freebsd-skq/crypto/heimdal/lib/krb5/get_cred.c

841 lines
21 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 <krb5_locl.h>
RCSID("$Id: get_cred.c,v 1.91 2002/09/04 21:12:46 joda Exp $");
/*
* 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,
krb5_key_usage usage)
{
u_char *buf;
size_t buf_size;
size_t len;
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,
usage
/* 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 *key)
{
if(authdata->len) {
size_t len;
unsigned char *buf;
krb5_crypto crypto;
krb5_error_code ret;
ASN1_MALLOC_ENCODE(AuthorizationData, buf, len, authdata, &len, ret);
if (ret)
return ret;
ALLOC(req_body->enc_authorization_data, 1);
if (req_body->enc_authorization_data == NULL) {
free (buf);
krb5_set_error_string(context, "malloc: out of memory");
return ENOMEM;
}
ret = krb5_crypto_init(context, key, 0, &crypto);
if (ret) {
free (buf);
free (req_body->enc_authorization_data);
return ret;
}
krb5_encrypt_EncryptedData(context,
crypto,
KRB5_KU_TGS_REQ_AUTH_DAT_SUBKEY,
/* KRB5_KU_TGS_REQ_AUTH_DAT_SESSION? */
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,
krb5_keyblock **subkey,
TGS_REQ *t,
krb5_key_usage usage)
{
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 = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
t->req_body.etype.val[0] = in_creds->session.keytype;
} else {
ret = krb5_init_etype(context,
&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;
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 = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
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;
/* 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 = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
*t->req_body.till = in_creds->times.endtime;
t->req_body.nonce = nonce;
if(second_ticket){
ALLOC(t->req_body.additional_tickets, 1);
if (t->req_body.additional_tickets == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
ALLOC_SEQ(t->req_body.additional_tickets, 1);
if (t->req_body.additional_tickets->val == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
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 = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
ALLOC_SEQ(t->padata, 1);
if (t->padata->val == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto fail;
}
{
krb5_auth_context ac;
krb5_keyblock *key;
ret = krb5_auth_con_init(context, &ac);
if(ret)
goto fail;
ret = krb5_generate_subkey (context, &krbtgt->session, &key);
if (ret) {
krb5_auth_con_free (context, ac);
goto fail;
}
ret = krb5_auth_con_setlocalsubkey(context, ac, key);
if (ret) {
krb5_free_keyblock (context, key);
krb5_auth_con_free (context, ac);
goto fail;
}
ret = set_auth_data (context, &t->req_body, &in_creds->authdata, key);
if (ret) {
krb5_free_keyblock (context, key);
krb5_auth_con_free (context, ac);
goto fail;
}
ret = make_pa_tgs_req(context,
ac,
&t->req_body,
t->padata->val,
krbtgt,
usage);
if(ret) {
krb5_free_keyblock (context, key);
krb5_auth_con_free(context, ac);
goto fail;
}
*subkey = key;
krb5_auth_con_free(context, ac);
}
fail:
if (ret)
/* XXX - don't free addresses? */
free_TGS_REQ (t);
return ret;
}
static krb5_error_code
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_make_principal(context,
&tmp_cred.server,
realm,
KRB5_TGS_NAME,
realm,
NULL);
if(ret)
return ret;
ret = krb5_get_credentials(context,
KRB5_GC_CACHED,
id,
&tmp_cred,
cred);
krb5_free_principal(context, tmp_cred.server);
if(ret)
return ret;
return 0;
}
/* DCE compatible decrypt proc */
static krb5_error_code
decrypt_tkt_with_subkey (krb5_context context,
krb5_keyblock *key,
krb5_key_usage usage,
krb5_const_pointer subkey,
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 && subkey){
/* DCE compat -- try to decrypt with subkey */
ret = krb5_crypto_init(context, (krb5_keyblock*)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);
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);
return ret;
}
static krb5_error_code
get_cred_kdc_usage(krb5_context context,
krb5_ccache id,
krb5_kdc_flags flags,
krb5_addresses *addresses,
krb5_creds *in_creds,
krb5_creds *krbtgt,
krb5_creds *out_creds,
krb5_key_usage usage)
{
TGS_REQ req;
krb5_data enc;
krb5_data resp;
krb5_kdc_rep rep;
KRB_ERROR error;
krb5_error_code ret;
unsigned nonce;
krb5_keyblock *subkey = NULL;
u_char *buf = NULL;
size_t buf_size;
size_t len;
Ticket second_ticket;
krb5_generate_random_block(&nonce, sizeof(nonce));
nonce &= 0xffffffff;
if(flags.b.enc_tkt_in_skey){
ret = decode_Ticket(in_creds->second_ticket.data,
in_creds->second_ticket.length,
&second_ticket, &len);
if(ret)
return ret;
}
ret = init_tgs_req (context,
id,
addresses,
flags,
flags.b.enc_tkt_in_skey ? &second_ticket : NULL,
in_creds,
krbtgt,
nonce,
&subkey,
&req,
usage);
if(flags.b.enc_tkt_in_skey)
free_Ticket(&second_ticket);
if (ret)
goto out;
ASN1_MALLOC_ENCODE(TGS_REQ, buf, buf_size, &req, &enc.length, ret);
if (ret)
goto out;
if(enc.length != buf_size)
krb5_abortx(context, "internal error in ASN.1 encoder");
/* don't free addresses */
req.req_body.addresses = NULL;
free_TGS_REQ(&req);
enc.data = buf + buf_size - enc.length;
if (ret)
goto out;
/*
* Send and receive
*/
ret = krb5_sendto_kdc (context, &enc,
&krbtgt->server->name.name_string.val[1], &resp);
if(ret)
goto out;
memset(&rep, 0, sizeof(rep));
if(decode_TGS_REP(resp.data, resp.length, &rep.kdc_rep, &len) == 0){
ret = krb5_copy_principal(context,
in_creds->client,
&out_creds->client);
if(ret)
goto out;
ret = krb5_copy_principal(context,
in_creds->server,
&out_creds->server);
if(ret)
goto out;
/* this should go someplace else */
out_creds->times.endtime = in_creds->times.endtime;
ret = _krb5_extract_ticket(context,
&rep,
out_creds,
&krbtgt->session,
NULL,
KRB5_KU_TGS_REP_ENC_PART_SESSION,
&krbtgt->addresses,
nonce,
TRUE,
flags.b.request_anonymous,
decrypt_tkt_with_subkey,
subkey);
krb5_free_kdc_rep(context, &rep);
if (ret)
goto out;
} 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.data && ((char*)resp.data)[0] == 4) {
ret = KRB5KRB_AP_ERR_V4_REPLY;
krb5_clear_error_string(context);
} else {
ret = KRB5KRB_AP_ERR_MSG_TYPE;
krb5_clear_error_string(context);
}
krb5_data_free(&resp);
out:
if(subkey){
krb5_free_keyblock_contents(context, subkey);
free(subkey);
}
if (buf)
free (buf);
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_creds *out_creds)
{
krb5_error_code ret;
ret = get_cred_kdc_usage(context, id, flags, addresses, in_creds,
krbtgt, out_creds, KRB5_KU_TGS_REQ_AUTH);
if (ret == KRB5KRB_AP_ERR_BAD_INTEGRITY) {
krb5_clear_error_string (context);
ret = get_cred_kdc_usage(context, id, flags, addresses, in_creds,
krbtgt, out_creds, KRB5_KU_AP_REQ_AUTH);
}
return ret;
}
/* same as above, just get local addresses first */
static krb5_error_code
get_cred_kdc_la(krb5_context context, krb5_ccache id, krb5_kdc_flags flags,
krb5_creds *in_creds, krb5_creds *krbtgt,
krb5_creds *out_creds)
{
krb5_error_code ret;
krb5_addresses addresses, *addrs = &addresses;
krb5_get_all_client_addrs(context, &addresses);
/* XXX this sucks. */
if(addresses.len == 0)
addrs = NULL;
ret = get_cred_kdc(context, id, flags, addrs,
in_creds, krbtgt, out_creds);
krb5_free_addresses(context, &addresses);
return ret;
}
krb5_error_code
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) {
krb5_set_error_string(context, "malloc: out of memory");
return ENOMEM;
}
ret = get_krbtgt (context,
id,
in_creds->server->realm,
&krbtgt);
if(ret) {
free(*out_creds);
return ret;
}
ret = get_cred_kdc(context, id, flags, addresses,
in_creds, krbtgt, *out_creds);
krb5_free_creds (context, krbtgt);
if(ret)
free(*out_creds);
return ret;
}
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;
mcreds.server = server;
ret = krb5_cc_retrieve_cred(context, id, KRB5_TC_DONT_MATCH_REALM,
&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++;
}
krb5_clear_error_string(context);
return KRB5_CC_NOTFOUND;
}
static krb5_error_code
add_cred(krb5_context context, krb5_creds ***tgts, krb5_creds *tkt)
{
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) {
krb5_set_error_string(context, "malloc: out of memory");
return ENOMEM;
}
*tgts = tmp;
ret = krb5_copy_creds(context, tkt, &tmp[i]);
tmp[i+1] = NULL;
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_from_kdc_flags(krb5_context context,
krb5_kdc_flags flags,
krb5_ccache ccache,
krb5_creds *in_creds,
krb5_creds **out_creds,
krb5_creds ***ret_tgts)
{
krb5_error_code ret;
krb5_creds *tgt, tmp_creds;
krb5_const_realm client_realm, server_realm, try_realm;
*out_creds = NULL;
client_realm = *krb5_princ_realm(context, in_creds->client);
server_realm = *krb5_princ_realm(context, in_creds->server);
memset(&tmp_creds, 0, sizeof(tmp_creds));
ret = krb5_copy_principal(context, in_creds->client, &tmp_creds.client);
if(ret)
return ret;
try_realm = krb5_config_get_string(context, NULL, "libdefaults",
"capath", server_realm, NULL);
if (try_realm == NULL)
try_realm = client_realm;
ret = krb5_make_principal(context,
&tmp_creds.server,
try_realm,
KRB5_TGS_NAME,
server_realm,
NULL);
if(ret){
krb5_free_principal(context, tmp_creds.client);
return ret;
}
{
krb5_creds tgts;
/* XXX try krb5_cc_retrieve_cred first? */
ret = find_cred(context, ccache, tmp_creds.server,
*ret_tgts, &tgts);
if(ret == 0){
*out_creds = calloc(1, sizeof(**out_creds));
if(*out_creds == NULL) {
krb5_set_error_string(context, "malloc: out of memory");
ret = ENOMEM;
} else {
krb5_boolean noaddr;
krb5_appdefault_boolean(context, NULL, tgts.server->realm,
"no-addresses", FALSE, &noaddr);
if (noaddr)
ret = get_cred_kdc(context, ccache, flags, NULL,
in_creds, &tgts, *out_creds);
else
ret = get_cred_kdc_la(context, ccache, flags,
in_creds, &tgts, *out_creds);
if (ret) {
free (*out_creds);
*out_creds = NULL;
}
}
krb5_free_creds_contents(context, &tgts);
krb5_free_principal(context, tmp_creds.server);
krb5_free_principal(context, tmp_creds.client);
return ret;
}
}
if(krb5_realm_compare(context, in_creds->client, in_creds->server)) {
krb5_clear_error_string (context);
return KRB5_CC_NOTFOUND;
}
/* XXX this can loop forever */
while(1){
general_string tgt_inst;
ret = get_cred_from_kdc_flags(context, flags, ccache, &tmp_creds,
&tgt, ret_tgts);
if(ret) {
krb5_free_principal(context, tmp_creds.server);
krb5_free_principal(context, tmp_creds.client);
return ret;
}
ret = add_cred(context, ret_tgts, tgt);
if(ret) {
krb5_free_principal(context, tmp_creds.server);
krb5_free_principal(context, tmp_creds.client);
return ret;
}
tgt_inst = tgt->server->name.name_string.val[1];
if(strcmp(tgt_inst, server_realm) == 0)
break;
krb5_free_principal(context, tmp_creds.server);
ret = krb5_make_principal(context, &tmp_creds.server,
tgt_inst, KRB5_TGS_NAME, server_realm, NULL);
if(ret) {
krb5_free_principal(context, tmp_creds.server);
krb5_free_principal(context, tmp_creds.client);
return ret;
}
ret = krb5_free_creds(context, tgt);
if(ret) {
krb5_free_principal(context, tmp_creds.server);
krb5_free_principal(context, tmp_creds.client);
return ret;
}
}
krb5_free_principal(context, tmp_creds.server);
krb5_free_principal(context, tmp_creds.client);
*out_creds = calloc(1, sizeof(**out_creds));
if(*out_creds == NULL) {
krb5_set_error_string(context, "malloc: out of memory");
ret = ENOMEM;
} else {
krb5_boolean noaddr;
krb5_appdefault_boolean(context, NULL, tgt->server->realm,
"no-addresses", FALSE, &noaddr);
if (noaddr)
ret = get_cred_kdc (context, ccache, flags, NULL,
in_creds, tgt, *out_creds);
else
ret = get_cred_kdc_la(context, ccache, flags,
in_creds, tgt, *out_creds);
if (ret) {
free (*out_creds);
*out_creds = NULL;
}
}
krb5_free_creds(context, tgt);
return ret;
}
krb5_error_code
krb5_get_cred_from_kdc_opt(krb5_context context,
krb5_ccache ccache,
krb5_creds *in_creds,
krb5_creds **out_creds,
krb5_creds ***ret_tgts,
krb5_flags flags)
{
krb5_kdc_flags f;
f.i = flags;
return get_cred_from_kdc_flags(context, f, ccache,
in_creds, out_creds, ret_tgts);
}
krb5_error_code
krb5_get_cred_from_kdc(krb5_context context,
krb5_ccache ccache,
krb5_creds *in_creds,
krb5_creds **out_creds,
krb5_creds ***ret_tgts)
{
return krb5_get_cred_from_kdc_opt(context, ccache,
in_creds, out_creds, ret_tgts, 0);
}
krb5_error_code
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_creds **tgts;
krb5_creds *res_creds;
int i;
*out_creds = NULL;
res_creds = calloc(1, sizeof(*res_creds));
if (res_creds == NULL) {
krb5_set_error_string(context, "malloc: out of memory");
return ENOMEM;
}
ret = krb5_cc_retrieve_cred(context,
ccache,
in_creds->session.keytype ?
KRB5_TC_MATCH_KEYTYPE : 0,
in_creds, res_creds);
if(ret == 0) {
*out_creds = res_creds;
return 0;
}
free(res_creds);
if(ret != KRB5_CC_END)
return ret;
if(options & KRB5_GC_CACHED) {
krb5_clear_error_string (context);
return KRB5_CC_NOTFOUND;
}
if(options & KRB5_GC_USER_USER)
flags.b.enc_tkt_in_skey = 1;
tgts = NULL;
ret = get_cred_from_kdc_flags(context, flags, ccache,
in_creds, out_creds, &tgts);
for(i = 0; tgts && tgts[i]; i++) {
krb5_cc_store_cred(context, ccache, tgts[i]);
krb5_free_creds(context, tgts[i]);
}
free(tgts);
if(ret == 0 && flags.b.enc_tkt_in_skey == 0)
krb5_cc_store_cred(context, ccache, *out_creds);
return ret;
}
krb5_error_code
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);
}