In Update Manager's software sources, the option exists to choose a download server and protocol like shown below.
Do all updates download via HTTP only?
And if HTTPS (or SFTP) aren't supported, why does the option exist? Related question here, though it only deals with full ISO images.
Potentially yes the software showing the drop-down of protocols can support a https mirror - the drop-down box in question accepts the following valid protocols:
This is detailed in the software-properties-gtk package source code:
apt-get source software-properties-gtk
cd software-properties*/softwareproperties/gtk
Look in the file DialogMirror.py - function def is_valid_mirror
However in reality, the public mirrors Ubuntu supports is limited to http://, ftp:// & rsync://
The mirrors you can define is limited when you define a new mirror:
Therefore, since the software itself does not limit the protocols, one way to download over HTTPS is to define and maintain your own local repository & mirror. As usual we have a great Q&A that have several applicable answers:
apt-mirror is probably your best bet here. Install the apt-mirror package and examine its man page:
CONFIGURATION EXAMPLES
The mirror.list configuration supports many options...
HTTPS with sending Basic HTTP authentication information (plaintext username and password) for all
requests: (this was default behaviour of Wget 1.10.2 and prior and is needed for some servers with new
version of Wget) set auth_no_challenge 1 deb https://user:[email protected]:443/debian stable main contrib
non-free
HTTPS without checking certificate: set no_check_certificate 1 deb https://example.com:443/debian stable
main contrib non-free
As you can see, you can define a local HTTPS mirror - add your local HTTPS mirror and it should appear in the list of mirrors.
