oysteikt/heimdal
0
0
Fork 0
Code Issues 5 Pull Requests Releases Activity
Files
1de9ecd91564da40a5588ca024704cdbde84ea37
heimdal/kdc/kerberos5.c
Assar Westerlund 1de9ecd915 fix check for keyed and collision-proof checksum 
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@3546 ec53bebd-3082-4978-b11e-865c3cabbd6b
1997-09-23 07:35:52 +00:00

1330 lines
33 KiB
C
Raw Blame History

/*
* Copyright (c) 1997 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. 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.
*
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Kungliga Tekniska
* Högskolan and its contributors.
*
* 4. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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 "kdc_locl.h"
RCSID("$Id$");
#define MAX_TIME ((time_t)((1U << 31) - 1))
static void
fix_time(time_t **t)
{
if(*t == NULL){
ALLOC(*t);
**t = MAX_TIME;
}
if(**t == 0) **t = MAX_TIME; /* fix for old clients */
}
static void
set_salt_padata (METHOD_DATA **m, Salt *salt)
{
if (salt) {
ALLOC(*m);
(*m)->len = 1;
ALLOC((*m)->val);
(*m)->val->padata_type = salt->type;
copy_octet_string(&salt->salt,
&(*m)->val->padata_value);
}
}
krb5_error_code
as_rep(KDC_REQ *req,
krb5_data *reply,
const char *from)
{
KDC_REQ_BODY *b = &req->req_body;
AS_REP rep;
KDCOptions f = b->kdc_options;
hdb_entry *client = NULL, *server = NULL;
krb5_enctype cetype, setype;
krb5_keytype sess_ktype;
EncTicketPart et;
EncKDCRepPart ek;
krb5_principal client_princ, server_princ;
char *client_name, *server_name;
krb5_error_code ret = 0;
const char *e_text = NULL;
int i;
Key *ckey, *skey, *ekey;
if(b->sname == NULL){
server_name = "<unknown server>";
ret = KRB5KRB_ERR_GENERIC;
e_text = "No server in request";
} else{
principalname2krb5_principal (&server_princ, *(b->sname), b->realm);
krb5_unparse_name(context, server_princ, &server_name);
}
if(b->cname == NULL){
client_name = "<unknown client>";
ret = KRB5KRB_ERR_GENERIC;
e_text = "No client in request";
} else {
principalname2krb5_principal (&client_princ, *(b->cname), b->realm);
krb5_unparse_name(context, client_princ, &client_name);
}
kdc_log(0, "AS-REQ %s from %s for %s",
client_name, from, server_name);
if(ret)
goto out;
client = db_fetch(client_princ);
if(client == NULL){
kdc_log(0, "UNKNOWN -- %s", client_name);
ret = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
goto out;
}
if (client->valid_start && *client->valid_start > kdc_time) {
kdc_log(0, "Client not yet valid -- %s", client_name);
ret = KRB5KDC_ERR_CLIENT_NOTYET;
goto out;
}
if (client->valid_end && *client->valid_end < kdc_time) {
kdc_log(0, "Client expired -- %s", client_name);
ret = KRB5KDC_ERR_NAME_EXP;
goto out;
}
server = db_fetch(server_princ);
if(server == NULL){
kdc_log(0, "UNKNOWN -- %s", server_name);
ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
goto out;
}
if (server->valid_start && *server->valid_start > kdc_time) {
kdc_log(0, "Server not yet valid -- %s", server_name);
ret = KRB5KDC_ERR_SERVICE_NOTYET;
goto out;
}
if (server->valid_end && *server->valid_end < kdc_time) {
kdc_log(0, "Server expired -- %s", server_name);
ret = KRB5KDC_ERR_SERVICE_EXP;
goto out;
}
if(!client->flags.client){
ret = KRB5KDC_ERR_POLICY;
kdc_log(0, "Principal may not act as client -- %s",
client_name);
goto out;
}
if(!server->flags.server){
ret = KRB5KDC_ERR_POLICY;
kdc_log(0, "Principal (%s) may not act as server -- %s",
server_name, client_name);
goto out;
}
if (client->flags.invalid) {
ret = KRB5KDC_ERR_POLICY;
kdc_log(0, "Client (%s) has invalid bit set", client_name);
goto out;
}
if (server->flags.invalid) {
ret = KRB5KDC_ERR_POLICY;
kdc_log(0, "Server (%s) has invalid bit set", server_name);
goto out;
}
if (client->pw_end && *client->pw_end < kdc_time
&& !server->flags.change_pw) {
ret = KRB5KDC_ERR_KEY_EXPIRED;
kdc_log(0, "Client (%s)'s key has expired", client_name);
goto out;
}
memset(&et, 0, sizeof(et));
memset(&ek, 0, sizeof(ek));
if(req->padata){
int i;
PA_DATA *pa;
int found_pa = 0;
kdc_log(5, "Looking for pa-data -- %s", client_name);
for(i = 0; i < req->padata->len; i++){
PA_DATA *pa = &req->padata->val[i];
if(pa->padata_type == pa_enc_timestamp){
krb5_data ts_data;
PA_ENC_TS_ENC p;
time_t patime;
size_t len;
EncryptedData enc_data;
Key *pa_key;
kdc_log(5, "Found pa-enc-timestamp -- %s",
client_name);
found_pa = 1;
ret = decode_EncryptedData(pa->padata_value.data,
pa->padata_value.length,
&enc_data,
&len);
if (ret) {
ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
kdc_log(5, "Failed to decode PA-DATA -- %s",
client_name);
goto out;
}
ret = hdb_etype2key(context, client, enc_data.etype, &pa_key);
if(ret){
free_EncryptedData(&enc_data);
continue;
}
ekey = unseal_key(pa_key);
ret = krb5_decrypt (context,
enc_data.cipher.data,
enc_data.cipher.length,
enc_data.etype,
&ekey->key,
&ts_data);
hdb_free_key(ekey);
free_EncryptedData(&enc_data);
if(ret){
e_text = "Failed to decrypt PA-DATA";
kdc_log (5, "Failed to decrypt PA-DATA -- %s",
client_name);
ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
continue;
}
ret = decode_PA_ENC_TS_ENC(ts_data.data,
ts_data.length,
&p,
&len);
krb5_data_free(&ts_data);
if(ret){
e_text = "Failed to decode PA-ENC-TS-ENC";
ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
kdc_log (5, "Failed to decode PA-ENC-TS_ENC -- %s",
client_name);
continue;
}
patime = p.patimestamp;
free_PA_ENC_TS_ENC(&p);
if (abs(kdc_time - p.patimestamp) > context->max_skew) {
ret = KRB5KDC_ERR_PREAUTH_FAILED;
krb5_mk_error (context,
ret,
"Too large time skew",
NULL,
client_princ,
server_princ,
0,
reply);
kdc_log(0, "Too large time skew -- %s",
client_name);
goto out2;
}
et.flags.pre_authent = 1;
kdc_log(2, "Pre-authentication succeded -- %s",
client_name);
break;
} else {
kdc_log(5, "Found pa-data of type %d -- %s",
pa->padata_type, client_name);
}
}
/* XXX */
if(found_pa == 0 && require_preauth)
goto use_pa;
/* We come here if we found a pa-enc-timestamp, but if there
was some problem with it, other than too large skew */
if(et.flags.pre_authent == 0){
kdc_log(0, "%s -- %s", e_text, client_name);
e_text = NULL;
goto out;
}
}else if (require_preauth || client->flags.require_preauth) {
METHOD_DATA method_data;
PA_DATA pa_data;
u_char buf[16];
size_t len;
krb5_data foo_data;
use_pa:
method_data.len = 1;
method_data.val = &pa_data;
pa_data.padata_type = pa_enc_timestamp;
pa_data.padata_value.length = 0;
pa_data.padata_value.data = NULL;
encode_METHOD_DATA(buf + sizeof(buf) - 1,
sizeof(buf),
&method_data,
&len);
foo_data.length = len;
foo_data.data = buf + sizeof(buf) - len;
ret = KRB5KDC_ERR_PREAUTH_REQUIRED;
krb5_mk_error(context,
ret,
"Need to use PA-ENC-TIMESTAMP",
&foo_data,
client_princ,
server_princ,
0,
reply);
kdc_log(0, "No PA-ENC-TIMESTAMP -- %s", client_name);
goto out2;
}
/* find client key */
for(i = 0; i < b->etype.len; i++){
ret = hdb_etype2key(context, client, b->etype.val[i], &ckey);
if(ret == 0)
break;
}
if(ret){
ret = KRB5KDC_ERR_ETYPE_NOSUPP;
kdc_log(0, "No support for etypes -- %s", client_name);
goto out;
}
cetype = b->etype.val[i];
/* find sesion key type */
for(i = 0; i < b->etype.len; i++){
ret = hdb_etype2key(context, server, b->etype.val[i], &skey);
if(ret == 0)
break;
}
if(ret){
ret = KRB5KDC_ERR_ETYPE_NOSUPP;
kdc_log(0, "No support for etypes -- %s", client_name);
goto out;
}
sess_ktype = skey->key.keytype;
/* find server key */
skey = NULL;
#define is_better(x, y) ((x) > (y))
for(i = 0; i < server->keys.len; i++){
if(skey == NULL || is_better(server->keys.val[i].key.keytype,
skey->key.keytype))
skey = &server->keys.val[i];
}
if(skey == NULL){
ret = KRB5KDC_ERR_NULL_KEY;
kdc_log(0, "No key found for server");
goto out;
}
ret = krb5_keytype_to_etype(context, skey->key.keytype, &setype);
{
char *cet, *set, *skt;
krb5_etype_to_string(context, cetype, &cet);
if(cetype != setype)
krb5_etype_to_string(context, setype, &set);
krb5_keytype_to_string(context, sess_ktype, &skt);
if(cetype != setype)
kdc_log(5, "Using %s/%s/%s", cet, set, skt);
else
kdc_log(5, "Using %s/%s", cet, skt);
free(cet);
if(cetype != setype)
free(set);
free(skt);
}
memset(&rep, 0, sizeof(rep));
rep.pvno = 5;
rep.msg_type = krb_as_rep;
copy_Realm(&b->realm, &rep.crealm);
copy_PrincipalName(b->cname, &rep.cname);
rep.ticket.tkt_vno = 5;
copy_Realm(&b->realm, &rep.ticket.realm);
copy_PrincipalName(b->sname, &rep.ticket.sname);
if(f.renew || f.validate || f.proxy || f.forwarded || f.enc_tkt_in_skey){
ret = KRB5KDC_ERR_BADOPTION;
kdc_log(0, "Bad KDC options -- %s", client_name);
goto out;
}
et.flags.initial = 1;
if(client->flags.forwardable && server->flags.forwardable)
et.flags.forwardable = f.forwardable;
else if (f.forwardable) {
ret = KRB5KDC_ERR_POLICY;
kdc_log(0, "Ticket may not be forwardable -- %s", client_name);
goto out;
}
if(client->flags.proxiable && server->flags.proxiable)
et.flags.proxiable = f.proxiable;
else if (f.proxiable) {
ret = KRB5KDC_ERR_POLICY;
kdc_log(0, "Ticket may not be proxiable -- %s", client_name);
goto out;
}
if(client->flags.postdate && server->flags.postdate)
et.flags.may_postdate = f.allow_postdate;
else if (f.allow_postdate){
ret = KRB5KDC_ERR_POLICY;
kdc_log(0, "Ticket may not be postdatable -- %s", client_name);
goto out;
}
krb5_generate_random_keyblock(context, sess_ktype, &et.key);
copy_PrincipalName(b->cname, &et.cname);
copy_Realm(&b->realm, &et.crealm);
{
time_t start;
time_t t;
start = et.authtime = kdc_time;
if(f.postdated && req->req_body.from){
ALLOC(et.starttime);
start = *et.starttime = *req->req_body.from;
et.flags.invalid = 1;
et.flags.postdated = 1; /* XXX ??? */
kdc_log(2, "Postdated ticket requested -- %s",
client_name);
}
fix_time(&b->till);
t = *b->till;
if(client->max_life)
t = min(t, start + *client->max_life);
if(server->max_life)
t = min(t, start + *server->max_life);
#if 0
t = min(t, start + realm->max_life);
#endif
et.endtime = t;
if(f.renewable_ok && et.endtime < *b->till){
f.renewable = 1;
if(b->rtime == NULL){
ALLOC(b->rtime);
*b->rtime = 0;
}
if(*b->rtime < *b->till)
*b->rtime = *b->till;
}
if(f.renewable && b->rtime){
t = *b->rtime;
if(t == 0)
t = MAX_TIME;
if(client->max_renew)
t = min(t, start + *client->max_renew);
if(server->max_renew)
t = min(t, start + *server->max_renew);
#if 0
t = min(t, start + realm->max_renew);
#endif
ALLOC(et.renew_till);
*et.renew_till = t;
et.flags.renewable = 1;
}
}
if(b->addresses){
ALLOC(et.caddr);
copy_HostAddresses(b->addresses, et.caddr);
}
copy_EncryptionKey(&et.key, &ek.key);
/* The MIT ASN.1 library (obviously) doesn't tell lengths encoded
* as 0 and as 0x80 (meaning indefinite length) apart, and is thus
* incapable to correctly decode vectors of zero length.
*
* To fix this, always send at least one no-op last_req
*
* If there's a pw_end or valid_end we will use that,
* otherwise just a dummy lr.
*/
ek.last_req.val = malloc(2 * sizeof(*ek.last_req.val));
ek.last_req.len = 0;
if (client->pw_end
&& (kdc_warn_pwexpire == 0
|| kdc_time + kdc_warn_pwexpire <= *client->pw_end)) {
ek.last_req.val[ek.last_req.len].lr_type = 6;
ek.last_req.val[ek.last_req.len].lr_value = *client->pw_end;
++ek.last_req.len;
}
if (client->valid_end) {
ek.last_req.val[ek.last_req.len].lr_type = 7;
ek.last_req.val[ek.last_req.len].lr_value = *client->valid_end;
++ek.last_req.len;
}
if (ek.last_req.len == 0) {
ek.last_req.val[ek.last_req.len].lr_type = 0;
ek.last_req.val[ek.last_req.len].lr_value = 0;
++ek.last_req.len;
}
ek.nonce = b->nonce;
if (client->valid_end || client->pw_end) {
ALLOC(ek.key_expiration);
if (client->valid_end)
if (client->pw_end)
*ek.key_expiration = min(*client->valid_end, *client->pw_end);
else
*ek.key_expiration = *client->valid_end;
else
*ek.key_expiration = *client->pw_end;
} else
ek.key_expiration = NULL;
ek.flags = et.flags;
ek.authtime = et.authtime;
if (et.starttime) {
ALLOC(ek.starttime);
*ek.starttime = *et.starttime;
} else
ek.starttime = et.starttime;
ek.endtime = et.endtime;
if (et.renew_till) {
ALLOC(ek.renew_till);
*ek.renew_till = *et.renew_till;
} else
ek.renew_till = et.renew_till;
copy_Realm(&rep.ticket.realm, &ek.srealm);
copy_PrincipalName(&rep.ticket.sname, &ek.sname);
if(et.caddr){
ALLOC(ek.caddr);
copy_HostAddresses(et.caddr, ek.caddr);
}
{
unsigned char buf[8192]; /* XXX The data could be indefinite */
size_t len;
ret = encode_EncTicketPart(buf + sizeof(buf) - 1, sizeof(buf),
&et, &len);
free_EncTicketPart(&et);
if(ret) {
kdc_log(0, "Failed to encode ticket -- %s", client);
goto out;
}
ekey = unseal_key(skey);
krb5_encrypt_EncryptedData(context,
buf + sizeof(buf) - len,
len,
setype,
server->kvno,
&ekey->key,
&rep.ticket.enc_part);
hdb_free_key(ekey);
ret = encode_EncASRepPart(buf + sizeof(buf) - 1, sizeof(buf),
&ek, &len);
free_EncKDCRepPart(&ek);
if(ret) {
kdc_log(0, "Failed to encode KDC-REP -- %s", client_name);
goto out;
}
ekey = unseal_key(ckey);
krb5_encrypt_EncryptedData(context,
buf + sizeof(buf) - len,
len,
cetype,
client->kvno,
&ekey->key,
&rep.enc_part);
hdb_free_key(ekey);
set_salt_padata (&rep.padata, ckey->salt);
ret = encode_AS_REP(buf + sizeof(buf) - 1, sizeof(buf), &rep, &len);
free_AS_REP(&rep);
if(ret) {
kdc_log(0, "Failed to encode AS-REP -- %s", client_name);
goto out;
}
krb5_data_copy(reply, buf + sizeof(buf) - len, len);
}
out:
if(ret){
krb5_mk_error(context,
ret,
e_text,
NULL,
client_princ,
server_princ,
0,
reply);
}
out2:
krb5_free_principal(context, client_princ);
free(client_name);
krb5_free_principal(context, server_princ);
free(server_name);
if(client){
hdb_free_entry(context, client);
free(client);
}
if(server){
hdb_free_entry(context, server);
free(server);
}
return ret;
}
static krb5_error_code
check_tgs_flags(KDC_REQ_BODY *b, EncTicketPart *tgt, EncTicketPart *et)
{
KDCOptions f = b->kdc_options;
if(f.validate){
if(!tgt->flags.invalid || tgt->starttime == NULL){
kdc_log(0, "Bad request to validate ticket");
return KRB5KDC_ERR_BADOPTION;
}
if(*tgt->starttime < kdc_time){
kdc_log(0, "Early request to validate ticket");
return KRB5KRB_AP_ERR_TKT_NYV;
}
/* XXX tkt = tgt */
et->flags.invalid = 0;
}else if(tgt->flags.invalid){
kdc_log(0, "Ticket-granting ticket has INVALID flag set");
return KRB5KRB_AP_ERR_TKT_INVALID;
}
if(f.forwardable){
if(!tgt->flags.forwardable){
kdc_log(0, "Bad request for forwardable ticket");
return KRB5KDC_ERR_BADOPTION;
}
et->flags.forwardable = 1;
}
if(f.forwarded){
if(!tgt->flags.forwardable){
kdc_log(0, "Request to forward non-forwardable ticket");
return KRB5KDC_ERR_BADOPTION;
}
et->flags.forwarded = 1;
et->caddr = b->addresses;
}
if(tgt->flags.forwarded)
et->flags.forwarded = 1;
if(f.proxiable){
if(!tgt->flags.proxiable){
kdc_log(0, "Bad request for proxiable ticket");
return KRB5KDC_ERR_BADOPTION;
}
et->flags.proxiable = 1;
}
if(f.proxy){
if(!tgt->flags.proxiable){
kdc_log(0, "Request to proxy non-proxiable ticket");
return KRB5KDC_ERR_BADOPTION;
}
et->flags.proxy = 1;
et->caddr = b->addresses;
}
if(tgt->flags.proxy)
et->flags.proxy = 1;
if(f.allow_postdate){
if(!tgt->flags.may_postdate){
kdc_log(0, "Bad request for post-datable ticket");
return KRB5KDC_ERR_BADOPTION;
}
et->flags.may_postdate = 1;
}
if(f.postdated){
if(!tgt->flags.may_postdate){
kdc_log(0, "Bad request for postdated ticket");
return KRB5KDC_ERR_BADOPTION;
}
if(b->from)
*et->starttime = *b->from;
et->flags.postdated = 1;
et->flags.invalid = 1;
}else if(b->from && *b->from > kdc_time + context->max_skew){
kdc_log(0, "Ticket cannot be postdated");
return KRB5KDC_ERR_CANNOT_POSTDATE;
}
if(f.renewable){
if(!tgt->flags.renewable){
kdc_log(0, "Bad request for renewable ticket");
return KRB5KDC_ERR_BADOPTION;
}
et->flags.renewable = 1;
ALLOC(et->renew_till);
*et->renew_till = *b->rtime;
}
if(f.renew){
time_t old_life;
if(!tgt->flags.renewable || tgt->renew_till == NULL){
kdc_log(0, "Request to renew non-renewable ticket");
return KRB5KDC_ERR_BADOPTION;
}
old_life = tgt->endtime;
if(tgt->starttime)
old_life -= *tgt->starttime;
else
old_life -= tgt->authtime;
et->endtime = *et->starttime + old_life;
}
/* check for excess flags */
return 0;
}
static krb5_error_code
fix_transited_encoding(TransitedEncoding *tr,
const char *client_realm,
const char *server_realm,
const char *tgt_realm)
{
krb5_error_code ret = 0;
if(strcmp(client_realm, tgt_realm) && strcmp(server_realm, tgt_realm)){
char **realms = NULL, **tmp;
int num_realms = 0;
int i;
if(tr->tr_type){
if(tr->tr_type != DOMAIN_X500_COMPRESS){
kdc_log(0, "Unknown transited type: %u",
tr->tr_type);
return KRB5KDC_ERR_TRTYPE_NOSUPP;
}
ret = krb5_domain_x500_decode(tr->contents,
&realms,
&num_realms,
client_realm,
server_realm);
if(ret){
krb5_warn(context, ret, "Decoding transited encoding");
return ret;
}
}
tmp = realloc(realms, (num_realms + 1) * sizeof(*realms));
if(tmp == NULL){
ret = ENOMEM;
goto free_realms;
}
realms = tmp;
realms[num_realms] = strdup(tgt_realm);
if(realms[num_realms] == NULL){
ret = ENOMEM;
goto free_realms;
}
num_realms++;
free_TransitedEncoding(tr);
tr->tr_type = DOMAIN_X500_COMPRESS;
ret = krb5_domain_x500_encode(realms, num_realms, &tr->contents);
if(ret)
krb5_warn(context, ret, "Encoding transited encoding");
free_realms:
for(i = 0; i < num_realms; i++)
free(realms[i]);
free(realms);
}
return ret;
}
static krb5_error_code
tgs_make_reply(KDC_REQ_BODY *b, EncTicketPart *tgt,
hdb_entry *server, hdb_entry *client,
krb5_principal client_principal,
hdb_entry *krbtgt,
krb5_enctype cetype,
krb5_data *reply)
{
KDC_REP rep;
EncKDCRepPart ek;
EncTicketPart et;
KDCOptions f = b->kdc_options;
krb5_error_code ret;
int i;
krb5_enctype setype;
Key *skey, *ekey;
krb5_keytype sess_ktype;
/* Find appropriate key */
for(i = 0; i < b->etype.len; i++){
ret = hdb_etype2key(context, server, b->etype.val[i], &skey);
if(ret == 0)
break;
}
if(ret){
kdc_log(0, "Failed to find requested etype");
return KRB5KDC_ERR_ETYPE_NOSUPP;
}
sess_ktype = skey->key.keytype;
skey = NULL;
for(i = 0; i < server->keys.len; i++){
if(skey == NULL || is_better(server->keys.val[i].key.keytype,
skey->key.keytype))
skey = &server->keys.val[i];
}
if(skey == NULL){
ret = KRB5KDC_ERR_NULL_KEY;
kdc_log(0, "No key found for server");
goto out;
}
ret = krb5_keytype_to_etype(context, skey->key.keytype, &setype);
memset(&rep, 0, sizeof(rep));
memset(&et, 0, sizeof(et));
memset(&ek, 0, sizeof(ek));
rep.pvno = 5;
rep.msg_type = krb_tgs_rep;
et.authtime = tgt->authtime;
fix_time(&b->till);
et.endtime = min(tgt->endtime, *b->till);
ALLOC(et.starttime);
*et.starttime = kdc_time;
ret = check_tgs_flags(b, tgt, &et);
if(ret)
return ret;
copy_TransitedEncoding(&tgt->transited, &et.transited);
ret = fix_transited_encoding(&et.transited,
*krb5_princ_realm(context, client_principal),
*krb5_princ_realm(context, server->principal),
*krb5_princ_realm(context, krbtgt->principal));
if(ret){
free_TransitedEncoding(&et.transited);
return ret;
}
copy_Realm(krb5_princ_realm(context, server->principal),
&rep.ticket.realm);
krb5_principal2principalname(&rep.ticket.sname, server->principal);
copy_Realm(&tgt->crealm, &rep.crealm);
copy_PrincipalName(&tgt->cname, &rep.cname);
rep.ticket.tkt_vno = 5;
ek.caddr = et.caddr;
if(et.caddr == NULL)
et.caddr = tgt->caddr;
{
time_t life;
life = et.endtime - *et.starttime;
if(client && client->max_life)
life = min(life, *client->max_life);
if(server->max_life)
life = min(life, *server->max_life);
et.endtime = *et.starttime + life;
}
if(f.renewable_ok && tgt->flags.renewable &&
et.renew_till == NULL && et.endtime < *b->till){
et.flags.renewable = 1;
ALLOC(et.renew_till);
*et.renew_till = *b->till;
}
if(et.renew_till){
time_t renew;
renew = *et.renew_till - et.authtime;
if(client && client->max_renew)
renew = min(renew, *client->max_renew);
if(server->max_renew)
renew = min(renew, *server->max_renew);
*et.renew_till = et.authtime + renew;
}
if(et.renew_till){
*et.renew_till = min(*et.renew_till, *tgt->renew_till);
*et.starttime = min(*et.starttime, *et.renew_till);
et.endtime = min(et.endtime, *et.renew_till);
}
*et.starttime = min(*et.starttime, et.endtime);
if(*et.starttime == et.endtime){
ret = KRB5KDC_ERR_NEVER_VALID;
goto out;
}
if(et.renew_till && et.endtime == *et.renew_till){
free(et.renew_till);
et.renew_till = NULL;
et.flags.renewable = 0;
}
et.flags.pre_authent = tgt->flags.pre_authent;
et.flags.hw_authent = tgt->flags.hw_authent;
/* XXX Check enc-authorization-data */
krb5_generate_random_keyblock(context, sess_ktype, &et.key);
et.crealm = tgt->crealm;
et.cname = tgt->cname;
ek.key = et.key;
/* MIT must have at least one last_req */
ek.last_req.len = 1;
ek.last_req.val = calloc(1, sizeof(*ek.last_req.val));
ek.nonce = b->nonce;
ek.flags = et.flags;
ek.authtime = et.authtime;
ek.starttime = et.starttime;
ek.endtime = et.endtime;
ek.renew_till = et.renew_till;
ek.srealm = rep.ticket.realm;
ek.sname = rep.ticket.sname;
{
unsigned char buf[8192]; /* XXX The data could be indefinite */
size_t len;
ret = encode_EncTicketPart(buf + sizeof(buf) - 1,
sizeof(buf), &et, &len);
if(ret){
kdc_log(0, "Failed to encode EncTicketPart: %s",
krb5_get_err_text(context, ret));
goto out;
}
ekey = unseal_key(skey);
krb5_encrypt_EncryptedData(context, buf + sizeof(buf) - len, len,
setype,
server->kvno,
&ekey->key,
&rep.ticket.enc_part);
hdb_free_key(ekey);
ret = encode_EncTGSRepPart(buf + sizeof(buf) - 1,
sizeof(buf), &ek, &len);
if(ret){
kdc_log(0, "Failed to encode EncTicketPart: %s",
krb5_get_err_text(context, ret));
goto out;
}
/* It is somewhat unclear where the etype in the following
encryption should come from. What we have is a session
key in the passed tgt, and a list of preferred etypes
*for the new ticket*. Should we pick the best possible
etype, given the keytype in the tgt, or should we look
at the etype list here as well? What if the tgt
session key is DES3 and we want a ticket with a (say)
CAST session key. Should the DES3 etype be added to the
etype list, even if we don't want a session key with
DES3? */
krb5_encrypt_EncryptedData(context,
buf + sizeof(buf) - len, len,
cetype,
0,
&tgt->key,
&rep.enc_part);
ret = encode_TGS_REP(buf + sizeof(buf) - 1, sizeof(buf), &rep, &len);
if(ret){
kdc_log(0, "Failed to encode TGS-REP: %s",
krb5_get_err_text(context, ret));
goto out;
}
krb5_data_copy(reply, buf + sizeof(buf) - len, len);
out:
free_TGS_REP(&rep);
free_TransitedEncoding(&et.transited);
if(et.starttime)
free(et.starttime);
if(et.renew_till)
free(et.renew_till);
free_LastReq(&ek.last_req);
memset(et.key.keyvalue.data, 0, et.key.keyvalue.length);
free_EncryptionKey(&et.key);
}
return ret;
}
static krb5_error_code
tgs_check_authenticator(krb5_auth_context ac,
KDC_REQ_BODY *b, krb5_keyblock *key)
{
krb5_authenticator auth;
size_t len;
unsigned char buf[8192];
krb5_error_code ret;
krb5_auth_getauthenticator(context, ac, &auth);
if(auth->cksum == NULL){
kdc_log(0, "No authenticator in request");
ret = KRB5KRB_AP_ERR_INAPP_CKSUM;
goto out;
}
if (!krb5_checksum_is_keyed(auth->cksum->cksumtype)
|| !krb5_checksum_is_collision_proof(auth->cksum->cksumtype)) {
kdc_log(0, "Bad checksum type in authenticator: %d",
auth->cksum->cksumtype);
ret = KRB5KRB_AP_ERR_INAPP_CKSUM;
goto out;
}
/* XXX */
ret = encode_KDC_REQ_BODY(buf + sizeof(buf) - 1, sizeof(buf),
b, &len);
if(ret){
kdc_log(0, "Failed to encode KDC-REQ-BODY: %s",
krb5_get_err_text(context, ret));
goto out;
}
ret = krb5_verify_checksum(context, buf + sizeof(buf) - len, len,
key,
auth->cksum);
if(ret){
kdc_log(0, "Failed to verify checksum: %s",
krb5_get_err_text(context, ret));
}
out:
free_Authenticator(auth);
free(auth);
return ret;
}
static Realm
is_krbtgt(PrincipalName *p)
{
if(p->name_string.len == 2 && strcmp(p->name_string.val[0], "krbtgt") == 0)
return p->name_string.val[1];
else
return NULL;
}
static Realm
find_rpath(Realm r)
{
const char *new_realm = krb5_config_get_string(context->cf,
"libdefaults",
"capath",
r,
NULL);
return (Realm)new_realm;
}
static krb5_error_code
tgs_rep2(KDC_REQ_BODY *b,
PA_DATA *pa_data,
krb5_data *reply,
const char *from)
{
krb5_ap_req ap_req;
size_t len;
krb5_error_code ret;
krb5_principal princ;
krb5_auth_context ac = NULL;
krb5_ticket *ticket = NULL;
krb5_flags ap_req_options;
const char *e_text = NULL;
hdb_entry *krbtgt;
EncTicketPart *tgt;
Key *tkey, *ekey;
krb5_enctype cetype;
krb5_principal cp = NULL;
krb5_principal sp = NULL;
memset(&ap_req, 0, sizeof(ap_req));
ret = krb5_decode_ap_req(context, &pa_data->padata_value, &ap_req);
if(ret){
kdc_log(0, "Failed to decode AP-REQ: %s",
krb5_get_err_text(context, ret));
goto out2;
}
if(!is_krbtgt(&ap_req.ticket.sname)){
kdc_log(0, "PA-DATA is not a ticket-granting ticket");
ret = KRB5KDC_ERR_POLICY; /* ? */
goto out2;
}
principalname2krb5_principal(&princ,
ap_req.ticket.sname,
ap_req.ticket.realm);
krbtgt = db_fetch(princ);
if(krbtgt == NULL) {
char *p;
krb5_unparse_name(context, princ, &p);
kdc_log(0, "Ticket-granting ticket not found in database: %s", p);
free(p);
ret = KRB5KRB_AP_ERR_NOT_US;
goto out2;
}
ret = hdb_etype2key(context, krbtgt, ap_req.ticket.enc_part.etype, &tkey);
if(ret){
char *str;
krb5_etype_to_string(context, ap_req.ticket.enc_part.etype, &str);
kdc_log(0, "No server key found for %s", str);
free(str);
ret = KRB5KRB_AP_ERR_BADKEYVER;
goto out2;
}
ekey = unseal_key(tkey);
ret = krb5_verify_ap_req(context,
&ac,
&ap_req,
princ,
&ekey->key,
&ap_req_options,
&ticket);
hdb_free_key(ekey);
krb5_free_principal(context, princ);
if(ret) {
kdc_log(0, "Failed to verify AP-REQ: %s",
krb5_get_err_text(context, ret));
goto out2;
}
cetype = ap_req.authenticator.etype;
tgt = &ticket->ticket;
ret = tgs_check_authenticator(ac, b, &tgt->key);
krb5_auth_con_free(context, ac);
if(ret){
kdc_log(0, "Failed to verify authenticator: %s",
krb5_get_err_text(context, ret));
goto out2;
}
{
PrincipalName *s;
Realm r;
char *spn = NULL, *cpn = NULL;
hdb_entry *server = NULL, *client = NULL;
TransitedEncoding tr;
int loop = 0;
s = b->sname;
r = b->realm;
#if 0
if(b->kdc_options.enc_tkt_in_skey){
Ticket *t;
hdb_entry *uu;
krb5_principal p;
Key *tkey;
if(b->additional_tickets == NULL){
ret = KRB5KDC_ERR_BADOPTION; /* ? */
kdc_log(0, "No second ticket present in request");
goto out;
}
t = &b->additional_tickets->val[0];
principalname2krb5_principal(&p, t->sname, t->realm);
uu = db_fetch(p);
krb5_free_principal(context, p);
if(uu == NULL){
ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
goto out;
}
ret = hdb_etype2key(context, uu, t->enc_part.etype, &tkey);
if(ret){
ret = KRB5KDC_ERR_ETYPE_NOSUPP; /* XXX */
goto out;
}
ekey = unseal_key(tkey);
ret = krb5_decrypt_EncryptedData(context, &t->enc_part,
&ekey->key, &result);
if(ret){
/* XXX */
goto out;
}
ret = decode_EncTicketPart(result.data, result.length, &ct, &len);
if(ret){
goto out;
}
s = ct.cname;
r = ct.crealm;
}
#endif
principalname2krb5_principal(&sp, *s, r);
krb5_unparse_name(context, sp, &spn);
principalname2krb5_principal(&cp, tgt->cname, tgt->crealm);
krb5_unparse_name(context, cp, &cpn);
kdc_log(0, "TGS-REQ %s from %s for %s", cpn, from, spn);
server_lookup:
server = db_fetch(sp);
if(server == NULL){
Realm req_rlm, new_rlm;
if(loop++ < 2 && (req_rlm = is_krbtgt(&sp->name))){
new_rlm = find_rpath(req_rlm);
if(new_rlm){
kdc_log(5, "krbtgt for realm %s not found, trying %s",
req_rlm, new_rlm);
krb5_free_principal(context, sp);
free(spn);
krb5_make_principal(context, &sp, r,
"krbtgt", new_rlm, NULL);
krb5_unparse_name(context, sp, &spn);
goto server_lookup;
}
}
kdc_log(0, "Server not found in database: %s", spn);
ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
goto out;
}
client = db_fetch(cp);
if(client == NULL)
kdc_log(1, "Client not found in database: %s", cpn);
#if 0
/* XXX check client only if same realm as krbtgt-instance */
if(client == NULL){
kdc_log(0, "Client not found in database: %s", cpn);
ret = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
goto out;
}
#endif
if((b->kdc_options.validate || b->kdc_options.renew) &&
!krb5_principal_compare(context,
krbtgt->principal,
server->principal)){
kdc_log(0, "Inconsistent request.");
ret = KRB5KDC_ERR_SERVER_NOMATCH;
goto out;
}
ret = tgs_make_reply(b, tgt, server, client, cp,
krbtgt, cetype, reply);
out:
free(spn);
free(cpn);
if(server){
hdb_free_entry(context, server);
free(server);
}
if(client){
hdb_free_entry(context, client);
free(client);
}
}
out2:
if(ret)
krb5_mk_error(context,
ret,
e_text,
NULL,
cp,
sp,
0,
reply);
krb5_free_principal(context, cp);
krb5_free_principal(context, sp);
if (ticket) {
krb5_free_ticket(context, ticket);
free(ticket);
}
free_AP_REQ(&ap_req);
if(krbtgt){
hdb_free_entry(context, krbtgt);
free(krbtgt);
}
return ret;
}
krb5_error_code
tgs_rep(KDC_REQ *req,
krb5_data *data,
const char *from)
{
krb5_error_code ret;
int i;
PA_DATA *pa_data = NULL;
if(req->padata == NULL){
ret = KRB5KDC_ERR_PREAUTH_REQUIRED; /* XXX ??? */
kdc_log(0, "TGS-REQ from %s without PA-DATA", from);
goto out;
}
for(i = 0; i < req->padata->len; i++)
if(req->padata->val[i].padata_type == pa_tgs_req){
pa_data = &req->padata->val[i];
break;
}
if(pa_data == NULL){
ret = KRB5KDC_ERR_PADATA_TYPE_NOSUPP;
kdc_log(0, "TGS-REQ from %s without PA-TGS-REQ", from);
goto out;
}
ret = tgs_rep2(&req->req_body, pa_data, data, from);
out:
if(ret && data->data == NULL)
krb5_mk_error(context,
ret,
NULL,
NULL,
NULL,
NULL,
0,
data);
return ret;
}
Reference in New Issue View Git Blame Copy Permalink