From 5edee3c4d1f84c07c1c54775072601188075a542 Mon Sep 17 00:00:00 2001
From: Mike Macgirvin <mike@macgirvin.com>
Date: Thu, 21 Oct 2010 04:53:43 -0700
Subject: [PATCH] magic-envelope verification, status.net appears to do it
wrong. Ultimately we need to do it right (or why bother having a spec?), and
fallback to doing it wrong if we're talking to a broken system - which
ironically seems to include most of the federated social web projects.
---
boot.php | 73 ++++++++++++++-----
database.sql | 1 +
include/items.php | 2 +-
include/salmon.php | 109 +++++++++++++++++++++++++++++
library/asn1.php | 2 +-
mod/salmon.php | 170 +++++++++++++++++++++++++++++++++++++++++++--
update.php | 6 +-
view/fake_feed.tpl | 18 +++++
8 files changed, 354 insertions(+), 27 deletions(-)
create mode 100644 view/fake_feed.tpl
diff --git a/boot.php b/boot.php
index 8fec10afaa..55c244e827 100644
--- a/boot.php
+++ b/boot.php
@@ -2,7 +2,7 @@
set_time_limit(0);
-define ( 'BUILD_ID', 1010 );
+define ( 'BUILD_ID', 1011 );
define ( 'DFRN_PROTOCOL_VERSION', '2.0' );
define ( 'EOL', "<br />\r\n" );
@@ -116,6 +116,7 @@ class App {
private $db;
private $curl_code;
+ private $curl_headers;
function __construct() {
@@ -204,6 +205,15 @@ class App {
return $this->curl_code;
}
+ function set_curl_headers($headers) {
+ $this->curl_headers = $headers;
+ }
+
+ function get_curl_headers() {
+ return $this->curl_headers;
+ }
+
+
}}
// retrieve the App structure
@@ -339,13 +349,12 @@ function t($s) {
// results.
if(! function_exists('fetch_url')) {
-function fetch_url($url,$binary = false) {
+function fetch_url($url,$binary = false, &$redirects = 0) {
$ch = curl_init($url);
- if(! $ch) return false;
+ if(($redirects > 8) || (! $ch))
+ return false;
- curl_setopt($ch, CURLOPT_HEADER, 0);
- curl_setopt($ch, CURLOPT_FOLLOWLOCATION,true);
- curl_setopt($ch, CURLOPT_MAXREDIRS,8);
+ curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,true);
// by default we will allow self-signed certs
@@ -366,26 +375,41 @@ function fetch_url($url,$binary = false) {
curl_setopt($ch, CURLOPT_BINARYTRANSFER,1);
$s = curl_exec($ch);
- $info = curl_getinfo($ch);
+
+ $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+ $header = substr($s,0,strpos($s,"\r\n\r\n"));
+ if($http_code == 301 || $http_code == 302 || $http_code == 303) {
+ $matches = array();
+ preg_match('/(Location:|URI:)(.*?)\n/', $header, $matches);
+ $url = trim(array_pop($matches));
+ $url_parsed = parse_url($url);
+ if (isset($url_parsed)) {
+ $redirects++;
+ return fetch_url($url,$binary,$redirects);
+ }
+ }
$a = get_app();
- $a->set_curl_code($info['http_code']);
+ $a->set_curl_code($http_code);
+ $body = substr($s,strlen($header)+4);
+ $a->set_curl_headers($header);
+
curl_close($ch);
- return($s);
+ return($body);
}}
// post request to $url. $params is an array of post variables.
if(! function_exists('post_url')) {
-function post_url($url,$params) {
+function post_url($url,$params, &$redirects = 0) {
$ch = curl_init($url);
- if(! $ch) return false;
+ if(($redirects > 8) || (! $ch))
+ return false;
- curl_setopt($ch, CURLOPT_HEADER, 0);
- curl_setopt($ch, CURLOPT_FOLLOWLOCATION,true);
- curl_setopt($ch, CURLOPT_MAXREDIRS,8);
+ curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,true);
curl_setopt($ch, CURLOPT_POST,1);
curl_setopt($ch, CURLOPT_POSTFIELDS,$params);
+
$check_cert = get_config('system','verifyssl');
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, (($check_cert) ? true : false));
$prx = get_config('system','proxy');
@@ -398,11 +422,26 @@ function post_url($url,$params) {
}
$s = curl_exec($ch);
- $info = curl_getinfo($ch);
+
+ $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+ $header = substr($s,0,strpos($s,"\r\n\r\n"));
+ if($http_code == 301 || $http_code == 302 || $http_code == 303) {
+ $matches = array();
+ preg_match('/(Location:|URI:)(.*?)\n/', $header, $matches);
+ $url = trim(array_pop($matches));
+ $url_parsed = parse_url($url);
+ if (isset($url_parsed)) {
+ $redirects++;
+ return post_url($url,$binary,$redirects);
+ }
+ }
$a = get_app();
- $a->set_curl_code($info['http_code']);
+ $a->set_curl_code($http_code);
+ $body = substr($s,strlen($header)+4);
+ $a->set_curl_headers($header);
+
curl_close($ch);
- return($s);
+ return($body);
}}
// random hash, 64 chars
diff --git a/database.sql b/database.sql
index 7526be41d1..a3d78d79a3 100644
--- a/database.sql
+++ b/database.sql
@@ -62,6 +62,7 @@ CREATE TABLE IF NOT EXISTS `contact` (
`issued-id` char(255) NOT NULL,
`dfrn-id` char(255) NOT NULL,
`url` char(255) NOT NULL,
+ `lrdd` char(255) NOT NULL,
`pubkey` text NOT NULL,
`prvkey` text NOT NULL,
`request` text NOT NULL,
diff --git a/include/items.php b/include/items.php
index f04bf0bd87..eca050d4fe 100644
--- a/include/items.php
+++ b/include/items.php
@@ -139,7 +139,7 @@ function get_feed_for(&$a, $dfrn_id, $owner_id, $last_update, $direction = 0) {
}
$salmon = '<link rel="salmon" href="' . xmlify($a->get_baseurl() . '/salmon/' . $owner_nick) . '" />' . "\n" ;
- $salmon = ''; // remove this line when salmon handler is finished
+// $salmon = ''; // remove this line when salmon handler is finished
$atom .= replace_macros($feed_template, array(
'$feed_id' => xmlify($a->get_baseurl() . '/profile/' . $owner_nick),
diff --git a/include/salmon.php b/include/salmon.php
index 7198f07c60..bd2d620a81 100644
--- a/include/salmon.php
+++ b/include/salmon.php
@@ -16,3 +16,112 @@ function salmon_key($pubkey) {
return 'RSA' . '.' . $m . '.' . $e ;
}
+
+
+function base64url_encode($s) {
+ return strtr(base64_encode($s),'+/','-_');
+}
+
+function base64url_decode($s) {
+ return base64_decode(strtr($s,'-_','+/'));
+}
+
+function get_salmon_key($uri,$keyhash) {
+ $ret = array();
+
+ $debugging = get_config('system','debugging');
+ if($debugging)
+ file_put_contents('salmon.out', "\n" . 'Fetch key' . "\n", FILE_APPEND);
+
+ if(strstr($uri,'@')) {
+ $arr = webfinger($uri);
+ if($debugging)
+ file_put_contents('salmon.out', "\n" . 'Fetch key from webfinger' . "\n", FILE_APPEND);
+ }
+ else {
+ $html = fetch_url($uri);
+ $a = get_app();
+ $h = $a->get_curl_headers();
+ if($debugging)
+ file_put_contents('salmon.out', "\n" . 'Fetch key via HTML header: ' . $h . "\n", FILE_APPEND);
+
+ $l = explode("\n",$h);
+ if(count($l)) {
+ foreach($l as $line) {
+
+ if($debugging)
+ file_put_contents('salmon.out', "\n" . $line . "\n", FILE_APPEND);
+ if((stristr($line,'link:')) && preg_match('/<([^>].*)>.*rel\=[\'\"]lrdd[\'\"]/',$line,$matches)) {
+ $link = $matches[1];
+ if($debugging)
+ file_put_contents('salmon.out', "\n" . 'Fetch key via Link from header: ' . $link . "\n", FILE_APPEND);
+ break;
+ }
+ }
+ }
+ }
+
+ if(! isset($link)) {
+ require_once('library/HTML5/Parser.php');
+ $dom = HTML5_Parser::parse($html);
+
+ if(! $dom)
+ return '';
+
+ $items = $dom->getElementsByTagName('link');
+
+ foreach($items as $item) {
+ $x = $item->getAttribute('rel');
+ if($x == "lrdd") {
+ $link = $item->getAttribute('href');
+ if($debugging)
+ file_put_contents('salmon.out', "\n" . 'Fetch key via HTML body' . $link . "\n", FILE_APPEND);
+ break;
+ }
+ }
+ }
+
+ if(! isset($link))
+ return '';
+
+ $arr = fetch_xrd_links($link);
+
+ if($arr) {
+ foreach($arr as $a) {
+ if($a['@attributes']['rel'] === 'magic-public-key') {
+ $ret[] = $a['@attributes']['href'];
+ }
+ }
+ }
+ if(count($ret)) {
+ for($x = 0; $x < count($ret); $x ++) {
+ if(substr($ret[$x],0,5) === 'data:') {
+ if(strstr($ret[$x],','))
+ $ret[$x] = substr($ret[$x],strpos($ret[$x],',')+1);
+ else
+ $ret[$x] = substr($ret[$x],5);
+ }
+ else
+ $ret[$x] = fetch_url($ret[$x]);
+ }
+ }
+ if($debugging)
+ file_put_contents('salmon.out', "\n" . 'Key located: ' . print_r($ret,true) . "\n", FILE_APPEND);
+
+ if(count($ret) == 1) {
+ return $ret[0];
+ }
+ else {
+ foreach($ret as $a) {
+ $hash = base64url_encode(hash('sha256',$a));
+ if($hash == $keyhash)
+ return $a;
+ }
+ }
+
+ return '';
+}
+
+
+
+
\ No newline at end of file
diff --git a/library/asn1.php b/library/asn1.php
index 132b032480..713978e8c1 100644
--- a/library/asn1.php
+++ b/library/asn1.php
@@ -186,7 +186,7 @@ class ASN_BASE {
case ASN_BOOLEAN:
return new ASN_BOOLEAN((bool)$data);
case ASN_INTEGER:
- return new ASN_INTEGER(strtr(base64_encode($data),'+/=','-_,'));
+ return new ASN_INTEGER(strtr(base64_encode($data),'+/','-_'));
// return new ASN_INTEGER(ord($data));
case ASN_BIT_STR:
return new ASN_BIT_STR(self::parseASNString($data, $level+1, $maxLevels));
diff --git a/mod/salmon.php b/mod/salmon.php
index d68c746584..7ae29aafe2 100644
--- a/mod/salmon.php
+++ b/mod/salmon.php
@@ -1,5 +1,15 @@
<?php
+
+// TODO: pass keyhash to key discovery
+// add relevant contacts so they can use this
+
+// There is a lot of debug stuff in here because this is quite a
+// complicated process to try and sort out.
+
+require_once('include/salmon.php');
+require_once('simplepie/simplepie.inc');
+
function salmon_return($val) {
if($val >= 500)
@@ -18,7 +28,7 @@ function salmon_post(&$a) {
$debugging = get_config('system','debugging');
if($debugging)
- file_put_contents('salmon.out',$xml,FILE_APPEND);
+ file_put_contents('salmon.out','New Salmon: ' . $xml . "\n",FILE_APPEND);
$nick = (($a->argc > 1) ? notags(trim($a->argv[1])) : '');
$mentions = (($a->argc > 2 && $a->argv[2] === 'mention') ? true : false);
@@ -31,22 +41,168 @@ function salmon_post(&$a) {
$importer = $r[0];
- require_once('include/items.php');
+ // parse the xml
+
+ $dom = simplexml_load_string($xml,'SimpleXMLElement',0,NAMESPACE_SALMON_ME);
+
+
+ if($debugging)
+ file_put_contents('salmon.out', "\n" . print_r($dom,true) . "\n" , FILE_APPEND);
+
+ // figure out where in the DOM tree our data is hiding
+
+ if($dom->provenance->data)
+ $base = $dom->provenance;
+ elseif($dom->env->data)
+ $base = $dom->env;
+ elseif($dom->data)
+ $base = $dom;
+
+ if(! $base) {
+ if($debugging)
+ file_put_contents('salmon.out', "\n" . 'Unable to find salmon data in XML' . "\n" , FILE_APPEND);
+ salmon_return(500);
+ }
+
+ // Stash the signature away for now. We have to find their key or it won't be good for anything.
+
+
+ $signature = base64url_decode($base->sig);
+ if($debugging)
+ file_put_contents('salmon.out', "\n" . 'Encoded Signature: ' . $base->sig . "\n" , FILE_APPEND);
+
+ // unpack our data element.
+
+ // strip whitespace
+ $data = str_replace(array(" ","\t","\r","\n"),array("","","",""),$base->data);
+ $type = $base->data[0]->attributes()->type[0];
+ $encoding = $base->encoding;
+ $alg = $base->alg;
+
+ $signed_data = $data;
+ // . '.' . base64url_encode($type) . '.' . base64url_encode($encoding) . '.' . base64url_encode($alg);
+ // decode it
+ $data = base64url_decode($data);
+
+ if($debugging)
+ file_put_contents('salmon.out', "\n" . 'Signed data:>>>' . $signed_data . "<<<\n" , FILE_APPEND);
+
+ // Remove the xml declaration
+ $data = preg_replace('/\<\?xml[^\?].*\?\>/','',$data);
// Create a fake feed wrapper so simplepie doesn't choke
- $tpl = load_view_file('view/atom_feed.tpl');
+ $tpl = load_view_file('view/fake_feed.tpl');
- $base = substr($xml,strpos($xml,'<entry'));
+ $base = substr($data,strpos($data,'<entry'));
- $xml = $tpl . $base . '</feed>';
+ $feedxml = $tpl . $base . '</feed>';
-salmon_return(500); // until the handler is finished
+ if($debugging) {
+ file_put_contents('salmon.out', 'Processed feed: ' . $feedxml . "\n", FILE_APPEND);
+ }
-// consume_salmon($xml,$importer);
+ // Now parse it like a normal atom feed to scrape out the author URI
+
+ $feed = new SimplePie();
+ $feed->set_raw_data($feedxml);
+ $feed->enable_order_by_date(false);
+ $feed->init();
+
+ if($debugging) {
+ file_put_contents('salmon.out', "\n" . 'Feed parsed.' . "\n", FILE_APPEND);
+ }
+
+
+ if($feed->get_item_quantity()) {
+ foreach($feed->get_items() as $item) {
+ $author = $item->get_author();
+ $author_link = unxmlify($author->get_link());
+ break;
+ }
+ }
+
+ if(! $author_link) {
+ if($debugging)
+ file_put_contents('salmon.out',"\n" . 'Could not retrieve author URI.' . "\n", FILE_APPEND);
+ salmon_return(500);
+ }
+
+ // Once we have the author URI, go to the web and find their public key
+
+ if($debugging) {
+ file_put_contents('salmon.out', "\n" . 'Fetching key for ' . $author_link . "\n", FILE_APPEND);
+ }
+
+ $key = get_salmon_key($author_link,$keyhash);
+
+ if(! $key) {
+ if($debugging)
+ file_put_contents('salmon.out',"\n" . 'Could not retrieve author key.' . "\n", FILE_APPEND);
+ salmon_return(500);
+ }
+
+ // Setup RSA stuff to verify the signature
+
+ set_include_path(get_include_path() . PATH_SEPARATOR . 'phpsec');
+
+ require_once('phpsec/Crypt/RSA.php');
+
+ $key_info = explode('.',$key);
+
+ $m = base64url_decode($key_info[1]);
+ $e = base64url_decode($key_info[2]);
+ if($debugging)
+ file_put_contents('salmon.out',"\n" . print_r($key_info,true) . "\n", FILE_APPEND);
+
+ $rsa = new CRYPT_RSA();
+ $rsa->signatureMode = CRYPT_RSA_SIGNATURE_PKCS1;
+ $rsa->setHash('sha256');
+
+ $rsa->modulus = new Math_BigInteger($m, 256);
+ $rsa->k = strlen($rsa->modulus->toBytes());
+ $rsa->exponent = new Math_BigInteger($e, 256);
+
+ // We should have everything we need now. Let's see if it verifies.
+
+ $verify = $rsa->verify($signed_data,$signature);
+
+ if(! $verify) {
+ if($debugging)
+ file_put_contents('salmon.out',"\n" . 'Message did not verify. Discarding.' . "\n", FILE_APPEND);
+ salmon_return(500);
+ }
+
+ if($debugging)
+ file_put_contents('salmon.out',"\n" . 'Message verified.' . "\n", FILE_APPEND);
+
+
+ /*
+ *
+ * If we reached this point, the message is good. Now let's figure out if the author is allowed to send us stuff.
+ *
+ */
+
+ $r = q("SELECT * FROM `contact` WHERE `network` = 'stat' AND `lrdd` = '%s' AND `uid` = %d LIMIT 1",
+ dbesc($author_link),
+ intval($importer['uid'])
+ );
+ if(! count($r)) {
+ if($debugging)
+ file_put_contents('salmon.out',"\n" . 'Author unknown to us.' . "\n", FILE_APPEND);
+ salmon_return(500);
+ }
+
+
+ require_once('include/items.php');
+
+ $hub = '';
+
+ consume_feed($feedxml,$importer,$r[0],$hub);
salmon_return(200);
}
+
diff --git a/update.php b/update.php
index 3785cad2b2..65713583b3 100644
--- a/update.php
+++ b/update.php
@@ -75,4 +75,8 @@ function update_1008() {
function update_1009() {
q("ALTER TABLE `user` ADD `allow_location` TINYINT( 1 ) NOT NULL DEFAULT '0' AFTER `default-location` ");
-}
\ No newline at end of file
+}
+
+function update_1010() {
+ q("ALTER TABLE `contact` ADD `lrdd` CHAR( 255 ) NOT NULL AFTER `url` ");
+}
diff --git a/view/fake_feed.tpl b/view/fake_feed.tpl
new file mode 100644
index 0000000000..49b17e34da
--- /dev/null
+++ b/view/fake_feed.tpl
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<feed xmlns="http://www.w3.org/2005/Atom"
+ xmlns:thr="http://purl.org/syndication/thread/1.0"
+ xmlns:at="http://purl.org/atompub/tombstones/1.0"
+ xmlns:media="http://purl.org/syndication/atommedia"
+ xmlns:dfrn="http://purl.org/macgirvin/dfrn/1.0"
+ xmlns:as="http://activitystrea.ms/spec/1.0/"
+ xmlns:georss="http://www.georss.org/georss" >
+
+ <id>fake feed</id>
+ <title>fake title</title>
+
+ <updated>1970-01-01T00:00:00Z</updated>
+
+ <author>
+ <name>Fake Name</name>
+ <uri>http://example.com</uri>
+ </author>