1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2019-2021 Linaro Ltd.
6 * Sumit Garg <sumit.garg@linaro.org>
10 #include <linux/key-type.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/string.h>
14 #include <linux/tee_drv.h>
15 #include <linux/uuid.h>
17 #include <keys/trusted_tee.h>
19 #define DRIVER_NAME "trusted-key-tee"
22 * Get random data for symmetric key
24 * [out] memref[0] Random data
26 #define TA_CMD_GET_RANDOM 0x0
29 * Seal trusted key using hardware unique key
31 * [in] memref[0] Plain key
32 * [out] memref[1] Sealed key datablob
34 #define TA_CMD_SEAL 0x1
37 * Unseal trusted key using hardware unique key
39 * [in] memref[0] Sealed key datablob
40 * [out] memref[1] Plain key
42 #define TA_CMD_UNSEAL 0x2
45 * struct trusted_key_tee_private - TEE Trusted key private data
46 * @dev: TEE based Trusted key device.
47 * @ctx: TEE context handler.
48 * @session_id: Trusted key TA session identifier.
49 * @shm_pool: Memory pool shared with TEE device.
51 struct trusted_key_tee_private {
53 struct tee_context *ctx;
55 struct tee_shm *shm_pool;
58 static struct trusted_key_tee_private pvt_data;
61 * Have the TEE seal(encrypt) the symmetric key
63 static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
66 struct tee_ioctl_invoke_arg inv_arg;
67 struct tee_param param[4];
68 struct tee_shm *reg_shm = NULL;
70 memset(&inv_arg, 0, sizeof(inv_arg));
71 memset(¶m, 0, sizeof(param));
73 reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, p->key,
74 sizeof(p->key) + sizeof(p->blob));
75 if (IS_ERR(reg_shm)) {
76 dev_err(pvt_data.dev, "shm register failed\n");
77 return PTR_ERR(reg_shm);
80 inv_arg.func = TA_CMD_SEAL;
81 inv_arg.session = pvt_data.session_id;
82 inv_arg.num_params = 4;
84 param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
85 param[0].u.memref.shm = reg_shm;
86 param[0].u.memref.size = p->key_len;
87 param[0].u.memref.shm_offs = 0;
88 param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
89 param[1].u.memref.shm = reg_shm;
90 param[1].u.memref.size = sizeof(p->blob);
91 param[1].u.memref.shm_offs = sizeof(p->key);
93 ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
94 if ((ret < 0) || (inv_arg.ret != 0)) {
95 dev_err(pvt_data.dev, "TA_CMD_SEAL invoke err: %x\n",
99 p->blob_len = param[1].u.memref.size;
102 tee_shm_free(reg_shm);
108 * Have the TEE unseal(decrypt) the symmetric key
110 static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
113 struct tee_ioctl_invoke_arg inv_arg;
114 struct tee_param param[4];
115 struct tee_shm *reg_shm = NULL;
117 memset(&inv_arg, 0, sizeof(inv_arg));
118 memset(¶m, 0, sizeof(param));
120 reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, p->key,
121 sizeof(p->key) + sizeof(p->blob));
122 if (IS_ERR(reg_shm)) {
123 dev_err(pvt_data.dev, "shm register failed\n");
124 return PTR_ERR(reg_shm);
127 inv_arg.func = TA_CMD_UNSEAL;
128 inv_arg.session = pvt_data.session_id;
129 inv_arg.num_params = 4;
131 param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
132 param[0].u.memref.shm = reg_shm;
133 param[0].u.memref.size = p->blob_len;
134 param[0].u.memref.shm_offs = sizeof(p->key);
135 param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
136 param[1].u.memref.shm = reg_shm;
137 param[1].u.memref.size = sizeof(p->key);
138 param[1].u.memref.shm_offs = 0;
140 ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
141 if ((ret < 0) || (inv_arg.ret != 0)) {
142 dev_err(pvt_data.dev, "TA_CMD_UNSEAL invoke err: %x\n",
146 p->key_len = param[1].u.memref.size;
149 tee_shm_free(reg_shm);
155 * Have the TEE generate random symmetric key
157 static int trusted_tee_get_random(unsigned char *key, size_t key_len)
160 struct tee_ioctl_invoke_arg inv_arg;
161 struct tee_param param[4];
162 struct tee_shm *reg_shm = NULL;
164 memset(&inv_arg, 0, sizeof(inv_arg));
165 memset(¶m, 0, sizeof(param));
167 reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, key, key_len);
168 if (IS_ERR(reg_shm)) {
169 dev_err(pvt_data.dev, "key shm register failed\n");
170 return PTR_ERR(reg_shm);
173 inv_arg.func = TA_CMD_GET_RANDOM;
174 inv_arg.session = pvt_data.session_id;
175 inv_arg.num_params = 4;
177 param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
178 param[0].u.memref.shm = reg_shm;
179 param[0].u.memref.size = key_len;
180 param[0].u.memref.shm_offs = 0;
182 ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
183 if ((ret < 0) || (inv_arg.ret != 0)) {
184 dev_err(pvt_data.dev, "TA_CMD_GET_RANDOM invoke err: %x\n",
188 ret = param[0].u.memref.size;
191 tee_shm_free(reg_shm);
196 static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
198 if (ver->impl_id == TEE_IMPL_ID_OPTEE &&
199 ver->gen_caps & TEE_GEN_CAP_REG_MEM)
205 static int trusted_key_probe(struct device *dev)
207 struct tee_client_device *rng_device = to_tee_client_device(dev);
209 struct tee_ioctl_open_session_arg sess_arg;
211 memset(&sess_arg, 0, sizeof(sess_arg));
213 pvt_data.ctx = tee_client_open_context(NULL, optee_ctx_match, NULL,
215 if (IS_ERR(pvt_data.ctx))
218 memcpy(sess_arg.uuid, rng_device->id.uuid.b, TEE_IOCTL_UUID_LEN);
219 sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
220 sess_arg.num_params = 0;
222 ret = tee_client_open_session(pvt_data.ctx, &sess_arg, NULL);
223 if ((ret < 0) || (sess_arg.ret != 0)) {
224 dev_err(dev, "tee_client_open_session failed, err: %x\n",
229 pvt_data.session_id = sess_arg.session;
231 ret = register_key_type(&key_type_trusted);
240 tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
242 tee_client_close_context(pvt_data.ctx);
247 static int trusted_key_remove(struct device *dev)
249 unregister_key_type(&key_type_trusted);
250 tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
251 tee_client_close_context(pvt_data.ctx);
256 static const struct tee_client_device_id trusted_key_id_table[] = {
257 {UUID_INIT(0xf04a0fe7, 0x1f5d, 0x4b9b,
258 0xab, 0xf7, 0x61, 0x9b, 0x85, 0xb4, 0xce, 0x8c)},
261 MODULE_DEVICE_TABLE(tee, trusted_key_id_table);
263 static struct tee_client_driver trusted_key_driver = {
264 .id_table = trusted_key_id_table,
267 .bus = &tee_bus_type,
268 .probe = trusted_key_probe,
269 .remove = trusted_key_remove,
273 static int trusted_tee_init(void)
275 return driver_register(&trusted_key_driver.driver);
278 static void trusted_tee_exit(void)
280 driver_unregister(&trusted_key_driver.driver);
283 struct trusted_key_ops trusted_key_tee_ops = {
284 .migratable = 0, /* non-migratable */
285 .init = trusted_tee_init,
286 .seal = trusted_tee_seal,
287 .unseal = trusted_tee_unseal,
288 .get_random = trusted_tee_get_random,
289 .exit = trusted_tee_exit,