Module: Aikido::Zen::Sinks::Curl::Extensions

Defined in:
lib/aikido/zen/sinks/curb.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.wrap_request(curl, url: curl.url) ⇒ Object 



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# File 'lib/aikido/zen/sinks/curb.rb', line 15

def self.wrap_request(curl, url: curl.url)
  Aikido::Zen::Scanners::SSRFScanner::Request.new(
    verb: nil, # Curb hides this by directly setting an option in C
    uri: URI(url),
    headers: curl.headers
  )
end

.wrap_response(curl) ⇒ Object 



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# File 'lib/aikido/zen/sinks/curb.rb', line 23

def self.wrap_response(curl)
  # Curb made an… interesting choice by not parsing the response headers
  # and forcing users to do this manually if they need to look at them.
  _, *headers = curl.header_str.split(/[\r\n]+/).map(&:strip)
  headers = headers.flat_map { |str| str.scan(/\A(\S+): (.+)\z/) }.to_h

  if curl.url != curl.last_effective_url
    status = 302 # We can't know what the original status was, but we just need a 3XX
    headers["Location"] = curl.last_effective_url
  else
    status = curl.status.to_i
  end

  Aikido::Zen::Scanners::SSRFScanner::Response.new(status: status, headers: headers)
end

Instance Method Details

#perform ⇒ Object 



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# File 'lib/aikido/zen/sinks/curb.rb', line 39

def perform
  wrapped_request = Extensions.wrap_request(self)

  # Store the request information so the DNS sinks can pick it up.
  if (context = Aikido::Zen.current_context)
    prev_request = context["ssrf.request"]
    context["ssrf.request"] = wrapped_request
  end

  SINK.scan(
    connection: Aikido::Zen::OutboundConnection.from_uri(URI(url)),
    request: wrapped_request,
    operation: "request"
  )

  response = super

  Aikido::Zen::Scanners::SSRFScanner.track_redirects(
    request: wrapped_request,
    response: Extensions.wrap_response(self)
  )

  # When libcurl has follow_location set, it will handle redirections
  # internally, and expose the "last_effective_url" as the URI that was
  # last requested in the redirect chain.
  #
  # In this case, we can't actually stop the request from happening, but
  # we can scan again (now that we know another request happened), to
  # stop the response from being exposed to the user. This downgrades
  # the SSRF into a blind SSRF, which is better than doing nothing.
  if url != last_effective_url
    last_effective_request = Extensions.wrap_request(self, url: last_effective_url)
    context["ssrf.request"] = last_effective_request if context

    SINK.scan(
      connection: Aikido::Zen::OutboundConnection.from_uri(URI(last_effective_url)),
      request: last_effective_request,
      operation: "request"
    )
  end

  response
ensure
  context["ssrf.request"] = prev_request if context
end