/* * kdc/do_tgs_req.c * * Copyright 1990,1991 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. 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. * * * KDC Routines to deal with TGS_REQ's */ #include #include #include #include #include #include #include #include #ifdef KRB5_USE_INET #include #include #ifndef hpux #include #endif #endif #include "kdc_util.h" #include "policy.h" #include "extern.h" static void find_alternate_tgs PROTOTYPE((krb5_kdc_req *, krb5_db_entry *, krb5_boolean *, int *)); static krb5_error_code prepare_error_tgs PROTOTYPE((krb5_kdc_req *, krb5_ticket *, int, const char *, krb5_data **)); /*ARGSUSED*/ krb5_error_code process_tgs_req(pkt, from, is_secondary, response) krb5_data *pkt; const krb5_fulladdr *from; /* who sent it ? */ int is_secondary; krb5_data **response; /* filled in with a response packet */ { krb5_encrypt_block eblock; krb5_keytype second_ticket_etype = ETYPE_UNKNOWN; krb5_kdc_req *request = 0; krb5_db_entry server; krb5_kdc_rep reply; krb5_enc_kdc_rep_part reply_encpart; krb5_ticket ticket_reply, *header_ticket = 0; krb5_tkt_authent *req_authdat = 0; int st_idx = 0; krb5_enc_tkt_part enc_tkt_reply; krb5_transited enc_tkt_transited; int newtransited = 0; krb5_error_code retval = 0; int nprincs = 0; krb5_boolean more; krb5_timestamp kdc_time, authtime; krb5_keyblock *session_key = 0; krb5_timestamp until, rtime; krb5_keyblock encrypting_key; char *cname = 0, *sname = 0, *tmp = 0, *fromstring = 0; krb5_last_req_entry *nolrarray[2], nolrentry; /* krb5_address *noaddrarray[1]; */ krb5_enctype useetype; int errcode, errcode2; register int i; int firstpass = 1; char *status = 0; char secondary_ch; if (is_secondary) secondary_ch = ';'; else secondary_ch = ':'; retval = decode_krb5_tgs_req(pkt, &request); if (retval) return retval; #ifdef KRB5_USE_INET if (from->address->addrtype == ADDRTYPE_INET) fromstring = (char *) inet_ntoa(*(struct in_addr *)from->address->contents); #endif if (!fromstring) fromstring = ""; if (errcode = krb5_unparse_name(request->server, &sname)) { status = "UNPARSING SERVER"; goto cleanup; } errcode = kdc_process_tgs_req(request, from, pkt, &req_authdat); if (req_authdat) header_ticket = req_authdat->ticket; if (header_ticket && header_ticket->enc_part2 && (errcode2 = krb5_unparse_name(header_ticket->enc_part2->client, &cname))) { status = "UNPARSING CLIENT"; errcode = errcode2; goto cleanup; } if (errcode) { status = "PROCESS_TGS"; goto cleanup; } if (!header_ticket) { status="UNEXPECTED NULL in header_ticket"; goto cleanup; } /* * 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. */ authtime = header_ticket->enc_part2->times.authtime; /* XXX make sure server here has the proper realm...taken from AP_REQ header? */ nprincs = 1; if (retval = krb5_db_get_principal(request->server, &server, &nprincs, &more)) { syslog(LOG_INFO, "TGS_REQ: GET_PRINCIPAL: authtime %d, host %s, %s for %s (%s)", authtime, fromstring, cname, sname, error_message(retval)); nprincs = 0; goto cleanup; } tgt_again: if (more) { status = "NON_UNIQUE_PRINCIPAL"; errcode = KRB5KDC_ERR_PRINCIPAL_NOT_UNIQUE; goto cleanup; } else if (nprincs != 1) { /* * might be a request for a TGT for some other realm; we * should do our best to find such a TGS in this db */ if (firstpass && krb5_princ_size(request->server) == 2) { krb5_data *server_1 = krb5_princ_component(request->server, 1); krb5_data *tgs_1 = krb5_princ_component(tgs_server, 1); if (server_1->length != tgs_1->length || memcmp(server_1->data, tgs_1->data, tgs_1->length)) { krb5_db_free_principal(&server, nprincs); find_alternate_tgs(request, &server, &more, &nprincs); firstpass = 0; goto tgt_again; } } krb5_db_free_principal(&server, nprincs); status = "UNKNOWN_SERVER"; errcode = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN; goto cleanup; } if (retval = krb5_timeofday(&kdc_time)) { status = "TIME_OF_DAY"; goto cleanup; } if (retval = validate_tgs_request(request, server, header_ticket, kdc_time, &status)) { if (!status) status = "UNKNOWN_REASON"; errcode = retval + ERROR_TABLE_BASE_krb5; goto cleanup; } /* * If we are using user-to-user authentication, then the resulting * ticket has to use the same encryption system as was used to * encrypt the ticket, since that's the same encryption system * that's used for the ticket session key --- and that's what we * use to encrypt the ticket! */ if (isflagset(request->kdc_options, KDC_OPT_ENC_TKT_IN_SKEY)) second_ticket_etype = request->second_ticket[st_idx]->enc_part.etype; for (i = 0; i < request->netypes; i++) { krb5_keytype ok_keytype; if (!valid_etype(request->etype[i])) continue; if (second_ticket_etype != ETYPE_UNKNOWN && second_ticket_etype != request->etype[i]) continue; if (request->etype[i] == ETYPE_DES_CBC_MD5 && !isflagset(server.attributes, KRB5_KDB_SUPPORT_DESMD5)) continue; ok_keytype = krb5_csarray[request->etype[i]]->system->proto_keytype; if (server.key.keytype == ok_keytype || server.alt_key.keytype == ok_keytype) break; } if (i == request->netypes) { /* unsupported etype */ status = "BAD_ENCRYPTION_TYPE"; errcode = KRB5KDC_ERR_ETYPE_NOSUPP; goto cleanup; } useetype = request->etype[i]; krb5_use_keytype(&eblock, useetype); retval = krb5_random_key(&eblock, krb5_csarray[useetype]->random_sequence, &session_key); if (retval) { /* random key failed */ status = "RANDOM_KEY_FAILED"; goto cleanup; } ticket_reply.server = request->server; /* XXX careful for realm... */ enc_tkt_reply.flags = 0; enc_tkt_reply.times.starttime = 0; /* * Fix header_ticket's starttime; if it's zero, fill in the * authtime's value. */ if (!(header_ticket->enc_part2->times.starttime)) header_ticket->enc_part2->times.starttime = header_ticket->enc_part2->times.authtime; /* don't use new addresses unless forwarded, see below */ enc_tkt_reply.caddrs = header_ticket->enc_part2->caddrs; /* noaddrarray[0] = 0; */ reply_encpart.caddrs = 0; /* optional...don't put it in */ /* 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_FORWARDABLE)) setflag(enc_tkt_reply.flags, TKT_FLG_FORWARDABLE); if (isflagset(request->kdc_options, KDC_OPT_FORWARDED)) { setflag(enc_tkt_reply.flags, TKT_FLG_FORWARDED); /* include new addresses in ticket & reply */ enc_tkt_reply.caddrs = request->addresses; reply_encpart.caddrs = request->addresses; } if (isflagset(header_ticket->enc_part2->flags, TKT_FLG_FORWARDED)) setflag(enc_tkt_reply.flags, TKT_FLG_FORWARDED); if (isflagset(request->kdc_options, KDC_OPT_PROXIABLE)) setflag(enc_tkt_reply.flags, TKT_FLG_PROXIABLE); if (isflagset(request->kdc_options, KDC_OPT_PROXY)) { setflag(enc_tkt_reply.flags, TKT_FLG_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_ALLOW_POSTDATE)) setflag(enc_tkt_reply.flags, TKT_FLG_MAY_POSTDATE); if (isflagset(request->kdc_options, KDC_OPT_POSTDATED)) { setflag(enc_tkt_reply.flags, TKT_FLG_POSTDATED); setflag(enc_tkt_reply.flags, TKT_FLG_INVALID); enc_tkt_reply.times.starttime = request->from; } else enc_tkt_reply.times.starttime = kdc_time; if (isflagset(request->kdc_options, KDC_OPT_VALIDATE)) { /* 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); clear(enc_tkt_reply.flags, TKT_FLG_INVALID); } if (isflagset(request->kdc_options, KDC_OPT_RENEW)) { krb5_deltat old_life; /* 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); old_life = enc_tkt_reply.times.endtime - enc_tkt_reply.times.starttime; enc_tkt_reply.times.starttime = kdc_time; enc_tkt_reply.times.endtime = min(header_ticket->enc_part2->times.renew_till, kdc_time + old_life); } else { /* not a renew request */ enc_tkt_reply.times.starttime = kdc_time; until = (request->till == 0) ? kdc_infinity : request->till; enc_tkt_reply.times.endtime = min(until, min(enc_tkt_reply.times.starttime + server.max_life, min(enc_tkt_reply.times.starttime + max_life_for_realm, header_ticket->enc_part2->times.endtime))); if (isflagset(request->kdc_options, KDC_OPT_RENEWABLE_OK) && (enc_tkt_reply.times.endtime < request->till) && isflagset(header_ticket->enc_part2->flags, TKT_FLG_RENEWABLE)) { setflag(request->kdc_options, KDC_OPT_RENEWABLE); request->rtime = min(request->till, header_ticket->enc_part2->times.renew_till); } } rtime = (request->rtime == 0) ? kdc_infinity : request->rtime; if (isflagset(request->kdc_options, KDC_OPT_RENEWABLE)) { /* already checked above in policy check to reject request for a renewable ticket using a non-renewable ticket */ setflag(enc_tkt_reply.flags, TKT_FLG_RENEWABLE); enc_tkt_reply.times.renew_till = min(rtime, min(header_ticket->enc_part2->times.renew_till, enc_tkt_reply.times.starttime + min(server.max_renewable_life, max_renewable_life_for_realm))); } else { enc_tkt_reply.times.renew_till = 0; } /* * Set authtime to be the same as header_ticket's */ enc_tkt_reply.times.authtime = header_ticket->enc_part2->times.authtime; /* * Propagate the preauthentication flags through to the returned ticket. */ if (isflagset(header_ticket->enc_part2->flags, TKT_FLG_PRE_AUTH)) setflag(enc_tkt_reply.flags, TKT_FLG_PRE_AUTH); if (isflagset(header_ticket->enc_part2->flags, TKT_FLG_HW_AUTH)) setflag(enc_tkt_reply.flags, TKT_FLG_HW_AUTH); /* 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; /* assemble any authorization data */ if (request->authorization_data.ciphertext.data) { krb5_encrypt_block eblock; krb5_data scratch; /* decrypt the authdata in the request */ if (!valid_etype(request->authorization_data.etype)) { status = "BAD_AUTH_ETYPE"; errcode = KRB5KDC_ERR_ETYPE_NOSUPP; goto cleanup; } /* put together an eblock for this encryption */ krb5_use_cstype(&eblock, request->authorization_data.etype); scratch.length = request->authorization_data.ciphertext.length; if (!(scratch.data = malloc(request->authorization_data.ciphertext.length))) { status = "AUTH_NOMEM"; goto cleanup; } /* do any necessary key pre-processing */ if (retval = krb5_process_key(&eblock, header_ticket->enc_part2->session)) { status = "AUTH_PROCESS_KEY"; free(scratch.data); goto cleanup; } /* call the encryption routine */ if (retval = krb5_decrypt((krb5_pointer) request->authorization_data.ciphertext.data, (krb5_pointer) scratch.data, scratch.length, &eblock, 0)) { status = "AUTH_ENCRYPT_FAIL"; (void) krb5_finish_key(&eblock); free(scratch.data); goto cleanup; } if (retval = krb5_finish_key(&eblock)) { status = "AUTH_FINISH_KEY"; free(scratch.data); goto cleanup; } /* scratch now has the authorization data, so we decode it */ #ifdef KRB5_USE_ISODE retval = decode_krb5_authdata(&scratch, request->unenc_authdata); #else retval = decode_krb5_authdata(&scratch, &(request->unenc_authdata)); #endif free(scratch.data); if (retval) { status = "AUTH_DECODE"; goto cleanup; } if (retval = concat_authorization_data(request->unenc_authdata, header_ticket->enc_part2->authorization_data, &enc_tkt_reply.authorization_data)) { status = "CONCAT_AUTH"; goto cleanup; } } else enc_tkt_reply.authorization_data = header_ticket->enc_part2->authorization_data; enc_tkt_reply.session = session_key; enc_tkt_reply.client = header_ticket->enc_part2->client; 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 local 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). */ /* realm compare is like strcmp, but knows how to deal with these args */ if (realm_compare(header_ticket->server, tgs_server) || realm_compare(header_ticket->server, enc_tkt_reply.client)) { /* tgt issued by local realm or issued by realm of client */ enc_tkt_reply.transited = header_ticket->enc_part2->transited; } else { /* tgt issued by some other realm and not the realm of the client */ /* assemble new transited field into allocated storage */ if (header_ticket->enc_part2->transited.tr_type != KRB5_DOMAIN_X500_COMPRESS) { status = "BAD_TRTYPE"; errcode = KRB5KDC_ERR_TRTYPE_NOSUPP; goto cleanup; } enc_tkt_transited.tr_type = KRB5_DOMAIN_X500_COMPRESS; enc_tkt_transited.tr_contents.data = 0; enc_tkt_transited.tr_contents.length = 0; enc_tkt_reply.transited = enc_tkt_transited; if (retval = add_to_transited(&header_ticket->enc_part2->transited.tr_contents, &enc_tkt_reply.transited.tr_contents, header_ticket->server, enc_tkt_reply.client, request->server)) { status = "ADD_TR_FAIL"; goto cleanup; } newtransited = 1; } ticket_reply.enc_part2 = &enc_tkt_reply; /* * If we are doing user-to-user authentication, then make sure * that the client for the second ticket matches the request * server, and then encrypt the ticket using the session key of * the second ticket. */ if (isflagset(request->kdc_options, KDC_OPT_ENC_TKT_IN_SKEY)) { krb5_keyblock *st_sealing_key; krb5_kvno st_srv_kvno; if (retval = kdc_get_server_key(request->second_ticket[st_idx], &st_sealing_key, &st_srv_kvno)) { status = "2ND_TKT_SERVER"; goto cleanup; } /* decrypt the ticket */ retval = krb5_decrypt_tkt_part(st_sealing_key, request->second_ticket[st_idx]); krb5_free_keyblock(st_sealing_key); if (retval) { status = "2ND_TKT_DECRYPT"; goto cleanup; } /* * Make sure the client for the second ticket matches * requested server. */ if (!krb5_principal_compare(request->server, request->second_ticket[st_idx]->enc_part2->client)) { if (retval = krb5_unparse_name(request->second_ticket[st_idx]->enc_part2->client, &tmp)) tmp = 0; syslog(LOG_INFO, "TGS_REQ: 2ND_TKT_MISMATCH: authtime %d, host %s, %s for %s, 2nd tkt client %s", authtime, fromstring, cname, sname, tmp ? tmp : ""); goto cleanup; } ticket_reply.enc_part.kvno = 0; ticket_reply.enc_part.etype = request->second_ticket[st_idx]->enc_part2->session->etype; krb5_use_cstype(&eblock, ticket_reply.enc_part.etype); if (retval = krb5_encrypt_tkt_part(&eblock, request->second_ticket[st_idx]->enc_part2->session, &ticket_reply)) { status = "2ND_TKT_ENCRYPT"; goto cleanup; } st_idx++; } else { /* convert server.key into a real key (it may be encrypted in the database) */ if (retval = KDB_CONVERT_KEY_OUTOF_DB(&server.key, &encrypting_key)) { status = "CONV_KEY"; goto cleanup; } ticket_reply.enc_part.kvno = server.kvno; ticket_reply.enc_part.etype = useetype; krb5_use_cstype(&eblock, ticket_reply.enc_part.etype); retval = krb5_encrypt_tkt_part(&eblock, &encrypting_key, &ticket_reply); memset((char *)encrypting_key.contents, 0, encrypting_key.length); krb5_xfree(encrypting_key.contents); if (retval) { status = "TKT_ENCRYPT"; goto cleanup; } } /* Start assembling the response */ reply.msg_type = KRB5_TGS_REP; reply.padata = 0; /* always */ reply.client = header_ticket->enc_part2->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 EXCEPT for authtime; its location is used for ktime */ reply_encpart.times = enc_tkt_reply.times; reply_encpart.times.authtime = header_ticket->enc_part2->times.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; nolrentry.lr_type = KRB5_LRQ_NONE; nolrentry.value = 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.etype = req_authdat->authenticator->subkey ? req_authdat->authenticator->subkey->etype : header_ticket->enc_part2->session->etype; krb5_use_cstype(&eblock, reply.enc_part.etype); retval = krb5_encode_kdc_rep(KRB5_TGS_REP, &reply_encpart, &eblock, req_authdat->authenticator->subkey ? req_authdat->authenticator->subkey : header_ticket->enc_part2->session, &reply, response); if (retval) { status = "ENCODE_KDC_REP"; } else { 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) syslog(LOG_INFO, "TGS_REQ%c %s: authtime %d, host %s, %s for %s%s%s", secondary_ch, status, authtime, fromstring, cname ? cname : "", sname ? sname : "", errcode ? ", " : "", errcode ? error_message(errcode) : ""); if (errcode) { errcode -= ERROR_TABLE_BASE_krb5; if (errcode < 0 || errcode > 128) errcode = KRB_ERR_GENERIC; retval = prepare_error_tgs(request, header_ticket, errcode, fromstring, response); } if (request) krb5_free_kdc_req(request); if (req_authdat) krb5_free_tkt_authent(req_authdat); if (cname) free(cname); if (sname) free(sname); if (nprincs) krb5_db_free_principal(&server, 1); if (session_key) krb5_free_keyblock(session_key); if (newtransited) free(enc_tkt_reply.transited.tr_contents.data); return retval; } static krb5_error_code prepare_error_tgs (request, ticket, error, ident, response) register krb5_kdc_req *request; krb5_ticket *ticket; int error; const char *ident; krb5_data **response; { krb5_error errpkt; krb5_error_code retval; krb5_data *scratch; errpkt.ctime = request->nonce; errpkt.cusec = 0; if (retval = krb5_us_timeofday(&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 = 0; errpkt.text.length = strlen(error_message(error+KRB5KDC_ERR_NONE))+1; if (!(errpkt.text.data = malloc(errpkt.text.length))) return ENOMEM; (void) strcpy(errpkt.text.data, error_message(error+KRB5KDC_ERR_NONE)); if (!(scratch = (krb5_data *)malloc(sizeof(*scratch)))) { free(errpkt.text.data); return ENOMEM; } errpkt.e_data.length = 0; errpkt.e_data.data = 0; retval = krb5_mk_error(&errpkt, scratch); free(errpkt.text.data); *response = scratch; return retval; } /* * 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 void find_alternate_tgs(request, server, more, nprincs) krb5_kdc_req *request; krb5_db_entry *server; krb5_boolean *more; int *nprincs; { krb5_error_code retval; krb5_principal *plist, *pl2; krb5_data tmp; *nprincs = 0; *more = FALSE; if (retval = krb5_walk_realm_tree(krb5_princ_realm(request->server), krb5_princ_component(request->server, 1), &plist, KRB5_REALM_BRANCH_CHAR)) return; /* 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) { *nprincs = 1; tmp = *krb5_princ_realm(*pl2); krb5_princ_set_realm(*pl2, krb5_princ_realm(tgs_server)); retval = krb5_db_get_principal(*pl2, server, nprincs, more); krb5_princ_set_realm(*pl2, &tmp); if (retval) { *nprincs = 0; *more = FALSE; krb5_free_realm_tree(plist); return; } if (*more) { krb5_db_free_principal(server, *nprincs); continue; } else if (*nprincs == 1) { /* Found it! */ krb5_principal tmpprinc; char *sname; tmp = *krb5_princ_realm(*pl2); krb5_princ_set_realm(*pl2, krb5_princ_realm(tgs_server)); if (retval = krb5_copy_principal(*pl2, &tmpprinc)) { krb5_db_free_principal(server, *nprincs); krb5_princ_set_realm(*pl2, &tmp); continue; } krb5_princ_set_realm(*pl2, &tmp); krb5_free_principal(request->server); request->server = tmpprinc; if (krb5_unparse_name(request->server, &sname)) { syslog(LOG_INFO, "TGS_REQ: issuing alternate TGT"); } else { syslog(LOG_INFO, "TGS_REQ: issuing TGT %s", sname); free(sname); } return; } krb5_db_free_principal(server, *nprincs); continue; } *nprincs = 0; *more = FALSE; krb5_free_realm_tree(plist); return; }