Use dynamic buffer for token buffer in win32 admin check

Magnus Hagander

diff --git a/src/backend/port/win32/security.c b/src/backend/port/win32/security.c
index acc2f41343cff49deb7bb3b613812276a29db6e4..9a7727b34e0d20b776cd80d22fda4a38deb60ba9 100644 (file)
--- a/src/backend/port/win32/security.c
+++ b/src/backend/port/win32/security.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/port/win32/security.c,v 1.1 2004/06/24 21:02:42 tgl Exp $
+ *   $PostgreSQL: pgsql/src/backend/port/win32/security.c,v 1.2 2004/08/28 21:00:35 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -25,8 +25,8 @@ int
 pgwin32_is_admin(void)
 {
    HANDLE AccessToken;
-   UCHAR InfoBuffer[1024];
-   PTOKEN_GROUPS Groups = (PTOKEN_GROUPS)InfoBuffer; 
+   char *InfoBuffer = NULL;
+   PTOKEN_GROUPS Groups;
    DWORD InfoBufferSize;
    PSID AdministratorsSid;
    PSID PowerUsersSid;
@@ -41,8 +41,30 @@ pgwin32_is_admin(void)
        exit(1);
    }
 
+   if (GetTokenInformation(AccessToken,TokenGroups,NULL,0,&InfoBufferSize))
+   {
+       write_stderr("failed to get token information - got zero size!\n");
+       exit(1);
+   }
+
+   if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
+   {
+       write_stderr("failed to get token information: %d\n",
+                    (int)GetLastError());
+       exit(1);
+   }
+
+   InfoBuffer = malloc(InfoBufferSize);
+   if (!InfoBuffer)
+   {
+       write_stderr("failed to allocate %i bytes for token information!\n",
+                    (int)InfoBufferSize);
+       exit(1);
+   }
+   Groups = (PTOKEN_GROUPS)InfoBuffer; 
+
    if (!GetTokenInformation(AccessToken,TokenGroups,InfoBuffer,
-                            1024, &InfoBufferSize))
+                            InfoBufferSize, &InfoBufferSize))
    {
        write_stderr("failed to get token information: %d\n",
                     (int)GetLastError());
@@ -81,6 +103,7 @@ pgwin32_is_admin(void)
        }
    }
    
+   free(InfoBuffer);
    FreeSid(AdministratorsSid);
    FreeSid(PowerUsersSid);
    return success;