Fail to build against OpenSSL 4.0

[teward]

OpenSSL 4.0 is out, and there is no support available for it in XCA.

This was reported downstream in Debian. The contents of the Debian bug report is here:

OpenSSL 4.0 is in Debian experimental. This package fails to build against it:

| [  5%] Building CXX object CMakeFiles/xcalib.dir/lib/pki_pkcs12.cpp.o
| /usr/bin/c++ -DOPENSSL_SUPPRESS_DEPRECATED -DQT_CORE_LIB -DQT_GUI_LIB -DQT_HELP_LIB -DQT_MESSAGELOGCONTEXT -DQT_NO_DEBUG -DQT_SQL_LIB -DQT_WIDGETS_LIB -I/build/reproducible-path/xca-2.9.0/obj-x86_64-linux-gnu/xcalib_autogen/include -I/build/reproducible-path/xca-2.9.0/obj-x86_64-linux-gnu -I/build/reproducible-path/xca-2.9.0 -isystem /usr/include/x86_64-linux-gnu/qt6/QtWidgets -isystem /usr/include/x86_64-linux-gnu/qt6 -isystem /usr/include/x86_64-linux-gnu/qt6/QtCore -isystem /usr/lib/x86_64-linux-gnu/qt6/mkspecs/linux-g++ -isystem /usr/include/x86_64-linux-gnu/qt6/QtGui -isystem /usr/include/x86_64-linux-gnu/qt6/QtSql -isystem /usr/include/x86_64-linux-gnu/qt6/QtHelp -g -O2 -ffile-prefix-map=/build/reproducible-path/xca-2.9.0=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -Wdate-time -D_FORTIFY_SOURCE=2 -std=gnu++17 -fPIC -Wall -Wextra -Wno-unknown-pragmas -fmacro-prefix-map=/build/reproducible-path/xca-2.9.0=. -MD -MT CMakeFiles/xcalib.dir/lib/pki_pkcs12.cpp.o -MF CMakeFiles/xcalib.dir/lib/pki_pkcs12.cpp.o.d -o CMakeFiles/xcalib.dir/lib/pki_pkcs12.cpp.o -c /build/reproducible-path/xca-2.9.0/lib/pki_pkcs12.cpp
| /build/reproducible-path/xca-2.9.0/lib/pki_pkcs12.cpp: In constructor ‘pki_pkcs12::pki_pkcs12(const QString&)’:
| /build/reproducible-path/xca-2.9.0/lib/pki_pkcs12.cpp:88:53: error: invalid conversion from ‘const unsigned char*’ to ‘unsigned char*’ [-fpermissive]
|    88 |                 unsigned char *str = X509_alias_get0(mycert, NULL);
|       |                                      ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
|       |                                                     |
|       |                                                     const unsigned char*
| make[4]: *** [CMakeFiles/xcalib.dir/build.make:215: CMakeFiles/xcalib.dir/lib/pki_pkcs12.cpp.o] Error 1

Full build log from the original reporter's build environment is attached here.

xca_2.9.0-1_amd64-2026-04-19T09_00_53Z.log