Class: Scryer::Rules::WeakSessionCookieRule

Inherits:
Scryer::Rule show all
Defined in:
lib/scryer/rules/weak_session_cookie_rule.rb

Overview

Flags config.session_store :cookie_store, ... with no secure: true in its options — without it, the session cookie can be sent over plain HTTP, not just HTTPS. Only :cookie_store is checked (the default and most common store); other stores (:redis_session_store, ...) don't carry the same cookie-content risk and are out of scope here.

Instance Attribute Summary

Attributes inherited from Scryer::Rule

#file, #sexp, #source

Instance Method Summary collapse

Methods inherited from Scryer::Rule

inherited, #initialize

Constructor Details

This class inherits a constructor from Scryer::Rule

Instance Method Details

#scan ⇒ Object 



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# File 'lib/scryer/rules/weak_session_cookie_rule.rb', line 14

def scan
  findings = []

  Ast.each_node(sexp) do |node|
    next unless Ast.tagged?(node, :command, :command_call, :method_add_arg)

    inner = Ast.tagged?(node, :method_add_arg) ? node[1] : node
    receiver_and_name = Ast.call_name(inner)
    next unless receiver_and_name

    _receiver, method_name = receiver_and_name
    next unless method_name == "session_store"

    args = Ast.call_arguments(node)
    next unless args.any? { |a| Ast.literal_text(a) == "cookie_store" }
    next if Ast.true_literal?(Ast.keyword_arg(args, "secure"))

    line = Ast.line_of(node)
    findings << finding(
      line: line,
      message: "`session_store :cookie_store` has no `secure: true` — the session cookie " \
                "can be transmitted over plain HTTP, where it's exposed to network " \
                "eavesdropping (e.g. on shared/untrusted Wi-Fi).",
      suggested_fix: "Add `secure: true` to the session_store options (typically only in " \
                      "production, since local HTTP development doesn't have TLS): " \
                      "`config.session_store :cookie_store, key: '_app_session', secure: " \
                      "Rails.env.production?`."
    )
  end

  findings
end