/*
* encrypted_init - initialize an encrypted key
*
* For a new key, use a random number for both the iv and data
* itself. For an old key, decrypt the hex encoded data.
*/
static int encrypted_init(struct encrypted_key_payload *epayload,
const char *key_desc, const char *format,
const char *master_desc, const char *datalen,
const char *hex_encoded_iv)
{
int ret = 0;
if (format && !strcmp(format, key_format_ecryptfs)) {
ret = valid_ecryptfs_desc(key_desc);
if (ret < 0)
return ret;
ecryptfs_fill_auth_tok((struct ecryptfs_auth_tok *)epayload->payload_data,
key_desc);
}
__ekey_init(epayload, format, master_desc, datalen);
if (!hex_encoded_iv) {
get_random_bytes(epayload->iv, ivsize);
get_random_bytes(epayload->decrypted_data,
epayload->decrypted_datalen);
} else
ret = encrypted_key_decrypt(epayload, format, hex_encoded_iv);
return ret;
}
/*
* encrypted_update - update the master key description
*
* Change the master key description for an existing encrypted key.
* The next read will return an encrypted datablob using the new
* master key description.
*
* On success, return 0. Otherwise return errno.
*/
static int encrypted_update(struct key *key, struct key_preparsed_payload *prep)
{
struct encrypted_key_payload *epayload = key->payload.data[0];
struct encrypted_key_payload *new_epayload;
char *buf;
char *new_master_desc = NULL;
const char *format = NULL;
size_t datalen = prep->datalen;
int ret = 0;
if (test_bit(KEY_FLAG_NEGATIVE, &key->flags))
return -ENOKEY;
if (datalen <= 0 || datalen > 32767 || !prep->data)
return -EINVAL;
buf = kmalloc(datalen + 1, GFP_KERNEL);
if (!buf)
return -ENOMEM;
buf[datalen] = 0;
memcpy(buf, prep->data, datalen);
ret = datablob_parse(buf, &format, &new_master_desc, NULL, NULL);
if (ret < 0)
goto out;
ret = valid_master_desc(new_master_desc, epayload->master_desc);
if (ret < 0)
goto out;
new_epayload = encrypted_key_alloc(key, epayload->format,
new_master_desc, epayload->datalen);
if (IS_ERR(new_epayload)) {
ret = PTR_ERR(new_epayload);
goto out;
}
__ekey_init(new_epayload, epayload->format, new_master_desc,
epayload->datalen);
memcpy(new_epayload->iv, epayload->iv, ivsize);
memcpy(new_epayload->payload_data, epayload->payload_data,
epayload->payload_datalen);
rcu_assign_keypointer(key, new_epayload);
call_rcu(&epayload->rcu, encrypted_rcu_free);
out:
kfree(buf);
return ret;
}
