Privacy/Features/DOMCryptAPI/UseCases: Difference between revisions

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=== Messaging ===
=== Messaging ===


* Natasha and Boris would like to message one another privately via a web application. The server is untrusted and all message data that Natasha sends to the server should be encrypted so only Boris can read it after downloading. A server compromise will net the server's attacker only blobs of useless data. This web application will use the Public Key API: '''window.cipher.pk.*'''  
* Deuxdrop ( https://wiki.mozilla.org/Labs/Deuxdrop ), a project from Mozilla Labs would benefit from the DOMCrypt API.
* Boot2Gecko apps will benefit greatly from the DOMCrypt API, as the only thing to consume is the DOM and all of the APIs we provide.
** Example: Natasha and Boris would like to message one another privately via a web application. The server is untrusted and all message data that Natasha sends to the server should be encrypted so only Boris can read it after downloading. A server compromise will net the server's attacker only blobs of useless data. This web application will use the Public Key API: '''window.cipher.pk.*'''  


Example Code:
Example Code:
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var plainText = "Hey, wanna grab a root beer with me after work?";
var plainText = "Hey, wanna grab a root beer with me after work?";


window.cipher.pk.encrypt(plainText, publicKey, function callback(aCipherMessage) {
window.crypto.pk.encrypt(plainText, publicKey, function callback(aCipherMessage) {
   // Asynchronous crypto API - the plainText is encrypted and the CipherMessage object is returned to this callback function
   // Asynchronous crypto API - the plainText is encrypted and the CipherMessage object is returned to this callback function
   // aCipherMessage is a JS object literal:  
   // aCipherMessage is a JS object literal:  
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</pre>
</pre>


=== General Purpose Symmetric Crypto ===
=== Symmetric Crypto via Diffie-Hellman Key Exchange ===


* A web developer would like to use localStorage or IndexedDB in her diary web application, but would really like all data stored locally to be encrypted should the machine get stolen or 'borrowed' by an unauthorized user.
* TBD
 
Example Code uses the symmetric encryption API: '''window.cipher.sym.*'''


<pre class="brush:js;toolbar:false;">
<pre class="brush:js;toolbar:false;">
// create an encryption key and keep it around for later use - perhaps it is also saved to the server...
  // This API is under development
 
window.cipher.sym.generateKey(function callback(key){
  document.currentKey = key;
  diaryApp.saveKeyToServer(key);
});
 
// save the current diary entry:
var diaryEntry = document.getElementById("diary-entry").textContent;
 
window.cipher.sym.encrypt(diaryEntry, document.currentKey, function callback(cipherText) {
  var entryID = diaryApp.getSequence();
  localStorage.setItem(entryID, cipherText);
  alert("Diary entry saved successfully");
});
 
// decryption
 
window.cipher.sym.decrypt(localStorage.getItem(entryID), document.currentKey, function callback(plainText) {
  document.getElementById("diary-entry").textContent = plainText;
});
</pre>
</pre>


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SHA 256 hashes are handy for storing passwords and generating checksums (among other uses)
SHA 256 hashes are handy for storing passwords and generating checksums (among other uses)


Example code uses the hashing API: '''window.cipher.hash.*'''
Example code uses the hashing API, using the constructor '''window.crypto.hash'''


<pre class="brush:js;toolbar:false;">
<pre class="brush:js;toolbar:false;">
var myPassword = "5ekr3tPa55w0rd";


window.cipher.hash.SHA256(myPassword, function callback(aHash) {
var hasher = new window.crypto.hash("RS256");
   myApp.doSomethingWithAHash(aHash);
var myData = "1234567890abcdefghijklmnopqrstuwxyz";
});
var arrBufferView = new Int8Array(myData.length);
 
for (var i = 0; i < myData.length; i++) {
   arrBufferView[i] = myData.charCodeAt(i);
}
 
hasher.append(arrBufferView);
 
var hashed = hasher.finish();


// Another idea: generating a file checksum in conjunction with the FileAPI
// Another idea: generating a file checksum in conjunction with the FileAPI
</pre>
</pre>
=== Identity in the Browser ===
We will need both a chrome-privileged and content Crypto API for generating keypairs and hashing data. See [[Identity/Verified_Email_Protocol/Latest]]


== New Ideas ==
== New Ideas ==

Latest revision as of 18:40, 6 December 2011

DOMCrypt API Use Cases

Back to DOMCrypt Draft Spec: https://wiki.mozilla.org/Privacy/Features/DOMCryptAPISpec/Latest

Messaging

  • Deuxdrop ( https://wiki.mozilla.org/Labs/Deuxdrop ), a project from Mozilla Labs would benefit from the DOMCrypt API.
  • Boot2Gecko apps will benefit greatly from the DOMCrypt API, as the only thing to consume is the DOM and all of the APIs we provide.
    • Example: Natasha and Boris would like to message one another privately via a web application. The server is untrusted and all message data that Natasha sends to the server should be encrypted so only Boris can read it after downloading. A server compromise will net the server's attacker only blobs of useless data. This web application will use the Public Key API: window.cipher.pk.*

Example Code: 

var publicKey = messagingApp.getPublicKey("boris");

var plainText = "Hey, wanna grab a root beer with me after work?";

window.crypto.pk.encrypt(plainText, publicKey, function callback(aCipherMessage) {
  // Asynchronous crypto API - the plainText is encrypted and the CipherMessage object is returned to this callback function
  // aCipherMessage is a JS object literal: 
  //   { content: <ENCRYPTED, BASE64 Encoded String>, 
  //     pubKey: <PUBLICKEY used to encrypt the a symmetric key>, 
  //     wrappedKey: <SYMMETRIC KEY wrapped with the recipient's public key>,
  //     iv: <Initialization Vector> 
  //   }
  messagingApp.sendMessage(aCipherMessage, {from: 'natasha', to: 'boris'});
});

Symmetric Crypto via Diffie-Hellman Key Exchange

  • TBD
  // This API is under development

Hashing

SHA 256 hashes are handy for storing passwords and generating checksums (among other uses)

Example code uses the hashing API, using the constructor window.crypto.hash 


var hasher = new window.crypto.hash("RS256");
var myData = "1234567890abcdefghijklmnopqrstuwxyz";
var arrBufferView = new Int8Array(myData.length);

for (var i = 0; i < myData.length; i++) {
  arrBufferView[i] = myData.charCodeAt(i);
}

hasher.append(arrBufferView);

var hashed = hasher.finish();

// Another idea: generating a file checksum in conjunction with the FileAPI

New Ideas

  • Some ideas that have been mentioned via mailing lists, etc.

An API to make <keygen> easier

  • Jonas Sicking mentioned this to me during a Mozilla All-hands DOMCrypt presentation
    • NEED EXAMPLE

Signing APIs that would allow S. Korean web users to use any browser for online banking

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