AppPkg/Applications/Python/Python-2.7.10: Initial Checkin part 5/5.

[mirror_edk2.git] / AppPkg / Applications / Python / Python-2.7.10 / PyMod-2.7.10 / Python / random.c

#include "Python.h"\r
#ifdef MS_WINDOWS\r
#include <windows.h>\r
#else\r
#include <fcntl.h>\r
#endif\r
\r
#ifdef Py_DEBUG\r
int _Py_HashSecret_Initialized = 0;\r
#else\r
static int _Py_HashSecret_Initialized = 0;\r
#endif\r
\r
#ifdef MS_WINDOWS\r
typedef BOOL (WINAPI *CRYPTACQUIRECONTEXTA)(HCRYPTPROV *phProv,\\r
              LPCSTR pszContainer, LPCSTR pszProvider, DWORD dwProvType,\\r
              DWORD dwFlags );\r
typedef BOOL (WINAPI *CRYPTGENRANDOM)(HCRYPTPROV hProv, DWORD dwLen,\\r
              BYTE *pbBuffer );\r
\r
static CRYPTGENRANDOM pCryptGenRandom = NULL;\r
/* This handle is never explicitly released. Instead, the operating\r
   system will release it when the process terminates. */\r
static HCRYPTPROV hCryptProv = 0;\r
\r
static int\r
win32_urandom_init(int raise)\r
{\r
    HINSTANCE hAdvAPI32 = NULL;\r
    CRYPTACQUIRECONTEXTA pCryptAcquireContext = NULL;\r
\r
    /* Obtain handle to the DLL containing CryptoAPI. This should not fail. */\r
    hAdvAPI32 = GetModuleHandle("advapi32.dll");\r
    if(hAdvAPI32 == NULL)\r
        goto error;\r
\r
    /* Obtain pointers to the CryptoAPI functions. This will fail on some early\r
       versions of Win95. */\r
    pCryptAcquireContext = (CRYPTACQUIRECONTEXTA)GetProcAddress(\r
                               hAdvAPI32, "CryptAcquireContextA");\r
    if (pCryptAcquireContext == NULL)\r
        goto error;\r
\r
    pCryptGenRandom = (CRYPTGENRANDOM)GetProcAddress(hAdvAPI32,\r
                                                     "CryptGenRandom");\r
    if (pCryptGenRandom == NULL)\r
        goto error;\r
\r
    /* Acquire context */\r
    if (! pCryptAcquireContext(&hCryptProv, NULL, NULL,\r
                               PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))\r
        goto error;\r
\r
    return 0;\r
\r
error:\r
    if (raise)\r
        PyErr_SetFromWindowsErr(0);\r
    else\r
        Py_FatalError("Failed to initialize Windows random API (CryptoGen)");\r
    return -1;\r
}\r
\r
/* Fill buffer with size pseudo-random bytes generated by the Windows CryptoGen\r
   API. Return 0 on success, or -1 on error. */\r
static int\r
win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise)\r
{\r
    Py_ssize_t chunk;\r
\r
    if (hCryptProv == 0)\r
    {\r
        if (win32_urandom_init(raise) == -1)\r
            return -1;\r
    }\r
\r
    while (size > 0)\r
    {\r
        chunk = size > INT_MAX ? INT_MAX : size;\r
        if (!pCryptGenRandom(hCryptProv, chunk, buffer))\r
        {\r
            /* CryptGenRandom() failed */\r
            if (raise)\r
                PyErr_SetFromWindowsErr(0);\r
            else\r
                Py_FatalError("Failed to initialized the randomized hash "\r
                        "secret using CryptoGen)");\r
            return -1;\r
        }\r
        buffer += chunk;\r
        size -= chunk;\r
    }\r
    return 0;\r
}\r
\r
#elif HAVE_GETENTROPY\r
/* Fill buffer with size pseudo-random bytes generated by getentropy().\r
   Return 0 on success, or raise an exception and return -1 on error.\r
   If fatal is nonzero, call Py_FatalError() instead of raising an exception\r
   on error. */\r
static int\r
py_getentropy(unsigned char *buffer, Py_ssize_t size, int fatal)\r
{\r
    while (size > 0) {\r
        Py_ssize_t len = size < 256 ? size : 256;\r
        int res;\r
\r
        if (!fatal) {\r
            Py_BEGIN_ALLOW_THREADS\r
            res = getentropy(buffer, len);\r
            Py_END_ALLOW_THREADS\r
\r
            if (res < 0) {\r
                PyErr_SetFromErrno(PyExc_OSError);\r
                return -1;\r
            }\r
        }\r
        else {\r
            res = getentropy(buffer, len);\r
            if (res < 0)\r
                Py_FatalError("getentropy() failed");\r
        }\r
\r
        buffer += len;\r
        size -= len;\r
    }\r
    return 0;\r
}\r
#endif\r
\r
#ifdef __VMS\r
/* Use openssl random routine */\r
#include <openssl/rand.h>\r
static int\r
vms_urandom(unsigned char *buffer, Py_ssize_t size, int raise)\r
{\r
    if (RAND_pseudo_bytes(buffer, size) < 0) {\r
        if (raise) {\r
            PyErr_Format(PyExc_ValueError,\r
                         "RAND_pseudo_bytes");\r
        } else {\r
            Py_FatalError("Failed to initialize the randomized hash "\r
                          "secret using RAND_pseudo_bytes");\r
        }\r
        return -1;\r
    }\r
    return 0;\r
}\r
#endif /* __VMS */\r
\r
\r
#if !defined(MS_WINDOWS) && !defined(__VMS)\r
\r
static struct {\r
    int fd;\r
    dev_t st_dev;\r
    ino_t st_ino;\r
} urandom_cache = { -1 };\r
\r
/* Read size bytes from /dev/urandom into buffer.\r
   Call Py_FatalError() on error. */\r
static void\r
dev_urandom_noraise(unsigned char *buffer, Py_ssize_t size)\r
{\r
    int fd;\r
    Py_ssize_t n;\r
\r
    assert (0 < size);\r
\r
    fd = open("/dev/urandom", O_RDONLY);\r
    if (fd < 0)\r
        Py_FatalError("Failed to open /dev/urandom");\r
\r
    while (0 < size)\r
    {\r
        do {\r
            n = read(fd, buffer, (size_t)size);\r
        } while (n < 0 && errno == EINTR);\r
        if (n <= 0)\r
        {\r
            /* stop on error or if read(size) returned 0 */\r
            Py_FatalError("Failed to read bytes from /dev/urandom");\r
            break;\r
        }\r
        buffer += n;\r
        size -= (Py_ssize_t)n;\r
    }\r
    close(fd);\r
}\r
\r
/* Read size bytes from /dev/urandom into buffer.\r
   Return 0 on success, raise an exception and return -1 on error. */\r
static int\r
dev_urandom_python(char *buffer, Py_ssize_t size)\r
{\r
    int fd;\r
    Py_ssize_t n;\r
    struct stat st;\r
    int attr;\r
\r
    if (size <= 0)\r
        return 0;\r
\r
    if (urandom_cache.fd >= 0) {\r
        /* Does the fd point to the same thing as before? (issue #21207) */\r
        if (fstat(urandom_cache.fd, &st)\r
            || st.st_dev != urandom_cache.st_dev\r
            || st.st_ino != urandom_cache.st_ino) {\r
            /* Something changed: forget the cached fd (but don't close it,\r
               since it probably points to something important for some\r
               third-party code). */\r
            urandom_cache.fd = -1;\r
        }\r
    }\r
    if (urandom_cache.fd >= 0)\r
        fd = urandom_cache.fd;\r
    else {\r
        Py_BEGIN_ALLOW_THREADS\r
        fd = open("/dev/urandom", O_RDONLY);\r
        Py_END_ALLOW_THREADS\r
        if (fd < 0)\r
        {\r
            if (errno == ENOENT || errno == ENXIO ||\r
                errno == ENODEV || errno == EACCES)\r
                PyErr_SetString(PyExc_NotImplementedError,\r
                                "/dev/urandom (or equivalent) not found");\r
            else\r
                PyErr_SetFromErrno(PyExc_OSError);\r
            return -1;\r
        }\r
\r
        /* try to make the file descriptor non-inheritable, ignore errors */\r
        attr = fcntl(fd, F_GETFD);\r
        if (attr >= 0) {\r
            attr |= FD_CLOEXEC;\r
            (void)fcntl(fd, F_SETFD, attr);\r
        }\r
\r
        if (urandom_cache.fd >= 0) {\r
            /* urandom_fd was initialized by another thread while we were\r
               not holding the GIL, keep it. */\r
            close(fd);\r
            fd = urandom_cache.fd;\r
        }\r
        else {\r
            if (fstat(fd, &st)) {\r
                PyErr_SetFromErrno(PyExc_OSError);\r
                close(fd);\r
                return -1;\r
            }\r
            else {\r
                urandom_cache.fd = fd;\r
                urandom_cache.st_dev = st.st_dev;\r
                urandom_cache.st_ino = st.st_ino;\r
            }\r
        }\r
    }\r
\r
    Py_BEGIN_ALLOW_THREADS\r
    do {\r
        do {\r
            n = read(fd, buffer, (size_t)size);\r
        } while (n < 0 && errno == EINTR);\r
        if (n <= 0)\r
            break;\r
        buffer += n;\r
        size -= (Py_ssize_t)n;\r
    } while (0 < size);\r
    Py_END_ALLOW_THREADS\r
\r
    if (n <= 0)\r
    {\r
        /* stop on error or if read(size) returned 0 */\r
        if (n < 0)\r
            PyErr_SetFromErrno(PyExc_OSError);\r
        else\r
            PyErr_Format(PyExc_RuntimeError,\r
                         "Failed to read %zi bytes from /dev/urandom",\r
                         size);\r
        return -1;\r
    }\r
    return 0;\r
}\r
\r
static void\r
dev_urandom_close(void)\r
{\r
    if (urandom_cache.fd >= 0) {\r
        close(urandom_cache.fd);\r
        urandom_cache.fd = -1;\r
    }\r
}\r
\r
\r
#endif /* !defined(MS_WINDOWS) && !defined(__VMS) */\r
\r
/* Fill buffer with pseudo-random bytes generated by a linear congruent\r
   generator (LCG):\r
\r
       x(n+1) = (x(n) * 214013 + 2531011) % 2^32\r
\r
   Use bits 23..16 of x(n) to generate a byte. */\r
static void\r
lcg_urandom(unsigned int x0, unsigned char *buffer, size_t size)\r
{\r
    size_t index;\r
    unsigned int x;\r
\r
    x = x0;\r
    for (index=0; index < size; index++) {\r
        x *= 214013;\r
        x += 2531011;\r
        /* modulo 2 ^ (8 * sizeof(int)) */\r
        buffer[index] = (x >> 16) & 0xff;\r
    }\r
}\r
\r
/* Fill buffer with size pseudo-random bytes from the operating system random\r
   number generator (RNG). It is suitable for most cryptographic purposes\r
   except long living private keys for asymmetric encryption.\r
\r
   Return 0 on success, raise an exception and return -1 on error. */\r
int\r
_PyOS_URandom(void *buffer, Py_ssize_t size)\r
{\r
    if (size < 0) {\r
        PyErr_Format(PyExc_ValueError,\r
                     "negative argument not allowed");\r
        return -1;\r
    }\r
    if (size == 0)\r
        return 0;\r
\r
#ifdef MS_WINDOWS\r
    return win32_urandom((unsigned char *)buffer, size, 1);\r
#elif HAVE_GETENTROPY\r
    return py_getentropy(buffer, size, 0);\r
#else\r
# ifdef __VMS\r
    return vms_urandom((unsigned char *)buffer, size, 1);\r
# else\r
    return dev_urandom_python((char*)buffer, size);\r
# endif\r
#endif\r
}\r
\r
void\r
_PyRandom_Init(void)\r
{\r
    char *env;\r
    void *secret = &_Py_HashSecret;\r
    Py_ssize_t secret_size = sizeof(_Py_HashSecret_t);\r
\r
    if (_Py_HashSecret_Initialized)\r
        return;\r
    _Py_HashSecret_Initialized = 1;\r
\r
    /*\r
      By default, hash randomization is disabled, and only\r
      enabled if PYTHONHASHSEED is set to non-empty or if\r
      "-R" is provided at the command line:\r
    */\r
    if (!Py_HashRandomizationFlag) {\r
        /* Disable the randomized hash: */\r
        memset(secret, 0, secret_size);\r
        return;\r
    }\r
\r
    /*\r
      Hash randomization is enabled.  Generate a per-process secret,\r
      using PYTHONHASHSEED if provided.\r
    */\r
\r
    env = Py_GETENV("PYTHONHASHSEED");\r
    if (env && *env != '\0' && strcmp(env, "random") != 0) {\r
        char *endptr = env;\r
        unsigned long seed;\r
        seed = strtoul(env, &endptr, 10);\r
        if (*endptr != '\0'\r
            || seed > 4294967295UL\r
            || (errno == ERANGE && seed == ULONG_MAX))\r
        {\r
            Py_FatalError("PYTHONHASHSEED must be \"random\" or an integer "\r
                          "in range [0; 4294967295]");\r
        }\r
        if (seed == 0) {\r
            /* disable the randomized hash */\r
            memset(secret, 0, secret_size);\r
        }\r
        else {\r
            lcg_urandom(seed, (unsigned char*)secret, secret_size);\r
        }\r
    }\r
    else {\r
#ifdef MS_WINDOWS\r
        (void)win32_urandom((unsigned char *)secret, secret_size, 0);\r
#elif __VMS\r
        vms_urandom((unsigned char *)secret, secret_size, 0);\r
#elif HAVE_GETENTROPY\r
        (void)py_getentropy(secret, secret_size, 1);\r
#else\r
        dev_urandom_noraise(secret, secret_size);\r
#endif\r
    }\r
}\r
\r
void\r
_PyRandom_Fini(void)\r
{\r
#ifdef MS_WINDOWS\r
    if (hCryptProv) {\r
        CryptReleaseContext(hCryptProv, 0);\r
        hCryptProv = 0;\r
    }\r
#elif HAVE_GETENTROPY\r
    /* nothing to clean */\r
#else\r
    dev_urandom_close();\r
#endif\r
}\r