static void
do_getticket (krb5_context context,
krb5_kdc_configuration *config,
struct rx_header *hdr,
krb5_storage *sp,
struct sockaddr_in *addr,
const char *from,
krb5_data *reply)
{
krb5_error_code ret;
int kvno;
char *auth_domain = NULL;
krb5_data aticket;
char *name = NULL;
char *instance = NULL;
krb5_data times;
int32_t max_seq_len;
hdb_entry_ex *server_entry = NULL;
hdb_entry_ex *client_entry = NULL;
hdb_entry_ex *krbtgt_entry = NULL;
Key *kkey = NULL;
Key *skey = NULL;
DES_cblock key;
DES_key_schedule schedule;
DES_cblock session;
time_t max_life;
int8_t life;
time_t start_time, end_time;
char server_name[256];
char client_name[256];
struct _krb5_krb_auth_data ad;
krb5_data_zero (&aticket);
krb5_data_zero (×);
memset(&ad, 0, sizeof(ad));
unparse_getticket_args (sp, &kvno, &auth_domain, &aticket,
&name, &instance, ×, &max_seq_len);
if (times.length < 8) {
make_error_reply (hdr, KABADREQUEST, reply);
goto out;
}
snprintf (server_name, sizeof(server_name),
"%s.%s@%s", name, instance, config->v4_realm);
ret = _kdc_db_fetch4 (context, config, name, instance,
config->v4_realm, HDB_F_GET_SERVER, &server_entry);
if (ret) {
kdc_log(context, config, 0, "Server not found in database: %s: %s",
server_name, krb5_get_err_text(context, ret));
make_error_reply (hdr, KANOENT, reply);
goto out;
}
ret = _kdc_db_fetch4 (context, config, "krbtgt",
config->v4_realm, config->v4_realm, HDB_F_GET_KRBTGT, &krbtgt_entry);
if (ret) {
kdc_log(context, config, 0,
"Server not found in database: %s.%s@%s: %s",
"krbtgt", config->v4_realm, config->v4_realm,
krb5_get_err_text(context, ret));
make_error_reply (hdr, KANOENT, reply);
goto out;
}
/* find a DES key */
ret = _kdc_get_des_key(context, krbtgt_entry, TRUE, TRUE, &kkey);
if(ret){
kdc_log(context, config, 0, "no suitable DES key for krbtgt");
make_error_reply (hdr, KANOKEYS, reply);
goto out;
}
/* find a DES key */
ret = _kdc_get_des_key(context, server_entry, TRUE, TRUE, &skey);
if(ret){
kdc_log(context, config, 0, "no suitable DES key for server");
make_error_reply (hdr, KANOKEYS, reply);
goto out;
}
/* decrypt the incoming ticket */
memcpy (&key, kkey->key.keyvalue.data, sizeof(key));
/* unpack the ticket */
{
char *sname = NULL;
char *sinstance = NULL;
ret = _krb5_krb_decomp_ticket(context, &aticket, &kkey->key,
config->v4_realm, &sname,
&sinstance, &ad);
if (ret) {
const char *msg = krb5_get_error_message(context, ret);
kdc_log(context, config, 0,
"kaserver: decomp failed for %s.%s with %s %d",
msg, sname, sinstance, ret);
krb5_free_error_message(context, msg);
make_error_reply (hdr, KABADTICKET, reply);
goto out;
}
if (strcmp (sname, "krbtgt") != 0
|| strcmp (sinstance, config->v4_realm) != 0) {
kdc_log(context, config, 0, "no TGT: %s.%s for %s.%s@%s",
sname, sinstance,
ad.pname, ad.pinst, ad.prealm);
make_error_reply (hdr, KABADTICKET, reply);
free(sname);
free(sinstance);
goto out;
}
free(sname);
free(sinstance);
if (kdc_time > _krb5_krb_life_to_time(ad.time_sec, ad.life)) {
kdc_log(context, config, 0, "TGT expired: %s.%s@%s",
ad.pname, ad.pinst, ad.prealm);
make_error_reply (hdr, KABADTICKET, reply);
goto out;
}
}
snprintf (client_name, sizeof(client_name),
"%s.%s@%s", ad.pname, ad.pinst, ad.prealm);
kdc_log(context, config, 0, "TGS-REQ (kaserver) %s from %s for %s",
client_name, from, server_name);
ret = _kdc_db_fetch4 (context, config,
ad.pname, ad.pinst, ad.prealm, HDB_F_GET_CLIENT,
&client_entry);
if(ret && ret != HDB_ERR_NOENTRY) {
kdc_log(context, config, 0,
"Client not found in database: (krb4) %s: %s",
client_name, krb5_get_err_text(context, ret));
make_error_reply (hdr, KANOENT, reply);
goto out;
}
if (client_entry == NULL && strcmp(ad.prealm, config->v4_realm) == 0) {
kdc_log(context, config, 0,
"Local client not found in database: (krb4) "
"%s", client_name);
make_error_reply (hdr, KANOENT, reply);
goto out;
}
ret = kdc_check_flags (context, config,
client_entry, client_name,
server_entry, server_name,
FALSE);
if (ret) {
make_error_reply (hdr, KAPWEXPIRED, reply);
goto out;
}
/* decrypt the times */
memcpy(&session, ad.session.keyvalue.data, sizeof(session));
DES_set_key_unchecked (&session, &schedule);
DES_ecb_encrypt (times.data,
times.data,
&schedule,
DES_DECRYPT);
memset (&schedule, 0, sizeof(schedule));
memset (&session, 0, sizeof(session));
/* and extract them */
{
krb5_storage *tsp;
int32_t tmp;
tsp = krb5_storage_from_mem (times.data, times.length);
krb5_ret_int32 (tsp, &tmp);
start_time = tmp;
krb5_ret_int32 (tsp, &tmp);
end_time = tmp;
krb5_storage_free (tsp);
}
/* life */
max_life = end_time - kdc_time;
/* end_time - kdc_time can sometimes be non-positive due to slight
time skew between client and server. Let's make sure it is postive */
if(max_life < 1)
max_life = 1;
if (krbtgt_entry->entry.max_life)
max_life = min(max_life, *krbtgt_entry->entry.max_life);
if (server_entry->entry.max_life)
max_life = min(max_life, *server_entry->entry.max_life);
/* if this is a cross realm request, the client_entry will likely
be NULL */
if (client_entry && client_entry->entry.max_life)
max_life = min(max_life, *client_entry->entry.max_life);
life = _krb5_krb_time_to_life(kdc_time, kdc_time + max_life);
create_reply_ticket (context,
hdr, skey,
ad.pname, ad.pinst, ad.prealm,
addr, life, server_entry->entry.kvno,
max_seq_len,
name, instance,
0, "gtkt",
&ad.session, reply);
out:
_krb5_krb_free_auth_data(context, &ad);
if (aticket.length) {
memset (aticket.data, 0, aticket.length);
krb5_data_free (&aticket);
}
if (times.length) {
memset (times.data, 0, times.length);
krb5_data_free (×);
}
if (auth_domain)
free (auth_domain);
if (name)
free (name);
if (instance)
free (instance);
if (krbtgt_entry)
_kdc_free_ent (context, krbtgt_entry);
if (server_entry)
_kdc_free_ent (context, server_entry);
}
static krb5_error_code
encode_524_response(krb5_context context,
krb5_kdc_configuration *config,
const char *spn, const EncTicketPart et,
const Ticket *t, hdb_entry_ex *server,
EncryptedData *ticket, int *kvno)
{
krb5_error_code ret;
int use_2b;
size_t len;
use_2b = krb5_config_get_bool(context, NULL, "kdc", "use_2b", spn, NULL);
if(use_2b) {
ASN1_MALLOC_ENCODE(EncryptedData,
ticket->cipher.data, ticket->cipher.length,
&t->enc_part, &len, ret);
if (ret) {
kdc_log(context, config, 0,
"Failed to encode v4 (2b) ticket (%s)", spn);
return ret;
}
ticket->etype = 0;
ticket->kvno = NULL;
*kvno = 213; /* 2b's use this magic kvno */
} else {
unsigned char buf[MAX_KTXT_LEN + 4 * 4];
Key *skey;
if (!config->enable_v4_cross_realm && strcmp (et.crealm, t->realm) != 0) {
kdc_log(context, config, 0, "524 cross-realm %s -> %s disabled", et.crealm,
t->realm);
return KRB5KDC_ERR_POLICY;
}
ret = _kdc_encode_v4_ticket(context, config,
buf + sizeof(buf) - 1, sizeof(buf),
&et, &t->sname, &len);
if(ret){
kdc_log(context, config, 0,
"Failed to encode v4 ticket (%s)", spn);
return ret;
}
ret = _kdc_get_des_key(context, server, TRUE, FALSE, &skey);
if(ret){
kdc_log(context, config, 0,
"no suitable DES key for server (%s)", spn);
return ret;
}
ret = encrypt_v4_ticket(context, config, buf + sizeof(buf) - len, len,
&skey->key, ticket);
if(ret){
kdc_log(context, config, 0,
"Failed to encrypt v4 ticket (%s)", spn);
return ret;
}
*kvno = server->entry.kvno;
}
return 0;
}
static void
do_authenticate (krb5_context context,
krb5_kdc_configuration *config,
struct rx_header *hdr,
krb5_storage *sp,
struct sockaddr_in *addr,
const char *from,
krb5_data *reply)
{
krb5_error_code ret;
char *name = NULL;
char *instance = NULL;
time_t start_time;
time_t end_time;
krb5_data request;
int32_t max_seq_len;
hdb_entry_ex *client_entry = NULL;
hdb_entry_ex *server_entry = NULL;
Key *ckey = NULL;
Key *skey = NULL;
krb5_storage *reply_sp;
time_t max_life;
uint8_t life;
int32_t chal;
char client_name[256];
char server_name[256];
krb5_data_zero (&request);
ret = unparse_auth_args (sp, &name, &instance, &start_time, &end_time,
&request, &max_seq_len);
if (ret != 0 || request.length < 8) {
make_error_reply (hdr, KABADREQUEST, reply);
goto out;
}
snprintf (client_name, sizeof(client_name), "%s.%s@%s",
name, instance, config->v4_realm);
snprintf (server_name, sizeof(server_name), "%s.%s@%s",
"krbtgt", config->v4_realm, config->v4_realm);
kdc_log(context, config, 0, "AS-REQ (kaserver) %s from %s for %s",
client_name, from, server_name);
ret = _kdc_db_fetch4 (context, config, name, instance,
config->v4_realm, HDB_F_GET_CLIENT,
&client_entry);
if (ret) {
kdc_log(context, config, 0, "Client not found in database: %s: %s",
client_name, krb5_get_err_text(context, ret));
make_error_reply (hdr, KANOENT, reply);
goto out;
}
ret = _kdc_db_fetch4 (context, config, "krbtgt",
config->v4_realm, config->v4_realm,
HDB_F_GET_KRBTGT, &server_entry);
if (ret) {
kdc_log(context, config, 0, "Server not found in database: %s: %s",
server_name, krb5_get_err_text(context, ret));
make_error_reply (hdr, KANOENT, reply);
goto out;
}
ret = kdc_check_flags (context, config,
client_entry, client_name,
server_entry, server_name,
TRUE);
if (ret) {
make_error_reply (hdr, KAPWEXPIRED, reply);
goto out;
}
/* find a DES key */
ret = _kdc_get_des_key(context, client_entry, FALSE, TRUE, &ckey);
if(ret){
kdc_log(context, config, 0, "no suitable DES key for client");
make_error_reply (hdr, KANOKEYS, reply);
goto out;
}
/* find a DES key */
ret = _kdc_get_des_key(context, server_entry, TRUE, TRUE, &skey);
if(ret){
kdc_log(context, config, 0, "no suitable DES key for server");
make_error_reply (hdr, KANOKEYS, reply);
goto out;
}
{
DES_cblock key;
DES_key_schedule schedule;
/* try to decode the `request' */
memcpy (&key, ckey->key.keyvalue.data, sizeof(key));
DES_set_key_unchecked (&key, &schedule);
DES_pcbc_encrypt (request.data,
request.data,
request.length,
&schedule,
&key,
DES_DECRYPT);
memset (&schedule, 0, sizeof(schedule));
memset (&key, 0, sizeof(key));
}
/* check for the magic label */
if (memcmp ((char *)request.data + 4, "gTGS", 4) != 0) {
kdc_log(context, config, 0, "preauth failed for %s", client_name);
make_error_reply (hdr, KABADREQUEST, reply);
goto out;
}
reply_sp = krb5_storage_from_mem (request.data, 4);
krb5_ret_int32 (reply_sp, &chal);
krb5_storage_free (reply_sp);
if (abs(chal - kdc_time) > context->max_skew) {
make_error_reply (hdr, KACLOCKSKEW, reply);
goto out;
}
/* life */
max_life = end_time - kdc_time;
/* end_time - kdc_time can sometimes be non-positive due to slight
time skew between client and server. Let's make sure it is postive */
if(max_life < 1)
max_life = 1;
if (client_entry->entry.max_life)
max_life = min(max_life, *client_entry->entry.max_life);
if (server_entry->entry.max_life)
max_life = min(max_life, *server_entry->entry.max_life);
life = krb_time_to_life(kdc_time, kdc_time + max_life);
create_reply_ticket (context,
hdr, skey,
name, instance, config->v4_realm,
addr, life, server_entry->entry.kvno,
max_seq_len,
"krbtgt", config->v4_realm,
chal + 1, "tgsT",
&ckey->key, reply);
out:
if (request.length) {
memset (request.data, 0, request.length);
krb5_data_free (&request);
}
if (name)
free (name);
if (instance)
free (instance);
if (client_entry)
_kdc_free_ent (context, client_entry);
if (server_entry)
_kdc_free_ent (context, server_entry);
}
