#include "Python.h"
#ifdef MS_WINDOWS
#include 
#else
#include 
#endif

#ifdef Py_DEBUG
int _Py_HashSecret_Initialized = 0;
#else
static int _Py_HashSecret_Initialized = 0;
#endif

#ifdef MS_WINDOWS
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 int
win32_urandom_init(int raise)
{
    HINSTANCE hAdvAPI32 = NULL;
    CRYPTACQUIRECONTEXTA pCryptAcquireContext = NULL;

    /* Obtain handle to the DLL containing CryptoAPI. This should not fail. */
    hAdvAPI32 = GetModuleHandle("advapi32.dll");
    if(hAdvAPI32 == NULL)
        goto error;

    /* Obtain pointers to the CryptoAPI functions. This will fail on some early
       versions of Win95. */
    pCryptAcquireContext = (CRYPTACQUIRECONTEXTA)GetProcAddress(
                               hAdvAPI32, "CryptAcquireContextA");
    if (pCryptAcquireContext == NULL)
        goto error;

    pCryptGenRandom = (CRYPTGENRANDOM)GetProcAddress(hAdvAPI32,
                                                     "CryptGenRandom");
    if (pCryptGenRandom == NULL)
        goto error;

    /* Acquire context */
    if (! pCryptAcquireContext(&hCryptProv, NULL, NULL,
                               PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
        goto error;

    return 0;

error:
    if (raise)
        PyErr_SetFromWindowsErr(0);
    else
        Py_FatalError("Failed to initialize Windows random API (CryptoGen)");
    return -1;
}

/* Fill buffer with size pseudo-random bytes generated by the Windows CryptoGen
   API. Return 0 on success, or -1 on error. */
static int
win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
{
    Py_ssize_t chunk;

    if (hCryptProv == 0)
    {
        if (win32_urandom_init(raise) == -1)
            return -1;
    }

    while (size > 0)
    {
        chunk = size > INT_MAX ? INT_MAX : size;
        if (!pCryptGenRandom(hCryptProv, chunk, buffer))
        {
            /* CryptGenRandom() failed */
            if (raise)
                PyErr_SetFromWindowsErr(0);
            else
                Py_FatalError("Failed to initialized the randomized hash "
                        "secret using CryptoGen)");
            return -1;
        }
        buffer += chunk;
        size -= chunk;
    }
    return 0;
}
#endif /* MS_WINDOWS */


#ifdef __VMS
/* Use openssl random routine */
#include 
static int
vms_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
{
    if (RAND_pseudo_bytes(buffer, size) < 0) {
        if (raise) {
            PyErr_Format(PyExc_ValueError,
                         "RAND_pseudo_bytes");
        } else {
            Py_FatalError("Failed to initialize the randomized hash "
                          "secret using RAND_pseudo_bytes");
        }
        return -1;
    }
    return 0;
}
#endif /* __VMS */


#if !defined(MS_WINDOWS) && !defined(__VMS)

/* Read size bytes from /dev/urandom into buffer.
   Call Py_FatalError() on error. */
static void
dev_urandom_noraise(char *buffer, Py_ssize_t size)
{
    int fd;
    Py_ssize_t n;

    assert (0 < size);

    fd = open("/dev/urandom", O_RDONLY);
    if (fd < 0)
        Py_FatalError("Failed to open /dev/urandom");

    while (0 < size)
    {
        do {
            n = read(fd, buffer, (size_t)size);
        } while (n < 0 && errno == EINTR);
        if (n