Question about download hooks

I’d like to implement two types of processing which require “hooking” downloads.

1) Enforce plugin + theme installs to a know list of allowed software.

2) Take over the download process, to unpack + scan any download + determine if the download will be allowed to continue or be stopped. For example, if malware is detected in a plugin or unacceptable language is embedded in image tags.

I’ve look through the codex and I’ve missed where these hooks are defined.

Someone please pass along a link to the Codex where these hooks are defined.

Thanks!