Authen::Simple::Passwd - Simple Passwd authentication

    use Authen::Simple::Passwd;

    my $passwd = Authen::Simple::Passwd->new( 
        path => '/etc/passwd'
    );

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

    # or as a mod_perl Authen handler

    PerlModule Authen::Simple::Apache
    PerlModule Authen::Simple::Passwd

    PerlSetVar AuthenSimplePasswd_path "/etc/passwd"

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

package Authen::Simple::Passwd;

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

use Carp             qw[];
use Config           qw[];
use Fcntl            qw[LOCK_SH];
use IO::File         qw[O_RDONLY];
use Params::Validate qw[];

our $VERSION = 0.6;

__PACKAGE__->options({
    path => {
        type      => Params::Validate::SCALAR,
        optional  => 1
    },
    flock => {
        type      => Params::Validate::SCALAR,
        default   => ( $Config::Config{d_flock} ) ? 1 : 0,
        optional  => 1
    },
    passwd => {  # deprecated
        type      => Params::Validate::SCALAR,
        optional  => 1
    },
    allow => {   # deprecated
        type      => Params::Validate::ARRAYREF,
        optional  => 1,
    }
});

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

    my $path = $params->{path} ||= delete $params->{passwd};

    unless ( -e $path ) {
        Carp::croak( qq/Passwd path '$path' does not exist./ );
    }

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

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

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

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

    if ( $username =~ /^-/ ) {

        $self->log->debug( qq/User '$username' begins with a hyphen which is not allowed./ )
          if $self->log;

        return 0;
    }

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

    unless ( $fh = IO::File->new( $path, O_RDONLY ) ) {

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

        return 0;
    }

    unless ( !$self->flock || flock( $fh, LOCK_SH ) ) {

        $self->log->error( qq/Failed to obtain a shared lock on passwd '$path'. Reason: '$!'/ )
          if $self->log;

        return 0;
    }

    while ( defined( $_ = $fh->getline ) ) {

        next if /^#/;
        next if /^\s+/;

        chop;

        my (@credentials) = split( /:/, $_, 3 );

        if ( $credentials[0] eq $username ) {

            $encrypted = $credentials[1];

            $self->log->debug( qq/Found user '$username' in passwd '$path'./ )
              if $self->log;

            last;
        }
    }

    unless ( $fh->close ) {

        $self->log->warn( qq/Failed to close passwd '$path'. Reason: '$!'/ )
          if $self->log;
    }

    unless ( defined $encrypted ) {

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

        return 0;
    }

    unless ( 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__