OPENSSL Issue: Failed to load OpenSSL legacy provider

[Pruthwiraj-Kumar-Deo]

Hi Team
I am currently cross compiling my binary with OPENSSL (3.1.1) and POCO (1.11.6) Library .

I have built my OPENSSL library with 'no-asm no-idea no-mdc2 no-rc5 no-ssl3 enable-weak-ssl-ciphers' flags.
and built POCO library with '--poquito --no-tests --no-samples --omit=CppUnit,CppUnit/WinTestRunner,XML,JSON,Data,Data/SQLite,Data/ODBC,Data/MySQL,MongoDB,Zip,Encodings,Redis --static' flags.

Then I built my binary using above two libraries. But while running the binary I am getting an exception :

Crypto Exception: Failed to load OpenSSL legacy provider

When I tracked it down , found that it is coming from
src/Crypto/src/OpenSSLInitializer.cpp:140: if (!_legacyProvider) throw CryptoException("Failed to load OpenSSL legacy provider");

So I tried to provide the legacy.so in /usr/lib during run time as well I set
openssl_conf = openssl_init

[openssl_init]
providers = provider_sect

[provider_sect]
default = default_sect
legacy = legacy_sect

[legacy_sect]
activate = 1

in /etc/ssl/openssl.cnf also. But still facing the same issue. So, I have some query about it.

1. Why is the exception reoccurring even if I provide the legacy.so at runtime ?
   Should I write a logic to load the legacy.so at runtime additionally?
2. Are OPENSSL (3.1.1) and POCO (1.11.6) Libraries compactible to each other ?
   Or should I go for any other version combination ?
   Is there any way we can know about the compactible versions of OPENSSL & POCO with each other ?
3. Any other library (other than legacy.so )is required ?

[t8m]

The legacy.so must be placed in a directory where the libcrypto looks for it. make install should place it there.