如何在 C/C++ 中使用带有 OpenSSL 的静态链接

Question

我使用 Openssl 用 C 和 C++ 编写了简单的应用程序。我这样编译它们：

gcc openssltest.c -o openssltest -lcrypto
g++ openssltest.cpp -o openssltest -lcrypto

一切都好，但只有在您安装了 Openssl 时。

我想编译它，以便我可以在没有 Openssl 安装端的操作系统（类 linux 操作系统）上运行它们。我试过这个：

gcc -c openssltest.c -lcrypto -static
gcc openssltest.o -o openssltest -lcrypto -static

对于 C++ 也是如此：

g++ -c openssltest.cpp -lcrypto -static
g++ openssltest.o -o openssltest -lcrypto -static

但是有那些错误：

/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_globallookup':
(.text+0x19): undefined reference to `dlopen'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_globallookup':
(.text+0x2c): undefined reference to `dlsym'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_globallookup':
(.text+0x37): undefined reference to `dlclose'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_bind_func':
(.text+0x354): undefined reference to `dlsym'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_bind_func':
(.text+0x3fb): undefined reference to `dlerror'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_bind_var':
(.text+0x474): undefined reference to `dlsym'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_bind_var':
(.text+0x52e): undefined reference to `dlerror'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_load':
(.text+0x5a2): undefined reference to `dlopen'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_load':
(.text+0x60b): undefined reference to `dlclose'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_load':
(.text+0x638): undefined reference to `dlerror'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_pathbyaddr':
(.text+0x6cd): undefined reference to `dladdr'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_pathbyaddr':
(.text+0x731): undefined reference to `dlerror'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_unload':
(.text+0x78a): undefined reference to `dlclose'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `bio_zlib_free':
(.text+0x4d): undefined reference to `inflateEnd'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `bio_zlib_free':
(.text+0x6b): undefined reference to `deflateEnd'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `bio_zlib_ctrl':
(.text+0x284): undefined reference to `deflate'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `bio_zlib_ctrl':
(.text+0x342): undefined reference to `zError'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `zlib_stateful_expand_block':
(.text+0x411): undefined reference to `inflate'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `zlib_stateful_compress_block':
(.text+0x4ca): undefined reference to `deflate'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `zlib_stateful_finish':
(.text+0x51f): undefined reference to `inflateEnd'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `zlib_stateful_finish':
(.text+0x528): undefined reference to `deflateEnd'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `zlib_stateful_init':
(.text+0x5d7): undefined reference to `inflateInit_'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `zlib_stateful_init':
(.text+0x659): undefined reference to `deflateInit_'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `bio_zlib_read':
(.text+0x893): undefined reference to `inflate'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `bio_zlib_read':
(.text+0x90d): undefined reference to `zError'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `bio_zlib_read':
(.text+0x97c): undefined reference to `inflateInit_'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `bio_zlib_write':
(.text+0xa6f): undefined reference to `deflate'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `bio_zlib_write':
(.text+0xaec): undefined reference to `zError'
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libcrypto.a(c_zlib.o): In function `bio_zlib_write':
(.text+0xb7e): undefined reference to `deflateInit_'
collect2: error: ld returned 1 exit status

我怎样才能做到这一点？我记得前段时间我这样做了，但是现在，呃，忘记了怎么做。我在 Ubuntu 13.04 x64 - 这可能是个问题吗？

Answer 1

我在尝试使用 openssl 库静态编译一个简单的 DES 程序时遇到了类似的问题。我使用了-lcrypto -lz -ldl -static-libgcc，它对我有用。没有警告或错误。

Answer 2

您需要注意，库需要作为静态链接的 *.a 文件提供。如果不是，那么编译要么失败，要么你最终得到一个动态链接的可执行文件。

如果这得到太多 PITA（所有库依赖项都需要静态编译到，以及它们的 dep 等等），请使用 buildroot 之类的东西

Answer 3

修补程序：尝试静态链接 libdl。

如果这不起作用，恕我直言，您的 libcrypto.a 编译错误。

Answer 4

我和你有同样的问题。这是为我解决它的命令：

gcc yourfile.c -o yourfile -static -lcrypto -lz -ldl

它会生成此警告：

/usr/lib/gcc/i686-linux-gnu/4.7/../../../i386-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_globallookup': (.text+0x1b): warning: Using 'dlopen' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking

但可执行文件仍然有效。