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freebsd/crypto/heimdal/kdc/kaserver.c
2003-10-09 19:36:20 +00:00

831 lines
22 KiB
C

/*
* Copyright (c) 1997 - 2002 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. 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: kaserver.c,v 1.21 2002/10/21 12:59:41 joda Exp $");
#include <rx.h>
#define KA_AUTHENTICATION_SERVICE 731
#define KA_TICKET_GRANTING_SERVICE 732
#define KA_MAINTENANCE_SERVICE 733
#define AUTHENTICATE_OLD 1
#define CHANGEPASSWORD 2
#define GETTICKET_OLD 3
#define SETPASSWORD 4
#define SETFIELDS 5
#define CREATEUSER 6
#define DELETEUSER 7
#define GETENTRY 8
#define LISTENTRY 9
#define GETSTATS 10
#define DEBUG 11
#define GETPASSWORD 12
#define GETRANDOMKEY 13
#define AUTHENTICATE 21
#define AUTHENTICATE_V2 22
#define GETTICKET 23
/* XXX - Where do we get these? */
#define RXGEN_OPCODE (-455)
#define KADATABASEINCONSISTENT (180480L)
#define KAEXIST (180481L)
#define KAIO (180482L)
#define KACREATEFAIL (180483L)
#define KANOENT (180484L)
#define KAEMPTY (180485L)
#define KABADNAME (180486L)
#define KABADINDEX (180487L)
#define KANOAUTH (180488L)
#define KAANSWERTOOLONG (180489L)
#define KABADREQUEST (180490L)
#define KAOLDINTERFACE (180491L)
#define KABADARGUMENT (180492L)
#define KABADCMD (180493L)
#define KANOKEYS (180494L)
#define KAREADPW (180495L)
#define KABADKEY (180496L)
#define KAUBIKINIT (180497L)
#define KAUBIKCALL (180498L)
#define KABADPROTOCOL (180499L)
#define KANOCELLS (180500L)
#define KANOCELL (180501L)
#define KATOOMANYUBIKS (180502L)
#define KATOOMANYKEYS (180503L)
#define KABADTICKET (180504L)
#define KAUNKNOWNKEY (180505L)
#define KAKEYCACHEINVALID (180506L)
#define KABADSERVER (180507L)
#define KABADUSER (180508L)
#define KABADCPW (180509L)
#define KABADCREATE (180510L)
#define KANOTICKET (180511L)
#define KAASSOCUSER (180512L)
#define KANOTSPECIAL (180513L)
#define KACLOCKSKEW (180514L)
#define KANORECURSE (180515L)
#define KARXFAIL (180516L)
#define KANULLPASSWORD (180517L)
#define KAINTERNALERROR (180518L)
#define KAPWEXPIRED (180519L)
#define KAREUSED (180520L)
#define KATOOSOON (180521L)
#define KALOCKED (180522L)
static void
decode_rx_header (krb5_storage *sp,
struct rx_header *h)
{
krb5_ret_int32(sp, &h->epoch);
krb5_ret_int32(sp, &h->connid);
krb5_ret_int32(sp, &h->callid);
krb5_ret_int32(sp, &h->seqno);
krb5_ret_int32(sp, &h->serialno);
krb5_ret_int8(sp, &h->type);
krb5_ret_int8(sp, &h->flags);
krb5_ret_int8(sp, &h->status);
krb5_ret_int8(sp, &h->secindex);
krb5_ret_int16(sp, &h->reserved);
krb5_ret_int16(sp, &h->serviceid);
}
static void
encode_rx_header (struct rx_header *h,
krb5_storage *sp)
{
krb5_store_int32(sp, h->epoch);
krb5_store_int32(sp, h->connid);
krb5_store_int32(sp, h->callid);
krb5_store_int32(sp, h->seqno);
krb5_store_int32(sp, h->serialno);
krb5_store_int8(sp, h->type);
krb5_store_int8(sp, h->flags);
krb5_store_int8(sp, h->status);
krb5_store_int8(sp, h->secindex);
krb5_store_int16(sp, h->reserved);
krb5_store_int16(sp, h->serviceid);
}
static void
init_reply_header (struct rx_header *hdr,
struct rx_header *reply_hdr,
u_char type,
u_char flags)
{
reply_hdr->epoch = hdr->epoch;
reply_hdr->connid = hdr->connid;
reply_hdr->callid = hdr->callid;
reply_hdr->seqno = 1;
reply_hdr->serialno = 1;
reply_hdr->type = type;
reply_hdr->flags = flags;
reply_hdr->status = 0;
reply_hdr->secindex = 0;
reply_hdr->reserved = 0;
reply_hdr->serviceid = hdr->serviceid;
}
static void
make_error_reply (struct rx_header *hdr,
u_int32_t ret,
krb5_data *reply)
{
krb5_storage *sp;
struct rx_header reply_hdr;
init_reply_header (hdr, &reply_hdr, HT_ABORT, HF_LAST);
sp = krb5_storage_emem();
encode_rx_header (&reply_hdr, sp);
krb5_store_int32(sp, ret);
krb5_storage_to_data (sp, reply);
krb5_storage_free (sp);
}
static krb5_error_code
krb5_ret_xdr_data(krb5_storage *sp,
krb5_data *data)
{
int ret;
int size;
ret = krb5_ret_int32(sp, &size);
if(ret)
return ret;
if(size < 0)
return ERANGE;
data->length = size;
if (size) {
u_char foo[4];
size_t pad = (4 - size % 4) % 4;
data->data = malloc(size);
if (data->data == NULL)
return ENOMEM;
ret = krb5_storage_read(sp, data->data, size);
if(ret != size)
return (ret < 0)? errno : KRB5_CC_END;
if (pad) {
ret = krb5_storage_read(sp, foo, pad);
if (ret != pad)
return (ret < 0)? errno : KRB5_CC_END;
}
} else
data->data = NULL;
return 0;
}
static krb5_error_code
krb5_store_xdr_data(krb5_storage *sp,
krb5_data data)
{
u_char zero[4] = {0, 0, 0, 0};
int ret;
size_t pad;
ret = krb5_store_int32(sp, data.length);
if(ret < 0)
return ret;
ret = krb5_storage_write(sp, data.data, data.length);
if(ret != data.length){
if(ret < 0)
return errno;
return KRB5_CC_END;
}
pad = (4 - data.length % 4) % 4;
if (pad) {
ret = krb5_storage_write(sp, zero, pad);
if (ret != pad) {
if (ret < 0)
return errno;
return KRB5_CC_END;
}
}
return 0;
}
static krb5_error_code
create_reply_ticket (struct rx_header *hdr,
Key *skey,
char *name, char *instance, char *realm,
struct sockaddr_in *addr,
int life,
int kvno,
int32_t max_seq_len,
const char *sname, const char *sinstance,
u_int32_t challenge,
const char *label,
des_cblock *key,
krb5_data *reply)
{
KTEXT_ST ticket;
des_cblock session;
krb5_storage *sp;
krb5_data enc_data;
des_key_schedule schedule;
struct rx_header reply_hdr;
des_cblock zero;
size_t pad;
unsigned fyrtiosjuelva;
/* create the ticket */
des_new_random_key(&session);
krb_create_ticket (&ticket, 0, name, instance, realm,
addr->sin_addr.s_addr,
&session, life, kdc_time,
sname, sinstance, skey->key.keyvalue.data);
/* create the encrypted part of the reply */
sp = krb5_storage_emem ();
krb5_generate_random_block(&fyrtiosjuelva, sizeof(fyrtiosjuelva));
fyrtiosjuelva &= 0xffffffff;
krb5_store_int32 (sp, fyrtiosjuelva);
krb5_store_int32 (sp, challenge);
krb5_storage_write (sp, session, 8);
memset (&session, 0, sizeof(session));
krb5_store_int32 (sp, kdc_time);
krb5_store_int32 (sp, kdc_time + krb_life_to_time (0, life));
krb5_store_int32 (sp, kvno);
krb5_store_int32 (sp, ticket.length);
krb5_store_stringz (sp, name);
krb5_store_stringz (sp, instance);
#if 1 /* XXX - Why shouldn't the realm go here? */
krb5_store_stringz (sp, "");
#else
krb5_store_stringz (sp, realm);
#endif
krb5_store_stringz (sp, sname);
krb5_store_stringz (sp, sinstance);
krb5_storage_write (sp, ticket.dat, ticket.length);
krb5_storage_write (sp, label, strlen(label));
/* pad to DES block */
memset (zero, 0, sizeof(zero));
pad = (8 - krb5_storage_seek (sp, 0, SEEK_CUR) % 8) % 8;
krb5_storage_write (sp, zero, pad);
krb5_storage_to_data (sp, &enc_data);
krb5_storage_free (sp);
if (enc_data.length > max_seq_len) {
krb5_data_free (&enc_data);
make_error_reply (hdr, KAANSWERTOOLONG, reply);
return 0;
}
/* encrypt it */
des_set_key (key, schedule);
des_pcbc_encrypt (enc_data.data,
enc_data.data,
enc_data.length,
schedule,
key,
DES_ENCRYPT);
memset (&schedule, 0, sizeof(schedule));
/* create the reply packet */
init_reply_header (hdr, &reply_hdr, HT_DATA, HF_LAST);
sp = krb5_storage_emem ();
encode_rx_header (&reply_hdr, sp);
krb5_store_int32 (sp, max_seq_len);
krb5_store_xdr_data (sp, enc_data);
krb5_data_free (&enc_data);
krb5_storage_to_data (sp, reply);
krb5_storage_free (sp);
return 0;
}
static krb5_error_code
unparse_auth_args (krb5_storage *sp,
char **name,
char **instance,
time_t *start_time,
time_t *end_time,
krb5_data *request,
int32_t *max_seq_len)
{
krb5_data data;
int32_t tmp;
krb5_ret_xdr_data (sp, &data);
*name = malloc(data.length + 1);
if (*name == NULL)
return ENOMEM;
memcpy (*name, data.data, data.length);
(*name)[data.length] = '\0';
krb5_data_free (&data);
krb5_ret_xdr_data (sp, &data);
*instance = malloc(data.length + 1);
if (*instance == NULL) {
free (*name);
return ENOMEM;
}
memcpy (*instance, data.data, data.length);
(*instance)[data.length] = '\0';
krb5_data_free (&data);
krb5_ret_int32 (sp, &tmp);
*start_time = tmp;
krb5_ret_int32 (sp, &tmp);
*end_time = tmp;
krb5_ret_xdr_data (sp, request);
krb5_ret_int32 (sp, max_seq_len);
/* ignore the rest */
return 0;
}
static void
do_authenticate (struct rx_header *hdr,
krb5_storage *sp,
struct sockaddr_in *addr,
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 *client_entry = NULL;
hdb_entry *server_entry = NULL;
Key *ckey = NULL;
Key *skey = NULL;
des_cblock key;
des_key_schedule schedule;
krb5_storage *reply_sp;
time_t max_life;
u_int8_t life;
int32_t chal;
char client_name[256];
char server_name[256];
krb5_data_zero (&request);
unparse_auth_args (sp, &name, &instance, &start_time, &end_time,
&request, &max_seq_len);
snprintf (client_name, sizeof(client_name), "%s.%s@%s",
name, instance, v4_realm);
ret = db_fetch4 (name, instance, v4_realm, &client_entry);
if (ret) {
kdc_log(0, "Client not found in database: %s: %s",
client_name, krb5_get_err_text(context, ret));
make_error_reply (hdr, KANOENT, reply);
goto out;
}
snprintf (server_name, sizeof(server_name), "%s.%s@%s",
"krbtgt", v4_realm, v4_realm);
ret = db_fetch4 ("krbtgt", v4_realm, v4_realm, &server_entry);
if (ret) {
kdc_log(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 = check_flags (client_entry, client_name,
server_entry, server_name,
TRUE);
if (ret) {
make_error_reply (hdr, KAPWEXPIRED, reply);
goto out;
}
/* find a DES key */
ret = get_des_key(client_entry, FALSE, TRUE, &ckey);
if(ret){
kdc_log(0, "no suitable DES key for client");
make_error_reply (hdr, KANOKEYS, reply);
goto out;
}
/* find a DES key */
ret = get_des_key(server_entry, TRUE, TRUE, &skey);
if(ret){
kdc_log(0, "no suitable DES key for server");
make_error_reply (hdr, KANOKEYS, reply);
goto out;
}
/* try to decode the `request' */
memcpy (&key, ckey->key.keyvalue.data, sizeof(key));
des_set_key (&key, schedule);
des_pcbc_encrypt (request.data,
request.data,
request.length,
schedule,
&key,
DES_DECRYPT);
memset (&schedule, 0, sizeof(schedule));
/* check for the magic label */
if (memcmp ((char *)request.data + 4, "gTGS", 4) != 0) {
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->max_life)
max_life = min(max_life, *client_entry->max_life);
if (server_entry->max_life)
max_life = min(max_life, *server_entry->max_life);
life = krb_time_to_life(kdc_time, kdc_time + max_life);
create_reply_ticket (hdr, skey,
name, instance, v4_realm,
addr, life, server_entry->kvno,
max_seq_len,
"krbtgt", v4_realm,
chal + 1, "tgsT",
&key, reply);
memset (&key, 0, sizeof(key));
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)
free_ent (client_entry);
if (server_entry)
free_ent (server_entry);
}
static krb5_error_code
unparse_getticket_args (krb5_storage *sp,
int *kvno,
char **auth_domain,
krb5_data *ticket,
char **name,
char **instance,
krb5_data *times,
int32_t *max_seq_len)
{
krb5_data data;
int32_t tmp;
krb5_ret_int32 (sp, &tmp);
*kvno = tmp;
krb5_ret_xdr_data (sp, &data);
*auth_domain = malloc(data.length + 1);
if (*auth_domain == NULL)
return ENOMEM;
memcpy (*auth_domain, data.data, data.length);
(*auth_domain)[data.length] = '\0';
krb5_data_free (&data);
krb5_ret_xdr_data (sp, ticket);
krb5_ret_xdr_data (sp, &data);
*name = malloc(data.length + 1);
if (*name == NULL) {
free (*auth_domain);
return ENOMEM;
}
memcpy (*name, data.data, data.length);
(*name)[data.length] = '\0';
krb5_data_free (&data);
krb5_ret_xdr_data (sp, &data);
*instance = malloc(data.length + 1);
if (*instance == NULL) {
free (*auth_domain);
free (*name);
return ENOMEM;
}
memcpy (*instance, data.data, data.length);
(*instance)[data.length] = '\0';
krb5_data_free (&data);
krb5_ret_xdr_data (sp, times);
krb5_ret_int32 (sp, max_seq_len);
/* ignore the rest */
return 0;
}
static void
do_getticket (struct rx_header *hdr,
krb5_storage *sp,
struct sockaddr_in *addr,
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 *server_entry = NULL;
hdb_entry *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 pname[ANAME_SZ];
char pinst[INST_SZ];
char prealm[REALM_SZ];
char server_name[256];
krb5_data_zero (&aticket);
krb5_data_zero (&times);
unparse_getticket_args (sp, &kvno, &auth_domain, &aticket,
&name, &instance, &times, &max_seq_len);
snprintf (server_name, sizeof(server_name),
"%s.%s@%s", name, instance, v4_realm);
ret = db_fetch4 (name, instance, v4_realm, &server_entry);
if (ret) {
kdc_log(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 = check_flags (NULL, NULL,
server_entry, server_name,
FALSE);
if (ret) {
make_error_reply (hdr, KAPWEXPIRED, reply);
goto out;
}
ret = db_fetch4 ("krbtgt", v4_realm, v4_realm, &krbtgt_entry);
if (ret) {
kdc_log(0, "Server not found in database: %s.%s@%s: %s",
"krbtgt", v4_realm, v4_realm, krb5_get_err_text(context, ret));
make_error_reply (hdr, KANOENT, reply);
goto out;
}
/* find a DES key */
ret = get_des_key(krbtgt_entry, TRUE, TRUE, &kkey);
if(ret){
kdc_log(0, "no suitable DES key for krbtgt");
make_error_reply (hdr, KANOKEYS, reply);
goto out;
}
/* find a DES key */
ret = get_des_key(server_entry, TRUE, TRUE, &skey);
if(ret){
kdc_log(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 */
{
KTEXT_ST ticket;
u_char flags;
int life;
u_int32_t time_sec;
char sname[ANAME_SZ];
char sinstance[SNAME_SZ];
u_int32_t paddress;
if (aticket.length > sizeof(ticket.dat)) {
kdc_log(0, "ticket too long (%u > %u)",
(unsigned)aticket.length,
(unsigned)sizeof(ticket.dat));
make_error_reply (hdr, KABADTICKET, reply);
goto out;
}
ticket.length = aticket.length;
memcpy (ticket.dat, aticket.data, ticket.length);
des_set_key (&key, schedule);
decomp_ticket (&ticket, &flags, pname, pinst, prealm,
&paddress, session, &life, &time_sec,
sname, sinstance,
&key, schedule);
if (strcmp (sname, "krbtgt") != 0
|| strcmp (sinstance, v4_realm) != 0) {
kdc_log(0, "no TGT: %s.%s for %s.%s@%s",
sname, sinstance,
pname, pinst, prealm);
make_error_reply (hdr, KABADTICKET, reply);
goto out;
}
if (kdc_time > krb_life_to_time(time_sec, life)) {
kdc_log(0, "TGT expired: %s.%s@%s",
pname, pinst, prealm);
make_error_reply (hdr, KABADTICKET, reply);
goto out;
}
}
/* decrypt the times */
des_set_key (&session, schedule);
des_ecb_encrypt (times.data,
times.data,
schedule,
DES_DECRYPT);
memset (&schedule, 0, sizeof(schedule));
/* and extract them */
{
krb5_storage *sp;
int32_t tmp;
sp = krb5_storage_from_mem (times.data, times.length);
krb5_ret_int32 (sp, &tmp);
start_time = tmp;
krb5_ret_int32 (sp, &tmp);
end_time = tmp;
krb5_storage_free (sp);
}
/* 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->max_life)
max_life = min(max_life, *krbtgt_entry->max_life);
if (server_entry->max_life)
max_life = min(max_life, *server_entry->max_life);
life = krb_time_to_life(kdc_time, kdc_time + max_life);
create_reply_ticket (hdr, skey,
pname, pinst, prealm,
addr, life, server_entry->kvno,
max_seq_len,
name, instance,
0, "gtkt",
&session, reply);
memset (&session, 0, sizeof(session));
out:
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 (&times);
}
if (auth_domain)
free (auth_domain);
if (name)
free (name);
if (instance)
free (instance);
if (krbtgt_entry)
free_ent (krbtgt_entry);
if (server_entry)
free_ent (server_entry);
}
krb5_error_code
do_kaserver(unsigned char *buf,
size_t len,
krb5_data *reply,
const char *from,
struct sockaddr_in *addr)
{
krb5_error_code ret = 0;
struct rx_header hdr;
u_int32_t op;
krb5_storage *sp;
if (len < RX_HEADER_SIZE)
return -1;
sp = krb5_storage_from_mem (buf, len);
decode_rx_header (sp, &hdr);
buf += RX_HEADER_SIZE;
len -= RX_HEADER_SIZE;
switch (hdr.type) {
case HT_DATA :
break;
case HT_ACK :
case HT_BUSY :
case HT_ABORT :
case HT_ACKALL :
case HT_CHAL :
case HT_RESP :
case HT_DEBUG :
default:
/* drop */
goto out;
}
if (hdr.serviceid != KA_AUTHENTICATION_SERVICE
&& hdr.serviceid != KA_TICKET_GRANTING_SERVICE) {
ret = -1;
goto out;
}
krb5_ret_int32(sp, &op);
switch (op) {
case AUTHENTICATE :
do_authenticate (&hdr, sp, addr, reply);
break;
case GETTICKET :
do_getticket (&hdr, sp, addr, reply);
break;
case AUTHENTICATE_OLD :
case CHANGEPASSWORD :
case GETTICKET_OLD :
case SETPASSWORD :
case SETFIELDS :
case CREATEUSER :
case DELETEUSER :
case GETENTRY :
case LISTENTRY :
case GETSTATS :
case DEBUG :
case GETPASSWORD :
case GETRANDOMKEY :
case AUTHENTICATE_V2 :
default :
make_error_reply (&hdr, RXGEN_OPCODE, reply);
break;
}
out:
krb5_storage_free (sp);
return ret;
}