From 4b23ef74d7fc9f5273295ee539bc0dddf132e595 Mon Sep 17 00:00:00 2001
From: ansuz <ansuz@transitiontech.ca>
Date: Thu, 6 Jul 2017 18:30:16 +0200
Subject: [PATCH] add support for curve message signing and curve validateKeys

---
 www/common/curve-put.js | 10 ++++--
 www/common/curve.js     | 80 ++++++++++++++++++++++++++++++++---------
 www/invite/main.js      |  5 ++-
 3 files changed, 73 insertions(+), 22 deletions(-)

diff --git a/www/common/curve-put.js b/www/common/curve-put.js
index a57e7ac5e..450b62564 100644
--- a/www/common/curve-put.js
+++ b/www/common/curve-put.js
@@ -4,15 +4,19 @@ define([
 ], function (Curve, Listmap) {
     var Edit = {};
 
-    Edit.create = function (network, channel, theirs, mine, cb) {
+    Edit.create = function (config, cb) { //network, channel, theirs, mine, cb) {
+        var network = config.network;
+        var channel = config.channel;
+        var keys = config.keys;
+
         try {
-            var encryptor = Curve.createEncryptor(theirs, mine);
+            var encryptor = Curve.createEncryptor(keys);
             var lm = Listmap.create({
                 network: network,
                 data: {},
                 channel: channel,
                 readOnly: false,
-                validateKey: undefined,
+                validateKey: keys.validateKey || undefined,
                 crypto: encryptor,
                 userName: 'lol',
                 logLevel: 1,
diff --git a/www/common/curve.js b/www/common/curve.js
index f0707662e..b33823fd5 100644
--- a/www/common/curve.js
+++ b/www/common/curve.js
@@ -4,32 +4,80 @@ define([
     var Nacl = window.nacl;
     var Curve = {};
 
-    // nacl.box(message, nonce, theirPublicKey, mySecretKey)
-    Curve.encrypt = function (message, theirPub, mySecret) {
-        var buffer = Nacl.util.decodeUTF8(message);
+    var concatenateUint8s = function (A) {
+        var len = 0;
+        var offset = 0;
+        A.forEach(function (uints) {
+            len += uints.length || 0;
+        });
+        var c = new Uint8Array(len);
+        A.forEach(function (x) {
+            c.set(x, offset);
+            offset += x.length;
+        });
+        return c;
+    };
+
+    var encodeBase64 = Nacl.util.encodeBase64;
+    var decodeBase64 = Nacl.util.decodeBase64;
+    var decodeUTF8 = Nacl.util.decodeUTF8;
+    var encodeUTF8 = Nacl.util.encodeUTF8;
+
+    Curve.encrypt = function (message, secret) {
+        var buffer = decodeUTF8(message);
         var nonce = Nacl.randomBytes(24);
-        var box = Nacl.box(buffer, nonce, theirPub, mySecret);
-        return Nacl.util.encodeBase64(nonce) + '|' + Nacl.util.encodeBase64(box);
+        var box = Nacl.box.after(buffer, nonce, secret);
+        return encodeBase64(nonce) + '|' + encodeBase64(box);
     };
 
-    // nacl.box.open(box, nonce, theirPublicKey, mySecretKey)
-    Curve.decrypt = function (packed, theirPub, mySecret) {
+    Curve.decrypt = function (packed, secret) {
         var unpacked = packed.split('|');
-        var nonce = Nacl.util.decodeBase64(unpacked[0]);
-        var box = Nacl.util.decodeBase64(unpacked[1]);
-        var message = Nacl.box.open(box, nonce, theirPub, mySecret);
-        return Nacl.util.encodeUTF8(message);
+        var nonce = decodeBase64(unpacked[0]);
+        var box = decodeBase64(unpacked[1]);
+        var message = Nacl.box.open.after(box, nonce, secret);
+        return encodeUTF8(message);
+    };
+
+    Curve.signAndEncrypt = function (msg, cryptKey, signKey) {
+        var packed = Curve.encrypt(msg, cryptKey);
+        return encodeBase64(Nacl.sign(decodeUTF8(packed), signKey));
+    };
+
+    Curve.openSigned = function (msg, cryptKey /*, validateKey STUBBED*/) {
+        var content = decodeBase64(msg).subarray(64);
+        return Curve.decrypt(encodeUTF8(content), cryptKey);
     };
 
-    Curve.createEncryptor = function (theirPublic, mySecret) {
-        var theirs = Nacl.util.decodeBase64(theirPublic);
-        var mine = Nacl.util.decodeBase64(mySecret);
+    Curve.deriveKeys = function (theirs, mine) {
+        var pub = decodeBase64(theirs);
+        var secret = decodeBase64(mine);
+
+        var sharedSecret = Nacl.box.before(pub, secret);
+        var salt = decodeUTF8('CryptPad.signingKeyGenerationSalt');
+
+        // 64 uint8s
+        var hash = Nacl.hash(concatenateUint8s([salt, sharedSecret]));
+        var signKp = Nacl.sign.keyPair.fromSeed(hash.subarray(0, 32));
+        var cryptKey = hash.subarray(32, 64);
+
+        return {
+            cryptKey: encodeBase64(cryptKey),
+            signKey: encodeBase64(signKp.secretKey),
+            validateKey: encodeBase64(signKp.publicKey)
+        };
+    };
+
+    Curve.createEncryptor = function (keys) {
+        var cryptKey = decodeBase64(keys.cryptKey);
+        var signKey = decodeBase64(keys.signKey);
+        var validateKey = decodeBase64(keys.validateKey);
+
         return {
             encrypt: function (msg) {
-                return Curve.encrypt(msg, theirs, mine);
+                return Curve.signAndEncrypt(msg, cryptKey, signKey);
             },
             decrypt: function (packed) {
-                return Curve.decrypt(packed, theirs, mine);
+                return Curve.openSigned(packed, cryptKey, validateKey);
             }
         };
     };
diff --git a/www/invite/main.js b/www/invite/main.js
index df58db885..09154c82d 100644
--- a/www/invite/main.js
+++ b/www/invite/main.js
@@ -28,11 +28,10 @@ define([
         var proxy = Cryptpad.getProxy();
         var mySecret = proxy.curvePrivate;
 
-        var encryptor = Curve.createEncryptor(info.pubkey, mySecret);
+        var keys = Curve.deriveKeys(info.pubkey, mySecret);
+        var encryptor = Curve.createEncryptor(keys);
 
         Cryptpad.removeLoadingScreen();
-        var message = 'hello!';
-        Cryptpad.alert(message);
 
         var listmapConfig = {
             data: {},