If 'strip spaces' simply means to remove all spaces, here's one approach:

>perl -wMstrict -le
"use Data::Dumper;
 my %hash = (
   ' k 1 ' => ' v 1 ',
   ' k 2 ' => ' v 2 ',
   );
 print Dumper \%hash;
 %hash = map { s{\s+}{}xmsg;  $_ } %hash;
 print Dumper \%hash;
"
$VAR1 = {
          ' k 2 ' => ' v 2 ',
          ' k 1 ' => ' v 1 '
        };

$VAR1 = {
          'k2' => 'v2',
          'k1' => 'v1'
        };
[download]

Beware, however, that if the original hash has a key  ' k e y ' and also another key  'key', something is going to get clobbered.

Update: Per ikegami's reply Re^2: Strip spaces in hash, I would add the cautionary note that, had the output of map not ultimately been assigned to the source hash in the code above, the values of that hash would, as a side effect, and perhaps quite unexpectedly and mysteriously, have been altered. Many happy hours of debugging ensue.