Restore encrypted TiddlyWiki support

bld.sh

@@ -21,28 +21,35 @@ echo "Using TW5_BUILD_OUTPUT as [$TW5_BUILD_OUTPUT]"
 
 echo "five.tiddlywiki.com" > $TW5_BUILD_OUTPUT/CNAME
 
-# First, index.html: the main file, including content
+# First,
+#  readme.md: the readme file for GitHub
+#  index.html: the main file, including content
+#  static.html: the static version of the default tiddlers
+
+node ../../tiddlywiki.js \
+	--verbose \
+	--savetiddler ReadMe ../../readme.md text/html \
+	--savetiddler $:/core/templates/tiddlywiki5.template.html $TW5_BUILD_OUTPUT/index.html text/plain \
+	--savetiddler $:/core/templates/static.template.html $TW5_BUILD_OUTPUT/static.html text/plain \
+	|| exit 1
+
+# Second, encrypted.html: a version of the main file encrypted with the password "password"
 
 node ../../tiddlywiki.js \
 	--verbose \
 	--password password \
-	--savetiddler ReadMe ../../readme.md text/html \
-	--savetiddler $:/core/templates/tiddlywiki5.template.html $TW5_BUILD_OUTPUT/index.html text/plain \
-	--savetiddler $:/core/templates/tiddlywiki5.encrypted.template.html $TW5_BUILD_OUTPUT/encrypted.html text/plain \
-	--savetiddler $:/core/templates/static.template.html $TW5_BUILD_OUTPUT/static.html text/plain \
+	--savetiddler $:/core/templates/tiddlywiki5.template.html $TW5_BUILD_OUTPUT/encrypted.html text/plain \
 	|| exit 1
 
 popd > /dev/null
 
-# Second, empty.html: empty wiki for reuse
+# Third, empty.html: empty wiki for reuse
 
 pushd editions/empty > /dev/null
 
 node ../../tiddlywiki.js \
 	--verbose \
-	--password password \
 	--savetiddler $:/core/templates/tiddlywiki5.template.html $TW5_BUILD_OUTPUT/empty.html text/plain \
-	--savetiddler $:/core/templates/tiddlywiki5.encrypted.template.html $TW5_BUILD_OUTPUT/empty_encrypted.html text/plain \
 	|| exit 1
 
 popd > /dev/null

core/boot.js

@@ -358,7 +358,10 @@ $tw.utils.PasswordPrompt.prototype.createPrompt = function(options) {
 	this.setWrapperDisplay();
 };
 
-// Crypto helper object for encrypted content
+/*
+Crypto helper object for encrypted content. It maintains the password text in a closure, and provides methods to change
+the password, and to encrypt/decrypt a block of text
+*/
 $tw.utils.Crypto = function() {
 	var sjcl = $tw.browser ? window.sjcl : require("./sjcl.js"),
 		password = null,
@@ -374,7 +377,14 @@ $tw.utils.Crypto = function() {
 		};
 	this.setPassword = function(newPassword) {
 		password = newPassword;
+		this.updateCryptoStateTiddler();
 	};
+	this.updateCryptoStateTiddler = function() {
+		$tw.wiki.addTiddler(new $tw.Tiddler({title: "$:/isEncrypted", text: password ? "yes" : "no"}));
+	};
+	this.hasPassword = function() {
+		return !!password;
+	}
 	this.encrypt = function(text) {
 		return callSjcl("encrypt",text);
 	};
@@ -723,22 +733,13 @@ $tw.wiki = new $tw.Wiki();
 if($tw.browser) {
 
 /*
-Get any encrypted tiddlers
+Decrypt any tiddlers stored within the element with the ID "encryptedArea". The function is asynchronous to allow the user to be prompted for a password
+	callback: function to be called the decryption is complete
 */
 $tw.boot.decryptEncryptedTiddlers = function(callback) {
-	var encryptedArea = document.getElementById("encryptedArea"),
-		encryptedTiddlers = [];
+	var encryptedArea = document.getElementById("encryptedStoreArea");
 	if(encryptedArea) {
-		for(var t = 0; t <encryptedArea.childNodes.length; t++) {
-			var childNode = encryptedArea.childNodes[t];
-			if(childNode.hasAttribute && childNode.hasAttribute("data-tw-encrypted-tiddlers")) {
-				var e = childNode.firstChild;
-				while(e && e.nodeName.toLowerCase() !== "pre") {
-					e = e.nextSibling;
-				}
-				encryptedTiddlers.push($tw.utils.htmlDecode(e.innerHTML));
-			}
-		}
+		var encryptedText = encryptedArea.innerHTML;
 		// Prompt for the password
 		$tw.passwordPrompt.createPrompt({
 			serviceName: "Enter a password to decrypt this TiddlyWiki",
@@ -747,18 +748,12 @@ $tw.boot.decryptEncryptedTiddlers = function(callback) {
 			callback: function(data) {
 				// Attempt to decrypt the tiddlers
 				$tw.crypto.setPassword(data.password);
-				for(var t=encryptedTiddlers.length-1; t>=0; t--) {
-					var decrypted = $tw.crypto.decrypt(encryptedTiddlers[t]);
-					if(decrypted) {
-						var json = JSON.parse(decrypted);
-						for(var title in json) {
-							$tw.preloadTiddler(json[title]);
-						}
-						encryptedTiddlers.splice(t,1);
+				var decryptedText = $tw.crypto.decrypt(encryptedText);
+				if(decryptedText) {
+					var json = JSON.parse(decryptedText);
+					for(var title in json) {
+						$tw.preloadTiddler(json[title]);
 					}
-				}
-				// Check if we're all done
-				if(encryptedTiddlers.length === 0) {
 					// Call the callback
 					callback();
 					// Exit and remove the password prompt
@@ -770,7 +765,7 @@ $tw.boot.decryptEncryptedTiddlers = function(callback) {
 			}
 		});
 	} else {
-		// Just invoke the callback straight away if there wasn't any encrypted tiddlers
+		// Just invoke the callback straight away if there weren't any encrypted tiddlers
 		callback();
 	}
 };
@@ -1094,6 +1089,8 @@ $tw.boot.startup = function() {
 	$tw.wiki.defineTiddlerModules();
 	// And any modules within bundles
 	$tw.wiki.defineBundledModules();
+	// Make sure the crypto state tiddler is up to date
+	$tw.crypto.updateCryptoStateTiddler();
 	// Run any startup modules
 	$tw.modules.forEachModuleOfType("startup",function(title,module) {
 		if(module.startup) {

core/modules/startup.js

@@ -82,6 +82,21 @@ exports.startup = function() {
 				downloadType: "text/plain"
 			});
 		},false);
+		// Install the crypto event handler
+		document.addEventListener("tw-set-password",function(event) {
+			$tw.passwordPrompt.createPrompt({
+				serviceName: "Set new password for this TiddlyWiki",
+				noUserName: true,
+				submitText: "Set password",
+				callback: function(data) {
+					$tw.crypto.setPassword(data.password);
+					return true; // Get rid of the password prompt
+				}
+			});
+		});
+		document.addEventListener("tw-clear-password",function(event) {
+			$tw.crypto.setPassword(null);
+		});
 		// Apply stylesheets
 		var styleTiddlers = $tw.wiki.getTiddlersWithTag("$:/core/styles");
 		$tw.utils.each(styleTiddlers,function(title) {

core/modules/widgets/encrypt.js

@@ -0,0 +1,51 @@
+/*\
+title: $:/core/modules/widget/encrypt.js
+type: application/javascript
+module-type: widget
+
+Implements the encrypt widget.
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+var EncryptWidget = function(renderer) {
+	// Save state
+	this.renderer = renderer;
+	// Generate child nodes
+	this.generate();
+};
+
+EncryptWidget.prototype.generate = function() {
+	// Get the parameters from the attributes
+	this.filter = this.renderer.getAttribute("filter");
+	// Check whether we've got an encryption password
+	var isEncrypted = $tw.crypto.hasPassword();
+	// Encrypt the filtered tiddlers
+	var tiddlers = this.renderer.renderTree.wiki.filterTiddlers(this.filter),
+		json = {},
+		self = this;
+	$tw.utils.each(tiddlers,function(title) {
+		var tiddler = self.renderer.renderTree.wiki.getTiddler(title),
+			jsonTiddler = {};
+		for(var f in tiddler.fields) {
+			jsonTiddler[f] = tiddler.getFieldString(f);
+		}
+		json[title] = jsonTiddler;
+	});
+	var encryptedText = $tw.utils.htmlEncode($tw.crypto.encrypt(JSON.stringify(json)));
+	// Set the return element
+	this.tag = "pre";
+	this.attributes ={"class": "tw-encrypt"};
+	this.children = this.renderer.renderTree.createRenderers(this.renderer.renderContext,[{
+		type: "text",
+		text: encryptedText
+	}]);
+};
+
+exports.encrypt = EncryptWidget;
+
+})();

core/templates/PageTemplate.tid

@@ -5,6 +5,7 @@ title: $:/templates/PageTemplate
 
 <!-- The page header -->
 <div class="pull-right">
+{{$:/snippets/encryptionstatus}}
 <$button message="tw-NewTiddler" class="btn btn-mini btn-success">New</$button>
 <$button message="tw-save-wiki" class="btn btn-mini btn-primary">Save</$button>
 </div>

core/templates/store.area.template.html.tid

@@ -0,0 +1,13 @@
+title: $:/core/templates/store.area.template.html
+
+<$reveal type="nomatch" state="$:/isEncrypted" text="yes">
+`<div id="storeArea" style="display:none;">`
+{{{ [!is[shadow]] ||$:/core/templates/html-div-tiddler}}}
+`</div>`
+</$reveal>
+<$reveal type="match" state="$:/isEncrypted" text="yes">
+`<!------------- Encrypted tiddlers --------->`
+`<pre id="encryptedStoreArea" type="text/plain" style="display:none;">`
+<$encrypt filter="[!is[shadow]]"/>
+`</pre>`
+</$reveal>

core/templates/tiddlywiki5.template.html.tid

@@ -34,9 +34,7 @@ title: $:/core/templates/tiddlywiki5.template.html
 {{{ [is[shadow]] -[type[text/css]] -[type[application/javascript]has[module-type]] -[type[application/javascript]library[yes]] -[[$:/core/boot.js]] -[[$:/core/bootprefix.js]] ||$:/core/templates/html-div-tiddler}}}
 </div>
 <!----------- Ordinary tiddlers ----------->
-<div id="storeArea" style="display:none;">
-{{{ [!is[shadow]] ||$:/core/templates/html-div-tiddler}}}
-</div>
+{{$:/core/templates/store.area.template.html}}
 <!----------- Library modules ----------->
 <div id="libraryModules" style="display:none;">
 {{$:/core/lib/jquery.min.js||$:/core/templates/javascript-tiddler}}

core/wiki/encryptionstatus.tid

@@ -0,0 +1,11 @@
+title: $:/snippets/encryptionstatus
+
+<$reveal type="match" state="$:/isEncrypted" text="yes">
+This wiki is encrypted.
+<$button message="tw-clear-password">Clear password</$button>
+<$button message="tw-set-password">Change password</$button>
+</$reveal>
+<$reveal type="nomatch" state="$:/isEncrypted" text="yes">
+This wiki is not encrypted.
+<$button message="tw-set-password">Set password</$button>
+</$reveal>

editions/tw5.com/tiddlers/Internals.tid

@@ -28,6 +28,7 @@ Internally, TiddlyWiki is built on a number of key objects and mechanisms:
 * SyncMechanism
 * CommandMechanism
 * ConfigMechanism
+* EncryptionMechanism
 
 ! Plugin Module Types
 

editions/tw5.com/tiddlers/mechanisms/EncryptionMechanism.tid

@@ -0,0 +1,14 @@
+title: EncryptionMechanism
+tags: docs mechanism
+
+TiddlyWiki5 allows the entire content of a TiddlyWiki HTML file to be encrypted with the Stanford JavaScript Crypto Library. Opening an encrypted TiddlyWiki in the browser prompts for a password before decrypting and displaying the content.
+
+The EncryptionMechanism is implemented with the following elements:
+
+* A crypto "password vault" within the BootMechanism that holds the current encryption password
+* The ability of the BootMechanism to read a block of encrypted tiddlers from the TiddlyWiki file, to prompt the user for a password, and to decrypt the tiddlers
+* Handlers for the messages SetPasswordMessage and ClearPasswordMessage that handle the user interface for password changes
+* The `<$encrypt>` widget within the main file template that encrypts a filtered list of tiddlers with the currently held password
+* The [[$:/isEncrypted]] tiddler that contains "yes" or "no" according to whether there is a password in the password vault
+** The availability of this tiddler allows the RevealWidget to be used to selectively display user interface elements according to whether encryption is in force
+* The [[$:/snippets/encryptionstatus]] snippet that displays the current encryption status