=begin
    Copyright 2010-2012 Tasos Laskos <tasos.laskos@gmail.com>

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
=end

require 'digest/md5'

#
# Logs all non 200 (OK) and non 404 server responses.
#
# @author Tasos "Zapotek" Laskos <tasos.laskos@gmail.com>
#
class Arachni::Modules::InterestingResponses < Arachni::Module::Base

    IGNORE_CODES = [ 200, 404 ].to_set
    MAX_ENTRIES  = 100

    def self.ran?
        @ran ||= false
    end

    def self.ran
        @ran = true
    end

    def self.counter
        @counter ||= 0
    end

    def self.counter=( int )
        @counter = int
    end

    def increment
        self.class.counter += 1
    end

    def limit_reached?
        self.class.counter >= MAX_ENTRIES
    end

    def run
        return if self.class.ran?

        # tell the HTTP interface to call this block every-time a request completes
        http.add_on_complete { |res| check_and_log( res ) }
    end

    def clean_up
        self.class.ran
    end

    def check_and_log( res )
        return if IGNORE_CODES.include?( res.code ) || res.body.to_s.empty? ||
            limit_reached?

        digest = Digest::MD5.hexdigest( res.body )
        path   = uri_parse( res.effective_url ).path

        return if audited?( path ) || audited?( digest )

        audited( path )
        audited( digest )
        increment

        log( { id: "Code: #{res.code}", element: Element::SERVER }, res )
        print_ok "Found an interesting response -- Code: #{res.code}."
    end

    def self.info
        {
            name:        'Interesting responses',
            description: %q{Logs all non 200 (OK) server responses.},
            elements:    [ Element::SERVER ],
            author:      'Tasos "Zapotek" Laskos <tasos.laskos@gmail.com>',
            version:     '0.1.4',
            targets:     %w(Generic),
            references:  {
                'w3.org' => 'http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html'
            },
            issue:       {
                name:        %q{Interesting server response.},
                description: %q{The server responded with a non 200 (OK) code. },
                tags:        %w(interesting response server),
                severity:    Severity::INFORMATIONAL
            }
        }
    end

    def self.acceptable
        [ 102, 200, 201, 202, 203, 206, 207, 208, 226, 300, 301, 302,
          303, 305, 306, 307, 308, 400, 401, 402, 403, 404, 405, 406, 407, 408, 409,
          410, 411, 412, 413, 414, 415, 416, 417, 418, 420, 422, 423, 424, 425, 426, 428,
          429, 431, 444, 449, 450, 451, 499, 500, 501, 502, 503, 504, 505, 506, 507, 508,
          509, 510, 511, 598, 599
        ]
    end

end