*/
#include "includes.h"
-RCSID("$OpenBSD: uidswap.c,v 1.15 2001/04/08 11:24:33 markus Exp $");
+RCSID("$OpenBSD: uidswap.c,v 1.16 2001/04/20 16:32:22 markus Exp $");
#include "log.h"
#include "uidswap.h"
* POSIX saved uids or not.
*/
+#if defined(_POSIX_SAVED_IDS) && !defined(BROKEN_SAVED_UIDS)
/* Lets assume that posix saved ids also work with seteuid, even though that
is not part of the posix specification. */
-
+#define SAVED_IDS_WORK_WITH_SETEUID
+/* Saved effective uid. */
+static uid_t saved_euid = 0;
+static gid_t saved_egid = 0;
+#endif
+
/* Saved effective uid. */
static int privileged = 0;
static int temporarily_use_uid_effective = 0;
-static uid_t saved_euid = 0;
-static gid_t saved_egid;
static gid_t saved_egroups[NGROUPS_MAX], user_groups[NGROUPS_MAX];
static int saved_egroupslen = -1, user_groupslen = -1;
-
+
/*
* Temporarily changes to the given uid. If the effective user
* id is not root, this does nothing. This call cannot be nested.
void
temporarily_use_uid(struct passwd *pw)
{
- /* Save the current euid, and egroups. */
- saved_euid = geteuid();
- debug("temporarily_use_uid: %d/%d (e=%d)",
- pw->pw_uid, pw->pw_gid, saved_euid);
- if (saved_euid != 0) {
- privileged = 0;
- return;
- }
- privileged = 1;
- temporarily_use_uid_effective = 1;
+ /* Save the current euid, and egroups. */
+#ifdef SAVED_IDS_WORK_WITH_SETEUID
+ saved_euid = geteuid();
saved_egid = getegid();
- saved_egroupslen = getgroups(NGROUPS_MAX, saved_egroups);
- if (saved_egroupslen < 0)
- fatal("getgroups: %.100s", strerror(errno));
-
- /* set and save the user's groups */
- if (user_groupslen == -1) {
- if (initgroups(pw->pw_name, pw->pw_gid) < 0)
- fatal("initgroups: %s: %.100s", pw->pw_name,
- strerror(errno));
- user_groupslen = getgroups(NGROUPS_MAX, user_groups);
- if (user_groupslen < 0)
- fatal("getgroups: %.100s", strerror(errno));
- }
- /* Set the effective uid to the given (unprivileged) uid. */
+ debug("temporarily_use_uid: %d/%d (e=%d)",
+ pw->pw_uid, pw->pw_gid, saved_euid);
+ if (saved_euid != 0) {
+ privileged = 0;
+ return;
+ }
+#else
+ if (geteuid() != 0) {
+ privileged = 0;
+ return;
+ }
+#endif /* SAVED_IDS_WORK_WITH_SETEUID */
+
+ privileged = 1;
+ temporarily_use_uid_effective = 1;
+ saved_egroupslen = getgroups(NGROUPS_MAX, saved_egroups);
+ if (saved_egroupslen < 0)
+ fatal("getgroups: %.100s", strerror(errno));
+
+ /* set and save the user's groups */
+ if (user_groupslen == -1) {
+ if (initgroups(pw->pw_name, pw->pw_gid) < 0)
+ fatal("initgroups: %s: %.100s", pw->pw_name,
+ strerror(errno));
+ user_groupslen = getgroups(NGROUPS_MAX, user_groups);
+ if (user_groupslen < 0)
+ fatal("getgroups: %.100s", strerror(errno));
+ }
+#ifndef HAVE_CYGWIN
+ /* Set the effective uid to the given (unprivileged) uid. */
if (setgroups(user_groupslen, user_groups) < 0)
fatal("setgroups: %.100s", strerror(errno));
- pw->pw_gid = pw->pw_gid;
+#endif /* !HAVE_CYWIN */
+#ifndef SAVED_IDS_WORK_WITH_SETEUID
+ /* Propagate the privileged gid to all of our gids. */
+ if (setgid(getegid()) < 0)
+ debug("setgid %u: %.100s", (u_int) getegid(), strerror(errno));
+ /* Propagate the privileged uid to all of our uids. */
+ if (setuid(geteuid()) < 0)
+ debug("setuid %u: %.100s", (u_int) geteuid(), strerror(errno));
+#endif /* SAVED_IDS_WORK_WITH_SETEUID */
if (setegid(pw->pw_gid) < 0)
- fatal("setegid %u: %.100s", (u_int) pw->pw_gid,
- strerror(errno));
- if (seteuid(pw->pw_uid) == -1)
- fatal("seteuid %u: %.100s", (u_int) pw->pw_uid,
- strerror(errno));
+ fatal("setegid %u: %.100s", (u_int) pw->pw_gid,
+ strerror(errno));
+ if (seteuid(pw->pw_uid) == -1)
+ fatal("seteuid %u: %.100s", (u_int) pw->pw_uid,
+ strerror(errno));
}
-
+
/*
- * Restores to the original uid.
+ * Restores to the original (privileged) uid.
*/
void
restore_uid(void)
return;
if (!temporarily_use_uid_effective)
fatal("restore_uid: temporarily_use_uid not effective");
- /* Set the effective uid back to the saved uid. */
+
+#ifdef SAVED_IDS_WORK_WITH_SETEUID
+ /* Set the effective uid back to the saved privileged uid. */
if (seteuid(saved_euid) < 0)
- fatal("seteuid %u: %.100s", (u_int) saved_euid, strerror(errno));
+ fatal("seteuid %u: %.100s", (u_int) saved_euid,
+ strerror(errno));
+ if (setegid(saved_egid) < 0)
+ fatal("setegid %u: %.100s", (u_int) saved_egid,
+ strerror(errno));
+#else /* SAVED_IDS_WORK_WITH_SETEUID */
+ /*
+ * We are unable to restore the real uid to its unprivileged value.
+ * Propagate the real uid (usually more privileged) to effective uid
+ * as well.
+ */
+ setuid(getuid());
+ setgid(getgid());
+#endif /* SAVED_IDS_WORK_WITH_SETEUID */
+
+#ifndef HAVE_CYGWIN
if (setgroups(saved_egroupslen, saved_egroups) < 0)
fatal("setgroups: %.100s", strerror(errno));
- if (setegid(saved_egid) < 0)
- fatal("setegid %u: %.100s", (u_int) saved_egid, strerror(errno));
+#endif /* !HAVE_CYGWIN */
temporarily_use_uid_effective = 0;
}
{
if (temporarily_use_uid_effective)
fatal("restore_uid: temporarily_use_uid effective");
- if (setuid(pw->pw_uid) < 0)
- fatal("setuid %u: %.100s", (u_int) pw->pw_uid, strerror(errno));
if (setgid(pw->pw_gid) < 0)
fatal("setgid %u: %.100s", (u_int) pw->pw_gid, strerror(errno));
+ if (setuid(pw->pw_uid) < 0)
+ fatal("setuid %u: %.100s", (u_int) pw->pw_uid, strerror(errno));
}
andersk / openssh.git / blobdiff