On my machine at least man openssl shows that -k is for specifying the password you want to derive the key from, so in that case I think you are literally using the string /etc/ssl/private/etcBackup.key as the password. I think the flag you want is -kfile.
You can verify this by running the command in strace and seeing that there is no openat call for the file passed to -k.
Edit: metiulekm@sh.itjust.works beat me to it while I was writing out my answer :)
On my machine at least
man opensslshows that-kis for specifying the password you want to derive the key from, so in that case I think you are literally using the string/etc/ssl/private/etcBackup.keyas the password. I think the flag you want is-kfile.You can verify this by running the command in
straceand seeing that there is noopenatcall for the file passed to-k.Edit: metiulekm@sh.itjust.works beat me to it while I was writing out my answer :)