From ec0685829ee5fdcac0ce7bb364aebb268fd10836 Mon Sep 17 00:00:00 2001
From: Tankred Hase <mail@tankredhase.de>
Date: Thu, 4 Apr 2013 21:36:29 +0200
Subject: [PATCH] implemented asymmetric nacl crypto and unit test

---
 src/js/crypto/nacl-crypto.js      | 61 +++++++++++++++++++++++++------
 src/test/unit/nacl-crypto-test.js | 29 ++++++---------
 2 files changed, 62 insertions(+), 28 deletions(-)

diff --git a/src/js/crypto/nacl-crypto.js b/src/js/crypto/nacl-crypto.js
index 661f967..64829cc 100644
--- a/src/js/crypto/nacl-crypto.js
+++ b/src/js/crypto/nacl-crypto.js
@@ -5,25 +5,64 @@ app.crypto.NaclCrypto = function() {
 	'use strict';
 
 	/**
-	 * Encrypt a String with the provided keysize (e.g. 128, 256)
-	 * @param plaintext [String] The input string in UTF8
-	 * @param key [String] The base64 encoded key
-	 * @param iv [String] The base64 encoded IV
-	 * @return [String] The base64 encoded ciphertext
+	 * Generates a baes64 encoded keypair for use with NaCl
 	 */
-	this.encrypt = function(plaintext, key, iv) {
-
+	this.generateKeypair = function(seed) {
+		if (seed) {
+			return null; // TODO: generate from PBKDF2
+		} else {
+			var keys = nacl.crypto_box_keypair();
+			return {
+				boxPk: window.btoa(nacl.decode_latin1(keys.boxPk)),
+				boxSk: window.btoa(nacl.decode_latin1(keys.boxSk))
+			};
+		}
 	};
 
 	/**
-	 * Decrypt a String with the provided keysize (e.g. 128, 256)
+	 * Asymmetrically encrypt a String
+	 * @param plaintext [String] The input string in UTF8
+	 * @param recipientBoxPk [String] The receiver's base64 encoded public key
+	 * @param senderBoxSk [String] The sender's base64 encoded private key
+	 * @return [Object] The base64 encoded ciphertext and nonce
+	 */
+	this.asymmetricEncrypt = function(plaintext, recipientBoxPk, senderBoxSk) {
+		// convert to Uint8Array
+		var ptBuf = nacl.encode_utf8(plaintext);
+		var recipientBoxPkBuf = nacl.encode_latin1(window.atob(recipientBoxPk));
+		var senderBoxSkBuf = nacl.encode_latin1(window.atob(senderBoxSk));
+		// generate nonce
+		var nonce = nacl.crypto_secretbox_random_nonce();
+
+		var ct = nacl.crypto_box(ptBuf, nonce, recipientBoxPkBuf, senderBoxSkBuf);
+		var ctBase64 = window.btoa(nacl.decode_latin1(ct));
+		var nonceBase64 = window.btoa(nacl.decode_latin1(nonce));
+
+		return {
+			ct: ctBase64,
+			nonce: nonceBase64
+		};
+	};
+
+	/**
+	 * Asymmetrically decrypt a String
 	 * @param ciphertext [String] The base64 encoded ciphertext
-	 * @param key [String] The base64 encoded key
-	 * @param iv [String] The base64 encoded IV
+	 * @param nonce [String] The base64 encoded nonce
+	 * @param senderBoxPk [String] The sender's base64 encoded public key
+	 * @param recipientBoxSk [String] The receiver's base64 encoded private key
 	 * @return [String] The decrypted plaintext in UTF8
 	 */
-	this.decrypt = function(ciphertext, key, iv) {
+	this.asymmetricDecrypt = function(ciphertext, nonce, senderBoxPk, recipientBoxSk) {
+		// convert to Uint8Array
+		var ctBuf = nacl.encode_latin1(window.atob(ciphertext));
+		var nonceBuf = nacl.encode_latin1(window.atob(nonce));
+		var senderBoxPkBuf = nacl.encode_latin1(window.atob(senderBoxPk));
+		var recipientBoxSkBuf = nacl.encode_latin1(window.atob(recipientBoxSk));
 
+		var pt = nacl.crypto_box_open(ctBuf, nonceBuf, senderBoxPkBuf, recipientBoxSkBuf);
+		var ptStr = nacl.decode_utf8(pt);
+
+		return ptStr;
 	};
 
 };
\ No newline at end of file
diff --git a/src/test/unit/nacl-crypto-test.js b/src/test/unit/nacl-crypto-test.js
index 01c46af..52bb870 100644
--- a/src/test/unit/nacl-crypto-test.js
+++ b/src/test/unit/nacl-crypto-test.js
@@ -10,33 +10,28 @@ test("Init", 1, function() {
 	ok(nacl_test.util, 'Util');
 	// generate test data
 	nacl_test.test_message = new TestData().generateBigString(1000);
+	nacl_test.crypto = new app.crypto.NaclCrypto();
 });
 
-test("Generate Keypiar", 1, function() {
+test("Generate Keypair", 2, function() {
 	// generate keypair from seed
-	var keys = nacl.crypto_box_keypair();
-	ok(keys.boxSk && keys.boxPk, "Keysize: " + keys.boxPk.length);
-	nacl_test.keys = keys;
+	var senderKeypair = nacl_test.crypto.generateKeypair();
+	ok(senderKeypair.boxSk && senderKeypair.boxPk, "Sender keypair: " + JSON.stringify(senderKeypair));
+	var recipientKeypair = nacl_test.crypto.generateKeypair();
+	ok(recipientKeypair.boxSk && recipientKeypair.boxPk, "Receiver keypair: " + JSON.stringify(recipientKeypair));
+
+	nacl_test.senderKeypair = senderKeypair;
+	nacl_test.recipientKeypair = recipientKeypair;
 });
 
 test("En/Decrypt", 2, function() {
-	var naclCrypto = new app.crypto.NaclCrypto();
-
 	var plaintext = nacl_test.test_message;
-	// var key = nacl_test.util.random(nacl_test.keySize);
-	// var iv = nacl_test.util.random(104);
 
-	// convert utf8 string to Uint8Array 
-	var pt = nacl.encode_utf8(plaintext);
-	// generate nonce
-	var nonce = nacl.crypto_secretbox_random_nonce();
 	// encrypt
-	var ct = nacl.crypto_secretbox(pt, nonce, nacl_test.keys.boxSk);
-	ok(ct, 'Ciphertext length: ' + ct.length);
+	var ct = nacl_test.crypto.asymmetricEncrypt(plaintext, nacl_test.recipientKeypair.boxPk, nacl_test.senderKeypair.boxSk);
+	ok(ct.ct && ct.nonce, 'Ciphertext length: ' + ct.ct.length);
 
 	// decrypt
-	var decryptedBuf = nacl.crypto_secretbox_open(ct, nonce, nacl_test.keys.boxSk);
-	var decrypted = nacl.decode_utf8(decryptedBuf);
+	var decrypted = nacl_test.crypto.asymmetricDecrypt(ct.ct, ct.nonce, nacl_test.senderKeypair.boxPk, nacl_test.recipientKeypair.boxSk);
 	equal(decrypted, plaintext, 'Decryption correct: ' + decrypted);
-
 });
\ No newline at end of file