I'm attempting to install the AWS IoT core on OpenWrt running atop a Raspberry Pi however the installation of cmake and libssl-dev is not going to plan
It seams you want to install Linux cmake software into openwrt device, openwrt can install special packages for openwrt only. Check the openwrt package lists.
I have found a page about packages, but how do I search them to discover which sources/repos, if any, have cmake and libssl-dev or their equivilancies?
Yes, that was the first thing I tried. With other Linux distributions I’ve used, I could usually add sources that contained the packages I wanted. Does OpenWrt not have this functionality?
If OpenWrt does not have this functionality, are there packages with other names in the OpenWrt repository that do the same things as cmake? What searchable documentation exists that I could look into to find out?
You have Linux PC, run Cmake on it, do not try to use OpenWrt to do that jobs.
OpenWrt is working on some wifi routers, maybe only 8MB rom and 64MB ram, no LCD, and CPU slower. But openwrt still could install GCC, Python, .... for some small programs.
My OpenWrt instance has 8GB of RAM and a four core CPU. It's a Raspberry Pi 4b. There should be some way to get this to work if I can learn to identify the correct processes to go by. Even if I have to refactor some code or substitute expressions.