/*
* LUKS - Linux Unified Key Setup v2, kernel keyring token
*
* Copyright (C) 2016-2020 Red Hat, Inc. All rights reserved.
* Copyright (C) 2016-2020 Ondrej Kozina
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <assert.h>
#include "luks2_internal.h"
static int keyring_open(struct crypt_device *cd,
int token,
char **buffer,
size_t *buffer_len,
void *usrptr __attribute__((unused)))
{
json_object *jobj_token, *jobj_key;
struct luks2_hdr *hdr;
int r;
if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
return -EINVAL;
jobj_token = LUKS2_get_token_jobj(hdr, token);
if (!jobj_token)
return -EINVAL;
json_object_object_get_ex(jobj_token, "key_description", &jobj_key);
r = keyring_get_passphrase(json_object_get_string(jobj_key), buffer, buffer_len);
if (r == -ENOTSUP) {
log_dbg(cd, "Kernel keyring features disabled.");
return -EINVAL;
} else if (r < 0) {
log_dbg(cd, "keyring_get_passphrase failed (error %d)", r);
return -EINVAL;
}
return 0;
}
static int keyring_validate(struct crypt_device *cd __attribute__((unused)),
const char *json)
{
enum json_tokener_error jerr;
json_object *jobj_token, *jobj_key;
int r = 1;
log_dbg(cd, "Validating keyring token json");
jobj_token = json_tokener_parse_verbose(json, &jerr);
if (!jobj_token) {
log_dbg(cd, "Keyring token JSON parse failed.");
return r;
}
if (json_object_object_length(jobj_token) != 3) {
log_dbg(cd, "Keyring token is expected to have exactly 3 fields.");
goto out;
}
if (!json_object_object_get_ex(jobj_token, "key_description", &jobj_key)) {
log_dbg(cd, "missing key_description field.");
goto out;
}
if (!json_object_is_type(jobj_key, json_type_string)) {
log_dbg(cd, "key_description is not a string.");
goto out;
}
/* TODO: perhaps check that key description is in '%s:%s'
* format where both strings are not empty */
r = !strlen(json_object_get_string(jobj_key));
out:
json_object_put(jobj_token);
return r;
}
static void keyring_dump(struct crypt_device *cd, const char *json)
{
enum json_tokener_error jerr;
json_object *jobj_token, *jobj_key;
jobj_token = json_tokener_parse_verbose(json, &jerr);
if (!jobj_token)
return;
if (!json_object_object_get_ex(jobj_token, "key_description", &jobj_key)) {
json_object_put(jobj_token);
return;
}
log_std(cd, "\tKey description: %s\n", json_object_get_string(jobj_key));
json_object_put(jobj_token);
}
int token_keyring_set(json_object **jobj_builtin_token,
const void *params)
{
json_object *jobj_token, *jobj;
const struct crypt_token_params_luks2_keyring *keyring_params = (const struct crypt_token_params_luks2_keyring *) params;
jobj_token = json_object_new_object();
if (!jobj_token)
return -ENOMEM;
jobj = json_object_new_string(LUKS2_TOKEN_KEYRING);
if (!jobj) {
json_object_put(jobj_token);
return -ENOMEM;
}
json_object_object_add(jobj_token, "type", jobj);
jobj = json_object_new_array();
if (!jobj) {
json_object_put(jobj_token);
return -ENOMEM;
}
json_object_object_add(jobj_token, "keyslots", jobj);
jobj = json_object_new_string(keyring_params->key_description);
if (!jobj) {
json_object_put(jobj_token);
return -ENOMEM;
}
json_object_object_add(jobj_token, "key_description", jobj);
*jobj_builtin_token = jobj_token;
return 0;
}
int token_keyring_get(json_object *jobj_token,
void *params)
{
json_object *jobj;
struct crypt_token_params_luks2_keyring *keyring_params = (struct crypt_token_params_luks2_keyring *) params;
json_object_object_get_ex(jobj_token, "type", &jobj);
assert(!strcmp(json_object_get_string(jobj), LUKS2_TOKEN_KEYRING));
json_object_object_get_ex(jobj_token, "key_description", &jobj);
keyring_params->key_description = json_object_get_string(jobj);
return 0;
}
const crypt_token_handler keyring_handler = {
.name = LUKS2_TOKEN_KEYRING,
.open = keyring_open,
.validate = keyring_validate,
.dump = keyring_dump
};