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/* tell python that PyArg_ParseTuple(t#) means Py_ssize_t, not int */
#define PY_SSIZE_T_CLEAN
#include <Python.h>
#if (PY_VERSION_HEX < 0x02050000)
typedef int Py_ssize_t;
#endif
/* This is required for compatibility with Python 2. */
#if PY_MAJOR_VERSION >= 3
#include <bytesobject.h>
#define y "y"
#else
#define PyBytes_FromStringAndSize PyString_FromStringAndSize
#define y "t"
#endif
int curve25519_donna(char *mypublic,
const char *secret, const char *basepoint);
static PyObject *
pycurve25519_makeprivate(PyObject *self, PyObject *args)
{
char *in1;
Py_ssize_t in1len;
if (!PyArg_ParseTuple(args, y"#:clamp", &in1, &in1len))
return NULL;
if (in1len != 32) {
PyErr_SetString(PyExc_ValueError, "input must be 32-byte string");
return NULL;
}
in1[0] &= 248;
in1[31] &= 127;
in1[31] |= 64;
return PyBytes_FromStringAndSize((char *)in1, 32);
}
static PyObject *
pycurve25519_makepublic(PyObject *self, PyObject *args)
{
const char *private;
char mypublic[32];
char basepoint[32] = {9};
Py_ssize_t privatelen;
if (!PyArg_ParseTuple(args, y"#:makepublic", &private, &privatelen))
return NULL;
if (privatelen != 32) {
PyErr_SetString(PyExc_ValueError, "input must be 32-byte string");
return NULL;
}
curve25519_donna(mypublic, private, basepoint);
return PyBytes_FromStringAndSize((char *)mypublic, 32);
}
static PyObject *
pycurve25519_makeshared(PyObject *self, PyObject *args)
{
const char *myprivate, *theirpublic;
char shared_key[32];
Py_ssize_t myprivatelen, theirpubliclen;
if (!PyArg_ParseTuple(args, y"#"y"#:generate",
&myprivate, &myprivatelen, &theirpublic, &theirpubliclen))
return NULL;
if (myprivatelen != 32) {
PyErr_SetString(PyExc_ValueError, "input must be 32-byte string");
return NULL;
}
if (theirpubliclen != 32) {
PyErr_SetString(PyExc_ValueError, "input must be 32-byte string");
return NULL;
}
curve25519_donna(shared_key, myprivate, theirpublic);
return PyBytes_FromStringAndSize((char *)shared_key, 32);
}
static PyMethodDef
curve25519_functions[] = {
{"make_private", pycurve25519_makeprivate, METH_VARARGS, "data->private"},
{"make_public", pycurve25519_makepublic, METH_VARARGS, "private->public"},
{"make_shared", pycurve25519_makeshared, METH_VARARGS, "private+public->shared"},
{NULL, NULL, 0, NULL},
};
#if PY_MAJOR_VERSION >= 3
static struct PyModuleDef
curve25519_module = {
PyModuleDef_HEAD_INIT,
"_curve25519",
NULL,
NULL,
curve25519_functions,
};
PyObject *
PyInit__curve25519(void)
{
return PyModule_Create(&curve25519_module);
}
#else
PyMODINIT_FUNC
init_curve25519(void)
{
(void)Py_InitModule("_curve25519", curve25519_functions);
}
#endif
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