1 files changed, 204 insertions, 0 deletions
diff --git a/trunk/etherpad/src/etherpad/collab/server_utils.js b/trunk/etherpad/src/etherpad/collab/server_utils.js
new file mode 100644
index 0000000..ece3aea
--- /dev/null
+++ b/trunk/etherpad/src/etherpad/collab/server_utils.js
@@ -0,0 +1,204 @@
+/**
+ * Copyright 2009 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS-IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import("comet");
+import("ejs");
+import("etherpad.collab.ace.easysync2.{AttribPool,Changeset}");
+import("etherpad.log");
+import("etherpad.pad.activepads");
+import("etherpad.pad.model");
+import("etherpad.pad.padutils");
+import("etherpad.pad.padevents");
+import("etherpad.pro.pro_padmeta");
+import("fastJSON");
+import("fileutils.readFile");
+import("jsutils.eachProperty");
+
+jimport("java.util.Random");
+jimport("java.lang.System");
+
+import("etherpad.collab.collab_server");
+// importClass(java.util.Random);
+// importClass(java.lang.System);
+
+var _serverDebug = function() {};
+var _dmesg = function() { System.out.println(arguments[0]+""); };
+
+/// Begin readonly/padId conversion code
+/// TODO: refactor into new file?
+var _baseRandomNumber = 0x123123; // keep this number seekrit
+
+function _map(array, func) {
+  for(var i=0; i<array.length; i++) {
+    array[i] = func(array[i]);
+  }
+  return array;
+}
+
+function parseUrlId(readOnlyIdOrLocalPadId) {
+  var localPadId;
+  var viewId;
+  var isReadOnly;
+  var roPadId;
+  var globalPadId;
+  if(isReadOnlyId(readOnlyIdOrLocalPadId)) {
+    isReadOnly = true;
+    globalPadId = readonlyToPadId(readOnlyIdOrLocalPadId);
+    localPadId = padutils.globalToLocalId(globalPadId);
+    var globalPadIdCheck = padutils.getGlobalPadId(localPadId);
+    if (globalPadId != globalPadIdCheck) {
+      // domain doesn't match
+      response.forbid();
+    }
+    roPadId = readOnlyIdOrLocalPadId;
+    viewId = roPadId;
+  }
+  else {
+    isReadOnly = false;
+    localPadId = readOnlyIdOrLocalPadId;
+    globalPadId = padutils.getGlobalPadId(localPadId);
+    viewId = globalPadId;
+    roPadId = padIdToReadonly(globalPadId);
+  }
+
+  return {localPadId:localPadId, viewId:viewId, isReadOnly:isReadOnly,
+          roPadId:roPadId, globalPadId:globalPadId};
+}
+
+function isReadOnlyId(str) {
+  return str.indexOf("ro.") == 0;
+}
+
+/*
+  for now, we just make it 'hard to guess'
+  TODO: make it impossible to find read/write page through hash
+*/
+function readonlyToPadId (readOnlyHash) {
+
+  // readOnly hashes must start with 'ro-'
+  if(!isReadOnlyId(readOnlyHash)) return null;
+  else {
+    readOnlyHash = readOnlyHash.substring(3, readOnlyHash.length);
+  }
+
+  // convert string to series of numbers between 1 and 64
+  var result = _strToArray(readOnlyHash);
+
+  var sum = result.pop();
+  // using a secret seed to util.random, transform each number using + and %
+  var seed = _baseRandomNumber + sum;
+  var rand = new Random(seed);
+
+  _map(result, function(elem) {
+    return ((64 + elem - rand.nextInt(64)) % 64);
+  });
+
+  // convert array of numbers back to a string
+  return _arrayToStr(result);
+}
+
+/*
+ Temporary code. see comment at readonlyToPadId.
+*/
+function padIdToReadonly (padid) {
+  var result = _strToArray(padid);
+  var sum = 0;
+
+  if(padid.length > 1) {
+    for(var i=0; i<result.length; i++) {
+      sum = (sum + result[i] + 1) % 64;
+    }
+  } else {
+    sum = 64;
+  }
+
+  var seed = _baseRandomNumber + sum;
+  var rand = new Random(seed);
+
+  _map(result, function(elem) {
+    var randnum = rand.nextInt(64);
+    return ((elem + randnum) % 64);
+  });
+
+  result.push(sum);
+  return "ro." + _arrayToStr(result);
+}
+
+// little reversable string encoding function
+// 0-9 are the numbers 0-9
+// 10-35 are the uppercase letters A-Z
+// 36-61 are the lowercase letters a-z
+// 62 are all other characters
+function _strToArray(str) {
+  var result = new Array(str.length);
+  for(var i=0; i<str.length; i++) {
+    result[i] = str.charCodeAt(i);
+
+    if (_between(result[i], '0'.charCodeAt(0), '9'.charCodeAt(0))) {
+      result[i] -= '0'.charCodeAt(0);
+    }
+    else if(_between(result[i], 'A'.charCodeAt(0), 'Z'.charCodeAt(0))) {
+      result[i] -= 'A'.charCodeAt(0); // A becomes 0
+      result[i] += 10;                // A becomes 10
+    }
+    else if(_between(result[i], 'a'.charCodeAt(0), 'z'.charCodeAt(0))) {
+      result[i] -= 'a'.charCodeAt(0); // a becomes 0
+      result[i] += 36;                // a becomes 36
+    } else if(result[i] == '$'.charCodeAt(0)) {
+      result[i] = 62;
+    } else {
+      result[i] = 63; // if not alphanumeric or $, we default to 63
+    }
+  }
+  return result;
+}
+
+function _arrayToStr(array) {
+  var result = "";
+  for(var i=0; i<array.length; i++) {
+    if(_between(array[i], 0, 9)) {
+      result += String.fromCharCode(array[i] + '0'.charCodeAt(0));
+    }
+    else if(_between(array[i], 10, 35)) {
+      result += String.fromCharCode(array[i] - 10 + 'A'.charCodeAt(0));
+    }
+    else if(_between(array[i], 36, 61)) {
+      result += String.fromCharCode(array[i] - 36 + 'a'.charCodeAt(0));
+    }
+    else if(array[i] == 62) {
+      result += "$";
+    } else {
+      result += "-";
+    }
+  }
+  return result;
+}
+
+function _between(charcode, start, end) {
+  return charcode >= start && charcode <= end;
+}
+
+/* a short little testing function, converts back and forth */
+// function _testEncrypt(str) {
+//   var encrypted = padIdToReadonly(str);
+//   var decrypted = readonlyToPadId(encrypted);
+//   _dmesg(str + " " + encrypted + " " + decrypted);
+//   if(decrypted != str) {
+//     _dmesg("ERROR: " + str + " and " + decrypted + " do not match");
+//   }
+// }
+
+// _testEncrypt("testing$");