OPENSSL_ROOT_DIR for cmake

Question

I have built & installed openssl 1.1.1 on my system:

openssl version
OpenSSL 1.1.1h-dev  xx XXX xxxx

The respective libcrypto.so and libssl.so are in /usr/local/lib64, headers in /usr/local/include. I created /etc/ld.so.conf.d/usrlocal.conf and added /usr/local/lib64 there to make sure the .so are loadable.

There is an older version (1.0.2) in /usr/lib64/ and /usr/include that i need to keep for other dependencies.

I am trying to compile OQS library (https://github.com/open-quantum-safe/liboqs) that requires

find_package(OpenSSL 1.1.1 REQUIRED)

When I try to compile the library, I get

CMake Error at /usr/local/share/cmake-3.17/Modules/FindPackageHandleStandardArgs.cmake:164 (message):
  Could NOT find OpenSSL, try to set the path to OpenSSL root folder in the
  system variable OPENSSL_ROOT_DIR: Found unsuitable version "1.0.2k", but
  required is at least "1.1.1" (found /usr/lib64/libcrypto.so)
Call Stack (most recent call first):
  /usr/local/share/cmake-3.17/Modules/FindPackageHandleStandardArgs.cmake:443 (_FPHSA_FAILURE_MESSAGE)
  /usr/local/share/cmake-3.17/Modules/FindOpenSSL.cmake:450 (find_package_handle_standard_args)
  CMakeLists.txt:26 (find_package)

I have tried setting OPENSSL_ROOT_DIR to almost any value imaginable without any result; the error remains.

It seems to me thatcmake only attempts to check OPENSSL_ROOT_DIR as last attempt, and that it terminates exploration for appropriate library version after finding the first suitable version...

Now the question is obvious - how to force CMAKE to find appropriate OpenSSL version?

UPDATE

(debunked in next update) As @Tsyvarev suggested in the comments, setting OPENSSL_ROOT_DIR as environment variable helped. That means no set(OPENSSL_ROOT_DIR ...) in CMakeLists.txt or -DOPENSSL_ROOT_DIR with cmake command, but export OPENSSL_ROOT_DIR=... is what helped find_package to find the correct version.

I am still running into issues with OQS, yet this time I believe they are caused by a different issue.

lib/liboqs.a(fips202x4.c.o): In function `keccak_squeezeblocks4x.constprop.1':
fips202x4.c:(.text.keccak_squeezeblocks4x.constprop.1+0x6b): undefined reference to `KeccakP1600times4_PermuteAll_24rounds'

UPDATE 2

I am actually using OQS in another CMakeLists.txt via FetchContent as:

FetchContent_Declare(liboqs 
    GIT_REPOSITORY https://github.com/onavratil-monetplus/liboqs 
    #GIT_TAG 0.2.0 
) 

I made my custom fork and tweaked their CMakeLists.txt to export targets so that I can link appropriate dependencies to my binary in cmake:

target_link_libraries(myexecutable PUBLIC OQS::oqs)

The strange thing is, if I let OQS find OpenSSL on its own, I will get to the same result as in the original answer - no matter if I use -D, set() or export =. However, if on my top level CMakeLists.txt i manually call find_package(OpenSSL 1.1.1 REQUIRED), it succeeds, respective variables OPENSSL_FOUND etc are set properly and OQS compiles. Btw I use cmake version 3.17.2.

After all it was this edit (finding OPENSSL myself) that fixed the problem, this way, -DOPENSSL_ROOT_DIR=/usr/local works as well.

Answer 1

I installed libssl-dev (as suggested at the bottom of the failed cmake build output) and it worked first time.

Note, that the development header packages of SSL libs are named differently on different distros. E.g. libssl-dev, libssl-devel, openssl-dev etc.