Merge pull request #20 from paritytech/kirushik/more_compact_encoding

Use base64 for shards encoding; print versions and commit hashes everywhere

Author: Kirill Pimenov

.circleci/config.yml

@@ -2,7 +2,7 @@ version: 2
 jobs:
   build:
     docker:
-      - image: circleci/node:10
+      - image: circleci/node:12
     working_directory: ~/repo
     steps:
       - checkout

package.json

@@ -5,10 +5,8 @@
   "contributors": [
     "Kirill Pimenov <[email protected]>"
   ],
-
-  "version": "0.1.0",
+  "version": "0.2.0",
   "private": true,
-
   "scripts": {
     "serve": "vue-cli-service serve",
     "build": "vue-cli-service build",
@@ -17,6 +15,7 @@
     "test:unit": "vue-cli-service test:unit"
   },
   "dependencies": {
+    "base64-js": "^1.3.0",
     "scryptsy": "^2.0.0",
     "secrets.js-grempe": "^1.1.0",
     "tweetnacl": "^1.0.0",

src/App.vue

@@ -11,6 +11,7 @@
     </div>
     <SavePageInfo v-else-if="!localFile"/>
     <GoOfflineInfo v-else-if="isOnline"/>
+    <p class="version-footer">BananaSplit version {{version}}, git revision {{gitRevision}}</p>
   </div>
 </template>
 
@@ -20,19 +21,27 @@ import GoOfflineInfo from './components/GoOfflineInfo'
 import SavePageInfo from './components/SavePageInfo'
 import ForkMe from './components/ForkMe'
 
+import {version} from '../package.json';
+
 export default {
   name: 'App',
   components: {GeneralInfo, GoOfflineInfo, SavePageInfo, ForkMe},
   computed: {
     localFile: function() {
-      return (window.location.protocol === 'file:');
+      return (window.location.protocol === 'file:')
     },
     secure: function() {
       if (process.env.NODE_ENV === 'production') {
         return this.localFile && !this.isOnline;
       } else {
         return true
       }
+    },
+    version: function() {
+      return version
+    },
+    gitRevision: function() {
+      return process.env.GIT_REVISION;
     }
   }
 }
@@ -67,4 +76,10 @@ nav a.router-link-exact-active {
      display: none;
   }
 }
+
+.version-footer {
+  font-size: 80%;
+  font-style: italic;
+  color: darkgray;
+}
 </style>

src/components/ShardQrCode.vue

@@ -5,18 +5,20 @@
             <h3>You need {{requiredShards - 1}} more QR {{pluralizeCode}} like this to reconstruct the secret</h3>
             <h4>Please go to <a href="https://bs.parity.io">https://bs.parity.io</a> to download the reconstruction webapp, if you don't have one already</h4>
         </div>
-        <qriously class="print-only" v-bind:value="shard" v-bind:size="600" />
+        <qriously class="print-only" v-bind:value="shard" v-bind:size="750" />
         <qriously class="screen-only" v-bind:value="shard" v-bind:size="200" />
         <div class="print-only">
             <div class="recovery-field">
                 <div class="recovery-title">Recovery&nbsp;passphrase&nbsp;is&nbsp;</div>
                 <div class="recovery-blank"/>
             </div>
+            <p class="version">This has been generated by BananaSplit version {{version}}, git revision {{gitRevision}}</p>
         </div>
     </div>
 </template>
 
 <script>
+import {version} from '../../package.json';
 export default {
     name: 'ShardQrCode',
     props: {
@@ -31,6 +33,12 @@ export default {
             } else {
                 return 'codes'
             }
+        },
+        version: function() {
+            return version;
+        },
+        gitRevision: function() {
+            return process.env.GIT_REVISION;
         }
     }
 }
@@ -66,4 +74,9 @@ export default {
     width: 100%;
     border-bottom: 1px solid black;
 }
+
+.version {
+    font-style: italic;
+    color: darkgray;
+}
 </style>

src/util/crypto.js

@@ -1,3 +1,4 @@
+const BASE64 = require("base64-js");
 const CRYPTO = require("tweetnacl");
 const SCRYPT = require("scryptsy");
 
@@ -55,13 +56,17 @@ function decrypt(data, salt, passphrase, nonce) {
 function share(data, title, passphrase, totalShards, requiredShards) {
     var salt = hashString(title);
     var encrypted = encrypt(data, salt, passphrase);
-    var nonce = hexify(encrypted.nonce);
+    var nonce = BASE64.fromByteArray(encrypted.nonce);
     var hexEncrypted = hexify(encrypted.value);
     return SECRETS.share(hexEncrypted, totalShards, requiredShards).map(function (shard) {
+        // First char is non-hex (base36) and signifies the bitfield size of our share
+        var encodedShard = shard[0] + BASE64.fromByteArray(dehexify(shard.slice(1)));
+
         return JSON.stringify({
+            v: 1,
             t: title,
             r: requiredShards,
-            d: shard,
+            d: encodedShard,
             n: nonce
         }).replace(/[\u007F-\uFFFF]/g, function (chr) {
             return "\\u" + ("0000" + chr.charCodeAt(0).toString(16)).substr(-4)
@@ -72,6 +77,7 @@ function share(data, title, passphrase, totalShards, requiredShards) {
 function parse(payload) {
     let parsed = JSON.parse(payload);
     return {
+        version: parsed.v || 0, // 'undefined' version is treated as 0
         title: parsed.t,
         requiredShards: parsed.r,
         data: parsed.d,
@@ -80,8 +86,6 @@ function parse(payload) {
 }
 
 function reconstruct(shardObjects, passphrase) {
-    var shardData = shardObjects.map(shard => shard.data);
-
     var shardsRequirements = shardObjects.map(shard => shard.requiredShards);
     if (!shardsRequirements.every(r => r===shardsRequirements[0])) {
         throw "Mismatching min shards requirement among shards!"
@@ -100,11 +104,31 @@ function reconstruct(shardObjects, passphrase) {
         throw "Titles mismatch among shards!"
     }
 
-    var encryptedSecret = SECRETS.combine(shardData);
-    var secret = dehexify(encryptedSecret);
-    var nonce = dehexify(nonces[0]);
-    var salt = hashString(titles[0]);
-    return uint8ArrayToStr(decrypt(secret, salt, passphrase, nonce));
+    var versions = shardObjects.map(shard => shard.version);
+    if  (!versions.every(v => v===versions[0])) {
+        throw "Versions mismatch along shards!"
+    }
+
+    switch (versions[0]) {
+        case 0:
+            var shardData = shardObjects.map(shard => shard.data);
+            var encryptedSecret = SECRETS.combine(shardData);
+            var secret = dehexify(encryptedSecret);
+            var nonce = dehexify(nonces[0]);
+            var salt = hashString(titles[0]);
+            return uint8ArrayToStr(decrypt(secret, salt, passphrase, nonce));
+
+        case 1:
+            var shardDataV1 = shardObjects.map(shard => shard.data[0]+hexify(BASE64.toByteArray(shard.data.slice(1))));
+            var encryptedSecretV1 = SECRETS.combine(shardDataV1);
+            var secretV1 = dehexify(encryptedSecretV1);
+            var nonceV1 = BASE64.toByteArray(nonces[0]);
+            var saltV1 = hashString(titles[0]);
+            return uint8ArrayToStr(decrypt(secretV1, saltV1, passphrase, nonceV1));
+
+        default:
+            throw "Version is not supported!";
+    }
 }
 
 export default {

src/views/Share.vue

@@ -3,10 +3,11 @@
     <div id="share-controls">
         <h1>Share secrets</h1>
         <p>What is this thing? <input type="text" :disabled="encryptionMode" v-model="title" placeholder="Like, 'Bitcoin seed phrase'" autofocus/></p>
-        <textarea v-model="secret" :disabled="encryptionMode" placeholder="Your secret goes here"></textarea>
+        <textarea v-model="secret" v-bind:class="{tooLong: secretTooLong}" :disabled="encryptionMode" placeholder="Your secret goes here"></textarea>
+        <div v-if="this.secretTooLong">Inputs longer than 1024 characters make QR codes illegible</div>
         <p>Will require any {{requiredShards}} shards out of <input type="number" v-model.number="totalShards" min="3" />
             to reconstruct</p>
-        <button v-on:click="toggleMode">
+        <button :disabled="secretTooLong" v-on:click="toggleMode">
             <span v-if="this.encryptionMode">Back to editing data</span>
             <span v-else>Generate QR codes!</span>
         </button>
@@ -42,11 +43,14 @@ export default {
             secret: '',
             totalShards: 3, // TODO: 5
             recoveryPassphrase: bipPhrase.generate(4),
-            encryptionMode: false,
+            encryptionMode: false
         }
     },
     components: { ShardInfo, CanvasText },
     computed: {
+        secretTooLong: function() {
+            return this.secret.length > 1024;
+        },
         requiredShards: function () {
             return Math.floor(this.totalShards / 2) + 1;
         },
@@ -75,6 +79,10 @@ export default {
 </script>
 
 <style>
+textarea.tooLong {
+    border: 5px solid red;
+}
+
 #qr-tiles {
     display: flex;
     flex-wrap: wrap;

tests/unit/crypto.spec.js

@@ -65,6 +65,21 @@ test('reconstructs the reference example of v0 serialization', () => {
     });
 })
 
+test('reconstructs the reference example of v1 serialization', () => {
+    var shards = [
+        '{"v":1,"t":"Pssst","r":2,"d":"8AdI3F1Xn4CK9mXEVWLWgg2gzho5WV38E/hn1OYyRMZenL/Jm6dmrZoiji2ZlMSVEW+XN9WW1I/ilDC1yiu4oBa4=","n":"a17TDZHP2iL/sdPHgFJUP3NlAC7bDgrp"}',
+        '{"v":1,"t":"Pssst","r":2,"d":"8ArluLqrT3URnL+IqsHddG9MpXqvSNt5JBLfTqSJmCg4raIFLg2XhfbnFLCTgCumI4qByThq9bBxnwLy8EgEHYiw=","n":"a17TDZHP2iL/sdPHgFJUP3NlAC7bDgrp"}',
+        '{"v":1,"t":"Pssst","r":2,"d":"8A2tZOf80PWbatpM/6ML9mLrUFkOu4kpyUiY62bPA6HmkVVtQpfosdF3nuhpo6K3MfmjsJ8ROokDShDgNka/ptFI=","n":"a17TDZHP2iL/sdPHgFJUP3NlAC7bDgrp"}'
+    ].map(s => crypto.parse(s));
+
+    [
+        [0, 1], [0, 2], [1, 2],
+        [1, 0], [2, 0], [2, 1]
+    ].forEach(([i,j]) => {
+        expect(crypto.reconstruct([shards[i], shards[j]], 'excess-torch-unfold-fix')).toBe('Version one is all-around better')
+    });
+})
+
 test('throws an error if nonces mismatch', () => {
     var shards = crypto.share('Message', 'Title', 'correct-horse-battery-staple', 3, 2).map(s => crypto.parse(s));
     shards[0].nonce = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"

vue.config.js

@@ -1,5 +1,9 @@
 let HtmlWebpackPlugin = require('html-webpack-plugin');
 let HtmlWebpackInlineSourcePlugin = require('html-webpack-inline-source-plugin');
+let Webpack = require('webpack');
+
+let childProcess = require('child_process');
+let GIT_REVISION = childProcess.execSync('git rev-parse HEAD').toString();
 
 module.exports = {
   productionSourceMap: false,
@@ -12,7 +16,12 @@ module.exports = {
         template: 'public/index.html',
         inlineSource: '.(js|css)$'
       }),
-      new HtmlWebpackInlineSourcePlugin(HtmlWebpackPlugin)
+      new HtmlWebpackInlineSourcePlugin(HtmlWebpackPlugin),
+      new Webpack.DefinePlugin({
+        'process.env': {
+          'GIT_REVISION': JSON.stringify(GIT_REVISION)
+        }
+      })
     ]
   }
 }