From: Mark Wooding <mdw@distorted.org.uk>
Date: Thu, 11 May 2017 09:42:15 +0000 (+0100)
Subject: pubkey.c: Factor out commonality between X25519 and X448.
X-Git-Tag: 1.2.0~9
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/catacomb-python/commitdiff_plain/34bea1860bbbf768746ccacdd608e1a68ff01c01?ds=sidebyside;hp=-c

pubkey.c: Factor out commonality between X25519 and X448.
---

34bea1860bbbf768746ccacdd608e1a68ff01c01
diff --git a/pubkey.c b/pubkey.c
index 4067ae0..5611508 100644
--- a/pubkey.c
+++ b/pubkey.c
@@ -1137,37 +1137,29 @@ end:
 
 /*----- X25519 and related algorithms -------------------------------------*/
 
-static PyObject *meth_x25519(PyObject *me, PyObject *arg)
-{
-  const char *k, *p;
-  Py_ssize_t ksz, psz;
-  PyObject *rc = 0;
-  if (!PyArg_ParseTuple(arg, "s#s#:x25519", &k, &ksz, &p, &psz)) goto end;
-  if (ksz != X25519_KEYSZ) VALERR("bad key length");
-  if (psz != X25519_PUBSZ) VALERR("bad public length");
-  rc = bytestring_pywrap(0, X25519_OUTSZ);
-  x25519((octet *)PyString_AS_STRING(rc),
-	 (const octet *)k, (const octet *)p);
-  return (rc);
-end:
-  return (0);
-}
-
-static PyObject *meth_x448(PyObject *me, PyObject *arg)
-{
-  const char *k, *p;
-  Py_ssize_t ksz, psz;
-  PyObject *rc = 0;
-  if (!PyArg_ParseTuple(arg, "s#s#:x448", &k, &ksz, &p, &psz)) goto end;
-  if (ksz != X448_KEYSZ) VALERR("bad key length");
-  if (psz != X448_PUBSZ) VALERR("bad public length");
-  rc = bytestring_pywrap(0, X448_OUTSZ);
-  x448((octet *)PyString_AS_STRING(rc),
-       (const octet *)k, (const octet *)p);
-  return (rc);
-end:
-  return (0);
-}
+#define XDHS(_)								\
+  _(X25519, x25519)							\
+  _(X448, x448)
+
+#define DEFXDH(X, x)							\
+  static PyObject *meth_##x(PyObject *me, PyObject *arg)		\
+  {									\
+    const char *k, *p;							\
+    Py_ssize_t ksz, psz;						\
+    PyObject *rc = 0;							\
+    if (!PyArg_ParseTuple(arg, "s#s#:" #x, &k, &ksz, &p, &psz))		\
+      goto end;								\
+    if (ksz != X##_KEYSZ) VALERR("bad key length");			\
+    if (psz != X##_PUBSZ) VALERR("bad public length");			\
+    rc = bytestring_pywrap(0, X##_OUTSZ);				\
+    x((octet *)PyString_AS_STRING(rc),					\
+      (const octet *)k, (const octet *)p);				\
+    return (rc);							\
+  end:									\
+    return (0);								\
+  }
+XDHS(DEFXDH)
+#undef DEFXDH
 
 /*----- Ed25519 -----------------------------------------------------------*/
 
@@ -1234,10 +1226,11 @@ static PyMethodDef methods[] = {
   KWMETH(_pss_decode,			0)
   KWMETH(_RSAPriv_generate,		"\
 generate(NBITS, [event = pgen_nullev, rng = rand, nsteps = 0]) -> R")
-  METH  (x25519,			"\
-x25519(KEY, PUBLIC) -> SHARED")
-  METH  (x448,				"\
-x448(KEY, PUBLIC) -> SHARED")
+#define DEFMETH(X, x)							\
+  METH  (x,				"\
+" #x "(KEY, PUBLIC) -> SHARED")
+  XDHS(DEFMETH)
+#undef DEFMETH
   METH  (ed25519_pubkey,		"\
 ed25519_pubkey(KEY) -> PUBLIC")
   KWMETH(ed25519_sign,			"\