write to svn via https and ssh, svn server with one operating system user for ssh access

[rupert.thurner]

hi,

i tried to search a little but i did not see it explicitely:

1. is it possible to access the same svn repository for writing via
http(s) and ssh?
2. how would it be possible to configure svn so that only one
operating system user is needed for ssh access, like e.g. github is
doing?

rupert.