/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */ /* kdc/do_tgs_req.c - KDC Routines to deal with TGS_REQ's */ /* * Copyright 1990, 1991, 2001, 2007, 2008, 2009, 2013, 2014 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. */ /* * Copyright (c) 2006-2008, Novell, Inc. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * The copyright holder's name is not used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include "k5-int.h" #include #ifdef HAVE_NETINET_IN_H #include #include #ifndef hpux #include #endif #endif #include "kdc_util.h" #include "kdc_audit.h" #include "policy.h" #include "extern.h" #include "adm_proto.h" #include static krb5_error_code find_alternate_tgs(kdc_realm_t *, krb5_principal, krb5_db_entry **, const char**); static krb5_error_code prepare_error_tgs(struct kdc_request_state *, krb5_kdc_req *,krb5_ticket *,int, krb5_principal,krb5_data **,const char *, krb5_pa_data **); static krb5_error_code decrypt_2ndtkt(kdc_realm_t *, krb5_kdc_req *, krb5_flags, const krb5_ticket **, krb5_db_entry **, krb5_keyblock **, const char **); static krb5_error_code gen_session_key(kdc_realm_t *, krb5_kdc_req *, krb5_db_entry *, krb5_keyblock *, const char **); static krb5_int32 find_referral_tgs(kdc_realm_t *, krb5_kdc_req *, krb5_principal *); static krb5_error_code db_get_svc_princ(krb5_context, krb5_principal, krb5_flags, krb5_db_entry **, const char **); static krb5_error_code search_sprinc(kdc_realm_t *, krb5_kdc_req *, krb5_flags, krb5_db_entry **, const char **); /*ARGSUSED*/ krb5_error_code process_tgs_req(krb5_kdc_req *request, krb5_data *pkt, const krb5_fulladdr *from, kdc_realm_t *kdc_active_realm, krb5_data **response) { krb5_keyblock * subkey = 0; krb5_keyblock *header_key = NULL; krb5_keyblock *stkt_server_key = NULL; krb5_keyblock *subject_key; krb5_db_entry *server = NULL; krb5_db_entry *stkt_server = NULL; krb5_db_entry *subject_server; krb5_kdc_rep reply; krb5_enc_kdc_rep_part reply_encpart; krb5_ticket ticket_reply, *header_ticket = 0; const krb5_ticket *stkt = NULL; krb5_enc_tkt_part enc_tkt_reply; int newtransited = 0; krb5_error_code retval = 0; krb5_keyblock server_keyblock, *encrypting_key; krb5_timestamp kdc_time, authtime = 0; krb5_keyblock session_key, local_tgt_key; krb5_keyblock *reply_key = NULL; krb5_principal cprinc = NULL, sprinc = NULL, altcprinc = NULL; krb5_const_principal authdata_client; krb5_principal stkt_authdata_client = NULL; krb5_last_req_entry *nolrarray[2], nolrentry; int errcode; const char *status = 0; krb5_enc_tkt_part *header_enc_tkt = NULL; /* TGT */ krb5_enc_tkt_part *subject_tkt = NULL; /* TGT or evidence ticket */ krb5_db_entry *client = NULL, *header_server = NULL; krb5_db_entry *local_tgt, *local_tgt_storage = NULL; krb5_pa_s4u_x509_user *s4u_x509_user = NULL; /* protocol transition request */ krb5_authdata **kdc_issued_auth_data = NULL; /* auth data issued by KDC */ unsigned int c_flags = 0, s_flags = 0; /* client/server KDB flags */ krb5_boolean is_referral, is_crossrealm; const char *emsg = NULL; krb5_kvno ticket_kvno = 0; struct kdc_request_state *state = NULL; krb5_pa_data *pa_tgs_req; /*points into request*/ krb5_data scratch; krb5_pa_data **e_data = NULL; krb5_audit_state *au_state = NULL; krb5_data **auth_indicators = NULL; void *ad_info = NULL, *stkt_ad_info = NULL; memset(&reply, 0, sizeof(reply)); memset(&reply_encpart, 0, sizeof(reply_encpart)); memset(&ticket_reply, 0, sizeof(ticket_reply)); memset(&enc_tkt_reply, 0, sizeof(enc_tkt_reply)); memset(&server_keyblock, 0, sizeof(server_keyblock)); memset(&local_tgt_key, 0, sizeof(local_tgt_key)); session_key.contents = NULL; /* Save pointer to client-requested service principal, in case of * errors before a successful call to search_sprinc(). */ sprinc = request->server; if (request->msg_type != KRB5_TGS_REQ) { krb5_free_kdc_req(kdc_context, request); return KRB5_BADMSGTYPE; } errcode = kdc_make_rstate(kdc_active_realm, &state); if (errcode !=0) { krb5_free_kdc_req(kdc_context, request); return errcode; } /* Initialize audit state. */ errcode = kau_init_kdc_req(kdc_context, request, from, &au_state); if (errcode) { krb5_free_kdc_req(kdc_context, request); return errcode; } /* Seed the audit trail with the request ID and basic information. */ kau_tgs_req(kdc_context, TRUE, au_state); errcode = kdc_process_tgs_req(kdc_active_realm, request, from, pkt, &header_ticket, &header_server, &header_key, &subkey, &pa_tgs_req); if (header_ticket && header_ticket->enc_part2) cprinc = header_ticket->enc_part2->client; if (errcode) { status = "PROCESS_TGS"; goto cleanup; } if (!header_ticket) { errcode = KRB5_NO_TKT_SUPPLIED; /* XXX? */ goto cleanup; } errcode = kau_make_tkt_id(kdc_context, header_ticket, &au_state->tkt_in_id); if (errcode) goto cleanup; scratch.length = pa_tgs_req->length; scratch.data = (char *) pa_tgs_req->contents; errcode = kdc_find_fast(&request, &scratch, subkey, header_ticket->enc_part2->session, state, NULL); /* Reset sprinc because kdc_find_fast() can replace request. */ sprinc = request->server; if (errcode !=0) { status = "FIND_FAST"; goto cleanup; } errcode = get_local_tgt(kdc_context, &sprinc->realm, header_server, &local_tgt, &local_tgt_storage, &local_tgt_key); if (errcode) { status = "GET_LOCAL_TGT"; goto cleanup; } /* Ignore (for now) the request modification due to FAST processing. */ au_state->request = request; /* * Pointer to the encrypted part of the header ticket, which may be * replaced to point to the encrypted part of the evidence ticket * if constrained delegation is used. This simplifies the number of * special cases for constrained delegation. */ header_enc_tkt = header_ticket->enc_part2; /* * We've already dealt with the AP_REQ authentication, so we can * use header_ticket freely. The encrypted part (if any) has been * decrypted with the session key. */ au_state->stage = SRVC_PRINC; /* XXX make sure server here has the proper realm...taken from AP_REQ header? */ if (isflagset(request->kdc_options, KDC_OPT_CANONICALIZE)) { setflag(c_flags, KRB5_KDB_FLAG_CANONICALIZE); setflag(s_flags, KRB5_KDB_FLAG_CANONICALIZE); } errcode = search_sprinc(kdc_active_realm, request, s_flags, &server, &status); if (errcode != 0) goto cleanup; sprinc = server->princ; /* If we got a cross-realm TGS which is not the requested server, we are * issuing a referral (or alternate TGT, which we treat similarly). */ is_referral = is_cross_tgs_principal(server->princ) && !krb5_principal_compare(kdc_context, request->server, server->princ); au_state->stage = VALIDATE_POL; if ((errcode = krb5_timeofday(kdc_context, &kdc_time))) goto cleanup; is_crossrealm = !data_eq(header_server->princ->realm, sprinc->realm); if (is_crossrealm) setflag(c_flags, KRB5_KDB_FLAG_CROSS_REALM); if (is_referral) setflag(c_flags, KRB5_KDB_FLAG_ISSUING_REFERRAL); /* Check for protocol transition */ errcode = kdc_process_s4u2self_req(kdc_active_realm, request, server, subkey, header_enc_tkt->session, &s4u_x509_user, &client, &status); if (s4u_x509_user != NULL || errcode != 0) { if (s4u_x509_user != NULL) au_state->s4u2self_user = s4u_x509_user->user_id.user; au_state->status = status; kau_s4u2self(kdc_context, errcode ? FALSE : TRUE, au_state); au_state->s4u2self_user = NULL; } /* For user-to-user and S4U2Proxy requests, decrypt the second ticket. */ errcode = decrypt_2ndtkt(kdc_active_realm, request, c_flags, &stkt, &stkt_server, &stkt_server_key, &status); if (errcode) goto cleanup; retval = validate_tgs_request(kdc_active_realm, request, server, header_ticket, stkt, stkt_server, kdc_time, s4u_x509_user, client, is_crossrealm, is_referral, &status, &e_data); if (retval) { if (retval == KDC_ERR_POLICY || retval == KDC_ERR_BADOPTION) au_state->violation = PROT_CONSTRAINT; errcode = retval + ERROR_TABLE_BASE_krb5; goto cleanup; } if (errcode) goto cleanup; if (s4u_x509_user != NULL && client == NULL) { /* * For an S4U2Self referral request (the requesting service is * following a referral back to its own realm), the authdata in the * header ticket should be for the requested client. */ setflag(c_flags, KRB5_KDB_FLAG_PROTOCOL_TRANSITION); authdata_client = s4u_x509_user->user_id.user; } else { /* Otherwise (including for initial S4U2Self requests), the authdata * should be for the header ticket client. */ authdata_client = header_enc_tkt->client; } errcode = krb5_db_get_authdata_info(kdc_context, c_flags, header_enc_tkt->authorization_data, authdata_client, request->server, header_key, &local_tgt_key, local_tgt, header_enc_tkt->times.authtime, &ad_info, NULL); if (errcode && errcode != KRB5_PLUGIN_OP_NOTSUPP) goto cleanup; /* Flag all S4U2Self requests now that we have checked the authdata. */ if (s4u_x509_user != NULL) setflag(c_flags, KRB5_KDB_FLAG_PROTOCOL_TRANSITION); if (isflagset(request->kdc_options, KDC_OPT_CNAME_IN_ADDL_TKT)) { /* Do constrained delegation protocol and authorization checks. */ setflag(c_flags, KRB5_KDB_FLAG_CONSTRAINED_DELEGATION); errcode = kdc_process_s4u2proxy_req(kdc_active_realm, c_flags, request, stkt->enc_part2, local_tgt, &local_tgt_key, stkt_server, stkt_server_key, header_ticket->enc_part2->client, server, request->server, ad_info, &stkt_ad_info, &stkt_authdata_client, &status); if (errcode == KDC_ERR_POLICY || errcode == KDC_ERR_BADOPTION) au_state->violation = PROT_CONSTRAINT; else if (errcode) au_state->violation = LOCAL_POLICY; au_state->status = status; retval = kau_make_tkt_id(kdc_context, stkt, &au_state->evid_tkt_id); if (retval) { errcode = retval; goto cleanup; } kau_s4u2proxy(kdc_context, errcode ? FALSE : TRUE, au_state); if (errcode) goto cleanup; assert(krb5_is_tgs_principal(header_ticket->server)); /* Use the parsed authdata from the second ticket during authdata * handling. */ krb5_db_free_authdata_info(kdc_context, ad_info); ad_info = stkt_ad_info; stkt_ad_info = NULL; } au_state->stage = ISSUE_TKT; errcode = gen_session_key(kdc_active_realm, request, server, &session_key, &status); if (errcode) goto cleanup; /* * subject_tkt will refer to the evidence ticket (for constrained * delegation) or the TGT. The distinction from header_enc_tkt is * necessary because the TGS signature only protects some fields: * the others could be forged by a malicious server. */ if (isflagset(c_flags, KRB5_KDB_FLAG_CONSTRAINED_DELEGATION)) { subject_tkt = stkt->enc_part2; subject_server = stkt_server; subject_key = stkt_server_key; } else { subject_tkt = header_enc_tkt; subject_server = header_server; subject_key = header_key; } authtime = subject_tkt->times.authtime; /* Extract and check auth indicators from the subject ticket, except for * S4U2Self requests (where the client didn't authenticate). */ if (s4u_x509_user == NULL) { errcode = get_auth_indicators(kdc_context, subject_tkt, local_tgt, &local_tgt_key, &auth_indicators); if (errcode) { status = "GET_AUTH_INDICATORS"; goto cleanup; } errcode = check_indicators(kdc_context, server, auth_indicators); if (errcode) { status = "HIGHER_AUTHENTICATION_REQUIRED"; goto cleanup; } } if (is_referral) ticket_reply.server = server->princ; else ticket_reply.server = request->server; /* XXX careful for realm... */ enc_tkt_reply.flags = get_ticket_flags(request->kdc_options, client, server, header_enc_tkt); enc_tkt_reply.times.starttime = 0; /* OK_TO_AUTH_AS_DELEGATE must be set on the service requesting S4U2Self * for forwardable tickets to be issued. */ if (isflagset(c_flags, KRB5_KDB_FLAG_PROTOCOL_TRANSITION) && !is_referral && !isflagset(server->attributes, KRB5_KDB_OK_TO_AUTH_AS_DELEGATE)) clear(enc_tkt_reply.flags, TKT_FLG_FORWARDABLE); /* don't use new addresses unless forwarded, see below */ enc_tkt_reply.caddrs = header_enc_tkt->caddrs; /* noaddrarray[0] = 0; */ reply_encpart.caddrs = 0;/* optional...don't put it in */ reply_encpart.enc_padata = NULL; /* * It should be noted that local policy may affect the * processing of any of these flags. For example, some * realms may refuse to issue renewable tickets */ if (isflagset(request->kdc_options, KDC_OPT_FORWARDED) || isflagset(request->kdc_options, KDC_OPT_PROXY)) { /* include new addresses in ticket & reply */ enc_tkt_reply.caddrs = request->addresses; reply_encpart.caddrs = request->addresses; } if (isflagset(request->kdc_options, KDC_OPT_POSTDATED)) enc_tkt_reply.times.starttime = request->from; else enc_tkt_reply.times.starttime = kdc_time; if (isflagset(request->kdc_options, KDC_OPT_VALIDATE)) { assert(isflagset(c_flags, KRB5_KDB_FLAGS_S4U) == 0); /* BEWARE of allocation hanging off of ticket & enc_part2, it belongs to the caller */ ticket_reply = *(header_ticket); enc_tkt_reply = *(header_ticket->enc_part2); enc_tkt_reply.authorization_data = NULL; clear(enc_tkt_reply.flags, TKT_FLG_INVALID); } if (isflagset(request->kdc_options, KDC_OPT_RENEW)) { krb5_timestamp old_starttime; krb5_deltat old_life; assert(isflagset(c_flags, KRB5_KDB_FLAGS_S4U) == 0); /* BEWARE of allocation hanging off of ticket & enc_part2, it belongs to the caller */ ticket_reply = *(header_ticket); enc_tkt_reply = *(header_ticket->enc_part2); enc_tkt_reply.authorization_data = NULL; old_starttime = enc_tkt_reply.times.starttime ? enc_tkt_reply.times.starttime : enc_tkt_reply.times.authtime; old_life = ts_delta(enc_tkt_reply.times.endtime, old_starttime); enc_tkt_reply.times.starttime = kdc_time; enc_tkt_reply.times.endtime = ts_min(header_ticket->enc_part2->times.renew_till, ts_incr(kdc_time, old_life)); } else { /* not a renew request */ enc_tkt_reply.times.starttime = kdc_time; kdc_get_ticket_endtime(kdc_active_realm, enc_tkt_reply.times.starttime, header_enc_tkt->times.endtime, request->till, client, server, &enc_tkt_reply.times.endtime); } kdc_get_ticket_renewtime(kdc_active_realm, request, header_enc_tkt, client, server, &enc_tkt_reply); errcode = check_kdcpolicy_tgs(kdc_context, request, server, header_ticket, auth_indicators, kdc_time, &enc_tkt_reply.times, &status); if (errcode) goto cleanup; /* * Set authtime to be the same as header or evidence ticket's */ enc_tkt_reply.times.authtime = authtime; /* starttime is optional, and treated as authtime if not present. so we can nuke it if it matches */ if (enc_tkt_reply.times.starttime == enc_tkt_reply.times.authtime) enc_tkt_reply.times.starttime = 0; if (isflagset(c_flags, KRB5_KDB_FLAG_PROTOCOL_TRANSITION)) { altcprinc = s4u_x509_user->user_id.user; } else if (isflagset(c_flags, KRB5_KDB_FLAG_CONSTRAINED_DELEGATION)) { /* kdc_process_s4u2proxy_req() only allows cross-realm requests if * stkt_authdata_client is set. */ altcprinc = is_crossrealm ? stkt_authdata_client : subject_tkt->client; } else { altcprinc = NULL; } if (isflagset(request->kdc_options, KDC_OPT_ENC_TKT_IN_SKEY)) { encrypting_key = stkt->enc_part2->session; } else { errcode = get_first_current_key(kdc_context, server, &server_keyblock); if (errcode) { status = "FINDING_SERVER_KEY"; goto cleanup; } encrypting_key = &server_keyblock; } if (isflagset(c_flags, KRB5_KDB_FLAG_CONSTRAINED_DELEGATION)) { /* * Don't allow authorization data to be disabled if constrained * delegation is requested. We don't want to deny the server * the ability to validate that delegation was used. */ clear(server->attributes, KRB5_KDB_NO_AUTH_DATA_REQUIRED); } if (isflagset(server->attributes, KRB5_KDB_NO_AUTH_DATA_REQUIRED) == 0) { /* If we are not doing protocol transition, try to look up the subject * principal so that KDB modules can add additional authdata. */ if (!isflagset(c_flags, KRB5_KDB_FLAG_PROTOCOL_TRANSITION)) { /* Generate authorization data so we can include it in ticket */ setflag(c_flags, KRB5_KDB_FLAG_INCLUDE_PAC); /* Map principals from foreign (possibly non-AD) realms */ setflag(c_flags, KRB5_KDB_FLAG_MAP_PRINCIPALS); assert(client == NULL); /* should not have been set already */ errcode = krb5_db_get_principal(kdc_context, subject_tkt->client, c_flags, &client); } } if (isflagset(c_flags, KRB5_KDB_FLAGS_S4U) && !is_referral) enc_tkt_reply.client = altcprinc; else enc_tkt_reply.client = header_enc_tkt->client; enc_tkt_reply.session = &session_key; enc_tkt_reply.transited.tr_type = KRB5_DOMAIN_X500_COMPRESS; enc_tkt_reply.transited.tr_contents = empty_string; /* equivalent of "" */ /* * Only add the realm of the presented tgt to the transited list if * it is different than the server realm (cross-realm) and it is different * than the realm of the client (since the realm of the client is already * implicitly part of the transited list and should not be explicitly * listed). */ if (!is_crossrealm || krb5_realm_compare(kdc_context, header_ticket->server, enc_tkt_reply.client)) { /* tgt issued by local realm or issued by realm of client */ enc_tkt_reply.transited = header_enc_tkt->transited; } else { /* tgt issued by some other realm and not the realm of the client */ /* assemble new transited field into allocated storage */ if (header_enc_tkt->transited.tr_type != KRB5_DOMAIN_X500_COMPRESS) { status = "VALIDATE_TRANSIT_TYPE"; errcode = KRB5KDC_ERR_TRTYPE_NOSUPP; goto cleanup; } memset(&enc_tkt_reply.transited, 0, sizeof(enc_tkt_reply.transited)); enc_tkt_reply.transited.tr_type = KRB5_DOMAIN_X500_COMPRESS; if ((errcode = add_to_transited(&header_enc_tkt->transited.tr_contents, &enc_tkt_reply.transited.tr_contents, header_ticket->server, enc_tkt_reply.client, request->server))) { status = "ADD_TO_TRANSITED_LIST"; goto cleanup; } newtransited = 1; } if (!isflagset (request->kdc_options, KDC_OPT_DISABLE_TRANSITED_CHECK)) { errcode = kdc_check_transited_list (kdc_active_realm, &enc_tkt_reply.transited.tr_contents, krb5_princ_realm (kdc_context, header_enc_tkt->client), krb5_princ_realm (kdc_context, request->server)); if (errcode == 0) { setflag (enc_tkt_reply.flags, TKT_FLG_TRANSIT_POLICY_CHECKED); } else { log_tgs_badtrans(kdc_context, cprinc, sprinc, &enc_tkt_reply.transited.tr_contents, errcode); } } else krb5_klog_syslog(LOG_INFO, _("not checking transit path")); if (kdc_active_realm->realm_reject_bad_transit && !isflagset(enc_tkt_reply.flags, TKT_FLG_TRANSIT_POLICY_CHECKED)) { errcode = KRB5KDC_ERR_POLICY; status = "BAD_TRANSIT"; au_state->violation = LOCAL_POLICY; goto cleanup; } errcode = handle_authdata(kdc_context, c_flags, client, server, subject_server, local_tgt, &local_tgt_key, subkey != NULL ? subkey : header_ticket->enc_part2->session, encrypting_key, subject_key, pkt, request, altcprinc, ad_info, subject_tkt, &auth_indicators, &enc_tkt_reply); if (errcode) { krb5_klog_syslog(LOG_INFO, _("TGS_REQ : handle_authdata (%d)"), errcode); status = "HANDLE_AUTHDATA"; goto cleanup; } ticket_reply.enc_part2 = &enc_tkt_reply; /* If we are doing user-to-user authentication, encrypt the ticket using * the session key of the second ticket. */ if (isflagset(request->kdc_options, KDC_OPT_ENC_TKT_IN_SKEY)) { ticket_kvno = 0; ticket_reply.enc_part.enctype = stkt->enc_part2->session->enctype; kau_u2u(kdc_context, TRUE, au_state); } else { ticket_kvno = current_kvno(server); } errcode = krb5_encrypt_tkt_part(kdc_context, encrypting_key, &ticket_reply); if (errcode) goto cleanup; ticket_reply.enc_part.kvno = ticket_kvno; /* Start assembling the response */ au_state->stage = ENCR_REP; reply.msg_type = KRB5_TGS_REP; if (isflagset(c_flags, KRB5_KDB_FLAG_PROTOCOL_TRANSITION) && krb5int_find_pa_data(kdc_context, request->padata, KRB5_PADATA_S4U_X509_USER) != NULL) { errcode = kdc_make_s4u2self_rep(kdc_context, subkey, header_ticket->enc_part2->session, s4u_x509_user, &reply, &reply_encpart); if (errcode) au_state->status = status; kau_s4u2self(kdc_context, errcode ? FALSE : TRUE, au_state); if (errcode) goto cleanup; } reply.client = enc_tkt_reply.client; reply.enc_part.kvno = 0;/* We are using the session key */ reply.ticket = &ticket_reply; reply_encpart.session = &session_key; reply_encpart.nonce = request->nonce; /* copy the time fields */ reply_encpart.times = enc_tkt_reply.times; nolrentry.lr_type = KRB5_LRQ_NONE; nolrentry.value = 0; nolrentry.magic = 0; nolrarray[0] = &nolrentry; nolrarray[1] = 0; reply_encpart.last_req = nolrarray; /* not available for TGS reqs */ reply_encpart.key_exp = 0;/* ditto */ reply_encpart.flags = enc_tkt_reply.flags; reply_encpart.server = ticket_reply.server; /* use the session key in the ticket, unless there's a subsession key in the AP_REQ */ reply.enc_part.enctype = subkey ? subkey->enctype : header_ticket->enc_part2->session->enctype; errcode = kdc_fast_response_handle_padata(state, request, &reply, subkey ? subkey->enctype : header_ticket->enc_part2->session->enctype); if (errcode) goto cleanup; errcode =kdc_fast_handle_reply_key(state, subkey?subkey:header_ticket->enc_part2->session, &reply_key); if (errcode) goto cleanup; errcode = return_enc_padata(kdc_context, pkt, request, reply_key, server, &reply_encpart, is_referral && isflagset(s_flags, KRB5_KDB_FLAG_CANONICALIZE)); if (errcode) { status = "KDC_RETURN_ENC_PADATA"; goto cleanup; } errcode = kau_make_tkt_id(kdc_context, &ticket_reply, &au_state->tkt_out_id); if (errcode) goto cleanup; if (kdc_fast_hide_client(state)) reply.client = (krb5_principal)krb5_anonymous_principal(); errcode = krb5_encode_kdc_rep(kdc_context, KRB5_TGS_REP, &reply_encpart, subkey ? 1 : 0, reply_key, &reply, response); if (!errcode) status = "ISSUE"; memset(ticket_reply.enc_part.ciphertext.data, 0, ticket_reply.enc_part.ciphertext.length); free(ticket_reply.enc_part.ciphertext.data); /* these parts are left on as a courtesy from krb5_encode_kdc_rep so we can use them in raw form if needed. But, we don't... */ memset(reply.enc_part.ciphertext.data, 0, reply.enc_part.ciphertext.length); free(reply.enc_part.ciphertext.data); cleanup: if (status == NULL) status = "UNKNOWN_REASON"; krb5_free_keyblock_contents(kdc_context, &server_keyblock); if (reply_key) krb5_free_keyblock(kdc_context, reply_key); if (stkt_server_key) krb5_free_keyblock(kdc_context, stkt_server_key); if (errcode) emsg = krb5_get_error_message (kdc_context, errcode); au_state->status = status; if (!errcode) au_state->reply = &reply; kau_tgs_req(kdc_context, errcode ? FALSE : TRUE, au_state); kau_free_kdc_req(au_state); log_tgs_req(kdc_context, from, request, &reply, cprinc, sprinc, altcprinc, authtime, c_flags, status, errcode, emsg); if (errcode) { krb5_free_error_message (kdc_context, emsg); emsg = NULL; } if (errcode) { int got_err = 0; if (status == 0) { status = krb5_get_error_message (kdc_context, errcode); got_err = 1; } errcode -= ERROR_TABLE_BASE_krb5; if (errcode < 0 || errcode > KRB_ERR_MAX) errcode = KRB_ERR_GENERIC; retval = prepare_error_tgs(state, request, header_ticket, errcode, (server != NULL) ? server->princ : NULL, response, status, e_data); if (got_err) { krb5_free_error_message (kdc_context, status); status = 0; } } if (header_ticket != NULL) krb5_free_ticket(kdc_context, header_ticket); if (request != NULL) krb5_free_kdc_req(kdc_context, request); if (state) kdc_free_rstate(state); krb5_db_free_principal(kdc_context, server); krb5_db_free_principal(kdc_context, stkt_server); krb5_db_free_principal(kdc_context, header_server); krb5_db_free_principal(kdc_context, client); krb5_db_free_principal(kdc_context, local_tgt_storage); if (local_tgt_key.contents != NULL) krb5_free_keyblock_contents(kdc_context, &local_tgt_key); if (session_key.contents != NULL) krb5_free_keyblock_contents(kdc_context, &session_key); if (newtransited) free(enc_tkt_reply.transited.tr_contents.data); if (s4u_x509_user != NULL) krb5_free_pa_s4u_x509_user(kdc_context, s4u_x509_user); if (kdc_issued_auth_data != NULL) krb5_free_authdata(kdc_context, kdc_issued_auth_data); if (subkey != NULL) krb5_free_keyblock(kdc_context, subkey); if (header_key != NULL) krb5_free_keyblock(kdc_context, header_key); if (reply.padata) krb5_free_pa_data(kdc_context, reply.padata); if (reply_encpart.enc_padata) krb5_free_pa_data(kdc_context, reply_encpart.enc_padata); if (enc_tkt_reply.authorization_data != NULL) krb5_free_authdata(kdc_context, enc_tkt_reply.authorization_data); krb5_free_pa_data(kdc_context, e_data); k5_free_data_ptr_list(auth_indicators); krb5_db_free_authdata_info(kdc_context, ad_info); krb5_db_free_authdata_info(kdc_context, stkt_ad_info); krb5_free_principal(kdc_context, stkt_authdata_client); return retval; } static krb5_error_code prepare_error_tgs (struct kdc_request_state *state, krb5_kdc_req *request, krb5_ticket *ticket, int error, krb5_principal canon_server, krb5_data **response, const char *status, krb5_pa_data **e_data) { krb5_error errpkt; krb5_error_code retval = 0; krb5_data *scratch, *e_data_asn1 = NULL, *fast_edata = NULL; kdc_realm_t *kdc_active_realm = state->realm_data; errpkt.magic = KV5M_ERROR; errpkt.ctime = 0; errpkt.cusec = 0; if ((retval = krb5_us_timeofday(kdc_context, &errpkt.stime, &errpkt.susec))) return(retval); errpkt.error = error; errpkt.server = request->server; if (ticket && ticket->enc_part2) errpkt.client = ticket->enc_part2->client; else errpkt.client = NULL; errpkt.text.length = strlen(status); if (!(errpkt.text.data = strdup(status))) return ENOMEM; if (!(scratch = (krb5_data *)malloc(sizeof(*scratch)))) { free(errpkt.text.data); return ENOMEM; } if (e_data != NULL) { retval = encode_krb5_padata_sequence(e_data, &e_data_asn1); if (retval) { free(scratch); free(errpkt.text.data); return retval; } errpkt.e_data = *e_data_asn1; } else errpkt.e_data = empty_data(); retval = kdc_fast_handle_error(kdc_context, state, request, e_data, &errpkt, &fast_edata); if (retval) { free(scratch); free(errpkt.text.data); krb5_free_data(kdc_context, e_data_asn1); return retval; } if (fast_edata) errpkt.e_data = *fast_edata; if (kdc_fast_hide_client(state) && errpkt.client != NULL) errpkt.client = (krb5_principal)krb5_anonymous_principal(); retval = krb5_mk_error(kdc_context, &errpkt, scratch); free(errpkt.text.data); krb5_free_data(kdc_context, e_data_asn1); krb5_free_data(kdc_context, fast_edata); if (retval) free(scratch); else *response = scratch; return retval; } /* KDC options that require a second ticket */ #define STKT_OPTIONS (KDC_OPT_CNAME_IN_ADDL_TKT | KDC_OPT_ENC_TKT_IN_SKEY) /* * If req is a second-ticket request and a second ticket is present, decrypt * it. Set *stkt_out to an alias to the ticket with populated enc_part2. Set * *server_out to the server DB entry and *key_out to the ticket decryption * key. */ static krb5_error_code decrypt_2ndtkt(kdc_realm_t *kdc_active_realm, krb5_kdc_req *req, krb5_flags flags, const krb5_ticket **stkt_out, krb5_db_entry **server_out, krb5_keyblock **key_out, const char **status) { krb5_error_code retval; krb5_db_entry *server = NULL; krb5_keyblock *key = NULL; krb5_kvno kvno; krb5_ticket *stkt; *stkt_out = NULL; *server_out = NULL; *key_out = NULL; if (!(req->kdc_options & STKT_OPTIONS) || req->second_ticket == NULL || req->second_ticket[0] == NULL) return 0; stkt = req->second_ticket[0]; retval = kdc_get_server_key(kdc_context, stkt, flags, TRUE, &server, &key, &kvno); if (retval != 0) { *status = "2ND_TKT_SERVER"; goto cleanup; } retval = krb5_decrypt_tkt_part(kdc_context, key, stkt); if (retval != 0) { *status = "2ND_TKT_DECRYPT"; goto cleanup; } *stkt_out = stkt; *server_out = server; *key_out = key; server = NULL; key = NULL; cleanup: krb5_db_free_principal(kdc_context, server); krb5_free_keyblock(kdc_context, key); return retval; } static krb5_error_code get_2ndtkt_enctype(kdc_realm_t *kdc_active_realm, krb5_kdc_req *req, krb5_enctype *useenctype, const char **status) { krb5_enctype etype; krb5_ticket *stkt = req->second_ticket[0]; int i; etype = stkt->enc_part2->session->enctype; if (!krb5_c_valid_enctype(etype)) { *status = "BAD_ETYPE_IN_2ND_TKT"; return KRB5KDC_ERR_ETYPE_NOSUPP; } for (i = 0; i < req->nktypes; i++) { if (req->ktype[i] == etype) { *useenctype = etype; break; } } return 0; } static krb5_error_code gen_session_key(kdc_realm_t *kdc_active_realm, krb5_kdc_req *req, krb5_db_entry *server, krb5_keyblock *skey, const char **status) { krb5_error_code retval; krb5_enctype useenctype = 0; /* * Some special care needs to be taken in the user-to-user * case, since we don't know what keytypes the application server * which is doing user-to-user authentication can support. We * know that it at least must be able to support the encryption * type of the session key in the TGT, since otherwise it won't be * able to decrypt the U2U ticket! So we use that in preference * to anything else. */ if (req->kdc_options & KDC_OPT_ENC_TKT_IN_SKEY) { retval = get_2ndtkt_enctype(kdc_active_realm, req, &useenctype, status); if (retval != 0) return retval; } if (useenctype == 0) { useenctype = select_session_keytype(kdc_active_realm, server, req->nktypes, req->ktype); } if (useenctype == 0) { /* unsupported ktype */ *status = "BAD_ENCRYPTION_TYPE"; return KRB5KDC_ERR_ETYPE_NOSUPP; } return krb5_c_make_random_key(kdc_context, useenctype, skey); } /* * The request seems to be for a ticket-granting service somewhere else, * but we don't have a ticket for the final TGS. Try to give the requestor * some intermediate realm. */ static krb5_error_code find_alternate_tgs(kdc_realm_t *kdc_active_realm, krb5_principal princ, krb5_db_entry **server_ptr, const char **status) { krb5_error_code retval; krb5_principal *plist = NULL, *pl2; krb5_data tmp; krb5_db_entry *server = NULL; *server_ptr = NULL; assert(is_cross_tgs_principal(princ)); if ((retval = krb5_walk_realm_tree(kdc_context, krb5_princ_realm(kdc_context, princ), krb5_princ_component(kdc_context, princ, 1), &plist, KRB5_REALM_BRANCH_CHAR))) { goto cleanup; } /* move to the end */ for (pl2 = plist; *pl2; pl2++); /* the first entry in this array is for krbtgt/local@local, so we ignore it */ while (--pl2 > plist) { tmp = *krb5_princ_realm(kdc_context, *pl2); krb5_princ_set_realm(kdc_context, *pl2, krb5_princ_realm(kdc_context, princ)); retval = db_get_svc_princ(kdc_context, *pl2, 0, &server, status); krb5_princ_set_realm(kdc_context, *pl2, &tmp); if (retval == KRB5_KDB_NOENTRY) continue; else if (retval) goto cleanup; log_tgs_alt_tgt(kdc_context, server->princ); *server_ptr = server; server = NULL; goto cleanup; } cleanup: if (retval == 0 && *server_ptr == NULL) retval = KRB5_KDB_NOENTRY; if (retval != 0) *status = "UNKNOWN_SERVER"; krb5_free_realm_tree(kdc_context, plist); krb5_db_free_principal(kdc_context, server); return retval; } /* Return true if item is an element of the space/comma-separated list. */ static krb5_boolean in_list(const char *list, const char *item) { const char *p; int len = strlen(item); if (list == NULL) return FALSE; for (p = strstr(list, item); p != NULL; p = strstr(p + 1, item)) { if ((p == list || isspace((unsigned char)p[-1]) || p[-1] == ',') && (p[len] == '\0' || isspace((unsigned char)p[len]) || p[len] == ',')) return TRUE; } return FALSE; } /* * Check whether the request satisfies the conditions for generating a referral * TGT. The caller checks whether the hostname component looks like a FQDN. */ static krb5_boolean is_referral_req(kdc_realm_t *kdc_active_realm, krb5_kdc_req *request) { krb5_boolean ret = FALSE; char *stype = NULL; char *hostbased = kdc_active_realm->realm_hostbased; char *no_referral = kdc_active_realm->realm_no_referral; if (!(request->kdc_options & KDC_OPT_CANONICALIZE)) return FALSE; if (request->kdc_options & KDC_OPT_ENC_TKT_IN_SKEY) return FALSE; if (krb5_princ_size(kdc_context, request->server) != 2) return FALSE; stype = data2string(krb5_princ_component(kdc_context, request->server, 0)); if (stype == NULL) return FALSE; switch (krb5_princ_type(kdc_context, request->server)) { case KRB5_NT_UNKNOWN: /* Allow referrals for NT-UNKNOWN principals, if configured. */ if (!in_list(hostbased, stype) && !in_list(hostbased, "*")) goto cleanup; /* FALLTHROUGH */ case KRB5_NT_SRV_HST: case KRB5_NT_SRV_INST: /* Deny referrals for specific service types, if configured. */ if (in_list(no_referral, stype) || in_list(no_referral, "*")) goto cleanup; ret = TRUE; break; default: goto cleanup; } cleanup: free(stype); return ret; } /* * Find a remote realm TGS principal for an unknown host-based service * principal. */ static krb5_int32 find_referral_tgs(kdc_realm_t *kdc_active_realm, krb5_kdc_req *request, krb5_principal *krbtgt_princ) { krb5_error_code retval = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN; char **realms = NULL, *hostname = NULL; krb5_data srealm = request->server->realm; if (!is_referral_req(kdc_active_realm, request)) goto cleanup; hostname = data2string(krb5_princ_component(kdc_context, request->server, 1)); if (hostname == NULL) { retval = ENOMEM; goto cleanup; } /* If the hostname doesn't contain a '.', it's not a FQDN. */ if (strchr(hostname, '.') == NULL) goto cleanup; retval = krb5_get_host_realm(kdc_context, hostname, &realms); if (retval) { /* no match found */ kdc_err(kdc_context, retval, "unable to find realm of host"); goto cleanup; } /* Don't return a referral to the empty realm or the service realm. */ if (realms == NULL || realms[0] == NULL || *realms[0] == '\0' || data_eq_string(srealm, realms[0])) { retval = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN; goto cleanup; } retval = krb5_build_principal(kdc_context, krbtgt_princ, srealm.length, srealm.data, "krbtgt", realms[0], (char *)0); cleanup: krb5_free_host_realm(kdc_context, realms); free(hostname); return retval; } static krb5_error_code db_get_svc_princ(krb5_context ctx, krb5_principal princ, krb5_flags flags, krb5_db_entry **server, const char **status) { krb5_error_code ret; ret = krb5_db_get_principal(ctx, princ, flags, server); if (ret == KRB5_KDB_CANTLOCK_DB) ret = KRB5KDC_ERR_SVC_UNAVAILABLE; if (ret != 0) { *status = "LOOKING_UP_SERVER"; } return ret; } static krb5_error_code search_sprinc(kdc_realm_t *kdc_active_realm, krb5_kdc_req *req, krb5_flags flags, krb5_db_entry **server, const char **status) { krb5_error_code ret; krb5_principal princ = req->server; krb5_principal reftgs = NULL; krb5_boolean allow_referral; /* Do not allow referrals for u2u or ticket modification requests, because * the server is supposed to match an already-issued ticket. */ allow_referral = !(req->kdc_options & NO_REFERRAL_OPTION); if (!allow_referral) flags &= ~KRB5_KDB_FLAG_CANONICALIZE; ret = db_get_svc_princ(kdc_context, princ, flags, server, status); if (ret == 0 || ret != KRB5_KDB_NOENTRY || !allow_referral) goto cleanup; if (!is_cross_tgs_principal(req->server)) { ret = find_referral_tgs(kdc_active_realm, req, &reftgs); if (ret != 0) goto cleanup; ret = db_get_svc_princ(kdc_context, reftgs, flags, server, status); if (ret == 0 || ret != KRB5_KDB_NOENTRY) goto cleanup; princ = reftgs; } ret = find_alternate_tgs(kdc_active_realm, princ, server, status); cleanup: if (ret != 0 && ret != KRB5KDC_ERR_SVC_UNAVAILABLE) { ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN; if (*status == NULL) *status = "LOOKING_UP_SERVER"; } krb5_free_principal(kdc_context, reftgs); return ret; }