Authen::Simple::DBI - Simple DBI authentication

    use Authen::Simple::DBI;

    my $dbi = Authen::Simple::DBI->new(
        dsn       => 'dbi:SQLite:dbname=database.db',
        statement => 'SELECT password FROM users WHERE username = ?'
    );

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

    # or as a mod_perl Authen handler

    PerlModule Apache::DBI
    PerlModule Authen::Simple::Apache
    PerlModule Authen::Simple::DBI

    PerlSetVar AuthenSimpleDBI_dsn       "dbi:SQLite:dbname=database.db"
    PerlSetVar AuthenSimpleDBI_statement "SELECT password FROM users WHERE username = ?"

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

package Authen::Simple::DBI;

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

use DBI              qw[SQL_CHAR];
use Params::Validate qw[];

our $VERSION = 0.2;

__PACKAGE__->options({
    dsn => {
        type     => Params::Validate::SCALAR,
        optional => 0
    },
    statement => {
        type     => Params::Validate::SCALAR,
        optional => 0
    },
    username => {
        type     => Params::Validate::SCALAR,
        optional => 1
    },
    password => {
        type     => Params::Validate::SCALAR,
        optional => 1
    },
    attributes => { # undocumented for now
        type     => Params::Validate::HASHREF,
        default  => { ChopBlanks => 1, PrintError => 0, RaiseError => 0 },
        optional => 1
    }
});

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

    my ( $dsn, $dbh, $sth, $encrypted ) = ( $self->dsn, undef, undef, undef );

    unless ( $dbh = DBI->connect_cached( $dsn, $self->username, $self->password, $self->attributes ) ) {

        my $error = DBI->errstr;

        $self->log->error( qq/Failed to connect to database using dsn '$dsn'. Reason: '$error'/ )
          if $self->log;

        return 0;
    }

    unless ( $sth = $dbh->prepare_cached( $self->statement ) ) {

        my $error     = $dbh->errstr;
        my $statement = $self->statement;

        $self->log->error( qq/Failed to prepare statement '$statement'. Reason: '$error'/ )
          if $self->log;

        return 0;
    }

    unless ( $sth->bind_param( 1, $username, SQL_CHAR ) ) {

        my $error     = $sth->errstr;
        my $statement = $self->statement;

        $self->log->error( qq/Failed to bind param '$username' to statement '$statement'. Reason: '$error'/ )
          if $self->log;

        return 0;
    }

    unless ( $sth->execute ) {

        my $error     = $sth->errstr;
        my $statement = $self->statement;

        $self->log->error( qq/Failed to execute statement '$statement'. Reason: '$error'/ )
          if $self->log;

        return 0;
    }

    unless ( $sth->bind_col( 1, \$encrypted ) ) {

        my $error     = $sth->errstr;
        my $statement = $self->statement;

        $self->log->error( qq/Failed to bind column. Reason: '$error'/ )
          if $self->log;

        return 0;
    }

    unless ( $sth->fetch ) {

        my $statement = $self->statement;

        $self->log->debug( qq/User '$username' was not found with statement '$statement'./ )
          if $self->log;

        return 0;
    }

    $sth->finish;

    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__