comupte: Sanity check the provided public key
comupte: Sanity check the provided public key

Check that it contains at least two whitespace separated tokens and remove any
leading/trailing whitespaces and line breaks.

Signed-off-by: Juerg Haefliger <959025bf4358c56e5f77d423544af56ce4c33875@gmail.com>

dtroyer/dwarf,juergh/dwarf,dtroyer/dwarf,juergh/dwarf