/* $NetBSD: get_cred.c,v 1.3.8.1 2023/08/11 13:40:01 martin Exp $ */
/*
* Copyright (c) 1997 - 2008 Kungliga Tekniska Hﾃｶgskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Portions Copyright (c) 2009 Apple Inc. 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"
#include <assert.h>
static krb5_error_code
get_cred_kdc_capath(krb5_context, krb5_kdc_flags,
krb5_ccache, krb5_creds *, krb5_principal,
Ticket *, krb5_creds **, krb5_creds ***);
/*
* Take the `body' and encode it into `padata' using the credentials
* in `creds'.
*/
static krb5_error_code
make_pa_tgs_req(krb5_context context,
krb5_auth_context ac,
KDC_REQ_BODY *body,
PA_DATA *padata,
krb5_creds *creds)
{
u_char *buf;
size_t buf_size;
size_t len = 0;
krb5_data in_data;
krb5_error_code ret;
ASN1_MALLOC_ENCODE(KDC_REQ_BODY, buf, buf_size, body, &len, ret);
if (ret)
goto out;
if(buf_size != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
in_data.length = len;
in_data.data = buf;
ret = _krb5_mk_req_internal(context, &ac, 0, &in_data, creds,
&padata->padata_value,
KRB5_KU_TGS_REQ_AUTH_CKSUM,
KRB5_KU_TGS_REQ_AUTH);
out:
free (buf);
if(ret)
return ret;
padata->padata_type = KRB5_PADATA_TGS_REQ;
return 0;
}
/*
* Set the `enc-authorization-data' in `req_body' based on `authdata'
*/
static krb5_error_code
set_auth_data (krb5_context context,
KDC_REQ_BODY *req_body,
krb5_authdata *authdata,
krb5_keyblock *subkey)
{
if(authdata->len) {
size_t len = 0, buf_size;
unsigned char *buf;
krb5_crypto crypto;
krb5_error_code ret;
ASN1_MALLOC_ENCODE(AuthorizationData, buf, buf_size, authdata,
&len, ret);
if (ret)
return ret;
if (buf_size != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
ALLOC(req_body->enc_authorization_data, 1);
if (req_body->enc_authorization_data == NULL) {
free (buf);
return krb5_enomem(context);
}
ret = krb5_crypto_init(context, subkey, 0, &crypto);
if (ret) {
free (buf);
free (req_body->enc_authorization_data);
req_body->enc_authorization_data = NULL;
return ret;
}
krb5_encrypt_EncryptedData(context,
crypto,
KRB5_KU_TGS_REQ_AUTH_DAT_SUBKEY,
buf,
len,
0,
req_body->enc_authorization_data);
free (buf);
krb5_crypto_destroy(context, crypto);
} else {
req_body->enc_authorization_data = NULL;
}
return 0;
}
/*
* Create a tgs-req in `t' with `addresses', `flags', `second_ticket'
* (if not-NULL), `in_creds', `krbtgt', and returning the generated
* subkey in `subkey'.
*/
static krb5_error_code
init_tgs_req (krb5_context context,
krb5_ccache ccache,
krb5_addresses *addresses,
krb5_kdc_flags flags,
Ticket *second_ticket,
krb5_creds *in_creds,
krb5_creds *krbtgt,
unsigned nonce,
const METHOD_DATA *padata,
krb5_keyblock **subkey,
TGS_REQ *t)
{
krb5_auth_context ac = NULL;
krb5_error_code ret = 0;
memset(t, 0, sizeof(*t));
t->pvno = 5;
t->msg_type = krb_tgs_req;
if (in_creds->session.keytype) {
ALLOC_SEQ(&t->req_body.etype, 1);
if(t->req_body.etype.val == NULL) {
ret = krb5_enomem(context);
goto fail;
}
t->req_body.etype.val[0] = in_creds->session.keytype;
} else {
ret = _krb5_init_etype(context,
KRB5_PDU_TGS_REQUEST,
&t->req_body.etype.len,
&t->req_body.etype.val,
NULL);
}
if (ret)
goto fail;
t->req_body.addresses = addresses;
t->req_body.kdc_options = flags.b;
t->req_body.kdc_options.forwardable = krbtgt->flags.b.forwardable;
t->req_body.kdc_options.renewable = krbtgt->flags.b.renewable;
t->req_body.kdc_options.proxiable = krbtgt->flags.b.proxiable;
ret = copy_Realm(&in_creds->server->realm, &t->req_body.realm);
if (ret)
goto fail;
ALLOC(t->req_body.sname, 1);
if (t->req_body.sname == NULL) {
ret = krb5_enomem(context);
goto fail;
}
/* some versions of some code might require that the client be
present in TGS-REQs, but this is clearly against the spec */
ret = copy_PrincipalName(&in_creds->server->name, t->req_body.sname);
if (ret)
goto fail;
if (krbtgt->times.starttime) {
ALLOC(t->req_body.from, 1);
if(t->req_body.from == NULL){
ret = krb5_enomem(context);
goto fail;
}
*t->req_body.from = in_creds->times.starttime;
}
/* req_body.till should be NULL if there is no endtime specified,
but old MIT code (like DCE secd) doesn't like that */
ALLOC(t->req_body.till, 1);
if(t->req_body.till == NULL){
ret = krb5_enomem(context);
goto fail;
}
*t->req_body.till = in_creds->times.endtime;
if (t->req_body.kdc_options.renewable && krbtgt->times.renew_till) {
ALLOC(t->req_body.rtime, 1);
if(t->req_body.rtime == NULL){
ret = krb5_enomem(context);
goto fail;
}
*t->req_body.rtime = in_creds->times.renew_till;
}
t->req_body.nonce = nonce;
if(second_ticket){
ALLOC(t->req_body.additional_tickets, 1);
if (t->req_body.additional_tickets == NULL) {
ret = krb5_enomem(context);
goto fail;
}
ALLOC_SEQ(t->req_body.additional_tickets, 1);
if (t->req_body.additional_tickets->val == NULL) {
ret = krb5_enomem(context);
goto fail;
}
ret = copy_Ticket(second_ticket, t->req_body.additional_tickets->val);
if (ret)
goto fail;
}
ALLOC(t->padata, 1);
if (t->padata == NULL) {
ret = krb5_enomem(context);
goto fail;
}
ALLOC_SEQ(t->padata, 1 + padata->len);
if (t->padata->val == NULL) {
ret = krb5_enomem(context);
goto fail;
}
{
size_t i;
for (i = 0; i < padata->len; i++) {
ret = copy_PA_DATA(&padata->val[i], &t->padata->val[i + 1]);
if (ret) {
krb5_set_error_message(context, ret,
N_("malloc: out of memory", ""));
goto fail;
}
}
}
ret = krb5_auth_con_init(context, &ac);
if(ret)
goto fail;
ret = krb5_auth_con_generatelocalsubkey(context, ac, &krbtgt->session);
if (ret)
goto fail;
ret = set_auth_data (context, &t->req_body, &in_creds->authdata,
ac->local_subkey);
if (ret)
goto fail;
ret = make_pa_tgs_req(context,
ac,
&t->req_body,
&t->padata->val[0],
krbtgt);
if(ret)
goto fail;
ret = krb5_auth_con_getlocalsubkey(context, ac, subkey);
if (ret)
goto fail;
fail:
if (ac)
krb5_auth_con_free(context, ac);
if (ret) {
t->req_body.addresses = NULL;
free_TGS_REQ (t);
}
return ret;
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_get_krbtgt(krb5_context context,
krb5_ccache id,
krb5_realm realm,
krb5_creds **cred)
{
krb5_error_code ret;
krb5_creds tmp_cred;
memset(&tmp_cred, 0, sizeof(tmp_cred));
ret = krb5_cc_get_principal(context, id, &tmp_cred.client);
if (ret)
return ret;
ret = krb5_make_principal(context,
&tmp_cred.server,
realm,
KRB5_TGS_NAME,
realm,
NULL);
if(ret) {
krb5_free_principal(context, tmp_cred.client);
return ret;
}
/*
* The forwardable TGT might not be the start TGT, in which case, it is
* generally, but not always already cached. Just in case, get it again if
* lost.
*/
ret = krb5_get_credentials(context,
0,
id,
&tmp_cred,
cred);
krb5_free_principal(context, tmp_cred.client);
krb5_free_principal(context, tmp_cred.server);
if(ret)
return ret;
return 0;
}
/* DCE compatible decrypt proc */
static krb5_error_code KRB5_CALLCONV
decrypt_tkt_with_subkey (krb5_context context,
krb5_keyblock *key,
krb5_key_usage usage,
krb5_const_pointer skey,
krb5_kdc_rep *dec_rep)
{
const krb5_keyblock *subkey = skey;
krb5_error_code ret = 0;
krb5_data data;
size_t size;
krb5_crypto crypto;
assert(usage == 0);
krb5_data_zero(&data);
/*
* start out with trying with subkey if we have one
*/
if (subkey) {
ret = krb5_crypto_init(context, subkey, 0, &crypto);
if (ret)
return ret;
ret = krb5_decrypt_EncryptedData (context,
crypto,
KRB5_KU_TGS_REP_ENC_PART_SUB_KEY,
&dec_rep->kdc_rep.enc_part,
&data);
/*
* If the is Windows 2000 DC, we need to retry with key usage
* 8 when doing ARCFOUR.
*/
if (ret && subkey->keytype == ETYPE_ARCFOUR_HMAC_MD5) {
ret = krb5_decrypt_EncryptedData(context,
crypto,
8,
&dec_rep->kdc_rep.enc_part,
&data);
}
krb5_crypto_destroy(context, crypto);
}
if (subkey == NULL || ret) {
ret = krb5_crypto_init(context, key, 0, &crypto);
if (ret)
return ret;
ret = krb5_decrypt_EncryptedData (context,
crypto,
KRB5_KU_TGS_REP_ENC_PART_SESSION,
&dec_rep->kdc_rep.enc_part,
&data);
krb5_crypto_destroy(context, crypto);
}
if (ret)
return ret;
ret = decode_EncASRepPart(data.data,
data.length,
&dec_rep->enc_part,
&size);
if (ret)
ret = decode_EncTGSRepPart(data.data,
data.length,
&dec_rep->enc_part,
&size);
if (ret)
krb5_set_error_message(context, ret,
N_("Failed to decode encpart in ticket", ""));
krb5_data_free (&data);
return ret;
}
static krb5_error_code
get_cred_kdc(krb5_context context,
krb5_ccache id,
krb5_kdc_flags flags,
krb5_addresses *addresses,
krb5_creds *in_creds,
krb5_creds *krbtgt,
krb5_principal impersonate_principal,
Ticket *second_ticket,
krb5_creds *out_creds)
{
TGS_REQ req;
krb5_data enc;
krb5_data resp;
krb5_kdc_rep rep = {0};
KRB_ERROR error;
krb5_error_code ret;
unsigned nonce;
krb5_keyblock *subkey = NULL;
size_t len = 0;
Ticket second_ticket_data;
METHOD_DATA padata;
krb5_data_zero(&resp);
krb5_data_zero(&enc);
padata.val = NULL;
padata.len = 0;
krb5_generate_random_block(&nonce, sizeof(nonce));
nonce &= 0xffffffff;
if(flags.b.enc_tkt_in_skey && second_ticket == NULL){
ret = decode_Ticket(in_creds->second_ticket.data,
in_creds->second_ticket.length,
&second_ticket_data, &len);
if(ret)
return ret;
second_ticket = &second_ticket_data;
}
if (impersonate_principal) {
krb5_crypto crypto;
PA_S4U2Self self;
krb5_data data;
void *buf;
size_t size = 0;
self.name = impersonate_principal->name;
self.realm = impersonate_principal->realm;
self.auth = estrdup("Kerberos");
ret = _krb5_s4u2self_to_checksumdata(context, &self, &data);
if (ret) {
free(self.auth);
goto out;
}
ret = krb5_crypto_init(context, &krbtgt->session, 0, &crypto);
if (ret) {
free(self.auth);
krb5_data_free(&data);
goto out;
}
ret = krb5_create_checksum(context,
crypto,
KRB5_KU_OTHER_CKSUM,
0,
data.data,
data.length,
&self.cksum);
krb5_crypto_destroy(context, crypto);
krb5_data_free(&data);
if (ret) {
free(self.auth);
goto out;
}
ASN1_MALLOC_ENCODE(PA_S4U2Self, buf, len, &self, &size, ret);
free(self.auth);
free_Checksum(&self.cksum);
if (ret)
goto out;
if (len != size)
krb5_abortx(context, "internal asn1 error");
ret = krb5_padata_add(context, &padata, KRB5_PADATA_FOR_USER, buf, len);
if (ret)
goto out;
}
ret = init_tgs_req (context,
id,
addresses,
flags,
second_ticket,
in_creds,
krbtgt,
nonce,
&padata,
&subkey,
&req);
if (ret)
goto out;
ASN1_MALLOC_ENCODE(TGS_REQ, enc.data, enc.length, &req, &len, ret);
if (ret)
goto out;
if(enc.length != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
/* don't free addresses */
req.req_body.addresses = NULL;
free_TGS_REQ(&req);
/*
* Send and receive
*/
{
krb5_sendto_ctx stctx;
ret = krb5_sendto_ctx_alloc(context, &stctx);
if (ret)
return ret;
krb5_sendto_ctx_set_func(stctx, _krb5_kdc_retry, NULL);
ret = krb5_sendto_context (context, stctx, &enc,
krbtgt->server->name.name_string.val[1],
&resp);
krb5_sendto_ctx_free(context, stctx);
}
if(ret)
goto out;
if(decode_TGS_REP(resp.data, resp.length, &rep.kdc_rep, &len) == 0) {
unsigned eflags = 0;
ret = krb5_copy_principal(context,
in_creds->client,
&out_creds->client);
if(ret)
goto out2;
ret = krb5_copy_principal(context,
in_creds->server,
&out_creds->server);
if(ret)
goto out2;
/* this should go someplace else */
out_creds->times.endtime = in_creds->times.endtime;
/* XXX should do better testing */
if (flags.b.cname_in_addl_tkt || impersonate_principal)
eflags |= EXTRACT_TICKET_ALLOW_CNAME_MISMATCH;
if (flags.b.request_anonymous)
eflags |= EXTRACT_TICKET_MATCH_ANON;
ret = _krb5_extract_ticket(context,
&rep,
out_creds,
&krbtgt->session,
NULL,
0,
&krbtgt->addresses,
nonce,
eflags,
NULL,
decrypt_tkt_with_subkey,
subkey);
out2:
krb5_free_kdc_rep(context, &rep);
} else if(krb5_rd_error(context, &resp, &error) == 0) {
ret = krb5_error_from_rd_error(context, &error, in_creds);
krb5_free_error_contents(context, &error);
} else if(resp.length > 0 && ((char*)resp.data)[0] == 4) {
ret = KRB5KRB_AP_ERR_V4_REPLY;
krb5_clear_error_message(context);
} else {
ret = KRB5KRB_AP_ERR_MSG_TYPE;
krb5_clear_error_message(context);
}
out:
if (second_ticket == &second_ticket_data)
free_Ticket(&second_ticket_data);
free_METHOD_DATA(&padata);
krb5_data_free(&resp);
krb5_data_free(&enc);
if(subkey)
krb5_free_keyblock(context, subkey);
return ret;
}
/*
* same as above, just get local addresses first if the krbtgt have
* them and the realm is not addressless
*/
static krb5_error_code
get_cred_kdc_address(krb5_context context,
krb5_ccache id,
krb5_kdc_flags flags,
krb5_addresses *addrs,
krb5_creds *in_creds,
krb5_creds *krbtgt,
krb5_principal impersonate_principal,
Ticket *second_ticket,
krb5_creds *out_creds)
{
krb5_error_code ret;
krb5_addresses addresses = { 0, NULL };
/*
* Inherit the address-ness of the krbtgt if the address is not
* specified.
*/
if (addrs == NULL && krbtgt->addresses.len != 0) {
krb5_boolean noaddr;
krb5_appdefault_boolean(context, NULL, krbtgt->server->realm,
"no-addresses", FALSE, &noaddr);
if (!noaddr) {
krb5_get_all_client_addrs(context, &addresses);
/* XXX this sucks. */
addrs = &addresses;
if(addresses.len == 0)
addrs = NULL;
}
}
ret = get_cred_kdc(context, id, flags, addrs, in_creds,
krbtgt, impersonate_principal,
second_ticket, out_creds);
krb5_free_addresses(context, &addresses);
return ret;
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_kdc_cred(krb5_context context,
krb5_ccache id,
krb5_kdc_flags flags,
krb5_addresses *addresses,
Ticket *second_ticket,
krb5_creds *in_creds,
krb5_creds **out_creds
)
{
krb5_error_code ret;
krb5_creds *krbtgt;
*out_creds = calloc(1, sizeof(**out_creds));
if(*out_creds == NULL)
return krb5_enomem(context);
ret = _krb5_get_krbtgt (context,
id,
in_creds->server->realm,
&krbtgt);
if(ret) {
free(*out_creds);
*out_creds = NULL;
return ret;
}
ret = get_cred_kdc(context, id, flags, addresses,
in_creds, krbtgt, NULL, NULL, *out_creds);
krb5_free_creds (context, krbtgt);
if(ret) {
free(*out_creds);
*out_creds = NULL;
}
return ret;
}
static int
not_found(krb5_context context, krb5_const_principal p, krb5_error_code code)
{
krb5_error_code ret;
const char *err;
char *str;
err = krb5_get_error_message(context, code);
ret = krb5_unparse_name(context, p, &str);
if(ret) {
krb5_clear_error_message(context);
return code;
}
krb5_set_error_message(context, code, N_("%s (%s)", ""), err, str);
free(str);
return code;
}
static krb5_error_code
find_cred(krb5_context context,
krb5_ccache id,
krb5_principal server,
krb5_creds **tgts,
krb5_creds *out_creds)
{
krb5_error_code ret;
krb5_creds mcreds;
krb5_cc_clear_mcred(&mcreds);
mcreds.server = server;
krb5_timeofday(context, &mcreds.times.endtime);
ret = krb5_cc_retrieve_cred(context, id,
KRB5_TC_DONT_MATCH_REALM |
KRB5_TC_MATCH_TIMES,
&mcreds, out_creds);
if(ret == 0)
return 0;
while(tgts && *tgts){
if(krb5_compare_creds(context, KRB5_TC_DONT_MATCH_REALM,
&mcreds, *tgts)){
ret = krb5_copy_creds_contents(context, *tgts, out_creds);
return ret;
}
tgts++;
}
return not_found(context, server, KRB5_CC_NOTFOUND);
}
static krb5_error_code
add_cred(krb5_context context, krb5_creds const *tkt, krb5_creds ***tgts)
{
int i;
krb5_error_code ret;
krb5_creds **tmp = *tgts;
for(i = 0; tmp && tmp[i]; i++); /* XXX */
tmp = realloc(tmp, (i+2)*sizeof(*tmp));
if(tmp == NULL)
return krb5_enomem(context);
*tgts = tmp;
ret = krb5_copy_creds(context, tkt, &tmp[i]);
tmp[i+1] = NULL;
return ret;
}
static krb5_error_code
get_cred_kdc_capath_worker(krb5_context context,
krb5_kdc_flags flags,
krb5_ccache ccache,
krb5_creds *in_creds,
krb5_const_realm try_realm,
krb5_principal impersonate_principal,
Ticket *second_ticket,
krb5_creds **out_creds,
krb5_creds ***ret_tgts)
{
krb5_error_code ret;
krb5_creds *tgt = NULL;
krb5_creds tmp_creds;
krb5_const_realm client_realm, server_realm;
int ok_as_delegate = 1;
*out_creds = calloc(1, sizeof(**out_creds));
if (*out_creds == NULL)
return krb5_enomem(context);
memset(&tmp_creds, 0, sizeof(tmp_creds));
client_realm = krb5_principal_get_realm(context, in_creds->client);
server_realm = krb5_principal_get_realm(context, in_creds->server);
ret = krb5_copy_principal(context, in_creds->client, &tmp_creds.client);
if (ret)
goto out;
ret = krb5_make_principal(context,
&tmp_creds.server,
try_realm,
KRB5_TGS_NAME,
server_realm,
NULL);
if (ret)
goto out;
{
krb5_creds tgts;
/*
* If we have krbtgt/server_realm@try_realm cached, use it and we're
* done.
*/
ret = find_cred(context, ccache, tmp_creds.server,
*ret_tgts, &tgts);
if (ret == 0) {
/* only allow implicit ok_as_delegate if the realm is the clients realm */
if (strcmp(try_realm, client_realm) != 0
|| strcmp(try_realm, server_realm) != 0) {
ok_as_delegate = tgts.flags.b.ok_as_delegate;
}
ret = get_cred_kdc_address(context, ccache, flags, NULL,
in_creds, &tgts,
impersonate_principal,
second_ticket,
*out_creds);
krb5_free_cred_contents(context, &tgts);
if (ret == 0 &&
!krb5_principal_compare(context, in_creds->server,
(*out_creds)->server)) {
ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
}
if (ret == 0 && ok_as_delegate == 0)
(*out_creds)->flags.b.ok_as_delegate = 0;
goto out;
}
}
if (krb5_realm_compare(context, in_creds->client, in_creds->server)) {
ret = not_found(context, in_creds->server, KRB5_CC_NOTFOUND);
goto out;
}
/*
* XXX This can loop forever, plus we recurse, so we can't just keep a
* count here. The count would have to get passed around by reference.
*
* The KDCs check for transit loops for us, and capath data is finite, so
* in fact we'll fall out of this loop at some point. We should do our own
* transit loop checking (like get_cred_kdc_referral()), and we should
* impose a max number of iterations altogether. But barring malicious or
* broken KDCs, this is good enough.
*/
while (1) {
heim_general_string tgt_inst;
ret = get_cred_kdc_capath(context, flags, ccache, &tmp_creds,
NULL, NULL, &tgt, ret_tgts);
if (ret)
goto out;
/*
* if either of the chain or the ok_as_delegate was stripped
* by the kdc, make sure we strip it too.
*/
if (ok_as_delegate == 0 || tgt->flags.b.ok_as_delegate == 0) {
ok_as_delegate = 0;
tgt->flags.b.ok_as_delegate = 0;
}
ret = add_cred(context, tgt, ret_tgts);
if (ret)
goto out;
tgt_inst = tgt->server->name.name_string.val[1];
if (strcmp(tgt_inst, server_realm) == 0)
break;
krb5_free_principal(context, tmp_creds.server);
tmp_creds.server = NULL;
ret = krb5_make_principal(context, &tmp_creds.server,
tgt_inst, KRB5_TGS_NAME, server_realm, NULL);
if (ret)
goto out;
ret = krb5_free_creds(context, tgt);
tgt = NULL;
if (ret)
goto out;
}
ret = get_cred_kdc_address(context, ccache, flags, NULL,
in_creds, tgt, impersonate_principal,
second_ticket, *out_creds);
if (ret == 0 &&
!krb5_principal_compare(context, in_creds->server,
(*out_creds)->server)) {
krb5_free_cred_contents(context, *out_creds);
ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
}
if (ret == 0 && ok_as_delegate == 0)
(*out_creds)->flags.b.ok_as_delegate = 0;
out:
if (ret) {
krb5_free_creds(context, *out_creds);
*out_creds = NULL;
}
if (tmp_creds.server)
krb5_free_principal(context, tmp_creds.server);
if (tmp_creds.client)
krb5_free_principal(context, tmp_creds.client);
if (tgt)
krb5_free_creds(context, tgt);
return ret;
}
/*
get_cred(server)
creds = cc_get_cred(server)
if(creds) return creds
tgt = cc_get_cred(krbtgt/server_realm@any_realm)
if(tgt)
return get_cred_tgt(server, tgt)
if(client_realm == server_realm)
return NULL
tgt = get_cred(krbtgt/server_realm@client_realm)
while(tgt_inst != server_realm)
tgt = get_cred(krbtgt/server_realm@tgt_inst)
return get_cred_tgt(server, tgt)
*/
static krb5_error_code
get_cred_kdc_capath(krb5_context context,
krb5_kdc_flags flags,
krb5_ccache ccache,
krb5_creds *in_creds,
krb5_principal impersonate_principal,
Ticket *second_ticket,
krb5_creds **out_creds,
krb5_creds ***ret_tgts)
{
krb5_error_code ret;
krb5_const_realm client_realm, server_realm, try_realm;
client_realm = krb5_principal_get_realm(context, in_creds->client);
server_realm = krb5_principal_get_realm(context, in_creds->server);
try_realm = client_realm;
ret = get_cred_kdc_capath_worker(context, flags, ccache, in_creds, try_realm,
impersonate_principal, second_ticket, out_creds,
ret_tgts);
if (ret == KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN) {
try_realm = krb5_config_get_string(context, NULL, "capaths",
client_realm, server_realm, NULL);
if (try_realm != NULL && strcmp(try_realm, client_realm)) {
ret = get_cred_kdc_capath_worker(context, flags, ccache, in_creds,
try_realm, impersonate_principal,
second_ticket, out_creds, ret_tgts);
}
}
return ret;
}
/*
* Get a service ticket from a KDC by chasing referrals from a start realm.
*
* All referral TGTs produced in the process are thrown away when we're done.
* We don't store them, and we don't allow other search mechanisms (capaths) to
* use referral TGTs produced here.
*/
static krb5_error_code
get_cred_kdc_referral(krb5_context context,
krb5_kdc_flags flags,
krb5_ccache ccache,
krb5_creds *in_creds,
krb5_principal impersonate_principal,
Ticket *second_ticket,
krb5_creds **out_creds)
{
krb5_realm start_realm = NULL;
krb5_data config_start_realm;
krb5_error_code ret;
krb5_creds tgt, referral, ticket;
krb5_creds **referral_tgts = NULL; /* used for loop detection */
int loop = 0;
int ok_as_delegate = 1;
size_t i;
if (in_creds->server->name.name_string.len < 2 && !flags.b.canonicalize) {
krb5_set_error_message(context, KRB5KDC_ERR_PATH_NOT_ACCEPTED,
N_("Name too short to do referals, skipping", ""));
return KRB5KDC_ERR_PATH_NOT_ACCEPTED;
}
memset(&tgt, 0, sizeof(tgt));
memset(&ticket, 0, sizeof(ticket));
flags.b.canonicalize = 1;
*out_creds = NULL;
ret = krb5_cc_get_config(context, ccache, NULL, "start_realm", &config_start_realm);
if (ret == 0) {
start_realm = strndup(config_start_realm.data, config_start_realm.length);
krb5_data_free(&config_start_realm);
} else {
start_realm = strdup(krb5_principal_get_realm(context, in_creds->client));
}
if (start_realm == NULL)
return krb5_enomem(context);
/* find tgt for the clients base realm */
{
krb5_principal tgtname;
ret = krb5_make_principal(context, &tgtname,
start_realm,
KRB5_TGS_NAME,
start_realm,
NULL);
if (ret) {
free(start_realm);
return ret;
}
ret = find_cred(context, ccache, tgtname, NULL, &tgt);
krb5_free_principal(context, tgtname);
if (ret) {
free(start_realm);
return ret;
}
}
referral = *in_creds;
ret = krb5_copy_principal(context, in_creds->server, &referral.server);
if (ret) {
krb5_free_cred_contents(context, &tgt);
free(start_realm);
return ret;
}
ret = krb5_principal_set_realm(context, referral.server, start_realm);
free(start_realm);
start_realm = NULL;
if (ret) {
krb5_free_cred_contents(context, &tgt);
krb5_free_principal(context, referral.server);
return ret;
}
while (loop++ < 17) {
krb5_creds **tickets;
krb5_creds mcreds;
char *referral_realm;
/* Use cache if we are not doing impersonation or contrained deleg */
if (impersonate_principal == NULL || flags.b.cname_in_addl_tkt) {
krb5_cc_clear_mcred(&mcreds);
mcreds.server = referral.server;
krb5_timeofday(context, &mcreds.times.endtime);
ret = krb5_cc_retrieve_cred(context, ccache, KRB5_TC_MATCH_TIMES,
&mcreds, &ticket);
} else
ret = EINVAL;
if (ret) {
ret = get_cred_kdc_address(context, ccache, flags, NULL,
&referral, &tgt, impersonate_principal,
second_ticket, &ticket);
if (ret)
goto out;
}
/* Did we get the right ticket ? */
if (krb5_principal_compare_any_realm(context,
referral.server,
ticket.server))
break;
if (!krb5_principal_is_krbtgt(context, ticket.server)) {
krb5_set_error_message(context, KRB5KRB_AP_ERR_NOT_US,
N_("Got back an non krbtgt "
"ticket referrals", ""));
ret = KRB5KRB_AP_ERR_NOT_US;
goto out;
}
referral_realm = ticket.server->name.name_string.val[1];
/* check that there are no referrals loops */
tickets = referral_tgts;
krb5_cc_clear_mcred(&mcreds);
mcreds.server = ticket.server;
while (tickets && *tickets){
if (krb5_compare_creds(context,
KRB5_TC_DONT_MATCH_REALM,
&mcreds,
*tickets)) {
krb5_set_error_message(context, KRB5_GET_IN_TKT_LOOP,
N_("Referral from %s "
"loops back to realm %s", ""),
tgt.server->realm,
referral_realm);
ret = KRB5_GET_IN_TKT_LOOP;
goto out;
}
tickets++;
}
/*
* if either of the chain or the ok_as_delegate was stripped
* by the kdc, make sure we strip it too.
*/
if (ok_as_delegate == 0 || ticket.flags.b.ok_as_delegate == 0) {
ok_as_delegate = 0;
ticket.flags.b.ok_as_delegate = 0;
}
_krb5_debug(context, 6, "get_cred_kdc_referral: got referral "
"to %s from %s", referral_realm, referral.server->realm);
ret = add_cred(context, &ticket, &referral_tgts);
if (ret)
goto out;
/* try realm in the referral */
ret = krb5_principal_set_realm(context,
referral.server,
referral_realm);
krb5_free_cred_contents(context, &tgt);
tgt = ticket;
memset(&ticket, 0, sizeof(ticket));
if (ret)
goto out;
}
ret = krb5_copy_creds(context, &ticket, out_creds);
out:
for (i = 0; referral_tgts && referral_tgts[i]; i++)
krb5_free_creds(context, referral_tgts[i]);
free(referral_tgts);
krb5_free_principal(context, referral.server);
krb5_free_cred_contents(context, &tgt);
krb5_free_cred_contents(context, &ticket);
return ret;
}
/*
* Glue function between referrals version and old client chasing
* codebase.
*/
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_get_cred_kdc_any(krb5_context context,
krb5_kdc_flags flags,
krb5_ccache ccache,
krb5_creds *in_creds,
krb5_principal impersonate_principal,
Ticket *second_ticket,
krb5_creds **out_creds,
krb5_creds ***ret_tgts)
{
krb5_error_code ret;
krb5_deltat offset;
ret = krb5_cc_get_kdc_offset(context, ccache, &offset);
if (ret == 0) {
context->kdc_sec_offset = offset;
context->kdc_usec_offset = 0;
}
if (strcmp(in_creds->server->realm, "") != 0) {
/*
* Non-empty realm? Try capaths first. We might have local
* policy (capaths) to honor.
*/
ret = get_cred_kdc_capath(context,
flags,
ccache,
in_creds,
impersonate_principal,
second_ticket,
out_creds,
ret_tgts);
if (ret == 0)
return ret;
}
/* Otherwise try referrals */
return get_cred_kdc_referral(context,
flags,
ccache,
in_creds,
impersonate_principal,
second_ticket,
out_creds);
}
static krb5_error_code
check_cc(krb5_context context, krb5_flags options, krb5_ccache ccache,
krb5_creds *in_creds, krb5_creds *out_creds)
{
krb5_error_code ret;
krb5_timestamp now;
krb5_creds mcreds = *in_creds;
krb5_timeofday(context, &now);
if (!(options & KRB5_GC_EXPIRED_OK) &&
mcreds.times.endtime < now) {
mcreds.times.renew_till = 0;
krb5_timeofday(context, &mcreds.times.endtime);
options |= KRB5_TC_MATCH_TIMES;
}
if (mcreds.server->name.name_type == KRB5_NT_SRV_HST_NEEDS_CANON) {
/* Avoid name canonicalization in krb5_cc_retrieve_cred() */
krb5_principal_set_type(context, mcreds.server, KRB5_NT_SRV_HST);
}
if (options & KRB5_GC_ANONYMOUS) {
ret = krb5_make_principal(context,
&mcreds.client,
krb5_principal_get_realm(context, mcreds.client),
KRB5_WELLKNOWN_NAME,
KRB5_ANON_NAME,
NULL);
if (ret)
return ret;
}
ret = krb5_cc_retrieve_cred(context, ccache,
(options &
(KRB5_TC_DONT_MATCH_REALM |
KRB5_TC_MATCH_KEYTYPE |
KRB5_TC_MATCH_TIMES)),
&mcreds, out_creds);
if (options & KRB5_GC_ANONYMOUS)
krb5_free_principal(context, mcreds.client);
return ret;
}
static void
store_cred(krb5_context context, krb5_ccache ccache,
krb5_const_principal server_princ, krb5_creds *creds)
{
if (!krb5_principal_compare(context, creds->server, server_princ)) {
krb5_principal tmp_princ = creds->server;
/*
* Store the cred with the pre-canon server princ first so it
* can be found quickly in the future.
*/
creds->server = (krb5_principal)server_princ;
krb5_cc_store_cred(context, ccache, creds);
creds->server = tmp_princ;
/* Then store again with the canonicalized server princ */
}
krb5_cc_store_cred(context, ccache, creds);
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_credentials_with_flags(krb5_context context,
krb5_flags options,
krb5_kdc_flags flags,
krb5_ccache ccache,
krb5_creds *in_creds,
krb5_creds **out_creds)
{
krb5_error_code ret;
krb5_name_canon_iterator name_canon_iter = NULL;
krb5_name_canon_rule_options rule_opts;
krb5_const_principal try_princ = NULL;
krb5_principal save_princ = in_creds->server;
krb5_creds **tgts;
krb5_creds *res_creds;
int i;
if (_krb5_have_debug(context, 5)) {
char *unparsed;
ret = krb5_unparse_name(context, in_creds->server, &unparsed);
if (ret) {
_krb5_debug(context, 5, "krb5_get_creds: unable to display "
"requested service principal");
} else {
_krb5_debug(context, 5, "krb5_get_creds: requesting a ticket "
"for %s", unparsed);
free(unparsed);
}
}
if (in_creds->session.keytype) {
ret = krb5_enctype_valid(context, in_creds->session.keytype);
if (ret)
return ret;
options |= KRB5_TC_MATCH_KEYTYPE;
}
*out_creds = NULL;
res_creds = calloc(1, sizeof(*res_creds));
if (res_creds == NULL)
return krb5_enomem(context);
ret = krb5_name_canon_iterator_start(context, in_creds->server,
&name_canon_iter);
if (ret)
return ret;
next_rule:
krb5_free_cred_contents(context, res_creds);
memset(res_creds, 0, sizeof (*res_creds));
ret = krb5_name_canon_iterate(context, &name_canon_iter, &try_princ,
&rule_opts);
in_creds->server = rk_UNCONST(try_princ);
if (ret)
goto out;
if (name_canon_iter == NULL) {
if (options & KRB5_GC_CACHED)
ret = KRB5_CC_NOTFOUND;
else
ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
goto out;
}
ret = check_cc(context, options, ccache, in_creds, res_creds);
if (ret == 0) {
*out_creds = res_creds;
res_creds = NULL;
goto out;
} else if(ret != KRB5_CC_END) {
goto out;
}
if (options & KRB5_GC_CACHED)
goto next_rule;
if(options & KRB5_GC_USER_USER)
flags.b.enc_tkt_in_skey = 1;
if (flags.b.enc_tkt_in_skey)
options |= KRB5_GC_NO_STORE;
tgts = NULL;
ret = _krb5_get_cred_kdc_any(context, flags, ccache,
in_creds, NULL, NULL, out_creds, &tgts);
for (i = 0; tgts && tgts[i]; i++) {
if ((options & KRB5_GC_NO_STORE) == 0)
krb5_cc_store_cred(context, ccache, tgts[i]);
krb5_free_creds(context, tgts[i]);
}
free(tgts);
/* We don't yet have TGS w/ FAST, so we can't protect KBR-ERRORs */
if (ret == KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN &&
!(rule_opts & KRB5_NCRO_USE_FAST))
goto next_rule;
if(ret == 0 && (options & KRB5_GC_NO_STORE) == 0)
store_cred(context, ccache, in_creds->server, *out_creds);
if (ret == 0 && _krb5_have_debug(context, 5)) {
char *unparsed;
ret = krb5_unparse_name(context, (*out_creds)->server, &unparsed);
if (ret) {
_krb5_debug(context, 5, "krb5_get_creds: unable to display "
"service principal");
} else {
_krb5_debug(context, 5, "krb5_get_creds: got a ticket for %s",
unparsed);
free(unparsed);
}
}
out:
in_creds->server = save_princ;
krb5_free_creds(context, res_creds);
krb5_free_name_canon_iterator(context, name_canon_iter);
if (ret)
return not_found(context, in_creds->server, ret);
return 0;
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_credentials(krb5_context context,
krb5_flags options,
krb5_ccache ccache,
krb5_creds *in_creds,
krb5_creds **out_creds)
{
krb5_kdc_flags flags;
flags.i = 0;
return krb5_get_credentials_with_flags(context, options, flags,
ccache, in_creds, out_creds);
}
struct krb5_get_creds_opt_data {
krb5_principal self;
krb5_flags options;
krb5_enctype enctype;
Ticket *ticket;
};
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_creds_opt_alloc(krb5_context context, krb5_get_creds_opt *opt)
{
*opt = calloc(1, sizeof(**opt));
if (*opt == NULL)
return krb5_enomem(context);
return 0;
}
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_get_creds_opt_free(krb5_context context, krb5_get_creds_opt opt)
{
if (opt->self)
krb5_free_principal(context, opt->self);
if (opt->ticket) {
free_Ticket(opt->ticket);
free(opt->ticket);
}
memset(opt, 0, sizeof(*opt));
free(opt);
}
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_get_creds_opt_set_options(krb5_context context,
krb5_get_creds_opt opt,
krb5_flags options)
{
opt->options = options;
}
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_get_creds_opt_add_options(krb5_context context,
krb5_get_creds_opt opt,
krb5_flags options)
{
opt->options |= options;
}
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_get_creds_opt_set_enctype(krb5_context context,
krb5_get_creds_opt opt,
krb5_enctype enctype)
{
opt->enctype = enctype;
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_creds_opt_set_impersonate(krb5_context context,
krb5_get_creds_opt opt,
krb5_const_principal self)
{
if (opt->self)
krb5_free_principal(context, opt->self);
return krb5_copy_principal(context, self, &opt->self);
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_creds_opt_set_ticket(krb5_context context,
krb5_get_creds_opt opt,
const Ticket *ticket)
{
if (opt->ticket) {
free_Ticket(opt->ticket);
free(opt->ticket);
opt->ticket = NULL;
}
if (ticket) {
krb5_error_code ret;
opt->ticket = malloc(sizeof(*ticket));
if (opt->ticket == NULL)
return krb5_enomem(context);
ret = copy_Ticket(ticket, opt->ticket);
if (ret) {
free(opt->ticket);
opt->ticket = NULL;
krb5_set_error_message(context, ret,
N_("malloc: out of memory", ""));
return ret;
}
}
return 0;
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_creds(krb5_context context,
krb5_get_creds_opt opt,
krb5_ccache ccache,
krb5_const_principal inprinc,
krb5_creds **out_creds)
{
krb5_kdc_flags flags;
krb5_flags options;
krb5_creds in_creds;
krb5_error_code ret;
krb5_creds **tgts;
krb5_creds *res_creds;
krb5_const_principal try_princ = NULL;
krb5_name_canon_iterator name_canon_iter = NULL;
krb5_name_canon_rule_options rule_opts;
int i;
int type;
const char *comp;
memset(&in_creds, 0, sizeof(in_creds));
in_creds.server = rk_UNCONST(inprinc);
if (_krb5_have_debug(context, 5)) {
char *unparsed;
ret = krb5_unparse_name(context, in_creds.server, &unparsed);
if (ret) {
_krb5_debug(context, 5, "krb5_get_creds: unable to display "
"requested service principal");
} else {
_krb5_debug(context, 5, "krb5_get_creds: requesting a ticket "
"for %s", unparsed);
free(unparsed);
}
}
if (opt && opt->enctype) {
ret = krb5_enctype_valid(context, opt->enctype);
if (ret)
return ret;
}
ret = krb5_cc_get_principal(context, ccache, &in_creds.client);
if (ret)
return ret;
if (opt)
options = opt->options;
else
options = 0;
flags.i = 0;
*out_creds = NULL;
res_creds = calloc(1, sizeof(*res_creds));
if (res_creds == NULL) {
krb5_free_principal(context, in_creds.client);
return krb5_enomem(context);
}
if (opt && opt->enctype) {
in_creds.session.keytype = opt->enctype;
options |= KRB5_TC_MATCH_KEYTYPE;
}
ret = krb5_name_canon_iterator_start(context, in_creds.server,
&name_canon_iter);
if (ret)
goto out;
next_rule:
ret = krb5_name_canon_iterate(context, &name_canon_iter, &try_princ,
&rule_opts);
in_creds.server = rk_UNCONST(try_princ);
if (ret)
goto out;
if (name_canon_iter == NULL) {
if (options & KRB5_GC_CACHED)
ret = KRB5_CC_NOTFOUND;
else
ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
goto out;
}
ret = check_cc(context, options, ccache, &in_creds, res_creds);
if (ret == 0) {
*out_creds = res_creds;
res_creds = NULL;
goto out;
} else if (ret != KRB5_CC_END) {
goto out;
}
if (options & KRB5_GC_CACHED)
goto next_rule;
type = krb5_principal_get_type(context, try_princ);
comp = krb5_principal_get_comp_string(context, try_princ, 0);
if ((type == KRB5_NT_SRV_HST || type == KRB5_NT_UNKNOWN) &&
comp != NULL && strcmp(comp, "host") == 0)
flags.b.canonicalize = 1;
if (rule_opts & KRB5_NCRO_NO_REFERRALS)
flags.b.canonicalize = 0;
else
flags.b.canonicalize = (options & KRB5_GC_CANONICALIZE) ? 1 : 0;
if (options & KRB5_GC_USER_USER) {
flags.b.enc_tkt_in_skey = 1;
options |= KRB5_GC_NO_STORE;
}
if (options & KRB5_GC_FORWARDABLE)
flags.b.forwardable = 1;
if (options & KRB5_GC_NO_TRANSIT_CHECK)
flags.b.disable_transited_check = 1;
if (options & KRB5_GC_CONSTRAINED_DELEGATION)
flags.b.cname_in_addl_tkt = 1;
if (options & KRB5_GC_ANONYMOUS)
flags.b.request_anonymous = 1;
tgts = NULL;
ret = _krb5_get_cred_kdc_any(context, flags, ccache,
&in_creds, opt ? opt->self : 0,
opt ? opt->ticket : 0, out_creds,
&tgts);
for (i = 0; tgts && tgts[i]; i++) {
if ((options & KRB5_GC_NO_STORE) == 0)
krb5_cc_store_cred(context, ccache, tgts[i]);
krb5_free_creds(context, tgts[i]);
}
free(tgts);
/* We don't yet have TGS w/ FAST, so we can't protect KBR-ERRORs */
if (ret == KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN &&
!(rule_opts & KRB5_NCRO_USE_FAST))
goto next_rule;
if (ret == 0 && (options & KRB5_GC_NO_STORE) == 0)
store_cred(context, ccache, inprinc, *out_creds);
if (ret == 0 && _krb5_have_debug(context, 5)) {
char *unparsed;
ret = krb5_unparse_name(context, (*out_creds)->server, &unparsed);
if (ret) {
_krb5_debug(context, 5, "krb5_get_creds: unable to display "
"service principal");
} else {
_krb5_debug(context, 5, "krb5_get_creds: got a ticket for %s",
unparsed);
free(unparsed);
}
}
out:
krb5_free_creds(context, res_creds);
krb5_free_principal(context, in_creds.client);
krb5_free_name_canon_iterator(context, name_canon_iter);
if (ret)
return not_found(context, inprinc, ret);
return ret;
}
/*
*
*/
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_renewed_creds(krb5_context context,
krb5_creds *creds,
krb5_const_principal client,
krb5_ccache ccache,
const char *in_tkt_service)
{
krb5_error_code ret;
krb5_kdc_flags flags;
krb5_creds in, *template, *out = NULL;
memset(&in, 0, sizeof(in));
memset(creds, 0, sizeof(*creds));
ret = krb5_copy_principal(context, client, &in.client);
if (ret)
return ret;
if (in_tkt_service) {
ret = krb5_parse_name(context, in_tkt_service, &in.server);
if (ret) {
krb5_free_principal(context, in.client);
return ret;
}
} else {
const char *realm = krb5_principal_get_realm(context, client);
ret = krb5_make_principal(context, &in.server, realm, KRB5_TGS_NAME,
realm, NULL);
if (ret) {
krb5_free_principal(context, in.client);
return ret;
}
}
flags.i = 0;
flags.b.renewable = flags.b.renew = 1;
/*
* Get template from old credential cache for the same entry, if
* this failes, no worries.
*/
ret = krb5_get_credentials(context, KRB5_GC_CACHED, ccache, &in, &template);
if (ret == 0) {
flags.b.forwardable = template->flags.b.forwardable;
flags.b.proxiable = template->flags.b.proxiable;
krb5_free_creds (context, template);
}
ret = krb5_get_kdc_cred(context, ccache, flags, NULL, NULL, &in, &out);
krb5_free_principal(context, in.client);
krb5_free_principal(context, in.server);
if (ret)
return ret;
ret = krb5_copy_creds_contents(context, out, creds);
krb5_free_creds(context, out);
return ret;
}