/*
    Authors:
        Sumit Bose <sbose@redhat.com>

    Copyright (C) 2009-2010 Red Hat

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef __SSS_KRB5_H__
#define __SSS_KRB5_H__

#include "config.h"

#include <stdbool.h>
#include <talloc.h>

#ifdef HAVE_KRB5_KRB5_H
#include <krb5/krb5.h>
#else
#include <krb5.h>
#endif

#include "util/util.h"

/* MIT Kerberos has the same hardcoded warning interval of 7 days. Due to the
 * fact that using the expiration time of a Kerberos password with LDAP
 * authentication is presumably a rare case a separate config option is not
 * necessary. */
#define KERBEROS_PWEXPIRE_WARNING_TIME (7 * 24 * 60 * 60)
#define KEYTAB_CLEAN_NAME keytab_name ? keytab_name : "default"

#if defined HAVE_KRB5_CC_CACHE_MATCH && defined HAVE_KRB5_CC_GET_FULL_NAME
#define HAVE_KRB5_DIRCACHE 1
#endif

const char * KRB5_CALLCONV sss_krb5_get_error_message (krb5_context,
                                                   krb5_error_code);

void KRB5_CALLCONV sss_krb5_free_error_message(krb5_context, const char *);

#define KRB5_DEBUG(level, errctx, krb5_error) do { \
    const char *__krb5_error_msg; \
    __krb5_error_msg = sss_krb5_get_error_message(errctx, krb5_error); \
    DEBUG(level, ("%d: [%d][%s]\n", __LINE__, krb5_error, __krb5_error_msg)); \
    sss_log(SSS_LOG_ERR, "%s", __krb5_error_msg); \
    sss_krb5_free_error_message(errctx, __krb5_error_msg); \
} while(0)

krb5_error_code KRB5_CALLCONV sss_krb5_get_init_creds_opt_alloc(
                                                 krb5_context context,
                                                 krb5_get_init_creds_opt **opt);

void KRB5_CALLCONV sss_krb5_get_init_creds_opt_free (krb5_context context,
                                                  krb5_get_init_creds_opt *opt);

void KRB5_CALLCONV sss_krb5_free_unparsed_name(krb5_context context, char *name);

krb5_error_code check_for_valid_tgt(krb5_context context,
                                    krb5_ccache ccache, const char *realm,
                                    const char *client_princ_str, bool *result);

int sss_krb5_verify_keytab(const char *principal,
                           const char *realm_str,
                           const char *keytab_name);

int sss_krb5_verify_keytab_ex(const char *principal, const char *keytab_name,
                              krb5_context context, krb5_keytab keytab);

krb5_error_code find_principal_in_keytab(krb5_context ctx,
                                         krb5_keytab keytab,
                                         const char *pattern_primary,
                                         const char *pattern_realm,
                                         krb5_principal *princ);

errno_t select_principal_from_keytab(TALLOC_CTX *mem_ctx,
                                     const char *hostname,
                                     const char *desired_realm,
                                     const char *keytab_name,
                                     char **_principal,
                                     char **_primary,
                                     char **_realm);

#ifndef HAVE_KRB5_GET_INIT_CREDS_OPT_SET_EXPIRE_CALLBACK
typedef void krb5_expire_callback_func(krb5_context context, void *data,
                                             krb5_timestamp password_expiration,
                                             krb5_timestamp account_expiration,
                                             krb5_boolean is_last_req);
#endif
krb5_error_code KRB5_CALLCONV sss_krb5_get_init_creds_opt_set_expire_callback(
                                                   krb5_context context,
                                                   krb5_get_init_creds_opt *opt,
                                                   krb5_expire_callback_func cb,
                                                   void *data);

errno_t check_fast(const char *str, bool *use_fast);

krb5_error_code KRB5_CALLCONV sss_krb5_get_init_creds_opt_set_fast_ccache_name(
                                                  krb5_context context,
                                                  krb5_get_init_creds_opt *opt,
                                                  const char *fast_ccache_name);

krb5_error_code KRB5_CALLCONV sss_krb5_get_init_creds_opt_set_fast_flags(
                                                   krb5_context context,
                                                   krb5_get_init_creds_opt *opt,
                                                   krb5_flags flags);

#if HAVE_KRB5_GET_INIT_CREDS_OPT_SET_FAST_FLAGS
#define SSS_KRB5_FAST_REQUIRED KRB5_FAST_REQUIRED
#else
#define SSS_KRB5_FAST_REQUIRED 0
#endif


#ifndef HAVE_KRB5_UNPARSE_NAME_FLAGS
#define KRB5_PRINCIPAL_UNPARSE_SHORT 0x1
#define KRB5_PRINCIPAL_UNPARSE_NO_REALM 0x2
#define KRB5_PRINCIPAL_UNPARSE_DISPLAY 0x4
#endif
krb5_error_code
sss_krb5_unparse_name_flags(krb5_context context, krb5_const_principal principal,
                            int flags, char **name);

void sss_krb5_get_init_creds_opt_set_canonicalize(krb5_get_init_creds_opt *opts,
                                                  int canonicalize);

enum sss_krb5_cc_type {
    SSS_KRB5_TYPE_FILE,
#ifdef HAVE_KRB5_DIRCACHE
    SSS_KRB5_TYPE_DIR,
#endif /* HAVE_KRB5_DIRCACHE */
    SSS_KRB5_TYPE_UNKNOWN
};

enum sss_krb5_cc_type
sss_krb5_get_type(const char *full_location);
const char *
sss_krb5_residual_by_type(const char *full_location, enum sss_krb5_cc_type type);
const char *
sss_krb5_cc_file_path(const char *full_location);
const char *
sss_krb5_residual_check_type(const char *full_location,
                             enum sss_krb5_cc_type expected_type);

/* === Compatibility routines for the Heimdal Kerberos implementation === */

void sss_krb5_princ_realm(krb5_context context, krb5_const_principal princ,
                          const char **realm, int *len);

krb5_error_code
sss_krb5_free_keytab_entry_contents(krb5_context context,
                                    krb5_keytab_entry *entry);

#ifdef HAVE_KRB5_TICKET_TIMES
typedef krb5_ticket_times sss_krb5_ticket_times;
#elif HAVE_KRB5_TIMES
typedef krb5_times sss_krb5_ticket_times;
#endif

#endif /* __SSS_KRB5_H__ */