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/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
* Copyright 2009 by the Massachusetts Institute of Technology.
* All Rights Reserved.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "common.h"
/*
* Test program for protocol transition (S4U2Self) and constrained delegation
* (S4U2Proxy)
*
* Note: because of name canonicalization, the following tips may help
* when configuring with Active Directory:
*
* - Create a computer account FOO$
* - Set the UPN to host/foo.domain (no suffix); this is necessary to
* be able to send an AS-REQ as this principal, otherwise you would
* need to use the canonical name (FOO$), which will cause principal
* comparison errors in gss_accept_sec_context().
* - Add a SPN of host/foo.domain
* - Configure the computer account to support constrained delegation with
* protocol transition (Trust this computer for delegation to specified
* services only / Use any authentication protocol)
* - Add host/foo.domain to the keytab (possibly easiest to do this
* with ktadd)
*
* For S4U2Proxy to work the TGT must be forwardable too.
*
* Usage eg:
*
* kinit -k -t test.keytab -f 'host/test.win.mit.edu@WIN.MIT.EDU'
* ./t_s4u p:delegtest@WIN.MIT.EDU p:HOST/WIN-EQ7E4AA2WR8.win.mit.edu@WIN.MIT.EDU test.keytab
*/
static int use_spnego = 0;
static void
test_prf(gss_ctx_id_t initiatorContext, gss_ctx_id_t acceptorContext,
int flags)
{
gss_buffer_desc constant;
OM_uint32 major, minor;
unsigned int i;
gss_buffer_desc initiatorPrf;
gss_buffer_desc acceptorPrf;
constant.value = "gss prf test";
constant.length = strlen((char *)constant.value);
initiatorPrf.value = NULL;
acceptorPrf.value = NULL;
major = gss_pseudo_random(&minor, initiatorContext, flags, &constant, 19,
&initiatorPrf);
check_gsserr("gss_pseudo_random", major, minor);
printf("%s\n", flags == GSS_C_PRF_KEY_FULL ?
"PRF_KEY_FULL" : "PRF_KEY_PARTIAL");
printf("Initiator PRF: ");
for (i = 0; i < initiatorPrf.length; i++)
printf("%02x ", ((char *)initiatorPrf.value)[i] & 0xFF);
printf("\n");
major = gss_pseudo_random(&minor, acceptorContext, flags, &constant, 19,
&acceptorPrf);
check_gsserr("gss_pseudo_random", major, minor);
printf("Acceptor PRF: ");
for (i = 0; i < acceptorPrf.length; i++)
printf("%02x ", ((char *)acceptorPrf.value)[i] & 0xFF);
printf("\n");
if (acceptorPrf.length != initiatorPrf.length ||
memcmp(acceptorPrf.value, initiatorPrf.value, initiatorPrf.length)) {
fprintf(stderr, "Initiator and acceptor PRF output does not match\n");
exit(1);
}
(void)gss_release_buffer(&minor, &initiatorPrf);
(void)gss_release_buffer(&minor, &acceptorPrf);
}
static void
init_accept_sec_context(gss_cred_id_t claimant_cred_handle,
gss_cred_id_t verifier_cred_handle,
gss_cred_id_t *deleg_cred_handle)
{
OM_uint32 major, minor, flags;
gss_name_t source_name = GSS_C_NO_NAME, target_name = GSS_C_NO_NAME;
gss_ctx_id_t initiator_context, acceptor_context;
gss_OID mech;
*deleg_cred_handle = GSS_C_NO_CREDENTIAL;
major = gss_inquire_cred(&minor, verifier_cred_handle, &target_name, NULL,
NULL, NULL);
check_gsserr("gss_inquire_cred", major, minor);
display_canon_name("Target name", target_name, &mech_krb5);
mech = use_spnego ? &mech_spnego : &mech_krb5;
display_oid("Target mech", mech);
flags = GSS_C_REPLAY_FLAG | GSS_C_SEQUENCE_FLAG;
establish_contexts(mech, claimant_cred_handle, verifier_cred_handle,
target_name, flags, &initiator_context,
&acceptor_context, &source_name, NULL,
deleg_cred_handle);
test_prf(initiator_context, acceptor_context, GSS_C_PRF_KEY_FULL);
test_prf(initiator_context, acceptor_context, GSS_C_PRF_KEY_PARTIAL);
(void)gss_release_name(&minor, &source_name);
(void)gss_delete_sec_context(&minor, &acceptor_context, NULL);
(void)gss_delete_sec_context(&minor, &initiator_context, NULL);
}
static void
get_default_cred(const char *keytab_name, gss_OID_set mechs,
gss_cred_id_t *impersonator_cred_handle)
{
OM_uint32 major = GSS_S_FAILURE, minor;
krb5_error_code ret;
krb5_context context = NULL;
krb5_keytab keytab = NULL;
krb5_principal keytab_principal = NULL;
krb5_ccache ccache = NULL;
if (keytab_name != NULL) {
ret = krb5_init_context(&context);
check_k5err(context, "krb5_init_context", ret);
ret = krb5_kt_resolve(context, keytab_name, &keytab);
check_k5err(context, "krb5_kt_resolve", ret);
ret = krb5_cc_default(context, &ccache);
check_k5err(context, "krb5_cc_default", ret);
ret = krb5_cc_get_principal(context, ccache, &keytab_principal);
check_k5err(context, "krb5_cc_get_principal", ret);
major = gss_krb5_import_cred(&minor, ccache, keytab_principal, keytab,
impersonator_cred_handle);
check_gsserr("gss_krb5_import_cred", major, minor);
krb5_free_principal(context, keytab_principal);
krb5_cc_close(context, ccache);
krb5_kt_close(context, keytab);
krb5_free_context(context);
} else {
major = gss_acquire_cred(&minor, GSS_C_NO_NAME, GSS_C_INDEFINITE,
mechs, GSS_C_BOTH, impersonator_cred_handle,
NULL, NULL);
check_gsserr("gss_acquire_cred", major, minor);
}
}
int
main(int argc, char *argv[])
{
OM_uint32 minor, major;
gss_cred_id_t impersonator_cred_handle = GSS_C_NO_CREDENTIAL;
gss_cred_id_t user_cred_handle = GSS_C_NO_CREDENTIAL;
gss_cred_id_t delegated_cred_handle = GSS_C_NO_CREDENTIAL;
gss_name_t user = GSS_C_NO_NAME, target = GSS_C_NO_NAME;
gss_OID_set mechs, actual_mechs = GSS_C_NO_OID_SET;
uid_t uid;
if (argc < 2 || argc > 5) {
fprintf(stderr, "Usage: %s [--spnego] [user] "
"[proxy-target] [keytab]\n", argv[0]);
fprintf(stderr, " proxy-target and keytab are optional\n");
exit(1);
}
if (strcmp(argv[1], "--spnego") == 0) {
use_spnego++;
argc--;
argv++;
}
user = import_name(argv[1]);
major = gss_pname_to_uid(&minor, user, NULL, &uid);
check_gsserr("gss_pname_to_uid(user)", major, minor);
if (argc > 2 && strcmp(argv[2], "-") != 0)
target = import_name(argv[2]);
mechs = use_spnego ? &mechset_spnego : &mechset_krb5;
get_default_cred((argc > 3) ? argv[3] : NULL, mechs,
&impersonator_cred_handle);
printf("Protocol transition tests follow\n");
printf("-----------------------------------\n\n");
/* get S4U2Self cred */
major = gss_acquire_cred_impersonate_name(&minor, impersonator_cred_handle,
user, GSS_C_INDEFINITE, mechs,
GSS_C_INITIATE,
&user_cred_handle, &actual_mechs,
NULL);
check_gsserr("gss_acquire_cred_impersonate_name", major, minor);
/* Try to store it in default ccache */
major = gss_store_cred(&minor, user_cred_handle, GSS_C_INITIATE,
&mechs->elements[0], 1, 1, NULL, NULL);
check_gsserr("gss_store_cred", major, minor);
init_accept_sec_context(user_cred_handle, impersonator_cred_handle,
&delegated_cred_handle);
printf("\n");
(void)gss_release_name(&minor, &user);
(void)gss_release_name(&minor, &target);
(void)gss_release_cred(&minor, &delegated_cred_handle);
(void)gss_release_cred(&minor, &impersonator_cred_handle);
(void)gss_release_cred(&minor, &user_cred_handle);
(void)gss_release_oid_set(&minor, &actual_mechs);
return 0;
}
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