break out fast unwrap

This commit is contained in:
Love Hornquist Astrand
2011-05-12 21:10:52 -07:00
committed by Love Hörnquist Åstrand
parent b8c168e565
commit 333471097d

View File

@@ -192,3 +192,231 @@ _kdc_fast_mk_error(krb5_context context,
return ret; return ret;
} }
krb5_error_code
_kdc_fast_unwrap_request(kdc_request_t r)
{
krb5_crypto crypto_subkey = NULL, crypto_session = NULL;
krb5_principal armor_server = NULL;
hdb_entry_ex *armor_user = NULL;
krb5_data pepper1, pepper2;
PA_FX_FAST_REQUEST fxreq;
krb5_auth_context ac = NULL;
krb5_ticket *ticket = NULL;
krb5_flags ap_req_options;
Key *armor_key = NULL;
krb5_keyblock armorkey;
krb5_error_code ret;
krb5_ap_req ap_req;
unsigned char *buf;
KrbFastReq fastreq;
size_t len, size;
krb5_data data;
const PA_DATA *pa;
int i = 0;
pa = _kdc_find_padata(&r->req, &i, KRB5_PADATA_FX_FAST);
if (pa == NULL)
return 0;
ret = decode_PA_FX_FAST_REQUEST(pa->padata_value.data,
pa->padata_value.length,
&fxreq,
&len);
if (ret)
goto out;
if (len != pa->padata_value.length) {
ret = KRB5KDC_ERR_PREAUTH_FAILED;
goto out;
}
if (fxreq.element != choice_PA_FX_FAST_REQUEST_armored_data) {
kdc_log(r->context, r->config, 0,
"AS-REQ FAST contain unknown type");
ret = KRB5KDC_ERR_PREAUTH_FAILED;
goto out;
}
/* pull out armor key */
if (fxreq.u.armored_data.armor == NULL) {
kdc_log(r->context, r->config, 0,
"AS-REQ armor missing");
ret = KRB5KDC_ERR_PREAUTH_FAILED;
goto out;
}
if (fxreq.u.armored_data.armor->armor_type != 1) {
kdc_log(r->context, r->config, 0,
"AS-REQ armor type not ap-req");
ret = KRB5KDC_ERR_PREAUTH_FAILED;
goto out;
}
ret = krb5_decode_ap_req(r->context,
&fxreq.u.armored_data.armor->armor_value,
&ap_req);
if(ret) {
kdc_log(r->context, r->config, 0, "AP-REQ decode failed");
goto out;
}
/* Save that principal that was in the request */
ret = _krb5_principalname2krb5_principal(r->context,
&armor_server,
ap_req.ticket.sname,
ap_req.ticket.realm);
if (ret) {
free_AP_REQ(&ap_req);
goto out;
}
ret = _kdc_db_fetch(r->context, r->config, armor_server,
HDB_F_GET_SERVER, NULL, NULL, &armor_user);
if(ret == HDB_ERR_NOT_FOUND_HERE) {
kdc_log(r->context, r->config, 5,
"armor key does not have secrets at this KDC, "
"need to proxy");
ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
goto out;
} if(ret){
free_AP_REQ(&ap_req);
ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
goto out;
}
ret = hdb_enctype2key(r->context, &armor_user->entry,
ap_req.ticket.enc_part.etype,
&armor_key);
if (ret) {
free_AP_REQ(&ap_req);
goto out;
}
ret = krb5_verify_ap_req2(r->context, &ac,
&ap_req,
armor_server,
&armor_key->key,
0,
&ap_req_options,
&ticket,
KRB5_KU_AP_REQ_AUTH);
free_AP_REQ(&ap_req);
if (ret)
goto out;
if (ac->remote_subkey == NULL) {
krb5_auth_con_free(r->context, ac);
kdc_log(r->context, r->config, 0,
"FAST AP-REQ remote subkey missing");
ret = KRB5KDC_ERR_PREAUTH_FAILED;
goto out;
}
ret = krb5_crypto_init(r->context, ac->remote_subkey,
0, &crypto_subkey);
if (ret) {
krb5_auth_con_free(r->context, ac);
krb5_free_ticket(r->context, ticket);
goto out;
}
ret = krb5_crypto_init(r->context, &ticket->ticket.key,
0, &crypto_session);
krb5_free_ticket(r->context, ticket);
if (ret) {
krb5_auth_con_free(r->context, ac);
krb5_crypto_destroy(r->context, crypto_subkey);
goto out;
}
pepper1.data = "subkeyarmor";
pepper1.length = strlen(pepper1.data);
pepper2.data = "ticketarmor";
pepper2.length = strlen(pepper2.data);
ret = krb5_crypto_fx_cf2(r->context, crypto_subkey, crypto_session,
&pepper1, &pepper2,
ac->remote_subkey->keytype,
&armorkey);
krb5_crypto_destroy(r->context, crypto_subkey);
krb5_crypto_destroy(r->context, crypto_session);
krb5_auth_con_free(r->context, ac);
if (ret)
goto out;
ret = krb5_crypto_init(r->context, &armorkey, 0, &r->armor_crypto);
if (ret)
goto out;
krb5_free_keyblock_contents(r->context, &armorkey);
/* verify req-checksum of the outer body */
ASN1_MALLOC_ENCODE(KDC_REQ_BODY, buf, len, &r->req.req_body, &size, ret);
if (ret)
goto out;
if (size != len) {
ret = KRB5KDC_ERR_PREAUTH_FAILED;
goto out;
}
ret = krb5_verify_checksum(r->context, r->armor_crypto,
KRB5_KU_FAST_REQ_CHKSUM,
buf, len,
&fxreq.u.armored_data.req_checksum);
free(buf);
if (ret)
goto out;
ret = krb5_decrypt_EncryptedData(r->context, r->armor_crypto,
KRB5_KU_FAST_ENC,
&fxreq.u.armored_data.enc_fast_req,
&data);
if (ret)
goto out;
ret = decode_KrbFastReq(data.data, data.length, &fastreq, &size);
if (ret) {
krb5_data_free(&data);
goto out;
}
if (data.length != size) {
krb5_data_free(&data);
ret = KRB5KDC_ERR_PREAUTH_FAILED;
goto out;
}
krb5_data_free(&data);
free_KDC_REQ_BODY(&r->req.req_body);
ret = copy_KDC_REQ_BODY(&fastreq.req_body, &r->req.req_body);
if (ret)
goto out;
/* check for unsupported mandatory options */
if (FastOptions2int(fastreq.fast_options) & 0xfffc) {
kdc_log(r->context, r->config, 0,
"FAST unsupported mandatory option set");
ret = KRB5KDC_ERR_PREAUTH_FAILED;
goto out;
}
/* KDC MUST ignore outer pa data preauth-14 - 6.5.5 */
if (r->req.padata)
free_METHOD_DATA(r->req.padata);
else
ALLOC(r->req.padata);
ret = copy_METHOD_DATA(&fastreq.padata, r->req.padata);
if (ret)
goto out;
free_KrbFastReq(&fastreq);
free_PA_FX_FAST_REQUEST(&fxreq);
out:
if (armor_server)
krb5_free_principal(r->context, armor_server);
if(armor_user)
_kdc_free_ent(r->context, armor_user);
return ret;
}