Class: FinalDestination
- Inherits:
-
Object
- Object
- FinalDestination
- Defined in:
- lib/final_destination.rb,
lib/final_destination/ssrf_detector.rb,
lib/final_destination/faraday_adapter.rb
Overview
Determine the final endpoint for a Web URI, following redirects
Defined Under Namespace
Modules: SSRFDetector Classes: FaradayAdapter, HTTP, Resolver, SSRFError, UrlEncodingError
Constant Summary collapse
- MAX_REQUEST_TIME_SECONDS =
10
- MAX_REQUEST_SIZE_BYTES =
1024 * 1024 * 5
5_242_880
- DEFAULT_USER_AGENT =
"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0 Safari/605.1.15"
Instance Attribute Summary collapse
-
#content_type ⇒ Object
readonly
Returns the value of attribute content_type.
-
#cookie ⇒ Object
readonly
Returns the value of attribute cookie.
-
#ignored ⇒ Object
readonly
Returns the value of attribute ignored.
-
#status ⇒ Object
readonly
Returns the value of attribute status.
-
#status_code ⇒ Object
readonly
Returns the value of attribute status_code.
Class Method Summary collapse
- .cache_https_domain(domain) ⇒ Object
- .clear_https_cache!(domain) ⇒ Object
- .connection_timeout ⇒ Object
- .is_https_domain?(domain) ⇒ Boolean
- .redis_https_key(domain) ⇒ Object
- .resolve(url, opts = nil) ⇒ Object
Instance Method Summary collapse
-
#get(redirects = @limit, extra_headers: {}, except_headers: [], &blk) ⇒ Object
this is a new interface for simply getting N bytes accounting for all internal logic.
- #hostname ⇒ Object
- #hostname_matches?(url) ⇒ Boolean
- #hostname_matches_s3_endpoint?(allowed_internal_host) ⇒ Boolean
- #http_port_ok? ⇒ Boolean
- #http_verb(force_get_hosts, follow_canonical) ⇒ Object
-
#initialize(url, opts = nil) ⇒ FinalDestination
constructor
A new instance of FinalDestination.
- #log(log_level, message) ⇒ Object
- #normalized_url ⇒ Object
- #redirected? ⇒ Boolean
- #request_headers ⇒ Object
- #resolve ⇒ Object
- #skip_validations? ⇒ Boolean
- #small_get(request_headers) ⇒ Object
- #timeout ⇒ Object
- #validate_uri ⇒ Object
- #validate_uri_format ⇒ Object
Constructor Details
#initialize(url, opts = nil) ⇒ FinalDestination
Returns a new instance of FinalDestination.
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# File 'lib/final_destination.rb', line 44 def initialize(url, opts = nil) @url = url @uri = uri(normalized_url) if @url @opts = opts || {} @force_get_hosts = @opts[:force_get_hosts] || [] @preserve_fragment_url_hosts = @opts[:preserve_fragment_url_hosts] || [] @force_custom_user_agent_hosts = @opts[:force_custom_user_agent_hosts] || [] @default_user_agent = @opts[:default_user_agent] || DEFAULT_USER_AGENT @opts[:max_redirects] ||= 5 @https_redirect_ignore_limit = @opts[:initial_https_redirect_ignore_limit] @include_port_in_host_header = @opts[:include_port_in_host_header] || false @max_redirects = @opts[:max_redirects] @limit = @max_redirects @ignored = [] if @limit > 0 ignore_redirects = [Discourse.base_url_no_prefix] ignore_redirects.concat(@opts[:ignore_redirects]) if @opts[:ignore_redirects] ignore_redirects.each do |ignore_redirect| ignore_redirect = uri(ignore_redirect) @ignored << ignore_redirect.hostname if ignore_redirect.present? && ignore_redirect.hostname end end @status = :ready @follow_canonical = @opts[:follow_canonical] @http_verb = @opts[:http_verb] || http_verb(@force_get_hosts, @follow_canonical) @cookie = nil @limited_ips = [] @verbose = @opts[:verbose] || false @timeout = @opts[:timeout] || nil @preserve_fragment_url = @preserve_fragment_url_hosts.any? { |host| hostname_matches?(host) } @validate_uri = @opts.fetch(:validate_uri) { true } @user_agent = ( if @force_custom_user_agent_hosts.any? { |host| hostname_matches?(host) } Onebox::Helpers.user_agent else @default_user_agent end ) @stop_at_blocked_pages = @opts[:stop_at_blocked_pages] @extra_headers = @opts[:headers] end |
Instance Attribute Details
#content_type ⇒ Object (readonly)
Returns the value of attribute content_type.
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# File 'lib/final_destination.rb', line 42 def content_type @content_type end |
#cookie ⇒ Object (readonly)
Returns the value of attribute cookie.
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# File 'lib/final_destination.rb', line 42 def @cookie end |
#ignored ⇒ Object (readonly)
Returns the value of attribute ignored.
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# File 'lib/final_destination.rb', line 42 def ignored @ignored end |
#status ⇒ Object (readonly)
Returns the value of attribute status.
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# File 'lib/final_destination.rb', line 42 def status @status end |
#status_code ⇒ Object (readonly)
Returns the value of attribute status_code.
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# File 'lib/final_destination.rb', line 42 def status_code @status_code end |
Class Method Details
.cache_https_domain(domain) ⇒ Object
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# File 'lib/final_destination.rb', line 25 def self.cache_https_domain(domain) key = redis_https_key(domain) Discourse.redis.without_namespace.setex(key, 1.day.to_i, "1") end |
.clear_https_cache!(domain) ⇒ Object
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# File 'lib/final_destination.rb', line 20 def self.clear_https_cache!(domain) key = redis_https_key(domain) Discourse.redis.without_namespace.del(key) end |
.connection_timeout ⇒ Object
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# File 'lib/final_destination.rb', line 93 def self.connection_timeout 20 end |
.is_https_domain?(domain) ⇒ Boolean
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# File 'lib/final_destination.rb', line 30 def self.is_https_domain?(domain) key = redis_https_key(domain) Discourse.redis.without_namespace.get(key).present? end |
.redis_https_key(domain) ⇒ Object
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# File 'lib/final_destination.rb', line 35 def self.redis_https_key(domain) "HTTPS_DOMAIN_#{domain}" end |
.resolve(url, opts = nil) ⇒ Object
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# File 'lib/final_destination.rb', line 97 def self.resolve(url, opts = nil) new(url, opts).resolve end |
Instance Method Details
#get(redirects = @limit, extra_headers: {}, except_headers: [], &blk) ⇒ Object
this is a new interface for simply getting N bytes accounting for all internal logic
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# File 'lib/final_destination.rb', line 159 def get(redirects = @limit, extra_headers: {}, except_headers: [], &blk) raise "Must specify block" unless block_given? if @uri && @uri.port == 80 && FinalDestination.is_https_domain?(@uri.hostname) @uri.scheme = "https" @uri = URI(@uri.to_s) end return if !validate_uri return if @stop_at_blocked_pages && blocked_domain?(@uri) result, headers_subset = safe_get(@uri, except_headers:, &blk) return if !result = headers_subset. location = headers_subset.location if result == :redirect return if !location old_uri = @uri location = "#{@uri.scheme}://#{@uri.host}#{location}" if location[0] == "/" @uri = uri(location) if @uri && redirects == @max_redirects && @https_redirect_ignore_limit && same_uri_but_https?(old_uri, @uri) redirects += 1 @https_redirect_ignore_limit = false end return if redirects == 0 # https redirect, so just cache that whole new domain is https if old_uri.port == 80 && @uri&.port == 443 && (URI::HTTPS === @uri) FinalDestination.cache_https_domain(@uri.hostname) end return if !@uri extra = nil extra = { "Cookie" => } if # Most HTTP Clients strip the Authorization header on redirects as the client could be redirecting to a untrusted # party. Not stripping the Authorization header on redirect can also lead to problems where the # redirected party does not expect a Authorization header and thus rejects the request. except_headers = ["Authorization"] get(redirects - 1, extra_headers: extra, except_headers:, &blk) elsif result == :ok @uri.to_s else nil end end |
#hostname ⇒ Object
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# File 'lib/final_destination.rb', line 449 def hostname @uri.hostname end |
#hostname_matches?(url) ⇒ Boolean
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# File 'lib/final_destination.rb', line 453 def hostname_matches?(url) url = uri(url) if @uri&.hostname.present? && url&.hostname.present? hostname_parts = url.hostname.split(".") has_wildcard = hostname_parts.first == "*" if has_wildcard @uri.hostname.end_with?(hostname_parts[1..-1].join(".")) else @uri.hostname == url.hostname end end end |
#hostname_matches_s3_endpoint?(allowed_internal_host) ⇒ Boolean
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# File 'lib/final_destination.rb', line 443 def hostname_matches_s3_endpoint?(allowed_internal_host) s3_endpoint_uri = URI(SiteSetting.s3_endpoint) hostname_matches?("http://#{allowed_internal_host}") && @uri.port == s3_endpoint_uri.port && @uri.hostname.end_with?(s3_endpoint_uri.hostname) end |
#http_port_ok? ⇒ Boolean
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# File 'lib/final_destination.rb', line 432 def http_port_ok? return true if @uri.port == 80 allowed_internal_hosts = SiteSetting.allowed_internal_hosts&.split(/[|\n]/)&.filter_map { |aih| aih.strip.presence } return false if allowed_internal_hosts.empty? || SiteSetting.s3_endpoint.blank? return false if allowed_internal_hosts.none? { |aih| hostname_matches_s3_endpoint?(aih) } true end |
#http_verb(force_get_hosts, follow_canonical) ⇒ Object
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# File 'lib/final_destination.rb', line 101 def http_verb(force_get_hosts, follow_canonical) if follow_canonical || force_get_hosts.any? { |host| hostname_matches?(host) } :get else :head end end |
#log(log_level, message) ⇒ Object
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# File 'lib/final_destination.rb', line 474 def log(log_level, ) return unless @verbose return if @status_code == 404 Rails.logger.public_send( log_level, "#{RailsMultisite::ConnectionManagement.current_db}: #{}", ) end |
#normalized_url ⇒ Object
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# File 'lib/final_destination.rb', line 468 def normalized_url UrlHelper.normalized_encode(@url) rescue ArgumentError => e raise UrlEncodingError, e. end |
#redirected? ⇒ Boolean
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# File 'lib/final_destination.rb', line 113 def redirected? @limit < @max_redirects end |
#request_headers ⇒ Object
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# File 'lib/final_destination.rb', line 117 def request_headers result = { "User-Agent" => @user_agent, "Accept" => "*/*", "Accept-Language" => "*", "Host" => @uri.hostname + (@include_port_in_host_header ? ":#{@uri.port}" : ""), } result.merge!(@extra_headers) if @extra_headers result["Cookie"] = @cookie if @cookie result end |
#resolve ⇒ Object
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# File 'lib/final_destination.rb', line 214 def resolve if @uri && @uri.port == 80 && FinalDestination.is_https_domain?(@uri.hostname) @uri.scheme = "https" @uri = URI(@uri.to_s) end if @limit < 0 @status = :too_many_redirects log(:warn, "FinalDestination could not resolve URL (too many redirects): #{@uri}") return end unless validate_uri @status = :invalid_address log(:warn, "FinalDestination could not resolve URL (invalid URI): #{@uri}") return end @ignored.each do |host| if @uri&.hostname&.match?(host) @status = :resolved return @uri end end if Oneboxer.cached_response_body_exists?(@uri.to_s) @status = :resolved return @uri end headers = request_headers middlewares = Excon.defaults[:middlewares].dup middlewares << Excon::Middleware::Decompress if @http_verb == :get request_start_time = Time.now response_body = +"" request_validator = lambda do |chunk, _remaining_bytes, _total_bytes| response_body << chunk if response_body.bytesize > MAX_REQUEST_SIZE_BYTES raise Excon::Errors::ExpectationFailed.new("response size too big: #{@uri}") end if Time.now - request_start_time > MAX_REQUEST_TIME_SECONDS raise Excon::Errors::ExpectationFailed.new("connect timeout reached: #{@uri}") end end # This technique will only use the first resolved IP # TODO: Can we standardise this by using FinalDestination::HTTP? begin resolved_ip = SSRFDetector.lookup_and_filter_ips(@uri.hostname).first rescue SSRFDetector::DisallowedIpError, SocketError, Timeout::Error @status = :invalid_address return end request_uri = @uri.dup request_uri.hostname = resolved_ip unless Rails.env.test? # WebMock doesn't understand the IP-based requests response = Excon.public_send( @http_verb, request_uri.to_s, read_timeout: timeout, connect_timeout: timeout, headers: { "Host" => @uri.hostname }.merge(headers), middlewares: middlewares, response_block: request_validator, ssl_verify_peer_host: @uri.hostname, ) if @stop_at_blocked_pages if blocked_domain?(@uri) || response.headers["Discourse-No-Onebox"] == "1" @status = :blocked_page return end end location = nil response_headers = nil response_status = response.status.to_i case response.status when 200 # Cache body of successful `get` requests if @http_verb == :get if Oneboxer.cache_response_body?(@uri) Oneboxer.cache_response_body(@uri.to_s, response_body) end end if @follow_canonical next_url = fetch_canonical_url(response_body) if next_url.to_s.present? && next_url != @uri @follow_canonical = false @uri = next_url @http_verb = http_verb(@force_get_hosts, @follow_canonical) return resolve end end @content_type = response.headers["Content-Type"] if response.headers.has_key?("Content-Type") @status = :resolved return @uri when 103, 400, 405, 406, 409, 500, 501 response_status, small_headers = small_get(request_headers) if @stop_at_blocked_pages # this may seem weird, but the #to_hash method of the response object # of ruby's net/http lib returns a hash where each value is an array. # small_headers here is like that so our no onebox header value is an # array if it's set. Also the hash keys are always lower-cased. dont_onebox = small_headers["discourse-no-onebox"]&.join("") == "1" if dont_onebox || blocked_domain?(@uri) @status = :blocked_page return end end if response_status == 200 @status = :resolved return @uri end response_headers = {} if = small_headers["set-cookie"] response_headers[:cookies] = end if location_val = small_headers["location"] response_headers[:location] = location_val.join end end unless response_headers response_headers = { cookies: response.data[:cookies] || response.headers[:"set-cookie"], location: response.headers[:location], } end location = response_headers[:location] if (300..399).include?(response_status) if = response_headers[:cookies] @cookie = Array.wrap().map { |c| c.split(";").first.strip }.join("; ") end if location redirect_uri = uri(location) if @uri.host == redirect_uri.host && (redirect_uri.path =~ %r{/login} || redirect_uri.path =~ %r{/session}) @status = :resolved return @uri end old_uri = @uri location = "#{location}##{@uri.fragment}" if @preserve_fragment_url && @uri.fragment.present? location = "#{@uri.scheme}://#{@uri.host}#{location}" if location[0] == "/" @uri = uri(location) if @uri && @limit == @max_redirects && @https_redirect_ignore_limit && same_uri_but_https?(old_uri, @uri) @limit += 1 @https_redirect_ignore_limit = false end @limit -= 1 # https redirect, so just cache that whole new domain is https if old_uri.port == 80 && @uri&.port == 443 && (URI::HTTPS === @uri) FinalDestination.cache_https_domain(@uri.hostname) end return resolve end # this is weird an exception seems better @status = :failure @status_code = response.status log(:warn, "FinalDestination could not resolve URL (status #{response.status}): #{@uri}") nil rescue Excon::Errors::Timeout log(:warn, "FinalDestination could not resolve URL (timeout): #{@uri}") nil end |
#skip_validations? ⇒ Boolean
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# File 'lib/final_destination.rb', line 400 def skip_validations? !@validate_uri end |
#small_get(request_headers) ⇒ Object
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# File 'lib/final_destination.rb', line 131 def small_get(request_headers) status_code, response_headers = nil catch(:done) do FinalDestination::HTTP.start( @uri.host, @uri.port, use_ssl: @uri.is_a?(URI::HTTPS), open_timeout: timeout, ) do |http| http.read_timeout = timeout http.request_get(@uri.request_uri, request_headers) do |resp| status_code = resp.code.to_i response_headers = resp.to_hash # see: https://bugs.ruby-lang.org/issues/15624 # if we allow response to return then body will be read # got to abort without reading body throw :done end end end [status_code, response_headers] end |
#timeout ⇒ Object
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# File 'lib/final_destination.rb', line 109 def timeout @timeout || FinalDestination.connection_timeout end |
#validate_uri ⇒ Object
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# File 'lib/final_destination.rb', line 404 def validate_uri skip_validations? || validate_uri_format end |
#validate_uri_format ⇒ Object
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# File 'lib/final_destination.rb', line 408 def validate_uri_format return false unless @uri && @uri.host return false if %w[https http].exclude?(@uri.scheme) # In some cases (like local/test environments) we may want to allow http URLs # to be used for internal hosts, but only if it's the case that the host is # explicitly used for SiteSetting.s3_endpoint. This is to allow for local # S3 providers like minio. # # In all other cases, we should not be allowing http calls to anything except # port 80. return false if @uri.scheme == "http" && !http_port_ok? return false if @uri.scheme == "https" && @uri.port != 443 # Disallow IP based crawling ( begin IPAddr.new(@uri.hostname) rescue StandardError nil end ).nil? end |