Undefined reference error

[t1m-k]

What's your question?

How to solve undefined reference error?

Additional Context

I guess that the error is connected somehow with OpenSSL. Here is context.
As I use debain-based kali linux, I have installed libssl-dev package. So now I have openssl binary at /usr/bin/openssl, all .h header files at /usr/include/opensll/, and such files as libssl.so or libcrypto.a are located at /usr/lib/x86_64-linux-gnu/.
openssl --version gives following output: OpenSSL 3.5.4 30 Sep 2025 (Library: OpenSSL 3.5.4 30 Sep 2025)

I build the library using command cmake -S . -B build -DOPENSSL_INCLUDE_DIR='/usr/include/openssl/' -DOPENSSL_CRYPTO_LIBRARY='/usr/lib/x86_64-linux-gnu/libssl.so' and there are no errors.
Then I use cmake --build build. And here is the output:

[  2%] Building CXX object example/CMakeFiles/print-claims.dir/print-claims.cpp.o
[  5%] Linking CXX executable print-claims
[  5%] Built target print-claims
[  8%] Building CXX object example/CMakeFiles/private-claims.dir/private-claims.cpp.o
[ 11%] Linking CXX executable private-claims
[ 11%] Built target private-claims
[ 14%] Building CXX object example/CMakeFiles/rsa-create.dir/rsa-create.cpp.o
[ 17%] Linking CXX executable rsa-create
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `jwt::helper::evp_pkey_handle::decrement_ref_count(evp_pkey_st*)':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:496:(.text._ZN3jwt6helper15evp_pkey_handle19decrement_ref_countEP11evp_pkey_st[_ZN3jwt6helper15evp_pkey_handle19decrement_ref_countEP11evp_pkey_st]+0x1b): undefined reference to `EVP_PKEY_free'
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `jwt::helper::make_mem_buf_bio()':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:502:(.text._ZN3jwt6helper16make_mem_buf_bioEv[_ZN3jwt6helper16make_mem_buf_bioEv]+0xf): undefined reference to `BIO_free_all'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:502:(.text._ZN3jwt6helper16make_mem_buf_bioEv[_ZN3jwt6helper16make_mem_buf_bioEv]+0x18): undefined reference to `BIO_s_mem'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:502:(.text._ZN3jwt6helper16make_mem_buf_bioEv[_ZN3jwt6helper16make_mem_buf_bioEv]+0x20): undefined reference to `BIO_new'
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `jwt::helper::make_mem_buf_bio(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:512:(.text._ZN3jwt6helper16make_mem_buf_bioERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE[_ZN3jwt6helper16make_mem_buf_bioERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE]+0x14): undefined reference to `BIO_free_all'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:512:(.text._ZN3jwt6helper16make_mem_buf_bioERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE[_ZN3jwt6helper16make_mem_buf_bioERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE]+0x3c): undefined reference to `BIO_new_mem_buf'
...

So the error occurs when trying to use openssl functions (EVP_PKEY_free, etc). Also, I use the only one version of openssl, so #311 doesn't fit the problem (as I think).

I have no more ideas about this, so opened the issue asking for help!

[prince-chrismc]

Welcome to building C++ :) Am I correct you are building jwt-cpp directly?

Please post the full output of both CMake commands

[t1m-k]

Thank you for the invitation, the world of real C++ is truly amazing :) It is my first C++ project which is enough big for such errors :)
Yes, I'm building jwt-cpp directly: I have cloned the repo from github and am building all the targets (include, tests, etc) together from source (but I'm beginner with cmake and can do something not correctly).
Here is output (it contains some warnings and "Could NOT find"s, but it is not quite on topic):

1. cmake -S . -B build -DOPENSSL_INCLUDE_DIR='/usr/include/openssl/' -DOPENSSL_CRYPTO_LIBRARY='/usr/lib/x86_64-linux-gnu/libssl.so':

-- Found OpenSSL: /usr/lib/x86_64-linux-gnu/libssl.so (Required is at least version "1.0.1")
-- jwt-cpp: using FetchContent for nlohmann-json required for tests
-- Using the multi-header code from /home/kali/work/dev/jwt-cpp/build/_deps/nlohmann_json-src/include/
-- The C compiler identification is GNU 14.3.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Could NOT find jsoncons (missing: jsoncons_DIR)
-- Could NOT find nlohmann_json (missing: nlohmann_json_DIR)
-- Could NOT find jsoncpp (missing: jsoncpp_DIR)
-- Could NOT find GTest (missing: GTEST_LIBRARY GTEST_INCLUDE_DIR GTEST_MAIN_LIBRARY) 
-- jwt-cpp: using FetchContent for GTest
CMake Deprecation Warning at build/_deps/googletest-src/CMakeLists.txt:4 (cmake_minimum_required):
  Compatibility with CMake < 3.10 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax
  to tell CMake that the project requires at least <min> but has been updated
  to work with policies introduced by <max> or earlier.


CMake Deprecation Warning at build/_deps/googletest-src/googlemock/CMakeLists.txt:39 (cmake_minimum_required):
  Compatibility with CMake < 3.10 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax
  to tell CMake that the project requires at least <min> but has been updated
  to work with policies introduced by <max> or earlier.


CMake Deprecation Warning at build/_deps/googletest-src/googletest/CMakeLists.txt:49 (cmake_minimum_required):
  Compatibility with CMake < 3.10 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax
  to tell CMake that the project requires at least <min> but has been updated
  to work with policies introduced by <max> or earlier.


-- Found Python: /usr/bin/python3.13 (found version "3.13.7") found components: Interpreter
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE
-- Could NOT find jsoncons (missing: jsoncons_DIR)
-- Could NOT find jsoncpp (missing: jsoncpp_DIR)
-- Configuring done (17.0s)
-- Generating done (6.3s)
-- Build files have been written to: /home/kali/work/dev/jwt-cpp/build

2. cmake --build build:

gmake[2]: Warning: File 'example/CMakeFiles/print-claims.dir/compiler_depend.make' has modification time 0.88 s in the future
gmake[2]: warning:  Clock skew detected.  Your build may be incomplete.
[  5%] Built target print-claims
gmake[2]: Warning: File 'example/CMakeFiles/private-claims.dir/compiler_depend.make' has modification time 0.67 s in the future
gmake[2]: warning:  Clock skew detected.  Your build may be incomplete.
[ 11%] Built target private-claims
gmake[2]: Warning: File 'example/CMakeFiles/rsa-create.dir/compiler_depend.make' has modification time 0.93 s in the future
[ 14%] Linking CXX executable rsa-create
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `jwt::helper::evp_pkey_handle::decrement_ref_count(evp_pkey_st*)':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:496:(.text._ZN3jwt6helper15evp_pkey_handle19decrement_ref_countEP11evp_pkey_st[_ZN3jwt6helper15evp_pkey_handle19decrement_ref_countEP11evp_pkey_st]+0x1b): undefined reference to `EVP_PKEY_free'
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `jwt::helper::make_mem_buf_bio()':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:502:(.text._ZN3jwt6helper16make_mem_buf_bioEv[_ZN3jwt6helper16make_mem_buf_bioEv]+0xf): undefined reference to `BIO_free_all'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:502:(.text._ZN3jwt6helper16make_mem_buf_bioEv[_ZN3jwt6helper16make_mem_buf_bioEv]+0x18): undefined reference to `BIO_s_mem'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:502:(.text._ZN3jwt6helper16make_mem_buf_bioEv[_ZN3jwt6helper16make_mem_buf_bioEv]+0x20): undefined reference to `BIO_new'
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `jwt::helper::make_mem_buf_bio(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:512:(.text._ZN3jwt6helper16make_mem_buf_bioERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE[_ZN3jwt6helper16make_mem_buf_bioERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE]+0x14): undefined reference to `BIO_free_all'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:512:(.text._ZN3jwt6helper16make_mem_buf_bioERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE[_ZN3jwt6helper16make_mem_buf_bioERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE]+0x3c): undefined reference to `BIO_new_mem_buf'
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `jwt::helper::make_evp_md_ctx()':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:531:(.text._ZN3jwt6helper15make_evp_md_ctxEv[_ZN3jwt6helper15make_evp_md_ctxEv]+0xf): undefined reference to `EVP_MD_CTX_free'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:531:(.text._ZN3jwt6helper15make_evp_md_ctxEv[_ZN3jwt6helper15make_evp_md_ctxEv]+0x18): undefined reference to `EVP_MD_CTX_new'
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `jwt::algorithm::rsa::sign(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::error_code&) const':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:1499:(.text._ZNK3jwt9algorithm3rsa4signERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERSt10error_code[_ZNK3jwt9algorithm3rsa4signERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERSt10error_code]+0xb6): undefined reference to `EVP_DigestInit'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:1504:(.text._ZNK3jwt9algorithm3rsa4signERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERSt10error_code[_ZNK3jwt9algorithm3rsa4signERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERSt10error_code]+0x11b): undefined reference to `EVP_PKEY_get_size'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:1507:(.text._ZNK3jwt9algorithm3rsa4signERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERSt10error_code[_ZNK3jwt9algorithm3rsa4signERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERSt10error_code]+0x18e): undefined reference to `EVP_DigestUpdate'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:1511:(.text._ZNK3jwt9algorithm3rsa4signERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERSt10error_code[_ZNK3jwt9algorithm3rsa4signERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERSt10error_code]+0x21a): undefined reference to `EVP_SignFinal'
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `jwt::algorithm::rs256::rs256(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:2108:(.text._ZN3jwt9algorithm5rs256C2ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES9_S9_S9_[_ZN3jwt9algorithm5rs256C5ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES9_S9_S9_]+0x61): undefined reference to `EVP_sha256'
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > jwt::helper::write_bio_to_string<jwt::error::rsa_error>(std::unique_ptr<bio_st, void (*)(bio_st*)>&, std::error_code&)':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:518:(.text._ZN3jwt6helper19write_bio_to_stringINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERSt10unique_ptrI6bio_stPFvPSB_EERSt10error_code[_ZN3jwt6helper19write_bio_to_stringINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERSt10unique_ptrI6bio_stPFvPSB_EERSt10error_code]+0x3e): undefined reference to `BIO_ctrl'
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `jwt::helper::evp_pkey_handle jwt::helper::load_private_key_from_string<jwt::error::rsa_error>(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::error_code&)':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:793:(.text._ZN3jwt6helper28load_private_key_from_stringINS_5error9rsa_errorEEENS0_15evp_pkey_handleERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESC_RSt10error_code[_ZN3jwt6helper28load_private_key_from_stringINS_5error9rsa_errorEEENS0_15evp_pkey_handleERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESC_RSt10error_code]+0xcc): undefined reference to `BIO_write'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:797:(.text._ZN3jwt6helper28load_private_key_from_stringINS_5error9rsa_errorEEENS0_15evp_pkey_handleERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESC_RSt10error_code[_ZN3jwt6helper28load_private_key_from_stringINS_5error9rsa_errorEEENS0_15evp_pkey_handleERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESC_RSt10error_code]+0x14c): undefined reference to `PEM_read_bio_PrivateKey'
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `jwt::helper::evp_pkey_handle jwt::helper::load_public_key_from_string<jwt::error::rsa_error>(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::error_code&)':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:733:(.text._ZN3jwt6helper27load_public_key_from_stringINS_5error9rsa_errorEEENS0_15evp_pkey_handleERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESC_RSt10error_code[_ZN3jwt6helper27load_public_key_from_stringINS_5error9rsa_errorEEENS0_15evp_pkey_handleERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESC_RSt10error_code]+0x211): undefined reference to `BIO_write'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:744:(.text._ZN3jwt6helper27load_public_key_from_stringINS_5error9rsa_errorEEENS0_15evp_pkey_handleERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESC_RSt10error_code[_ZN3jwt6helper27load_public_key_from_stringINS_5error9rsa_errorEEENS0_15evp_pkey_handleERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESC_RSt10error_code]+0x33a): undefined reference to `BIO_write'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:750:(.text._ZN3jwt6helper27load_public_key_from_stringINS_5error9rsa_errorEEENS0_15evp_pkey_handleERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESC_RSt10error_code[_ZN3jwt6helper27load_public_key_from_stringINS_5error9rsa_errorEEENS0_15evp_pkey_handleERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESC_RSt10error_code]+0x3c3): undefined reference to `PEM_read_bio_PUBKEY'
/usr/bin/ld: CMakeFiles/rsa-create.dir/rsa-create.cpp.o: in function `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > jwt::helper::extract_pubkey_from_cert<jwt::error::rsa_error>(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::error_code&)':
/home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:553:(.text._ZN3jwt6helper24extract_pubkey_from_certINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKS9_SB_RSt10error_code[_ZN3jwt6helper24extract_pubkey_from_certINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKS9_SB_RSt10error_code]+0xd3): undefined reference to `X509_free'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:553:(.text._ZN3jwt6helper24extract_pubkey_from_certINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKS9_SB_RSt10error_code[_ZN3jwt6helper24extract_pubkey_from_certINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKS9_SB_RSt10error_code]+0x10a): undefined reference to `PEM_read_bio_X509'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:559:(.text._ZN3jwt6helper24extract_pubkey_from_certINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKS9_SB_RSt10error_code[_ZN3jwt6helper24extract_pubkey_from_certINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKS9_SB_RSt10error_code]+0x17b): undefined reference to `EVP_PKEY_free'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:559:(.text._ZN3jwt6helper24extract_pubkey_from_certINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKS9_SB_RSt10error_code[_ZN3jwt6helper24extract_pubkey_from_certINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKS9_SB_RSt10error_code]+0x196): undefined reference to `X509_get_pubkey'
/usr/bin/ld: /home/kali/work/dev/jwt-cpp/include/jwt-cpp/jwt.h:564:(.text._ZN3jwt6helper24extract_pubkey_from_certINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKS9_SB_RSt10error_code[_ZN3jwt6helper24extract_pubkey_from_certINS_5error9rsa_errorEEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKS9_SB_RSt10error_code]+0x22c): undefined reference to `PEM_write_bio_PUBKEY'
collect2: error: ld returned 1 exit status
gmake[2]: *** [example/CMakeFiles/rsa-create.dir/build.make:103: example/rsa-create] Error 1
gmake[1]: *** [CMakeFiles/Makefile2:395: example/CMakeFiles/rsa-create.dir/all] Error 2
gmake: *** [Makefile:146: all] Error 2

[t1m-k]

Some news? I don't have any(

[prince-chrismc]

Whoops! I looked at this and completely forgot to answer.

This does look you've installed too many versions of OpenSSL. https://pkg.kali.org/pkg/openssl you should be seeing 3.5.5 if you installed it from kali dristro.

Try deleting the build folder and run cmake configure without pass any extra flags.

[t1m-k]

Sorry for late reply, I didn't have time(
Based on your answer I ran following commands:
sudo apt remove openssl -y - to remove current openssl version
sudo apt install libssl-dev openssl -y - to install newest 3.5.5 version
sudo apt autoremove - to clear extra packages
Then I ran cmake -S . -B build without any extra flags and cmake succesfully found openssl and built everything!
cmake --build build had no errors, too.
Thank you!

[prince-chrismc]

Cheers

[t1m-k]

Add some comments for those who also have this issue.
Package openssl gives no required library files as .so etc. Package libssl-dev contains them.
But, there is no libssl-dev package by default in kali and if you run sudo apt install libssl-dev you may get Error: Unable to locate package libssl-dev. In this case update packages list: sudo apt update.
The error that caused this issue to be created occurred because I had two versions of openssl installed: I had old openssl package and new libssl-dev. So I guess if you have the newest version of both, there should be no error.
Solution that worked for me removes all openssl so programs that need it will install many packages (e.g. python3-jango) with builtin openssl, and then clears them by autoremove.
That's why it looks like sudo apt upgrade openssl libssl-dev should work, too.