How to use static linking with OpenSSL in C/C++

Question

I wrote simple apps with Openssl in C and C++. I compile them like this:

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

And its all ok but only, when you have Openssl installed.

I would like to compile it that I can run them on OS where theres no Openssl installend (linux-like OS). I tried this:

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

and same for C++:

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

But have those errors:

/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

How can I make this? I remember that a while ago I did this but now, erm, forgot how to do it. Im on Ubuntu 13.04 x64 - can it be an issue?

Answer 1

You need to be aware that libraries need to availiable as statically linked *.a files. If they are not, then compilation will either fail or you end up with a dynamically linked executable.

If this gets too much PITA (all the libraries dependencies need to be statically compiled to, and their deps too and so on) use something like buildroot