2021-03-01 13:11:24 +00:00
|
|
|
// SPDX-License-Identifier: GPL-2.0-only
|
|
|
|
/*
|
|
|
|
* Copyright (C) 2010 IBM Corporation
|
|
|
|
* Copyright (c) 2019-2021, Linaro Limited
|
|
|
|
*
|
|
|
|
* See Documentation/security/keys/trusted-encrypted.rst
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include <keys/user-type.h>
|
|
|
|
#include <keys/trusted-type.h>
|
2021-03-01 13:11:25 +00:00
|
|
|
#include <keys/trusted_tee.h>
|
2021-03-01 13:11:24 +00:00
|
|
|
#include <keys/trusted_tpm.h>
|
|
|
|
#include <linux/capability.h>
|
|
|
|
#include <linux/err.h>
|
|
|
|
#include <linux/init.h>
|
|
|
|
#include <linux/key-type.h>
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/parser.h>
|
|
|
|
#include <linux/rcupdate.h>
|
|
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/static_call.h>
|
|
|
|
#include <linux/string.h>
|
|
|
|
#include <linux/uaccess.h>
|
|
|
|
|
|
|
|
static char *trusted_key_source;
|
|
|
|
module_param_named(source, trusted_key_source, charp, 0);
|
|
|
|
MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)");
|
|
|
|
|
|
|
|
static const struct trusted_key_source trusted_key_sources[] = {
|
|
|
|
#if defined(CONFIG_TCG_TPM)
|
|
|
|
{ "tpm", &trusted_key_tpm_ops },
|
|
|
|
#endif
|
2021-03-01 13:11:25 +00:00
|
|
|
#if defined(CONFIG_TEE)
|
|
|
|
{ "tee", &trusted_key_tee_ops },
|
|
|
|
#endif
|
2021-03-01 13:11:24 +00:00
|
|
|
};
|
|
|
|
|
|
|
|
DEFINE_STATIC_CALL_NULL(trusted_key_init, *trusted_key_sources[0].ops->init);
|
|
|
|
DEFINE_STATIC_CALL_NULL(trusted_key_seal, *trusted_key_sources[0].ops->seal);
|
|
|
|
DEFINE_STATIC_CALL_NULL(trusted_key_unseal,
|
|
|
|
*trusted_key_sources[0].ops->unseal);
|
|
|
|
DEFINE_STATIC_CALL_NULL(trusted_key_get_random,
|
|
|
|
*trusted_key_sources[0].ops->get_random);
|
|
|
|
DEFINE_STATIC_CALL_NULL(trusted_key_exit, *trusted_key_sources[0].ops->exit);
|
|
|
|
static unsigned char migratable;
|
|
|
|
|
|
|
|
enum {
|
|
|
|
Opt_err,
|
|
|
|
Opt_new, Opt_load, Opt_update,
|
|
|
|
};
|
|
|
|
|
|
|
|
static const match_table_t key_tokens = {
|
|
|
|
{Opt_new, "new"},
|
|
|
|
{Opt_load, "load"},
|
|
|
|
{Opt_update, "update"},
|
|
|
|
{Opt_err, NULL}
|
|
|
|
};
|
|
|
|
|
|
|
|
/*
|
|
|
|
* datablob_parse - parse the keyctl data and fill in the
|
|
|
|
* payload structure
|
|
|
|
*
|
|
|
|
* On success returns 0, otherwise -EINVAL.
|
|
|
|
*/
|
|
|
|
static int datablob_parse(char *datablob, struct trusted_key_payload *p)
|
|
|
|
{
|
|
|
|
substring_t args[MAX_OPT_ARGS];
|
|
|
|
long keylen;
|
|
|
|
int ret = -EINVAL;
|
|
|
|
int key_cmd;
|
|
|
|
char *c;
|
|
|
|
|
|
|
|
/* main command */
|
|
|
|
c = strsep(&datablob, " \t");
|
|
|
|
if (!c)
|
|
|
|
return -EINVAL;
|
|
|
|
key_cmd = match_token(c, key_tokens, args);
|
|
|
|
switch (key_cmd) {
|
|
|
|
case Opt_new:
|
|
|
|
/* first argument is key size */
|
|
|
|
c = strsep(&datablob, " \t");
|
|
|
|
if (!c)
|
|
|
|
return -EINVAL;
|
|
|
|
ret = kstrtol(c, 10, &keylen);
|
|
|
|
if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
|
|
|
|
return -EINVAL;
|
|
|
|
p->key_len = keylen;
|
|
|
|
ret = Opt_new;
|
|
|
|
break;
|
|
|
|
case Opt_load:
|
|
|
|
/* first argument is sealed blob */
|
|
|
|
c = strsep(&datablob, " \t");
|
|
|
|
if (!c)
|
|
|
|
return -EINVAL;
|
|
|
|
p->blob_len = strlen(c) / 2;
|
|
|
|
if (p->blob_len > MAX_BLOB_SIZE)
|
|
|
|
return -EINVAL;
|
|
|
|
ret = hex2bin(p->blob, c, p->blob_len);
|
|
|
|
if (ret < 0)
|
|
|
|
return -EINVAL;
|
|
|
|
ret = Opt_load;
|
|
|
|
break;
|
|
|
|
case Opt_update:
|
|
|
|
ret = Opt_update;
|
|
|
|
break;
|
|
|
|
case Opt_err:
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
|
|
|
|
{
|
|
|
|
struct trusted_key_payload *p = NULL;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
ret = key_payload_reserve(key, sizeof(*p));
|
|
|
|
if (ret < 0)
|
|
|
|
return p;
|
|
|
|
p = kzalloc(sizeof(*p), GFP_KERNEL);
|
|
|
|
|
|
|
|
p->migratable = migratable;
|
|
|
|
|
|
|
|
return p;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* trusted_instantiate - create a new trusted key
|
|
|
|
*
|
|
|
|
* Unseal an existing trusted blob or, for a new key, get a
|
|
|
|
* random key, then seal and create a trusted key-type key,
|
|
|
|
* adding it to the specified keyring.
|
|
|
|
*
|
|
|
|
* On success, return 0. Otherwise return errno.
|
|
|
|
*/
|
|
|
|
static int trusted_instantiate(struct key *key,
|
|
|
|
struct key_preparsed_payload *prep)
|
|
|
|
{
|
|
|
|
struct trusted_key_payload *payload = NULL;
|
|
|
|
size_t datalen = prep->datalen;
|
|
|
|
char *datablob;
|
|
|
|
int ret = 0;
|
|
|
|
int key_cmd;
|
|
|
|
size_t key_len;
|
|
|
|
|
|
|
|
if (datalen <= 0 || datalen > 32767 || !prep->data)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
datablob = kmalloc(datalen + 1, GFP_KERNEL);
|
|
|
|
if (!datablob)
|
|
|
|
return -ENOMEM;
|
|
|
|
memcpy(datablob, prep->data, datalen);
|
|
|
|
datablob[datalen] = '\0';
|
|
|
|
|
|
|
|
payload = trusted_payload_alloc(key);
|
|
|
|
if (!payload) {
|
|
|
|
ret = -ENOMEM;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
|
|
|
key_cmd = datablob_parse(datablob, payload);
|
|
|
|
if (key_cmd < 0) {
|
|
|
|
ret = key_cmd;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
|
|
|
dump_payload(payload);
|
|
|
|
|
|
|
|
switch (key_cmd) {
|
|
|
|
case Opt_load:
|
|
|
|
ret = static_call(trusted_key_unseal)(payload, datablob);
|
|
|
|
dump_payload(payload);
|
|
|
|
if (ret < 0)
|
|
|
|
pr_info("key_unseal failed (%d)\n", ret);
|
|
|
|
break;
|
|
|
|
case Opt_new:
|
|
|
|
key_len = payload->key_len;
|
|
|
|
ret = static_call(trusted_key_get_random)(payload->key,
|
|
|
|
key_len);
|
|
|
|
if (ret < 0)
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
if (ret != key_len) {
|
|
|
|
pr_info("key_create failed (%d)\n", ret);
|
|
|
|
ret = -EIO;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
|
|
|
ret = static_call(trusted_key_seal)(payload, datablob);
|
|
|
|
if (ret < 0)
|
|
|
|
pr_info("key_seal failed (%d)\n", ret);
|
|
|
|
break;
|
|
|
|
default:
|
|
|
|
ret = -EINVAL;
|
|
|
|
}
|
|
|
|
out:
|
|
|
|
kfree_sensitive(datablob);
|
|
|
|
if (!ret)
|
|
|
|
rcu_assign_keypointer(key, payload);
|
|
|
|
else
|
|
|
|
kfree_sensitive(payload);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void trusted_rcu_free(struct rcu_head *rcu)
|
|
|
|
{
|
|
|
|
struct trusted_key_payload *p;
|
|
|
|
|
|
|
|
p = container_of(rcu, struct trusted_key_payload, rcu);
|
|
|
|
kfree_sensitive(p);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* trusted_update - reseal an existing key with new PCR values
|
|
|
|
*/
|
|
|
|
static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
|
|
|
|
{
|
|
|
|
struct trusted_key_payload *p;
|
|
|
|
struct trusted_key_payload *new_p;
|
|
|
|
size_t datalen = prep->datalen;
|
|
|
|
char *datablob;
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
if (key_is_negative(key))
|
|
|
|
return -ENOKEY;
|
|
|
|
p = key->payload.data[0];
|
|
|
|
if (!p->migratable)
|
|
|
|
return -EPERM;
|
|
|
|
if (datalen <= 0 || datalen > 32767 || !prep->data)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
datablob = kmalloc(datalen + 1, GFP_KERNEL);
|
|
|
|
if (!datablob)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
new_p = trusted_payload_alloc(key);
|
|
|
|
if (!new_p) {
|
|
|
|
ret = -ENOMEM;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
|
|
|
memcpy(datablob, prep->data, datalen);
|
|
|
|
datablob[datalen] = '\0';
|
|
|
|
ret = datablob_parse(datablob, new_p);
|
|
|
|
if (ret != Opt_update) {
|
|
|
|
ret = -EINVAL;
|
|
|
|
kfree_sensitive(new_p);
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* copy old key values, and reseal with new pcrs */
|
|
|
|
new_p->migratable = p->migratable;
|
|
|
|
new_p->key_len = p->key_len;
|
|
|
|
memcpy(new_p->key, p->key, p->key_len);
|
|
|
|
dump_payload(p);
|
|
|
|
dump_payload(new_p);
|
|
|
|
|
|
|
|
ret = static_call(trusted_key_seal)(new_p, datablob);
|
|
|
|
if (ret < 0) {
|
|
|
|
pr_info("key_seal failed (%d)\n", ret);
|
|
|
|
kfree_sensitive(new_p);
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
|
|
|
rcu_assign_keypointer(key, new_p);
|
|
|
|
call_rcu(&p->rcu, trusted_rcu_free);
|
|
|
|
out:
|
|
|
|
kfree_sensitive(datablob);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* trusted_read - copy the sealed blob data to userspace in hex.
|
|
|
|
* On success, return to userspace the trusted key datablob size.
|
|
|
|
*/
|
|
|
|
static long trusted_read(const struct key *key, char *buffer,
|
|
|
|
size_t buflen)
|
|
|
|
{
|
|
|
|
const struct trusted_key_payload *p;
|
|
|
|
char *bufp;
|
|
|
|
int i;
|
|
|
|
|
|
|
|
p = dereference_key_locked(key);
|
|
|
|
if (!p)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
if (buffer && buflen >= 2 * p->blob_len) {
|
|
|
|
bufp = buffer;
|
|
|
|
for (i = 0; i < p->blob_len; i++)
|
|
|
|
bufp = hex_byte_pack(bufp, p->blob[i]);
|
|
|
|
}
|
|
|
|
return 2 * p->blob_len;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* trusted_destroy - clear and free the key's payload
|
|
|
|
*/
|
|
|
|
static void trusted_destroy(struct key *key)
|
|
|
|
{
|
|
|
|
kfree_sensitive(key->payload.data[0]);
|
|
|
|
}
|
|
|
|
|
|
|
|
struct key_type key_type_trusted = {
|
|
|
|
.name = "trusted",
|
|
|
|
.instantiate = trusted_instantiate,
|
|
|
|
.update = trusted_update,
|
|
|
|
.destroy = trusted_destroy,
|
|
|
|
.describe = user_describe,
|
|
|
|
.read = trusted_read,
|
|
|
|
};
|
|
|
|
EXPORT_SYMBOL_GPL(key_type_trusted);
|
|
|
|
|
|
|
|
static int __init init_trusted(void)
|
|
|
|
{
|
|
|
|
int i, ret = 0;
|
|
|
|
|
|
|
|
for (i = 0; i < ARRAY_SIZE(trusted_key_sources); i++) {
|
|
|
|
if (trusted_key_source &&
|
|
|
|
strncmp(trusted_key_source, trusted_key_sources[i].name,
|
|
|
|
strlen(trusted_key_sources[i].name)))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
static_call_update(trusted_key_init,
|
|
|
|
trusted_key_sources[i].ops->init);
|
|
|
|
static_call_update(trusted_key_seal,
|
|
|
|
trusted_key_sources[i].ops->seal);
|
|
|
|
static_call_update(trusted_key_unseal,
|
|
|
|
trusted_key_sources[i].ops->unseal);
|
|
|
|
static_call_update(trusted_key_get_random,
|
|
|
|
trusted_key_sources[i].ops->get_random);
|
|
|
|
static_call_update(trusted_key_exit,
|
|
|
|
trusted_key_sources[i].ops->exit);
|
|
|
|
migratable = trusted_key_sources[i].ops->migratable;
|
|
|
|
|
|
|
|
ret = static_call(trusted_key_init)();
|
|
|
|
if (!ret)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* encrypted_keys.ko depends on successful load of this module even if
|
|
|
|
* trusted key implementation is not found.
|
|
|
|
*/
|
|
|
|
if (ret == -ENODEV)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void __exit cleanup_trusted(void)
|
|
|
|
{
|
|
|
|
static_call(trusted_key_exit)();
|
|
|
|
}
|
|
|
|
|
|
|
|
late_initcall(init_trusted);
|
|
|
|
module_exit(cleanup_trusted);
|
|
|
|
|
|
|
|
MODULE_LICENSE("GPL");
|