source: trunk/sys/libcrypto/others/rand_win.c @ 17

/* crypto/rand/rand_win.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */
/* ====================================================================
 * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include "cryptlib.h"
#include <openssl/rand.h>
#include "rand_lcl.h"

#if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
#include <windows.h>
#ifndef _WIN32_WINNT
# define _WIN32_WINNT 0x0400
#endif
#include <wincrypt.h>
#include <tlhelp32.h>

/* Limit the time spent walking through the heap, processes, threads and modules to
   a maximum of 1000 miliseconds each, unless CryptoGenRandom failed */
#define MAXDELAY 1000

/* 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"

static void readtimer(void);
static void readscreen(void);

/* It appears like CURSORINFO, PCURSORINFO and LPCURSORINFO are only defined
   when WINVER is 0x0500 and up, which currently only happens on Win2000.
   Unfortunately, those are typedefs, so they're a little bit difficult to
   detect properly.  On the other hand, the macro CURSOR_SHOWING is defined
   within the same conditional, so it can be use to detect the absence of said
   typedefs. */

#ifndef CURSOR_SHOWING
/*
 * Information about the global cursor.
 */
typedef struct tagCURSORINFO
{
    DWORD   cbSize;
    DWORD   flags;
    HCURSOR hCursor;
    POINT   ptScreenPos;
} CURSORINFO, *PCURSORINFO, *LPCURSORINFO;

#define CURSOR_SHOWING     0x00000001
#endif /* CURSOR_SHOWING */

#if !defined(OPENSSL_SYS_WINCE)
typedef BOOL (WINAPI *CRYPTACQUIRECONTEXTW)(HCRYPTPROV *, LPCWSTR, LPCWSTR,
                                    DWORD, DWORD);
typedef BOOL (WINAPI *CRYPTGENRANDOM)(HCRYPTPROV, DWORD, BYTE *);
typedef BOOL (WINAPI *CRYPTRELEASECONTEXT)(HCRYPTPROV, DWORD);

typedef HWND (WINAPI *GETFOREGROUNDWINDOW)(VOID);
typedef BOOL (WINAPI *GETCURSORINFO)(PCURSORINFO);
typedef DWORD (WINAPI *GETQUEUESTATUS)(UINT);

typedef HANDLE (WINAPI *CREATETOOLHELP32SNAPSHOT)(DWORD, DWORD);
typedef BOOL (WINAPI *CLOSETOOLHELP32SNAPSHOT)(HANDLE);
typedef BOOL (WINAPI *HEAP32FIRST)(LPHEAPENTRY32, DWORD, size_t);
typedef BOOL (WINAPI *HEAP32NEXT)(LPHEAPENTRY32);
typedef BOOL (WINAPI *HEAP32LIST)(HANDLE, LPHEAPLIST32);
typedef BOOL (WINAPI *PROCESS32)(HANDLE, LPPROCESSENTRY32);
typedef BOOL (WINAPI *THREAD32)(HANDLE, LPTHREADENTRY32);
typedef BOOL (WINAPI *MODULE32)(HANDLE, LPMODULEENTRY32);

#include <lmcons.h>
#include <lmstats.h>
#if 1 /* The NET API is Unicode only.  It requires the use of the UNICODE
       * macro.  When UNICODE is defined LPTSTR becomes LPWSTR.  LMSTR was
       * was added to the Platform SDK to allow the NET API to be used in
       * non-Unicode applications provided that Unicode strings were still
       * used for input.  LMSTR is defined as LPWSTR.
       */
typedef NET_API_STATUS (NET_API_FUNCTION * NETSTATGET)
        (LPWSTR, LPWSTR, DWORD, DWORD, LPBYTE*);
typedef NET_API_STATUS (NET_API_FUNCTION * NETFREE)(LPBYTE);
#endif /* 1 */
#endif /* !OPENSSL_SYS_WINCE */

int RAND_poll(void)
{
        MEMORYSTATUS m;
        HCRYPTPROV hProvider = 0;
        DWORD w;
        int good = 0;

        /* Determine the OS version we are on so we can turn off things 
         * that do not work properly.
         */
        OSVERSIONINFO osverinfo ;
        osverinfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFO) ;
        GetVersionEx( &osverinfo ) ;

#if defined(OPENSSL_SYS_WINCE)
# if defined(_WIN32_WCE) && _WIN32_WCE>=300
/* Even though MSDN says _WIN32_WCE>=210, it doesn't seem to be available
 * in commonly available implementations prior 300... */
        {
        BYTE buf[64];
        /* poll the CryptoAPI PRNG */
        /* The CryptoAPI returns sizeof(buf) bytes of randomness */
        if (CryptAcquireContextW(&hProvider, NULL, NULL, PROV_RSA_FULL,
                                CRYPT_VERIFYCONTEXT))
                {
                if (CryptGenRandom(hProvider, sizeof(buf), buf))
                        RAND_add(buf, sizeof(buf), sizeof(buf));
                CryptReleaseContext(hProvider, 0); 
                }
        }
# endif
#else   /* OPENSSL_SYS_WINCE */
        /*
         * None of below libraries are present on Windows CE, which is
         * why we #ifndef the whole section. This also excuses us from
         * handling the GetProcAddress issue. The trouble is that in
         * real Win32 API GetProcAddress is available in ANSI flavor
         * only. In WinCE on the other hand GetProcAddress is a macro
         * most commonly defined as GetProcAddressW, which accepts
         * Unicode argument. If we were to call GetProcAddress under
         * WinCE, I'd recommend to either redefine GetProcAddress as
         * GetProcAddressA (there seem to be one in common CE spec) or
         * implement own shim routine, which would accept ANSI argument
         * and expand it to Unicode.
         */
        {
        /* load functions dynamically - not available on all systems */
        HMODULE advapi = LoadLibrary(TEXT("ADVAPI32.DLL"));
        HMODULE kernel = LoadLibrary(TEXT("KERNEL32.DLL"));
        HMODULE user = NULL;
        HMODULE netapi = LoadLibrary(TEXT("NETAPI32.DLL"));
        CRYPTACQUIRECONTEXTW acquire = NULL;
        CRYPTGENRANDOM gen = NULL;
        CRYPTRELEASECONTEXT release = NULL;
        NETSTATGET netstatget = NULL;
        NETFREE netfree = NULL;
        BYTE buf[64];

        if (netapi)
                {
                netstatget = (NETSTATGET) GetProcAddress(netapi,"NetStatisticsGet");
                netfree = (NETFREE) GetProcAddress(netapi,"NetApiBufferFree");
                }

        if (netstatget && netfree)
                {
                LPBYTE outbuf;
                /* NetStatisticsGet() is a Unicode only function
                 * STAT_WORKSTATION_0 contains 45 fields and STAT_SERVER_0
                 * contains 17 fields.  We treat each field as a source of
                 * one byte of entropy.
                 */

                if (netstatget(NULL, L"LanmanWorkstation", 0, 0, &outbuf) == 0)
                        {
                        RAND_add(outbuf, sizeof(STAT_WORKSTATION_0), 45);
                        netfree(outbuf);
                        }
                if (netstatget(NULL, L"LanmanServer", 0, 0, &outbuf) == 0)
                        {
                        RAND_add(outbuf, sizeof(STAT_SERVER_0), 17);
                        netfree(outbuf);
                        }
                }

        if (netapi)
                FreeLibrary(netapi);

        /* It appears like this can cause an exception deep within ADVAPI32.DLL
         * at random times on Windows 2000.  Reported by Jeffrey Altman.  
         * Only use it on NT.
         */
        /* Wolfgang Marczy <WMarczy@topcall.co.at> reports that
         * the RegQueryValueEx call below can hang on NT4.0 (SP6).
         * So we don't use this at all for now. */
#if 0
        if ( osverinfo.dwPlatformId == VER_PLATFORM_WIN32_NT &&
                osverinfo.dwMajorVersion < 5)
                {
                /* Read Performance Statistics from NT/2000 registry
                 * The size of the performance data can vary from call
                 * to call so we must guess the size of the buffer to use
                 * and increase its size if we get an ERROR_MORE_DATA
                 * return instead of ERROR_SUCCESS.
                 */
                LONG   rc=ERROR_MORE_DATA;
                char * buf=NULL;
                DWORD bufsz=0;
                DWORD length;

                while (rc == ERROR_MORE_DATA)
                        {
                        buf = realloc(buf,bufsz+8192);
                        if (!buf)
                                break;
                        bufsz += 8192;

                        length = bufsz;
                        rc = RegQueryValueEx(HKEY_PERFORMANCE_DATA, TEXT("Global"),
                                NULL, NULL, buf, &length);
                        }
                if (rc == ERROR_SUCCESS)
                        {
                        /* For entropy count assume only least significant
                         * byte of each DWORD is random.
                         */
                        RAND_add(&length, sizeof(length), 0);
                        RAND_add(buf, length, length / 4.0);

                        /* Close the Registry Key to allow Windows to cleanup/close
                         * the open handle
                         * Note: The 'HKEY_PERFORMANCE_DATA' key is implicitly opened
                         *       when the RegQueryValueEx above is done.  However, if
                         *       it is not explicitly closed, it can cause disk
                         *       partition manipulation problems.
                         */
                        RegCloseKey(HKEY_PERFORMANCE_DATA);
                        }
                if (buf)
                        free(buf);
                }
#endif

        if (advapi)
                {
                /*
                 * If it's available, then it's available in both ANSI
                 * and UNICODE flavors even in Win9x, documentation says.
                 * We favor Unicode...
                 */
                acquire = (CRYPTACQUIRECONTEXTW) GetProcAddress(advapi,
                        "CryptAcquireContextW");
                gen = (CRYPTGENRANDOM) GetProcAddress(advapi,
                        "CryptGenRandom");
                release = (CRYPTRELEASECONTEXT) GetProcAddress(advapi,
                        "CryptReleaseContext");
                }

        if (acquire && gen && release)
                {
                /* poll the CryptoAPI PRNG */
                /* The CryptoAPI returns sizeof(buf) bytes of randomness */
                if (acquire(&hProvider, NULL, NULL, PROV_RSA_FULL,
                        CRYPT_VERIFYCONTEXT))
                        {
                        if (gen(hProvider, sizeof(buf), buf) != 0)
                                {
                                RAND_add(buf, sizeof(buf), 0);
                                good = 1;
#if 0
                                printf("randomness from PROV_RSA_FULL\n");
#endif
                                }
                        release(hProvider, 0); 
                        }
                
                /* poll the Pentium PRG with CryptoAPI */
                if (acquire(&hProvider, 0, INTEL_DEF_PROV, PROV_INTEL_SEC, 0))
                        {
                        if (gen(hProvider, sizeof(buf), buf) != 0)
                                {
                                RAND_add(buf, sizeof(buf), sizeof(buf));
                                good = 1;
#if 0
                                printf("randomness from PROV_INTEL_SEC\n");
#endif
                                }
                        release(hProvider, 0);
                        }
                }

        if (advapi)
                FreeLibrary(advapi);

        if ((osverinfo.dwPlatformId != VER_PLATFORM_WIN32_NT ||
             !OPENSSL_isservice()) &&
            (user = LoadLibrary(TEXT("USER32.DLL"))))
                {
                GETCURSORINFO cursor;
                GETFOREGROUNDWINDOW win;
                GETQUEUESTATUS queue;

                win = (GETFOREGROUNDWINDOW) GetProcAddress(user, "GetForegroundWindow");
                cursor = (GETCURSORINFO) GetProcAddress(user, "GetCursorInfo");
                queue = (GETQUEUESTATUS) GetProcAddress(user, "GetQueueStatus");

                if (win)
                        {
                        /* window handle */
                        HWND h = win();
                        RAND_add(&h, sizeof(h), 0);
                        }
                if (cursor)
                        {
                        /* unfortunately, its not safe to call GetCursorInfo()
                         * on NT4 even though it exists in SP3 (or SP6) and
                         * higher.
                         */
                        if ( osverinfo.dwPlatformId == VER_PLATFORM_WIN32_NT &&
                                osverinfo.dwMajorVersion < 5)
                                cursor = 0;
                        }
                if (cursor)
                        {
                        /* cursor position */
                        /* assume 2 bytes of entropy */
                        CURSORINFO ci;
                        ci.cbSize = sizeof(CURSORINFO);
                        if (cursor(&ci))
                                RAND_add(&ci, ci.cbSize, 2);
                        }

                if (queue)
                        {
                        /* message queue status */
                        /* assume 1 byte of entropy */
                        w = queue(QS_ALLEVENTS);
                        RAND_add(&w, sizeof(w), 1);
                        }

                FreeLibrary(user);
                }

        /* Toolhelp32 snapshot: enumerate processes, threads, modules and heap
         * http://msdn.microsoft.com/library/psdk/winbase/toolhelp_5pfd.htm
         * (Win 9x and 2000 only, not available on NT)
         *
         * This seeding method was proposed in Peter Gutmann, Software
         * Generation of Practically Strong Random Numbers,
         * http://www.usenix.org/publications/library/proceedings/sec98/gutmann.html
         * revised version at http://www.cryptoengines.com/~peter/06_random.pdf
         * (The assignment of entropy estimates below is arbitrary, but based
         * on Peter's analysis the full poll appears to be safe. Additional
         * interactive seeding is encouraged.)
         */

        if (kernel)
                {
                CREATETOOLHELP32SNAPSHOT snap;
                CLOSETOOLHELP32SNAPSHOT close_snap;
                HANDLE handle;

                HEAP32FIRST heap_first;
                HEAP32NEXT heap_next;
                HEAP32LIST heaplist_first, heaplist_next;
                PROCESS32 process_first, process_next;
                THREAD32 thread_first, thread_next;
                MODULE32 module_first, module_next;

                HEAPLIST32 hlist;
                HEAPENTRY32 hentry;
                PROCESSENTRY32 p;
                THREADENTRY32 t;
                MODULEENTRY32 m;
                DWORD stoptime = 0;

                snap = (CREATETOOLHELP32SNAPSHOT)
                        GetProcAddress(kernel, "CreateToolhelp32Snapshot");
                close_snap = (CLOSETOOLHELP32SNAPSHOT)
                        GetProcAddress(kernel, "CloseToolhelp32Snapshot");
                heap_first = (HEAP32FIRST) GetProcAddress(kernel, "Heap32First");
                heap_next = (HEAP32NEXT) GetProcAddress(kernel, "Heap32Next");
                heaplist_first = (HEAP32LIST) GetProcAddress(kernel, "Heap32ListFirst");
                heaplist_next = (HEAP32LIST) GetProcAddress(kernel, "Heap32ListNext");
                process_first = (PROCESS32) GetProcAddress(kernel, "Process32First");
                process_next = (PROCESS32) GetProcAddress(kernel, "Process32Next");
                thread_first = (THREAD32) GetProcAddress(kernel, "Thread32First");
                thread_next = (THREAD32) GetProcAddress(kernel, "Thread32Next");
                module_first = (MODULE32) GetProcAddress(kernel, "Module32First");
                module_next = (MODULE32) GetProcAddress(kernel, "Module32Next");

                if (snap && heap_first && heap_next && heaplist_first &&
                        heaplist_next && process_first && process_next &&
                        thread_first && thread_next && module_first &&
                        module_next && (handle = snap(TH32CS_SNAPALL,0))
                        != INVALID_HANDLE_VALUE)
                        {
                        /* heap list and heap walking */
                        /* HEAPLIST32 contains 3 fields that will change with
                         * each entry.  Consider each field a source of 1 byte
                         * of entropy.
                         * HEAPENTRY32 contains 5 fields that will change with 
                         * each entry.  Consider each field a source of 1 byte
                         * of entropy.
                         */
                        hlist.dwSize = sizeof(HEAPLIST32);              
                        if (good) stoptime = GetTickCount() + MAXDELAY;
                        if (heaplist_first(handle, &hlist))
                                do
                                        {
                                        RAND_add(&hlist, hlist.dwSize, 3);
                                        hentry.dwSize = sizeof(HEAPENTRY32);
                                        if (heap_first(&hentry,
                                                hlist.th32ProcessID,
                                                hlist.th32HeapID))
                                                {
                                                int entrycnt = 80;
                                                do
                                                        RAND_add(&hentry,
                                                                hentry.dwSize, 5);
                                                while (heap_next(&hentry)
                                                        && --entrycnt > 0);
                                                }
                                        } while (heaplist_next(handle,
                                                &hlist) && GetTickCount() < stoptime);

                        /* process walking */
                        /* PROCESSENTRY32 contains 9 fields that will change
                         * with each entry.  Consider each field a source of
                         * 1 byte of entropy.
                         */
                        p.dwSize = sizeof(PROCESSENTRY32);
                
                        if (good) stoptime = GetTickCount() + MAXDELAY;
                        if (process_first(handle, &p))
                                do
                                        RAND_add(&p, p.dwSize, 9);
                                while (process_next(handle, &p) && GetTickCount() < stoptime);

                        /* thread walking */
                        /* THREADENTRY32 contains 6 fields that will change
                         * with each entry.  Consider each field a source of
                         * 1 byte of entropy.
                         */
                        t.dwSize = sizeof(THREADENTRY32);
                        if (good) stoptime = GetTickCount() + MAXDELAY;
                        if (thread_first(handle, &t))
                                do
                                        RAND_add(&t, t.dwSize, 6);
                                while (thread_next(handle, &t) && GetTickCount() < stoptime);

                        /* module walking */
                        /* MODULEENTRY32 contains 9 fields that will change
                         * with each entry.  Consider each field a source of
                         * 1 byte of entropy.
                         */
                        m.dwSize = sizeof(MODULEENTRY32);
                        if (good) stoptime = GetTickCount() + MAXDELAY;
                        if (module_first(handle, &m))
                                do
                                        RAND_add(&m, m.dwSize, 9);
                                while (module_next(handle, &m)
                                                && (GetTickCount() < stoptime));
                        if (close_snap)
                                close_snap(handle);
                        else
                                CloseHandle(handle);

                        }

                FreeLibrary(kernel);
                }
        }
#endif /* !OPENSSL_SYS_WINCE */

        /* timer data */
        readtimer();
        
        /* memory usage statistics */
        GlobalMemoryStatus(&m);
        RAND_add(&m, sizeof(m), 1);

        /* process ID */
        w = GetCurrentProcessId();
        RAND_add(&w, sizeof(w), 1);

#if 0
        printf("Exiting RAND_poll\n");
#endif

        return(1);
}

int RAND_event(UINT iMsg, WPARAM wParam, LPARAM lParam)
        {
        double add_entropy=0;

        switch (iMsg)
                {
        case WM_KEYDOWN:
                        {
                        static WPARAM key;
                        if (key != wParam)
                                add_entropy = 0.05;
                        key = wParam;
                        }
                        break;
        case WM_MOUSEMOVE:
                        {
                        static int lastx,lasty,lastdx,lastdy;
                        int x,y,dx,dy;

                        x=LOWORD(lParam);
                        y=HIWORD(lParam);
                        dx=lastx-x;
                        dy=lasty-y;
                        if (dx != 0 && dy != 0 && dx-lastdx != 0 && dy-lastdy != 0)
                                add_entropy=.2;
                        lastx=x, lasty=y;
                        lastdx=dx, lastdy=dy;
                        }
                break;
                }

        readtimer();
        RAND_add(&iMsg, sizeof(iMsg), add_entropy);
        RAND_add(&wParam, sizeof(wParam), 0);
        RAND_add(&lParam, sizeof(lParam), 0);
 
        return (RAND_status());
        }


void RAND_screen(void) /* function available for backward compatibility */
{
        RAND_poll();
        readscreen();
}


/* feed timing information to the PRNG */
static void readtimer(void)
{
        DWORD w;
        LARGE_INTEGER l;
        static int have_perfc = 1;
#if defined(_MSC_VER) && defined(_M_X86)
        static int have_tsc = 1;
        DWORD cyclecount;

        if (have_tsc) {
          __try {
            __asm {
              _emit 0x0f
              _emit 0x31
              mov cyclecount, eax
              }
            RAND_add(&cyclecount, sizeof(cyclecount), 1);
          } __except(EXCEPTION_EXECUTE_HANDLER) {
            have_tsc = 0;
          }
        }
#else
# define have_tsc 0
#endif

        if (have_perfc) {
          if (QueryPerformanceCounter(&l) == 0)
            have_perfc = 0;
          else
            RAND_add(&l, sizeof(l), 0);
        }

        if (!have_tsc && !have_perfc) {
          w = GetTickCount();
          RAND_add(&w, sizeof(w), 0);
        }
}

/* feed screen contents to PRNG */
/*****************************************************************************
 *
 * Created 960901 by Gertjan van Oosten, gertjan@West.NL, West Consulting B.V.
 *
 * Code adapted from
 * <URL:http://support.microsoft.com/default.aspx?scid=kb;[LN];97193>;
 * the original copyright message is:
 *
 *   (C) Copyright Microsoft Corp. 1993.  All rights reserved.
 *
 *   You have a royalty-free right to use, modify, reproduce and
 *   distribute the Sample Files (and/or any modified version) in
 *   any way you find useful, provided that you agree that
 *   Microsoft has no warranty obligations or liability for any
 *   Sample Application Files which are modified.
 */

static void readscreen(void)
{
#if !defined(OPENSSL_SYS_WINCE) && !defined(OPENSSL_SYS_WIN32_CYGWIN)
  HDC           hScrDC;         /* screen DC */
  HDC           hMemDC;         /* memory DC */
  HBITMAP       hBitmap;        /* handle for our bitmap */
  HBITMAP       hOldBitmap;     /* handle for previous bitmap */
  BITMAP        bm;             /* bitmap properties */
  unsigned int  size;           /* size of bitmap */
  char          *bmbits;        /* contents of bitmap */
  int           w;              /* screen width */
  int           h;              /* screen height */
  int           y;              /* y-coordinate of screen lines to grab */
  int           n = 16;         /* number of screen lines to grab at a time */

  if (GetVersion() >= 0x80000000 || !OPENSSL_isservice())
    return;

  /* Create a screen DC and a memory DC compatible to screen DC */
  hScrDC = CreateDC(TEXT("DISPLAY"), NULL, NULL, NULL);
  hMemDC = CreateCompatibleDC(hScrDC);

  /* Get screen resolution */
  w = GetDeviceCaps(hScrDC, HORZRES);
  h = GetDeviceCaps(hScrDC, VERTRES);

  /* Create a bitmap compatible with the screen DC */
  hBitmap = CreateCompatibleBitmap(hScrDC, w, n);

  /* Select new bitmap into memory DC */
  hOldBitmap = SelectObject(hMemDC, hBitmap);

  /* Get bitmap properties */
  GetObject(hBitmap, sizeof(BITMAP), (LPSTR)&bm);
  size = (unsigned int)bm.bmWidthBytes * bm.bmHeight * bm.bmPlanes;

  bmbits = OPENSSL_malloc(size);
  if (bmbits) {
    /* Now go through the whole screen, repeatedly grabbing n lines */
    for (y = 0; y < h-n; y += n)
        {
        unsigned char md[MD_DIGEST_LENGTH];

        /* Bitblt screen DC to memory DC */
        BitBlt(hMemDC, 0, 0, w, n, hScrDC, 0, y, SRCCOPY);

        /* Copy bitmap bits from memory DC to bmbits */
        GetBitmapBits(hBitmap, size, bmbits);

        /* Get the hash of the bitmap */
        MD(bmbits,size,md);

        /* Seed the random generator with the hash value */
        RAND_add(md, MD_DIGEST_LENGTH, 0);
        }

    OPENSSL_free(bmbits);
  }

  /* Select old bitmap back into memory DC */
  hBitmap = SelectObject(hMemDC, hOldBitmap);

  /* Clean up */
  DeleteObject(hBitmap);
  DeleteDC(hMemDC);
  DeleteDC(hScrDC);
#endif /* !OPENSSL_SYS_WINCE */
}

#endif