algorithms.c: Check whether `setiv' and `bdry' are implemented before calling.

Oops, easy segfault.

diff --git a/algorithms.c b/algorithms.c
index cb594ca31dd604f8297ea964b9457390f52ca89d..5b4f14b0e7d982922a8f0145efd1246c0269ada6 100644 (file)
--- a/algorithms.c
+++ b/algorithms.c
@@ -566,6 +566,7 @@ static PyObject *gcmeth_setiv(PyObject *me, PyObject *arg)
   Py_ssize_t sz;
 
   if (!PyArg_ParseTuple(arg, "s#:setiv", &p, &sz)) goto end;
+  if (!GCIPHER_C(me)->ops->setiv) VALERR("`setiv' not supported");
   if (!GC_CLASS(GCIPHER_C(me))->blksz) VALERR("not a block cipher mode");
   if (sz != GC_CLASS(GCIPHER_C(me))->blksz) VALERR("bad IV length");
   GC_SETIV(GCIPHER_C(me), p);
@@ -577,6 +578,7 @@ end:
 static PyObject *gcmeth_bdry(PyObject *me, PyObject *arg)
 {
   if (!PyArg_ParseTuple(arg, ":bdry")) goto end;
+  if (!GCIPHER_C(me)->ops->bdry) VALERR("`bdry' not supported");
   if (!GC_CLASS(GCIPHER_C(me))->blksz) VALERR("not a block cipher mode");
   GC_BDRY(GCIPHER_C(me));
   RETURN_ME;