Description of problem:

Repositories (e.g: fedorapeople.org) allows authentication using the url based basic http auth:

"http://USER:PASS@repo_owner.fedorapeople.org/reponame/"

In the above format, on product -> new repository it is possible to specify credentials  that leads to an url of maximum 1024 chars length.

It is not usual to have long USER:PASS, however counting with the size of URL + reponame and specially if special chars are used in credentials.
(eg: username: 䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿 or username: Márçião) each char counts as 4 when quoted.

Example:

    >>> url_encode("䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿䑧㭿")
    >>> '%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF%E4%91%A7%E3%AD%BF'
    >>> # 252 chars


So to allow the use of special chars (eg: utf8) in credentials and avoid passing the limit of 1024 chars it would be a great idea to specify custom HTTP headers.

So encoding "username:password" as base64 will allow the use as headers

"Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ=="