setting up an environment for cross-compiling static libssh-projects

[Peter Lustig]

Hi yall,

my goal ist to create an environment for cross-compiling static libssh-projects.
• cross-compilation: host: linux (ubuntu), target: windows 64bit, architectur x86
• static: no dynamic libraries needed during runtime nor compilationtime
• libssh1, no libssh2: I do need server support too.
To reach my goal I spent days (two weeks now) for theory and praxis, but I couldn’t get there. Before I list what I did so far, my questions:

1. Could u tell me, what I did wrong and what I need to do/change and of course why?
2. Could u write a (quick) mini HOW-TO for this purpose with all third library dependencies (libz, libssl form what I know) with standard directory configurations

What I did so far: Latest I set up a new VM with Ubuntu (untouched system). Then:

sudo apt-get install mingw-64

sudo apt-get install cmake

So mingw is located in /usr/bin /usr/x86_64-w64-mingw32/include /usr/x86_64-w64-mingw32/lib
Dowloading tarballs for zlib, openssl and libssh and taring them in /home/affenarsch/Downloads then cd to zlib and:

sed -e s/"PREFIX ="/"PREFIX = x86_64-w64-mingw32-"/ -i win64/Makefile.gcc

make -f win64/Makefile.gcc

#sudo BINARY_PATH=/usr/bin \
INCLUDE_PATH=/usr/x86_64-w64-mingw32/include \
LIBRARY_PATH=/ usr/x86_64-w64-mingw32/lib \
make -f win64/Makefile.gcc install

make install

zlib is in /usr/local/x86_64-w64-mingw32/include and /usr/local/x86_64-w64-mingw32/lib

in directory of openssl:

./Configure --cross-compile-prefix=x86_64-w64-mingw32- mingw64

make

make install

SSl is located in /usr/local/ssl
Finally I created a directory for the libssh-build /home/affenarsch/Download/build and created a toolchainfile for cmake /home/affenarsch/Download/file.cmake with following content:

set(CMAKE_SYSTEM_NAME Windows)
set(COMPILER_PREFIX "x86_64-w64-mingw32")

set(CMAKE_C_COMPILER /usr/bin/${COMPILER_PREFIX}-gcc)
set(CMAKE_CXX_COMPILER /usr/bin/${COMPILER_PREFIX}-g++)
set(CMAKE_RC_COMPILER /usr/bin/${COMPILER_PREFIX}-windres)

SET(CMAKE_FIND_ROOT_PATH /usr/${COMPILER_PREFIX} /usr/local/ssl /usr/local//${COMPILER_PREFIX})

Did some changes to the DefineOptions.cmake file of libssh:

option(WITH_GSSAPI "Build with GSSAPI support" ON)
option(WITH_ZLIB "Build with ZLIB support" ON)
option(WITH_SSH1 "Build with SSH1 support" ON)
option(WITH_SFTP "Build with SFTP support" ON)
option(WITH_SERVER "Build with SSH server support" ON)
option(WITH_STATIC_LIB "Build with a static library" ON)
option(WITH_DEBUG_CRYPTO "Build with cryto debug output" OFF)
option(WITH_DEBUG_CALLTRACE "Build with calltrace debug output" ON)
option(WITH_GCRYPT "Compile against libgcrypt" OFF)
option(WITH_PCAP "Compile with Pcap generation support" ON)
option(WITH_INTERNAL_DOC "Compile doxygen internal documentation" OFF)
option(WITH_TESTING "Build with unit tests" OFF)
option(WITH_CLIENT_TESTING "Build with client tests; requires a running sshd" OFF)
option(WITH_BENCHMARKS "Build benchmarks tools" OFF)
option(WITH_EXAMPLES "Build examples" ON)
option(WITH_NACL "Build with libnacl (curve25519" ON)
if (WITH_ZLIB)
set(WITH_LIBZ ON)
else (WITH_ZLIB)
set(WITH_LIBZ OFF)
endif (WITH_ZLIB)

if(WITH_BENCHMARKS)
set(WITH_TESTING ON)
endif(WITH_BENCHMARKS)

if (WITH_TESTING)
set(WITH_STATIC_LIB ON)
endif (WITH_TESTING)

if (WITH_NACL)
set(WITH_NACL ON)
endif (WITH_NACL)

then, from /home/affenarsch/Downloads/build :

cmake /home/affenarsch/Downloads/libssh-0.7.2 -DCMAKE_TOOLCHAIN_FILE=/home/affenarsch/Downloads/file.cmake

make

sudo make install

libssh is located in /usr/local/local/lib and /usr/local/include (in directory libssh: /usr/local/include/libssh actually ).
And i did the build once (no „old wood“ from builds before).

compiler/libtest:
set up sample code in main.c of my home-directory and tried to gcc:

/usr/bin/x86_64-w64-mingw32-gcc -static main.c -I/usr/local/include -I/usr/local/x86_64-w64-mingw32/include -I/usr/x86_64-w64-mingw32/include -L/usr/local/lib -L/usr/local/x86_64-w64-mingw32/lib -L/usr/x86_64-w64-mingw32/lib -lssh -lssl -lcrypto -lws2_32 -lz

It found all libs I try to link, but I got „undefined references“- errors. nm’ing libssh.a is showing undefined symbols for used functions like new_ssh()?!
I tried and read so much! Please help. What else do u need for problem solving? Or: Just some How-to cmdlines do it the right way?- And I diff the solution to my wrong way, to get the problem/mistake.

I am totally ok with an solution leaning on mxe.

Thank you very much.