File pam_krb5-2.3.1-switch-perms-on-refresh.dif of Package pam_krb5

Index: pam_krb5-2.4.4/src/auth.c
===================================================================
--- pam_krb5-2.4.4.orig/src/auth.c
+++ pam_krb5-2.4.4/src/auth.c
@@ -56,6 +56,7 @@
 #include "items.h"
 #include "kuserok.h"
 #include "log.h"
+#include "perms.h"
 #include "options.h"
 #include "prompter.h"
 #include "session.h"
@@ -433,6 +434,7 @@ int
 pam_sm_setcred(pam_handle_t *pamh, int flags,
 	       int argc, PAM_KRB5_MAYBE_CONST char **argv)
 {
+	struct _pam_krb5_perms *saved_perms;
 	notice("pam_setcred (%s) called",
 		   (flags & PAM_ESTABLISH_CRED)?"establish credential":
 		   (flags & PAM_REINITIALIZE_CRED)?"reinitialize credential":
@@ -444,10 +446,22 @@ pam_sm_setcred(pam_handle_t *pamh, int f
 					      _pam_krb5_session_caller_setcred);
 	}
 	if (flags & (PAM_REINITIALIZE_CRED | PAM_REFRESH_CRED)) {
+		saved_perms = _pam_krb5_switch_perms_r2e();
+
 		if (_pam_krb5_sly_looks_unsafe() == 0) {
-			return _pam_krb5_sly_maybe_refresh(pamh, flags,
-							   argc, argv);
+			int i = _pam_krb5_sly_maybe_refresh(pamh, flags, argc, argv);
+			if (saved_perms != NULL) {
+				_pam_krb5_restore_perms_r2e(saved_perms);
+			}
+			saved_perms = NULL;
+
+			return i;
 		} else {
+			debug("looks unsafe - ignore refresh");
+			if (saved_perms != NULL) {
+				_pam_krb5_restore_perms_r2e(saved_perms);
+			}
+			saved_perms = NULL;
 			return PAM_IGNORE;
 		}
 	}
Index: pam_krb5-2.4.4/src/perms.c
===================================================================
--- pam_krb5-2.4.4.orig/src/perms.c
+++ pam_krb5-2.4.4/src/perms.c
@@ -89,3 +89,49 @@ _pam_krb5_restore_perms(struct _pam_krb5
 	}
 	return ret;
 }
+
+struct _pam_krb5_perms *
+_pam_krb5_switch_perms_r2e(void)
+{
+	struct _pam_krb5_perms *ret;
+	ret = malloc(sizeof(*ret));
+	if (ret != NULL) {
+		ret->ruid = getuid();
+		ret->euid = geteuid();
+		ret->rgid = getgid();
+		ret->egid = getegid();
+		if (ret->ruid == ret->euid) {
+			ret->ruid = -1;
+			ret->euid = -1;
+		}
+		if (ret->rgid == ret->egid) {
+			ret->rgid = -1;
+			ret->egid = -1;
+		}
+		if (setresgid(ret->rgid, ret->rgid, ret->egid) == -1) {
+			free(ret);
+			ret = NULL;
+		} else {
+			if (setresuid(ret->ruid, ret->ruid, ret->euid) == -1) {
+				setresgid(ret->rgid, ret->egid, ret->rgid);
+				free(ret);
+				ret = NULL;
+			}
+		}
+	}
+	return ret;
+}
+
+int
+_pam_krb5_restore_perms_r2e(struct _pam_krb5_perms *saved)
+{
+	int ret = -1;
+	if (saved != NULL) {
+		if ((setresuid(saved->ruid, saved->euid, saved->ruid) == 0) &&
+		    (setresgid(saved->rgid, saved->egid, saved->rgid) == 0)) {
+			ret = 0;
+		}
+		free(saved);
+	}
+	return ret;
+}
Index: pam_krb5-2.4.4/src/perms.h
===================================================================
--- pam_krb5-2.4.4.orig/src/perms.h
+++ pam_krb5-2.4.4/src/perms.h
@@ -37,4 +37,7 @@ struct _pam_krb5_perms;
 struct _pam_krb5_perms *_pam_krb5_switch_perms(void);
 int _pam_krb5_restore_perms(struct _pam_krb5_perms *saved);
 
+struct _pam_krb5_perms *_pam_krb5_switch_perms_r2e(void);
+int _pam_krb5_restore_perms_r2e(struct _pam_krb5_perms *saved);
+
 #endif