#include "k5-int.h"
#include "com_err.h"
#include <syslog.h>
#ifdef HAVE_NETINET_IN_H
#include <sys/types.h>
#include <netinet/in.h>
#ifndef hpux
#include <arpa/inet.h>
#endif
#endif
#include "kdc_util.h"
#include "policy.h"
#include "extern.h"
#include "adm_proto.h"
static void find_alternate_tgs (krb5_kdc_req *, krb5_db_entry *,
krb5_boolean *, int *);
static krb5_error_code prepare_error_tgs (krb5_kdc_req *, krb5_ticket *,
int, const char *, krb5_data **,
const char *);
krb5_error_code
process_tgs_req(krb5_data *pkt, const krb5_fulladdr *from,
krb5_data **response)
{
krb5_keyblock * subkey;
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;
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=0;
krb5_keyblock session_key;
krb5_timestamp until, rtime;
krb5_keyblock encrypting_key;
krb5_key_data *server_key;
char *cname = 0, *sname = 0, *tmp = 0;
const char *fromstring = 0;
krb5_last_req_entry *nolrarray[2], nolrentry;
krb5_enctype useenctype;
int errcode, errcode2;
register int i;
int firstpass = 1;
const char *status = 0;
char ktypestr[128];
char rep_etypestr[128];
char fromstringbuf[70];
session_key.contents = 0;
retval = decode_krb5_tgs_req(pkt, &request);
if (retval)
return retval;
ktypes2str(ktypestr, sizeof(ktypestr),
request->nktypes, request->ktype);
if ((retval = setup_server_realm(request->server)))
return retval;
fromstring = inet_ntop(ADDRTYPE2FAMILY(from->address->addrtype),
from->address->contents,
fromstringbuf, sizeof(fromstringbuf));
if (!fromstring)
fromstring = "<unknown>";
if ((errcode = krb5_unparse_name(kdc_context, request->server, &sname))) {
status = "UNPARSING SERVER";
goto cleanup;
}
limit_string(sname);
errcode = kdc_process_tgs_req(request, from, pkt, &header_ticket, &subkey);
if (header_ticket && header_ticket->enc_part2 &&
(errcode2 = krb5_unparse_name(kdc_context,
header_ticket->enc_part2->client,
&cname))) {
status = "UNPARSING CLIENT";
errcode = errcode2;
goto cleanup;
}
limit_string(cname);
if (errcode) {
status = "PROCESS_TGS";
goto cleanup;
}
if (!header_ticket) {
errcode = KRB5_NO_TKT_SUPPLIED;
status="UNEXPECTED NULL in header_ticket";
goto cleanup;
}
authtime = header_ticket->enc_part2->times.authtime;
nprincs = 1;
if ((errcode = krb5_db_get_principal(kdc_context, request->server, &server,
&nprincs, &more))) {
status = "LOOKING_UP_SERVER";
nprincs = 0;
goto cleanup;
}
tgt_again:
if (more) {
status = "NON_UNIQUE_PRINCIPAL";
errcode = KRB5KDC_ERR_PRINCIPAL_NOT_UNIQUE;
goto cleanup;
} else if (nprincs != 1) {
if (firstpass && krb5_is_tgs_principal(request->server) == TRUE) {
if (krb5_princ_size(kdc_context, request->server) == 2) {
krb5_data *server_1 =
krb5_princ_component(kdc_context, request->server, 1);
krb5_data *tgs_1 =
krb5_princ_component(kdc_context, tgs_server, 1);
if (!tgs_1 || server_1->length != tgs_1->length ||
memcmp(server_1->data, tgs_1->data, tgs_1->length)) {
krb5_db_free_principal(kdc_context, &server, nprincs);
find_alternate_tgs(request, &server, &more, &nprincs);
firstpass = 0;
goto tgt_again;
}
}
}
krb5_db_free_principal(kdc_context, &server, nprincs);
status = "UNKNOWN_SERVER";
errcode = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
goto cleanup;
}
if ((errcode = krb5_timeofday(kdc_context, &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;
}
useenctype = 0;
if (isflagset(request->kdc_options, KDC_OPT_ENC_TKT_IN_SKEY)) {
krb5_keyblock * st_sealing_key;
krb5_kvno st_srv_kvno;
krb5_enctype etype;
if ((errcode = kdc_get_server_key(request->second_ticket[st_idx],
&st_sealing_key,
&st_srv_kvno))) {
status = "2ND_TKT_SERVER";
goto cleanup;
}
errcode = krb5_decrypt_tkt_part(kdc_context, st_sealing_key,
request->second_ticket[st_idx]);
krb5_free_keyblock(kdc_context, st_sealing_key);
if (errcode) {
status = "2ND_TKT_DECRYPT";
goto cleanup;
}
etype = request->second_ticket[st_idx]->enc_part2->session->enctype;
if (!krb5_c_valid_enctype(etype)) {
status = "BAD_ETYPE_IN_2ND_TKT";
errcode = KRB5KDC_ERR_ETYPE_NOSUPP;
goto cleanup;
}
for (i = 0; i < request->nktypes; i++) {
if (request->ktype[i] == etype) {
useenctype = etype;
break;
}
}
}
if ((useenctype == 0) &&
(useenctype = select_session_keytype(kdc_context, &server,
request->nktypes,
request->ktype)) == 0) {
status = "BAD_ENCRYPTION_TYPE";
errcode = KRB5KDC_ERR_ETYPE_NOSUPP;
goto cleanup;
}
errcode = krb5_c_make_random_key(kdc_context, useenctype, &session_key);
if (errcode) {
status = "RANDOM_KEY_FAILED";
goto cleanup;
}
ticket_reply.server = request->server;
enc_tkt_reply.flags = 0;
enc_tkt_reply.times.starttime = 0;
if (!(header_ticket->enc_part2->times.starttime))
header_ticket->enc_part2->times.starttime =
header_ticket->enc_part2->times.authtime;
enc_tkt_reply.caddrs = header_ticket->enc_part2->caddrs;
reply_encpart.caddrs = 0;
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);
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);
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)) {
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;
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 {
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)) {
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;
}
enc_tkt_reply.times.authtime = header_ticket->enc_part2->times.authtime;
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);
if (enc_tkt_reply.times.starttime == enc_tkt_reply.times.authtime)
enc_tkt_reply.times.starttime = 0;
if (request->authorization_data.ciphertext.data) {
krb5_data scratch;
scratch.length = request->authorization_data.ciphertext.length;
if (!(scratch.data =
malloc(request->authorization_data.ciphertext.length))) {
status = "AUTH_NOMEM";
errcode = ENOMEM;
goto cleanup;
}
if ((errcode = krb5_c_decrypt(kdc_context,
header_ticket->enc_part2->session,
KRB5_KEYUSAGE_TGS_REQ_AD_SESSKEY,
0, &request->authorization_data,
&scratch))) {
status = "AUTH_ENCRYPT_FAIL";
free(scratch.data);
goto cleanup;
}
errcode = decode_krb5_authdata(&scratch, &(request->unenc_authdata));
free(scratch.data);
if (errcode) {
status = "AUTH_DECODE";
goto cleanup;
}
if ((errcode =
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;
if (realm_compare(header_ticket->server, tgs_server) ||
realm_compare(header_ticket->server, enc_tkt_reply.client)) {
enc_tkt_reply.transited = header_ticket->enc_part2->transited;
} else {
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.magic = 0;
enc_tkt_transited.tr_contents.magic = 0;
enc_tkt_transited.tr_contents.data = 0;
enc_tkt_transited.tr_contents.length = 0;
enc_tkt_reply.transited = enc_tkt_transited;
if ((errcode =
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;
}
if (!isflagset (request->kdc_options, KDC_OPT_DISABLE_TRANSITED_CHECK)) {
unsigned int tlen;
char *tdots;
errcode = krb5_check_transited_list (kdc_context,
&enc_tkt_reply.transited.tr_contents,
krb5_princ_realm (kdc_context, header_ticket->enc_part2->client),
krb5_princ_realm (kdc_context, request->server));
tlen = enc_tkt_reply.transited.tr_contents.length;
tdots = tlen > 125 ? "..." : "";
tlen = tlen > 125 ? 125 : tlen;
if (errcode == 0) {
setflag (enc_tkt_reply.flags, TKT_FLG_TRANSIT_POLICY_CHECKED);
} else if (errcode == KRB5KRB_AP_ERR_ILL_CR_TKT)
krb5_klog_syslog (LOG_INFO,
"bad realm transit path from '%s' to '%s' "
"via '%.*s%s'",
cname ? cname : "<unknown client>",
sname ? sname : "<unknown server>",
tlen,
enc_tkt_reply.transited.tr_contents.data,
tdots);
else {
const char *emsg = krb5_get_error_message(kdc_context, errcode);
krb5_klog_syslog (LOG_ERR,
"unexpected error checking transit from "
"'%s' to '%s' via '%.*s%s': %s",
cname ? cname : "<unknown client>",
sname ? sname : "<unknown server>",
tlen,
enc_tkt_reply.transited.tr_contents.data,
tdots, emsg);
krb5_free_error_message(kdc_context, emsg);
}
} else
krb5_klog_syslog (LOG_INFO, "not checking transit path");
if (reject_bad_transit
&& !isflagset (enc_tkt_reply.flags, TKT_FLG_TRANSIT_POLICY_CHECKED)) {
errcode = KRB5KDC_ERR_POLICY;
status = "BAD_TRANSIT";
goto cleanup;
}
ticket_reply.enc_part2 = &enc_tkt_reply;
if (isflagset(request->kdc_options, KDC_OPT_ENC_TKT_IN_SKEY)) {
krb5_enc_tkt_part *t2enc = request->second_ticket[st_idx]->enc_part2;
krb5_principal client2 = t2enc->client;
if (!krb5_principal_compare(kdc_context, request->server, client2)) {
if ((errcode = krb5_unparse_name(kdc_context, client2, &tmp)))
tmp = 0;
if (tmp != NULL)
limit_string(tmp);
krb5_klog_syslog(LOG_INFO,
"TGS_REQ %s: 2ND_TKT_MISMATCH: "
"authtime %d, %s for %s, 2nd tkt client %s",
fromstring, authtime,
cname ? cname : "<unknown client>",
sname ? sname : "<unknown server>",
tmp ? tmp : "<unknown>");
errcode = KRB5KDC_ERR_SERVER_NOMATCH;
goto cleanup;
}
ticket_reply.enc_part.kvno = 0;
ticket_reply.enc_part.enctype = t2enc->session->enctype;
if ((errcode = krb5_encrypt_tkt_part(kdc_context, t2enc->session,
&ticket_reply))) {
status = "2ND_TKT_ENCRYPT";
goto cleanup;
}
st_idx++;
} else {
if ((errcode = krb5_dbe_find_enctype(kdc_context, &server,
-1,
-1,
0,
&server_key))) {
status = "FINDING_SERVER_KEY";
goto cleanup;
}
if ((errcode = krb5_dbekd_decrypt_key_data(kdc_context,
&master_keyblock,
server_key, &encrypting_key,
NULL))) {
status = "DECRYPT_SERVER_KEY";
goto cleanup;
}
errcode = krb5_encrypt_tkt_part(kdc_context, &encrypting_key,
&ticket_reply);
krb5_free_keyblock_contents(kdc_context, &encrypting_key);
if (errcode) {
status = "TKT_ENCRYPT";
goto cleanup;
}
ticket_reply.enc_part.kvno = server_key->key_data_kvno;
}
reply.msg_type = KRB5_TGS_REP;
reply.padata = 0;
reply.client = header_ticket->enc_part2->client;
reply.enc_part.kvno = 0;
reply.ticket = &ticket_reply;
reply_encpart.session = &session_key;
reply_encpart.nonce = request->nonce;
reply_encpart.times = enc_tkt_reply.times;
reply_encpart.times.authtime = header_ticket->enc_part2->times.authtime;
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;
reply_encpart.key_exp = 0;
reply_encpart.flags = enc_tkt_reply.flags;
reply_encpart.server = ticket_reply.server;
reply.enc_part.enctype = subkey ? subkey->enctype :
header_ticket->enc_part2->session->enctype;
errcode = krb5_encode_kdc_rep(kdc_context, KRB5_TGS_REP, &reply_encpart,
subkey ? 1 : 0,
subkey ? subkey :
header_ticket->enc_part2->session,
&reply, response);
if (errcode) {
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);
memset(reply.enc_part.ciphertext.data, 0,
reply.enc_part.ciphertext.length);
free(reply.enc_part.ciphertext.data);
cleanup:
if (status) {
const char * emsg = NULL;
if (!errcode)
rep_etypes2str(rep_etypestr, sizeof(rep_etypestr), &reply);
if (errcode)
emsg = krb5_get_error_message (kdc_context, errcode);
krb5_klog_syslog(LOG_INFO,
"TGS_REQ (%s) %s: %s: authtime %d, "
"%s%s %s for %s%s%s",
ktypestr,
fromstring, status, authtime,
!errcode ? rep_etypestr : "",
!errcode ? "," : "",
cname ? cname : "<unknown client>",
sname ? sname : "<unknown server>",
errcode ? ", " : "",
errcode ? emsg : "");
if (errcode)
krb5_free_error_message (kdc_context, emsg);
}
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 > 128)
errcode = KRB_ERR_GENERIC;
retval = prepare_error_tgs(request, header_ticket, errcode,
fromstring, response, status);
if (got_err) {
krb5_free_error_message (kdc_context, status);
status = 0;
}
}
if (header_ticket)
krb5_free_ticket(kdc_context, header_ticket);
if (request)
krb5_free_kdc_req(kdc_context, request);
if (cname)
free(cname);
if (sname)
free(sname);
if (nprincs)
krb5_db_free_principal(kdc_context, &server, 1);
if (session_key.contents)
krb5_free_keyblock_contents(kdc_context, &session_key);
if (newtransited)
free(enc_tkt_reply.transited.tr_contents.data);
return retval;
}
static krb5_error_code
prepare_error_tgs (krb5_kdc_req *request, krb5_ticket *ticket, int error,
const char *ident, krb5_data **response, const char *status)
{
krb5_error errpkt;
krb5_error_code retval;
krb5_data *scratch;
errpkt.ctime = request->nonce;
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 = 0;
errpkt.text.length = strlen(status) + 1;
if (!(errpkt.text.data = malloc(errpkt.text.length)))
return ENOMEM;
(void) strcpy(errpkt.text.data, status);
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(kdc_context, &errpkt, scratch);
free(errpkt.text.data);
if (retval)
free(scratch);
else
*response = scratch;
return retval;
}
static void
find_alternate_tgs(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(kdc_context,
krb5_princ_realm(kdc_context, request->server),
krb5_princ_component(kdc_context, request->server, 1),
&plist, KRB5_REALM_BRANCH_CHAR)))
return;
for (pl2 = plist; *pl2; pl2++);
while (--pl2 > plist) {
*nprincs = 1;
tmp = *krb5_princ_realm(kdc_context, *pl2);
krb5_princ_set_realm(kdc_context, *pl2,
krb5_princ_realm(kdc_context, tgs_server));
retval = krb5_db_get_principal(kdc_context, *pl2, server, nprincs, more);
krb5_princ_set_realm(kdc_context, *pl2, &tmp);
if (retval) {
*nprincs = 0;
*more = FALSE;
krb5_free_realm_tree(kdc_context, plist);
return;
}
if (*more) {
krb5_db_free_principal(kdc_context, server, *nprincs);
continue;
} else if (*nprincs == 1) {
krb5_principal tmpprinc;
char *sname;
tmp = *krb5_princ_realm(kdc_context, *pl2);
krb5_princ_set_realm(kdc_context, *pl2,
krb5_princ_realm(kdc_context, tgs_server));
if ((retval = krb5_copy_principal(kdc_context, *pl2, &tmpprinc))) {
krb5_db_free_principal(kdc_context, server, *nprincs);
krb5_princ_set_realm(kdc_context, *pl2, &tmp);
continue;
}
krb5_princ_set_realm(kdc_context, *pl2, &tmp);
krb5_free_principal(kdc_context, request->server);
request->server = tmpprinc;
if (krb5_unparse_name(kdc_context, request->server, &sname)) {
krb5_klog_syslog(LOG_INFO,
"TGS_REQ: issuing alternate <un-unparseable> TGT");
} else {
limit_string(sname);
krb5_klog_syslog(LOG_INFO,
"TGS_REQ: issuing TGT %s", sname);
free(sname);
}
return;
}
krb5_db_free_principal(kdc_context, server, *nprincs);
continue;
}
*nprincs = 0;
*more = FALSE;
krb5_free_realm_tree(kdc_context, plist);
return;
}