From 0c00989f5bdaf9adf6d243455fbc7056bd0013f5 Mon Sep 17 00:00:00 2001
From: Greg Hudson <ghudson@mit.edu>
Date: Fri, 28 Feb 2014 14:49:35 -0500
Subject: [PATCH] Use preauth options when changing password
If we try to change the password in rb5_get_init_creds_password, we
must use all application-specified gic options which affect
preauthentication when getting the kadmin/changepw ticket. Create a
helper function make_chpw_options which copies the application's
options, unsets the options we don't want, and sets options
appropriate for a temporary ticket.
ticket: 7868
npmccallum:
* include tests from 06817686bfdef99523f300464bcbb0c8b037a27d
* backport from 1.12 to 1.11
---
src/lib/krb5/krb/gic_pwd.c | 63 +++++++++++++++++++++++++++++++++++++---------
src/tests/Makefile.in | 1 +
src/tests/t_changepw.py | 37 +++++++++++++++++++++++++++
3 files changed, 89 insertions(+), 12 deletions(-)
create mode 100644 src/tests/t_changepw.py
diff --git a/src/lib/krb5/krb/gic_pwd.c b/src/lib/krb5/krb/gic_pwd.c
index 9fdb8934a0765395ebc2b875d31b393d954bcbb4..c6c3161ca777698f0a7cbb789df34e51fa85b12c 100644
--- a/src/lib/krb5/krb/gic_pwd.c
+++ b/src/lib/krb5/krb/gic_pwd.c
@@ -241,6 +241,54 @@ warn_pw_expiry(krb5_context context, krb5_get_init_creds_opt *options,
(*prompter)(context, data, 0, banner, 0, 0);
}
+/*
+ * Create a temporary options structure for getting a kadmin/changepw ticket,
+ * based on the appplication-specified options. Propagate all application
+ * options which affect preauthentication, but not options which affect the
+ * resulting ticket or how it is stored. Set lifetime and flags appropriate
+ * for a ticket which we will use immediately and then discard.
+ *
+ * storage1 and storage2 will be used to hold the temporary options. The
+ * caller must not free the result, as it will contain aliases into the
+ * application options.
+ */
+static krb5_get_init_creds_opt *
+make_chpw_options(krb5_get_init_creds_opt *in, krb5_gic_opt_ext *storage1,
+ krb5_gic_opt_private *storage2)
+{
+ krb5_gic_opt_ext *in_ext;
+ krb5_get_init_creds_opt *opt;
+
+ /* Copy the application's options to storage. */
+ if (in == NULL) {
+ storage1->flags = 0;
+ } else if (krb5_gic_opt_is_extended(in)) {
+ in_ext = (krb5_gic_opt_ext *)in;
+ *storage1 = *in_ext;
+ *storage2 = *in_ext->opt_private;
+ storage1->opt_private = storage2;
+ } else {
+ *(krb5_get_init_creds_opt *)storage1 = *in;
+ }
+
+ /* Get a non-forwardable, non-proxiable, short-lifetime ticket. */
+ opt = (krb5_get_init_creds_opt *)storage1;
+ krb5_get_init_creds_opt_set_tkt_life(opt, 5 * 60);
+ krb5_get_init_creds_opt_set_renew_life(opt, 0);
+ krb5_get_init_creds_opt_set_forwardable(opt, 0);
+ krb5_get_init_creds_opt_set_proxiable(opt, 0);
+
+ /* Unset options which should only apply to the actual ticket. */
+ opt->flags &= ~KRB5_GET_INIT_CREDS_OPT_ADDRESS_LIST;
+ opt->flags &= ~KRB5_GET_INIT_CREDS_OPT_ANONYMOUS;
+
+ /* The output ccache should only be used for the actual ticket. */
+ if (krb5_gic_opt_is_extended(opt))
+ storage2->out_ccache = NULL;
+
+ return opt;
+}
+
krb5_error_code KRB5_CALLCONV
krb5_get_init_creds_password(krb5_context context,
krb5_creds *creds,
@@ -258,6 +306,8 @@ krb5_get_init_creds_password(krb5_context context,
int tries;
krb5_creds chpw_creds;
krb5_get_init_creds_opt *chpw_opts = NULL;
+ krb5_gic_opt_ext storage1;
+ krb5_gic_opt_private storage2;
struct gak_password gakpw;
krb5_data pw0, pw1;
char banner[1024], pw0array[1024], pw1array[1024];
@@ -347,16 +397,7 @@ krb5_get_init_creds_password(krb5_context context,
/* ok, we have an expired password. Give the user a few chances
to change it */
- /* use a minimal set of options */
-
- ret = krb5_get_init_creds_opt_alloc(context, &chpw_opts);
- if (ret)
- goto cleanup;
- krb5_get_init_creds_opt_set_tkt_life(chpw_opts, 5*60);
- krb5_get_init_creds_opt_set_renew_life(chpw_opts, 0);
- krb5_get_init_creds_opt_set_forwardable(chpw_opts, 0);
- krb5_get_init_creds_opt_set_proxiable(chpw_opts, 0);
-
+ chpw_opts = make_chpw_options(options, &storage1, &storage2);
if ((ret = krb5int_get_init_creds(context, &chpw_creds, client,
prompter, data,
start_time, "kadmin/changepw", chpw_opts,
@@ -473,8 +514,6 @@ cleanup:
warn_pw_expiry(context, options, prompter, data, in_tkt_service,
as_reply);
- if (chpw_opts)
- krb5_get_init_creds_opt_free(context, chpw_opts);
zapfree(gakpw.storage.data, gakpw.storage.length);
memset(pw0array, 0, sizeof(pw0array));
memset(pw1array, 0, sizeof(pw1array));
diff --git a/src/tests/Makefile.in b/src/tests/Makefile.in
index 9f76e9a7fad23e03b37e067d58c75fd7eaa8e673..74a6bdcff95618b6c9c77d5b50a243790af557e3 100644
--- a/src/tests/Makefile.in
+++ b/src/tests/Makefile.in
@@ -71,6 +71,7 @@ check-pytests:: hist t_init_creds
$(RUNPYTEST) $(srcdir)/t_iprop.py $(PYTESTFLAGS)
$(RUNPYTEST) $(srcdir)/t_anonpkinit.py $(PYTESTFLAGS)
$(RUNPYTEST) $(srcdir)/t_lockout.py $(PYTESTFLAGS)
+ $(RUNPYTEST) $(srcdir)/t_changepw.py $(PYTESTFLAGS)
$(RUNPYTEST) $(srcdir)/t_kadm5_hook.py $(PYTESTFLAGS)
$(RUNPYTEST) $(srcdir)/t_kdb_locking.py $(PYTESTFLAGS)
$(RUNPYTEST) $(srcdir)/t_keyrollover.py $(PYTESTFLAGS)
diff --git a/src/tests/t_changepw.py b/src/tests/t_changepw.py
new file mode 100644
index 0000000000000000000000000000000000000000..0b9832668e618b3db8d88cf388ec918898bb4df3
--- /dev/null
+++ b/src/tests/t_changepw.py
@@ -0,0 +1,37 @@
+#!/usr/bin/python
+from k5test import *
+
+# This file is intended to cover any password-changing mechanism. For
+# now it only contains a regression test for #7868.
+
+realm = K5Realm(create_host=False, get_creds=False, start_kadmind=True)
+
+# Mark a principal as expired and change its password through kinit.
+realm.run_kadminl('modprinc -pwexpire "1 day ago" user')
+pwinput = password('user') + '\nabcd\nabcd\n'
+realm.run([kinit, realm.user_princ], input=pwinput)
+
+# Do the same thing with FAST, with tracing turned on.
+realm.run_kadminl('modprinc -pwexpire "1 day ago" user')
+pwinput = 'abcd\nefgh\nefgh\n'
+tracefile = os.path.join(realm.testdir, 'trace')
+realm.run(['env', 'KRB5_TRACE=' + tracefile, kinit, '-T', realm.ccache,
+ realm.user_princ], input=pwinput)
+
+# Read the trace and check that FAST was used when getting the
+# kadmin/changepw ticket.
+f = open(tracefile, 'r')
+trace = f.read()
+f.close()
+getting_changepw = fast_used_for_changepw = False
+for line in trace.splitlines():
+ if 'Getting initial credentials for user@' in line:
+ getting_changepw_ticket = False
+ if 'Setting initial creds service to kadmin/changepw' in line:
+ getting_changepw_ticket = True
+ if getting_changepw_ticket and 'Using FAST' in line:
+ fast_used_for_changepw = True
+if not fast_used_for_changepw:
+ fail('FAST was not used to get kadmin/changepw ticket')
+
+success('Password change tests')
--
1.8.5.3