<!--{{{-->
<link rel='alternate' type='application/rss+xml' title='RSS' href='index.xml' />
<!--}}}-->
Background: #fff
Foreground: #000
PrimaryPale: #8cf
PrimaryLight: #18f
PrimaryMid: #04b
PrimaryDark: #014
SecondaryPale: #ffc
SecondaryLight: #fe8
SecondaryMid: #db4
SecondaryDark: #841
TertiaryPale: #eee
TertiaryLight: #ccc
TertiaryMid: #999
TertiaryDark: #666
Error: #f88
/*{{{*/
body {background:[[ColorPalette::Background]]; color:[[ColorPalette::Foreground]];}

a {color:[[ColorPalette::PrimaryMid]];}
a:hover {background-color:[[ColorPalette::PrimaryMid]]; color:[[ColorPalette::Background]];}
a img {border:0;}

h1,h2,h3,h4,h5,h6 {color:[[ColorPalette::SecondaryDark]]; background:transparent;}
h1 {border-bottom:2px solid [[ColorPalette::TertiaryLight]];}
h2,h3 {border-bottom:1px solid [[ColorPalette::TertiaryLight]];}

.button {color:[[ColorPalette::PrimaryDark]]; border:1px solid [[ColorPalette::Background]];}
.button:hover {color:[[ColorPalette::PrimaryDark]]; background:[[ColorPalette::SecondaryLight]]; border-color:[[ColorPalette::SecondaryMid]];}
.button:active {color:[[ColorPalette::Background]]; background:[[ColorPalette::SecondaryMid]]; border:1px solid [[ColorPalette::SecondaryDark]];}

.header {background:[[ColorPalette::PrimaryMid]];}
.headerShadow {color:[[ColorPalette::Foreground]];}
.headerShadow a {font-weight:normal; color:[[ColorPalette::Foreground]];}
.headerForeground {color:[[ColorPalette::Background]];}
.headerForeground a {font-weight:normal; color:[[ColorPalette::PrimaryPale]];}

.tabSelected{color:[[ColorPalette::PrimaryDark]];
	background:[[ColorPalette::TertiaryPale]];
	border-left:1px solid [[ColorPalette::TertiaryLight]];
	border-top:1px solid [[ColorPalette::TertiaryLight]];
	border-right:1px solid [[ColorPalette::TertiaryLight]];
}
.tabUnselected {color:[[ColorPalette::Background]]; background:[[ColorPalette::TertiaryMid]];}
.tabContents {color:[[ColorPalette::PrimaryDark]]; background:[[ColorPalette::TertiaryPale]]; border:1px solid [[ColorPalette::TertiaryLight]];}
.tabContents .button {border:0;}

#sidebar {}
#sidebarOptions input {border:1px solid [[ColorPalette::PrimaryMid]];}
#sidebarOptions .sliderPanel {background:[[ColorPalette::PrimaryPale]];}
#sidebarOptions .sliderPanel a {border:none;color:[[ColorPalette::PrimaryMid]];}
#sidebarOptions .sliderPanel a:hover {color:[[ColorPalette::Background]]; background:[[ColorPalette::PrimaryMid]];}
#sidebarOptions .sliderPanel a:active {color:[[ColorPalette::PrimaryMid]]; background:[[ColorPalette::Background]];}

.wizard {background:[[ColorPalette::PrimaryPale]]; border:1px solid [[ColorPalette::PrimaryMid]];}
.wizard h1 {color:[[ColorPalette::PrimaryDark]]; border:none;}
.wizard h2 {color:[[ColorPalette::Foreground]]; border:none;}
.wizardStep {background:[[ColorPalette::Background]]; color:[[ColorPalette::Foreground]];
	border:1px solid [[ColorPalette::PrimaryMid]];}
.wizardStep.wizardStepDone {background:[[ColorPalette::TertiaryLight]];}
.wizardFooter {background:[[ColorPalette::PrimaryPale]];}
.wizardFooter .status {background:[[ColorPalette::PrimaryDark]]; color:[[ColorPalette::Background]];}
.wizard .button {color:[[ColorPalette::Foreground]]; background:[[ColorPalette::SecondaryLight]]; border: 1px solid;
	border-color:[[ColorPalette::SecondaryPale]] [[ColorPalette::SecondaryDark]] [[ColorPalette::SecondaryDark]] [[ColorPalette::SecondaryPale]];}
.wizard .button:hover {color:[[ColorPalette::Foreground]]; background:[[ColorPalette::Background]];}
.wizard .button:active {color:[[ColorPalette::Background]]; background:[[ColorPalette::Foreground]]; border: 1px solid;
	border-color:[[ColorPalette::PrimaryDark]] [[ColorPalette::PrimaryPale]] [[ColorPalette::PrimaryPale]] [[ColorPalette::PrimaryDark]];}
	
.wizard .notChanged {background:transparent;}
.wizard .changedLocally {background:#80ff80;}
.wizard .changedServer {background:#8080ff;}
.wizard .changedBoth {background:#ff8080;}
.wizard .notFound {background:#ffff80;}
.wizard .putToServer {background:#ff80ff;}
.wizard .gotFromServer {background:#80ffff;}

#messageArea {border:1px solid [[ColorPalette::SecondaryMid]]; background:[[ColorPalette::SecondaryLight]]; color:[[ColorPalette::Foreground]];}
#messageArea .button {color:[[ColorPalette::PrimaryMid]]; background:[[ColorPalette::SecondaryPale]]; border:none;}

.popupTiddler {background:[[ColorPalette::TertiaryPale]]; border:2px solid [[ColorPalette::TertiaryMid]];}

.popup {background:[[ColorPalette::TertiaryPale]]; color:[[ColorPalette::TertiaryDark]]; border-left:1px solid [[ColorPalette::TertiaryMid]]; border-top:1px solid [[ColorPalette::TertiaryMid]]; border-right:2px solid [[ColorPalette::TertiaryDark]]; border-bottom:2px solid [[ColorPalette::TertiaryDark]];}
.popup hr {color:[[ColorPalette::PrimaryDark]]; background:[[ColorPalette::PrimaryDark]]; border-bottom:1px;}
.popup li.disabled {color:[[ColorPalette::TertiaryMid]];}
.popup li a, .popup li a:visited {color:[[ColorPalette::Foreground]]; border: none;}
.popup li a:hover {background:[[ColorPalette::SecondaryLight]]; color:[[ColorPalette::Foreground]]; border: none;}
.popup li a:active {background:[[ColorPalette::SecondaryPale]]; color:[[ColorPalette::Foreground]]; border: none;}
.popupHighlight {background:[[ColorPalette::Background]]; color:[[ColorPalette::Foreground]];}
.listBreak div {border-bottom:1px solid [[ColorPalette::TertiaryDark]];}

.tiddler .defaultCommand {font-weight:bold;}

.shadow .title {color:[[ColorPalette::TertiaryDark]];}

.title {color:[[ColorPalette::SecondaryDark]];}
.subtitle {color:[[ColorPalette::TertiaryDark]];}

.toolbar {color:[[ColorPalette::PrimaryMid]];}
.toolbar a {color:[[ColorPalette::TertiaryLight]];}
.selected .toolbar a {color:[[ColorPalette::TertiaryMid]];}
.selected .toolbar a:hover {color:[[ColorPalette::Foreground]];}

.tagging, .tagged {border:1px solid [[ColorPalette::TertiaryPale]]; background-color:[[ColorPalette::TertiaryPale]];}
.selected .tagging, .selected .tagged {background-color:[[ColorPalette::TertiaryLight]]; border:1px solid [[ColorPalette::TertiaryMid]];}
.tagging .listTitle, .tagged .listTitle {color:[[ColorPalette::PrimaryDark]];}
.tagging .button, .tagged .button {border:none;}

.footer {color:[[ColorPalette::TertiaryLight]];}
.selected .footer {color:[[ColorPalette::TertiaryMid]];}

.sparkline {background:[[ColorPalette::PrimaryPale]]; border:0;}
.sparktick {background:[[ColorPalette::PrimaryDark]];}

.error, .errorButton {color:[[ColorPalette::Foreground]]; background:[[ColorPalette::Error]];}
.warning {color:[[ColorPalette::Foreground]]; background:[[ColorPalette::SecondaryPale]];}
.lowlight {background:[[ColorPalette::TertiaryLight]];}

.zoomer {background:none; color:[[ColorPalette::TertiaryMid]]; border:3px solid [[ColorPalette::TertiaryMid]];}

.imageLink, #displayArea .imageLink {background:transparent;}

.annotation {background:[[ColorPalette::SecondaryLight]]; color:[[ColorPalette::Foreground]]; border:2px solid [[ColorPalette::SecondaryMid]];}

.viewer .listTitle {list-style-type:none; margin-left:-2em;}
.viewer .button {border:1px solid [[ColorPalette::SecondaryMid]];}
.viewer blockquote {border-left:3px solid [[ColorPalette::TertiaryDark]];}

.viewer table, table.twtable {border:2px solid [[ColorPalette::TertiaryDark]];}
.viewer th, .viewer thead td, .twtable th, .twtable thead td {background:[[ColorPalette::SecondaryMid]]; border:1px solid [[ColorPalette::TertiaryDark]]; color:[[ColorPalette::Background]];}
.viewer td, .viewer tr, .twtable td, .twtable tr {border:1px solid [[ColorPalette::TertiaryDark]];}

.viewer pre {border:1px solid [[ColorPalette::SecondaryLight]]; background:[[ColorPalette::SecondaryPale]];}
.viewer code {color:[[ColorPalette::SecondaryDark]];}
.viewer hr {border:0; border-top:dashed 1px [[ColorPalette::TertiaryDark]]; color:[[ColorPalette::TertiaryDark]];}

.highlight, .marked {background:[[ColorPalette::SecondaryLight]];}

.editor input {border:1px solid [[ColorPalette::PrimaryMid]];}
.editor textarea {border:1px solid [[ColorPalette::PrimaryMid]]; width:100%;}
.editorFooter {color:[[ColorPalette::TertiaryMid]];}

#backstageArea {background:[[ColorPalette::Foreground]]; color:[[ColorPalette::TertiaryMid]];}
#backstageArea a {background:[[ColorPalette::Foreground]]; color:[[ColorPalette::Background]]; border:none;}
#backstageArea a:hover {background:[[ColorPalette::SecondaryLight]]; color:[[ColorPalette::Foreground]]; }
#backstageArea a.backstageSelTab {background:[[ColorPalette::Background]]; color:[[ColorPalette::Foreground]];}
#backstageButton a {background:none; color:[[ColorPalette::Background]]; border:none;}
#backstageButton a:hover {background:[[ColorPalette::Foreground]]; color:[[ColorPalette::Background]]; border:none;}
#backstagePanel {background:[[ColorPalette::Background]]; border-color: [[ColorPalette::Background]] [[ColorPalette::TertiaryDark]] [[ColorPalette::TertiaryDark]] [[ColorPalette::TertiaryDark]];}
.backstagePanelFooter .button {border:none; color:[[ColorPalette::Background]];}
.backstagePanelFooter .button:hover {color:[[ColorPalette::Foreground]];}
#backstageCloak {background:[[ColorPalette::Foreground]]; opacity:0.6; filter:'alpha(opacity:60)';}
/*}}}*/
/*{{{*/
* html .tiddler {height:1%;}

body {font-size:.75em; font-family:arial,helvetica; margin:0; padding:0;}

h1,h2,h3,h4,h5,h6 {font-weight:bold; text-decoration:none;}
h1,h2,h3 {padding-bottom:1px; margin-top:1.2em;margin-bottom:0.3em;}
h4,h5,h6 {margin-top:1em;}
h1 {font-size:1.35em;}
h2 {font-size:1.25em;}
h3 {font-size:1.1em;}
h4 {font-size:1em;}
h5 {font-size:.9em;}

hr {height:1px;}

a {text-decoration:none;}

dt {font-weight:bold;}

ol {list-style-type:decimal;}
ol ol {list-style-type:lower-alpha;}
ol ol ol {list-style-type:lower-roman;}
ol ol ol ol {list-style-type:decimal;}
ol ol ol ol ol {list-style-type:lower-alpha;}
ol ol ol ol ol ol {list-style-type:lower-roman;}
ol ol ol ol ol ol ol {list-style-type:decimal;}

.txtOptionInput {width:11em;}

#contentWrapper .chkOptionInput {border:0;}

.externalLink {text-decoration:underline;}

.indent {margin-left:3em;}
.outdent {margin-left:3em; text-indent:-3em;}
code.escaped {white-space:nowrap;}

.tiddlyLinkExisting {font-weight:bold;}
.tiddlyLinkNonExisting {font-style:italic;}

/* the 'a' is required for IE, otherwise it renders the whole tiddler in bold */
a.tiddlyLinkNonExisting.shadow {font-weight:bold;}

#mainMenu .tiddlyLinkExisting,
	#mainMenu .tiddlyLinkNonExisting,
	#sidebarTabs .tiddlyLinkNonExisting {font-weight:normal; font-style:normal;}
#sidebarTabs .tiddlyLinkExisting {font-weight:bold; font-style:normal;}

.header {position:relative;}
.header a:hover {background:transparent;}
.headerShadow {position:relative; padding:4.5em 0em 1em 1em; left:-1px; top:-1px;}
.headerForeground {position:absolute; padding:4.5em 0em 1em 1em; left:0px; top:0px;}

.siteTitle {font-size:3em;}
.siteSubtitle {font-size:1.2em;}

#mainMenu {position:absolute; left:0; width:10em; text-align:right; line-height:1.6em; padding:1.5em 0.5em 0.5em 0.5em; font-size:1.1em;}

#sidebar {position:absolute; right:3px; width:16em; font-size:.9em;}
#sidebarOptions {padding-top:0.3em;}
#sidebarOptions a {margin:0em 0.2em; padding:0.2em 0.3em; display:block;}
#sidebarOptions input {margin:0.4em 0.5em;}
#sidebarOptions .sliderPanel {margin-left:1em; padding:0.5em; font-size:.85em;}
#sidebarOptions .sliderPanel a {font-weight:bold; display:inline; padding:0;}
#sidebarOptions .sliderPanel input {margin:0 0 .3em 0;}
#sidebarTabs .tabContents {width:15em; overflow:hidden;}

.wizard {padding:0.1em 1em 0em 2em;}
.wizard h1 {font-size:2em; font-weight:bold; background:none; padding:0em 0em 0em 0em; margin:0.4em 0em 0.2em 0em;}
.wizard h2 {font-size:1.2em; font-weight:bold; background:none; padding:0em 0em 0em 0em; margin:0.4em 0em 0.2em 0em;}
.wizardStep {padding:1em 1em 1em 1em;}
.wizard .button {margin:0.5em 0em 0em 0em; font-size:1.2em;}
.wizardFooter {padding:0.8em 0.4em 0.8em 0em;}
.wizardFooter .status {padding:0em 0.4em 0em 0.4em; margin-left:1em;}
.wizard .button {padding:0.1em 0.2em 0.1em 0.2em;}

#messageArea {position:fixed; top:2em; right:0em; margin:0.5em; padding:0.5em; z-index:2000; _position:absolute;}
.messageToolbar {display:block; text-align:right; padding:0.2em 0.2em 0.2em 0.2em;}
#messageArea a {text-decoration:underline;}

.tiddlerPopupButton {padding:0.2em 0.2em 0.2em 0.2em;}
.popupTiddler {position: absolute; z-index:300; padding:1em 1em 1em 1em; margin:0;}

.popup {position:absolute; z-index:300; font-size:.9em; padding:0; list-style:none; margin:0;}
.popup .popupMessage {padding:0.4em;}
.popup hr {display:block; height:1px; width:auto; padding:0; margin:0.2em 0em;}
.popup li.disabled {padding:0.4em;}
.popup li a {display:block; padding:0.4em; font-weight:normal; cursor:pointer;}
.listBreak {font-size:1px; line-height:1px;}
.listBreak div {margin:2px 0;}

.tabset {padding:1em 0em 0em 0.5em;}
.tab {margin:0em 0em 0em 0.25em; padding:2px;}
.tabContents {padding:0.5em;}
.tabContents ul, .tabContents ol {margin:0; padding:0;}
.txtMainTab .tabContents li {list-style:none;}
.tabContents li.listLink { margin-left:.75em;}

#contentWrapper {display:block;}
#splashScreen {display:none;}

#displayArea {margin:1em 17em 0em 14em;}

.toolbar {text-align:right; font-size:.9em;}

.tiddler {padding:1em 1em 0em 1em;}

.missing .viewer,.missing .title {font-style:italic;}

.title {font-size:1.6em; font-weight:bold;}

.missing .subtitle {display:none;}
.subtitle {font-size:1.1em;}

.tiddler .button {padding:0.2em 0.4em;}

.tagging {margin:0.5em 0.5em 0.5em 0; float:left; display:none;}
.isTag .tagging {display:block;}
.tagged {margin:0.5em; float:right;}
.tagging, .tagged {font-size:0.9em; padding:0.25em;}
.tagging ul, .tagged ul {list-style:none; margin:0.25em; padding:0;}
.tagClear {clear:both;}

.footer {font-size:.9em;}
.footer li {display:inline;}

.annotation {padding:0.5em; margin:0.5em;}

* html .viewer pre {width:99%; padding:0 0 1em 0;}
.viewer {line-height:1.4em; padding-top:0.5em;}
.viewer .button {margin:0em 0.25em; padding:0em 0.25em;}
.viewer blockquote {line-height:1.5em; padding-left:0.8em;margin-left:2.5em;}
.viewer ul, .viewer ol {margin-left:0.5em; padding-left:1.5em;}

.viewer table, table.twtable {border-collapse:collapse; margin:0.8em 1.0em;}
.viewer th, .viewer td, .viewer tr,.viewer caption,.twtable th, .twtable td, .twtable tr,.twtable caption {padding:3px;}
table.listView {font-size:0.85em; margin:0.8em 1.0em;}
table.listView th, table.listView td, table.listView tr {padding:0px 3px 0px 3px;}

.viewer pre {padding:0.5em; margin-left:0.5em; font-size:1.2em; line-height:1.4em; overflow:auto;}
.viewer code {font-size:1.2em; line-height:1.4em;}

.editor {font-size:1.1em;}
.editor input, .editor textarea {display:block; width:100%; font:inherit;}
.editorFooter {padding:0.25em 0em; font-size:.9em;}
.editorFooter .button {padding-top:0px; padding-bottom:0px;}

.fieldsetFix {border:0; padding:0; margin:1px 0px 1px 0px;}

.sparkline {line-height:1em;}
.sparktick {outline:0;}

.zoomer {font-size:1.1em; position:absolute; overflow:hidden;}
.zoomer div {padding:1em;}

* html #backstage {width:99%;}
* html #backstageArea {width:99%;}
#backstageArea {display:none; position:relative; overflow: hidden; z-index:150; padding:0.3em 0.5em 0.3em 0.5em;}
#backstageToolbar {position:relative;}
#backstageArea a {font-weight:bold; margin-left:0.5em; padding:0.3em 0.5em 0.3em 0.5em;}
#backstageButton {display:none; position:absolute; z-index:175; top:0em; right:0em;}
#backstageButton a {padding:0.1em 0.4em 0.1em 0.4em; margin:0.1em 0.1em 0.1em 0.1em;}
#backstage {position:relative; width:100%; z-index:50;}
#backstagePanel {display:none; z-index:100; position:absolute; width:90%; margin:0em 3em 0em 3em; padding:1em 1em 1em 1em;}
.backstagePanelFooter {padding-top:0.2em; float:right;}
.backstagePanelFooter a {padding:0.2em 0.4em 0.2em 0.4em;}
#backstageCloak {display:none; z-index:20; position:absolute; width:100%; height:100px;}

.whenBackstage {display:none;}
.backstageVisible .whenBackstage {display:block;}
/*}}}*/
/***
StyleSheet for use when a translation requires any css style changes.
This StyleSheet can be used directly by languages such as Chinese, Japanese and Korean which need larger font sizes.
***/
/*{{{*/
body {font-size:0.8em;}
#sidebarOptions {font-size:1.05em;}
#sidebarOptions a {font-style:normal;}
#sidebarOptions .sliderPanel {font-size:0.95em;}
.subtitle {font-size:0.8em;}
.viewer table.listView {font-size:0.95em;}
/*}}}*/
/*{{{*/
@media print {
#mainMenu, #sidebar, #messageArea, .toolbar, #backstageButton, #backstageArea {display: none ! important;}
#displayArea {margin: 1em 1em 0em 1em;}
/* Fixes a feature in Firefox 1.5.0.2 where print preview displays the noscript content */
noscript {display:none;}
}
/*}}}*/
<!--{{{-->
<div class='header' macro='gradient vert [[ColorPalette::PrimaryLight]] [[ColorPalette::PrimaryMid]]'>
<div class='headerShadow'>
<span class='siteTitle' refresh='content' tiddler='SiteTitle'></span>&nbsp;
<span class='siteSubtitle' refresh='content' tiddler='SiteSubtitle'></span>
</div>
<div class='headerForeground'>
<span class='siteTitle' refresh='content' tiddler='SiteTitle'></span>&nbsp;
<span class='siteSubtitle' refresh='content' tiddler='SiteSubtitle'></span>
</div>
</div>
<div id='mainMenu' refresh='content' tiddler='MainMenu'></div>
<div id='sidebar'>
<div id='sidebarOptions' refresh='content' tiddler='SideBarOptions'></div>
<div id='sidebarTabs' refresh='content' force='true' tiddler='SideBarTabs'></div>
</div>
<div id='displayArea'>
<div id='messageArea'></div>
<div id='tiddlerDisplay'></div>
</div>
<!--}}}-->
<!--{{{-->
<div class='toolbar' macro='toolbar [[ToolbarCommands::ViewToolbar]]'></div>
<div class='title' macro='view title'></div>
<div class='subtitle'><span macro='view modifier link'></span>, <span macro='view modified date'></span> (<span macro='message views.wikified.createdPrompt'></span> <span macro='view created date'></span>)</div>
<div class='tagging' macro='tagging'></div>
<div class='tagged' macro='tags'></div>
<div class='viewer' macro='view text wikified'></div>
<div class='tagClear'></div>
<!--}}}-->
<!--{{{-->
<div class='toolbar' macro='toolbar [[ToolbarCommands::EditToolbar]]'></div>
<div class='title' macro='view title'></div>
<div class='editor' macro='edit title'></div>
<div macro='annotations'></div>
<div class='editor' macro='edit text'></div>
<div class='editor' macro='edit tags'></div><div class='editorFooter'><span macro='message views.editor.tagPrompt'></span><span macro='tagChooser'></span></div>
<!--}}}-->
To get started with this blank TiddlyWiki, you'll need to modify the following tiddlers:
* SiteTitle & SiteSubtitle: The title and subtitle of the site, as shown above (after saving, they will also appear in the browser title bar)
* MainMenu: The menu (usually on the left)
* DefaultTiddlers: Contains the names of the tiddlers that you want to appear when the TiddlyWiki is opened
You'll also need to enter your username for signing your edits: <<option txtUserName>>
These InterfaceOptions for customising TiddlyWiki are saved in your browser

Your username for signing your edits. Write it as a WikiWord (eg JoeBloggs)

<<option txtUserName>>
<<option chkSaveBackups>> SaveBackups
<<option chkAutoSave>> AutoSave
<<option chkRegExpSearch>> RegExpSearch
<<option chkCaseSensitiveSearch>> CaseSensitiveSearch
<<option chkAnimate>> EnableAnimations

----
Also see AdvancedOptions
<<importTiddlers>>
This TiddlyWiki contains the current version of the TiddlerEncryptionPlugin.

The TiddlerEncryptionPlugin will encrypt a tiddler, using a password you supply, if you tag it with Encrypt(''promptString'').

The ''promptString'' is simply some text to help remind you of what the password is.

There is also a copy of the previous major release TiddlerEncryptionPlugin_Previous.

The difference between the two is the newer one obscures passwords on entry whilst the older one uses the javascript ''prompt()'' function to enter the passwords, allowing people to see what you type (this also allows you to visually confirm what you type, if you mistype or forget the password, your data is lost).

Both versions store the data in the same way, so you may use either version, which ever suits your taste. Do not try to have both versions active at one time - your TiddlyWiki will fail to open if you do so.

{{{:-)}}}

...Lyall



Sourced from Remotely-Helpful.com
TiddlerEncryptionPlugin
/***
|Name|TiddlerEncryptionPlugin|
|Author|Lyall Pearce|
|Source|http://www.Remotely-Helpful.com/TiddlyWiki/TiddlerEncryptionPlugin.html|
|License|[[Creative Commons Attribution-Share Alike 3.0 License|http://creativecommons.org/licenses/by-sa/3.0/]]|
|Version|3.2.2|
|~CoreVersion|2.4.0|
|Requires|None|
|Overrides|store.getSaver().externalizeTiddler(), store.getTiddler() and store.getTiddlerText()|
|Description|Encrypt/Decrypt Tiddlers with a Password key|

!!!!!Usage
<<<
* Tag a tiddler with Encrypt(prompt)
** Consider the 'prompt' something to help you remember the password with. If multiple tiddlers can be encrypted with the same 'prompt' and you will only be asked for the password once.
* Upon save, the Tiddler will be encrypted and the tag replaced with Decrypt(prompt).
** Failure to encrypt (by not entering a password) will leave the tiddler unencrypted and will leave the Encrypt(prompt) tag in place. This means that the next time you save, you will be asked for the password again.
** To have multiple tiddlers use the same password - simply use the same 'prompt'.
** Tiddlers that are encrypted may be automatically tagged 'excludeSearch' as there is no point in searching encrypted data - this is configurable by an option - you still may want to search the titles of encrypted tiddlers
** Tiddlers that are encrypted may be automatically tagged 'excludeLists', if you have them encrypted, you may also want to keep them 'hidden' - this is configurable by an option.
** Automatic removal of excludeLists and excludeSearch tags is performed, if the above two options are set, only if these two tags are the last 2 tags for a tiddler, if they are positioned somewhere else in the tags list, they will be left in place, meaning that the decrypted tiddler will not be searchable and/or will not appear in lists.
** Encrypted tiddlers are stored as displayable hex, to keep things visibly tidy, should you display an encrypted tiddler. There is nothing worse than seeing a pile of gobbledy gook on your screen. Additionally, the encrypted data is easily cut/paste/emailed if displayed in hex form.
* Tiddlers are decrypted only if you click the decrypt button or the decryptAll button, not when you load the TiddlyWiki
** If you don't display a tiddler, you won't have the option to decrypt it (unless you use the {{{<<EncryptionDecryptAll>>}}} macro)
** Tiddlers will re-encrypt automatically on save.
** Decryption of Tiddlers does not make your TiddlyWiki 'dirty' - you will not be asked to save if you leave the page.
* Errors are reported via diagnostic messages.
** Empty passwords, on save, will result in the tiddler being saved unencrypted - this should only occur with new tiddlers, decrypted tiddlers or with tiddlers who have had their 'prompt' tag changed.
** Encrypted tiddlers know if they are decrypted successfully - failure to decrypt a tiddler will ''not'' lose your data.
** Editing of an encrypted (that has not been unencrypted) tiddler will result in loss of that tiddler as the SHA1 checksums will no longer match, upon decryption. To this end, it is best that you do not check the option. You can, however edit an encrypted tiddler tag list - just do ''not'' change the tiddler contents.
** To change the password on a Tiddler, change the Encrypt('prompt') tag to a new prompt value, after decrypting the tiddler.
** You can edit the tags of an encrypted tiddler, so long as you do not edit the text.
** To change the password for all tiddlers of a particular prompt, use the {{{<<EncryptionChangePassword ["button text" ["tooltip text" ["prompt string" ["accessKey"]]]]>>}}} macro.
** To decrypt all tiddlers of a particular "prompt string", use the {{{<<EncryptionDecryptAll ["button text" ["tooltip text" ["prompt string" ["accessKey"]]]]>>}}} macro - this will make tiddlers encrypted with "prompt string" searchable - or prompt for all 'prompt strings', if none is supplied.
<<<
!!!!!Configuration
<<<
Useful Buttons: 
<<EncryptionChangePassword>> - Change passwords of encrypted tiddlers.
<<EncryptionDecryptAll>> - Decrypt ALL tiddlers - enables searching contents of encrypted tiddlers.
<<option chkExcludeEncryptedFromSearch>> - If set, Encrypted Tiddlers are excluded from searching by tagging with excludeSearch. If Clear, excludeSearch is not added and it is also removed from existing Encrypted Tiddlers only if it is the last Tag. Searching of Encrypted Tiddlers is only meaningful for the Title and Tags.
<<option chkExcludeEncryptedFromLists>> - If set, Encrypted Tiddlers are excluded from lists by tagging with excludeLists. If Clear, excludeLists is not added and it is also removed from existing Encrypted Tiddlers only if it is the last Tag. Preventing encrypted tiddlers from appearing in lists effectively hides them.
<<option chkShowDecryptButtonInContent>> - If set, Encrypted Tiddlers content is replaced by <<EncryptionDecryptThis>> button. This has consequences, in the current version as, if you edit the tiddler without decrypting it, you lose the contents.
<<<
!!!!!Revision History
<<<
* 3.2.2 - added tiddler.changed() calls whenever plugin changes tiddler content as per recommendations by Udo.
* 3.2.1 - Returned the <<EncryptionDecryptThis>> button as an option.
* 3.2.0 - Ditched the 'Decrypt' button showing up in the tiddler contents if the tiddler is encrypted. It caused too much pain if you edit the tiddler without decrypting it - you lost your data as it was replaced by a Decrypt Macro call!  Additionally, a 'decrypt' button will now appear in the toolbar, just before the edit button, if the tiddler is encrypted. This button only appears if using core TiddlyWiki version 2.4 or above.
* 3.1.1 - Obscure bug whereby if an encrypted tiddler was a certain length, it would refuse to decrypt.
* 3.1.0 - When creating a new Encrypt(prompt) tiddler and you have not previously decrypted a tiddler with the same prompt, on save, you will be prompted for the password to encrypt the tiddler. Prior to encrypting, an attempt to decrypt all other tiddlers with the same prompt, is performed. If any tiddler fails to decrypt, the save is aborted - this is so you don't accidentally have 2 (or more!) passwords for the same prompt. Either you enter the correct password, change the prompt string and try re-saving or you cancel (and the tiddler is saved unencrypted).
* 3.0.1 - Allow Enter to be used for password entry, rather than having to press the OK button.
* 3.0.0 - Major revamp internally to support entry of passwords using forms such that passwords are no longer visible on entry. Completely backward compatible with old encrypted tiddlers. No more using the javascript prompt() function.
<<<
!!!!!Additional work

***/
//{{{
version.extensions.TiddlerEncryptionPlugin = {major: 3, minor: 2, revision: 2, date: new Date(2012,05,17)};

// where I cache the passwords - for want of a better place.
config.encryptionPasswords = new Array();
config.encryptionReEnterPasswords = false;

if(config.options.chkExcludeEncryptedFromSearch == undefined) config.options.chkExcludeEncryptedFromSearch = false;
if(config.options.chkExcludeEncryptedFromLists == undefined) config.options.chkExcludeEncryptedFromLists = false;
if(config.options.chkShowDecryptButtonInContent == undefined) config.options.chkShowDecryptButtonInContent = false;

config.macros.EncryptionChangePassword = {};
config.macros.EncryptionChangePassword.handler = function(place,macroName,params,wikifier,paramString,tiddler) {
    var theButton = createTiddlyButton(place,
				       (params[0] && params[0].length > 0) ? params[0] : "Change Passwords", 
				       (params[1] && params[1].length > 0) ? params[1] : "Change Passwords" + (params[2] ? " for prompt "+params[2] : ""), 
				       onClickEncryptionChangePassword,
				       null,
				       null,
				       params[3]);
    if(params[2] && params[2].length > 0) {
	theButton.setAttribute("promptString", params[2]);
    }
};

config.macros.EncryptionDecryptAll = {};
config.macros.EncryptionDecryptAll.handler = function(place,macroName,params,wikifier,paramString,tiddler) {
    var theButton = createTiddlyButton(place,
				       (params[0] && params[0].length > 0) ? params[0] : "Decrypt All", 
				       (params[1] && params[1].length > 0) ? params[1] : "Decrypt All Tiddlers" + ((params[2] && params[2].length > 0) ? " for prompt "+params[2] : " for a given 'prompt string'"), 
				       onClickEncryptionDecryptAll,
				       null,
				       null,
				       params[3]);
    if(params[2] && params[2].length > 0) {
	theButton.setAttribute("promptString", params[2]);
    }
};

config.macros.EncryptionDecryptThis = {};
config.macros.EncryptionDecryptThis.handler = function(place,macroName,params,wikifier,paramString,tiddler) {
    var theButton = createTiddlyButton(place,
				       (params[0] && params[0].length > 0) ? params[0] : "Decrypt", 
				       (params[1] && params[1].length > 0) ? params[1] : "Decrypt this Tiddler", 
				       onClickEncryptionDecryptThis,
				       null,
				       null,
				       params[3]);
    if(params[2] && params[2].length > 0) {
	theButton.setAttribute("theTiddler", params[2]);
    }
};
// toolbar button to decrypt tiddlers.
config.commands.decryptThis = {
  text: "decrypt",
  tooltip: "Decrypt this tiddler",
  isEnabled : function(tiddler) {
	// Only show decrypt button if tiddler is tagged as Decrypt(
	if(tiddler.tags.join().indexOf('Decrypt(') == -1)  {
	    return false;
	} else {
	    return true;
	}
    },	
  handler: function(event, src, title) {
	encryptionGetAndDecryptTiddler(title);
	return false; 
    }
};
// core version 2.4 or above get a 'decrypt' button in the toolbar.
if(config.shadowTiddlers && config.shadowTiddlers.ToolbarCommands  && config.shadowTiddlers.ToolbarCommands.indexOf('decryptThis') == -1) {
    // put our toolbar button in before the edit button.
    // won't work if editTiddler is not the default item (prefixed with plus)
    config.shadowTiddlers.ToolbarCommands.replace(/\+editTiddler/,'decryptThis +editTiddler');
}


// Called by the EncryptionChangePassword macro/button
// Also invoked by the callback for password entry
function onClickEncryptionChangePassword(eventObject) {
    var promptString;
    if(!promptString && this.getAttribute) {
	promptString = this.getAttribute("promptString");
    }
    // I do call this function directly
    if(!promptString && typeof(eventObject) == "string") {
	promptString = eventObject;
    }
    if(!promptString) {
	promptString = prompt("Enter 'prompt string' to change password for:","");
    }
    if(!promptString) {
	return;
    }
    if(! config.encryptionPasswords[promptString]) {
	var changePasswordContext = {changePasswordPromptString: promptString,
				     callbackFunction: MyChangePasswordPromptCallback_TiddlerEncryptionPlugin};
	MyPrompt_TiddlerEncryptionPlugin(promptString,"",changePasswordContext);
	return;
	// Callback function will re-invoke this function
    }

    // Decrypt ALL tiddlers for that prompt
    onClickEncryptionDecryptAll(promptString);
    // Now ditch the cached password, this will force the re-request for the new password, on save.
    displayMessage("Save TiddlyWiki to set new password for '"+promptString+"'");
    config.encryptionPasswords[promptString] = null;
    // mark store as dirty so a save will be requrested.
    store.setDirty(true);
    autoSaveChanges(); 
    return;
};
// Called by the password entry form when the user clicks 'OK' button.
function MyChangePasswordPromptCallback_TiddlerEncryptionPlugin(context) {
    config.encryptionPasswords[context.passwordPrompt] = context.password;
    onClickEncryptionChangePassword(context.changePasswordPromptString);
    return;
}
// Called by the EncryptionDecryptThis macro/button
function onClickEncryptionDecryptThis() {
    var theTiddler = this.getAttribute("theTiddler");
    if(!theTiddler) {
	return;
    }
    encryptionGetAndDecryptTiddler(theTiddler);
    return;
};

function encryptionGetAndDecryptTiddler(title) {
    config.encryptionReEnterPasswords = true;
    try {
	theTiddler = store.getTiddler(title);
	config.encryptionReEnterPasswords = false;
	story.refreshAllTiddlers();
    } catch (e) {
	if(e == "DecryptionFailed") {
	    displayMessage("Decryption failed");
	    return;
	}
    } // catch
    return;
};

// called by the EncryptionDecryptAlll macro/button
// Also called by the callback after the user clicks 'OK' button on the password entry form
function onClickEncryptionDecryptAll(eventObject) {
    var promptString;
    if(!promptString && this.getAttribute) {
	promptString = this.getAttribute("promptString");
    }
    // I do call this function directly
    if(!promptString && typeof(eventObject) == "string") {
	promptString = eventObject;
    }
    if(!promptString) {
	promptString = "";
    }

    // Loop through all tiddlers, looking to see if there are any Decrypt(promptString) tagged tiddlers
    // If there are, check to see if their password has been cached.
    // If not, ask for the first one that is missing, that we find
    // the call back function will store that password then invoke this function again, 
    // which will repeat the whole process. If we find all passwords have been cached
    // then we will finally do the decryptAll functionality, which will then
    // be able to decrypt all the required tiddlers, without prompting.
    // We have to do this whole rigmarole because we are using a 'form' to enter the password
    // rather than the 'prompt()' function - which shows the value of the password.
    var tagToSearchFor="Decrypt("+promptString;
    config.encryptionReEnterPasswords = true; 
    var promptGenerated = false;
    store.forEachTiddler(function(store,tiddler) {
	    // Note, there is no way to stop the forEachTiddler iterations
	    if(!promptGenerated && tiddler && tiddler.tags) {
		for(var ix=0; ix<tiddler.tags.length && !promptGenerated; ix++) {
		    if(tiddler.tags[ix].indexOf(tagToSearchFor) == 0) {
			var tag = tiddler.tags[ix];
			var lastBracket=tag.lastIndexOf(")");
			if(lastBracket >= 0) {
			    // Ok, tagged with Encrypt(passwordPrompt)
			    // extract the passwordPrompt name
			    var passwordPromptString=tag.substring(8,lastBracket);
			    if(!config.encryptionPasswords[passwordPromptString]) {
				// no password cached, prompt and cache it, rather than decryptAll
				// callback from prompting form will resume decryptAll attempt.
				var decryptAllContext = {decryptAllPromptString: promptString,
							 callbackFunction: MyDecryptAllPromptCallback_TiddlerEncryptionPlugin};
				MyPrompt_TiddlerEncryptionPlugin(passwordPromptString,"",decryptAllContext);
				promptGenerated = true;
			    } // if(!config.encryptionPasswords
			} // if(lastBracket
		    } // if(tiddler.tags[ix]..
		} // for
	    } // if
	}); // store.forEachTiddler
    // If we get here, all passwords have been cached.
    if(!promptGenerated) {
	config.encryptionReEnterPasswords = false;
	// Now do the decrypt all functionality
	try {
	    store.forEachTiddler(function(store,tiddler) {
		    // Note, there is no way to stop the forEachTiddler iterations
		    if(tiddler && tiddler.tags) {
			for(var ix=0; ix<tiddler.tags.length; ix++) {
			    if(tiddler.tags[ix].indexOf(tagToSearchFor) == 0) {
				try {
				    CheckTiddlerForDecryption_TiddlerEncryptionPlugin(tiddler);
				} catch (e) {
				    displayMessage("Decryption of '"+tiddler.title+"' failed.");
				    // throw e;
				}
			    } // if(tiddler.tags
			} // for
		    } // if
		}); // store.forEachTiddler
	    displayMessage("All tiddlers" + (promptString != "" ? " for '"+promptString+"'" : "") + " have been decrypted");
	} catch (e) {
	    if(e == "DecryptionFailed") {
		return;
	    }
	} // catch
    }
    return;
};

function MyDecryptAllPromptCallback_TiddlerEncryptionPlugin(context) {
    config.encryptionPasswords[context.passwordPrompt] = context.password;
    // restart the decryptAll process again after the user has entered a password.
    onClickEncryptionDecryptAll(context.decryptAllPromptString);
    return;
}

saveChanges_TiddlerEncryptionPlugin = saveChanges;
saveChanges = function(onlyIfDirty,tiddlers) {
    // Loop through all tiddlers, looking to see if there are any Encrypt(string) tagged tiddlers
    // If there are, check to see if their password has been cached.
    // If not, ask for the first one that is missing, that we find
    // the call back function will store that password then invoke this function again, 
    // which will repeat the whole process. If we find all passwords have been cached
    // then we will finally call the original saveChanges() function, which will then
    // be able to save the tiddlers.
    // We have to do this whole rigmarole because we are using a 'form' to enter the password
    // rather than the 'prompt()' function - which shows the value of the password.
    config.encryptionReEnterPasswords = true; 
    var promptGenerated = false;
    store.forEachTiddler(function(store,tiddler) {
	    if(!promptGenerated && tiddler && tiddler.tags) {
		for(var ix=0; ix<tiddler.tags.length && !promptGenerated; ix++) {
		    if(tiddler.tags[ix].indexOf("Encrypt(") == 0) {
			var tag = tiddler.tags[ix];
			var lastBracket=tag.lastIndexOf(")");
			if(lastBracket >= 0) {
			    // Ok, tagged with Encrypt(passwordPrompt)
			    // extract the passwordPrompt name
			    var passwordPrompt=tag.substring(8,lastBracket);
			    if(!config.encryptionPasswords[passwordPrompt]) {
				// no password cached, prompt and cache it, rather than save
				var saveContext = {onlyIfDirty: onlyIfDirty, 
						   tiddlers: tiddlers, 
				                   callbackFunction: MySavePromptCallback_TiddlerEncryptionPlugin};
				MyPrompt_TiddlerEncryptionPlugin(passwordPrompt,"",saveContext);
				promptGenerated = true;
			    } // if(!config.encryptionPasswords
			} // if(lastBracket
		    } // if(tiddler.tags[ix]..
		} // for
	    } // if
	}); // store.forEachTiddler
    // If we get here, all passwords have been cached.
    if(!promptGenerated) {
	config.encryptionReEnterPasswords = false;
	saveChanges_TiddlerEncryptionPlugin(onlyIfDirty,tiddlers);
    }
    return;
}

function MySavePromptCallback_TiddlerEncryptionPlugin(context) {
    config.encryptionPasswords[context.passwordPrompt] = context.password;
    // validate the password entered by attempting to decrypt all tiddlers
    // with the same encryption prompt string.
    onClickEncryptionDecryptAll(context.passwordPrompt);

    // restart the save process again
    saveChanges(context.onlyIfDirty, context.tiddlers);
    return;
}

store.getSaver().externalizeTiddler_TiddlerEncryptionPlugin = store.getSaver().externalizeTiddler;
store.getSaver().externalizeTiddler = function(store, tiddler) {
    // Ok, got the tiddler, track down the passwordPrompt in the tags.
    // track down the Encrypt(passwordPrompt) tag
    if(tiddler && tiddler.tags) {
	for(var g=0; g<tiddler.tags.length; g++) {
	    var tag = tiddler.tags[g];
	    if(tag.indexOf("Encrypt(") == 0) {
		var lastBracket=tag.lastIndexOf(")");
		if(lastBracket >= 0) {
		    // Ok, tagged with Encrypt(passwordPrompt)
		    // extract the passwordPrompt name
		    var passwordPrompt=tag.substring(8,lastBracket);
		    // Ok, Encrypt this tiddler!
		    var decryptedSHA1 = Crypto.hexSha1Str(tiddler.text);
		    var password =  GetAndSetPasswordForPrompt_TiddlerEncryptionPlugin(passwordPrompt);
		    if(password) {
			var encryptedText = TEAencrypt(tiddler.text, password);
			encryptedText = StringToHext_TiddlerEncryptionPlugin(encryptedText);
			tiddler.text = "Encrypted("+decryptedSHA1+")\n"+encryptedText;
			// Replace the Tag with the Decrypt() tag
			tiddler.tags[g]="Decrypt("+passwordPrompt+")";
			// prevent searches on encrypted tiddlers, still nice to search on title though.
			if(config.options.chkExcludeEncryptedFromSearch == true) {
			    tiddler.tags.push("excludeSearch");
			}
			// prevent lists of encrypted tiddlers
			if(config.options.chkExcludeEncryptedFromLists == true) {
			    tiddler.tags.push("excludeLists");
			}
			tiddler.changed();
			// let the store know it's dirty
			store.setDirty(tiddler.title, true);
		    } else {
			// do not encrypt - no password entered
		    }
		    break;
		} // if (lastBracket...
	    } // if(tag.indexOf(...
	} // for(var g=0;...
    } // if(tiddler.tags...
    
    // Then, finally, do the save by calling the function we override.

    return store.getSaver().externalizeTiddler_TiddlerEncryptionPlugin(store, tiddler);
};

function CheckTiddlerForDecryption_TiddlerEncryptionPlugin(tiddler) {
    if(tiddler && tiddler.tags) {
	for(var g=0; g<tiddler.tags.length; g++) {
	    var tag = tiddler.tags[g];
	    if(tag.indexOf("Decrypt(") == 0) {
		var lastBracket=tag.lastIndexOf(")");
		if(lastBracket >= 0) {
		    if(tiddler.text.substr(0,10) == "Encrypted(") {
			var closingSHA1Bracket = tiddler.text.indexOf(")");
			var decryptedSHA1 = tiddler.text.substring(10, closingSHA1Bracket);
			// Ok, tagged with Decrypt(passwordPrompt)
			// extract the passwordPrompt name
			var passwordPrompt=tag.substring(8,lastBracket);
			// Ok, Decrypt this tiddler!
			var decryptedText = tiddler.text.substr(closingSHA1Bracket+2);
			decryptedText = HexToString_TiddlerEncryptionPlugin(decryptedText);
                        // prompt("Decryption request for Tiddler '"+tiddler.title+"'");
			var password = GetAndSetPasswordForPromptToDecrypt_TiddlerEncryptionPlugin(passwordPrompt);
			if(password) {
			    decryptedText = TEAdecrypt(decryptedText, password );
			    var thisDecryptedSHA1 = Crypto.hexSha1Str(decryptedText);
			    if(decryptedSHA1 == thisDecryptedSHA1) {
				tiddler.text = decryptedText;
				// Replace the Tag with the Encrypt() tag
				tiddler.tags[g]="Encrypt("+passwordPrompt+")";
				if(tiddler.tags[tiddler.tags.length-1] == 'excludeLists') {
				    // Remove exclude lists only if it's the last entry
				    // as it's automatically put there by encryption
				    tiddler.tags.length--;
				}
				if(tiddler.tags[tiddler.tags.length-1] == 'excludeSearch') {
				    // Remove exclude search only if it's the last entry
				    // as it's automatically put there by encryption
				    tiddler.tags.length--;
				}
				tiddler.changed();
			    } else {
				// Did not decrypt, discard the password from the cache
				config.encryptionPasswords[passwordPrompt] = null;
				config.encryptionReEnterPasswords = false;
				throw "DecryptionFailed";
			    }
			} else {
			    // no password supplied, dont bother trying to decrypt
			    config.encryptionReEnterPasswords = false;
			    throw "DecryptionFailed";
			}
		    } else {
			// Tagged as encrypted but not expected format, just leave it unchanged
		    }
		    break; // out of for loop
		} // if (lastBracket...
	    } // if(tag.indexOf(...
	} // for(var g=0;...
    } // if (tiddler && tags)
    return tiddler;
};

store.getTiddler_TiddlerEncryptionPlugin = store.getTiddler;
store.getTiddler = function(title) {
    var tiddler = store.getTiddler_TiddlerEncryptionPlugin(title);
    if(tiddler) { // shadow tiddlers are not expected to be encrypted.
	try {
	    return CheckTiddlerForDecryption_TiddlerEncryptionPlugin(tiddler);
	} catch (e) {
	    if (config.options.chkShowDecryptButtonInContent == true) {
		if(e == "DecryptionFailed") {
		    var tiddler = store.getTiddler("DecryptionFailed");
		    if(!tiddler) {
			tiddler = new Tiddler();
			tiddler.set(title,
				    "<<EncryptionDecryptThis \"Decrypt\" \"Decrypt this tiddler\" \""+title+"\">>",
				    config.views.wikified.shadowModifier,
				    version.date,[],version.date);
		    } 
		    return tiddler;
		} // if(e)
	    }
	    return(tiddler);
	} // catch
    } // if(tiddler) {
    return null;
};

store.getTiddlerText_TiddlerEncryptionPlugin = store.getTiddlerText;
store.getTiddlerText = function(title,defaultText) {
    // Simply retrieve the tiddler, normally, if it requires decryption, it will be decrypted
    var decryptedTiddler = store.getTiddler(title);
    if(decryptedTiddler) {
	return decryptedTiddler.text;
    }
    //Ok, rather than duplicate all the core code, the above code should fail if we reach here
    // let the core code take over.
    return  store.getTiddlerText_TiddlerEncryptionPlugin(title,defaultText);
};

// Given a prompt, search our cache to see if we have already entered the password.
// Can return null if the user enters nothing.
function MyPrompt_TiddlerEncryptionPlugin(promptString,defaultValue,context) {
    if(!context) {
	context = {};
    }
    context.passwordPrompt = promptString;
    PasswordPrompt.prompt(MyPromptCallback_TiddlerEncryptionPlugin, context);
    return;
}

function MyPromptCallback_TiddlerEncryptionPlugin(context) {
    if(context.callbackFunction) {
	context.callbackFunction(context);
    } else {
	config.encryptionPasswords[context.passwordPrompt] = context.password;
	story.refreshAllTiddlers(true);
    }
    return;
}

function GetAndSetPasswordForPrompt_TiddlerEncryptionPlugin(promptString) {
    if(!config.encryptionPasswords[promptString]) {
	config.encryptionPasswords[promptString] = MyPrompt_TiddlerEncryptionPlugin(promptString, "");
    }
    return config.encryptionPasswords[promptString]; // may be null, prompt can be cancelled.
}

function GetAndSetPasswordForPromptToDecrypt_TiddlerEncryptionPlugin(promptString) {
    if(config.encryptionReEnterPasswords) {
	return GetAndSetPasswordForPrompt_TiddlerEncryptionPlugin(promptString);
    } else {
	return config.encryptionPasswords[promptString];
    }
}

// Make the encrypted tiddlies look a little more presentable.
function StringToHext_TiddlerEncryptionPlugin(theString) {
    var theResult = "";
    for(var i=0; i<theString.length; i++) {
	var theHex = theString.charCodeAt(i).toString(16);
	if(theHex.length<2) {
	    theResult += "0"+theHex;
	} else {
	    theResult += theHex;
	}
	if(i && i % 32 == 0)
	    theResult += "\n";
    }
    return theResult;
}

function HexToString_TiddlerEncryptionPlugin(theString) {
    var theResult = "";
    for(var i=0; i<theString.length; i+=2) {
	if(theString.charAt(i) == "\n") {
	    i--;	// cause us to skip over the newline and resume
	    continue;
	}
	theResult += String.fromCharCode(parseInt(theString.substr(i, 2),16));
    }
    return theResult;
}
//
// Heavily leveraged from http://trac.tiddlywiki.org/browser/Trunk/contributors/SaqImtiaz/verticals/Hesperian/PasswordPromptPlugin.js  Revision 5635
//
PasswordPrompt ={
  prompt : function(callback,context){
	if (!context) {
	    context = {};
	}
	var box = createTiddlyElement(document.getElementById("contentWrapper"),'div','passwordPromptBox');
	box.innerHTML = store.getTiddlerText('PasswordPromptTemplate');
	box.style.position = 'absolute';
	this.center(box);
	document.getElementById('promptDisplayField').value = context.passwordPrompt;
	var passwordInputField = document.getElementById('passwordInputField');
	passwordInputField.onkeyup = function(ev) {
	    var e = ev || window.event;
	    if(e.keyCode == 10 || e.keyCode == 13) { // Enter
		PasswordPrompt.submit(callback, context);
	    }
	};
	passwordInputField.focus();
	document.getElementById('passwordPromptSubmitBtn').onclick = function(){PasswordPrompt.submit(callback,context);};
	document.getElementById('passwordPromptCancelBtn').onclick = function(){PasswordPrompt.cancel(callback,context);};
    },     
 	       
  center : function(el){
	var size = this.getsize(el);
	el.style.left = (Math.round(findWindowWidth()/2) - (size.width /2) + findScrollX())+'px';
	el.style.top = (Math.round(findWindowHeight()/2) - (size.height /2) + findScrollY())+'px';
    },
 	       
  getsize : function (el){
	var x = {};
	x.width = el.offsetWidth || el.style.pixelWidth;
	x.height = el.offsetHeight || el.style.pixelHeight;
	return x;
    },
 	       
  submit : function(cb,context){
	context.passwordPrompt = document.getElementById('promptDisplayField').value;
	context.password = document.getElementById('passwordInputField').value;
	var box = document.getElementById('passwordPromptBox');
	box.parentNode.removeChild(box);
	cb(context);
	return false;
    },

  cancel : function(cb,context){
	var box = document.getElementById('passwordPromptBox');
	box.parentNode.removeChild(box);
	return false;
    },
 	       
  setStyles : function(){
	setStylesheet(
	    "#passwordPromptBox dd.submit {margin-left:0; font-weight: bold; margin-top:1em;}\n"+
	    "#passwordPromptBox dd.submit .button {padding:0.5em 1em; border:1px solid #ccc;}\n"+
	    "#passwordPromptBox dt.heading {margin-bottom:0.5em; font-size:1.2em;}\n"+
	    "#passwordPromptBox {border:1px solid #ccc;background-color: #eee;padding:1em 2em;}",'passwordPromptStyles');
    },
 	       
  template : '<form action="" onsubmit="return false;" id="passwordPromptForm">\n'+
  '    <dl>\n'+
  '        <dt class="heading">Please enter the password:</dt>\n'+
  '        <dt>Prompt:</dt>\n'+
  '        <dd><input type="text" readonly id="promptDisplayField" class="display"/></dd>\n'+
  '        <dt>Password:</dt>\n'+
  '        <dd><input type="password" tabindex="1" class="input" id="passwordInputField"/></dd>\n'+
  '        <dd class="submit">\n'+
  '            <a tabindex="2" href="javascript:;" class="button" id="passwordPromptSubmitBtn">OK</a>\n'+
  '            <a tabindex="3" href="javascript:;" class="button" id="passwordPromptCancelBtn">Cancel</a>\n'+
  '        </dd>\n'+
  '    </dl>\n'+
  '</form>',
 	                         
  init : function(){
	config.shadowTiddlers.PasswordPromptTemplate = this.template;
	this.setStyles();
    }
};
 	
PasswordPrompt.init();

// http://www.movable-type.co.uk/scripts/tea-block.html
//
// TEAencrypt: Use Corrected Block TEA to encrypt plaintext using password
//             (note plaintext & password must be strings not string objects)
//
// Return encrypted text as string
//
function TEAencrypt(plaintext, password)
{
    if (plaintext.length == 0) return('');  // nothing to encrypt
    // 'escape' plaintext so chars outside ISO-8859-1 work in single-byte packing, but keep
    // spaces as spaces (not '%20') so encrypted text doesn't grow too long (quick & dirty)
    var asciitext = escape(plaintext).replace(/%20/g,' ');
    var v = strToLongs(asciitext);  // convert string to array of longs
    if (v.length <= 1) v[1] = 0;  // algorithm doesn't work for n<2 so fudge by adding a null
    var k = strToLongs(password.slice(0,16));  // simply convert first 16 chars of password as key
    var n = v.length;

    var z = v[n-1], y = v[0], delta = 0x9E3779B9;
    var mx, e, q = Math.floor(6 + 52/n), sum = 0;

    while (q-- > 0) {  // 6 + 52/n operations gives between 6 & 32 mixes on each word
        sum += delta;
        e = sum>>>2 & 3;
        for (var p = 0; p < n; p++) {
            y = v[(p+1)%n];
            mx = (z>>>5 ^ y<<2) + (y>>>3 ^ z<<4) ^ (sum^y) + (k[p&3 ^ e] ^ z);
            z = v[p] += mx;
        }
    }

    var ciphertext = longsToStr(v);

    return escCtrlCh(ciphertext);
}

//
// TEAdecrypt: Use Corrected Block TEA to decrypt ciphertext using password
//
function TEAdecrypt(ciphertext, password)
{
    if (ciphertext.length == 0) return('');
    var v = strToLongs(unescCtrlCh(ciphertext));
    var k = strToLongs(password.slice(0,16)); 
    var n = v.length;

    var z = v[n-1], y = v[0], delta = 0x9E3779B9;
    var mx, e, q = Math.floor(6 + 52/n), sum = q*delta;

    while (sum != 0) {
        e = sum>>>2 & 3;
        for (var p = n-1; p >= 0; p--) {
            z = v[p>0 ? p-1 : n-1];
            mx = (z>>>5 ^ y<<2) + (y>>>3 ^ z<<4) ^ (sum^y) + (k[p&3 ^ e] ^ z);
            y = v[p] -= mx;
        }
        sum -= delta;
    }

    var plaintext = longsToStr(v);

    // strip trailing null chars resulting from filling 4-char blocks:
    plaintext = plaintext.replace(/\0+$/,'');

    return unescape(plaintext);
}


// supporting functions

function strToLongs(s) {  // convert string to array of longs, each containing 4 chars
    // note chars must be within ISO-8859-1 (with Unicode code-point < 256) to fit 4/long
    var l = new Array(Math.ceil(s.length/4));
    for (var i=0; i<l.length; i++) {
        // note little-endian encoding - endianness is irrelevant as long as 
        // it is the same in longsToStr() 
        l[i] = s.charCodeAt(i*4) + (s.charCodeAt(i*4+1)<<8) + 
               (s.charCodeAt(i*4+2)<<16) + (s.charCodeAt(i*4+3)<<24);
    }
    return l;  // note running off the end of the string generates nulls since 
}              // bitwise operators treat NaN as 0

function longsToStr(l) {  // convert array of longs back to string
    var a = new Array(l.length);
    for (var i=0; i<l.length; i++) {
        a[i] = String.fromCharCode(l[i] & 0xFF, l[i]>>>8 & 0xFF, 
                                   l[i]>>>16 & 0xFF, l[i]>>>24 & 0xFF);
    }
    return a.join('');  // use Array.join() rather than repeated string appends for efficiency
}

function escCtrlCh(str) {  // escape control chars etc which might cause problems with encrypted texts
    return str.replace(/[\0\t\n\v\f\r\xa0'"!]/g, function(c) { return '!' + c.charCodeAt(0) + '!'; });
}

function unescCtrlCh(str) {  // unescape potentially problematic nulls and control characters
    return str.replace(/!\d\d?\d?!/g, function(c) { return String.fromCharCode(c.slice(1,-1)); });
}

//}}}
/***
|Name|TiddlerEncryptionPlugin|
|Author|Lyall Pearce|
|Source|http://www.Remotely-Helpful.com/TiddlyWiki/TiddlerEncryptionPlugin.html|
|License|[[Creative Commons Attribution-Share Alike 3.0 License|http://creativecommons.org/licenses/by-sa/3.0/]]|
|Version|2.0.1|
|~CoreVersion|2.3.0|
|Requires|None|
|Overrides|store.getSaver().externalizeTiddler(), store.getTiddler() and store.getTiddlerText()|
|Description|Encrypt/Decrypt Tiddlers with a Password key|

!!!!!Usage
<<<
* Tag a tiddler with Encrypt(prompt)
** Consider the 'prompt' something to help you remember the password with. If multiple tiddlers can be encrypted with the same 'prompt' and you will only be asked for the password once.
* Upon save, the Tiddler will be encrypted and the tag replaced with Decrypt(prompt).
** Failure to encrypt (by not entering a password) will leave the tiddler unencrypted and will leave the Encrypt(prompt) tag in place. This means that the next time you save, you will be asked for the password again.
** To have multiple tiddlers use the same password - simply use the same 'prompt'.
** Tiddlers that are encrypted may be tagged 'excludeSearch' as there is no point in searching encrypted data - this is configurable by an option - you still may want to search the titles of encrypted tiddlers
** Tiddlers that are encrypted may be tagged 'excludeLists', as activities that list tiddlers may trigger password prompting when none was desired - this is configurable by an option.
** Automatic removal of excludeLists and excludeSearch tags is performed, if the above two options are set, only if these two tags are the last 2 tags for a tiddler.
** Encrypted tiddlers are stored as displayable hex, to keep things visibly tidy, should you display an encrypted tiddler. There is nothing worse than seeing a pile of gobbledy gook on your screen. Additionally, the encrypted data is easily cut/paste/emailed if displayed in hex form.
* Tiddlers are decrypted on initial display, not when you load the TiddlyWiki
** If you don't display a tiddler, you won't decrypt it (unless you use the {{{<<EncryptionDecryptAll>>}}} macro)
** Tiddlers will re-encrypt automatically on save.
** Decryption of Tiddlers does not make your TiddlyWiki 'dirty' - you will not be asked to save if you leave the page.
* Errors are reported via diagnostic messages.
** Empty passwords, on save, will result in the tiddler being saved unencrypted - this should only occur with new tiddlers, decrypted tiddlers or with tiddlers who have had their 'prompt' tag changed.
** Encrypted tiddlers know if they are decrypted successfully - failure to decrypt a tiddler will ''not'' lose your data.
** Editing of an encrypted (that has not been unencrypted) tiddler will result in loss of that tiddler as the SHA1 checksums will no longer match, upon decryption. To this end, it is best that you do not check the option.
** To change the password on a Tiddler, change the Encrypt('prompt') tag to a new prompt value, after decrypting the tiddler.
** You can edit the tags of an encrypted tiddler, so long as you do not edit the text.
** To change the password for all tiddlers of a particular prompt, use the {{{<<EncryptionChangePassword ["button text" ["tooltip text" ["prompt string" ["accessKey"]]]]>>}}} macro.
** To decrypt all tiddlers of a particular "prompt string", use the {{{<<EncryptionDecryptAll ["button text" ["tooltip text" ["prompt string" ["accessKey"]]]]>>}}} macro - this will make tiddlers encrypted with "prompt string" searchable - or prompt for all 'prompt strings', if none is supplied.
<<<
!!!!!Configuration
<<<
Useful Buttons: 
<<EncryptionChangePassword>> - Change passwords of encrypted tiddlers.
<<EncryptionDecryptAll>> - Decrypt ALL tiddlers - enables searching contents of encrypted tiddlers.
<<option chkExcludeEncryptedFromSearch>> - If set, Encrypted Tiddlers are excluded from searching by tagging with excludeSearch. If Clear, excludeSearch is not added and it is also removed from existing Encrypted Tiddlers only if it is the last Tag. Searching of Encrypted Tiddlers is only meaningful for the Title and Tags.
<<option chkExcludeEncryptedFromLists>> - If set, Encrypted Tiddlers are excluded from lists by tagging with excludeLists. If Clear, excludeLists is not added and it is also removed from existing Encrypted Tiddlers only if it is the last Tag. Preventing encrypted tiddlers from appearing in lists effectively hides them.
<<option chkCachePasswords>> - If unchecked, do not cache passwords. This means you will be prompted for the password every time you display an encrypted tiddler (not forgetting that once they are displayed, they stay decrypted until the next save).
<<<
!!!!!Revision History
<<<
* 2.0.1 - Fixed the obscure decryption problem if an encrypted tiddler was a certain length.
* 2.0.0 - No longer display encrypted tiddler contents, display a button which will decrypt the tiddler. Additionally, do not automatically prompt for passwords - rely on either the Decrypt or DecryptAll buttons to intitiate a prompt for passwords. This is the only change in behaviour, if you don't like this behaviour, don't upgrade from 1.10.2
<<<
!!!!!Additional work

***/
//{{{
version.extensions.TiddlerEncryptionPlugin = {major: 2, minor: 0, revision: 1, date: new Date(2008,10,6)};

// where I cache the passwords - for want of a better place.
config.encryptionPasswords = new Array();
config.encryptionReEnterPasswords = false;

if(config.options.chkExcludeEncryptedFromSearch == undefined) config.options.chkExcludeEncryptedFromSearch = false;
if(config.options.chkExcludeEncryptedFromLists == undefined) config.options.chkExcludeEncryptedFromLists = false;
if(config.options.chkCachePasswords == undefined) config.options.chkCachePasswords = true;

config.macros.EncryptionChangePassword = {};
config.macros.EncryptionChangePassword.handler = function(place,macroName,params,wikifier,paramString,tiddler) {
    var theButton = createTiddlyButton(place,
				       (params[0] && params[0].length > 0) ? params[0] : "Change Passwords", 
				       (params[1] && params[1].length > 0) ? params[1] : "Change Passwords" + (params[2] ? " for prompt "+params[2] : ""), 
				       onClickEncryptionChangePassword,
				       null,
				       null,
				       params[3]);
    if(params[2] && params[2].length > 0) {
	theButton.setAttribute("promptString", params[2]);
    }
};

config.macros.EncryptionDecryptAll = {};
config.macros.EncryptionDecryptAll.handler = function(place,macroName,params,wikifier,paramString,tiddler) {
    var theButton = createTiddlyButton(place,
				       (params[0] && params[0].length > 0) ? params[0] : "Decrypt All", 
				       (params[1] && params[1].length > 0) ? params[1] : "Decrypt All Tiddlers" + ((params[2] && params[2].length > 0) ? " for prompt "+params[2] : " for a given 'prompt string'"), 
				       onClickEncryptionDecryptAll,
				       null,
				       null,
				       params[3]);
    if(params[2] && params[2].length > 0) {
	theButton.setAttribute("promptString", params[2]);
    }
};

config.macros.EncryptionDecryptThis = {};
config.macros.EncryptionDecryptThis.handler = function(place,macroName,params,wikifier,paramString,tiddler) {
    var theButton = createTiddlyButton(place,
				       (params[0] && params[0].length > 0) ? params[0] : "Decrypt", 
				       (params[1] && params[1].length > 0) ? params[1] : "Decrypt this Tiddler", 
				       onClickEncryptionDecryptThis,
				       null,
				       null,
				       params[3]);
    if(params[2] && params[2].length > 0) {
	theButton.setAttribute("theTiddler", params[2]);
    }
};

function onClickEncryptionChangePassword() {
    // Prompt for 'prompt string'
    
    var promptString = this.getAttribute("promptString");
    if(!promptString) {
	promptString = prompt("Enter 'prompt string' to change password for:","");
    }
    if(!promptString) {
	return;
    }
    // Prompt for 'old password'
    var oldPassword = GetAndSetPasswordForPrompt_TiddlerEncryptionPlugin(promptString);
    if(!oldPassword) {
	return;
    }
    // Decrypt ALL tiddlers for that prompt
    var decryptTag = "Decrypt("+promptString+")";
    var tiddlersToDecrypt = store.getTaggedTiddlers(decryptTag);
    try {
	for(var ix=0; ix<tiddlersToDecrypt.length; ix++) {
	    CheckTiddlerForDecryption_TiddlerEncryptionPlugin(tiddlersToDecrypt[ix]);
	}
    } catch (e) {
	if(e == "DecryptionFailed") {
	    displayMessage("Password incorrect.");
	    return;
	} else {
	    throw e;
	}
    }
    var newPassword = MyPrompt_TiddlerEncryptionPlugin("Enter new password for '"+promptString+"'", "");
    if(newPassword) {
	var newPasswordAgain = MyPrompt_TiddlerEncryptionPlugin("Enter new password, again, for '"+promptString+"'", "");
	if(newPasswordAgain && newPassword == newPasswordAgain) {
	    if(config.optionsDesc.chkCachePasswords == false) {
		config.encryptionPasswords[promptString] = newPasswordAgain;
	    }
	    displayMessage("Password for '"+promptString+"' updated.");
	}
    }
    store.setDirty(true);
    autoSaveChanges();
    return;
};

function onClickEncryptionDecryptThis() {
    var theTiddler = this.getAttribute("theTiddler");
    if(!theTiddler) {
	return;
    }
    config.encryptionReEnterPasswords = true;
    try {
	theTiddler = store.getTiddler(theTiddler);
	config.encryptionReEnterPasswords = false;
	story.refreshAllTiddlers();
    } catch (e) {
	if(e == "DecryptionFailed") {
	    displayMessage("Decryption failed");
	    return;
	}
    } // catch
    return;
};

function onClickEncryptionDecryptAll() {
    var promptString = this.getAttribute("promptString");
    if(!promptString) {
	promptString = "";
    }
    var tagToSearchFor="Decrypt("+promptString;
    config.encryptionReEnterPasswords = true; 
    try {
	store.forEachTiddler(function(store,tiddler) {
		if(tiddler && tiddler.tags) {
		    for(var ix=0; ix<tiddler.tags.length; ix++) {
			if(tiddler.tags[ix].indexOf(tagToSearchFor) == 0) {
			    try {
				CheckTiddlerForDecryption_TiddlerEncryptionPlugin(tiddler);
			    } catch (e) {
				displayMessage("Decryption of '"+tiddler.title+"' failed.");
				throw e;
			    }
			} // if(tiddler.tags
		    } // for
		} // if
	    }); // store.forEachTiddler
	displayMessage("All encrypted tiddlers have been decrypted" + (promptString != "" ? "for '"+promptString+"'" : ""));
    } catch (e) {
	if(e == "DecryptionFailed") {
	    return;
	}
    } // catch
    return;
};

store.getSaver().externalizeTiddler_TiddlerEncryptionPlugin = store.getSaver().externalizeTiddler;
store.getSaver().externalizeTiddler = function(store, tiddler) {
    // Ok, got the tiddler, track down the passwordPrompt in the tags.
    // track down the Encrypt(passwordPrompt) tag
    if(tiddler && tiddler.tags) {
	for(var g=0; g<tiddler.tags.length; g++) {
	    var tag = tiddler.tags[g];
	    if(tag.indexOf("Encrypt(") == 0) {
		var lastBracket=tag.lastIndexOf(")");
		if(lastBracket >= 0) {
		    // Ok, tagged with Encrypt(passwordPrompt)
		    // extract the passwordPrompt name
		    var passwordPrompt=tag.substring(8,lastBracket);
		    // Ok, Encrypt this tiddler!
		    var decryptedSHA1 = Crypto.hexSha1Str(tiddler.text);
		    var password =  GetAndSetPasswordForPrompt_TiddlerEncryptionPlugin(passwordPrompt);
		    if(password) {
			var encryptedText = TEAencrypt(tiddler.text, password);
			encryptedText = StringToHext_TiddlerEncryptionPlugin(encryptedText);
			tiddler.text = "Encrypted("+decryptedSHA1+")\n"+encryptedText;
			// Replace the Tag with the Decrypt() tag
			tiddler.tags[g]="Decrypt("+passwordPrompt+")";
			// prevent searches on encrypted tiddlers, still nice to search on title though.
			if(config.options.chkExcludeEncryptedFromSearch == true) {
			    tiddler.tags.push("excludeSearch");
			}
			// prevent lists of encrypted tiddlers
			if(config.options.chkExcludeEncryptedFromLists == true) {
			    tiddler.tags.push("excludeLists");
			}
			tiddler.changed();
			// let the store know it's dirty
			store.setDirty(tiddler.title, true);
		    } else {
			// do not encrypt - no password entered
		    }
		    break;
		} // if (lastBracket...
	    } // if(tag.indexOf(...
	} // for(var g=0;...
    } // if(tiddler.tags...
    
    // Then, finally, do the save by calling the function we override.

    return store.getSaver().externalizeTiddler_TiddlerEncryptionPlugin(store, tiddler);
};

function CheckTiddlerForDecryption_TiddlerEncryptionPlugin(tiddler) {
    if(tiddler && tiddler.tags) {
	for(var g=0; g<tiddler.tags.length; g++) {
	    var tag = tiddler.tags[g];
	    if(tag.indexOf("Decrypt(") == 0) {
		var lastBracket=tag.lastIndexOf(")");
		if(lastBracket >= 0) {
		    if(tiddler.text.substr(0,10) == "Encrypted(") {
			var closingSHA1Bracket = tiddler.text.indexOf(")");
			var decryptedSHA1 = tiddler.text.substring(10, closingSHA1Bracket);
			// Ok, tagged with Decrypt(passwordPrompt)
			// extract the passwordPrompt name
			var passwordPrompt=tag.substring(8,lastBracket);
			// Ok, Decrypt this tiddler!
			var decryptedText = tiddler.text.substr(closingSHA1Bracket+2);
			decryptedText = HexToString_TiddlerEncryptionPlugin(decryptedText);
                        // prompt("Decryption request for Tiddler '"+tiddler.title+"'");
			var password = GetAndSetPasswordForPromptToDecrypt_TiddlerEncryptionPlugin(passwordPrompt);
			if(password) {
			    decryptedText = TEAdecrypt(decryptedText, password );
			    var thisDecryptedSHA1 = Crypto.hexSha1Str(decryptedText);
			    if(decryptedSHA1 == thisDecryptedSHA1) {
				tiddler.text = decryptedText;
				// Replace the Tag with the Encrypt() tag
				tiddler.tags[g]="Encrypt("+passwordPrompt+")";
				if(tiddler.tags[tiddler.tags.length-1] == 'excludeLists') {
				    // Remove exclude lists only if it's the last entry
				    // as it's automatically put there by encryption
				    tiddler.tags.length--;
				}
				if(tiddler.tags[tiddler.tags.length-1] == 'excludeSearch') {
				    // Remove exclude search only if it's the last entry
				    // as it's automatically put there by encryption
				    tiddler.tags.length--;
				}
				tiddler.changed();
			    } else {
				// Did not decrypt, discard the password from the cache
				config.encryptionPasswords[passwordPrompt] = null;
				config.encryptionReEnterPasswords = false;
				throw "DecryptionFailed";
			    }
			} else {
			    // no password supplied, dont bother trying to decrypt
			    config.encryptionReEnterPasswords = false;
			    throw "DecryptionFailed";
			}
		    } else {
			// Tagged as encrypted but not expected format, just leave it unchanged
		    }
		    break; // out of for loop
		} // if (lastBracket...
	    } // if(tag.indexOf(...
	} // for(var g=0;...
    } // if (tiddler && tags)
    return tiddler;
};

store.getTiddler_TiddlerEncryptionPlugin = store.getTiddler;
store.getTiddler = function(title) {
    var tiddler = store.getTiddler_TiddlerEncryptionPlugin(title);
    if(tiddler) { // shadow tiddlers are not expected to be encrypted.
	try {
	    return CheckTiddlerForDecryption_TiddlerEncryptionPlugin(tiddler);
	} catch (e) {
	    if(e == "DecryptionFailed") {
		var tiddler = store.getTiddler("DecryptionFailed");
		if(!tiddler) {
		    tiddler = new Tiddler();
		    tiddler.set(title,
				"<<EncryptionDecryptThis \"Decrypt\" \"Decrypt this tiddler\" \""+title+"\">>",
				config.views.wikified.shadowModifier,
				version.date,[],version.date);
		} 
		return tiddler;
	    } // if(e)
	} // catch
    } // if(tiddler) {
    return null;
};

store.getTiddlerText_TiddlerEncryptionPlugin = store.getTiddlerText;
store.getTiddlerText = function(title,defaultText) {
    // Simply retrieve the tiddler, normally, if it requires decryption, it will be decrypted
    var decryptedTiddler = store.getTiddler(title);
    if(decryptedTiddler) {
	return decryptedTiddler.text;
    }
    //Ok, rather than duplicate all the core code, the above code should fail if we reach here
    // let the core code take over.
    return  store.getTiddlerText_TiddlerEncryptionPlugin(title,defaultText);
};

// Given a prompt, search our cache to see if we have already entered the password.
// Can return null if the user enters nothing.
function MyPrompt_TiddlerEncryptionPlugin(promptString,defaultValue) {
    var thePassword = defaultValue;
    return prompt(promptString, defaultValue);
}

function GetAndSetPasswordForPrompt_TiddlerEncryptionPlugin(promptString) {
    if(!config.encryptionPasswords[promptString]) {
	config.encryptionPasswords[promptString] = MyPrompt_TiddlerEncryptionPlugin("Enter password for '"+promptString+"' :", "");
    }
    return config.encryptionPasswords[promptString]; // may be null, prompt can be cancelled.
}

function GetAndSetPasswordForPromptToDecrypt_TiddlerEncryptionPlugin(promptString) {
    if(config.encryptionReEnterPasswords) {
	if(config.options.chkCachePasswords == true) {
	    return GetAndSetPasswordForPrompt_TiddlerEncryptionPlugin(promptString);
	} else {
	    config.encryptionPasswords[promptString] = MyPrompt_TiddlerEncryptionPlugin("Enter password for '"+promptString+"' :", "");
	    return config.encryptionPasswords[promptString];
	}
    } else {
	return;
    }
}

// Make the encrypted tiddlies look a little more presentable.
function StringToHext_TiddlerEncryptionPlugin(theString) {
    var theResult = "";
    for(var i=0; i<theString.length; i++) {
	var theHex = theString.charCodeAt(i).toString(16);
	if(theHex.length<2) {
	    theResult += "0"+theHex;
	} else {
	    theResult += theHex;
	}
	if(i && i % 32 == 0)
	    theResult += "\n";
    }
    return theResult;
}
function HexToString_TiddlerEncryptionPlugin(theString) {
    var theResult = "";
    for(var i=0; i<theString.length; i+=2) {
	if(theString.charAt(i) == "\n") {
	    i--;	// cause us to skip over the newline and resume
	    continue;
	}
	theResult += String.fromCharCode(parseInt(theString.substr(i, 2),16));
    }
    return theResult;
}

// http://www.movable-type.co.uk/scripts/tea-block.html
//
// TEAencrypt: Use Corrected Block TEA to encrypt plaintext using password
//             (note plaintext & password must be strings not string objects)
//
// Return encrypted text as string
//
function TEAencrypt(plaintext, password)
{
    if (plaintext.length == 0) return('');  // nothing to encrypt
    // 'escape' plaintext so chars outside ISO-8859-1 work in single-byte packing, but keep
    // spaces as spaces (not '%20') so encrypted text doesn't grow too long (quick & dirty)
    var asciitext = escape(plaintext).replace(/%20/g,' ');
    var v = strToLongs(asciitext);  // convert string to array of longs
    if (v.length <= 1) v[1] = 0;  // algorithm doesn't work for n<2 so fudge by adding a null
    var k = strToLongs(password.slice(0,16));  // simply convert first 16 chars of password as key
    var n = v.length;

    var z = v[n-1], y = v[0], delta = 0x9E3779B9;
    var mx, e, q = Math.floor(6 + 52/n), sum = 0;

    while (q-- > 0) {  // 6 + 52/n operations gives between 6 & 32 mixes on each word
        sum += delta;
        e = sum>>>2 & 3;
        for (var p = 0; p < n; p++) {
            y = v[(p+1)%n];
            mx = (z>>>5 ^ y<<2) + (y>>>3 ^ z<<4) ^ (sum^y) + (k[p&3 ^ e] ^ z);
            z = v[p] += mx;
        }
    }

    var ciphertext = longsToStr(v);

    return escCtrlCh(ciphertext);
}

//
// TEAdecrypt: Use Corrected Block TEA to decrypt ciphertext using password
//
function TEAdecrypt(ciphertext, password)
{
    if (ciphertext.length == 0) return('');
    var v = strToLongs(unescCtrlCh(ciphertext));
    var k = strToLongs(password.slice(0,16)); 
    var n = v.length;

    var z = v[n-1], y = v[0], delta = 0x9E3779B9;
    var mx, e, q = Math.floor(6 + 52/n), sum = q*delta;

    while (sum != 0) {
        e = sum>>>2 & 3;
        for (var p = n-1; p >= 0; p--) {
            z = v[p>0 ? p-1 : n-1];
            mx = (z>>>5 ^ y<<2) + (y>>>3 ^ z<<4) ^ (sum^y) + (k[p&3 ^ e] ^ z);
            y = v[p] -= mx;
        }
        sum -= delta;
    }

    var plaintext = longsToStr(v);

    // strip trailing null chars resulting from filling 4-char blocks:
    plaintext = plaintext.replace(/\0+$/,'');

    return unescape(plaintext);
}


// supporting functions

function strToLongs(s) {  // convert string to array of longs, each containing 4 chars
    // note chars must be within ISO-8859-1 (with Unicode code-point < 256) to fit 4/long
    var l = new Array(Math.ceil(s.length/4));
    for (var i=0; i<l.length; i++) {
        // note little-endian encoding - endianness is irrelevant as long as 
        // it is the same in longsToStr() 
        l[i] = s.charCodeAt(i*4) + (s.charCodeAt(i*4+1)<<8) + 
               (s.charCodeAt(i*4+2)<<16) + (s.charCodeAt(i*4+3)<<24);
    }
    return l;  // note running off the end of the string generates nulls since 
}              // bitwise operators treat NaN as 0

function longsToStr(l) {  // convert array of longs back to string
    var a = new Array(l.length);
    for (var i=0; i<l.length; i++) {
        a[i] = String.fromCharCode(l[i] & 0xFF, l[i]>>>8 & 0xFF, 
                                   l[i]>>>16 & 0xFF, l[i]>>>24 & 0xFF);
    }
    return a.join('');  // use Array.join() rather than repeated string appends for efficiency
}

function escCtrlCh(str) {  // escape control chars etc which might cause problems with encrypted texts
    return str.replace(/[\0\t\n\v\f\r\xa0'"!]/g, function(c) { return '!' + c.charCodeAt(0) + '!'; });
}

function unescCtrlCh(str) {  // unescape potentially problematic nulls and control characters
    return str.replace(/!\d\d?\d?!/g, function(c) { return String.fromCharCode(c.slice(1,-1)); });
}

//}}}