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# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.
from __future__ import absolute_import, division, print_function
import json
import os
import subprocess
import sys
import textwrap
import pytest
from cryptography.hazmat.bindings.openssl.binding import Binding
MEMORY_LEAK_SCRIPT = """
import sys
def main(argv):
import gc
import json
from cryptography.hazmat.bindings._openssl import ffi, lib
heap = {}
@ffi.callback("void *(size_t, const char *, int)")
def malloc(size, path, line):
ptr = lib.Cryptography_malloc_wrapper(size, path, line)
heap[ptr] = (size, path, line)
return ptr
@ffi.callback("void *(void *, size_t, const char *, int)")
def realloc(ptr, size, path, line):
if ptr != ffi.NULL:
del heap[ptr]
new_ptr = lib.Cryptography_realloc_wrapper(ptr, size, path, line)
heap[new_ptr] = (size, path, line)
return new_ptr
@ffi.callback("void(void *, const char *, int)")
def free(ptr, path, line):
if ptr != ffi.NULL:
del heap[ptr]
lib.Cryptography_free_wrapper(ptr, path, line)
result = lib.Cryptography_CRYPTO_set_mem_functions(malloc, realloc, free)
assert result == 1
# Trigger a bunch of initialization stuff.
import cryptography.hazmat.backends.openssl
start_heap = set(heap)
func(*argv[1:])
gc.collect()
gc.collect()
gc.collect()
# Swap back to the original functions so that if OpenSSL tries to free
# something from its atexit handle it won't be going through a Python
# function, which will be deallocated when this function returns
result = lib.Cryptography_CRYPTO_set_mem_functions(
ffi.addressof(lib, "Cryptography_malloc_wrapper"),
ffi.addressof(lib, "Cryptography_realloc_wrapper"),
ffi.addressof(lib, "Cryptography_free_wrapper"),
)
assert result == 1
remaining = set(heap) - start_heap
if remaining:
sys.stdout.write(json.dumps(dict(
(int(ffi.cast("size_t", ptr)), {
"size": heap[ptr][0],
"path": ffi.string(heap[ptr][1]).decode(),
"line": heap[ptr][2],
})
for ptr in remaining
)))
sys.stdout.flush()
sys.exit(255)
main(sys.argv)
"""
def assert_no_memory_leaks(s, argv=[]):
env = os.environ.copy()
env["PYTHONPATH"] = os.pathsep.join(sys.path)
argv = [
sys.executable, "-c", "{0}\n\n{1}".format(s, MEMORY_LEAK_SCRIPT)
] + argv
# Shell out to a fresh Python process because OpenSSL does not allow you to
# install new memory hooks after the first malloc/free occurs.
proc = subprocess.Popen(
argv,
env=env,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
)
proc.wait()
if proc.returncode == 255:
# 255 means there was a leak, load the info about what mallocs weren't
# freed.
out = json.loads(proc.stdout.read().decode())
raise AssertionError(out)
elif proc.returncode != 0:
# Any exception type will do to be honest
raise ValueError(proc.stdout.read(), proc.stderr.read())
def skip_if_memtesting_not_supported():
return pytest.mark.skipif(
not Binding().lib.Cryptography_HAS_MEM_FUNCTIONS,
reason="Requires OpenSSL memory functions (>=1.1.0)"
)
@skip_if_memtesting_not_supported()
class TestAssertNoMemoryLeaks(object):
def test_no_leak_no_malloc(self):
assert_no_memory_leaks(textwrap.dedent("""
def func():
pass
"""))
def test_no_leak_free(self):
assert_no_memory_leaks(textwrap.dedent("""
def func():
from cryptography.hazmat.bindings.openssl.binding import Binding
b = Binding()
name = b.lib.X509_NAME_new()
b.lib.X509_NAME_free(name)
"""))
def test_no_leak_gc(self):
assert_no_memory_leaks(textwrap.dedent("""
def func():
from cryptography.hazmat.bindings.openssl.binding import Binding
b = Binding()
name = b.lib.X509_NAME_new()
b.ffi.gc(name, b.lib.X509_NAME_free)
"""))
def test_leak(self):
with pytest.raises(AssertionError):
assert_no_memory_leaks(textwrap.dedent("""
def func():
from cryptography.hazmat.bindings.openssl.binding import (
Binding
)
b = Binding()
b.lib.X509_NAME_new()
"""))
def test_errors(self):
with pytest.raises(ValueError):
assert_no_memory_leaks(textwrap.dedent("""
def func():
raise ZeroDivisionError
"""))
@skip_if_memtesting_not_supported()
class TestOpenSSLMemoryLeaks(object):
@pytest.mark.parametrize("path", [
"x509/PKITS_data/certs/ValidcRLIssuerTest28EE.crt",
])
def test_x509_extensions(self, path):
assert_no_memory_leaks(textwrap.dedent("""
def func(path):
from cryptography import x509
from cryptography.hazmat.backends.openssl import backend
import cryptography_vectors
with cryptography_vectors.open_vector_file(path, "rb") as f:
cert = x509.load_der_x509_certificate(
f.read(), backend
)
cert.extensions
"""), [path])
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