krb5_error_code KRB5_LIB_FUNCTION
krb5_generate_seq_number(krb5_context context,
const krb5_keyblock *key,
uint32_t *seqno)
{
krb5_error_code ret;
krb5_keyblock *subkey;
uint32_t q;
u_char *p;
int i;
ret = krb5_generate_subkey (context, key, &subkey);
if (ret)
return ret;
q = 0;
for (p = (u_char *)subkey->keyvalue.data, i = 0;
i < subkey->keyvalue.length;
++i, ++p)
q = (q << 8) | *p;
q &= 0xffffffff;
*seqno = q;
krb5_free_keyblock (context, subkey);
return 0;
}
/*
* Construct a TGS request and return its ASN.1 encoding as well as the
* timestamp, nonce, and subkey used. The pacb_fn callback allows the caller
* to amend the request padata after the nonce and subkey are determined.
*/
krb5_error_code
k5_make_tgs_req(krb5_context context,
struct krb5int_fast_request_state *fast_state,
krb5_creds *tgt, krb5_flags kdcoptions,
krb5_address *const *addrs, krb5_pa_data **in_padata,
krb5_creds *desired, k5_pacb_fn pacb_fn, void *pacb_data,
krb5_data *req_asn1_out, krb5_timestamp *timestamp_out,
krb5_int32 *nonce_out, krb5_keyblock **subkey_out)
{
krb5_error_code ret;
krb5_kdc_req req;
krb5_data *authdata_asn1 = NULL, *req_body_asn1 = NULL;
krb5_data *ap_req_asn1 = NULL, *tgs_req_asn1 = NULL;
krb5_ticket *sec_ticket = NULL;
krb5_ticket *sec_ticket_arr[2];
krb5_timestamp time_now;
krb5_pa_data **padata = NULL, *pa;
krb5_keyblock *subkey = NULL;
krb5_enc_data authdata_enc;
krb5_enctype enctypes[2], *defenctypes = NULL;
size_t count, i;
*req_asn1_out = empty_data();
*timestamp_out = 0;
*nonce_out = 0;
*subkey_out = NULL;
memset(&req, 0, sizeof(req));
memset(&authdata_enc, 0, sizeof(authdata_enc));
/* tgt's client principal must match the desired client principal. */
if (!krb5_principal_compare(context, tgt->client, desired->client))
return KRB5_PRINC_NOMATCH;
/* tgt must be an actual credential, not a template. */
if (!tgt->ticket.length)
return KRB5_NO_TKT_SUPPLIED;
req.kdc_options = kdcoptions;
req.server = desired->server;
req.from = desired->times.starttime;
req.till = desired->times.endtime ? desired->times.endtime :
tgt->times.endtime;
req.rtime = desired->times.renew_till;
ret = krb5_timeofday(context, &time_now);
if (ret)
return ret;
*nonce_out = req.nonce = (krb5_int32)time_now;
*timestamp_out = time_now;
req.addresses = (krb5_address **)addrs;
/* Generate subkey. */
ret = krb5_generate_subkey(context, &tgt->keyblock, &subkey);
if (ret)
return ret;
TRACE_SEND_TGS_SUBKEY(context, subkey);
ret = krb5int_fast_tgs_armor(context, fast_state, subkey, &tgt->keyblock,
NULL, NULL);
if (ret)
goto cleanup;
if (desired->authdata != NULL) {
ret = encode_krb5_authdata(desired->authdata, &authdata_asn1);
if (ret)
goto cleanup;
ret = krb5_encrypt_helper(context, subkey,
KRB5_KEYUSAGE_TGS_REQ_AD_SUBKEY,
authdata_asn1, &authdata_enc);
if (ret)
goto cleanup;
req.authorization_data = authdata_enc;
}
if (desired->keyblock.enctype != ENCTYPE_NULL) {
if (!krb5_c_valid_enctype(desired->keyblock.enctype)) {
ret = KRB5_PROG_ETYPE_NOSUPP;
goto cleanup;
}
enctypes[0] = desired->keyblock.enctype;
enctypes[1] = ENCTYPE_NULL;
req.ktype = enctypes;
req.nktypes = 1;
} else {
/* Get the default TGS enctypes. */
ret = krb5_get_tgs_ktypes(context, desired->server, &defenctypes);
if (ret)
goto cleanup;
for (count = 0; defenctypes[count]; count++);
req.ktype = defenctypes;
req.nktypes = count;
}
TRACE_SEND_TGS_ETYPES(context, req.ktype);
if (kdcoptions & (KDC_OPT_ENC_TKT_IN_SKEY | KDC_OPT_CNAME_IN_ADDL_TKT)) {
if (desired->second_ticket.length == 0) {
ret = KRB5_NO_2ND_TKT;
goto cleanup;
}
ret = decode_krb5_ticket(&desired->second_ticket, &sec_ticket);
if (ret)
goto cleanup;
sec_ticket_arr[0] = sec_ticket;
sec_ticket_arr[1] = NULL;
req.second_ticket = sec_ticket_arr;
}
/* Encode the request body. */
ret = krb5int_fast_prep_req_body(context, fast_state, &req,
&req_body_asn1);
if (ret)
goto cleanup;
ret = tgs_construct_ap_req(context, req_body_asn1, tgt, subkey,
&ap_req_asn1);
if (ret)
goto cleanup;
for (count = 0; in_padata != NULL && in_padata[count] != NULL; count++);
/* Construct a padata array for the request, beginning with the ap-req. */
padata = k5calloc(count + 2, sizeof(krb5_pa_data *), &ret);
if (padata == NULL)
goto cleanup;
padata[0] = k5alloc(sizeof(krb5_pa_data), &ret);
if (padata[0] == NULL)
goto cleanup;
padata[0]->pa_type = KRB5_PADATA_AP_REQ;
padata[0]->contents = k5memdup(ap_req_asn1->data, ap_req_asn1->length,
&ret);
if (padata[0] == NULL)
goto cleanup;
padata[0]->length = ap_req_asn1->length;
/* Append copies of any other supplied padata. */
for (i = 0; in_padata != NULL && in_padata[i] != NULL; i++) {
pa = k5alloc(sizeof(krb5_pa_data), &ret);
if (pa == NULL)
goto cleanup;
pa->pa_type = in_padata[i]->pa_type;
pa->length = in_padata[i]->length;
pa->contents = k5memdup(in_padata[i]->contents, in_padata[i]->length,
&ret);
if (pa->contents == NULL)
goto cleanup;
padata[i + 1] = pa;
}
req.padata = padata;
if (pacb_fn != NULL) {
ret = (*pacb_fn)(context, subkey, &req, pacb_data);
if (ret)
goto cleanup;
}
/* Encode the TGS-REQ. Discard the krb5_data container. */
ret = krb5int_fast_prep_req(context, fast_state, &req, ap_req_asn1,
encode_krb5_tgs_req, &tgs_req_asn1);
if (ret)
goto cleanup;
*req_asn1_out = *tgs_req_asn1;
free(tgs_req_asn1);
tgs_req_asn1 = NULL;
*subkey_out = subkey;
subkey = NULL;
cleanup:
krb5_free_data(context, authdata_asn1);
krb5_free_data(context, req_body_asn1);
krb5_free_data(context, ap_req_asn1);
krb5_free_pa_data(context, req.padata);
krb5_free_ticket(context, sec_ticket);
krb5_free_data_contents(context, &authdata_enc.ciphertext);
krb5_free_keyblock(context, subkey);
free(defenctypes);
return ret;
}
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 = NULL;
ret = krb5_auth_con_init(context, &ac);
if(ret)
goto fail;
if (krb5_config_get_bool_default(context, NULL, FALSE,
"realms",
krbtgt->server->realm,
"tgs_require_subkey",
NULL))
{
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) {
if (key)
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 ? key : &krbtgt->session);
if (ret) {
if (key)
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) {
if (key)
krb5_free_keyblock (context, key);
krb5_auth_con_free(context, ac);
goto fail;
}
*subkey = key;
krb5_auth_con_free(context, ac);
}
fail:
if (ret) {
t->req_body.addresses = NULL;
free_TGS_REQ (t);
}
return ret;
}
