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[flashproxy/js] Poll the facilitator in a loop.
by dcf＠torproject.org 02 Apr '12

02 Apr '12

commit 7fd20939a00ec521f31821305199fd6708b3a39d Author: David Fifield <david(a)bamsoftware.com> Date: Sat Mar 31 15:44:47 2012 -0700 Poll the facilitator in a loop. --- flashproxy.js | 20 ++++++++++++-------- 1 files changed, 12 insertions(+), 8 deletions(-) diff --git a/flashproxy.js b/flashproxy.js index 4a758f9..7e0217e 100644 --- a/flashproxy.js +++ b/flashproxy.js @@ -217,12 +217,11 @@ function FlashProxy() this.proxy_pairs = []; this.start = function() { - var fac_addr; var client_addr; var relay_addr; - fac_addr = get_query_param_addr(this.query, "facilitator", DEFAULT_FACILITATOR_ADDR); - if (!fac_addr) { + this.fac_addr = get_query_param_addr(this.query, "facilitator", DEFAULT_FACILITATOR_ADDR); + if (!this.fac_addr) { puts("Error: Facilitator spec must be in the form \"host:port\"."); return; } @@ -250,18 +249,21 @@ function FlashProxy() puts("Error: the \"relay\" parameter requires \"client\" also.") return; } else { - this.proxy_main(fac_addr); + this.proxy_main(); } }; - this.proxy_main = function(fac_addr) { + this.proxy_main = function() { var fac_url; var xhr; - puts("Using facilitator " + format_addr(fac_addr) + "."); + if (this.proxy_pairs.length >= this.max_num_proxy_pairs) { + setTimeout(this.proxy_main.bind(this), this.facilitator_poll_interval); + return; + } - fac_url = "http://" + encodeURIComponent(fac_addr.host) - + ":" + encodeURIComponent(fac_addr.port) + "/"; + fac_url = "http://" + encodeURIComponent(this.fac_addr.host) + + ":" + encodeURIComponent(this.fac_addr.port) + "/"; xhr = new XMLHttpRequest(); try { xhr.open("GET", fac_url); @@ -294,6 +296,8 @@ function FlashProxy() var client_addr; var relay_addr; + setTimeout(this.proxy_main.bind(this), this.facilitator_poll_interval * 1000); + response = parse_query_string(text); if (!response.client) {

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[flashproxy/js] Add a badge class with a counter.
by dcf＠torproject.org 02 Apr '12

02 Apr '12

commit cbaa1c2982eb6d5703b8ee77d042fc72d4e01d73 Author: David Fifield <david(a)bamsoftware.com> Date: Sat Mar 31 16:45:03 2012 -0700 Add a badge class with a counter. --- embed.html | 22 ++++++++++++++++ flashproxy.js | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 91 insertions(+), 9 deletions(-) diff --git a/embed.html b/embed.html index c88827b..d572bdb 100644 --- a/embed.html +++ b/embed.html @@ -7,6 +7,28 @@ body { margin: 0; padding: 0; } +#flashproxy-badge { + position: relative; + margin: 0; + padding: 0; + width: 70px; + height: 23px; +} +#flashproxy-badge div { + position: absolute; + width: 70px; + top: 4px; +} +#flashproxy-badge div p { + top: 20px; + margin: 0; + padding: 0; + margin-left: 47px; + margin-right: 2px; + text-align: center; + color: white; + font-size: 12px; +} #flashproxy-badge.debug { position: absolute; margin: 0; diff --git a/flashproxy.js b/flashproxy.js index 7e0217e..640e236 100644 --- a/flashproxy.js +++ b/flashproxy.js @@ -29,6 +29,8 @@ * query is not done. The "client" parameter must be given as well. */ +var FLASHPROXY_INFO_URL = "https://crypto.stanford.edu/flashproxy/"; + var DEFAULT_FACILITATOR_ADDR = { host: "tor-facilitator.bamsoftware.com", port: 9002 @@ -180,20 +182,13 @@ function FlashProxy() this.query = parse_query_string(window.location.search.substr(1)); + this.badge = new Badge(); if (this.query.debug) { debug_div = document.createElement("pre"); debug_div.className = "debug"; - this.badge_elem = debug_div; } else { - var img; - - debug_div = undefined; - img = document.createElement("img"); - img.setAttribute("src", "https://crypto.stanford.edu/flashproxy/badge.png"); - img.setAttribute("border", 0); - - this.badge_elem = img; + this.badge_elem = this.badge.elem; } this.badge_elem.setAttribute("id", "flashproxy-badge"); @@ -333,8 +328,11 @@ function FlashProxy() puts("Complete."); /* Delete from the list of active proxy pairs. */ this.proxy_pairs.splice(this.proxy_pairs.indexOf(proxy_pair), 1); + this.badge.proxy_end(); }.bind(this); proxy_pair.connect(); + + this.badge.proxy_begin(); }; /* An instance of a client-relay connection. */ @@ -461,6 +459,68 @@ function FlashProxy() } } +var HTML_ESCAPES = { + "&": "amp", + "<": "lt", + ">": "gt", + "'": "apos", + "\"": "quot" +}; +function escape_html(s) +{ + return s.replace(/&<>'"/, function(x) { return HTML_ESCAPES[x] }); +} + +/* The usual embedded HTML badge. The "elem" member is a DOM element that can be + included elsewhere. */ +function Badge() +{ + /* Number of proxy pairs currently connected. */ + this.num_proxy_pairs = 0; + /* Number of proxy pairs ever connected. */ + this.total_proxy_pairs = 0; + + this.counter_text = document.createElement("p"); + + var div, subdiv, a, img; + + div = document.createElement("div"); + + a = document.createElement("a"); + a.setAttribute("href", FLASHPROXY_INFO_URL); + + img = document.createElement("img"); + img.setAttribute("src", "https://crypto.stanford.edu/flashproxy/badge.png"); + + subdiv = document.createElement("div"); + + this.counter_text = document.createElement("p"); + + div.appendChild(a); + a.appendChild(img); + div.appendChild(subdiv) + subdiv.appendChild(this.counter_text); + + this.elem = div; + + this.proxy_begin = function() { + this.num_proxy_pairs++; + this.total_proxy_pairs++; + this.refresh(); + }; + + this.proxy_end = function() { + this.num_proxy_pairs--; + this.refresh(); + } + + this.refresh = function() { + this.counter_text.innerHTML = escape_html(String(this.num_proxy_pairs)); + }; + + this.refresh(); +} + /* This is the non-functional badge that occupies space when flashproxy_should_disable decides that the proxy shouldn't run. */ function DummyFlashProxy()

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[flashproxy/js] Use relative URL for badge.png.
by dcf＠torproject.org 02 Apr '12

02 Apr '12

commit 9efecfd7be9ced260fa5106d73b8e9e68d924e45 Author: David Fifield <david(a)bamsoftware.com> Date: Sat Mar 31 16:47:53 2012 -0700 Use relative URL for badge.png. --- flashproxy.js | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/flashproxy.js b/flashproxy.js index 754e22e..178b7ba 100644 --- a/flashproxy.js +++ b/flashproxy.js @@ -488,7 +488,7 @@ function Badge() a.setAttribute("href", FLASHPROXY_INFO_URL); img = document.createElement("img"); - img.setAttribute("src", "https://crypto.stanford.edu/flashproxy/badge.png"); + img.setAttribute("src", "badge.png"); subdiv = document.createElement("div");

1 0

[flashproxy/js] Remove debugging line.
by dcf＠torproject.org 02 Apr '12

02 Apr '12

commit eb2b940c72f9f0828db045af1479c20b9b25c9b6 Author: David Fifield <david(a)bamsoftware.com> Date: Sat Mar 31 16:45:27 2012 -0700 Remove debugging line. --- flashproxy.js | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/flashproxy.js b/flashproxy.js index 640e236..754e22e 100644 --- a/flashproxy.js +++ b/flashproxy.js @@ -320,8 +320,6 @@ function FlashProxy() this.make_proxy_pair = function(client_addr, relay_addr) { var proxy_pair; - puts("make_proxy_pair"); - proxy_pair = new ProxyPair(client_addr, relay_addr); this.proxy_pairs.push(proxy_pair); proxy_pair.complete_callback = function(event) {

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[flashproxy/js] Make badge.png transparent and control its color with CSS.
by dcf＠torproject.org 02 Apr '12

02 Apr '12

commit 4103253a215eb394bd7effff90182294e0c29a85 Author: David Fifield <david(a)bamsoftware.com> Date: Sat Mar 31 16:48:07 2012 -0700 Make badge.png transparent and control its color with CSS. --- badge.png | Bin 270 -> 230 bytes embed.html | 1 + 2 files changed, 1 insertions(+), 0 deletions(-) diff --git a/badge.png b/badge.png index d832e24..17d2c79 100644 Binary files a/badge.png and b/badge.png differ diff --git a/embed.html b/embed.html index d572bdb..607d077 100644 --- a/embed.html +++ b/embed.html @@ -13,6 +13,7 @@ body { padding: 0; width: 70px; height: 23px; + background-color: #d80; } #flashproxy-badge div { position: absolute;

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[flashproxy/js] Add a die function to alert when the proxy has stopped working.
by dcf＠torproject.org 02 Apr '12

02 Apr '12

commit fc83bfec46599ab12569e5b0d93c907f1b5c8255 Author: David Fifield <david(a)bamsoftware.com> Date: Sat Mar 31 16:57:52 2012 -0700 Add a die function to alert when the proxy has stopped working. --- flashproxy.js | 15 +++++++++++++++ 1 files changed, 15 insertions(+), 0 deletions(-) diff --git a/flashproxy.js b/flashproxy.js index 178b7ba..786f428 100644 --- a/flashproxy.js +++ b/flashproxy.js @@ -218,18 +218,21 @@ function FlashProxy() this.fac_addr = get_query_param_addr(this.query, "facilitator", DEFAULT_FACILITATOR_ADDR); if (!this.fac_addr) { puts("Error: Facilitator spec must be in the form \"host:port\"."); + this.die(); return; } this.max_num_proxy_pairs = get_query_param_integer(this.query, "max_clients", DEFAULT_MAX_NUM_PROXY_PAIRS); if (this.max_num_proxy_pairs == null || this.max_num_proxy_pairs < 0) { puts("Error: max_clients must be a nonnegative integer."); + this.die(); return; } this.facilitator_poll_interval = get_query_param_timespec(this.query, "facilitator_poll_interval", DEFAULT_FACILITATOR_POLL_INTERVAL); if (this.facilitator_poll_interval == null || this.facilitator_poll_interval < MIN_FACILITATOR_POLL_INTERVAL) { puts("Error: facilitator_poll_interval must be a nonnegative number at least " + MIN_FACILITATOR_POLL_INTERVAL + "."); + this.die(); return; } @@ -239,9 +242,11 @@ function FlashProxy() this.make_proxy_pair(client_addr, relay_addr); } else if (client_addr !== undefined) { puts("Error: the \"client\" parameter requires \"relay\" also.") + this.die(); return; } else if (relay_addr !== undefined) { puts("Error: the \"relay\" parameter requires \"client\" also.") + this.die(); return; } else { this.proxy_main(); @@ -269,6 +274,7 @@ function FlashProxy() like "Component returned failure code: 0x805e0006 [nsIXMLHttpRequest.open]" on Firefox. */ puts("Facilitator: exception while connecting: " + repr(err.message) + "."); + this.die(); return; } xhr.responseType = "text"; @@ -333,6 +339,11 @@ function FlashProxy() this.badge.proxy_begin(); }; + this.die = function() { + puts("die"); + this.badge.set_color("#111"); + } + /* An instance of a client-relay connection. */ function ProxyPair(client_addr, relay_addr) { @@ -516,6 +527,10 @@ function Badge() this.counter_text.innerHTML = escape_html(String(this.num_proxy_pairs)); }; + this.set_color = function(color) { + this.elem.style.backgroundColor = color; + }; + this.refresh(); }

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[flashproxy/js] Call the complete_callback only once.
by dcf＠torproject.org 02 Apr '12

02 Apr '12

commit 3859bdc7d66d62188b1869fa095d6d3f30b14e68 Author: David Fifield <david(a)bamsoftware.com> Date: Sat Mar 31 17:12:06 2012 -0700 Call the complete_callback only once. --- flashproxy.js | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/flashproxy.js b/flashproxy.js index e55e26b..78b40aa 100644 --- a/flashproxy.js +++ b/flashproxy.js @@ -360,6 +360,7 @@ function FlashProxy() this.c2r_schedule = []; this.r2c_schedule = []; + this.running = true; this.flush_timeout_id = null; /* This callback function can be overridden by external callers. */ @@ -390,8 +391,10 @@ function FlashProxy() log(ws.label + ": closed."); this.flush(); - if (is_closed(this.client_s) && is_closed(this.relay_s)) + if (this.running && is_closed(this.client_s) && is_closed(this.relay_s)) { + this.running = false; this.complete_callback(); + } }.bind(this); this.onmessage_client_to_relay = function(event) {

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[flashproxy/js] Add rate limiting.
by dcf＠torproject.org 02 Apr '12

02 Apr '12

commit 35d93b048ddad2760d4ba4ee8db8e49ab44524f6 Author: David Fifield <david(a)bamsoftware.com> Date: Sat Mar 31 17:21:11 2012 -0700 Add rate limiting. --- flashproxy.js | 142 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 files changed, 135 insertions(+), 7 deletions(-) diff --git a/flashproxy.js b/flashproxy.js index 78b40aa..4803fce 100644 --- a/flashproxy.js +++ b/flashproxy.js @@ -27,6 +27,11 @@ * The address of the relay to connect to. The proxy normally receives this * information from the facilitator. When this option is used, the facilitator * query is not done. The "client" parameter must be given as well. + * + * ratelimit=<FLOAT>(<UNIT>)?|off + * What rate to limit all proxy traffic combined to. The special value "off" + * disables the limit. The default is DEFAULT_RATE_LIMIT. There is a + * sanity-check minimum of "10K". */ var FLASHPROXY_INFO_URL = "https://crypto.stanford.edu/flashproxy/"; @@ -41,6 +46,11 @@ var DEFAULT_MAX_NUM_PROXY_PAIRS = 10; var DEFAULT_FACILITATOR_POLL_INTERVAL = 10.0; var MIN_FACILITATOR_POLL_INTERVAL = 1.0; +/* Bytes per second. Set to undefined to disable limit. */ +var DEFAULT_RATE_LIMIT = undefined; +var MIN_RATE_LIMIT = 10 * 1024; +var RATE_LIMIT_HISTORY = 5.0; + /* Parse a URL query string or application/x-www-form-urlencoded body. The return type is an object mapping string keys to string values. By design, this function doesn't support multiple values for the same named parameter, @@ -143,6 +153,49 @@ function get_query_param_timespec(query, param, default_val) return get_query_param_number(query, param, default_val); } +/* Parse a count of bytes. A suffix of "k", "m", or "g" (or uppercase) + does what you would think. Returns null on error. */ +function parse_byte_count(spec) +{ + var UNITS = { + k: 1024, m: 1024 * 1024, g: 1024 * 1024 * 1024, + K: 1024, M: 1024 * 1024, G: 1024 * 1024 * 1024 + }; + var count, units; + var matches; + + matches = spec.match(/^(\d+(?:\.\d*)?)(\w*)$/); + if (matches == null) + return null; + + count = Number(matches[1]); + if (isNaN(count)) + return null; + + if (matches[2] == "") { + units = 1; + } else { + units = UNITS[matches[2]]; + if (units == null) + return null; + } + + return count * Number(units); +} + +/* Get a count of bytes from a string specification like "100" or "1.3m". + Returns null on error. */ +function get_query_param_byte_count(query, param, default_val) +{ + var spec; + + spec = query[param]; + if (spec === undefined) + return default_val; + else + return parse_byte_count(spec); +} + /* Parse an address in the form "host:port". Returns an Object with keys "host" (String) and "port" (int). Returns null on error. */ function parse_addr_spec(spec) @@ -179,6 +232,7 @@ function make_websocket(addr) function FlashProxy() { var debug_div; + var rate_limit; this.query = parse_query_string(window.location.search.substr(1)); @@ -204,16 +258,12 @@ function FlashProxy() } }; - var rate_limit = { - is_limited: function() { return false; }, - when: function() { return 0; } - }; - this.proxy_pairs = []; this.start = function() { var client_addr; var relay_addr; + var rate_limit_bytes; this.fac_addr = get_query_param_addr(this.query, "facilitator", DEFAULT_FACILITATOR_ADDR); if (!this.fac_addr) { @@ -236,6 +286,20 @@ function FlashProxy() return; } + if (this.query["ratelimit"] == "off") + rate_limit_bytes = undefined; + else + rate_limit_bytes = get_query_param_byte_count(this.query, "ratelimit", DEFAULT_RATE_LIMIT); + if (rate_limit_bytes === undefined) { + rate_limit = new DummyRateLimit(); + } else if (rate_limit_bytes == null || rate_limit_bytes < MIN_FACILITATOR_POLL_INTERVAL) { + puts("Error: ratelimit must be a nonnegative number at least " + MIN_RATE_LIMIT + "."); + this.die(); + return; + } else { + rate_limit = new BucketRateLimit(rate_limit_bytes * RATE_LIMIT_HISTORY, RATE_LIMIT_HISTORY); + } + client_addr = get_query_param_addr(this.query, "client"); relay_addr = get_query_param_addr(this.query, "relay"); if (client_addr !== undefined && relay_addr !== undefined) { @@ -447,13 +511,19 @@ function FlashProxy() busy = true; while (busy && !rate_limit.is_limited()) { + var chunk; + busy = false; if (is_open(this.client_s) && this.r2c_schedule.length > 0) { - this.client_s.send(this.r2c_schedule.shift()); + chunk = this.r2c_schedule.shift(); + rate_limit.update(chunk.length); + this.client_s.send(chunk); busy = true; } if (is_open(this.relay_s) && this.c2r_schedule.length > 0) { - this.relay_s.send(this.c2r_schedule.shift()); + chunk = this.c2r_schedule.shift(); + rate_limit.update(chunk.length); + this.relay_s.send(chunk); busy = true; } } @@ -473,6 +543,64 @@ function FlashProxy() } } +function BucketRateLimit(capacity, time) +{ + this.amount = 0.0; + /* capacity / time is the rate we are aiming for. */ + this.capacity = capacity; + this.time = time; + this.last_update = new Date(); + + this.age = function() { + var now; + var delta; + + now = new Date(); + delta = (now - this.last_update) / 1000.0; + this.last_update = now; + + this.amount -= delta * this.capacity / this.time; + if (this.amount < 0.0) + this.amount = 0.0; + }; + + this.update = function(n) { + this.age(); + this.amount += n; + + return this.amount <= this.capacity; + }; + + /* How many seconds in the future will the limit expire? */ + this.when = function() { + this.age(); + + return (this.amount - this.capacity) / (this.capacity / this.time); + } + + this.is_limited = function() { + this.age(); + + return this.amount > this.capacity; + } +} + +/* A rate limiter that never limits. */ +function DummyRateLimit(capacity, time) +{ + this.update = function(n) { + return true; + }; + + this.when = function() { + return 0.0; + } + + this.is_limited = function() { + return false; + } +} + var HTML_ESCAPES = { "&": "amp", "<": "lt",

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[flashproxy/js] Add missing returns on error conditions.
by dcf＠torproject.org 02 Apr '12

02 Apr '12

commit 1fa2068648ffc2368ef1a381bca1aac89aace513 Author: David Fifield <david(a)bamsoftware.com> Date: Sat Mar 31 16:58:11 2012 -0700 Add missing returns on error conditions. --- flashproxy.js | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/flashproxy.js b/flashproxy.js index 786f428..e55e26b 100644 --- a/flashproxy.js +++ b/flashproxy.js @@ -308,6 +308,7 @@ function FlashProxy() client_addr = parse_addr_spec(response.client); if (client_addr === null) { puts("Error: can't parse client spec " + repr(response.client) + "."); + return; } if (!response.relay) { puts("Error: missing relay in response."); @@ -316,6 +317,7 @@ function FlashProxy() relay_addr = parse_addr_spec(response.relay); if (relay_addr === null) { puts("Error: can't parse relay spec " + repr(response.relay) + "."); + return; } puts("Facilitator: got client:" + repr(client_spec) + " " + "relay:" + repr(relay_spec) + ".");

1 0

[flashproxy/js] Remove *.as files.
by dcf＠torproject.org 02 Apr '12

02 Apr '12

commit cb5640e7a478cebac59e91144e69992d5593d490 Author: David Fifield <david(a)bamsoftware.com> Date: Sat Mar 31 17:45:58 2012 -0700 Remove *.as files. --- Makefile | 14 +-- ProxyPair.as | 194 -------------------- swfcat.as | 566 ---------------------------------------------------------- 3 files changed, 3 insertions(+), 771 deletions(-) diff --git a/Makefile b/Makefile index 61c3901..94c5d1f 100644 --- a/Makefile +++ b/Makefile @@ -1,23 +1,15 @@ PREFIX = /usr/local BINDIR = $(PREFIX)/bin -MXMLC ?= mxmlc - -TARGETS = swfcat.swf - -all: $(TARGETS) - -swfcat.swf: *.as badge.png - -%.swf: %.as - $(MXMLC) -output $@ -static-link-runtime-shared-libraries $< +all: + : install: mkdir -p $(BINDIR) cp -f connector.py facilitator.py $(BINDIR) clean: - rm -f $(TARGETS) + : test: ./connector-test.py diff --git a/ProxyPair.as b/ProxyPair.as deleted file mode 100644 index 237ab69..0000000 --- a/ProxyPair.as +++ /dev/null @@ -1,194 +0,0 @@ -package -{ - import flash.events.Event; - import flash.events.EventDispatcher; - import flash.events.IOErrorEvent; - import flash.events.ProgressEvent; - import flash.events.SecurityErrorEvent; - import flash.events.TextEvent; - import flash.net.Socket; - import flash.utils.ByteArray; - import flash.utils.clearTimeout; - import flash.utils.setTimeout; - - /* An instance of a client-relay connection. */ - public class ProxyPair extends EventDispatcher - { - // Label for log messages. - public var name:String; - - // Socket to client. - private var s_c:*; - private var connect_c:Function; - - // Socket to relay. - private var s_r:*; - private var connect_r:Function; - - // Parent swfcat, for UI updates and rate meter. - private var ui:swfcat; - - // Pending byte read counts for relay and client sockets. - private var r2c_schedule:Array; - private var c2r_schedule:Array; - // Callback id. - private var flush_id:uint; - - public function log(msg:String):void - { - if (name) - ui.puts(name + ": " + msg) - else - ui.puts(msg) - } - - public function logdebug(msg:String):void - { - if (ui.debug) - log(msg); - } - - public function set_name(name:String):void - { - this.name = name; - } - - public function ProxyPair(ui:swfcat, s_c:*, connect_c:Function, s_r:*, connect_r:Function) - { - this.ui = ui; - /* s_c is a socket for connecting to the client. connect_c is a - function that, when called, connects s_c. Likewise for s_r and - connect_r. */ - this.s_c = s_c; - this.connect_c = connect_c; - this.s_r = s_r; - this.connect_r = connect_r; - - this.c2r_schedule = []; - this.r2c_schedule = []; - } - - /* Return a function that shows an error message and closes the other half - of a communication pair. */ - private function socket_error(message:String, other:*):Function - { - return function(e:Event):void { - if (e is TextEvent) - log(message + ": " + (e as TextEvent).text + "."); - else - log(message + "."); - if (other && other.connected) - other.close(); - dispatchEvent(new Event(Event.COMPLETE)); - }; - } - - public function connect():void - { - s_r.addEventListener(Event.CONNECT, relay_connected); - s_r.addEventListener(Event.CLOSE, relay_closed); - s_r.addEventListener(IOErrorEvent.IO_ERROR, socket_error("Relay: I/O error", s_c)); - s_r.addEventListener(SecurityErrorEvent.SECURITY_ERROR, socket_error("Relay: security error", s_c)); - s_r.addEventListener(ProgressEvent.SOCKET_DATA, relay_to_client); - - s_c.addEventListener(Event.CONNECT, client_connected); - s_c.addEventListener(Event.CLOSE, client_closed); - s_c.addEventListener(IOErrorEvent.IO_ERROR, socket_error("Client: I/O error", s_r)); - s_c.addEventListener(SecurityErrorEvent.SECURITY_ERROR, socket_error("Client: security error", s_r)); - s_c.addEventListener(ProgressEvent.SOCKET_DATA, client_to_relay); - - log("Relay: connecting."); - connect_r(); - log("Client: connecting."); - connect_c(); - } - - private function relay_connected(e:Event):void - { - log("Relay: connected."); - } - - private function client_connected(e:Event):void - { - log("Client: connected."); - } - - private function relay_closed(e:Event):void - { - log("Relay: closed."); - flush(); - } - - private function client_closed(e:Event):void - { - log("Client: closed."); - flush(); - } - - private function relay_to_client(e:ProgressEvent):void - { - r2c_schedule.push(e.bytesLoaded); - flush(); - } - - private function client_to_relay(e:ProgressEvent):void - { - c2r_schedule.push(e.bytesLoaded); - flush(); - } - - private function transfer_chunk(s_from:*, s_to:*, n:uint, - label:String):void - { - var bytes:ByteArray; - - bytes = new ByteArray(); - s_from.readBytes(bytes, 0, n); - s_to.writeBytes(bytes); - s_to.flush(); - ui.rate_limit.update(n); - logdebug(label + ": read " + bytes.length + "."); - } - - /* Send as much data as the rate limit currently allows. */ - private function flush():void - { - var busy:Boolean; - - if (flush_id) - clearTimeout(flush_id); - flush_id = undefined; - - if (!s_r.connected && !s_c.connected) - /* Can't do anything while both sockets are disconnected. */ - return; - - busy = true; - while (busy && !ui.rate_limit.is_limited()) { - busy = false; - if (s_c.connected && r2c_schedule.length > 0) { - transfer_chunk(s_r, s_c, r2c_schedule.shift(), "Relay"); - busy = true; - } - if (s_r.connected && c2r_schedule.length > 0) { - transfer_chunk(s_c, s_r, c2r_schedule.shift(), "Client"); - busy = true; - } - } - - if (!s_r.connected && r2c_schedule.length == 0) { - log("Client: closing."); - s_c.close(); - } - if (!s_c.connected && c2r_schedule.length == 0) { - log("Relay: closing."); - s_r.close(); - } - - if (!s_c.connected && !s_r.connected) - dispatchEvent(new Event(Event.COMPLETE)); - else if (r2c_schedule.length > 0 || c2r_schedule.length > 0) - flush_id = setTimeout(flush, ui.rate_limit.when() * 1000); - } - } -} diff --git a/swfcat.as b/swfcat.as deleted file mode 100644 index 13d8788..0000000 --- a/swfcat.as +++ /dev/null @@ -1,566 +0,0 @@ -/* Flash parameters. These can change how the program runs from the outside. - * They can be set as a URL query string, for example: - * http://www.example.com/swfcat.swf?facilitator=127.0.0.1:9002&debug=1 - * or in the HTML markup for the embedding of the movie: - * <object> - * <param name="movie" value="http://www.example.com/swfcat.swf"> - * <param name="flashvars" value="facilitator=127.0.0.1:9002&debug=1"> - * <embed src="http://www.example.com/swfcat.swf" - * flashvars="facilitator=127.0.0.1:9002&debug=1"></embed> - * </object> - * - * debug=1 - * If set (to any value), show verbose terminal-like output instead of the - * badge. - * - * facilitator=<HOST>:<PORT> - * The address of the facilitator to use. By default it is - * DEFAULT_FACILITATOR_ADDR. Both <HOST> and <PORT> must be present. - * - * max_clients=<NUM> - * How many clients to serve concurrently. The default is - * DEFAULT_MAX_NUM_PROXY_PAIRS. - * - * facilitator_poll_interval=<FLOAT> - * How often to poll the facilitator, in seconds. The default is - * DEFAULT_FACILITATOR_POLL_INTERVAL. There is a sanity-check minimum of 1.0 s. - * - * ratelimit=<FLOAT>(<UNIT>)?|off - * What rate to limit all proxy traffic combined to. The special value "off" - * disables the limit. The default is DEFAULT_RATE_LIMIT. There is a - * sanity-check minimum of "10K". - */ - -package -{ - import flash.display.Sprite; - import flash.display.StageAlign; - import flash.display.StageScaleMode; - import flash.events.Event; - import flash.events.IOErrorEvent; - import flash.events.SecurityErrorEvent; - import flash.external.ExternalInterface; - import flash.net.Socket; - import flash.net.URLLoader; - import flash.net.URLLoaderDataFormat; - import flash.net.URLRequest; - import flash.net.URLRequestMethod; - import flash.net.URLVariables; - import flash.text.TextField; - import flash.text.TextFormat; - import flash.utils.setTimeout; - - public class swfcat extends Sprite - { - private const DEFAULT_FACILITATOR_ADDR:Object = { - host: "tor-facilitator.bamsoftware.com", - port: 9002 - }; - - private const DEFAULT_MAX_NUM_PROXY_PAIRS:uint = 10; - - /* In seconds. */ - private const DEFAULT_FACILITATOR_POLL_INTERVAL:Number = 10.0; - private const MIN_FACILITATOR_POLL_INTERVAL:Number = 1.0; - - // Bytes per second. Set to undefined to disable limit. - public static const DEFAULT_RATE_LIMIT:Number = undefined; - public static const MIN_RATE_LIMIT:Number = 10 * 1024; - // Seconds. - private static const RATE_LIMIT_HISTORY:Number = 5.0; - - /* TextField for debug output. */ - private var output_text:TextField; - - /* UI shown when debug is off. */ - private var badge:Badge; - - /* Proxy pairs currently connected (up to max_num_proxy_pairs). */ - private var proxy_pairs:Array; - - public var debug:Boolean; - private var fac_addr:Object; - private var max_num_proxy_pairs:uint; - private var facilitator_poll_interval:Number; - - public var rate_limit:RateLimit; - - public function puts(s:String):void - { - if (output_text) { - output_text.appendText(s + "\n"); - output_text.scrollV = output_text.maxScrollV; - } - } - - public function swfcat() - { - // Absolute positioning. - stage.scaleMode = StageScaleMode.NO_SCALE; - stage.align = StageAlign.TOP_LEFT; - - badge = new Badge(); - - proxy_pairs = []; - - // Wait until the query string parameters are loaded. - this.loaderInfo.addEventListener(Event.COMPLETE, loaderinfo_complete); - } - - private function loaderinfo_complete(e:Event):void - { - var tmp:*; - - debug = this.loaderInfo.parameters["debug"]; - - if (debug) { - output_text = new TextField(); - output_text.width = stage.stageWidth; - output_text.height = stage.stageHeight; - output_text.background = true; - output_text.backgroundColor = 0x001f0f; - output_text.textColor = 0x44cc44; - addChild(output_text); - } else { - addChild(badge); - } - - puts("Parameters loaded."); - - fac_addr = get_param_addr("facilitator", DEFAULT_FACILITATOR_ADDR); - if (!fac_addr) { - puts("Error: Facilitator spec must be in the form \"host:port\"."); - return; - } - - tmp = get_param_number("max_clients", DEFAULT_MAX_NUM_PROXY_PAIRS); - if (tmp == null || tmp < 0) { - puts("Error: max_clients must be a nonnegative integer."); - return; - } - max_num_proxy_pairs = uint(tmp); - - tmp = get_param_timespec("facilitator_poll_interval", DEFAULT_FACILITATOR_POLL_INTERVAL); - if (tmp == null || tmp < MIN_FACILITATOR_POLL_INTERVAL) { - puts("Error: facilitator_poll_interval must be a nonnegative number at least " + MIN_FACILITATOR_POLL_INTERVAL + "."); - return; - } - facilitator_poll_interval = Number(tmp); - - if (this.loaderInfo.parameters["ratelimit"] == "off") - tmp = undefined; - else - tmp = get_param_byte_count("ratelimit", DEFAULT_RATE_LIMIT); - if (tmp === undefined) { - /* No rate limit. */ - } else if (tmp == null || tmp < MIN_FACILITATOR_POLL_INTERVAL) { - puts("Error: ratelimit must be a nonnegative number at least " + MIN_RATE_LIMIT + "."); - return; - } - if (tmp) - rate_limit = new BucketRateLimit(Number(tmp) * RATE_LIMIT_HISTORY, RATE_LIMIT_HISTORY); - else - rate_limit = new RateUnlimit(); - - proxy_main(); - } - - /* Get an address structure from the given movie parameter, or the given - default. Returns null on error. */ - private function get_param_addr(param:String, default_addr:Object):Object - { - var spec:String; - - spec = this.loaderInfo.parameters[param]; - if (spec) - return parse_addr_spec(spec); - else - return default_addr; - } - - /* Get a number from the given movie parameter, or the given default. - Returns null on error. First check for a null return, and then call - uint or whatever on the return value if no error. */ - private function get_param_number(param:String, default_val:Number):Object - { - var spec:String; - var val:Number; - - spec = this.loaderInfo.parameters[param]; - if (spec) { - val = Number(spec); - if (isNaN(val)) - return null; - else - return val; - } else { - return default_val; - } - } - - /* Get a floating-point number of seconds from a time specification. The - only time specification format is a decimal number of seconds. - Returns null on error. */ - private function get_param_timespec(param:String, default_val:Number):Object - { - return get_param_number(param, default_val); - } - - /* Get a count of bytes from a string specification like "100" or - "1.3m". Returns null on error. */ - private function get_param_byte_count(param:String, default_val:Number):Object - { - var spec:String; - - spec = this.loaderInfo.parameters[param]; - if (spec) - return parse_byte_count(spec); - else - return default_val; - } - - /* The main logic begins here, after start-up issues are taken care of. */ - private function proxy_main():void - { - var fac_url:String; - var loader:URLLoader; - - if (proxy_pairs.length >= max_num_proxy_pairs) { - setTimeout(proxy_main, uint(facilitator_poll_interval * 1000)); - return; - } - - loader = new URLLoader(); - /* Get the x-www-form-urlencoded values. */ - loader.dataFormat = URLLoaderDataFormat.VARIABLES; - loader.addEventListener(Event.COMPLETE, fac_complete); - loader.addEventListener(IOErrorEvent.IO_ERROR, function (e:IOErrorEvent):void { - puts("Facilitator: I/O error: " + e.text + "."); - }); - loader.addEventListener(SecurityErrorEvent.SECURITY_ERROR, function (e:SecurityErrorEvent):void { - puts("Facilitator: security error: " + e.text + "."); - }); - - fac_url = "http://" + encodeURIComponent(fac_addr.host) - + ":" + encodeURIComponent(fac_addr.port) + "/"; - puts("Facilitator: connecting to " + fac_url + "."); - loader.load(new URLRequest(fac_url)); - } - - private function fac_complete(e:Event):void - { - var loader:URLLoader; - var client_spec:String; - var relay_spec:String; - var proxy_pair:Object; - - setTimeout(proxy_main, uint(facilitator_poll_interval * 1000)); - - loader = e.target as URLLoader; - client_spec = loader.data.client; - if (client_spec == "") { - puts("No clients."); - return; - } else if (!client_spec) { - puts("Error: missing \"client\" in response."); - return; - } - relay_spec = loader.data.relay; - if (!relay_spec) { - puts("Error: missing \"relay\" in response."); - return; - } - puts("Facilitator: got client:\"" + client_spec + "\" " - + "relay:\"" + relay_spec + "\"."); - - try { - proxy_pair = make_proxy_pair(client_spec, relay_spec); - } catch (e:ArgumentError) { - puts("Error: " + e); - return; - } - proxy_pairs.push(proxy_pair); - proxy_pair.addEventListener(Event.COMPLETE, function(e:Event):void { - proxy_pair.log("Complete."); - /* Delete from the list of active proxy pairs. */ - proxy_pairs.splice(proxy_pairs.indexOf(proxy_pair), 1); - badge.proxy_end(); - }); - proxy_pair.connect(); - - badge.proxy_begin(); - } - - private function make_proxy_pair(client_spec:String, relay_spec:String):ProxyPair - { - var proxy_pair:ProxyPair; - var addr_c:Object; - var addr_r:Object; - var s_c:*; - var s_r:Socket; - - addr_r = swfcat.parse_addr_spec(relay_spec); - if (!addr_r) - throw new ArgumentError("Relay spec must be in the form \"host:port\"."); - - addr_c = swfcat.parse_addr_spec(client_spec); - if (addr_c) { - s_c = new Socket(); - s_r = new Socket(); - proxy_pair = new ProxyPair(this, s_c, function ():void { - s_c.connect(addr_c.host, addr_c.port); - }, s_r, function ():void { - s_r.connect(addr_r.host, addr_r.port); - }); - proxy_pair.set_name("<" + addr_c.host + ":" + addr_c.port + "," - + addr_r.host + ":" + addr_r.port + ">"); - return proxy_pair; - } - - throw new ArgumentError("Can't parse client spec \"" + client_spec + "\"."); - } - - /* Parse an address in the form "host:port". Returns an Object with - keys "host" (String) and "port" (int). Returns null on error. */ - private static function parse_addr_spec(spec:String):Object - { - var parts:Array; - var addr:Object; - - parts = spec.split(":", 2); - if (parts.length != 2 || !parseInt(parts[1])) - return null; - addr = {} - addr.host = parts[0]; - addr.port = parseInt(parts[1]); - - return addr; - } - - /* Parse a count of bytes. A suffix of "k", "m", or "g" (or uppercase) - does what you would think. Returns null on error. */ - private static function parse_byte_count(spec:String):Object - { - const UNITS:Object = { - k: 1024, m: 1024 * 1024, g: 1024 * 1024 * 1024, - K: 1024, M: 1024 * 1024, G: 1024 * 1024 * 1024 - }; - var count:Number, units:Object; - var matches:Array; - - matches = spec.match(/^(\d+(?:\.\d*)?)(\w*)$/); - if (matches == null) - return null; - - count = Number(matches[1]); - if (isNaN(count)) - return null; - - if (matches[2] == "") { - units = 1; - } else { - units = UNITS[matches[2]]; - if (units == null) - return null; - } - - return count * Number(units); - } - } -} - -import flash.events.MouseEvent; -import flash.net.navigateToURL; -import flash.net.URLRequest; -import flash.text.TextField; -import flash.text.TextFormat; -import flash.utils.getTimer; - -class Badge extends flash.display.Sprite -{ - private const FLASHPROXY_INFO_URL:String = "https://crypto.stanford.edu/flashproxy/"; - - /* Number of proxy pairs currently connected. */ - private var num_proxy_pairs:int = 0; - /* Number of proxy pairs ever connected. */ - private var total_proxy_pairs:int = 0; - - [Embed(source="badge.png")] - private var BadgeImage:Class; - private var tot_client_count_tf:TextField; - private var tot_client_count_fmt:TextFormat; - private var cur_client_count_tf:TextField; - private var cur_client_count_fmt:TextFormat; - - public function Badge() - { - /* Setup client counter for badge. */ - tot_client_count_fmt = new TextFormat(); - tot_client_count_fmt.color = 0xFFFFFF; - tot_client_count_fmt.align = "center"; - tot_client_count_fmt.font = "courier-new"; - tot_client_count_fmt.bold = true; - tot_client_count_fmt.size = 10; - tot_client_count_tf = new TextField(); - tot_client_count_tf.width = 20; - tot_client_count_tf.height = 17; - tot_client_count_tf.background = false; - tot_client_count_tf.defaultTextFormat = tot_client_count_fmt; - tot_client_count_tf.x=47; - tot_client_count_tf.y=0; - - cur_client_count_fmt = new TextFormat(); - cur_client_count_fmt.color = 0xFFFFFF; - cur_client_count_fmt.align = "center"; - cur_client_count_fmt.font = "courier-new"; - cur_client_count_fmt.bold = true; - cur_client_count_fmt.size = 10; - cur_client_count_tf = new TextField(); - cur_client_count_tf.width = 20; - cur_client_count_tf.height = 17; - cur_client_count_tf.background = false; - cur_client_count_tf.defaultTextFormat = cur_client_count_fmt; - cur_client_count_tf.x=47; - cur_client_count_tf.y=6; - - addChild(new BadgeImage()); - addChild(tot_client_count_tf); - addChild(cur_client_count_tf); - - /* Update the client counter on badge. */ - update_client_count(); - - addEventListener(MouseEvent.CLICK, mouse_clicked); - } - - public function proxy_begin():void - { - num_proxy_pairs++; - total_proxy_pairs++; - update_client_count(); - } - - public function proxy_end():void - { - num_proxy_pairs--; - update_client_count(); - } - - private function update_client_count():void - { - /* Update total client count. */ - if (String(total_proxy_pairs).length == 1) - tot_client_count_tf.text = "0" + String(total_proxy_pairs); - else - tot_client_count_tf.text = String(total_proxy_pairs); - - /* Update current client count. */ - cur_client_count_tf.text = ""; - for(var i:Number = 0; i < num_proxy_pairs; i++) - cur_client_count_tf.appendText("."); - } - - /* Show a web page with detailed information when the badge is clicked. */ - private function mouse_clicked(e:MouseEvent):void - { - try { - navigateToURL(new URLRequest(FLASHPROXY_INFO_URL)); - } catch (err:Error) { - } - } -} - -class RateLimit -{ - public function RateLimit() - { - } - - public function update(n:Number):Boolean - { - return true; - } - - public function when():Number - { - return 0.0; - } - - public function is_limited():Boolean - { - return false; - } -} - -class RateUnlimit extends RateLimit -{ - public function RateUnlimit() - { - } - - public override function update(n:Number):Boolean - { - return true; - } - - public override function when():Number - { - return 0.0; - } - - public override function is_limited():Boolean - { - return false; - } -} - -class BucketRateLimit extends RateLimit -{ - private var amount:Number; - private var capacity:Number; - private var time:Number; - private var last_update:uint; - - public function BucketRateLimit(capacity:Number, time:Number) - { - this.amount = 0.0; - /* capacity / time is the rate we are aiming for. */ - this.capacity = capacity; - this.time = time; - this.last_update = getTimer(); - } - - private function age():void - { - var now:uint; - var delta:Number; - - now = getTimer(); - delta = (now - last_update) / 1000.0; - last_update = now; - - amount -= delta * capacity / time; - if (amount < 0.0) - amount = 0.0; - } - - public override function update(n:Number):Boolean - { - age(); - amount += n; - - return amount <= capacity; - } - - public override function when():Number - { - age(); - return (amount - capacity) / (capacity / time); - } - - public override function is_limited():Boolean - { - age(); - return amount > capacity; - } -}

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