/* -*- mode: c; indent-tabs-mode: nil -*- */

/* tests/gssapi/t_s4u2proxy_deleg.c - Test S4U2Proxy after krb5 auth */

/*

 * Copyright 2011 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"

/*

 * Usage: ./t_s4u2proxy_krb5 [--spnego] client_cache storage_cache

 *                                      [accname|-] service1 service2

 *

 * This program performs a regular Kerberos or SPNEGO authentication from the

 * default principal of client_cache to service1.  If that authentication

 * yields delegated credentials, the program stores those credentials in

 * sorage_ccache and uses that cache to perform a second authentication to

 * service2 using S4U2Proxy.

 *

 * The default keytab must contain keys for service1 and service2.  The default

 * ccache must contain a TGT for service1.  This program assumes that krb5 or

 * SPNEGO authentication requires only one token exchange.

 */

int

main(int argc, char *argv[])

{

    const char *client_ccname, *storage_ccname, *accname, *service1, *service2;

    krb5_context context = NULL;

    krb5_error_code ret;

    krb5_boolean use_spnego = FALSE;

    krb5_ccache storage_ccache = NULL;

    krb5_principal client_princ = NULL;

    OM_uint32 minor, major, flags;

    gss_buffer_desc buf = GSS_C_EMPTY_BUFFER;

    gss_OID mech;

    gss_OID_set mechs;

    gss_name_t acceptor_name = GSS_C_NO_NAME, client_name = GSS_C_NO_NAME;

    gss_name_t service1_name = GSS_C_NO_NAME, service2_name = GSS_C_NO_NAME;

    gss_cred_id_t service1_cred = GSS_C_NO_CREDENTIAL;

    gss_cred_id_t deleg_cred = GSS_C_NO_CREDENTIAL;

    gss_ctx_id_t initiator_context, acceptor_context;

    /* Parse arguments. */

    if (argc >= 2 && strcmp(argv[1], "--spnego") == 0) {

        use_spnego = TRUE;

        argc--;

        argv++;

    }

    if (argc != 6) {

        fprintf(stderr, "./t_s4u2proxy_krb5 [--spnego] client_ccache "

                "storage_ccache [accname|-] service1 service2\n");

        return 1;

    }

    client_ccname = argv[1];

    storage_ccname = argv[2];

    accname = argv[3];

    service1 = argv[4];

    service2 = argv[5];

    mech = use_spnego ? &mech_spnego : &mech_krb5;

    mechs = use_spnego ? &mechset_spnego : &mechset_krb5;

    ret = krb5_init_context(&context);

    check_k5err(context, "krb5_init_context", ret);

    /* Get GSS_C_BOTH acceptor credentials, using the default ccache. */

    acceptor_name = GSS_C_NO_NAME;

    if (strcmp(accname, "-") != 0)

        acceptor_name = import_name(service1);

    major = gss_acquire_cred(&minor, acceptor_name, GSS_C_INDEFINITE,

                             mechs, GSS_C_BOTH, &service1_cred, NULL, NULL);

    check_gsserr("gss_acquire_cred(service1)", major, minor);

    /* Establish contexts using the client ccache. */

    service1_name = import_name(service1);

    major = gss_krb5_ccache_name(&minor, client_ccname, NULL);

    check_gsserr("gss_krb5_ccache_name(1)", major, minor);

    flags = GSS_C_REPLAY_FLAG | GSS_C_SEQUENCE_FLAG;

    establish_contexts(mech, GSS_C_NO_CREDENTIAL, service1_cred, service1_name,

                       flags, &initiator_context, &acceptor_context,

                       &client_name, NULL, &deleg_cred);

    /* Display and remember the client principal. */

    major = gss_display_name(&minor, client_name, &buf, NULL);

    check_gsserr("gss_display_name(1)", major, minor);

    printf("auth1: %.*s\n", (int)buf.length, (char *)buf.value);

    /* Assumes buffer is null-terminated, which in our implementation it is. */

    ret = krb5_parse_name(context, buf.value, &client_princ);

    check_k5err(context, "krb5_parse_name", ret);

    (void)gss_release_buffer(&minor, &buf;;

    if (deleg_cred == GSS_C_NO_CREDENTIAL) {

        printf("no credential delegated.\n");

        goto cleanup;

    }

    /* Take the opportunity to test cred export/import on the synthesized

     * S4U2Proxy delegated cred. */

    export_import_cred(&deleg_cred);

    /* Store the delegated credentials. */

    ret = krb5_cc_resolve(context, storage_ccname, &storage_ccache);

    check_k5err(context, "krb5_cc_resolve", ret);

    ret = krb5_cc_initialize(context, storage_ccache, client_princ);

    check_k5err(context, "krb5_cc_initialize", ret);

    major = gss_krb5_copy_ccache(&minor, deleg_cred, storage_ccache);

    check_gsserr("gss_krb5_copy_ccache", major, minor);

    ret = krb5_cc_close(context, storage_ccache);

    check_k5err(context, "krb5_cc_close", ret);

    (void)gss_delete_sec_context(&minor, &initiator_context, GSS_C_NO_BUFFER);

    (void)gss_delete_sec_context(&minor, &acceptor_context, GSS_C_NO_BUFFER);

    (void)gss_release_name(&minor, &client_name);

    (void)gss_release_cred(&minor, &deleg_cred);

    /* Establish contexts using the storage ccache. */

    service2_name = import_name(service2);

    major = gss_krb5_ccache_name(&minor, storage_ccname, NULL);

    check_gsserr("gss_krb5_ccache_name(2)", major, minor);

    establish_contexts(mech, GSS_C_NO_CREDENTIAL, GSS_C_NO_CREDENTIAL,

                       service2_name, flags, &initiator_context,

                       &acceptor_context, &client_name, NULL, &deleg_cred);

    major = gss_display_name(&minor, client_name, &buf, NULL);

    check_gsserr("gss_display_name(2)", major, minor);

    printf("auth2: %.*s\n", (int)buf.length, (char *)buf.value);

    (void)gss_release_buffer(&minor, &buf;;

cleanup:

    (void)gss_release_name(&minor, &acceptor_name);

    (void)gss_release_name(&minor, &client_name);

    (void)gss_release_name(&minor, &service1_name);

    (void)gss_release_name(&minor, &service2_name);

    (void)gss_release_cred(&minor, &service1_cred);

    (void)gss_release_cred(&minor, &deleg_cred);

    (void)gss_delete_sec_context(&minor, &initiator_context, GSS_C_NO_BUFFER);

    (void)gss_delete_sec_context(&minor, &acceptor_context, GSS_C_NO_BUFFER);

    krb5_free_principal(context, client_princ);

    krb5_free_context(context);

    return 0;

}