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;