src/third_party/tlslite/tlslite/utils/win32prng.c

   1
   2 #include "Python.h"
   3 #define _WIN32_WINNT 0x0400       /* Needed for CryptoAPI on some systems */
   4 #include <windows.h>
   5
   6
   7 static PyObject* getRandomBytes(PyObject *self, PyObject *args)
   8 {
   9         int howMany;
  10         HCRYPTPROV hCryptProv;
  11         unsigned char* bytes = NULL;
  12         PyObject* returnVal = NULL;
  13
  14
  15         /* Read Arguments */
  16     if (!PyArg_ParseTuple(args, "i", &howMany))
  17         return(NULL);
  18
  19         /* Get Context */
  20         if(CryptAcquireContext(
  21            &hCryptProv,
  22            NULL,
  23            NULL,
  24            PROV_RSA_FULL,
  25            CRYPT_VERIFYCONTEXT) == 0)
  26                 return Py_BuildValue("s#", NULL, 0);
  27
  28
  29         /* Allocate bytes */
  30         bytes = malloc(howMany);
  31
  32
  33         /* Get random data */
  34         if(CryptGenRandom(
  35            hCryptProv,
  36            howMany,
  37            bytes) == 0)
  38                 returnVal = Py_BuildValue("s#", NULL, 0);
  39         else
  40                 returnVal = Py_BuildValue("s#", bytes, howMany);
  41
  42         free(bytes);
  43         CryptReleaseContext(hCryptProv, 0);
  44
  45         return returnVal;
  46 }
  47
  48
  49
  50 /* List of functions exported by this module */
  51
  52 static struct PyMethodDef win32prng_functions[] = {
  53     {"getRandomBytes", (PyCFunction)getRandomBytes, METH_VARARGS},
  54     {NULL,  NULL}        /* Sentinel */
  55 };
  56
  57
  58 /* Initialize this module. */
  59
  60 DL_EXPORT(void) initwin32prng(void)
  61 {
  62     Py_InitModule("win32prng", win32prng_functions);
  63 }