#
# random_norwegian_ssn()
#
# Accepts one parameter, a date string in the format DDMMYY.
#
sub random_norwegian_ssn {
    my $date = shift;

    # Extract date, month, year
    my $d1 = substr($date,0,1);
    my $d2 = substr($date,1,1);
    my $m1 = substr($date,2,1);
    my $m2 = substr($date,3,1);
    my $y1 = substr($date,4,1);
    my $y2 = substr($date,5,1);

    my ($i1, $i2, $i3);
    my ($c1, $c2);

    do {
        # SSNs for dates between 1900-1999 use an entity number between 0-499
        my $random_num = int(rand(499));

        # Pad the entity number to 3 numbers
        my $padded_num = sprintf("%03d", $random_num);
        ($i1, $i2, $i3) = split(//, $padded_num);

        # Calculate the two control numbers
        my $v1 = (3*$d1) + (7*$d2) + (6*$m1) + $m2 + (8*$y1) + (9*$y2) + (4*$i1) + (5*$i2) + (2*$i3);
        $c1 = ($v1 % 11) == 0 ? 0 : 11-($v1 % 11);

        my $v2 = (5*$d1) + (4*$d2) + (3*$m1) + (2*$m2) + (7*$y1) + (6*$y2) + (5*$i1) +(4*$i2) + (3*$i3) + (2*$c1);
        $c2 = ($v2 % 11) == 0 ? 0 : 11-($v2 % 11);

    } until ($c1 < 10 && $c2 < 10);

    return "$d1$d2$m1$m2$y1$y2$i1$i2$i3$c1$c2";
}

#
# random_norwegian_ssn()
#
# Accepts a date parameter, in the format DDMMYY.
#
sub random_norwegian_ssn {
    my $date = shift;

    # Extract date, month, year
    my $d1 = substr($date,0,1);
    my $d2 = substr($date,1,1);
    my $m1 = substr($date,2,1);
    my $m2 = substr($date,3,1);
    my $y1 = substr($date,4,1);
    my $y2 = substr($date,5,1);

    my ($i1, $i2, $i3);
    my ($c1, $c2);

    do {
        # SSNs for dates between 1900-1999 use an entity number between 0-499
        my $random_num = int(rand(499));

        # Pad the entity number to 3 numbers
        my $padded_num = sprintf("%03d", $random_num);
        ($i1, $i2, $i3) = split(//, $padded_num);

        # Calculate the two control numbers
        my $v1 = (3*$d1) + (7*$d2) + (6*$m1) + $m2 + (8*$y1) + (9*$y2) + (4*$i1) + (5*$i2) + (2*$i3);
        $c1 = ($v1 % 11) == 0 ? 0 : 11-($v1 % 11);

        my $v2 = (5*$d1) + (4*$d2) + (3*$m1) + (2*$m2) + (7*$y1) + (6*$y2) + (5*$i1) +(4*$i2) + (3*$i3) + (2*$c1);
        $c2 = ($v2 % 11) == 0 ? 0 : 11-($v2 % 11);

    } until ($c1 < 10 && $c2 < 10);

    return "$d1$d2$m1$m2$y1$y2$i1$i2$i3$c1$c2";
}

Generates a random valid norwegian SSN for dates between 1900 and 1999

Generate random valid norwegian SSN

Perl