When looking for a local username on Windows, if we can get hold of the

[u/mdw/putty] / windows / winmisc.c

diff --git a/windows/winmisc.c b/windows/winmisc.c
index e5143d9..c7ac835 100644 (file)
--- a/windows/winmisc.c
+++ b/windows/winmisc.c
@@ -5,6 +5,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include "putty.h"
+#include <security.h>
 
 OSVERSIONINFO osVersion;
 
@@ -40,21 +41,61 @@ char *get_username(void)
 {
     DWORD namelen;
     char *user;
+    int got_username = FALSE;
+    DECL_WINDOWS_FUNCTION(static, BOOLEAN, GetUserNameExA,
+                         (EXTENDED_NAME_FORMAT, LPSTR, PULONG));
+
+    {
+       static int tried_usernameex = FALSE;
+       if (!tried_usernameex) {
+           /* Not available on Win9x, so load dynamically */
+           HMODULE secur32 = LoadLibrary("SECUR32.DLL");
+           GET_WINDOWS_FUNCTION(secur32, GetUserNameExA);
+           tried_usernameex = TRUE;
+       }
+    }
 
-    namelen = 0;
-    if (GetUserName(NULL, &namelen) == FALSE) {
+    if (p_GetUserNameExA) {
        /*
-        * Apparently this doesn't work at least on Windows XP SP2.
-        * Thus assume a maximum of 256. It will fail again if it
-        * doesn't fit.
+        * If available, use the principal -- this avoids the problem
+        * that the local username is case-insensitive but Kerberos
+        * usernames are case-sensitive.
         */
-       namelen = 256;
+
+       /* Get the length */
+       namelen = 0;
+       (void) p_GetUserNameExA(NameUserPrincipal, NULL, &namelen);
+
+       user = snewn(namelen, char);
+       got_username = p_GetUserNameExA(NameUserPrincipal, user, &namelen);
+       if (got_username) {
+           char *p = strchr(user, '@');
+           if (p) *p = 0;
+       } else {
+           sfree(user);
+       }
     }
 
-    user = snewn(namelen, char);
-    GetUserName(user, &namelen);
+    if (!got_username) {
+       /* Fall back to local user name */
+       namelen = 0;
+       if (GetUserName(NULL, &namelen) == FALSE) {
+           /*
+            * Apparently this doesn't work at least on Windows XP SP2.
+            * Thus assume a maximum of 256. It will fail again if it
+            * doesn't fit.
+            */
+           namelen = 256;
+       }
+
+       user = snewn(namelen, char);
+       got_username = GetUserName(user, &namelen);
+       if (!got_username) {
+           sfree(user);
+       }
+    }
 
-    return user;
+    return got_username ? user : NULL;
 }
 
 BOOL init_winver(void)