First version of Threefish512-CTR with BLAKE3-MAC & a custom shamirs secret sharing port alongside C bridges with test vectors & Compilation instructions

crypto/shamirs_secret_sharing/py_bridge.c

@@ -0,0 +1,100 @@
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+#include <windows.h>
+#include <stdlib.h>
+#include <string.h>
+
+static PyObject *mod = NULL;
+static PyObject *combine_fn = NULL;
+static PyObject *split_fn = NULL;
+
+static void init_python()
+{
+    static int initialized = 0;
+    if (initialized) return;
+
+    Py_Initialize();
+
+    PyRun_SimpleString("import sys; sys.path.append('.')");
+
+    mod = PyImport_ImportModule("shamirs_secret_sharing");
+    if (!mod) {
+        PyErr_Print();
+        abort();
+    }
+
+    combine_fn = PyObject_GetAttrString(mod, "combine_wrapper");
+    split_fn   = PyObject_GetAttrString(mod, "split_wrapper");
+
+    if (!combine_fn || !split_fn) {
+        PyErr_Print();
+        abort();
+    }
+
+    initialized = 1;
+}
+
+__declspec(dllexport)
+char* combine_shares(const char** shares, int count)
+{
+    init_python();
+
+    PyObject* list = PyList_New(count);
+    for (int i = 0; i < count; i++) {
+        PyList_SetItem(list, i, PyUnicode_FromString(shares[i]));
+    }
+
+    PyObject* args = PyTuple_Pack(2, list, PyLong_FromLong(count));
+    PyObject* res = PyObject_CallObject(combine_fn, args);
+
+    Py_DECREF(list);
+    Py_DECREF(args);
+
+    if (!res) {
+        PyErr_Print();
+        return NULL;
+    }
+
+    const char* s = PyUnicode_AsUTF8(res);
+    char* out = _strdup(s);
+    Py_DECREF(res);
+    return out;
+}
+
+__declspec(dllexport)
+char* split_secret(const char* secret, int shares, int threshold)
+{
+    init_python();
+
+    PyObject* pystr = PyUnicode_FromString(secret);
+    PyObject* list = PyList_New(1);
+    PyList_SetItem(list, 0, pystr);
+
+    PyObject* args = PyTuple_Pack(4,
+        list,
+        PyLong_FromLong(1),
+        PyLong_FromLong(shares),
+        PyLong_FromLong(threshold)
+    );
+
+    PyObject* res = PyObject_CallObject(split_fn, args);
+
+    Py_DECREF(list);
+    Py_DECREF(args);
+
+    if (!res) {
+        PyErr_Print();
+        return NULL;
+    }
+
+    const char* s = PyUnicode_AsUTF8(res);
+    char* out = _strdup(s);
+    Py_DECREF(res);
+    return out;
+}
+
+__declspec(dllexport)
+void free_string(char* p)
+{
+    free(p);
+}