/usr/include/ is in libace-ssl-dev 6.0.1-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/ace/
/usr/include/ace/SSL/
/usr/include/ace/SSL/SSL_SOCK.h
/usr/include/ace/SSL/SSL_SOCK_Connector.h
/usr/include/ace/SSL/SSL_SOCK.inl
/usr/include/ace/SSL/SSL_Asynch_Stream.h
/usr/include/ace/SSL/SSL_SOCK_Stream.h
/usr/include/ace/SSL/SSL_Context.inl
/usr/include/ace/SSL/SSL_Context.h
/usr/include/ace/SSL/SSL_SOCK_Acceptor.inl
/usr/include/ace/SSL/SSL_SOCK_Connector.inl
/usr/include/ace/SSL/SSL_Export.h
/usr/include/ace/SSL/SSL_SOCK_Stream.inl
/usr/include/ace/SSL/sslconf.h
/usr/include/ace/SSL/SSL_Asynch_Stream.inl
/usr/include/ace/SSL/SSL_SOCK_Acceptor.h
/usr/include/ace/SSL/SSL_Asynch_BIO.h