OpenBSD-4.6/kerberosV/src/lib/krb5/get_in_tkt.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 "krb5_locl.h"
RCSID("$KTH: get_in_tkt.c,v 1.115 2004/12/29 18:55:14 lha Exp $");
krb5_error_code KRB5_LIB_FUNCTION
krb5_init_etype (krb5_context context,
unsigned *len,
krb5_enctype **val,
const krb5_enctype *etypes)
{
int i;
krb5_error_code ret;
krb5_enctype *tmp = NULL;
ret = 0;
if (etypes == NULL) {
ret = krb5_get_default_in_tkt_etypes(context,
&tmp);
if (ret)
return ret;
etypes = tmp;
}
for (i = 0; etypes[i]; ++i)
;
*len = i;
*val = malloc(i * sizeof(**val));
if (i != 0 && *val == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto cleanup;
}
memmove (*val,
etypes,
i * sizeof(*tmp));
cleanup:
if (tmp != NULL)
free (tmp);
return ret;
}
static krb5_error_code
decrypt_tkt (krb5_context context,
krb5_keyblock *key,
krb5_key_usage usage,
krb5_const_pointer decrypt_arg,
krb5_kdc_rep *dec_rep)
{
krb5_error_code ret;
krb5_data data;
size_t size;
krb5_crypto crypto;
ret = krb5_crypto_init(context, key, 0, &crypto);
if (ret)
return ret;
ret = krb5_decrypt_EncryptedData (context,
crypto,
usage,
&dec_rep->kdc_rep.enc_part,
&data);
krb5_crypto_destroy(context, crypto);
if (ret)
return ret;
ret = krb5_decode_EncASRepPart(context,
data.data,
data.length,
&dec_rep->enc_part,
&size);
if (ret)
ret = krb5_decode_EncTGSRepPart(context,
data.data,
data.length,
&dec_rep->enc_part,
&size);
krb5_data_free (&data);
if (ret)
return ret;
return 0;
}
int
_krb5_extract_ticket(krb5_context context,
krb5_kdc_rep *rep,
krb5_creds *creds,
krb5_keyblock *key,
krb5_const_pointer keyseed,
krb5_key_usage key_usage,
krb5_addresses *addrs,
unsigned nonce,
krb5_boolean allow_server_mismatch,
krb5_boolean ignore_cname,
krb5_decrypt_proc decrypt_proc,
krb5_const_pointer decryptarg)
{
krb5_error_code ret;
krb5_principal tmp_principal;
int tmp;
size_t len;
time_t tmp_time;
krb5_timestamp sec_now;
ret = _krb5_principalname2krb5_principal (&tmp_principal,
rep->kdc_rep.cname,
rep->kdc_rep.crealm);
if (ret)
goto out;
/* compare client */
if (!ignore_cname) {
tmp = krb5_principal_compare (context, tmp_principal, creds->client);
if (!tmp) {
krb5_free_principal (context, tmp_principal);
krb5_clear_error_string (context);
ret = KRB5KRB_AP_ERR_MODIFIED;
goto out;
}
}
krb5_free_principal (context, creds->client);
creds->client = tmp_principal;
/* extract ticket */
ASN1_MALLOC_ENCODE(Ticket, creds->ticket.data, creds->ticket.length,
&rep->kdc_rep.ticket, &len, ret);
if(ret)
goto out;
if (creds->ticket.length != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
creds->second_ticket.length = 0;
creds->second_ticket.data = NULL;
/* compare server */
ret = _krb5_principalname2krb5_principal (&tmp_principal,
rep->kdc_rep.ticket.sname,
rep->kdc_rep.ticket.realm);
if (ret)
goto out;
if(allow_server_mismatch){
krb5_free_principal(context, creds->server);
creds->server = tmp_principal;
tmp_principal = NULL;
}else{
tmp = krb5_principal_compare (context, tmp_principal, creds->server);
krb5_free_principal (context, tmp_principal);
if (!tmp) {
ret = KRB5KRB_AP_ERR_MODIFIED;
krb5_clear_error_string (context);
goto out;
}
}
/* decrypt */
if (decrypt_proc == NULL)
decrypt_proc = decrypt_tkt;
ret = (*decrypt_proc)(context, key, key_usage, decryptarg, rep);
if (ret)
goto out;
#if 0
/* XXX should this decode be here, or in the decrypt_proc? */
ret = krb5_decode_keyblock(context, &rep->enc_part.key, 1);
if(ret)
goto out;
#endif
/* compare nonces */
if (nonce != rep->enc_part.nonce) {
ret = KRB5KRB_AP_ERR_MODIFIED;
krb5_set_error_string(context, "malloc: out of memory");
goto out;
}
/* set kdc-offset */
krb5_timeofday (context, &sec_now);
if (rep->enc_part.flags.initial
&& context->kdc_sec_offset == 0
&& krb5_config_get_bool (context, NULL,
"libdefaults",
"kdc_timesync",
NULL)) {
context->kdc_sec_offset = rep->enc_part.authtime - sec_now;
krb5_timeofday (context, &sec_now);
}
/* check all times */
if (rep->enc_part.starttime) {
tmp_time = *rep->enc_part.starttime;
} else
tmp_time = rep->enc_part.authtime;
if (creds->times.starttime == 0
&& abs(tmp_time - sec_now) > context->max_skew) {
ret = KRB5KRB_AP_ERR_SKEW;
krb5_set_error_string (context,
"time skew (%d) larger than max (%d)",
abs(tmp_time - sec_now),
(int)context->max_skew);
goto out;
}
if (creds->times.starttime != 0
&& tmp_time != creds->times.starttime) {
krb5_clear_error_string (context);
ret = KRB5KRB_AP_ERR_MODIFIED;
goto out;
}
creds->times.starttime = tmp_time;
if (rep->enc_part.renew_till) {
tmp_time = *rep->enc_part.renew_till;
} else
tmp_time = 0;
if (creds->times.renew_till != 0
&& tmp_time > creds->times.renew_till) {
krb5_clear_error_string (context);
ret = KRB5KRB_AP_ERR_MODIFIED;
goto out;
}
creds->times.renew_till = tmp_time;
creds->times.authtime = rep->enc_part.authtime;
if (creds->times.endtime != 0
&& rep->enc_part.endtime > creds->times.endtime) {
krb5_clear_error_string (context);
ret = KRB5KRB_AP_ERR_MODIFIED;
goto out;
}
creds->times.endtime = rep->enc_part.endtime;
if(rep->enc_part.caddr)
krb5_copy_addresses (context, rep->enc_part.caddr, &creds->addresses);
else if(addrs)
krb5_copy_addresses (context, addrs, &creds->addresses);
else {
creds->addresses.len = 0;
creds->addresses.val = NULL;
}
creds->flags.b = rep->enc_part.flags;
creds->authdata.len = 0;
creds->authdata.val = NULL;
creds->session.keyvalue.length = 0;
creds->session.keyvalue.data = NULL;
creds->session.keytype = rep->enc_part.key.keytype;
ret = krb5_data_copy (&creds->session.keyvalue,
rep->enc_part.key.keyvalue.data,
rep->enc_part.key.keyvalue.length);
out:
memset (rep->enc_part.key.keyvalue.data, 0,
rep->enc_part.key.keyvalue.length);
return ret;
}
static krb5_error_code
make_pa_enc_timestamp(krb5_context context, PA_DATA *pa,
krb5_enctype etype, krb5_keyblock *key)
{
PA_ENC_TS_ENC p;
unsigned char *buf;
size_t buf_size;
size_t len;
EncryptedData encdata;
krb5_error_code ret;
int32_t usec;
int usec2;
krb5_crypto crypto;
krb5_us_timeofday (context, &p.patimestamp, &usec);
usec2 = usec;
p.pausec = &usec2;
ASN1_MALLOC_ENCODE(PA_ENC_TS_ENC, buf, buf_size, &p, &len, ret);
if (ret)
return ret;
if(buf_size != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
ret = krb5_crypto_init(context, key, 0, &crypto);
if (ret) {
free(buf);
return ret;
}
ret = krb5_encrypt_EncryptedData(context,
crypto,
KRB5_KU_PA_ENC_TIMESTAMP,
buf,
len,
0,
&encdata);
free(buf);
krb5_crypto_destroy(context, crypto);
if (ret)
return ret;
ASN1_MALLOC_ENCODE(EncryptedData, buf, buf_size, &encdata, &len, ret);
free_EncryptedData(&encdata);
if (ret)
return ret;
if(buf_size != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
pa->padata_type = KRB5_PADATA_ENC_TIMESTAMP;
pa->padata_value.length = len;
pa->padata_value.data = buf;
return 0;
}
static krb5_error_code
add_padata(krb5_context context,
METHOD_DATA *md,
krb5_principal client,
krb5_key_proc key_proc,
krb5_const_pointer keyseed,
krb5_enctype *enctypes,
unsigned netypes,
krb5_salt *salt)
{
krb5_error_code ret;
PA_DATA *pa2;
krb5_salt salt2;
krb5_enctype *ep;
int i;
if(salt == NULL) {
/* default to standard salt */
ret = krb5_get_pw_salt (context, client, &salt2);
salt = &salt2;
}
if (!enctypes) {
enctypes = context->etypes;
netypes = 0;
for (ep = enctypes; *ep != ETYPE_NULL; ep++)
netypes++;
}
pa2 = realloc (md->val, (md->len + netypes) * sizeof(*md->val));
if (pa2 == NULL) {
krb5_set_error_string(context, "malloc: out of memory");
return ENOMEM;
}
md->val = pa2;
for (i = 0; i < netypes; ++i) {
krb5_keyblock *key;
ret = (*key_proc)(context, enctypes[i], *salt, keyseed, &key);
if (ret)
continue;
ret = make_pa_enc_timestamp (context, &md->val[md->len],
enctypes[i], key);
krb5_free_keyblock (context, key);
if (ret)
return ret;
++md->len;
}
if(salt == &salt2)
krb5_free_salt(context, salt2);
return 0;
}
static krb5_error_code
init_as_req (krb5_context context,
krb5_kdc_flags opts,
krb5_creds *creds,
const krb5_addresses *addrs,
const krb5_enctype *etypes,
const krb5_preauthtype *ptypes,
const krb5_preauthdata *preauth,
krb5_key_proc key_proc,
krb5_const_pointer keyseed,
unsigned nonce,
AS_REQ *a)
{
krb5_error_code ret;
krb5_salt salt;
memset(a, 0, sizeof(*a));
a->pvno = 5;
a->msg_type = krb_as_req;
a->req_body.kdc_options = opts.b;
a->req_body.cname = malloc(sizeof(*a->req_body.cname));
if (a->req_body.cname == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
a->req_body.sname = malloc(sizeof(*a->req_body.sname));
if (a->req_body.sname == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
ret = _krb5_principal2principalname (a->req_body.cname, creds->client);
if (ret)
goto fail;
ret = _krb5_principal2principalname (a->req_body.sname, creds->server);
if (ret)
goto fail;
ret = copy_Realm(&creds->client->realm, &a->req_body.realm);
if (ret)
goto fail;
if(creds->times.starttime) {
a->req_body.from = malloc(sizeof(*a->req_body.from));
if (a->req_body.from == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
*a->req_body.from = creds->times.starttime;
}
if(creds->times.endtime){
ALLOC(a->req_body.till, 1);
*a->req_body.till = creds->times.endtime;
}
if(creds->times.renew_till){
a->req_body.rtime = malloc(sizeof(*a->req_body.rtime));
if (a->req_body.rtime == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
*a->req_body.rtime = creds->times.renew_till;
}
a->req_body.nonce = nonce;
ret = krb5_init_etype (context,
&a->req_body.etype.len,
&a->req_body.etype.val,
etypes);
if (ret)
goto fail;
/*
* This means no addresses
*/
if (addrs && addrs->len == 0) {
a->req_body.addresses = NULL;
} else {
a->req_body.addresses = malloc(sizeof(*a->req_body.addresses));
if (a->req_body.addresses == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
if (addrs)
ret = krb5_copy_addresses(context, addrs, a->req_body.addresses);
else {
ret = krb5_get_all_client_addrs (context, a->req_body.addresses);
if(ret == 0 && a->req_body.addresses->len == 0) {
free(a->req_body.addresses);
a->req_body.addresses = NULL;
}
}
if (ret)
return ret;
}
a->req_body.enc_authorization_data = NULL;
a->req_body.additional_tickets = NULL;
if(preauth != NULL) {
int i;
ALLOC(a->padata, 1);
if(a->padata == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
a->padata->val = NULL;
a->padata->len = 0;
for(i = 0; i < preauth->len; i++) {
if(preauth->val[i].type == KRB5_PADATA_ENC_TIMESTAMP){
int j;
for(j = 0; j < preauth->val[i].info.len; j++) {
krb5_salt *sp = &salt;
if(preauth->val[i].info.val[j].salttype)
salt.salttype = *preauth->val[i].info.val[j].salttype;
else
salt.salttype = KRB5_PW_SALT;
if(preauth->val[i].info.val[j].salt)
salt.saltvalue = *preauth->val[i].info.val[j].salt;
else
if(salt.salttype == KRB5_PW_SALT)
sp = NULL;
else
krb5_data_zero(&salt.saltvalue);
ret = add_padata(context, a->padata, creds->client,
key_proc, keyseed,
&preauth->val[i].info.val[j].etype, 1,
sp);
if (ret == 0)
break;
}
}
}
} else
/* not sure this is the way to use `ptypes' */
if (ptypes == NULL || *ptypes == KRB5_PADATA_NONE)
a->padata = NULL;
else if (*ptypes == KRB5_PADATA_ENC_TIMESTAMP) {
ALLOC(a->padata, 1);
if (a->padata == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
a->padata->len = 0;
a->padata->val = NULL;
/* make a v5 salted pa-data */
add_padata(context, a->padata, creds->client,
key_proc, keyseed, a->req_body.etype.val,
a->req_body.etype.len, NULL);
/* make a v4 salted pa-data */
salt.salttype = KRB5_PW_SALT;
krb5_data_zero(&salt.saltvalue);
add_padata(context, a->padata, creds->client,
key_proc, keyseed, a->req_body.etype.val,
a->req_body.etype.len, &salt);
} else {
krb5_set_error_string (context, "pre-auth type %d not supported",
*ptypes);
ret = KRB5_PREAUTH_BAD_TYPE;
goto fail;
}
return 0;
fail:
free_AS_REQ(a);
return ret;
}
static int
set_ptypes(krb5_context context,
KRB_ERROR *error,
const krb5_preauthtype **ptypes,
krb5_preauthdata **preauth)
{
static krb5_preauthdata preauth2;
static krb5_preauthtype ptypes2[] = { KRB5_PADATA_ENC_TIMESTAMP, KRB5_PADATA_NONE };
if(error->e_data) {
METHOD_DATA md;
int i;
decode_METHOD_DATA(error->e_data->data,
error->e_data->length,
&md,
NULL);
for(i = 0; i < md.len; i++){
switch(md.val[i].padata_type){
case KRB5_PADATA_ENC_TIMESTAMP:
*ptypes = ptypes2;
break;
case KRB5_PADATA_ETYPE_INFO:
*preauth = &preauth2;
ALLOC_SEQ(*preauth, 1);
(*preauth)->val[0].type = KRB5_PADATA_ENC_TIMESTAMP;
krb5_decode_ETYPE_INFO(context,
md.val[i].padata_value.data,
md.val[i].padata_value.length,
&(*preauth)->val[0].info,
NULL);
break;
default:
break;
}
}
free_METHOD_DATA(&md);
} else {
*ptypes = ptypes2;
}
return(1);
}
krb5_error_code KRB5_LIB_FUNCTION
krb5_get_in_cred(krb5_context context,
krb5_flags options,
const krb5_addresses *addrs,
const krb5_enctype *etypes,
const krb5_preauthtype *ptypes,
const krb5_preauthdata *preauth,
krb5_key_proc key_proc,
krb5_const_pointer keyseed,
krb5_decrypt_proc decrypt_proc,
krb5_const_pointer decryptarg,
krb5_creds *creds,
krb5_kdc_rep *ret_as_reply)
{
krb5_error_code ret;
AS_REQ a;
krb5_kdc_rep rep;
krb5_data req, resp;
size_t len;
krb5_salt salt;
krb5_keyblock *key;
size_t size;
krb5_kdc_flags opts;
PA_DATA *pa;
krb5_enctype etype;
krb5_preauthdata *my_preauth = NULL;
unsigned nonce;
int done;
opts.i = options;
krb5_generate_random_block (&nonce, sizeof(nonce));
nonce &= 0xffffffff;
do {
done = 1;
ret = init_as_req (context,
opts,
creds,
addrs,
etypes,
ptypes,
preauth,
key_proc,
keyseed,
nonce,
&a);
if (my_preauth) {
free_ETYPE_INFO(&my_preauth->val[0].info);
free (my_preauth->val);
my_preauth = NULL;
}
if (ret)
return ret;
ASN1_MALLOC_ENCODE(AS_REQ, req.data, req.length, &a, &len, ret);
free_AS_REQ(&a);
if (ret)
return ret;
if(len != req.length)
krb5_abortx(context, "internal error in ASN.1 encoder");
ret = krb5_sendto_kdc (context, &req, &creds->client->realm, &resp);
krb5_data_free(&req);
if (ret)
return ret;
memset (&rep, 0, sizeof(rep));
ret = decode_AS_REP(resp.data, resp.length, &rep.kdc_rep, &size);
if(ret) {
/* let's try to parse it as a KRB-ERROR */
KRB_ERROR error;
int ret2;
ret2 = krb5_rd_error(context, &resp, &error);
if(ret2 && resp.data && ((char*)resp.data)[0] == 4)
ret = KRB5KRB_AP_ERR_V4_REPLY;
krb5_data_free(&resp);
if (ret2 == 0) {
ret = krb5_error_from_rd_error(context, &error, creds);
/* if no preauth was set and KDC requires it, give it
one more try */
if (!ptypes && !preauth
&& ret == KRB5KDC_ERR_PREAUTH_REQUIRED
#if 0
|| ret == KRB5KDC_ERR_BADOPTION
#endif
&& set_ptypes(context, &error, &ptypes, &my_preauth)) {
done = 0;
preauth = my_preauth;
krb5_free_error_contents(context, &error);
krb5_clear_error_string(context);
continue;
}
if(ret_as_reply)
ret_as_reply->error = error;
else
free_KRB_ERROR (&error);
return ret;
}
return ret;
}
krb5_data_free(&resp);
} while(!done);
pa = NULL;
etype = rep.kdc_rep.enc_part.etype;
if(rep.kdc_rep.padata){
int index = 0;
pa = krb5_find_padata(rep.kdc_rep.padata->val, rep.kdc_rep.padata->len,
KRB5_PADATA_PW_SALT, &index);
if(pa == NULL) {
index = 0;
pa = krb5_find_padata(rep.kdc_rep.padata->val,
rep.kdc_rep.padata->len,
KRB5_PADATA_AFS3_SALT, &index);
}
}
if(pa) {
salt.salttype = pa->padata_type;
salt.saltvalue = pa->padata_value;
ret = (*key_proc)(context, etype, salt, keyseed, &key);
} else {
/* make a v5 salted pa-data */
ret = krb5_get_pw_salt (context, creds->client, &salt);
if (ret)
goto out;
ret = (*key_proc)(context, etype, salt, keyseed, &key);
krb5_free_salt(context, salt);
}
if (ret)
goto out;
ret = _krb5_extract_ticket(context,
&rep,
creds,
key,
keyseed,
KRB5_KU_AS_REP_ENC_PART,
NULL,
nonce,
FALSE,
opts.b.request_anonymous,
decrypt_proc,
decryptarg);
memset (key->keyvalue.data, 0, key->keyvalue.length);
krb5_free_keyblock_contents (context, key);
free (key);
out:
if (ret == 0 && ret_as_reply)
*ret_as_reply = rep;
else
krb5_free_kdc_rep (context, &rep);
return ret;
}
krb5_error_code KRB5_LIB_FUNCTION
krb5_get_in_tkt(krb5_context context,
krb5_flags options,
const krb5_addresses *addrs,
const krb5_enctype *etypes,
const krb5_preauthtype *ptypes,
krb5_key_proc key_proc,
krb5_const_pointer keyseed,
krb5_decrypt_proc decrypt_proc,
krb5_const_pointer decryptarg,
krb5_creds *creds,
krb5_ccache ccache,
krb5_kdc_rep *ret_as_reply)
{
krb5_error_code ret;
krb5_kdc_flags opts;
opts.i = 0;
opts.b = int2KDCOptions(options);
ret = krb5_get_in_cred (context,
opts.i,
addrs,
etypes,
ptypes,
NULL,
key_proc,
keyseed,
decrypt_proc,
decryptarg,
creds,
ret_as_reply);
if(ret)
return ret;
if (ccache)
ret = krb5_cc_store_cred (context, ccache, creds);
return ret;
}