CMake中OpenSSL加密的静态链接

Question

我需要为MIPS设备制作交叉编译的OpenSSL。我试过按照文档。将OPENSSL_USE_STATIC_LIBS设置为true并将target_link_libraries设置为您需要的库文件。

的CMakeLists.txt：

compileAsC99()

if(NOT ${use_http})
    message(FATAL_ERROR "program being generated without HTTP support")
endif()

set(program_c_files
    ...
)

set(program_h_files
    ...
)

include_directories(...)

add_executable(program ${program_c_files} ${program_h_files})

set(OPENSSL_USE_STATIC_LIBS TRUE)
#target_link_libraries(program OpenSSL::Crypto)
target_link_libraries(program /home/program/mips/lib/libssl.so.1.1)
target_link_libraries(program /home/program/mips/lib/libcrypto.so.1.1)

它编译好没有警告，但检查生成的二进制文件告诉我它仍然是共享库。

readelf -d程序：

Dynamic section at offset 0x1bc contains 35 entries:
  Tag        Type                         Name/Value
 0x00000001 (NEEDED)                     Shared library: [libssl.so.1.1]
 0x00000001 (NEEDED)                     Shared library: [libcrypto.so.1.1]
 0x0000000f (RPATH)                      Library rpath: [/home/program/mips/lib]

我不明白我做错了什么。

编辑：已经看过Linking statically OpenSSL crypto library in CMake但它并没有告诉我任何新的东西。

编辑2：根据回复更新了CMakeLists.txt文件：CMakeLists.txt：

compileAsC99()

if(NOT ${use_http})
    message(FATAL_ERROR "program being generated without HTTP support")
endif()

set(program_c_files
    ...
)

set(program_h_files
    ...
)

include_directories(...)

add_executable(program ${program_c_files} ${program_h_files})

find_package(OpenSSL REQUIRED)
if(OPENSSL_FOUND)
set(OPENSSL_USE_STATIC_LIBS TRUE)
message("OPENSSL FOUND!")
endif()
target_link_libraries(program OpenSSL::Crypto)

输出：

-- IoT Client SDK Version = 1.2.11
-- Provisioning client OFF
-- target architecture: GENERIC
-- Cross compiling not using pkg-config
-- Found CURL: /home/program/mips/lib/libcurl.a (found version "7.63.0")
-- Found CURL: /home/program/mips/lib/libcurl.a
-- target architecture: GENERIC
-- target architecture: GENERIC
-- target architecture: GENERIC
-- target architecture: GENERIC
-- iothub architecture: GENERIC
OPENSSL FOUND!
-- Configuring done
-- Generating done

编辑繁荣：如果你，未来的人，遇到undefined reference to dlopen，我将以下内容添加到我的CMakeLists.txt文件中

target_link_libraries(program ${CMAKE_DL_LIBS})

Answer 1

设置为TRUE，变量OPENSSL_USE_STATIC_LIBS强制find_package(OpenSSL)搜索静态库。因此，此变量仅适用于该调用，如果您使用其结果：

set(OPENSSL_USE_STATIC_LIBS TRUE)
find_package(OpenSSL REQUIRED)
target_link_libraries(program OpenSSL::Crypto)

---

如果你已经在没有设置cmake的情况下执行了OPENSSL_USE_STATIC_LIBS，那么你需要在新的尝试之前删除CMake缓存（构建目录下的CMakeCache.txt）。否则，将使用已找到的（共享！）库，并且不会执行重新搜索。