/*
* @Description: get a kerberos5 ticket for the given service (get session key)
* @Param: time offset, time expire, and principal name
* @return: 0 if success, otherwise -1
* @refer: lib/krb5_wrap/krb5_samba.c
*/
int cli_krb5_get_ticket(){
/*step1: init encrypt type*/
/*step 2: Initializes the context structure and reads the configuration file /etc/krb5.conf.
*refer: source4/heimdal/lib/krb5/context.c*/
krb5_init_context();
/*step3: set time offset refer: source4/heimdal/lib/krb5/time.c*/
krb5_set_real_time();
/*step4: make TGS_REQ refer */
ads_krb5_mk_req();
/*step5: get session key from TGS_REP */
get_krb5_smb_session_key();
}
NTSTATUS ads_verify_ticket(TALLOC_CTX *mem_ctx,
const char *realm,
time_t time_offset,
const DATA_BLOB *ticket,
char **principal,
struct PAC_DATA **pac_data,
DATA_BLOB *ap_rep,
DATA_BLOB *session_key,
bool use_replay_cache)
{
NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
NTSTATUS pac_ret;
DATA_BLOB auth_data;
krb5_context context = NULL;
krb5_auth_context auth_context = NULL;
krb5_data packet;
krb5_ticket *tkt = NULL;
krb5_rcache rcache = NULL;
krb5_keyblock *keyblock = NULL;
time_t authtime;
krb5_error_code ret = 0;
int flags = 0;
krb5_principal host_princ = NULL;
krb5_const_principal client_principal = NULL;
char *host_princ_s = NULL;
bool auth_ok = False;
bool got_auth_data = False;
struct named_mutex *mutex = NULL;
ZERO_STRUCT(packet);
ZERO_STRUCT(auth_data);
*principal = NULL;
*pac_data = NULL;
*ap_rep = data_blob_null;
*session_key = data_blob_null;
initialize_krb5_error_table();
ret = krb5_init_context(&context);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_init_context failed (%s)\n", error_message(ret)));
return NT_STATUS_LOGON_FAILURE;
}
if (time_offset != 0) {
krb5_set_real_time(context, time(NULL) + time_offset, 0);
}
ret = krb5_set_default_realm(context, realm);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_set_default_realm failed (%s)\n", error_message(ret)));
goto out;
}
/* This whole process is far more complex than I would
like. We have to go through all this to allow us to store
the secret internally, instead of using /etc/krb5.keytab */
ret = krb5_auth_con_init(context, &auth_context);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_auth_con_init failed (%s)\n", error_message(ret)));
goto out;
}
krb5_auth_con_getflags( context, auth_context, &flags );
if ( !use_replay_cache ) {
/* Disable default use of a replay cache */
flags &= ~KRB5_AUTH_CONTEXT_DO_TIME;
krb5_auth_con_setflags( context, auth_context, flags );
}
if (asprintf(&host_princ_s, "%s$", global_myname()) == -1) {
goto out;
}
strlower_m(host_princ_s);
ret = smb_krb5_parse_name(context, host_princ_s, &host_princ);
if (ret) {
DEBUG(1,("ads_verify_ticket: smb_krb5_parse_name(%s) failed (%s)\n",
host_princ_s, error_message(ret)));
goto out;
}
if ( use_replay_cache ) {
/* Lock a mutex surrounding the replay as there is no
locking in the MIT krb5 code surrounding the replay
cache... */
mutex = grab_named_mutex(talloc_tos(), "replay cache mutex",
10);
if (mutex == NULL) {
DEBUG(1,("ads_verify_ticket: unable to protect "
"replay cache with mutex.\n"));
ret = KRB5_CC_IO;
goto out;
}
/* JRA. We must set the rcache here. This will prevent
replay attacks. */
ret = krb5_get_server_rcache(context,
krb5_princ_component(context, host_princ, 0),
&rcache);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache "
"failed (%s)\n", error_message(ret)));
goto out;
}
ret = krb5_auth_con_setrcache(context, auth_context, rcache);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache "
"failed (%s)\n", error_message(ret)));
goto out;
}
}
/* Try secrets.tdb first and fallback to the krb5.keytab if
necessary */
auth_ok = ads_secrets_verify_ticket(context, auth_context, host_princ,
ticket, &tkt, &keyblock, &ret);
if (!auth_ok &&
(ret == KRB5KRB_AP_ERR_TKT_NYV ||
ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
ret == KRB5KRB_AP_ERR_SKEW)) {
goto auth_failed;
}
if (!auth_ok && lp_use_kerberos_keytab()) {
auth_ok = ads_keytab_verify_ticket(context, auth_context,
ticket, &tkt, &keyblock, &ret);
}
if ( use_replay_cache ) {
TALLOC_FREE(mutex);
#if 0
/* Heimdal leaks here, if we fix the leak, MIT crashes */
if (rcache) {
krb5_rc_close(context, rcache);
}
#endif
}
auth_failed:
if (!auth_ok) {
DEBUG(3,("ads_verify_ticket: krb5_rd_req with auth failed (%s)\n",
error_message(ret)));
/* Try map the error return in case it's something like
* a clock skew error.
*/
sret = krb5_to_nt_status(ret);
if (NT_STATUS_IS_OK(sret) || NT_STATUS_EQUAL(sret,NT_STATUS_UNSUCCESSFUL)) {
sret = NT_STATUS_LOGON_FAILURE;
}
DEBUG(10,("ads_verify_ticket: returning error %s\n",
nt_errstr(sret) ));
goto out;
}
authtime = get_authtime_from_tkt(tkt);
client_principal = get_principal_from_tkt(tkt);
ret = krb5_mk_rep(context, auth_context, &packet);
if (ret) {
DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
error_message(ret)));
goto out;
}
*ap_rep = data_blob(packet.data, packet.length);
if (packet.data) {
kerberos_free_data_contents(context, &packet);
ZERO_STRUCT(packet);
}
get_krb5_smb_session_key(context, auth_context, session_key, True);
dump_data_pw("SMB session key (from ticket)\n", session_key->data, session_key->length);
#if 0
file_save("/tmp/ticket.dat", ticket->data, ticket->length);
#endif
/* continue when no PAC is retrieved or we couldn't decode the PAC
(like accounts that have the UF_NO_AUTH_DATA_REQUIRED flag set, or
Kerberos tickets encrypted using a DES key) - Guenther */
got_auth_data = get_auth_data_from_tkt(mem_ctx, &auth_data, tkt);
if (!got_auth_data) {
DEBUG(3,("ads_verify_ticket: did not retrieve auth data. continuing without PAC\n"));
}
if (got_auth_data) {
pac_ret = decode_pac_data(mem_ctx, &auth_data, context, keyblock, client_principal, authtime, pac_data);
if (!NT_STATUS_IS_OK(pac_ret)) {
DEBUG(3,("ads_verify_ticket: failed to decode PAC_DATA: %s\n", nt_errstr(pac_ret)));
*pac_data = NULL;
}
data_blob_free(&auth_data);
}
#if 0
#if defined(HAVE_KRB5_TKT_ENC_PART2)
/* MIT */
if (tkt->enc_part2) {
file_save("/tmp/authdata.dat",
tkt->enc_part2->authorization_data[0]->contents,
tkt->enc_part2->authorization_data[0]->length);
}
#else
/* Heimdal */
if (tkt->ticket.authorization_data) {
file_save("/tmp/authdata.dat",
tkt->ticket.authorization_data->val->ad_data.data,
tkt->ticket.authorization_data->val->ad_data.length);
}
#endif
#endif
if ((ret = smb_krb5_unparse_name(context, client_principal, principal))) {
DEBUG(3,("ads_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
error_message(ret)));
sret = NT_STATUS_LOGON_FAILURE;
goto out;
}
sret = NT_STATUS_OK;
out:
TALLOC_FREE(mutex);
if (!NT_STATUS_IS_OK(sret)) {
data_blob_free(&auth_data);
}
if (!NT_STATUS_IS_OK(sret)) {
data_blob_free(ap_rep);
}
if (host_princ) {
krb5_free_principal(context, host_princ);
}
if (keyblock) {
krb5_free_keyblock(context, keyblock);
}
if (tkt != NULL) {
krb5_free_ticket(context, tkt);
}
SAFE_FREE(host_princ_s);
if (auth_context) {
krb5_auth_con_free(context, auth_context);
}
if (context) {
krb5_free_context(context);
}
return sret;
}
/*
get a kerberos5 ticket for the given service
*/
int cli_krb5_get_ticket(const char *principal, time_t time_offset,
DATA_BLOB *ticket, DATA_BLOB *session_key_krb5,
uint32 extra_ap_opts, const char *ccname,
time_t *tgs_expire)
{
krb5_error_code retval;
krb5_data packet;
krb5_context context = NULL;
krb5_ccache ccdef = NULL;
krb5_auth_context auth_context = NULL;
krb5_enctype enc_types[] = {
#ifdef ENCTYPE_ARCFOUR_HMAC
ENCTYPE_ARCFOUR_HMAC,
#endif
ENCTYPE_DES_CBC_MD5,
ENCTYPE_DES_CBC_CRC,
ENCTYPE_NULL};
initialize_krb5_error_table();
retval = krb5_init_context(&context);
if (retval) {
DEBUG(1,("cli_krb5_get_ticket: krb5_init_context failed (%s)\n",
error_message(retval)));
goto failed;
}
if (time_offset != 0) {
krb5_set_real_time(context, time(NULL) + time_offset, 0);
}
if ((retval = krb5_cc_resolve(context, ccname ?
ccname : krb5_cc_default_name(context), &ccdef))) {
DEBUG(1,("cli_krb5_get_ticket: krb5_cc_default failed (%s)\n",
error_message(retval)));
goto failed;
}
if ((retval = krb5_set_default_tgs_ktypes(context, enc_types))) {
DEBUG(1,("cli_krb5_get_ticket: krb5_set_default_tgs_ktypes failed (%s)\n",
error_message(retval)));
goto failed;
}
if ((retval = ads_krb5_mk_req(context,
&auth_context,
AP_OPTS_USE_SUBKEY | (krb5_flags)extra_ap_opts,
principal,
ccdef, &packet,
tgs_expire))) {
goto failed;
}
get_krb5_smb_session_key(context, auth_context, session_key_krb5, False);
*ticket = data_blob(packet.data, packet.length);
kerberos_free_data_contents(context, &packet);
failed:
if ( context ) {
if (ccdef)
krb5_cc_close(context, ccdef);
if (auth_context)
krb5_auth_con_free(context, auth_context);
krb5_free_context(context);
}
return retval;
}
