repository gpgme.
commit d90857a08c4fe5b73b6d6d46fd6200efdd72db44
Author: Justus Winter <justus at gnupg.org>
Date: Thu May 19 11:03:27 2016 +0200
python: Robust exception handling in callbacks.
* lang/python/helpers.c (pygpgme_stash_callback_exception): New
function.
(pygpgme_raise_callback_exception): Likewise.
(pyPassphraseCb): Stash python errors.
* lang/python/helpers.h (pygpgme_raise_callback_exception): New
prototype.
* lang/python/pyme/core.py ({Context,Data}.__init__): Move common
initialization to superclass.
(Context.set_progress_cb): Hand in 'self'.
* lang/python/pyme/util.py (GpgmeWrapper.__init__): New function.
(GpgmeWrapper.__getattr__): Raise stashed exceptions.
* lang/python/tests/Makefile.am (py_tests): Add new test.
* lang/python/tests/t-callbacks.py: New file.
Signed-off-by: Justus Winter <justus at gnupg.org>
---
lang/python/helpers.c | 95 +++++++++++++++++++++++++++++++++++++---
lang/python/helpers.h | 1 +
lang/python/pyme/core.py | 10 ++---
lang/python/pyme/util.py | 16 +++++--
lang/python/tests/Makefile.am | 1 +
lang/python/tests/t-callbacks.py | 77 ++++++++++++++++++++++++++++++++
6 files changed, 187 insertions(+), 13 deletions(-)
diff --git a/lang/python/helpers.c b/lang/python/helpers.c
index 447a29f..c3cf3b3 100644
--- a/lang/python/helpers.c
+++ b/lang/python/helpers.c
@@ -17,6 +17,8 @@
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+
+#include <assert.h>
#include <stdio.h>
#include <gpgme.h>
#include <stdlib.h>
@@ -59,12 +61,84 @@ void pygpgme_clear_generic_cb(PyObject **cb) {
Py_DECREF(*cb);
}
+/* Exception support for callbacks. */
+#define EXCINFO "_callback_excinfo"
+
+static void pygpgme_stash_callback_exception(PyObject *self)
+{
+ PyObject *ptype, *pvalue, *ptraceback, *excinfo;
+
+ PyErr_Fetch(&ptype, &pvalue, &ptraceback);
+ excinfo = PyTuple_New(3);
+ PyTuple_SetItem(excinfo, 0, ptype);
+
+ if (pvalue)
+ PyTuple_SetItem(excinfo, 1, pvalue);
+ else {
+ Py_INCREF(Py_None);
+ PyTuple_SetItem(excinfo, 1, Py_None);
+ }
+
+ if (ptraceback)
+ PyTuple_SetItem(excinfo, 2, ptraceback);
+ else {
+ Py_INCREF(Py_None);
+ PyTuple_SetItem(excinfo, 2, Py_None);
+ }
+
+ PyObject_SetAttrString(self, EXCINFO, excinfo);
+}
+
+PyObject *pygpgme_raise_callback_exception(PyObject *self)
+{
+ PyObject *ptype, *pvalue, *ptraceback, *excinfo;
+
+ if (! PyObject_HasAttrString(self, EXCINFO))
+ goto leave;
+
+ excinfo = PyObject_GetAttrString(self, EXCINFO);
+ if (! PyTuple_Check(excinfo))
+ {
+ Py_DECREF(excinfo);
+ goto leave;
+ }
+
+ ptype = PyTuple_GetItem(excinfo, 0);
+ Py_INCREF(excinfo);
+
+ pvalue = PyTuple_GetItem(excinfo, 1);
+ if (pvalue == Py_None)
+ pvalue = NULL;
+ else
+ Py_INCREF(pvalue);
+
+ ptraceback = PyTuple_GetItem(excinfo, 2);
+ if (ptraceback == Py_None)
+ ptraceback = NULL;
+ else
+ Py_INCREF(ptraceback);
+
+ Py_DECREF(excinfo);
+ PyErr_Restore(ptype, pvalue, ptraceback);
+
+ Py_INCREF(Py_None);
+ PyObject_SetAttrString(self, EXCINFO, Py_None);
+
+ return NULL; /* Raise exception. */
+
+ leave:
+ Py_INCREF(Py_None);
+ return Py_None;
+}
+#undef EXCINFO
+
static gpgme_error_t pyPassphraseCb(void *hook,
const char *uid_hint,
const char *passphrase_info,
int prev_was_bad,
int fd) {
PyObject *pyhook = (PyObject *) hook;
+ PyObject *self = NULL;
PyObject *func = NULL;
PyObject *args = NULL;
PyObject *retval = NULL;
@@ -73,12 +147,13 @@ static gpgme_error_t pyPassphraseCb(void *hook,
pygpgme_exception_init();
- if (PyTuple_Check(pyhook)) {
- func = PyTuple_GetItem(pyhook, 0);
- dataarg = PyTuple_GetItem(pyhook, 1);
+ assert (PyTuple_Check(pyhook));
+ self = PyTuple_GetItem(pyhook, 0);
+ func = PyTuple_GetItem(pyhook, 1);
+ if (PyTuple_Size(pyhook) == 3) {
+ dataarg = PyTuple_GetItem(pyhook, 2);
args = PyTuple_New(4);
} else {
- func = pyhook;
args = PyTuple_New(3);
}
@@ -90,6 +165,11 @@ static gpgme_error_t pyPassphraseCb(void *hook,
else
PyTuple_SetItem(args, 0, PyUnicode_DecodeUTF8(uid_hint, strlen (uid_hint),
"strict"));
+ if (PyErr_Occurred()) {
+ Py_DECREF(args);
+ err_status = gpg_error(GPG_ERR_GENERAL);
+ goto leave;
+ }
PyTuple_SetItem(args, 1, PyBytes_FromString(passphrase_info));
PyTuple_SetItem(args, 2, PyBool_FromLong((long)prev_was_bad));
@@ -117,7 +197,8 @@ static gpgme_error_t pyPassphraseCb(void *hook,
PyErr_Format(PyExc_TypeError,
"expected str or bytes from passphrase callback, got %s",
retval->ob_type->tp_name);
- return gpg_error(GPG_ERR_GENERAL);
+ err_status = gpg_error(GPG_ERR_GENERAL);
+ goto leave;
}
write(fd, buf, len);
@@ -126,6 +207,10 @@ static gpgme_error_t pyPassphraseCb(void *hook,
}
}
+ leave:
+ if (err_status)
+ pygpgme_stash_callback_exception(self);
+
return err_status;
}
diff --git a/lang/python/helpers.h b/lang/python/helpers.h
index 12d7cfa..81d17ff 100644
--- a/lang/python/helpers.h
+++ b/lang/python/helpers.h
@@ -30,6 +30,7 @@ void pygpgme_exception_init(void);
gpgme_error_t pygpgme_exception2code(void);
void pygpgme_clear_generic_cb(PyObject **cb);
+PyObject *pygpgme_raise_callback_exception(PyObject *self);
void pygpgme_set_passphrase_cb(gpgme_ctx_t ctx, PyObject *cb,
PyObject **freelater);
diff --git a/lang/python/pyme/core.py b/lang/python/pyme/core.py
index 2a0ca07..8a4c197 100644
--- a/lang/python/pyme/core.py
+++ b/lang/python/pyme/core.py
@@ -54,14 +54,14 @@ class Context(GpgmeWrapper):
def __init__(self, wrapped=None):
if wrapped:
- self.wrapped = wrapped
self.own = False
else:
tmp = pygpgme.new_gpgme_ctx_t_p()
errorcheck(pygpgme.gpgme_new(tmp))
- self.wrapped = pygpgme.gpgme_ctx_t_p_value(tmp)
+ wrapped = pygpgme.gpgme_ctx_t_p_value(tmp)
pygpgme.delete_gpgme_ctx_t_p(tmp)
self.own = True
+ super().__init__(wrapped)
self.last_passcb = None
self.last_progresscb = None
@@ -167,9 +167,9 @@ class Context(GpgmeWrapper):
else:
self.last_passcb = pygpgme.new_PyObject_p_p()
if hook == None:
- hookdata = func
+ hookdata = (self, func)
else:
- hookdata = (func, hook)
+ hookdata = (self, func, hook)
pygpgme.pygpgme_set_passphrase_cb(self.wrapped, hookdata, self.last_passcb)
def set_progress_cb(self, func, hook=None):
@@ -282,7 +282,7 @@ class Data(GpgmeWrapper):
that file.
Any other use will result in undefined or erroneous behavior."""
- self.wrapped = None
+ super().__init__(None)
self.last_readcb = None
if cbs != None:
diff --git a/lang/python/pyme/util.py b/lang/python/pyme/util.py
index 3c34c79..b54cd4d 100644
--- a/lang/python/pyme/util.py
+++ b/lang/python/pyme/util.py
@@ -32,6 +32,11 @@ def process_constants(starttext, dict):
class GpgmeWrapper(object):
"""Base class all Pyme wrappers for GPGME functionality. Not to be
instantiated directly."""
+
+ def __init__(self, wrapped):
+ self._callback_excinfo = None
+ self.wrapped = wrapped
+
def __repr__(self):
return '<instance of %s.%s with GPG object at %s>' % \
(__name__, self.__class__.__name__,
@@ -78,11 +83,16 @@ class GpgmeWrapper(object):
if self._errorcheck(name):
def _funcwrap(slf, *args, **kwargs):
- return errorcheck(func(slf.wrapped, *args, **kwargs),
- "Invocation of " + name)
+ result = func(slf.wrapped, *args, **kwargs)
+ if slf._callback_excinfo:
+ pygpgme.pygpgme_raise_callback_exception(slf)
+ return errorcheck(result, "Invocation of " + name)
else:
def _funcwrap(slf, *args, **kwargs):
- return func(slf.wrapped, *args, **kwargs)
+ result = func(slf.wrapped, *args, **kwargs)
+ if slf._callback_excinfo:
+ pygpgme.pygpgme_raise_callback_exception(slf)
+ return result
_funcwrap.__doc__ = getattr(func, "__doc__")
diff --git a/lang/python/tests/Makefile.am b/lang/python/tests/Makefile.am
index c4fc602..30f1aec 100644
--- a/lang/python/tests/Makefile.am
+++ b/lang/python/tests/Makefile.am
@@ -29,6 +29,7 @@ TESTS_ENVIRONMENT = GNUPGHOME=$(abs_builddir) \
PYTHONPATH=`echo $(abs_builddir)/../build/lib.*`
py_tests = t-wrapper.py \
+ t-callbacks.py \
t-data.py \
t-encrypt.py \
t-encrypt-sym.py \
diff --git a/lang/python/tests/t-callbacks.py b/lang/python/tests/t-callbacks.py
new file mode 100755
index 0000000..e89fcb8
--- /dev/null
+++ b/lang/python/tests/t-callbacks.py
@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+
+# Copyright (C) 2016 g10 Code GmbH
+#
+# This file is part of GPGME.
+#
+# GPGME is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# GPGME is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
+# Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, see <http://www.gnu.org/licenses/>.
+
+import os
+from pyme import core, constants
+import support
+
+support.init_gpgme(constants.PROTOCOL_OpenPGP)
+
+c = core.Context()
+c.set_pinentry_mode(constants.PINENTRY_MODE_LOOPBACK)
+
+source = core.Data("Hallo Leute\n")
+sink = core.Data()
+
+# Valid passphrases, both as string and bytes.
+for passphrase in ('foo', b'foo'):
+ def passphrase_cb(hint, desc, prev_bad, hook=None):
+ assert hook == passphrase
+ return hook
+
+ c.set_passphrase_cb(passphrase_cb, passphrase)
+ c.op_encrypt([], 0, source, sink)
+
+# Returning an invalid type.
+def passphrase_cb(hint, desc, prev_bad, hook=None):
+ return 0
+
+c.set_passphrase_cb(passphrase_cb, None)
+try:
+ c.op_encrypt([], 0, source, sink)
+except Exception as e:
+ assert type(e) == TypeError
+ assert str(e) == "expected str or bytes from passphrase callback, got int"
+else:
+ assert False, "Expected an error, got none"
+
+# Raising an exception inside callback.
+myException = Exception()
+def passphrase_cb(hint, desc, prev_bad, hook=None):
+ raise myException
+
+c.set_passphrase_cb(passphrase_cb, None)
+try:
+ c.op_encrypt([], 0, source, sink)
+except Exception as e:
+ assert e == myException
+else:
+ assert False, "Expected an error, got none"
+
+# Wrong kind of callback function.
+def bad_passphrase_cb():
+ pass
+
+c.set_passphrase_cb(bad_passphrase_cb, None)
+try:
+ c.op_encrypt([], 0, source, sink)
+except Exception as e:
+ assert type(e) == TypeError
+else:
+ assert False, "Expected an error, got none"
--
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