The official way to download the Canon EOS Digital SDK is through the Canon Developer Programme
However, for greenfield development or modern cameras, you are strongly advised to use the latest Canon EOS SDK or open-source alternatives like gPhoto2. Version 3.5 should be seen as a historical tool—not a future-proof solution. canon eos digital info sdk 3.5 download
Official EDSDK: Current versions (e.g., v13.19.0) are for building custom apps to control cameras via USB. The official way to download the Canon EOS
Downloading and Using the Canon EOS Digital Info SDK 3.5 Note: Canon often updates the version numbers
https://developercommunity.usa.canon.comhttp://gphoto.org/doc/https://www.dpreview.com/forums/1037Wayback Machine (archive.org) – Snapshots of Canon’s software.canon-europe.com from 2012
Owner/Artist/Copyright Strings: Fields that can be edited and saved directly back to the camera. 2. The Role of SDK 3.5