From b591115b724ee692674775d4ddd52d333fc9265b Mon Sep 17 00:00:00 2001
From: Andrew McMillan <debian@mcmillan.net.nz>
Date: Mon, 27 Nov 2006 00:16:01 +1300
Subject: [PATCH] New class to handle requests, so we can extract permissions
 in a better way.  Of course this breaks all of the existing code, so don't
 use this until I have all the regression tests passing again :-)

---
 dba/caldav_functions.sql |   2 +-
 htdocs/caldav.php        | 118 ++------------------
 inc/CalDAVRequest.php    | 227 +++++++++++++++++++++++++++++++++++++++
 rscds.webprj             |   5 +-
 4 files changed, 237 insertions(+), 115 deletions(-)
 create mode 100644 inc/CalDAVRequest.php

diff --git a/dba/caldav_functions.sql b/dba/caldav_functions.sql
index fe7535e1..717e5f73 100644
--- a/dba/caldav_functions.sql
+++ b/dba/caldav_functions.sql
@@ -207,7 +207,7 @@ DECLARE
 BEGIN
   -- Self can always have full access
   IF in_from = in_to THEN
-    RETURN ''RW'';
+    RETURN ''A'';
   END IF;
 
   -- dbg := ''S-'';
diff --git a/htdocs/caldav.php b/htdocs/caldav.php
index 50e6e8f7..d3d0943b 100644
--- a/htdocs/caldav.php
+++ b/htdocs/caldav.php
@@ -12,115 +12,10 @@ require_once("always.php");
 dbg_error_log( "caldav", " User agent: %s", ((isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : "Unfortunately Mulberry and Chandler don't send a 'User-agent' header with their requests :-(")) );
 require_once("BasicAuthSession.php");
 
-$raw_headers = apache_request_headers();
-$raw_post = file_get_contents ( 'php://input');
+require_once("CalDAVRequest.php");
+$request = new CalDAVRequest();
 
-if ( isset($debugging) && isset($_GET['method']) ) {
-  $_SERVER['REQUEST_METHOD'] = $_GET['method'];
-}
-
-/**
-* A variety of requests may set the "Depth" header to control recursion
-*/
-$query_depth = ( isset($_SERVER['HTTP_DEPTH']) ? $_SERVER['HTTP_DEPTH'] : 0 );
-if ( $query_depth == 'infinite' ) $query_depth = 99;
-$query_depth = intval($query_depth);
-
-/**
-* Our path is /<script name>/<user name>/<user controlled> if it ends in
-* a trailing '/' then it is referring to a DAV 'collection' but otherwise
-* it is referring to a DAV data item.
-*
-* Permissions are controlled as follows:
-*  1. if there is no <user name> component, the request has read privileges
-*  2. if the requester is an admin, the request has read/write priviliges
-*  3. if there is a <user name> component which matches the logged on user
-*     then the request has read/write privileges
-*  4. otherwise we query the defined relationships between users and use
-*     the minimum privileges returned from that analysis.
-*/
-$request_path = $_SERVER['PATH_INFO'];
-$bad_chars_regex = '/[\\^\\[\\(\\\\]/';
-if ( preg_match( $bad_chars_regex, $request_path ) ) {
-  header("HTTP/1.1 400 Bad Request");
-  header("Content-type: text/plain");
-  echo "The calendar path contains illegal characters.";
-  dbg_error_log("caldav", "Illegal characters /%s/ in calendar path for User: %d, Path: %s", $bad_chars_regex, $session->user_no, $request_path);
-  exit(0);
-}
-dbg_error_log("caldav", "Legal characters /%s/ in calendar path for User: %d, Path: %s", $bad_chars_regex, $session->user_no, $request_path);
-
-$path_split = preg_split('#/+#', $request_path );
-$permissions = array();
-if ( !isset($path_split[1]) || $path_split[1] == '' ) {
-  dbg_error_log( "caldav", "No useful path split possible" );
-  unset($path_user_no);
-  unset($path_username);
-  $permissions = array("read" => 'read' );
-  dbg_error_log( "caldav", "Read permissions for user accessing /" );
-}
-else {
-  $path_username = $path_split[1];
-  @dbg_error_log( "caldav", "Path split into at least /// %s /// %s /// %s", $path_split[1], $path_split[2], $path_split[3] );
-  $qry = new PgQuery( "SELECT * FROM usr WHERE username = ?;", $path_username );
-  if ( $qry->Exec("caldav") && $path_user_record = $qry->Fetch() ) {
-    $path_user_no = $path_user_record->user_no;
-  }
-  if ( $session->AllowedTo("Admin") ) {
-    $permissions = array('all' => 'all' );
-    dbg_error_log( "caldav", "Full permissions for a systems administrator" );
-  }
-  else if ( $session->user_no == $path_user_no ) {
-    $permissions = array('all' => 'all' );
-    dbg_error_log( "caldav", "Full permissions for user accessing their own hierarchy" );
-  }
-  else if ( isset($path_user_no) ) {
-    /**
-    * We need to query the database for permissions
-    */
-    $qry = new PgQuery( "SELECT get_permissions( ?, ? ) AS perm;", $session->user_no, $path_user_no);
-    if ( $qry->Exec("caldav") && $permission_result = $qry->Fetch() ) {
-      $permission_result = "!".$permission_result->perm; // We prepend something to ensure we get a non-zero position.
-      $permissions = array();
-      if ( strpos($permission_result,"R") )       $permissions['read'] = 'read';
-      if ( strpos($permission_result,"W") )
-        $permissions['write'] = 'write';
-      else {
-        if ( strpos($permission_result,"C") )       $permissions['bind'] = 'bind';      // PUT of new content (i.e. Create)
-        if ( strpos($permission_result,"D") )       $permissions['unbind'] = 'unbind';  // DELETE
-        if ( strpos($permission_result,"M") )       $permissions['write-content'] = 'write-content';  // DELETE
-      }
-    }
-    dbg_error_log( "caldav", "Restricted permissions for user accessing someone elses hierarchy: read=%s, write=%s", isset($permissions['read']), isset($permissions['write']) );
-  }
-}
-
-/**
-* If the content we are receiving is XML then we parse it here.
-*/
-$xml_parser = xml_parser_create_ns('UTF-8');
-$xml_tags = array();
-xml_parser_set_option ( $xml_parser, XML_OPTION_SKIP_WHITE, 1 );
-xml_parse_into_struct( $xml_parser, $raw_post, $xml_tags );
-xml_parser_free($xml_parser);
-
-unset($etag_if_match);
-unset($etag_none_match);
-if ( isset($_SERVER["HTTP_IF_NONE_MATCH"]) ) {
-  $etag_none_match = str_replace('"','',$_SERVER["HTTP_IF_NONE_MATCH"]);
-  if ( $etag_none_match == '' ) unset($etag_none_match);
-}
-if ( isset($_SERVER["HTTP_IF_MATCH"]) ) {
-  $etag_if_match = str_replace('"','',$_SERVER["HTTP_IF_MATCH"]);
-  if ( $etag_if_match == '' ) unset($etag_if_match);
-}
-
-
-/**
-* We put the code for each type of request into a separate include file
-*/
-$request_method = $_SERVER['REQUEST_METHOD'];
-switch ( $request_method ) {
+switch ( $request->method ) {
   case 'OPTIONS':    include_once("caldav-OPTIONS.php");    break;
   case 'REPORT':     include_once("caldav-REPORT.php");     break;
   case 'PROPFIND':   include_once("caldav-PROPFIND.php");   break;
@@ -133,12 +28,11 @@ switch ( $request_method ) {
   case 'DELETE':     include_once("caldav-DELETE.php");     break;
 
   default:
-    dbg_error_log( "caldav", "Unhandled request method >>%s<<", $_SERVER['REQUEST_METHOD'] );
-    dbg_log_array( "caldav", 'HEADERS', $raw_headers );
+    dbg_error_log( "caldav", "Unhandled request method >>%s<<", $request->method );
     dbg_log_array( "caldav", '_SERVER', $_SERVER, true );
-    dbg_error_log( "caldav", "RAW: %s", str_replace("\n", "",str_replace("\r", "", $raw_post)) );
+    dbg_error_log( "caldav", "RAW: %s", str_replace("\n", "",str_replace("\r", "", $request->raw_post)) );
 }
 
-exit(0);
+$this->RequestExitStatus( 500, translate("The application program does not understand that request.") );
 
 ?>
\ No newline at end of file
diff --git a/inc/CalDAVRequest.php b/inc/CalDAVRequest.php
new file mode 100644
index 00000000..2dc995cd
--- /dev/null
+++ b/inc/CalDAVRequest.php
@@ -0,0 +1,227 @@
+<?php
+/**
+* Functions that are needed for all CalDAV Requests
+*
+*  - Ascertaining the paths
+*  - Ascertaining the current user's permission to those paths.
+*  - Utility functions which we can use to decide whether this
+*    is a permitted activity for this user.
+*
+* @package   rscds
+* @subpackage   CalDAVRequest
+* @author    Andrew McMillan <andrew@mcmillan.net.nz>
+* @copyright Andrew McMillan
+* @license   http://gnu.org/copyleft/gpl.html GNU GPL v2
+*/
+
+/**
+* A class for collecting things to do with this request.
+*
+* @package   rscds
+*/
+class CalDAVRequest
+{
+
+  /**
+  * Create a new CalDAVRequest object.
+  */
+  function CalDAVRequest( ) {
+    global $session, $c, $debugging;
+
+    $this->raw_post = file_get_contents ( 'php://input');
+
+    if ( isset($debugging) && isset($_GET['method']) ) {
+      $_SERVER['REQUEST_METHOD'] = $_GET['method'];
+    }
+    $this->method = $_SERVER['REQUEST_METHOD'];
+
+    /**
+    * A variety of requests may set the "Depth" header to control recursion
+    */
+    $this->depth = ( isset($_SERVER['HTTP_DEPTH']) ? $_SERVER['HTTP_DEPTH'] : 0 );
+    if ( $this->depth == 'infinite' ) $this->depth = 99;
+    $this->depth = intval($this->depth);
+
+    /**
+    * Our path is /<script name>/<user name>/<user controlled> if it ends in
+    * a trailing '/' then it is referring to a DAV 'collection' but otherwise
+    * it is referring to a DAV data item.
+    *
+    * Permissions are controlled as follows:
+    *  1. if there is no <user name> component, the request has read privileges
+    *  2. if the requester is an admin, the request has read/write priviliges
+    *  3. if there is a <user name> component which matches the logged on user
+    *     then the request has read/write privileges
+    *  4. otherwise we query the defined relationships between users and use
+    *     the minimum privileges returned from that analysis.
+    */
+    $this->path = $_SERVER['PATH_INFO'];
+    $bad_chars_regex = '/[\\^\\[\\(\\\\]/';
+    if ( preg_match( $bad_chars_regex, $this->path ) ) {
+      $this->RequestExitStatus( 400, translate("The calendar path contains illegal characters.") );
+    }
+
+    $path_split = preg_split('#/+#', $this->path );
+    $this->permissions = array();
+    if ( !isset($path_split[1]) || $path_split[1] == '' ) {
+      dbg_error_log( "caldav", "No useful path split possible" );
+      unset($this->user_no);
+      unset($this->username);
+      $this->permissions = array("read" => 'read' );
+      dbg_error_log( "caldav", "Read permissions for user accessing /" );
+    }
+    else {
+      $this->username = $path_split[1];
+      @dbg_error_log( "caldav", "Path split into at least /// %s /// %s /// %s", $path_split[1], $path_split[2], $path_split[3] );
+      $qry = new PgQuery( "SELECT * FROM usr WHERE username = ?;", $this->username );
+      if ( $qry->Exec("caldav") && $user = $qry->Fetch() ) {
+        $this->user_no = $user->user_no;
+      }
+      if ( $session->AllowedTo("Admin") ) {
+        $this->permissions = array('all' => 'all' );
+        dbg_error_log( "caldav", "Full permissions for a systems administrator" );
+      }
+      else if ( $session->user_no == $this->user_no ) {
+        $this->permissions = array('all' => 'all' );
+        dbg_error_log( "caldav", "Full permissions for user accessing their own hierarchy" );
+      }
+      else if ( isset($this->user_no) ) {
+        /**
+        * We need to query the database for permissions
+        */
+        $qry = new PgQuery( "SELECT get_permissions( ?, ? ) AS perm;", $session->user_no, $this->user_no);
+        if ( $qry->Exec("caldav") && $permission_result = $qry->Fetch() ) {
+          $permission_result = "!".$permission_result->perm; // We prepend something to ensure we get a non-zero position.
+          $this->permissions = array();
+          if ( strpos($permission_result,"A") )
+            $this->permissions['all'] = 'all';
+          else {
+            if ( strpos($permission_result,"R") )       $this->permissions['read'] = 'read';
+            if ( strpos($permission_result,"W") )
+              $this->permissions['write'] = 'write';
+            else {
+              if ( strpos($permission_result,"C") )       $this->permissions['bind'] = 'bind';      // PUT of new content (i.e. Create)
+              if ( strpos($permission_result,"D") )       $this->permissions['unbind'] = 'unbind';  // DELETE
+              if ( strpos($permission_result,"M") )       $this->permissions['write-content'] = 'write-content';  // DELETE
+            }
+          }
+        }
+        dbg_error_log( "caldav", "Restricted permissions for user accessing someone elses hierarchy: %s", implode( ", ", $this->permissions ) );
+      }
+    }
+
+    /**
+    * If the content we are receiving is XML then we parse it here.
+    */
+    $xml_parser = xml_parser_create_ns('UTF-8');
+    $xml_tags = array();
+    xml_parser_set_option ( $xml_parser, XML_OPTION_SKIP_WHITE, 1 );
+    xml_parse_into_struct( $xml_parser, $raw_post, $xml_tags );
+    xml_parser_free($xml_parser);
+
+    if ( isset($_SERVER["HTTP_IF_NONE_MATCH"]) ) {
+      $this->etag_none_match = str_replace('"','',$_SERVER["HTTP_IF_NONE_MATCH"]);
+      if ( $this->etag_none_match == '' ) unset($this->etag_none_match);
+    }
+    if ( isset($_SERVER["HTTP_IF_MATCH"]) ) {
+      $this->etag_if_match = str_replace('"','',$_SERVER["HTTP_IF_MATCH"]);
+      if ( $this->etag_if_match == '' ) unset($this->etag_if_match);
+    }
+
+  }
+
+  /**
+  * Are we allowed to do the requested activity
+  *
+  * @param string $activity The activity we want to do.
+  */
+  function AllowedTo( $activity ) {
+    if ( isset($this->permissions['all']) ) return true;
+    switch( $activity ) {
+      case 'read':
+        return isset($this->permissions['read']);
+        break;
+      case 'write':
+        return isset($this->permissions['write']);
+        break;
+      case 'delete':
+        return isset($this->permissions['write']) || isset($this->permissions['unbind']);
+        break;
+      case 'create':
+        return isset($this->permissions['write']) || isset($this->permissions['bind']);
+        break;
+      case 'modify':
+        return isset($this->permissions['write']) || isset($this->permissions['write-content']);
+        break;
+      case 'mkcol':
+        return isset($this->permissions['write']);
+        break;
+    }
+
+    return false;
+  }
+
+
+  /**
+  * Utility function we call when we have a simple status-based response to
+  * return to the client.  Possibly
+  *
+  * @param int $status The HTTP status code to send.
+  * @param string $message The friendly text message to send with the response.
+  */
+  function RequestExitStatus( $status, $message, $content_type="text/plain" ) {
+    global $session, $c;
+    switch( $status ) {
+      case 100: $status_text = "Continue"; break;
+      case 101: $status_text = "Switching Protocols"; break;
+      case 200: $status_text = "OK"; break;
+      case 201: $status_text = "Created"; break;
+      case 202: $status_text = "Accepted"; break;
+      case 203: $status_text = "Non-Authoritative Information"; break;
+      case 204: $status_text = "No Content"; break;
+      case 205: $status_text = "Reset Content"; break;
+      case 206: $status_text = "Partial Content"; break;
+      case 207: $status_text = "Multi-Status"; break;
+      case 300: $status_text = "Multiple Choices"; break;
+      case 301: $status_text = "Moved Permanently"; break;
+      case 302: $status_text = "Found"; break;
+      case 303: $status_text = "See Other"; break;
+      case 304: $status_text = "Not Modified"; break;
+      case 305: $status_text = "Use Proxy"; break;
+      case 307: $status_text = "Temporary Redirect"; break;
+      case 400: $status_text = "Bad Request"; break;
+      case 401: $status_text = "Unauthorized"; break;
+      case 402: $status_text = "Payment Required"; break;
+      case 403: $status_text = "Forbidden"; break;
+      case 404: $status_text = "Not Found"; break;
+      case 405: $status_text = "Method Not Allowed"; break;
+      case 406: $status_text = "Not Acceptable"; break;
+      case 407: $status_text = "Proxy Authentication Required"; break;
+      case 408: $status_text = "Request Timeout"; break;
+      case 409: $status_text = "Conflict"; break;
+      case 410: $status_text = "Gone"; break;
+      case 411: $status_text = "Length Required"; break;
+      case 412: $status_text = "Precondition Failed"; break;
+      case 413: $status_text = "Request Entity Too Large"; break;
+      case 414: $status_text = "Request-URI Too Long"; break;
+      case 415: $status_text = "Unsupported Media Type"; break;
+      case 416: $status_text = "Requested Range Not Satisfiable"; break;
+      case 417: $status_text = "Expectation Failed"; break;
+      case 500: $status_text = "Internal Server Error"; break;
+      case 501: $status_text = "Not Implemented"; break;
+    }
+    header( sprintf("HTTP/1.1 %d %s", $status, $status_text) );
+    header( "Content-type: ".$content_type );
+    echo $message;
+
+    if ( strlen($message) > 100 || strstr($message, "\n") ) {
+      $message = substr( preg_replace("#\s+#m", ' ', $message ), 0, 100);
+    }
+
+    dbg_error_log("caldav", "Status: %d, Message: %s, User: %d, Path: %s", $status, $message, $session->user_no, $this->path);
+
+    exit(0);
+  }
+}
+
+?>
\ No newline at end of file
diff --git a/rscds.webprj b/rscds.webprj
index 734b60e4..265a8c74 100644
--- a/rscds.webprj
+++ b/rscds.webprj
@@ -223,7 +223,8 @@
     <item url="testing/tests/regression-suite/023-Mulberry-DELETE-3.test" uploadstatus="1" />
     <item url="testing/tests/regression-suite/022-Mulberry-PUT-5.test" uploadstatus="1" />
     <item url="dba/patches/1.1.5.sql" uploadstatus="1" />
-    <item url="docs/website/wikiheader.css" />
-    <item url="htdocs/collection.php" />
+    <item url="docs/website/wikiheader.css" uploadstatus="1" />
+    <item url="htdocs/collection.php" uploadstatus="1" />
+    <item url="inc/CalDAVRequest.php" />
   </project>
 </webproject>