pubkey.c: Change the arguments to {DSA,KCDSA}{Pub,Priv}.

  * Don't allow a private-key `u' argument to `*Pub'.

  * Have the private key argument `u' precede the public key `p' to
    `*Priv'.

  * Make the public key optional to `*Priv', and compute it correctly if
    not provided.

This is an incompatible change, but I've resolved not to care.  The old
interface was obviously crazy.

diff --git a/pubkey.c b/pubkey.c
index 5292717f5b4c0804783682a05f4c2876751cbc39..4067ae0ff10219ed5dbff4f24df93be1c4d41af7 100644 (file)
--- a/pubkey.c
+++ b/pubkey.c
@@ -54,26 +54,35 @@ static void dsa_pydealloc(PyObject *me)
 }
 
 static PyObject *dsa_setup(PyTypeObject *ty, PyObject *G, PyObject *u,
-                          PyObject *p, PyObject *rng, PyObject *hash)
+                          PyObject *p, PyObject *rng, PyObject *hash,
+                          void (*calcpub)(group *, ge *, mp *))
 {
   dsa_pyobj *g;
+  ge *pp;
 
   g = PyObject_New(dsa_pyobj, ty);
-  if (GROUP_G(G) != GE_G(p) && !group_samep(GROUP_G(G), GE_G(p)))
-    TYERR("public key not from group");
+  if (p) Py_INCREF(p);
   if (!u) {
     g->d.u = 0;
     u = Py_None;
   } else if ((g->d.u = getmp(u)) == 0)
     goto end;
+  if (!p) {
+    assert(g->d.u); assert(calcpub);
+    pp = G_CREATE(GROUP_G(G));
+    calcpub(GROUP_G(G), pp, g->d.u);
+    p = ge_pywrap(G, pp);
+  } else if (GROUP_G(G) != GE_G(p) && !group_samep(GROUP_G(G), GE_G(p)))
+    TYERR("public key not from group");
   g->d.g = GROUP_G(G);
   g->d.p = GE_X(p);
   g->d.r = GRAND_R(rng);
   g->d.h = GCHASH_CH(hash);
-  g->G = G; Py_INCREF(G); g->u = u; Py_INCREF(u); g->p = p; Py_INCREF(p);
+  g->G = G; Py_INCREF(G); g->u = u; Py_INCREF(u); g->p = p;
   g->rng = rng; Py_INCREF(rng); g->hash = hash; Py_INCREF(hash);
   return ((PyObject *)g);
 end:
+  if (p) Py_DECREF(p);
   FREEOBJ(g);
   return (0);
 }
@@ -81,17 +90,16 @@ end:
 static PyObject *dsapub_pynew(PyTypeObject *ty,
                              PyObject *arg, PyObject *kw)
 {
-  PyObject *G, *p, *u = 0, *rng = rand_pyobj, *hash = sha_pyobj;
+  PyObject *G, *p, *rng = rand_pyobj, *hash = sha_pyobj;
   PyObject *rc = 0;
-  char *kwlist[] = { "G", "p", "u", "hash", "rng", 0 };
+  char *kwlist[] = { "G", "p", "hash", "rng", 0 };
 
-  if (!PyArg_ParseTupleAndKeywords(arg, kw, "O!O!|OO!O!:new", kwlist,
+  if (!PyArg_ParseTupleAndKeywords(arg, kw, "O!O!|O!O!:new", kwlist,
                                   group_pytype, &G,
                                   ge_pytype, &p,
-                                  &u,
                                   gchash_pytype, &hash,
                                   grand_pytype, &rng) ||
-      (rc = dsa_setup(dsapub_pytype, G, u, p, rng, hash)) == 0)
+      (rc = dsa_setup(dsapub_pytype, G, 0, p, rng, hash, 0)) == 0)
     goto end;
 end:
   return (rc);
@@ -156,20 +164,22 @@ end:
   return (rc);
 }
 
+static void dsa_calcpub(group *g, ge *p, mp *u) { G_EXP(g, p, g->g, u); }
+
 static PyObject *dsapriv_pynew(PyTypeObject *ty,
                               PyObject *arg, PyObject *kw)
 {
-  PyObject *G, *p, *u = Py_None, *rng = rand_pyobj, *hash = sha_pyobj;
+  PyObject *G, *p = 0, *u, *rng = rand_pyobj, *hash = sha_pyobj;
   PyObject *rc = 0;
-  char *kwlist[] = { "G", "p", "u", "hash", "rng", 0 };
+  char *kwlist[] = { "G", "u", "p", "hash", "rng", 0 };
 
-  if (!PyArg_ParseTupleAndKeywords(arg, kw, "O!O!O|O!O!:new", kwlist,
+  if (!PyArg_ParseTupleAndKeywords(arg, kw, "O!O|O!O!O!:new", kwlist,
                                   group_pytype, &G,
-                                  ge_pytype, &p,
                                   &u,
+                                  ge_pytype, &p,
                                   gchash_pytype, &hash,
                                   grand_pytype, &rng) ||
-      (rc = dsa_setup(dsapriv_pytype, G, u, p, rng, hash)) == 0)
+      (rc = dsa_setup(dsapriv_pytype, G, u, p, rng, hash, dsa_calcpub)) == 0)
     goto end;
 end:
   return (rc);
@@ -307,36 +317,43 @@ static PyTypeObject dsapriv_pytype_skel = {
 static PyObject *kcdsapub_pynew(PyTypeObject *ty,
                                PyObject *arg, PyObject *kw)
 {
-  PyObject *G, *p, *u = 0, *rng = rand_pyobj, *hash = has160_pyobj;
+  PyObject *G, *p, *rng = rand_pyobj, *hash = has160_pyobj;
   PyObject *rc = 0;
-  char *kwlist[] = { "G", "p", "u", "hash", "rng", 0 };
+  char *kwlist[] = { "G", "p", "hash", "rng", 0 };
 
-  if (!PyArg_ParseTupleAndKeywords(arg, kw, "O!O!O|O!O!:new", kwlist,
+  if (!PyArg_ParseTupleAndKeywords(arg, kw, "O!O!|O!O!:new", kwlist,
                                   group_pytype, &G,
                                   ge_pytype, &p,
-                                  &u,
                                   gchash_pytype, &hash,
                                   grand_pytype, &rng) ||
-      (rc = dsa_setup(kcdsapub_pytype, G, u, p, rng, hash)) == 0)
+      (rc = dsa_setup(kcdsapub_pytype, G, 0, p, rng, hash, 0)) == 0)
     goto end;
 end:
   return (rc);
 }
 
+static void kcdsa_calcpub(group *g, ge *p, mp *u)
+{
+  mp *uinv = mp_modinv(MP_NEW, u, g->r);
+  G_EXP(g, p, g->g, uinv);
+  mp_drop(uinv);
+}
+
 static PyObject *kcdsapriv_pynew(PyTypeObject *ty,
                                 PyObject *arg, PyObject *kw)
 {
-  PyObject *G, *p, *u = Py_None, *rng = rand_pyobj, *hash = has160_pyobj;
+  PyObject *G, *u, *p = 0, *rng = rand_pyobj, *hash = has160_pyobj;
   PyObject *rc = 0;
   char *kwlist[] = { "G", "p", "u", "hash", "rng", 0 };
 
-  if (!PyArg_ParseTupleAndKeywords(arg, kw, "O!O!|OO!O!:new", kwlist,
+  if (!PyArg_ParseTupleAndKeywords(arg, kw, "O!O|O!O!O!:new", kwlist,
                                   group_pytype, &G,
-                                  ge_pytype, &p,
                                   &u,
+                                  ge_pytype, &p,
                                   gchash_pytype, &hash,
                                   grand_pytype, &rng) ||
-      (rc = dsa_setup(kcdsapriv_pytype, G, u, p, rng, hash)) == 0)
+      (rc = dsa_setup(kcdsapriv_pytype, G, u, p,
+                     rng, hash, kcdsa_calcpub)) == 0)
     goto end;
 end:
   return (rc);