From 9b2bc1af9c717e8a98b8e6c1bf9696b8059366e2 Mon Sep 17 00:00:00 2001
From: Scott Ullrich <sullrich@pfsense.org>
Date: Tue, 9 Nov 2010 11:23:49 -0500
Subject: Testing csrf-magic

---
 usr/local/www/csrf/csrf-magic.js  | 177 ++++++++++++++++++
 usr/local/www/csrf/csrf-magic.php | 372 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 549 insertions(+)
 create mode 100644 usr/local/www/csrf/csrf-magic.js
 create mode 100644 usr/local/www/csrf/csrf-magic.php

(limited to 'usr/local')

diff --git a/usr/local/www/csrf/csrf-magic.js b/usr/local/www/csrf/csrf-magic.js
new file mode 100644
index 0000000..820f6e8
--- /dev/null
+++ b/usr/local/www/csrf/csrf-magic.js
@@ -0,0 +1,177 @@
+/**
+ * @file
+ *
+ * Rewrites XMLHttpRequest to automatically send CSRF token with it. In theory
+ * plays nice with other JavaScript libraries, needs testing though.
+ */
+
+// Here are the basic overloaded method definitions
+// The wrapper must be set BEFORE onreadystatechange is written to, since
+// a bug in ActiveXObject prevents us from properly testing for it.
+CsrfMagic = function(real) {
+    // try to make it ourselves, if you didn't pass it
+    if (!real) try { real = new XMLHttpRequest; } catch (e) {;}
+    if (!real) try { real = new ActiveXObject('Msxml2.XMLHTTP'); } catch (e) {;}
+    if (!real) try { real = new ActiveXObject('Microsoft.XMLHTTP'); } catch (e) {;}
+    if (!real) try { real = new ActiveXObject('Msxml2.XMLHTTP.4.0'); } catch (e) {;}
+    this.csrf = real;
+    // properties
+    var csrfMagic = this;
+    real.onreadystatechange = function() {
+        csrfMagic._updateProps();
+        return csrfMagic.onreadystatechange ? csrfMagic.onreadystatechange() : null;
+    };
+    csrfMagic._updateProps();
+}
+
+CsrfMagic.prototype = {
+
+    open: function(method, url, async, username, password) {
+        if (method == 'POST') this.csrf_isPost = true;
+        // deal with Opera bug, thanks jQuery
+        if (username) return this.csrf_open(method, url, async, username, password);
+        else return this.csrf_open(method, url, async);
+    },
+    csrf_open: function(method, url, async, username, password) {
+        if (username) return this.csrf.open(method, url, async, username, password);
+        else return this.csrf.open(method, url, async);
+    },
+
+    send: function(data) {
+        if (!this.csrf_isPost) return this.csrf_send(data);
+        prepend = csrfMagicName + '=' + csrfMagicToken + '&';
+        if (this.csrf_purportedLength === undefined) {
+            this.csrf_setRequestHeader("Content-length", this.csrf_purportedLength + prepend.length);
+            delete this.csrf_purportedLength;
+        }
+        delete this.csrf_isPost;
+        return this.csrf_send(prepend + data);
+    },
+    csrf_send: function(data) {
+        return this.csrf.send(data);
+    },
+
+    setRequestHeader: function(header, value) {
+        // We have to auto-set this at the end, since we don't know how long the
+        // nonce is when added to the data.
+        if (this.csrf_isPost && header == "Content-length") {
+            this.csrf_purportedLength = value;
+            return;
+        }
+        return this.csrf_setRequestHeader(header, value);
+    },
+    csrf_setRequestHeader: function(header, value) {
+        return this.csrf.setRequestHeader(header, value);
+    },
+
+    abort: function() {
+        return this.csrf.abort();
+    },
+    getAllResponseHeaders: function() {
+        return this.csrf.getAllResponseHeaders();
+    },
+    getResponseHeader: function(header) {
+        return this.csrf.getResponseHeader(header);
+    } // ,
+}
+
+// proprietary
+CsrfMagic.prototype._updateProps = function() {
+    this.readyState = this.csrf.readyState;
+    if (this.readyState == 4) {
+        this.responseText = this.csrf.responseText;
+        this.responseXML  = this.csrf.responseXML;
+        this.status       = this.csrf.status;
+        this.statusText   = this.csrf.statusText;
+    }
+}
+CsrfMagic.process = function(base) {
+    var prepend = csrfMagicName + '=' + csrfMagicToken;
+    if (base) return prepend + '&' + base;
+    return prepend;
+}
+// callback function for when everything on the page has loaded
+CsrfMagic.end = function() {
+    // This rewrites forms AGAIN, so in case buffering didn't work this
+    // certainly will.
+    forms = document.getElementsByTagName('form');
+    for (var i = 0; i < forms.length; i++) {
+        form = forms[i];
+        if (form.method.toUpperCase() !== 'POST') continue;
+        if (form.elements[csrfMagicName]) continue;
+        var input = document.createElement('input');
+        input.setAttribute('name',  csrfMagicName);
+        input.setAttribute('value', csrfMagicToken);
+        input.setAttribute('type',  'hidden');
+        form.appendChild(input);
+    }
+}
+
+// Sets things up for Mozilla/Opera/nice browsers
+if (window.XMLHttpRequest && window.XMLHttpRequest.prototype) {
+    var x = XMLHttpRequest.prototype;
+    var c = CsrfMagic.prototype;
+
+    // Save the original functions
+    x.csrf_open = x.open;
+    x.csrf_send = x.send;
+    x.csrf_setRequestHeader = x.setRequestHeader;
+
+    // Notice that CsrfMagic is itself an instantiatable object, but only
+    // open, send and setRequestHeader are necessary as decorators.
+    x.open = c.open;
+    x.send = c.send;
+    x.setRequestHeader = c.setRequestHeader;
+} else {
+    // The only way we can do this is by modifying a library you have been
+    // using. We support YUI, script.aculo.us, prototype, MooTools,
+    // jQuery, Ext and Dojo.
+    if (window.jQuery) {
+        // jQuery didn't implement a new XMLHttpRequest function, so we have
+        // to do this the hard way.
+        jQuery.csrf_ajax = jQuery.ajax;
+        jQuery.ajax = function( s ) {
+            if (s.type && s.type.toUpperCase() == 'POST') {
+                s = jQuery.extend(true, s, jQuery.extend(true, {}, jQuery.ajaxSettings, s));
+                if ( s.data && s.processData && typeof s.data != "string" ) {
+                    s.data = jQuery.param(s.data);
+                }
+                s.data = CsrfMagic.process(s.data);
+            }
+            return jQuery.csrf_ajax( s );
+        }
+    } else if (window.Prototype) {
+        // This works for script.aculo.us too
+        Ajax.csrf_getTransport = Ajax.getTransport;
+        Ajax.getTransport = function() {
+            return new CsrfMagic(Ajax.csrf_getTransport());
+        }
+    } else if (window.MooTools) {
+        Browser.csrf_Request = Browser.Request;
+        Browser.Request = function () {
+            return new CsrfMagic(Browser.csrf_Request());
+        }
+    } else if (window.YAHOO) {
+        YAHOO.util.Connect.csrf_createXhrObject = YAHOO.util.Connect.createXhrObject;
+        YAHOO.util.Connect.createXhrObject = function (transaction) {
+            obj = YAHOO.util.Connect.csrf_createXhrObject(transaction);
+            obj.conn = new CsrfMagic(obj.conn);
+            return obj;
+        }
+    } else if (window.Ext) {
+        // Ext can use other js libraries as loaders, so it has to come last
+        // Ext's implementation is pretty identical to Yahoo's, but we duplicate
+        // it for comprehensiveness's sake.
+        Ext.lib.Ajax.csrf_createXhrObject = Ext.lib.Ajax.createXhrObject;
+        Ext.lib.Ajax.createXhrObject = function (transaction) {
+            obj = Ext.lib.Ajax.csrf_createXhrObject(transaction);
+            obj.conn = new CsrfMagic(obj.conn);
+            return obj;
+        }
+    } else if (window.dojo) {
+        dojo.csrf__xhrObj = dojo._xhrObj;
+        dojo._xhrObj = function () {
+            return new CsrfMagic(dojo.csrf__xhrObj());
+        }
+    }
+}
diff --git a/usr/local/www/csrf/csrf-magic.php b/usr/local/www/csrf/csrf-magic.php
new file mode 100644
index 0000000..447ecc9
--- /dev/null
+++ b/usr/local/www/csrf/csrf-magic.php
@@ -0,0 +1,372 @@
+<?php
+
+/**
+ * @file
+ *
+ * csrf-magic is a PHP library that makes adding CSRF-protection to your
+ * web applications a snap. No need to modify every form or create a database
+ * of valid nonces; just include this file at the top of every
+ * web-accessible page (or even better, your common include file included
+ * in every page), and forget about it! (There are, of course, configuration
+ * options for advanced users).
+ *
+ * This library is PHP4 and PHP5 compatible.
+ */
+
+// CONFIGURATION:
+
+/**
+ * By default, when you include this file csrf-magic will automatically check
+ * and exit if the CSRF token is invalid. This will defer executing
+ * csrf_check() until you're ready.  You can also pass false as a parameter to
+ * that function, in which case the function will not exit but instead return
+ * a boolean false if the CSRF check failed. This allows for tighter integration
+ * with your system.
+ */
+$GLOBALS['csrf']['defer'] = false;
+
+/**
+ * This is the amount of seconds you wish to allow before any token becomes
+ * invalid; the default is two hours, which should be more than enough for
+ * most websites.
+ */
+$GLOBALS['csrf']['expires'] = 7200;
+
+/**
+ * Callback function to execute when there's the CSRF check fails and
+ * $fatal == true (see csrf_check). This will usually output an error message
+ * about the failure.
+ */
+$GLOBALS['csrf']['callback'] = 'csrf_callback';
+
+/**
+ * Whether or not to include our JavaScript library which also rewrites
+ * AJAX requests on this domain. Set this to the web path. This setting only works
+ * with supported JavaScript libraries in Internet Explorer; see README.txt for
+ * a list of supported libraries.
+ */
+$GLOBALS['csrf']['rewrite-js'] = false;
+
+/**
+ * A secret key used when hashing items. Please generate a random string and
+ * place it here. If you change this value, all previously generated tokens
+ * will become invalid.
+ */
+$GLOBALS['csrf']['secret'] = '';
+
+/**
+ * Set this to false to disable csrf-magic's output handler, and therefore,
+ * its rewriting capabilities. If you're serving non HTML content, you should
+ * definitely set this false.
+ */
+$GLOBALS['csrf']['rewrite'] = true;
+
+/**
+ * Whether or not to use IP addresses when binding a user to a token. This is
+ * less reliable and less secure than sessions, but is useful when you need
+ * to give facilities to anonymous users and do not wish to maintain a database
+ * of valid keys.
+ */
+$GLOBALS['csrf']['allow-ip'] = true;
+
+/**
+ * If this information is available, use the cookie by this name to determine
+ * whether or not to allow the request. This is a shortcut implementation
+ * very similar to 'key', but we randomly set the cookie ourselves.
+ */
+$GLOBALS['csrf']['cookie'] = '__csrf_cookie';
+
+/**
+ * If this information is available, set this to a unique identifier (it
+ * can be an integer or a unique username) for the current "user" of this
+ * application. The token will then be globally valid for all of that user's
+ * operations, but no one else. This requires that 'secret' be set.
+ */
+$GLOBALS['csrf']['user'] = false;
+
+/**
+ * This is an arbitrary secret value associated with the user's session. This
+ * will most probably be the contents of a cookie, as an attacker cannot easily
+ * determine this information. Warning: If the attacker knows this value, they
+ * can easily spoof a token. This is a generic implementation; sessions should
+ * work in most cases.
+ *
+ * Why would you want to use this? Lets suppose you have a squid cache for your
+ * website, and the presence of a session cookie bypasses it. Let's also say
+ * you allow anonymous users to interact with the website; submitting forms
+ * and AJAX. Previously, you didn't have any CSRF protection for anonymous users
+ * and so they never got sessions; you don't want to start using sessions either,
+ * otherwise you'll bypass the Squid cache. Setup a different cookie for CSRF
+ * tokens, and have Squid ignore that cookie for get requests, for anonymous
+ * users. (If you haven't guessed, this scheme was(?) used for MediaWiki).
+ */
+$GLOBALS['csrf']['key'] = false;
+
+/**
+ * The name of the magic CSRF token that will be placed in all forms, i.e.
+ * the contents of <input type="hidden" name="$name" value="CSRF-TOKEN" />
+ */
+$GLOBALS['csrf']['input-name'] = '__csrf_magic';
+
+/**
+ * Set this to false if your site must work inside of frame/iframe elements,
+ * but do so at your own risk: this configuration protects you against CSS
+ * overlay attacks that defeat tokens.
+ */
+$GLOBALS['csrf']['frame-breaker'] = true;
+
+/**
+ * Whether or not CSRF Magic should be allowed to start a new session in order
+ * to determine the key.
+ */
+$GLOBALS['csrf']['auto-session'] = true;
+
+/**
+ * Whether or not csrf-magic should produce XHTML style tags.
+ */
+$GLOBALS['csrf']['xhtml'] = true;
+
+// FUNCTIONS:
+
+// Don't edit this!
+$GLOBALS['csrf']['version'] = '1.0.1';
+
+/**
+ * Rewrites <form> on the fly to add CSRF tokens to them. This can also
+ * inject our JavaScript library.
+ */
+function csrf_ob_handler($buffer, $flags) {
+    // Even though the user told us to rewrite, we should do a quick heuristic
+    // to check if the page is *actually* HTML. We don't begin rewriting until
+    // we hit the first <html tag.
+    static $is_html = false;
+    if (!$is_html) {
+        // not HTML until proven otherwise
+        if (stripos($buffer, '<html') !== false) {
+            $is_html = true;
+        } else {
+            return $buffer;
+        }
+    }
+    $tokens = csrf_get_tokens();
+    $name = $GLOBALS['csrf']['input-name'];
+    $endslash = $GLOBALS['csrf']['xhtml'] ? ' /' : '';
+    $input = "<input type='hidden' name='$name' value=\"$tokens\"$endslash>";
+    $buffer = preg_replace('#(<form[^>]*method\s*=\s*["\']post["\'][^>]*>)#i', '$1' . $input, $buffer);
+    if ($GLOBALS['csrf']['frame-breaker']) {
+        $buffer = str_ireplace('</head>', '<script type="text/javascript">if (top != self) {top.location.href = self.location.href;}</script></head>', $buffer);
+    }
+    if ($js = $GLOBALS['csrf']['rewrite-js']) {
+        $buffer = str_ireplace(
+            '</head>',
+            '<script type="text/javascript">'.
+                'var csrfMagicToken = "'.$tokens.'";'.
+                'var csrfMagicName = "'.$name.'";</script>'.
+            '<script src="'.$js.'" type="text/javascript"></script></head>',
+            $buffer
+        );
+        $script = '<script type="text/javascript">CsrfMagic.end();</script>';
+        $buffer = str_ireplace('</body>', $script . '</body>', $buffer, $count);
+        if (!$count) {
+            $buffer .= $script;
+        }
+    }
+    return $buffer;
+}
+
+/**
+ * Checks if this is a post request, and if it is, checks if the nonce is valid.
+ * @param bool $fatal Whether or not to fatally error out if there is a problem.
+ * @return True if check passes or is not necessary, false if failure.
+ */
+function csrf_check($fatal = true) {
+    if ($_SERVER['REQUEST_METHOD'] !== 'POST') return true;
+    csrf_start();
+    $name = $GLOBALS['csrf']['input-name'];
+    $ok = false;
+    $tokens = '';
+    do {
+        if (!isset($_POST[$name])) break;
+        // we don't regenerate a token and check it because some token creation
+        // schemes are volatile.
+        $tokens = $_POST[$name];
+        if (!csrf_check_tokens($tokens)) break;
+        $ok = true;
+    } while (false);
+    if ($fatal && !$ok) {
+        $callback = $GLOBALS['csrf']['callback'];
+        if (trim($tokens, 'A..Za..z0..9:;,') !== '') $tokens = 'hidden';
+        $callback($tokens);
+        exit;
+    }
+    return $ok;
+}
+
+/**
+ * Retrieves a valid token(s) for a particular context. Tokens are separated
+ * by semicolons.
+ */
+function csrf_get_tokens() {
+    $has_cookies = !empty($_COOKIE);
+
+    // $ip implements a composite key, which is sent if the user hasn't sent
+    // any cookies. It may or may not be used, depending on whether or not
+    // the cookies "stick"
+    if (!$has_cookies && $secret) {
+        // :TODO: Harden this against proxy-spoofing attacks
+        $ip = ';ip:' . csrf_hash($_SERVER['IP_ADDRESS']);
+    } else {
+        $ip = '';
+    }
+    csrf_start();
+
+    // These are "strong" algorithms that don't require per se a secret
+    if (session_id()) return 'sid:' . csrf_hash(session_id()) . $ip;
+    if ($GLOBALS['csrf']['cookie']) {
+        $val = csrf_generate_secret();
+        setcookie($GLOBALS['csrf']['cookie'], $val);
+        return 'cookie:' . csrf_hash($val) . $ip;
+    }
+    if ($GLOBALS['csrf']['key']) return 'key:' . csrf_hash($GLOBALS['csrf']['key']) . $ip;
+    // These further algorithms require a server-side secret
+    if ($secret === '') return 'invalid';
+    if ($GLOBALS['csrf']['user'] !== false) {
+        return 'user:' . csrf_hash($GLOBALS['csrf']['user']);
+    }
+    if ($GLOBALS['csrf']['allow-ip']) {
+        return ltrim($ip, ';');
+    }
+    return 'invalid';
+}
+
+/**
+ * @param $tokens is safe for HTML consumption
+ */
+function csrf_callback($tokens) {
+    header($_SERVER['SERVER_PROTOCOL'] . ' 403 Forbidden');
+    echo "<html><head><title>CSRF check failed</title></head><body>CSRF check failed. Please enable cookies.<br />Debug: ".$tokens."</body></html>
+";
+}
+
+/**
+ * Checks if a composite token is valid. Outward facing code should use this
+ * instead of csrf_check_token()
+ */
+function csrf_check_tokens($tokens) {
+    if (is_string($tokens)) $tokens = explode(';', $tokens);
+    foreach ($tokens as $token) {
+        if (csrf_check_token($token)) return true;
+    }
+    return false;
+}
+
+/**
+ * Checks if a token is valid.
+ */
+function csrf_check_token($token) {
+    if (strpos($token, ':') === false) return false;
+    list($type, $value) = explode(':', $token, 2);
+    if (strpos($value, ',') === false) return false;
+    list($x, $time) = explode(',', $token, 2);
+    if ($GLOBALS['csrf']['expires']) {
+        if (time() > $time + $GLOBALS['csrf']['expires']) return false;
+    }
+    switch ($type) {
+        case 'sid':
+            return $value === csrf_hash(session_id(), $time);
+        case 'cookie':
+            $n = $GLOBALS['csrf']['cookie'];
+            if (!$n) return false;
+            if (!isset($_COOKIE[$n])) return false;
+            return $value === csrf_hash($_COOKIE[$n], $time);
+        case 'key':
+            if (!$GLOBALS['csrf']['key']) return false;
+            return $value === csrf_hash($GLOBALS['csrf']['key'], $time);
+        // We could disable these 'weaker' checks if 'key' was set, but
+        // that doesn't make me feel good then about the cookie-based
+        // implementation.
+        case 'user':
+            if ($GLOBALS['csrf']['secret'] === '') return false;
+            if ($GLOBALS['csrf']['user'] === false) return false;
+            return $value === csrf_hash($GLOBALS['csrf']['user'], $time);
+        case 'ip':
+            if (csrf_get_secret() === '') return false;
+            // do not allow IP-based checks if the username is set, or if
+            // the browser sent cookies
+            if ($GLOBALS['csrf']['user'] !== false) return false;
+            if (!empty($_COOKIE)) return false;
+            if (!$GLOBALS['csrf']['allow-ip']) return false;
+            return $value === csrf_hash($_SERVER['IP_ADDRESS'], $time);
+    }
+    return false;
+}
+
+/**
+ * Sets a configuration value.
+ */
+function csrf_conf($key, $val) {
+    if (!isset($GLOBALS['csrf'][$key])) {
+        trigger_error('No such configuration ' . $key, E_USER_WARNING);
+        return;
+    }
+    $GLOBALS['csrf'][$key] = $val;
+}
+
+/**
+ * Starts a session if we're allowed to.
+ */
+function csrf_start() {
+    if ($GLOBALS['csrf']['auto-session'] && !session_id()) {
+        session_start();
+    }
+}
+
+/**
+ * Retrieves the secret, and generates one if necessary.
+ */
+function csrf_get_secret() {
+    if ($GLOBALS['csrf']['secret']) return $GLOBALS['csrf']['secret'];
+    $dir = dirname(__FILE__);
+    $file = $dir . '/csrf-secret.php';
+    $secret = '';
+    if (file_exists($file)) {
+        include $file;
+        return $secret;
+    }
+    if (is_writable($dir)) {
+        $secret = csrf_generate_secret();
+        $fh = fopen($file, 'w');
+        fwrite($fh, '<?php $secret = "'.$secret.'";' . PHP_EOL);
+        fclose($fh);
+        return $secret;
+    }
+    return '';
+}
+
+/**
+ * Generates a random string as the hash of time, microtime, and mt_rand.
+ */
+function csrf_generate_secret($len = 32) {
+    $secret = '';
+    for ($i = 0; $i < 32; $i++) {
+        $secret .= chr(mt_rand(0, 255));
+    }
+    $secret .= time() . microtime();
+    return sha1($secret);
+}
+
+/**
+ * Generates a hash/expiry double. If time isn't set it will be calculated
+ * from the current time.
+ */
+function csrf_hash($value, $time = null) {
+    if (!$time) $time = time();
+    return sha1($secret . $value . $time) . ',' . $time;
+}
+
+// Load user configuration
+if (function_exists('csrf_startup')) csrf_startup();
+// Initialize our handler
+if ($GLOBALS['csrf']['rewrite'])     ob_start('csrf_ob_handler');
+// Perform check
+if (!$GLOBALS['csrf']['defer'])      csrf_check();
-- 
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