Skip to content

[3.7] bpo-33136: Harden ssl module against CVE-2018-8970 (GH-6229) #6230

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
tiran merged 1 commit into from
Mar 25, 2018
Merged

[3.7] bpo-33136: Harden ssl module against CVE-2018-8970 (GH-6229) #6230

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions Lib/test/test_ssl.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1660,6 +1660,9 @@ def test_bad_server_hostname(self):
with self.assertRaises(ValueError):
ctx.wrap_bio(ssl.MemoryBIO(), ssl.MemoryBIO(),
server_hostname=".example.org")
with self.assertRaises(TypeError):
ctx.wrap_bio(ssl.MemoryBIO(), ssl.MemoryBIO(),
server_hostname="example.org\x00evil.com")


class MemoryBIOTests(unittest.TestCase):
Expand Down
3 changes: 3 additions & 0 deletions Misc/NEWS.d/next/Security/2018-03-25-12-05-43.bpo-33136.TzSN4x.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
Harden ssl module against LibreSSL CVE-2018-8970.
X509_VERIFY_PARAM_set1_host() is called with an explicit namelen. A new test
ensures that NULL bytes are not allowed.
7 changes: 4 additions & 3 deletions Modules/_ssl.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -852,7 +852,8 @@ _ssl_configure_hostname(PySSLSocket *self, const char* server_hostname)
if (self->ctx->check_hostname) {
X509_VERIFY_PARAM *param = SSL_get0_param(self->ssl);
if (ip == NULL) {
if (!X509_VERIFY_PARAM_set1_host(param, server_hostname, 0)) {
if (!X509_VERIFY_PARAM_set1_host(param, server_hostname,
strlen(server_hostname))) {
_setSSLError(NULL, 0, __FILE__, __LINE__);
goto error;
}
Expand Down Expand Up @@ -4025,7 +4026,7 @@ _ssl__SSLContext__wrap_socket_impl(PySSLContext *self, PyObject *sock,
PyObject *res;

/* server_hostname is either None (or absent), or to be encoded
as IDN A-label (ASCII str). */
as IDN A-label (ASCII str) without NULL bytes. */
if (hostname_obj != Py_None) {
if (!PyArg_Parse(hostname_obj, "es", "ascii", &hostname))
return NULL;
Expand Down Expand Up @@ -4063,7 +4064,7 @@ _ssl__SSLContext__wrap_bio_impl(PySSLContext *self, PySSLMemoryBIO *incoming,
PyObject *res;

/* server_hostname is either None (or absent), or to be encoded
as IDN A-label (ASCII str). */
as IDN A-label (ASCII str) without NULL bytes. */
if (hostname_obj != Py_None) {
if (!PyArg_Parse(hostname_obj, "es", "ascii", &hostname))
return NULL;
Expand Down