From: Mark Wooding <mdw@distorted.org.uk>
Date: Fri, 6 Feb 2015 11:06:14 +0000 (+0000)
Subject: pubkey.c: Catch invalid arguments to `RSAPub' and `RSAPriv'.
X-Git-Tag: 1.1.0~23
X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb-python/commitdiff_plain/61cc9665df69b0641bfd40da285acbea20c48654

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 c47f1b5..8790e40 100644
--- 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");