First, we need to get the GPG key used by external repositories and some DEB files.
mkdir ./trust
dlkey() { wget -q -O - --https-only --secure-protocol=TLSv1_2 -- "$1" | gpg --dearmor | base64; }
dlkey 'https://keyserver.ubuntu.com/pks/lookup?op=get&search=0xEB8B81E14DA65431D7504EA8F63F0F2B90935439' >./trust/ppa_kisak.txt
dlkey 'https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x2388FF3BE10A76F638F80723FCAE110B1118213C' >./trust/ppa_graphics_drivers.txt
dlkey 'https://dl.winehq.org/wine-builds/winehq.key' >./trust/winehq.txt
dlkey 'https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x82D96E430A1F1C0F0502747E37B90EDD4E3EFAE4' >./trust/ppa_lutris.txt
dlkey 'https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x824A27DD09DEDA33BF7835962EA8F35793D8809A' >./trust/ppa_flexiondotorg.txt
(cd ./trust && wget http://security.ubuntu.com/ubuntu/pool/main/o/openssl/libssl1.1_1.1.1f-1ubuntu2.16_amd64.deb http://security.ubuntu.com/ubuntu/pool/main/o/openssl/libssl1.1_1.1.1f-1ubuntu2.16_i386.deb)