discourse/lib/freedom_patches/rails_security_fixes.rb

module HTML
  class WhiteListSanitizer
      # Sanitizes a block of css code. Used by #sanitize when it comes across a style attribute
    def sanitize_css(style)
      # disallow urls
      style = style.to_s.gsub(/url\s*\(\s*[^\s)]+?\s*\)\s*/, ' ')

      # gauntlet
      if style !~ /\A([:,;#%.\sa-zA-Z0-9!]|\w-\w|\'[\s\w]+\'|\"[\s\w]+\"|\([\d,\s]+\))*\z/ ||
          style !~ /\A(\s*[-\w]+\s*:\s*[^:;]*(;|$)\s*)*\z/
        return ''
      end

      clean = []
      style.scan(/([-\w]+)\s*:\s*([^:;]*)/) do |prop,val|
        if allowed_css_properties.include?(prop.downcase)
          clean <<  prop + ': ' + val + ';'
        elsif shorthand_css_properties.include?(prop.split('-')[0].downcase)
          unless val.split().any? do |keyword|
            !allowed_css_keywords.include?(keyword) &&
              keyword !~ /\A(#[0-9a-f]+|rgb\(\d+%?,\d*%?,?\d*%?\)?|\d{0,2}\.?\d{0,2}(cm|em|ex|in|mm|pc|pt|px|%|,|\))?)\z/
          end
            clean << prop + ': ' + val + ';'
          end
        end
      end
      clean.join(' ')
    end
  end
end

module HTML
  class WhiteListSanitizer
    self.protocol_separator = /:|(&#0*58)|(&#x70)|(&#x0*3a)|(%|&#37;)3A/i

    def contains_bad_protocols?(attr_name, value)
      uri_attributes.include?(attr_name) &&
      (value =~ /(^[^\/:]*):|(&#0*58)|(&#x70)|(&#x0*3a)|(%|&#37;)3A/i && !allowed_protocols.include?(value.split(protocol_separator).first.downcase.strip))
    end
  end
end

module ActiveRecord
  class Relation

    def where_values_hash
      equalities = with_default_scope.where_values.grep(Arel::Nodes::Equality).find_all { |node|
        node.left.relation.name == table_name
      }

      Hash[equalities.map { |where| [where.left.name, where.right] }].with_indifferent_access
    end

  end
end

module ActiveRecord
  class PredicateBuilder # :nodoc:
    def self.build_from_hash(engine, attributes, default_table, allow_table_name = true)
      predicates = attributes.map do |column, value|
        table = default_table

        if allow_table_name && value.is_a?(Hash)
          table = Arel::Table.new(column, engine)

          if value.empty?
            '1 = 2'
          else
            build_from_hash(engine, value, table, false)
          end
        else
          column = column.to_s

          if allow_table_name && column.include?('.')
            table_name, column = column.split('.', 2)
            table = Arel::Table.new(table_name, engine)
          end

          attribute = table[column]

          case value
          when ActiveRecord::Relation
            value = value.select(value.klass.arel_table[value.klass.primary_key]) if value.select_values.empty?
            attribute.in(value.arel.ast)
          when Array, ActiveRecord::Associations::CollectionProxy
            values = value.to_a.map {|x| x.is_a?(ActiveRecord::Base) ? x.id : x}
            ranges, values = values.partition {|v| v.is_a?(Range) || v.is_a?(Arel::Relation)}

            array_predicates = ranges.map {|range| attribute.in(range)}

            if values.include?(nil)
              values = values.compact
              if values.empty?
                array_predicates << attribute.eq(nil)
              else
                array_predicates << attribute.in(values.compact).or(attribute.eq(nil))
              end
            else
              array_predicates << attribute.in(values)
            end

            array_predicates.inject {|composite, predicate| composite.or(predicate)}
          when Range, Arel::Relation
            attribute.in(value)
          when ActiveRecord::Base
            attribute.eq(value.id)
          when Class
            # FIXME: I think we need to deprecate this behavior
            attribute.eq(value.name)
          when Integer, ActiveSupport::Duration
            # Arel treats integers as literals, but they should be quoted when compared with strings
            column = engine.connection.schema_cache.columns_hash[table.name][attribute.name.to_s]
            attribute.eq(Arel::Nodes::SqlLiteral.new(engine.connection.quote(value, column)))
          else
            attribute.eq(value)
          end
        end
      end

      predicates.flatten
    end
  end
end