fixes for Python 3.10

.github/workflows/ci.yaml

@@ -0,0 +1,33 @@
+name: pykerberos CI
+on:
+  push:
+  pull_request:
+
+jobs:
+  linux:
+    runs-on: ubuntu-20.04
+    strategy:
+      matrix:
+        include:
+        - python: 2.7
+        - python: 3.6
+        - python: 3.7
+        - python: 3.8
+        - python: 3.9
+        - python: '3.10'
+    steps:
+    - name: checkout
+      uses: actions/checkout@v2
+
+    - name: install Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python }}
+
+    - name: test build/install
+      run: |
+        sudo apt-get update -qq
+        sudo apt-get install libkrb5-dev
+
+        python -V
+        python -m pip install .

src/kerberos.c

@@ -14,6 +14,7 @@
  * limitations under the License.
  **/
 
+#define PY_SSIZE_T_CLEAN
 #include <Python.h>
 
 #include "kerberosbasic.h"
@@ -196,9 +197,9 @@ static PyObject *channelBindings(PyObject *self, PyObject *args, PyObject* keywd
     char *initiator_address = NULL;
     char *acceptor_address = NULL;
     char *application_data = NULL;
-    int initiator_length = 0;
-    int acceptor_length = 0;
-    int application_length = 0;
+    Py_ssize_t initiator_length = 0;
+    Py_ssize_t acceptor_length = 0;
+    Py_ssize_t application_length = 0;
 
     PyObject *pychan_bindings = NULL;
     struct gss_channel_bindings_struct *input_chan_bindings;