/*

 * Copyright 1995-2019 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include "internal/cryptlib.h"

#include <openssl/rand.h>

#include "rand_local.h"

#include "crypto/rand.h"

#if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)

# ifndef OPENSSL_RAND_SEED_OS

#  error "Unsupported seeding method configured; must be os"

# endif

# include <windows.h>

/* On Windows Vista or higher use BCrypt instead of the legacy CryptoAPI */

# if defined(_MSC_VER) && _MSC_VER > 1500 /* 1500 = Visual Studio 2008 */ \

     && defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0600

#  define USE_BCRYPTGENRANDOM

# endif

# ifdef USE_BCRYPTGENRANDOM

#  include <bcrypt.h>

#  pragma comment(lib, "bcrypt.lib")

#  ifndef STATUS_SUCCESS

#   define STATUS_SUCCESS ((NTSTATUS)0x00000000L)

#  endif

# else

#  include <wincrypt.h>

/*

 * Intel hardware RNG CSP -- available from

 * http://developer.intel.com/design/security/rng/redist_license.htm

 */

#  define PROV_INTEL_SEC 22

#  define INTEL_DEF_PROV L"Intel Hardware Cryptographic Service Provider"

# endif

size_t rand_pool_acquire_entropy(RAND_POOL *pool)

{

# ifndef USE_BCRYPTGENRANDOM

    HCRYPTPROV hProvider;

# endif

    unsigned char *buffer;

    size_t bytes_needed;

    size_t entropy_available = 0;

# ifdef OPENSSL_RAND_SEED_RDTSC

    entropy_available = rand_acquire_entropy_from_tsc(pool);

    if (entropy_available > 0)

        return entropy_available;

# endif

# ifdef OPENSSL_RAND_SEED_RDCPU

    entropy_available = rand_acquire_entropy_from_cpu(pool);

    if (entropy_available > 0)

        return entropy_available;

# endif

# ifdef USE_BCRYPTGENRANDOM

    bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);

    buffer = rand_pool_add_begin(pool, bytes_needed);

    if (buffer != NULL) {

        size_t bytes = 0;

        if (BCryptGenRandom(NULL, buffer, bytes_needed,

                            BCRYPT_USE_SYSTEM_PREFERRED_RNG) == STATUS_SUCCESS)

            bytes = bytes_needed;

        rand_pool_add_end(pool, bytes, 8 * bytes);

        entropy_available = rand_pool_entropy_available(pool);

    }

    if (entropy_available > 0)

        return entropy_available;

# else

    bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);

    buffer = rand_pool_add_begin(pool, bytes_needed);

    if (buffer != NULL) {

        size_t bytes = 0;

        /* poll the CryptoAPI PRNG */

        if (CryptAcquireContextW(&hProvider, NULL, NULL, PROV_RSA_FULL,

                                 CRYPT_VERIFYCONTEXT | CRYPT_SILENT) != 0) {

            if (CryptGenRandom(hProvider, bytes_needed, buffer) != 0)

                bytes = bytes_needed;

            CryptReleaseContext(hProvider, 0);

        }

        rand_pool_add_end(pool, bytes, 8 * bytes);

        entropy_available = rand_pool_entropy_available(pool);

    }

    if (entropy_available > 0)

        return entropy_available;

    bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);

    buffer = rand_pool_add_begin(pool, bytes_needed);

    if (buffer != NULL) {

        size_t bytes = 0;

        /* poll the Pentium PRG with CryptoAPI */

        if (CryptAcquireContextW(&hProvider, NULL,

                                 INTEL_DEF_PROV, PROV_INTEL_SEC,

                                 CRYPT_VERIFYCONTEXT | CRYPT_SILENT) != 0) {

            if (CryptGenRandom(hProvider, bytes_needed, buffer) != 0)

                bytes = bytes_needed;

            CryptReleaseContext(hProvider, 0);

        }

        rand_pool_add_end(pool, bytes, 8 * bytes);

        entropy_available = rand_pool_entropy_available(pool);

    }

    if (entropy_available > 0)

        return entropy_available;

# endif

    return rand_pool_entropy_available(pool);

}

int rand_pool_add_nonce_data(RAND_POOL *pool)

{

    struct {

        DWORD pid;

        DWORD tid;

        FILETIME time;

    } data = { 0 };

    /*

     * Add process id, thread id, and a high resolution timestamp to

     * ensure that the nonce is unique with high probability for

     * different process instances.

     */

    data.pid = GetCurrentProcessId();

    data.tid = GetCurrentThreadId();

    GetSystemTimeAsFileTime(&data.time);

    return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);

}

int rand_pool_add_additional_data(RAND_POOL *pool)

{

    struct {

        DWORD tid;

        LARGE_INTEGER time;

    } data = { 0 };

    /*

     * Add some noise from the thread id and a high resolution timer.

     * The thread id adds a little randomness if the drbg is accessed

     * concurrently (which is the case for the <master> drbg).

     */

    data.tid = GetCurrentThreadId();

    QueryPerformanceCounter(&data.time);

    return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);

}

# if OPENSSL_API_COMPAT < 0x10100000L

int RAND_event(UINT iMsg, WPARAM wParam, LPARAM lParam)

{

    RAND_poll();

    return RAND_status();

}

void RAND_screen(void)

{

    RAND_poll();

}

# endif

int rand_pool_init(void)

{

    return 1;

}

void rand_pool_cleanup(void)

{

}

void rand_pool_keep_random_devices_open(int keep)

{

}

#endif