Config::IniFiles would definitely be my first choice for doing this effectively in production code.
Here is a map and regex solution to the same problem though.

#!/usr/local/bin/perl
use strict;

use Data::Dumper;

my %info = map { /^(\S+)\s*=\s*"?(.+?)"?$/ } <DATA>;

print Dumper( \%info );

__DATA__
key1="value1"
key2=value2
key3 = value3
key4 =value4
key5 = "value5"
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Wonko