FBE: add aml_trusted_key for kernel 5.15 [1/1]

PD#SWPL-130061

Problem:
Need to poring FBE from kernel 5.4 to 5.15

Solution:
1. Poring FBE from kernel 5.4 to 5.15
2. Use allocate shm as a workaround, since register shm
sometimes fails.

Verify:
1. SC2 + ah212 + RDK kernel 5.15

Change-Id: I69b2723bafca0cbe8cc9e26010a20dc33860fc54
Signed-off-by: Mingyen Hung <mingyen.hung@amlogic.com>

drivers/Kconfig

@@ -59,4 +59,5 @@ source "$(COMMON_DRIVERS_DIR)/drivers/algorithm/Kconfig"
 source "$(COMMON_DRIVERS_DIR)/drivers/firmware/Kconfig"
 source "$(COMMON_DRIVERS_DIR)/drivers/timestamp/Kconfig"
 source "$(COMMON_DRIVERS_DIR)/drivers/seckey/Kconfig"
+source "$(COMMON_DRIVERS_DIR)/drivers/aml_trusted_keys/Kconfig"
 endmenu

drivers/Makefile

@@ -20,6 +20,7 @@ obj-$(CONFIG_SPI)			+= spi/
 obj-y					+= char/
 obj-$(CONFIG_AMLOGIC_TEE)		+= tee/
 obj-$(CONFIG_AML_TEE)			+= aml_tee/
+obj-$(CONFIG_AMLOGIC_TRUSTED_KEYS)	+= aml_trusted_keys/
 obj-$(CONFIG_AMLOGIC_GX_SUSPEND)	+= pm/
 obj-$(CONFIG_INPUT)			+= input/
 obj-$(CONFIG_WATCHDOG)			+= watchdog/

drivers/aml_trusted_keys/Kconfig

@@ -0,0 +1,35 @@
+
+config AMLOGIC_LINUX_FBE
+	bool "Amlogic's FBE implementation"
+	default n
+	depends on AMLOGIC_TRUSTED_KEYS && AMLOGIC_TRUSTED_KEYS_TEE
+	help
+	  This option is for enabling Amlogic's FBE feature. Currently,
+	  it only works on trusted-key with tee backend.
+
+config AMLOGIC_LINUX_FBE_RDK
+	bool "Customization of Amlogic's FBE for RDK"
+	depends on AMLOGIC_LINUX_FBE
+	default n
+	help
+	  This option is for enabling customization of Amlogic's FBE for RDK
+
+config AMLOGIC_TRUSTED_KEYS
+	tristate "AMLOGIC TRUSTED_KEYS"
+	depends on KEYS
+	default n
+	help
+	  This option provides support for creating, sealing, and unsealing
+	  keys in the kernel. Trusted keys are random number symmetric keys,
+	  generated and sealed by a trust source selected at kernel boot-time.
+	  Userspace will only ever see encrypted blobs.
+
+	  If you are unsure as to whether this is required, answer N.
+
+config AMLOGIC_TRUSTED_KEYS_TEE
+	tristate "Amlogic TEE-based trusted keys"
+	depends on AML_TEE >= AMLOGIC_TRUSTED_KEYS
+	default n
+	help
+	  Enable use of the Trusted Execution Environment (TEE) as trusted
+	  key backend.

drivers/aml_trusted_keys/Makefile

@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+MODULE_NAME = amlogic-trusted-keys
+obj-$(CONFIG_AMLOGIC_TRUSTED_KEYS) = $(MODULE_NAME).o
+$(MODULE_NAME)-y += trusted_core.o
+$(MODULE_NAME)-$(CONFIG_AMLOGIC_TRUSTED_KEYS_TEE) += trusted_tee.o
+
+PR_FMT = $(subst amlogic-,,$(MODULE_NAME))
+PR_FMT_DEFINE="-Dpr_fmt(fmt)= \"[$(PR_FMT)]: \" fmt"
+ccflags-y += $(PR_FMT_DEFINE)
+BUILD_TIME := $(shell date +%Y.%m.%d-%H.%M.%S)
+ccflags-y += "-DBUILD_TIME=\"$(BUILD_TIME)\""
+
+COMMON_DRIVER_RELEASE=$(subst -g,, $(shell $(srctree)/scripts/setlocalversion $(srctree)/$(COMMON_DRIVERS_DIR)))
+COMMON_DRIVER_RELEASE_DEFINE="-DCOMMON_DRIVER_RELEASE=\"$(COMMON_DRIVER_RELEASE)\""
+ccflags-y += $(COMMON_DRIVER_RELEASE_DEFINE)

drivers/aml_trusted_keys/trusted_core.c

@@ -0,0 +1,402 @@
+// 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>
+#if IS_REACHABLE(CONFIG_AMLOGIC_TRUSTED_KEYS_TEE)
+#include <keys/trusted_tee.h>
+#endif
+#if IS_REACHABLE(CONFIG_TRUSTED_KEYS_CAAM)
+#include <keys/trusted_caam.h>
+#endif
+#if IS_REACHABLE(CONFIG_TRUSTED_KEYS_TPM)
+#include <keys/trusted_tpm.h>
+#endif
+#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/random.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_rng = "default";
+module_param_named(rng, trusted_rng, charp, 0);
+MODULE_PARM_DESC(rng, "Select trusted key RNG");
+
+static char *trusted_key_source;
+module_param_named(source, trusted_key_source, charp, 0);
+MODULE_PARM_DESC(source, "Select trusted keys source (tpm, tee or caam)");
+
+static const struct trusted_key_source trusted_key_sources[] = {
+#if IS_REACHABLE(CONFIG_AMLOGIC_TRUSTED_KEYS_TEE)
+	{ "tee", &trusted_key_tee_ops },
+#endif
+};
+
+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)
+		goto err;
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	if (!p)
+		goto err;
+
+	p->migratable = migratable;
+err:
+	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, *orig_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);
+	orig_datablob = datablob;
+	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(orig_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, *orig_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);
+	orig_datablob = datablob;
+	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(orig_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 kernel_get_random(unsigned char *key, size_t key_len)
+{
+	return get_random_bytes_wait(key, key_len) ?: key_len;
+}
+
+static int __init init_trusted(void)
+{
+	int (*get_random)(unsigned char *key, size_t key_len);
+	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;
+
+		/*
+		 * We always support trusted.rng="kernel" and "default" as
+		 * well as trusted.rng=$trusted.source if the trust source
+		 * defines its own get_random callback.
+		 */
+		get_random = trusted_key_sources[i].ops->get_random;
+		if (trusted_rng && strcmp(trusted_rng, "default")) {
+			if (!strcmp(trusted_rng, "kernel")) {
+				get_random = kernel_get_random;
+			} else if (strcmp(trusted_rng, trusted_key_sources[i].name) ||
+				   !get_random) {
+				if (get_random)
+					pr_warn("Unsupported RNG. Supported: kernel, %s, default\n",
+						trusted_key_sources[i].name);
+				else
+					pr_warn("Unsupported RNG. Supported: kernel, default\n");
+				return -EINVAL;
+			}
+		}
+
+		if (!get_random)
+			get_random = kernel_get_random;
+
+		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,
+				   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_cond(trusted_key_exit)();
+}
+
+late_initcall(init_trusted);
+module_exit(cleanup_trusted);
+
+MODULE_LICENSE("GPL");

drivers/aml_trusted_keys/trusted_tee.c

@@ -0,0 +1,432 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019-2021 Linaro Ltd.
+ *
+ * Author:
+ * Sumit Garg <sumit.garg@linaro.org>
+ */
+
+#include <linux/err.h>
+#include <linux/key-type.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/amlogic/tee_drv.h>
+#include <linux/uuid.h>
+
+#include <keys/trusted_tee.h>
+
+#define DRIVER_NAME "aml-trusted-key-tee"
+
+/*
+ * Get random data for symmetric key
+ *
+ * [out]     memref[0]        Random data
+ */
+#define TA_CMD_GET_RANDOM	0x0
+
+/*
+ * Seal trusted key using hardware unique key
+ *
+ * [in]      memref[0]        Plain key
+ * [out]     memref[1]        Sealed key datablob
+ */
+#define TA_CMD_SEAL		0x1
+
+/*
+ * Unseal trusted key using hardware unique key
+ *
+ * [in]      memref[0]        Sealed key datablob
+ * [out]     memref[1]        Plain key
+ */
+#define TA_CMD_UNSEAL		0x2
+#define MAX_EXTRA_SIZE      (512)
+/**
+ * struct trusted_key_tee_private - TEE Trusted key private data
+ * @dev:		TEE based Trusted key device.
+ * @ctx:		TEE context handler.
+ * @session_id:		Trusted key TA session identifier.
+ * @shm_pool:		Memory pool shared with TEE device.
+ */
+struct trusted_key_tee_private {
+	struct device *dev;
+	struct tee_context *ctx;
+	u32 session_id;
+	struct tee_shm *shm_pool;
+};
+
+static struct trusted_key_tee_private pvt_data;
+#define USE_SHM_ALLOC	(1)
+/*
+ * Have the TEE seal(encrypt) the symmetric key
+ */
+static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
+{
+	int ret;
+	struct tee_ioctl_invoke_arg inv_arg;
+	struct tee_param param[4];
+	struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL;
+#if IS_ENABLED(CONFIG_AMLOGIC_LINUX_FBE_RDK)
+	struct tee_shm *reg_shm_extra_in = NULL;
+	u8 extra[MAX_EXTRA_SIZE];
+	u32 extra_sz = 0;
+#endif
+	memset(&inv_arg, 0, sizeof(inv_arg));
+	memset(&param, 0, sizeof(param));
+#if IS_ENABLED(CONFIG_AMLOGIC_LINUX_FBE_RDK)
+	memset(extra, 0, sizeof(extra));
+#endif
+
+#if USE_SHM_ALLOC
+	reg_shm_in = tee_shm_alloc_kernel_buf(pvt_data.ctx, p->key_len);
+	if (IS_ERR(reg_shm_in)) {
+		dev_err(pvt_data.dev, "key shm alloc failed\n");
+		return PTR_ERR(reg_shm_in);
+	}
+	memcpy(reg_shm_in->kaddr, p->key, p->key_len);
+	reg_shm_out = tee_shm_alloc_kernel_buf(pvt_data.ctx, sizeof(p->blob));
+	if (IS_ERR(reg_shm_out)) {
+		dev_err(pvt_data.dev, "blob shm register failed\n");
+		ret = PTR_ERR(reg_shm_out);
+		goto out;
+	}
+#else
+	reg_shm_in = tee_shm_register_kernel_buf(pvt_data.ctx, p->key,
+						 p->key_len);
+	if (IS_ERR(reg_shm_in)) {
+		dev_err(pvt_data.dev, "key shm register failed\n");
+		return PTR_ERR(reg_shm_in);
+	}
+	reg_shm_out = tee_shm_register_kernel_buf(pvt_data.ctx, p->blob,
+						  sizeof(p->blob));
+	if (IS_ERR(reg_shm_out)) {
+		dev_err(pvt_data.dev, "blob shm register failed\n");
+		ret = PTR_ERR(reg_shm_out);
+		goto out;
+	}
+#endif
+#if IS_ENABLED(CONFIG_AMLOGIC_LINUX_FBE_RDK)
+	/* set uid as extra */
+	if (sizeof(extra) >= sizeof(uid_t)) {
+		memcpy(extra, &(current_uid().val), sizeof(uid_t));
+		extra_sz += sizeof(uid_t);
+	} else {
+		dev_err(pvt_data.dev, "extra buf is too small\n");
+	}
+#if USE_SHM_ALLOC
+	reg_shm_extra_in = tee_shm_alloc_kernel_buf(pvt_data.ctx, extra_sz);
+	if (IS_ERR(reg_shm_extra_in)) {
+		dev_err(pvt_data.dev, "extra shm register failed\n");
+		ret = PTR_ERR(reg_shm_extra_in);
+		goto out;
+	}
+	memcpy(reg_shm_extra_in->kaddr, extra, extra_sz);
+#else
+	reg_shm_extra_in = tee_shm_register_kernel_buf(pvt_data.ctx, extra,
+						 extra_sz);
+	if (IS_ERR(reg_shm_extra_in)) {
+		dev_err(pvt_data.dev, "extra shm register failed\n");
+		ret = PTR_ERR(reg_shm_extra_in);
+		goto out;
+	}
+#endif
+#endif
+	inv_arg.func = TA_CMD_SEAL;
+	inv_arg.session = pvt_data.session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+	param[0].u.memref.shm = reg_shm_in;
+	param[0].u.memref.size = p->key_len;
+	param[0].u.memref.shm_offs = 0;
+	param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[1].u.memref.shm = reg_shm_out;
+	param[1].u.memref.size = sizeof(p->blob);
+	param[1].u.memref.shm_offs = 0;
+#if IS_ENABLED(CONFIG_AMLOGIC_LINUX_FBE_RDK)
+	param[2].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+	param[2].u.memref.shm = reg_shm_extra_in;
+	param[2].u.memref.size = extra_sz;
+	param[2].u.memref.shm_offs = 0;
+#endif
+	ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0) {
+		dev_err(pvt_data.dev, "TA_CMD_SEAL invoke err: %x\n",
+			inv_arg.ret);
+		ret = -EFAULT;
+	} else {
+		p->blob_len = param[1].u.memref.size;
+#if USE_SHM_ALLOC
+		memcpy(p->blob, reg_shm_out->kaddr, p->blob_len);
+#endif
+	}
+
+out:
+	if (reg_shm_out)
+		tee_shm_free(reg_shm_out);
+	if (reg_shm_in)
+		tee_shm_free(reg_shm_in);
+#if IS_ENABLED(CONFIG_AMLOGIC_LINUX_FBE_RDK)
+	if (reg_shm_extra_in)
+		tee_shm_free(reg_shm_extra_in);
+#endif
+	return ret;
+}
+
+/*
+ * Have the TEE unseal(decrypt) the symmetric key
+ */
+static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
+{
+	int ret;
+	struct tee_ioctl_invoke_arg inv_arg;
+	struct tee_param param[4];
+	struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL;
+#if IS_ENABLED(CONFIG_AMLOGIC_LINUX_FBE_RDK)
+	struct tee_shm *reg_shm_extra_in = NULL;
+	u8 extra[MAX_EXTRA_SIZE];
+	u32 extra_sz = 0;
+#endif
+	memset(&inv_arg, 0, sizeof(inv_arg));
+	memset(&param, 0, sizeof(param));
+#if IS_ENABLED(CONFIG_AMLOGIC_LINUX_FBE_RDK)
+	memset(extra, 0, sizeof(extra));
+#endif
+#if USE_SHM_ALLOC
+	reg_shm_in = tee_shm_alloc_kernel_buf(pvt_data.ctx, p->blob_len);
+	if (IS_ERR(reg_shm_in)) {
+		dev_err(pvt_data.dev, "blob shm register failed\n");
+		return PTR_ERR(reg_shm_in);
+	}
+	memcpy(reg_shm_in->kaddr, p->blob, p->blob_len);
+	reg_shm_out = tee_shm_alloc_kernel_buf(pvt_data.ctx, sizeof(p->key));
+	if (IS_ERR(reg_shm_out)) {
+		dev_err(pvt_data.dev, "key shm register failed\n");
+		ret = PTR_ERR(reg_shm_out);
+		goto out;
+	}
+#else
+	reg_shm_in = tee_shm_register_kernel_buf(pvt_data.ctx, p->blob,
+						 p->blob_len);
+	if (IS_ERR(reg_shm_in)) {
+		dev_err(pvt_data.dev, "blob shm register failed\n");
+		return PTR_ERR(reg_shm_in);
+	}
+	reg_shm_out = tee_shm_register_kernel_buf(pvt_data.ctx, p->key,
+						  sizeof(p->key));
+	if (IS_ERR(reg_shm_out)) {
+		dev_err(pvt_data.dev, "key shm register failed\n");
+		ret = PTR_ERR(reg_shm_out);
+		goto out;
+	}
+#endif
+#if IS_ENABLED(CONFIG_AMLOGIC_LINUX_FBE_RDK)
+	if (sizeof(extra) >= sizeof(uid_t)) {
+		memcpy(extra, &(current_uid().val), sizeof(uid_t));
+		extra_sz += sizeof(uid_t);
+	} else {
+		dev_err(pvt_data.dev, "extra buf is too small\n");
+	}
+#if USE_SHM_ALLOC
+	reg_shm_extra_in = tee_shm_alloc_kernel_buf(pvt_data.ctx, extra_sz);
+	if (IS_ERR(reg_shm_extra_in)) {
+		dev_err(pvt_data.dev, "extra shm register failed\n");
+		return PTR_ERR(reg_shm_extra_in);
+	}
+	memcpy(reg_shm_extra_in->kaddr, extra, extra_sz);
+#else
+	reg_shm_extra_in = tee_shm_register_kernel_buf(pvt_data.ctx, extra,
+						 sizeof(extra));
+	if (IS_ERR(reg_shm_extra_in)) {
+		dev_err(pvt_data.dev, "extra shm register failed\n");
+		return PTR_ERR(reg_shm_extra_in);
+	}
+#endif
+#endif
+	inv_arg.func = TA_CMD_UNSEAL;
+	inv_arg.session = pvt_data.session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+	param[0].u.memref.shm = reg_shm_in;
+	param[0].u.memref.size = p->blob_len;
+	param[0].u.memref.shm_offs = 0;
+	param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[1].u.memref.shm = reg_shm_out;
+	param[1].u.memref.size = sizeof(p->key);
+	param[1].u.memref.shm_offs = 0;
+#if IS_ENABLED(CONFIG_AMLOGIC_LINUX_FBE_RDK)
+	param[2].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+	param[2].u.memref.shm = reg_shm_extra_in;
+	param[2].u.memref.size = extra_sz;
+	param[2].u.memref.shm_offs = 0;
+#endif
+	ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0) {
+		dev_err(pvt_data.dev, "TA_CMD_UNSEAL invoke err: %x\n",
+			inv_arg.ret);
+		ret = -EFAULT;
+	} else {
+		p->key_len = param[1].u.memref.size;
+#if USE_SHM_ALLOC
+		memcpy(p->key, reg_shm_out->kaddr, p->key_len);
+#endif
+	}
+
+out:
+	if (reg_shm_out)
+		tee_shm_free(reg_shm_out);
+	if (reg_shm_in)
+		tee_shm_free(reg_shm_in);
+#if IS_ENABLED(CONFIG_AMLOGIC_LINUX_FBE_RDK)
+	if (reg_shm_extra_in)
+		tee_shm_free(reg_shm_extra_in);
+#endif
+	return ret;
+}
+
+/*
+ * Have the TEE generate random symmetric key
+ */
+static int trusted_tee_get_random(unsigned char *key, size_t key_len)
+{
+	int ret;
+	struct tee_ioctl_invoke_arg inv_arg;
+	struct tee_param param[4];
+	struct tee_shm *reg_shm = NULL;
+
+	memset(&inv_arg, 0, sizeof(inv_arg));
+	memset(&param, 0, sizeof(param));
+
+#if USE_SHM_ALLOC
+	//dev_err(pvt_data.dev, " USE_SHM_ALLOC\n");
+	reg_shm = tee_shm_alloc_kernel_buf(pvt_data.ctx, key_len);
+#else
+	//dev_err(pvt_data.dev, " USE_SHM_REG\n");
+	reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, key, key_len);
+#endif
+	if (IS_ERR(reg_shm)) {
+		dev_err(pvt_data.dev, "key shm register failed\n");
+		return PTR_ERR(reg_shm);
+	}
+
+	inv_arg.func = TA_CMD_GET_RANDOM;
+	inv_arg.session = pvt_data.session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[0].u.memref.shm = reg_shm;
+	param[0].u.memref.size = key_len;
+	param[0].u.memref.shm_offs = 0;
+
+	ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0) {
+		dev_err(pvt_data.dev, "TA_CMD_GET_RANDOM invoke err: %x, %x\n",
+			inv_arg.ret, inv_arg.ret_origin);
+		ret = -EFAULT;
+	} else {
+		ret = param[0].u.memref.size;
+#if USE_SHM_ALLOC
+		memcpy(key, reg_shm->kaddr, key_len);
+#endif
+	}
+
+	tee_shm_free(reg_shm);
+
+	return ret;
+}
+
+static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
+{
+	if (ver->impl_id == TEE_IMPL_ID_OPTEE)
+		return 1;
+	else
+		return 0;
+}
+
+static int trusted_key_probe(struct device *dev)
+{
+	struct tee_client_device *rng_device = to_tee_client_device(dev);
+	int ret;
+	struct tee_ioctl_open_session_arg sess_arg;
+
+	memset(&sess_arg, 0, sizeof(sess_arg));
+
+	pvt_data.ctx = tee_client_open_context(NULL, optee_ctx_match, NULL,
+					       NULL);
+	if (IS_ERR(pvt_data.ctx))
+		return -ENODEV;
+
+	memcpy(sess_arg.uuid, rng_device->id.uuid.b, TEE_IOCTL_UUID_LEN);
+	sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
+	sess_arg.num_params = 0;
+
+	ret = tee_client_open_session(pvt_data.ctx, &sess_arg, NULL);
+	if (ret < 0 || sess_arg.ret != 0) {
+		dev_err(dev, "tee_client_open_session failed, err: %x\n",
+			sess_arg.ret);
+		ret = -EINVAL;
+		goto out_ctx;
+	}
+	pvt_data.session_id = sess_arg.session;
+
+	ret = register_key_type(&key_type_trusted);
+	if (ret < 0)
+		goto out_sess;
+
+	pvt_data.dev = dev;
+
+	return 0;
+
+out_sess:
+	tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
+out_ctx:
+	tee_client_close_context(pvt_data.ctx);
+
+	return ret;
+}
+
+static int trusted_key_remove(struct device *dev)
+{
+	unregister_key_type(&key_type_trusted);
+	tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
+	tee_client_close_context(pvt_data.ctx);
+
+	return 0;
+}
+
+static const struct tee_client_device_id trusted_key_id_table[] = {
+	{UUID_INIT(0xf04a0fe7, 0x1f5d, 0x4b9b,
+		   0xab, 0xf7, 0x61, 0x9b, 0x85, 0xb4, 0xce, 0x8c)},
+	{}
+};
+MODULE_DEVICE_TABLE(tee, trusted_key_id_table);
+
+static struct tee_client_driver trusted_key_driver = {
+	.id_table	= trusted_key_id_table,
+	.driver		= {
+		.name		= DRIVER_NAME,
+		.bus		= &tee_bus_type,
+		.probe		= trusted_key_probe,
+		.remove		= trusted_key_remove,
+	},
+};
+
+static int trusted_tee_init(void)
+{
+	return driver_register(&trusted_key_driver.driver);
+}
+
+static void trusted_tee_exit(void)
+{
+	driver_unregister(&trusted_key_driver.driver);
+}
+
+struct trusted_key_ops trusted_key_tee_ops = {
+	.migratable = 0, /* non-migratable */
+	.init = trusted_tee_init,
+	.seal = trusted_tee_seal,
+	.unseal = trusted_tee_unseal,
+	.get_random = trusted_tee_get_random,
+	.exit = trusted_tee_exit,
+};