Raw access to trusted application secure storage

This change provides basics for creating, reading and deleting an
object in a TA secure storage.

The TA implementation shows how to use the GPD TEE Internal Core API
for some basic data persistent object manipulations.

A TA command allows to create an object in the TA secure storage.
A TA command allows to read an object in the TA secure storage.
A TA command allows to delete an object from the TA secure storage.

This example does not cover all the possibilities of secure storage API
provided to TAs: seeking into a object data stream, manipulating
key material objects instead of raw data objects, etc.

Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Acked-by: Jerome Forissier <jerome.forissier@linaro.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

.gitignore

@@ -17,3 +17,4 @@ hello_world/host/optee_example_hello_world
 random/host/optee_example_random
 aes/host/optee_example_aes
 hotp/host/optee_example_hotp
+secure_storage/host/optee_example_secure_storage

README.md

@@ -33,6 +33,12 @@ ciphered data.
 * Test application: `optee_example_aes`
 * Trusted application UUID: 5dbac793-f574-4871-8ad3-04331ec17f24
 
+Directory **secure_storage/**:
+* A Trusted Application to read/write raw data into the
+OP-TEE secure storage using the GPD TEE Internal Core API.
+* Test application: `optee_example_secure_storage`
+* Trusted application UUID: f4e750bb-1437-4fbf-8785-8d3580c34994
+
 ## 3. How to build a Trusted Application
 [TA basics] documentation presents the basics for  implementing and building
 an OP-TEE trusted application.

secure_storage/Android.mk

@@ -0,0 +1,19 @@
+LOCAL_PATH := $(call my-dir)
+
+OPTEE_CLIENT_EXPORT ?= $(LOCAL_PATH)/../../optee_client/out/export
+
+include $(CLEAR_VARS)
+LOCAL_CFLAGS += -DANDROID_BUILD
+LOCAL_CFLAGS += -Wall
+
+LOCAL_SRC_FILES += host/main.c
+
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/ta/include \
+		    $(OPTEE_CLIENT_EXPORT)/include
+
+LOCAL_SHARED_LIBRARIES := libteec
+LOCAL_MODULE := optee_example_secure_storage
+LOCAL_MODULE_TAGS := optional
+include $(BUILD_EXECUTABLE)
+
+include $(LOCAL_PATH)/ta/Android.mk

secure_storage/Makefile

@@ -0,0 +1,15 @@
+export V ?= 0
+
+# If _HOST or _TA specific compilers are not specified, then use CROSS_COMPILE
+HOST_CROSS_COMPILE ?= $(CROSS_COMPILE)
+TA_CROSS_COMPILE ?= $(CROSS_COMPILE)
+
+.PHONY: all
+all:
+	$(MAKE) -C host CROSS_COMPILE="$(HOST_CROSS_COMPILE)"
+	$(MAKE) -C ta CROSS_COMPILE="$(TA_CROSS_COMPILE)"
+
+.PHONY: clean
+clean:
+	$(MAKE) -C host clean
+	$(MAKE) -C ta clean

secure_storage/host/Makefile

@@ -0,0 +1,25 @@
+CC      = $(CROSS_COMPILE)gcc
+LD      = $(CROSS_COMPILE)ld
+AR      = $(CROSS_COMPILE)ar
+NM      = $(CROSS_COMPILE)nm
+OBJCOPY = $(CROSS_COMPILE)objcopy
+OBJDUMP = $(CROSS_COMPILE)objdump
+READELF = $(CROSS_COMPILE)readelf
+
+OBJS = main.o
+
+CFLAGS += -Wall -I../ta/include -I./include
+CFLAGS += -I$(TEEC_EXPORT)/include
+LDADD += -lteec -L$(TEEC_EXPORT)/lib
+
+BINARY = optee_example_secure_storage
+
+.PHONY: all
+all: $(BINARY)
+
+$(BINARY): $(OBJS)
+	$(CC) -o $@ $< $(LDADD)
+
+.PHONY: clean
+clean:
+	rm -f $(OBJS) $(BINARY)

secure_storage/host/main.c

@@ -0,0 +1,241 @@
+/*
+ * Copyright (c) 2017, Linaro Limited
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <err.h>
+#include <stdio.h>
+#include <string.h>
+
+/* OP-TEE TEE client API (built by optee_client) */
+#include <tee_client_api.h>
+
+/* TA API: UUID and command IDs */
+#include <secure_storage_ta.h>
+
+/* TEE resources */
+struct test_ctx {
+	TEEC_Context ctx;
+	TEEC_Session sess;
+};
+
+void prepare_tee_session(struct test_ctx *ctx)
+{
+	TEEC_UUID uuid = TA_SECURE_STORAGE_UUID;
+	uint32_t origin;
+	TEEC_Result res;
+
+	/* Initialize a context connecting us to the TEE */
+	res = TEEC_InitializeContext(NULL, &ctx->ctx);
+	if (res != TEEC_SUCCESS)
+		errx(1, "TEEC_InitializeContext failed with code 0x%x", res);
+
+	/* Open a session with the TA */
+	res = TEEC_OpenSession(&ctx->ctx, &ctx->sess, &uuid,
+			       TEEC_LOGIN_PUBLIC, NULL, NULL, &origin);
+	if (res != TEEC_SUCCESS)
+		errx(1, "TEEC_Opensession failed with code 0x%x origin 0x%x",
+			res, origin);
+}
+
+void terminate_tee_session(struct test_ctx *ctx)
+{
+	TEEC_CloseSession(&ctx->sess);
+	TEEC_FinalizeContext(&ctx->ctx);
+}
+
+TEEC_Result read_secure_object(struct test_ctx *ctx, char *id,
+			char *data, size_t data_len)
+{
+	TEEC_Operation op;
+	uint32_t origin;
+	TEEC_Result res;
+	size_t id_len = strlen(id);
+
+	memset(&op, 0, sizeof(op));
+	op.paramTypes = TEEC_PARAM_TYPES(TEEC_MEMREF_TEMP_INPUT,
+					 TEEC_MEMREF_TEMP_OUTPUT,
+					 TEEC_NONE, TEEC_NONE);
+
+	op.params[0].tmpref.buffer = id;
+	op.params[0].tmpref.size = id_len;
+
+	op.params[1].tmpref.buffer = data;
+	op.params[1].tmpref.size = data_len;
+
+	res = TEEC_InvokeCommand(&ctx->sess,
+				 TA_SECURE_STORAGE_CMD_READ_RAW,
+				 &op, &origin);
+	switch (res) {
+	case TEEC_SUCCESS:
+	case TEEC_ERROR_SHORT_BUFFER:
+	case TEEC_ERROR_ITEM_NOT_FOUND:
+		break;
+	default:
+		printf("Command READ_RAW failed: 0x%x / %u\n", res, origin);
+	}
+
+	return res;
+}
+
+TEEC_Result write_secure_object(struct test_ctx *ctx, char *id,
+			char *data, size_t data_len)
+{
+	TEEC_Operation op;
+	uint32_t origin;
+	TEEC_Result res;
+	size_t id_len = strlen(id);
+
+	memset(&op, 0, sizeof(op));
+	op.paramTypes = TEEC_PARAM_TYPES(TEEC_MEMREF_TEMP_INPUT,
+					 TEEC_MEMREF_TEMP_INPUT,
+					 TEEC_NONE, TEEC_NONE);
+
+	op.params[0].tmpref.buffer = id;
+	op.params[0].tmpref.size = id_len;
+
+	op.params[1].tmpref.buffer = data;
+	op.params[1].tmpref.size = data_len;
+
+	res = TEEC_InvokeCommand(&ctx->sess,
+				 TA_SECURE_STORAGE_CMD_WRITE_RAW,
+				 &op, &origin);
+	if (res != TEEC_SUCCESS)
+		printf("Command WRITE_RAW failed: 0x%x / %u\n", res, origin);
+
+	switch (res) {
+	case TEEC_SUCCESS:
+		break;
+	default:
+		printf("Command WRITE_RAW failed: 0x%x / %u\n", res, origin);
+	}
+
+	return res;
+}
+
+TEEC_Result delete_secure_object(struct test_ctx *ctx, char *id)
+{
+	TEEC_Operation op;
+	uint32_t origin;
+	TEEC_Result res;
+	size_t id_len = strlen(id);
+
+	memset(&op, 0, sizeof(op));
+	op.paramTypes = TEEC_PARAM_TYPES(TEEC_MEMREF_TEMP_INPUT,
+					 TEEC_NONE, TEEC_NONE, TEEC_NONE);
+
+	op.params[0].tmpref.buffer = id;
+	op.params[0].tmpref.size = id_len;
+
+	res = TEEC_InvokeCommand(&ctx->sess,
+				 TA_SECURE_STORAGE_CMD_DELETE,
+				 &op, &origin);
+
+	switch (res) {
+	case TEEC_SUCCESS:
+	case TEEC_ERROR_ITEM_NOT_FOUND:
+		break;
+	default:
+		printf("Command DELETE failed: 0x%x / %u\n", res, origin);
+	}
+
+	return res;
+}
+
+#define TEST_OBJECT_SIZE	7000
+
+int main(int argc, char *argv[])
+{
+	struct test_ctx ctx;
+	char obj1_id[] = "object#1";		/* string identification for the object */
+	char obj2_id[] = "object#2";		/* string identification for the object */
+	char obj1_data[TEST_OBJECT_SIZE];
+	char read_data[TEST_OBJECT_SIZE];
+	TEEC_Result res;
+
+	printf("Prepare session with the TA\n");
+	prepare_tee_session(&ctx);
+
+	/*
+	 * Create object, read it, delete it.
+	 */
+	printf("\nTest on object \"%s\"\n", obj1_id);
+
+	printf("- Create and load object in the TA secure storage\n");
+
+	memset(obj1_data, 0xA1, sizeof(obj1_data));
+
+	res = write_secure_object(&ctx, obj1_id,
+				  obj1_data, sizeof(obj1_data));
+	if (res != TEEC_SUCCESS)
+		errx(1, "Failed to create an object in the secure storage");
+
+	printf("- Read back the object\n");
+
+	res = read_secure_object(&ctx, obj1_id,
+				 read_data, sizeof(read_data));
+	if (res != TEEC_SUCCESS)
+		errx(1, "Failed to read an object from the secure storage");
+	if (memcmp(obj1_data, read_data, sizeof(obj1_data)))
+		errx(1, "Unexpected content found in secure storage");
+
+	printf("- Delete the object\n");
+
+	res = delete_secure_object(&ctx, obj1_id);
+	if (res != TEEC_SUCCESS)
+		errx(1, "Failed to delete the object: 0x%x", res);
+
+	/*
+	 * Non volatile storage: create object2 if not found, delete it if found
+	 */
+	printf("\nTest on object \"%s\"\n", obj2_id);
+
+	res = read_secure_object(&ctx, obj2_id,
+				  read_data, sizeof(read_data));
+	if (res != TEEC_SUCCESS && res != TEEC_ERROR_ITEM_NOT_FOUND)
+		errx(1, "Unexpected status when reading an object : 0x%x", res);
+
+	if (res == TEEC_ERROR_ITEM_NOT_FOUND) {
+		char data[] = "This is data stored in the secure storage.\n";
+
+		printf("- Object not found in TA secure storage, create it.\n");
+
+		res = write_secure_object(&ctx, obj2_id,
+					  data, sizeof(data));
+		if (res != TEEC_SUCCESS)
+			errx(1, "Failed to create/load an object");
+
+	} else if (res == TEEC_SUCCESS) {
+		printf("- Object found in TA secure storage, delete it.\n");
+
+		res = delete_secure_object(&ctx, obj2_id);
+		if (res != TEEC_SUCCESS)
+			errx(1, "Failed to delete an object");
+	}
+
+	printf("\nWe're done, close and release TEE resources\n");
+	terminate_tee_session(&ctx);
+	return 0;
+}

secure_storage/ta/Android.mk

@@ -0,0 +1,4 @@
+LOCAL_PATH := $(call my-dir)
+
+local_module := f4e750bb-1437-4fbf-8785-8d3580c34994.ta
+include $(BUILD_OPTEE_MK)

secure_storage/ta/Makefile

@@ -0,0 +1,13 @@
+CFG_TEE_TA_LOG_LEVEL ?= 2
+CPPFLAGS += -DCFG_TEE_TA_LOG_LEVEL=$(CFG_TEE_TA_LOG_LEVEL)
+
+# The UUID for the Trusted Application
+BINARY=f4e750bb-1437-4fbf-8785-8d3580c34994
+
+-include $(TA_DEV_KIT_DIR)/mk/ta_dev_kit.mk
+
+ifeq ($(wildcard $(TA_DEV_KIT_DIR)/mk/ta_dev_kit.mk), )
+clean:
+	@echo 'Note: $$(TA_DEV_KIT_DIR)/mk/ta_dev_kit.mk not found, cannot clean TA'
+	@echo 'Note: TA_DEV_KIT_DIR=$(TA_DEV_KIT_DIR)'
+endif