Changes by Jeffrey Altman <jaltman@columbia.edu> to make RAND_poll()
authorRichard Levitte <levitte@openssl.org>
Thu, 21 Sep 2000 07:02:27 +0000 (07:02 +0000)
committerRichard Levitte <levitte@openssl.org>
Thu, 21 Sep 2000 07:02:27 +0000 (07:02 +0000)
work better in Win32.  Verified by zhu qun-ying <qyzhu@krdl.org.sg>.

crypto/rand/rand_win.c

index d3fe50d..9f2dcff 100644 (file)
@@ -171,13 +171,16 @@ typedef BOOL (WINAPI *MODULE32)(HANDLE, LPMODULEENTRY32);
 
 #include <lmcons.h>
 #include <lmstats.h>
-#if 0 /* Some compilers use LMSTR, others (VC6, for example) use LPTSTR.
-       * This part is disabled until a fix is found.
+#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)
-        (LMSTR, LMSTR, DWORD, DWORD, LPBYTE*);
+        (LPWSTR, LPWSTR, DWORD, DWORD, LPBYTE*);
 typedef NET_API_STATUS (NET_API_FUNCTION * NETFREE)(LPBYTE);
-#endif /* 0 */
+#endif /* 1 */
 
 int RAND_poll(void)
 {
@@ -191,12 +194,20 @@ int RAND_poll(void)
        CRYPTACQUIRECONTEXT acquire = 0;
        CRYPTGENRANDOM gen = 0;
        CRYPTRELEASECONTEXT release = 0;
-#if 0 /* This part is disabled until a fix for the problem with the
-       * definition of NETSTATGET is found.
+#if 1 /* There was previously a problem with NETSTATGET.  Currently, this
+       * section is still experimental, but if all goes well, this conditional
+       * will be removed
        */
        NETSTATGET netstatget = 0;
        NETFREE netfree = 0;
-#endif /* 0 */
+#endif /* 1 */
+
+       /* 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 ) ;
 
        /* load functions dynamically - not available on all systems */
        advapi = LoadLibrary("ADVAPI32.DLL");
@@ -204,9 +215,9 @@ int RAND_poll(void)
        user = LoadLibrary("USER32.DLL");
        netapi = LoadLibrary("NETAPI32.DLL");
 
-#if 0 /* This part is disabled until a fix for the problem with the
-       * definition of NETSTATGET is found.  Also, note that VC6 doesn't
-       * understand strings starting with L".
+#if 1 /* There was previously a problem with NETSTATGET.  Currently, this
+       * section is still experimental, but if all goes well, this conditional
+       * will be removed
        */
        if (netapi)
                {
@@ -217,57 +228,68 @@ int RAND_poll(void)
        if (netstatget && netfree)
                {
                LPBYTE outbuf;
-               /* NetStatisticsGet() is a Unicode only function */
+               /* 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), 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), 0);
+                       RAND_add(outbuf, sizeof(STAT_SERVER_0), 17);
                        netfree(outbuf);
                        }
                }
 
        if (netapi)
                FreeLibrary(netapi);
-#endif /* 0 */
+#endif /* 1 */
  
-#if 0 /* It appears like this can cause an exception deep within ADVAPI32.DLL
-       * at random times.  Reported by Jeffrey Altman.
-       */
-       /* 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, "Global",
-                       NULL, NULL, buf, &length);
-               }
-       if (rc == ERROR_SUCCESS)
+        /* 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.
+        */
+        if ( osverinfo.dwPlatformId == VER_PLATFORM_WIN32_NT &&
+               osverinfo.dwMajorVersion < 5)
                {
-               RAND_add(&length, sizeof(length), 0);
-               RAND_add(buf, length, 0);
+               /* 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, "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);
+                       }
+               if (buf)
+                       free(buf);
                }
-       if (buf)
-               free(buf);
-       }
-#endif /* 0 */
 
        if (advapi)
                {
@@ -282,12 +304,13 @@ int RAND_poll(void)
        if (acquire && gen && release)
                {
                /* poll the CryptoAPI PRNG */
+                /* The CryptoAPI returns sizeof(buf) bytes of randomness */
                if (acquire(&hProvider, 0, 0, PROV_RSA_FULL,
                        CRYPT_VERIFYCONTEXT))
                        {
                        if (gen(hProvider, sizeof(buf), buf) != 0)
                                {
-                               RAND_add(buf, sizeof(buf), 0);
+                               RAND_add(buf, sizeof(buf), sizeof(buf));
 #ifdef DEBUG
                                printf("randomness from PROV_RSA_FULL\n");
 #endif
@@ -300,7 +323,7 @@ int RAND_poll(void)
                        {
                        if (gen(hProvider, sizeof(buf), buf) != 0)
                                {
-                               RAND_add(buf, sizeof(buf), 0);
+                               RAND_add(buf, sizeof(buf), sizeof(buf));
 #ifdef DEBUG
                                printf("randomness from PROV_INTEL_SEC\n");
 #endif
@@ -321,7 +344,7 @@ int RAND_poll(void)
 
        /* process ID */
        w = GetCurrentProcessId();
-       RAND_add(&w, sizeof(w), 0);
+       RAND_add(&w, sizeof(w), 1);
 
        if (user)
                {
@@ -334,41 +357,37 @@ int RAND_poll(void)
                queue = (GETQUEUESTATUS) GetProcAddress(user, "GetQueueStatus");
 
                if (win)
-               {
+                       {
                        /* window handle */
                        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.
                         */
-                       OSVERSIONINFO osverinfo ;
-                       osverinfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFO) ;
-                       GetVersionEx( &osverinfo ) ;
-
                        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, 0);
+                               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), 0);
+                       RAND_add(&w, sizeof(w), 1);
                        }
 
                FreeLibrary(user);
@@ -406,7 +425,7 @@ int RAND_poll(void)
                MODULEENTRY32 m;
 
                snap = (CREATETOOLHELP32SNAPSHOT)
-                 GetProcAddress(kernel, "CreateToolhelp32Snapshot");
+                       GetProcAddress(kernel, "CreateToolhelp32Snapshot");
                heap_first = (HEAP32FIRST) GetProcAddress(kernel, "Heap32First");
                heap_next = (HEAP32NEXT) GetProcAddress(kernel, "Heap32Next");
                heaplist_first = (HEAP32LIST) GetProcAddress(kernel, "Heap32ListFirst");
@@ -425,11 +444,18 @@ int RAND_poll(void)
                        != NULL)
                        {
                        /* 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 (heaplist_first(handle, &hlist))
                                do
                                        {
-                                       RAND_add(&hlist, hlist.dwSize, 0);
+                                       RAND_add(&hlist, hlist.dwSize, 3);
                                        hentry.dwSize = sizeof(HEAPENTRY32);
                                        if (heap_first(&hentry,
                                                hlist.th32ProcessID,
@@ -438,34 +464,46 @@ int RAND_poll(void)
                                                int entrycnt = 50;
                                                do
                                                        RAND_add(&hentry,
-                                                               hentry.dwSize, 0);
+                                                               hentry.dwSize, 5);
                                                while (heap_next(&hentry)
                                                        && --entrycnt > 0);
                                                }
                                        } while (heaplist_next(handle,
                                                &hlist));
-
+                       
                        /* 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 (process_first(handle, &p))
                                do
-                                       RAND_add(&p, p.dwSize, 0);
+                                       RAND_add(&p, p.dwSize, 9);
                                while (process_next(handle, &p));
-                       
+
                        /* 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 (thread_first(handle, &t))
                                do
-                                       RAND_add(&t, t.dwSize, 0);
+                                       RAND_add(&t, t.dwSize, 6);
                                while (thread_next(handle, &t));
-                       
+
                        /* 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 (module_first(handle, &m))
                                do
-                                       RAND_add(&m, m.dwSize, 1);
+                                       RAND_add(&m, m.dwSize, 9);
                                while (module_next(handle, &m));
-                       
+
                        CloseHandle(handle);
                        }