surprised no one has mentioned dropbear yet. i don't remember the name off the top of my head, but there's a relatively easy way to setup your initramfs to listen for SSH connections, authenticate with a private key, and send the unlock key. bonus points for writing a script to do it automatically with cute names, e.g. "sendkey helium.intra" or whatever
matrix. it's not perfect, but it's the least shit option i've found so far. in the poorly paraphrased words of bjarne stroustrup, "there are only two kinds of chat protocols: the ones people complain about, and the ones nobody uses"
if i suggested encrypting said files before uploading them to cloud storage, would that be good advice or ramblings-of-the-homeless-man-on-the-corner-warning-of-the-black-helicopters
surprised no one has mentioned dropbear yet. i don't remember the name off the top of my head, but there's a relatively easy way to setup your initramfs to listen for SSH connections, authenticate with a private key, and send the unlock key. bonus points for writing a script to do it automatically with cute names, e.g. "sendkey helium.intra" or whatever