How to force Qt to use the right libssl which is not anymore the default libssl.so?

[mbruel]

Hi,
I'm having an "old" server running Debian 8 with Qt v5.8 which uses libssl.so.1.0.0.
I've installed a new service which uses libssl.so.1.1.
So now, the system is using that new version.

$ ll /usr/lib/x86_64-linux-gnu/libssl.so*
lrwxrwxrwx 1 root root   13 Apr 21  2020 /usr/lib/x86_64-linux-gnu/libssl.so -> libssl.so.1.1
-rw-r--r-- 1 root root 386K Sep 25  2019 /usr/lib/x86_64-linux-gnu/libssl.so.1.0.0
-rw-r--r-- 1 root root 580K Apr 21  2020 /usr/lib/x86_64-linux-gnu/libssl.so.1.1

How could I tell Qt to not use /usr/lib/x86_64-linux-gnu/libssl.so but /usr/lib/x86_64-linux-gnu/libssl.so.1.1 ?
Any ideas?

Cause all my apps using QSslSockets now crash with:

qt.network.ssl: QSslSocket: cannot resolve CRYPTO_num_locks
qt.network.ssl: QSslSocket: cannot resolve CRYPTO_set_id_callback
qt.network.ssl: QSslSocket: cannot resolve CRYPTO_set_locking_callback
qt.network.ssl: QSslSocket: cannot resolve ERR_free_strings
qt.network.ssl: QSslSocket: cannot resolve EVP_CIPHER_CTX_cleanup
qt.network.ssl: QSslSocket: cannot resolve EVP_CIPHER_CTX_init
qt.network.ssl: QSslSocket: cannot resolve sk_new_null
qt.network.ssl: QSslSocket: cannot resolve sk_push
qt.network.ssl: QSslSocket: cannot resolve sk_free
qt.network.ssl: QSslSocket: cannot resolve sk_num
qt.network.ssl: QSslSocket: cannot resolve sk_pop_free
qt.network.ssl: QSslSocket: cannot resolve sk_value
qt.network.ssl: QSslSocket: cannot resolve SSL_library_init
qt.network.ssl: QSslSocket: cannot resolve SSL_load_error_strings
qt.network.ssl: QSslSocket: cannot resolve SSL_get_ex_new_index
qt.network.ssl: QSslSocket: cannot resolve SSLv2_client_method
qt.network.ssl: QSslSocket: cannot resolve SSLv3_client_method
qt.network.ssl: QSslSocket: cannot resolve SSLv23_client_method
qt.network.ssl: QSslSocket: cannot resolve SSLv2_server_method
qt.network.ssl: QSslSocket: cannot resolve SSLv3_server_method
qt.network.ssl: QSslSocket: cannot resolve SSLv23_server_method
qt.network.ssl: QSslSocket: cannot resolve X509_STORE_CTX_get_chain
qt.network.ssl: QSslSocket: cannot resolve OPENSSL_add_all_algorithms_noconf
qt.network.ssl: QSslSocket: cannot resolve OPENSSL_add_all_algorithms_conf
qt.network.ssl: QSslSocket: cannot resolve SSLeay
qt.network.ssl: QSslSocket: cannot resolve SSLeay_version
qt.network.ssl: QSslSocket: cannot call unresolved function CRYPTO_num_locks
qt.network.ssl: QSslSocket: cannot call unresolved function CRYPTO_set_id_callback
qt.network.ssl: QSslSocket: cannot call unresolved function CRYPTO_set_locking_callback
qt.network.ssl: QSslSocket: cannot call unresolved function SSL_library_init
qt.network.ssl: QSslSocket: cannot call unresolved function SSLv23_client_method
qt.network.ssl: QSslSocket: cannot call unresolved function sk_num
Segmentation fault

[nagesh]

@mbruel It's already /usr/lib/x86_64-linux-gnu/libssl.so is symlink to libssl.so.1.1

[mbruel]

@nagesh well that's the problem. Qt v4.8 needs libssl.so.1.0.0 (and not the 1.1)
So if change the symlink /usr/lib/x86_64-linux-gnu/libssl.so to point on 1.0.0 everything is working back to normal.
But I've now other services that needs 1.1. So the /usr/lib/x86_64-linux-gnu/libssl.so should point on 1.1.

[jsulm]

@mbruel You can simply put the 1.0.0 version next to your binary (or somewhere else and point to it using LD_LIBRARY_PATH).

[mbruel]

@jsulm yep that is what I just did and it is working.
I've copied /usr/lib/x86_64-linux-gnu/libssl.so.1.0.0 to libssl.so (no version) in a folder and set LD_LIBRARY_PATH on it...