# secGear **Repository Path**: openeuler/secGear ## Basic Information - **Project Name**: secGear - **Description**: Confidential computing framework for developing enclave apps on top of hardware TEE - **Primary Language**: Unknown - **License**: Not specified - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 93 - **Forks**: 113 - **Created**: 2020-08-18 - **Last Updated**: 2025-12-10 ## Categories & Tags **Categories**: security-dev **Tags**: sig-confidential-computing ## README secGear secGear ============================ Introduction ----------- secGear is an SDK to develop confidential computing apps based on hardware enclave features. The target is to write single source code for apps running on different hardware. Currently secGear supports Intel SGX and iTrustee running in ARM Trustzone. Build and Install ---------------- - [reference build & install](./sdk/docs/build_install.md) Develope Application and Compile ------------------------------ Assuming the development directory is .../secGear/examples/test/ ### 1 Write edl interface description ```edl enclave { include "secgear_urts.h" from "secgear_tstdc.edl" import *; trusted { public int get_string([out, size=32]char *buf); }; }; ``` include "secgear_urts.h", from "secgear_tstdc.edl" import *, to shield the difference between SGX and iTrustee when calling the C library. So as long as the C library functions are used, for the consistency of the source code, the two files need be imported. For details about edl syntax, please refer to the SGX development document Enclave Definition Language Syntax section. At present, SGX and iTrustee are compatible with each other in basic types, pointer buffers, and deep copy of structures, but currently only SGX supports features like user_check, Granting Access to ECALLs, Using Switchless Calls and so on. Then save as test.edl ### 2 Write the top-level CMakeLists.txt ```cmake cmake_minimum_required(VERSION 3.10 FATAL_ERROR) project(TEST C) set(CMAKE_C_STANDARD 99) set(CURRENT_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR}) set(EDL_FILE test.edl) set(LOCAL_ROOT_PATH "$ENV{CC_SDK}") set(SECGEAR_INSTALL_PATH /usr/lib64/) set(CODEGEN codegen) if(CC_GP) set(CODETYPE trustzone) execute_process(COMMAND uuidgen -r OUTPUT_VARIABLE UUID) string(REPLACE "\n" "" UUID ${UUID}) add_definitions(-DPATH="/data/${UUID}.sec") endif() if(CC_SGX) set(CODETYPE sgx) add_definitions(-DPATH="${CMAKE_CURRENT_BINARY_DIR}/enclave/enclave.signed.so") endif() add_subdirectory(${CURRENT_ROOT_PATH}/enclave) add_subdirectory(${CURRENT_ROOT_PATH}/host) ``` Set the CODETYPE EDL_FILE and CODETYPE attributes, which are used when automatically generating code at later phase. On ARM platform, the enclave image needs be named with a unique UUID, so it is dynamically uniquely generated using the uuidgen command. The defined DPATH macro is used when loading the enclave image. ### 3 Write the non-secure side code and CMakeLists.txt #### 3.1 Create a new host directory and write main.c ```c #include #include "enclave.h" #include "test_u.h" #define BUF_LEN 32 int main() { int retval = 0; char *path = PATH; char buf[BUF_LEN]; cc_enclave_t *context = NULL; cc_enclave_result_t res; res = cc_enclave_create(path, AUTO_ENCLAVE_TYPE, 0, SECGEAR_DEBUG_FLAG, NULL, 0, &context); ... res = get_string(context, &retval, buf); if (res != CC_SUCCESS || retval != (int)CC_SUCCESS) { printf("Ecall enclave error\n"); } else { printf("%s\n", buf); } if (context != NULL) { res = cc_enclave_destroy(context); ... } return res; } ``` include "enclave.h", to import the secGear header file, include "test_u.h" to import the automatically generated code header file. Next, call cc_enclave_create(...) to create the enclave context, and then call the wrapper of the interface described in the edl file to enter the enclave to execute confidential code. Finally, call cc_enclave_destroy(...) to destroy the enclave context. Note that comparing to arguments defined in edl file, the interface called here has two more arguments, context and retval. This is because the function, generated by the automatic code generation tool according to edl, is a wrapper of the real enclave function, and its declaration is in the test_u.h header file. Where the context parameter is the cc_enclave_t * context created before calling the function, and retval is the return value of the function defined in edl, and the res argument is the return value of the wrapped function. The prefix of test_u.h is consistent with the prefix of test.edl. If the function defined in edl does not return a value, such as "public void get_string([out, size=32]char *buf);", the interface called by the user would be "res = get_string(context, buf);". According to these rules, code can be written before the wrapper function is generated by code generation tool in the compilation phase, which simplifies the development and compilation steps. #### 3.2 Write the CMakeLists.txt file of the host. ```cmake #set auto code prefix set(PREFIX test) #set host exec name set(OUTPUT secgear_test) #set host src code set(SOURCE_FILE ${CMAKE_CURRENT_SOURCE_DIR}/main.c) Set some variables, which are described in comments. #set auto code if(CC_GP) set(AUTO_FILES ${CMAKE_CURRENT_BINARY_DIR}/${PREFIX}_u.h ${CMAKE_CURRENT_BINARY_DIR}/${PREFIX}_u.c ${CMAKE_CURRENT_BINARY_DIR}/${PREFIX}_args.h) add_custom_command(OUTPUT ${AUTO_FILES} DEPENDS ${CURRENT_ROOT_PATH}/${EDL_FILE} COMMAND ${CODEGEN} --${CODETYPE} --untrusted ${CURRENT_ROOT_PATH}/${EDL_FILE} --search-path ${LOCAL_ROOT_PATH}/inc/host_inc/gp) endif() if(CC_SGX) set(AUTO_FILES ${CMAKE_CURRENT_BINARY_DIR}/${PREFIX}_u.h ${CMAKE_CURRENT_BINARY_DIR}/${PREFIX}_u.c) add_custom_command(OUTPUT ${AUTO_FILES} DEPENDS ${CURRENT_ROOT_PATH}/${EDL_FILE} COMMAND ${CODEGEN} --${CODETYPE} --untrusted ${CURRENT_ROOT_PATH}/${EDL_FILE} --search-path ${LOCAL_ROOT_PATH}/inc/host_inc/sgx --search-path ${SDK_PATH}/include) endif() ``` Use the code generation tool to generate auxiliary code based on the edl. Variables such as CODEGEN and CODETYPE are defined at the top of CMakeList.txt. --search-path is used to search for other edl files imported in test.edl. When SGX is used, the edl imported in test.edl indirectly depends on the edl of the SGX SDK. Therefore, the search path of the SGX SDK is also specified here. ```cmake set(CMAKE_C_FLAGS "-fstack-protector-all -W -Wall -Werror -Wextra -Werror=array-bounds -D_FORTIFY_SOURCE=2 -O2 -ftrapv -fPIE") set(CMAKE_EXE_LINKER_FLAGS "-Wl,-z,relro -Wl,-z,now -Wl,-z,noexecstack") ``` Set compile and link options. ```cmake if(CC_GP) if(${CMAKE_VERSION} VERSION_LESS "3.13.0") link_directories(${SECGEAR_INSTALL_PATH}) endif() add_executable(${OUTPUT} ${SOURCE_FILE} ${AUTO_FILES}) target_include_directories(${OUTPUT} PRIVATE ${LOCAL_ROOT_PATH}/inc/host_inc ${LOCAL_ROOT_PATH}/inc/host_inc/gp ${CMAKE_CURRENT_BINARY_DIR}) if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.13.0") target_link_directories(${OUTPUT} PRIVATE ${SECGEAR_INSTALL_PATH}) endif() endif() ``` In the case of iTrustee, set the search paths of the header file and compile the final non-secure binary. ```cmake if(CC_SGX) if(${CMAKE_VERSION} VERSION_LESS "3.13.0") link_directories(${SECGEAR_INSTALL_PATH}) endif() add_executable(${OUTPUT} ${SOURCE_FILE} ${AUTO_FILES}) target_include_directories(${OUTPUT} PRIVATE ${LOCAL_ROOT_PATH}/inc/host_inc ${LOCAL_ROOT_PATH}/inc/host_inc/sgx ${CMAKE_CURRENT_BINARY_DIR}) if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.13.0") target_link_directories(${OUTPUT} PRIVATE ${SECGEAR_INSTALL_PATH}) endif() endif() ``` In the case of SGX, set the search paths of the header file and compile the final non-secure binary. ```cmake if(CC_SIM) target_link_libraries(${OUTPUT} secgearsim) else() target_link_libraries(${OUTPUT} secgear) endif() set_target_properties(${OUTPUT} PROPERTIES SKIP_BUILD_RPATH TRUE) if(CC_GP) install(TARGETS ${OUTPUT} RUNTIME DESTINATION /vendor/bin/ PERMISSIONS OWNER_EXECUTE OWNER_WRITE OWNER_READ) endif() if(CC_SGX) install(TARGETS ${OUTPUT} RUNTIME DESTINATION ${CMAKE_BINARY_DIR}/bin/ PERMISSIONS OWNER_EXECUTE OWNER_WRITE OWNER_READ) endif() ``` Based on -DCC_SIM=ON or none transferred from cmake, linking secgear or secgearsim. Specify the installation path of the final binary. The non-secure side image of iTrustee must be installed on the specified whitelist. The whitelist configuration will be introduced below. ### 4 Write security side code, CMakeLists.txt and some configuration files #### 4.1 Create a new enclave directory and write hello.c ```c #include #include #include "test_t.h" #define TA_HELLO_WORLD "secGear hello world!" #define BUF_MAX 32 int get_string(char *buf) { strncpy(buf, TA_HELLO_WORLD, strlen(TA_HELLO_WORLD) + 1); return 0; } ``` Import the test_t.h generated by the automatic code generation tool, and then write the function according to the interface description in test.edl. #### 4.2 Write CMakeLists.txt ```cmake #set auto code prefix set(PREFIX test) #set sign key set(PEM Enclave_private.pem) ``` Set the private key file name used to sign the enclave binary. ```cmake #set sign tool set(SIGN_TOOL ${LOCAL_ROOT_PATH}/tools/sign_tool/sign_tool.sh) #set enclave src code set(SOURCE_FILES ${CMAKE_CURRENT_SOURCE_DIR}/hello.c) #set log level set(PRINT_LEVEL 3) add_definitions(-DPRINT_LEVEL=${PRINT_LEVEL}) ``` Set sign tool and the security side log printing level ```cmake if(CC_GP) #set signed output set(OUTPUT ${UUID}.sec) set(WHITE_LIST_0 /vendor/bin/helloworld) set(WHITE_LIST_1 /vendor/bin/secgear_test) set(WHITE_LIST_OWNER root) set(WHITELIST WHITE_LIST_0 WHITE_LIST_1) set(AUTO_FILES ${CMAKE_CURRENT_BINARY_DIR}/${PREFIX}_t.h ${CMAKE_CURRENT_BINARY_DIR}/${PREFIX}_t.c ${CMAKE_CURRENT_BINARY_DIR}/${PREFIX}_args.h) add_custom_command(OUTPUT ${AUTO_FILES} DEPENDS ${CURRENT_ROOT_PATH}/${EDL_FILE} COMMAND ${CODEGEN} --${CODETYPE} --trusted ${CURRENT_ROOT_PATH}/${EDL_FILE} --search-path ${LOCAL_ROOT_PATH}/inc/host_inc/gp) endif() ``` WHITE_LIS_X sets the whitelist of iTrustee, only the host binaries in these paths can call this secure image, and up to 8 list paths can be configured. WHITE_LIST_OWNER set user, this user will be applied to all whitelist paths. Finally, set the name of the security image after the final signing, and generate auxiliary code. ```cmake if(CC_SGX) set(OUTPUT enclave.signed.so) set(AUTO_FILES ${CMAKE_CURRENT_BINARY_DIR}/${PREFIX}_t.h ${CMAKE_CURRENT_BINARY_DIR}/${PREFIX}_t.c) add_custom_command(OUTPUT ${AUTO_FILES} DEPENDS ${CURRENT_ROOT_PATH}/${EDL_FILE} COMMAND ${CODEGEN} --${CODETYPE} --trusted ${CURRENT_ROOT_PATH}/${EDL_FILE} --search-path ${LOCAL_ROOT_PATH}/inc/host_inc/sgx --search-path ${SDK_PATH}/include) endif() ``` In the case of SGX, set the name of the security image after the final signing, and generate auxiliary code. ```cmake set(COMMON_C_FLAGS "-W -Wall -Werror -fno-short-enums \ -fno-omit-frame-pointer -fstack-protector \ -Wstack-protector --param ssp-buffer-size=4 -frecord-gcc-switches -Wextra -nostdinc -nodefaultlibs \ -fno-peephole -fno-peephole2 -Wno-main -Wno-error=unused-parameter \ -Wno-error=unused-but-set-variable -Wno-error=format-truncation=") set(COMMON_C_LINK_FLAGS "-Wl,-z,now -Wl,-z,relro -Wl,-z,noexecstack -Wl,-nostdlib -nodefaultlibs -nostartfiles") ``` Set the security side, no matter whether it is SGX or iTrustee will use some compilation and link options, for example, because the security side is different from the non-secure side, the default library of host OS cannot be used, so ```-nostdinc -nodefaultlibs -nostdlib -nodefaultlibs``` link options are introduced. ```cmake if(CC_GP) configure_file("${CMAKE_CURRENT_SOURCE_DIR}/manifest.txt.in" "${CMAKE_CURRENT_SOURCE_DIR}/manifest.txt") set(CMAKE_C_FLAGS "${COMMON_C_FLAGS} -march=armv8-a ") set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS} -s -fPIC") set(CMAKE_SHARED_LINKER_FLAGS "${COMMON_C_LINK_FLAGS} -Wl,-s") set(ITRUSTEE_TEEDIR ${SDK_PATH}/) set(ITRUSTEE_LIBC ${SDK_PATH}/thirdparty/open_source/musl/libc) if(${CMAKE_VERSION} VERSION_LESS "3.13.0") link_directories(${SECGEAR_INSTALL_PATH}) endif() add_library(${PREFIX} SHARED ${SOURCE_FILES} ${AUTO_FILES}) target_include_directories( ${PREFIX} PRIVATE ${CMAKE_CURRENT_BINARY_DIR} ${LOCAL_ROOT_PATH}/inc/host_inc ${LOCAL_ROOT_PATH}/inc/host_inc/gp ${LOCAL_ROOT_PATH}/inc/enclave_inc ${LOCAL_ROOT_PATH}/inc/enclave_inc/gp ${ITRUSTEE_TEEDIR}/include/TA ${ITRUSTEE_TEEDIR}/include/TA/huawei_ext ${ITRUSTEE_LIBC}/arch/aarch64 ${ITRUSTEE_LIBC}/ ${ITRUSTEE_LIBC}/arch/arm/bits ${ITRUSTEE_LIBC}/arch/generic ${ITRUSTEE_LIBC}/arch/arm ${LOCAL_ROOT_PATH}/inc/enclave_inc/gp/itrustee) if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.13.0") target_link_directories(${PREFIX} PRIVATE ${SECGEAR_INSTALL_PATH}) endif() foreach(WHITE_LIST ${WHITELIST}) add_definitions(-D${WHITE_LIST}="${${WHITE_LIST}}") endforeach(WHITE_LIST) add_definitions(-DWHITE_LIST_OWNER="${WHITE_LIST_OWNER}") target_link_libraries(${PREFIX} -lsecgear_tee) add_custom_command(TARGET ${PREFIX} POST_BUILD COMMAND bash ${SIGN_TOOL} -d sign -x trustzone -i lib${PREFIX}.so -c ${CMAKE_CURRENT_SOURCE_DIR}/manifest.txt -m ${CMAKE_CURRENT_SOURCE_DIR}/config_cloud.ini -o ${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT}) install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT} DESTINATION /data PERMISSIONS OWNER_EXECUTE OWNER_WRITE OWNER_READ GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE) endif() ``` In the case of iTrustee, generate the configuration file manifest.txt, and details of the configuration file will be explained later, specify some compilation options related to iTrustee, set the search paths of the header file and the link file, and build the enclave binary. Regarding the use of iTrustee ocall, there are some other notes, which will be introduced later. Then define the whitelist macro. Next, you need to link to the secgear_tee library, in which there are interfaces for generating random numbers, seal, unseal, etc. The last step is to sign and install. ```cmake if(CC_SGX) set(SGX_DIR ${SDK_PATH}) set(CMAKE_C_FLAGS "${COMMON_C_FLAGS} -m64 -fvisibility=hidden") set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS} -s") set(LINK_LIBRARY_PATH ${SGX_DIR}/lib64) if(CC_SIM) set(Trts_Library_Name sgx_trts_sim) set(Service_Library_Name sgx_tservice_sim) else() set(Trts_Library_Name sgx_trts) set(Service_Library_Name sgx_tservice) endif() set(Crypto_Library_Name sgx_tcrypto) set(CMAKE_SHARED_LINKER_FLAGS "${COMMON_C_LINK_FLAGS} -Wl,-z,defs -Wl,-pie -Bstatic -Bsymbolic -eenclave_entry \ -Wl,--export-dynamic -Wl,--defsym,__ImageBase=0 -Wl,--gc-sections -Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/Enclave.lds") if(${CMAKE_VERSION} VERSION_LESS "3.13.0") link_directories(${LINK_LIBRARY_PATH}) endif() add_library(${PREFIX} SHARED ${SOURCE_FILES} ${AUTO_FILES}) target_include_directories(${PREFIX} PRIVATE ${CMAKE_CURRENT_BINARY_DIR} ${SGX_DIR}/include/tlibc ${SGX_DIR}/include/libcxx ${SGX_DIR}/include ${LOCAL_ROOT_PATH}/inc/host_inc ${LOCAL_ROOT_PATH}/inc/host_inc/sgx) if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.13.0") target_link_directories(${PREFIX} PRIVATE ${LINK_LIBRARY_PATH}) endif() target_link_libraries(${PREFIX} -Wl,--whole-archive \ ${Trts_Library_Name} -Wl,--no-whole-archive \ -Wl,--start-group -lsgx_tstdc -lsgx_tcxx \ -l${Crypto_Library_Name} -l${Service_Library_Name} \ -Wl,--end-group) add_custom_command(TARGET ${PREFIX} POST_BUILD COMMAND openssl genrsa -3 -out ${PEM} 3072 COMMAND bash ${SIGN_TOOL} -d sign -x sgx -i lib${PREFIX}.so -k ${PEM} -o ${OUTPUT} -c ${CMAKE_CURRENT_SOURCE_DIR}/Enclave.config.xml) endif() ``` In the case of SGX, specify some compilation and link options related to SGX. When linking libraries, SGX and iTrustee are quite different. This is because iTrustee is a secure OS with more capabilities, such as musl libc and openssl. When compiling and link itrustee's enclave, there is no need to link some basic libraries. But SGX has no OS concept. The basic library interfaces to be called on the security side are all given in the SGX sdk in form of static libraries, so it requires us to link these static libraries, and in order to be able to use these static libraries correctly, some libraries must be linked between specified options, such as sgx_trts. For more detailed information, please refer to the Makefile of SGX examples. Finally, sign the enclave with the configuration file, which will be introduced later. Note that secGear does not currently support remote authentication. ```cmake set_target_properties(${PREFIX} PROPERTIES SKIP_BUILD_RPATH TRUE) ``` Set some safe compilation options. #### 4.3 Enclave image configuration file Write SGX enclave related configuration files The configuration content in the Enclave.config.xml and Enclave.lds files is the same as the official SGX configuration file. For details, please refer to the official development document. Write iTrustee related configuration files The gpd.ta.appID in the manifest.txt.in file is the uuid configuration item, which is dynamically generated, and the other configuration items can refer to the iTrustee development document. ### 5 build and install test [reference build & install](./sdk/docs/build_install.md) Log --- Non-secure side log record: Non-secure side development, similar to ordinary development, users can implement non-secure side application logs by themselves Security side log record: Security side development, due to restrictions on the different security capabilities of each platform, it is impossible to directly develop the log function like the non-secure side, Therefore, we provide the PrintInfo interface to record the security side log to the Syslog system. The related configuration files secgear and secgear.conf have been installed in the system directory during the build and install secGear phase. Note that when using on iTrustee, you need to import the secgear_log.h header file, but SGX does not need it. Because SGX implements the log function through ocall, the relevant code is in the auxiliary code. And when the configuration file is installed, you need to run "systemctl restart rsyslog" to make the log effective. Finally, in order to enable iTrustee logs to be dumped to the place specified in the configuration file, you also need to run /vendor/bin/tlogcat -f. The tlogcat tool is a part of the iTrustee sdk. The meaning of log level (set(PRINT_LEVEL 3)). ```c PRINT_ERROR 0 PRINT_WARNING 1 PRINT_STRACE 2 PRINT_DEBUG 3 ``` At present, there are some differences in the usage of the log function. After the iTrustee ocall function is stabilized, the usage will be unified. Use ocall --------- The secGear ocall function can be used normally on the SGX platform. There are currently restrictions with iTrustee: **Only the specified a3d88d2a-ae2a-4ea5-a37d-35fc5f607e9e uuid can be used.** **Only one programs enables ocall or error will be triggered.** **Config option ```ta.instanceKeepAlive``` shall not be enabled.** Moreover, if the underlying iTrustee does not enable ocall, the SDK will only report an error registration ocall failure, and the ecall function can be used normally. Seal, generate random number interface -------------------------------------- The related interface is defined in secgear_dataseal.h, secgear_random.h. For usage, please refer to examples/seal_data. Note: Since the feature for iTrustee to derive keys is still not perfect, seal related interfaces are not currently supported on the iTrustee platform. Remote authentication capability is currently not supported. ------------------------------------------------------------ secGear does not currently support plc, switchless and other about SGX features -------------------------------------------------------------------------------- Learning More About codegener ---------------------------- secGear introduces EDL (Enclave Description Language) and intermediate code generation tool codegener. EDL is compatible with Intel SGX's definition. - [Learn how to use codegener](./sdk/docs/codegener.md) Learning More About sign_tool ----------------------------- secGear introduces the signing tool to sign the enclave. - [Learn how to use signing tool](./sdk/docs/sign_tool.md) Milestone --------- Join openEuler/sig-confidential-computing to get more detailed information.