Random number generator in Python core

Modules/posixmodule.c

--- a/Modules/posixmodule.c	Fri Dec 30 21:26:08 2011 +0100
+++ b/Modules/posixmodule.c	Tue Jan 03 21:48:43 2012 +0100
@@ -9330,17 +9330,6 @@
 "urandom(n) -> str\n\n\
 Return n random bytes suitable for cryptographic use.");
 
-typedef BOOL (WINAPI *CRYPTACQUIRECONTEXTA)(HCRYPTPROV *phProv,\
-              LPCSTR pszContainer, LPCSTR pszProvider, DWORD dwProvType,\
-              DWORD dwFlags );
-typedef BOOL (WINAPI *CRYPTGENRANDOM)(HCRYPTPROV hProv, DWORD dwLen,\
-              BYTE *pbBuffer );
-
-static CRYPTGENRANDOM pCryptGenRandom = NULL;
-/* This handle is never explicitly released. Instead, the operating
-   system will release it when the process terminates. */
-static HCRYPTPROV hCryptProv = 0;
-
 static PyObject*
 win32_urandom(PyObject *self, PyObject *args)
 {
@@ -9350,50 +9339,15 @@
     /* Read arguments */
     if (! PyArg_ParseTuple(args, "i:urandom", &howMany))
         return NULL;
-    if (howMany < 0)
-        return PyErr_Format(PyExc_ValueError,
-                            "negative argument not allowed");
-
-    if (hCryptProv == 0) {
-        HINSTANCE hAdvAPI32 = NULL;
-        CRYPTACQUIRECONTEXTA pCryptAcquireContext = NULL;
-
-        /* Obtain handle to the DLL containing CryptoAPI
-           This should not fail         */
-        hAdvAPI32 = GetModuleHandle("advapi32.dll");
-        if(hAdvAPI32 == NULL)
-            return win32_error("GetModuleHandle", NULL);
-
-        /* Obtain pointers to the CryptoAPI functions
-           This will fail on some early versions of Win95 */
-        pCryptAcquireContext = (CRYPTACQUIRECONTEXTA)GetProcAddress(
-                                        hAdvAPI32,
-                                        "CryptAcquireContextA");
-        if (pCryptAcquireContext == NULL)
-            return PyErr_Format(PyExc_NotImplementedError,
-                                "CryptAcquireContextA not found");
-
-        pCryptGenRandom = (CRYPTGENRANDOM)GetProcAddress(
-                                        hAdvAPI32, "CryptGenRandom");
-        if (pCryptGenRandom == NULL)
-            return PyErr_Format(PyExc_NotImplementedError,
-                                "CryptGenRandom not found");
-
-        /* Acquire context */
-        if (! pCryptAcquireContext(&hCryptProv, NULL, NULL,
-                                   PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
-            return win32_error("CryptAcquireContext", NULL);
-    }
 
     /* Allocate bytes */
     result = PyBytes_FromStringAndSize(NULL, howMany);
     if (result != NULL) {
         /* Get random data */
         memset(PyBytes_AS_STRING(result), 0, howMany); /* zero seed */
-        if (! pCryptGenRandom(hCryptProv, howMany, (unsigned char*)
-                              PyBytes_AS_STRING(result))) {
+        if (PyOS_URandom(PyBytes_AS_STRING(result), howMany) == -1) {
             Py_DECREF(result);
-            return win32_error("CryptGenRandom", NULL);
+            return NULL;
         }
     }
     return result;