* cygheap.h (enum impersonation): New enum.

	(cygheap_user::token): Delete.
	(cygheap_user::impersonated): Delete.
	(cygheap_user::external_token): New member.
	(cygheap_user::internal_token): New member.
	(cygheap_user::impersonation_state): New member.
	(cygheap_user::issetuid): Modify.
	(cygheap_user::token): New method.
	(cygheap_user::deimpersonate): New method.
	(cygheap_user::reimpersonate): New method.
	(cygheap_user::has_impersonation_tokens): New method.
	(cygheap_user::close_impersonation_tokens): New method.
	* dtable.cc (dtable::vfork_child_dup): Use new cygheap_user methods.
	* fhandler_socket.cc (fhandler_socket::dup): Ditto.
	* fork.cc (fork_child): Ditto.
	(fork_parent): Ditto.
	* grp.cc (internal_getgroups): Ditto.
	* security.cc (verify_token): Ditto.
	(check_file_access): Ditto.
	(cygwin_set_impersonation_token): Detect conflicts. Set
	user.external_token.
	* spawn.cc (spawn_guts): Use new cygheap_user methods.
	* syscalls.cc (seteuid32): Rearrange to use the two tokens
	in cygheap_user.
	(setegid32): Use new cygheap_user methods.
	* uinfo.cc: (internal_getlogin): Ditto.

1 files changed, 12 insertions, 6 deletions

diff --git a/winsup/cygwin/security.cc b/winsup/cygwin/security.cc
index 7bae8f4c7..5ccf37e3d 100644
--- a/winsup/cygwin/security.cc
+++ b/winsup/cygwin/security.cc
@@ -70,10 +70,16 @@ extern "C" void
 cygwin_set_impersonation_token (const HANDLE hToken)
 {
   debug_printf ("set_impersonation_token (%d)", hToken);
-  if (cygheap->user.token != hToken)
+  if (cygheap->user.impersonation_state == IMP_EXTERNAL
+      && cygheap->user.external_token != hToken)
     {
-      cygheap->user.token = hToken;
-      cygheap->user.impersonated = FALSE;
+      set_errno (EPERM);
+      return;
+    }
+  else
+    {
+      cygheap->user.external_token = hToken;
+      return;
     }
 }
 
@@ -717,7 +723,7 @@ verify_token (HANDLE token, cygsid &usersid, user_groups &groups, BOOL *pintern)
   if (pintern)
     {
       TOKEN_SOURCE ts;
-      if (!GetTokenInformation (cygheap->user.token, TokenSource,
+      if (!GetTokenInformation (token, TokenSource,
 				&ts, sizeof ts, &size))
 	debug_printf ("GetTokenInformation(): %E");
       else
@@ -1906,7 +1912,7 @@ check_file_access (const char *fn, int flags)
     goto done;
 
   if (cygheap->user.issetuid ())
-    hToken = cygheap->user.token;
+    hToken = cygheap->user.token ();
   else if (!OpenProcessToken (hMainProc, TOKEN_DUPLICATE, &hToken))
     {
       __seterrno ();
@@ -1914,7 +1920,7 @@ check_file_access (const char *fn, int flags)
     }
   if (!(status = DuplicateToken (hToken, SecurityIdentification, &hIToken)))
     __seterrno ();
-  if (hToken != cygheap->user.token)
+  if (!cygheap->user.issetuid ())
     CloseHandle (hToken);
   if (!status)
     goto done;