Authen::Simple::DBM - Simple DBM authentication

    use Authen::Simple::DBM;

    my $dbm = Authen::Simple::DBM->new(
        path => '/var/db/www/passwd'
    );

    if ( $dbm->authenticate( $username, $password ) ) {
        # successfull authentication
    }

    # or as a mod_perl Authen handler

    PerlModule Authen::Simple::Apache
    PerlModule Authen::Simple::DBM

    PerlSetVar AuthenSimpleDBM_path "/var/db/www/passwd"

    <Location /protected>
      PerlAuthenHandler Authen::Simple::DBM
      AuthType          Basic
      AuthName          "Protected Area"
      Require           valid-user
    </Location>

package Authen::Simple::DBM;

use strict;
use warnings;
use base 'Authen::Simple::Adapter';

use Carp             qw[];
use Fcntl            qw[];
use Params::Validate qw[];

our $VERSION = 0.2;

__PACKAGE__->options({
    path => {
        type      => Params::Validate::SCALAR,
        optional  => 0
    },
    type => {
        type      => Params::Validate::SCALAR,
        default   => 'SDBM',
        optional  => 1,
        callbacks => {
            'is either DB, GDBM, NDBM or SDBM' => sub {
                $_[0] =~ qr/^CDB|DB|GDBM|NDBM|SDBM$/;
            }
        }
    }
});

sub init {
    my ( $self, $params ) = @_;

    my $type  = $params->{type};
    my $path  = $params->{path};
    my $class = sprintf( '%s_File', $type );

    unless ( -e $path || -e "$path.db" || -e "$path.pag" ) {
        Carp::croak( qq/Database path '$path' does not exist./ );
    }

    unless ( -f _ ) {
        Carp::croak( qq/Database path '$path' is not a file./ );
    }

    unless ( -r _ ) {
        Carp::croak( qq/Database path '$path' is not readable by effective uid '$>'./ );
    }

    unless ( eval "require $class;" ) {
        Carp::croak( qq/Failed to load class '$class' for DBM type '$type'. Reason: '$@'/ );
    }

    my $dbm = $self->_open_dbm( $type, $path )
      or Carp::croak( qq/Failed to open database '$path'. Reason: '$!'/ );

    return $self->SUPER::init($params);
}

sub _open_dbm {
    my $self  = shift;
    my $type  = shift || $self->type;
    my $path  = shift || $self->path;

    my $flags = $type eq 'GDBM' ? &GDBM_File::GDBM_READER : &Fcntl::O_RDONLY;
    my $class = sprintf( '%s_File', $type );
    my @args  = ( $path );

    unless ( $type eq 'CDB' ) {
        push( @args, $flags, 0644 );
    }

    return $class->TIEHASH(@args);
}

sub check {
    my ( $self, $username, $password ) = @_;

    my ( $path, $dbm, $encrypted ) = ( $self->path, undef, undef );

    unless ( $dbm = $self->_open_dbm ) {

        $self->log->error( qq/Failed to open database '$path'. Reason: '$!'/ )
          if $self->log;

        return 0;
    }

    unless (    defined( $encrypted = $dbm->FETCH( $username        ) )
             || defined( $encrypted = $dbm->FETCH( $username . "\0" ) ) ) {

        $self->log->debug( qq/User '$username' was not found in database '$path'./ )
          if $self->log;

        return 0;
    }

    chop($encrypted) if substr( $encrypted, -1 ) eq "\0";

    $encrypted = ( split( ':', $encrypted, 3 ) )[0];

    unless ( defined $encrypted && length $encrypted ) {

        $self->log->debug( qq/Encrypted password for user '$username' is null./ )
          if $self->log;

        return 0;
    }

    unless ( $self->check_password( $password, $encrypted ) ) {

        $self->log->debug( qq/Failed to authenticate user '$username'. Reason: 'Invalid credentials'/ )
          if $self->log;

        return 0;
    }

    $self->log->debug( qq/Successfully authenticated user '$username'./ )
      if $self->log;

    return 1;
}

1;

__END__