pubkey.c: Catch invalid arguments to `RSAPub' and `RSAPriv'.

If a modulus is even, `mpmont_create' will silently fail inside
`rsa_{pub,priv}create' and a later modexp will likely segfault.

diff --git a/pubkey.c b/pubkey.c
index c47f1b514cda3403b5b885b86cd927d76b2c21e4..8790e4083a518c64d20ca07c7f4e251ed1f16183 100644 (file)
--- a/pubkey.c
+++ b/pubkey.c
@@ -553,6 +553,7 @@ static PyObject *rsapub_pynew(PyTypeObject *ty,
   if (!PyArg_ParseTupleAndKeywords(arg, kw, "O&O&:new", kwlist,
                                   convmp, &rp.n, convmp, &rp.e))
     goto end;
+  if (!MP_ODDP(rp.n)) VALERR("RSA modulus must be even");
   o = (rsapub_pyobj *)ty->tp_alloc(ty, 0);
   o->pub = rp;
   rsa_pubcreate(&o->pubctx, &o->pub);
@@ -625,6 +626,10 @@ static PyObject *rsapriv_pynew(PyTypeObject *ty,
                                   convmp, &rp.q_inv,
                                   &rng))
     goto end;
+  if ((rp.n && !MP_ODDP(rp.n)) ||
+      (rp.p && !MP_ODDP(rp.p)) ||
+      (rp.p && !MP_ODDP(rp.q)))
+    VALERR("RSA modulus and factors must be odd");
   if (rsa_recover(&rp)) VALERR("couldn't construct private key");
   if (rng != Py_None && !GRAND_PYCHECK(rng))
     TYERR("not a random number source");