security/keys/trusted-keys/trusted_tee.c - linux - Git at Google

 // 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/tee_drv.h>
 #include <linux/uuid.h>

 #include <keys/trusted_tee.h>

 #define DRIVER_NAME "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

 /**
  * 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;

 /*
  * 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 = NULL;

 	memset(&inv_arg, 0, sizeof(inv_arg));
 	memset(&param, 0, sizeof(param));

 	reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, p->key,
 					      sizeof(p->key) + sizeof(p->blob));
 	if (IS_ERR(reg_shm)) {
 		dev_err(pvt_data.dev, "shm register failed\n");
 		return PTR_ERR(reg_shm);
 	}

 	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;
 	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;
 	param[1].u.memref.size = sizeof(p->blob);
 	param[1].u.memref.shm_offs = sizeof(p->key);

 	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;
 	}

 	tee_shm_free(reg_shm);

 	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 = NULL;

 	memset(&inv_arg, 0, sizeof(inv_arg));
 	memset(&param, 0, sizeof(param));

 	reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, p->key,
 					      sizeof(p->key) + sizeof(p->blob));
 	if (IS_ERR(reg_shm)) {
 		dev_err(pvt_data.dev, "shm register failed\n");
 		return PTR_ERR(reg_shm);
 	}

 	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;
 	param[0].u.memref.size = p->blob_len;
 	param[0].u.memref.shm_offs = sizeof(p->key);
 	param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
 	param[1].u.memref.shm = reg_shm;
 	param[1].u.memref.size = sizeof(p->key);
 	param[1].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_UNSEAL invoke err: %x\n",
 			inv_arg.ret);
 		ret = -EFAULT;
 	} else {
 		p->key_len = param[1].u.memref.size;
 	}

 	tee_shm_free(reg_shm);

 	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));

 	reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, key, key_len);
 	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\n",
 			inv_arg.ret);
 		ret = -EFAULT;
 	} else {
 		ret = param[0].u.memref.size;
 	}

 	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 &&
 	    ver->gen_caps & TEE_GEN_CAP_REG_MEM)
 		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,
 };
	// 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/tee_drv.h>
	#include <linux/uuid.h>

	#include <keys/trusted_tee.h>

	#define DRIVER_NAME "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

	/**
	* 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;

	/*
	* 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 = NULL;

	memset(&inv_arg, 0, sizeof(inv_arg));
	memset(&param, 0, sizeof(param));

	reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, p->key,
	sizeof(p->key) + sizeof(p->blob));
	if (IS_ERR(reg_shm)) {
	dev_err(pvt_data.dev, "shm register failed\n");
	return PTR_ERR(reg_shm);
	}

	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;
	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;
	param[1].u.memref.size = sizeof(p->blob);
	param[1].u.memref.shm_offs = sizeof(p->key);

	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;
	}

	tee_shm_free(reg_shm);

	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 = NULL;

	memset(&inv_arg, 0, sizeof(inv_arg));
	memset(&param, 0, sizeof(param));

	reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, p->key,
	sizeof(p->key) + sizeof(p->blob));
	if (IS_ERR(reg_shm)) {
	dev_err(pvt_data.dev, "shm register failed\n");
	return PTR_ERR(reg_shm);
	}

	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;
	param[0].u.memref.size = p->blob_len;
	param[0].u.memref.shm_offs = sizeof(p->key);
	param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
	param[1].u.memref.shm = reg_shm;
	param[1].u.memref.size = sizeof(p->key);
	param[1].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_UNSEAL invoke err: %x\n",
	inv_arg.ret);
	ret = -EFAULT;
	} else {
	p->key_len = param[1].u.memref.size;
	}

	tee_shm_free(reg_shm);

	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));

	reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, key, key_len);
	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\n",
	inv_arg.ret);
	ret = -EFAULT;
	} else {
	ret = param[0].u.memref.size;
	}

	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 &&
	ver->gen_caps & TEE_GEN_CAP_REG_MEM)
	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,
	};