use channel encryption with storage server

js/modules/loki_message_api.js

@@ -1,11 +1,13 @@
 /* eslint-disable no-await-in-loop */
 /* eslint-disable no-loop-func */
-/* global log, dcodeIO, window, callWorker, lokiP2pAPI, lokiSnodeAPI */
+/* global log, dcodeIO, window, callWorker, lokiP2pAPI, lokiSnodeAPI, libloki */
 
 const nodeFetch = require('node-fetch');
 const _ = require('lodash');
+const { parse } = require('url');
 
 const endpointBase = '/v1/storage_rpc';
+const LOKI_EPHEMKEY_HEADER = 'X-Loki-EphemKey';
 
 class HTTPError extends Error {
   constructor(response) {
@@ -27,6 +29,25 @@ const fetch = async (url, options = {}) => {
   const timeout = options.timeout || 10000;
   const method = options.method || 'GET';
 
+  const address = parse(url).hostname;
+  const doEncryptChannel =
+    address.endsWith('.snode') &&
+    options.headers &&
+    LOKI_EPHEMKEY_HEADER in options.headers;
+  if (doEncryptChannel) {
+    try {
+      // eslint-disable-next-line no-param-reassign
+      options.body = await libloki.crypto.snodeCipher.encrypt(
+        address,
+        options.body
+      );
+      // eslint-disable-next-line no-param-reassign
+      options.headers['Content-Type'] = 'text/plain';
+    } catch (e) {
+      log.warn(`Could not encrypt channel for ${address}: `, e);
+    }
+  }
+
   try {
     const response = await nodeFetch(url, {
       ...options,
@@ -45,6 +66,18 @@ const fetch = async (url, options = {}) => {
       result = await response.buffer();
     } else {
       result = await response.text();
+      if (doEncryptChannel) {
+        try {
+          result = await libloki.crypto.snodeCipher.decrypt(address, result);
+        } catch (e) {
+          log.warn(`Could not decrypt response from ${address}`, e);
+        }
+        try {
+          result = JSON.parse(result);
+        } catch(e) {
+          log.warn(`Could not parse string to json ${result}`, e);
+        }
+      }
     }
 
     return result;
@@ -151,7 +184,7 @@ class LokiMessageAPI {
         method: 'POST',
         body: JSON.stringify(body),
         headers: {
-          'X-Loki-EphemKey': 'not implemented yet',
+          [LOKI_EPHEMKEY_HEADER]: libloki.crypto.snodeCipher.getChannelPublicKeyHex(),
         },
       };
 
@@ -247,7 +280,7 @@ class LokiMessageAPI {
         },
       };
       const headers = {
-        'X-Loki-EphemKey': 'not implemented yet',
+        [LOKI_EPHEMKEY_HEADER]: libloki.crypto.snodeCipher.getChannelPublicKeyHex(),
       };
       const fetchOptions = {
         method: 'POST',

libloki/crypto.js

@@ -1,4 +1,13 @@
-/* global window, libsignal, textsecure, StringView, Multibase */
+/* global
+  window,
+  libsignal,
+  textsecure,
+  StringView,
+  Multibase,
+  TextEncoder,
+  TextDecoder,
+  dcodeIO
+*/
 
 // eslint-disable-next-line func-names
 (function() {
@@ -81,7 +90,7 @@
     return ab;
   }
 
-  function decodeSnodeAddressToBuffer(snodeAddress) {
+  function decodeSnodeAddressToPubKey(snodeAddress) {
     const snodeAddressClean = snodeAddress
       .replace('.snode', '')
       .replace('http://', '');
@@ -99,12 +108,16 @@
       this._cache = {};
     }
 
-    _getSymmetricKey(snodeAddress) {
+    async _getSymmetricKey(snodeAddress) {
       if (snodeAddress in this._cache) {
         return this._cache[snodeAddress];
       }
-      const buffer = decodeSnodeAddressToBuffer(snodeAddress);
-      const snodePubKeyArrayBuffer = bufferToArrayBuffer(buffer);
+      const ed25519PubKey = decodeSnodeAddressToPubKey(snodeAddress);
+      const sodium = await window.getSodium();
+      const curve25519PubKey = sodium.crypto_sign_ed25519_pk_to_curve25519(
+        ed25519PubKey
+      );
+      const snodePubKeyArrayBuffer = bufferToArrayBuffer(curve25519PubKey);
       const symmetricKey = libsignal.Curve.calculateAgreement(
         snodePubKeyArrayBuffer,
         this._ephemeralKeyPair.privKey
@@ -117,18 +130,30 @@
       return this._ephemeralPubKeyHex;
     }
 
-    async decrypt(snodeAddress, ivAndCipherText) {
-      const symmetricKey = this._getSymmetricKey(snodeAddress);
+    async decrypt(snodeAddress, ivAndCipherTextBase64) {
+      const ivAndCipherText = dcodeIO.ByteBuffer.wrap(
+        ivAndCipherTextBase64,
+        'base64'
+      ).toArrayBuffer();
+      const symmetricKey = await this._getSymmetricKey(snodeAddress);
       try {
-        return await DHDecrypt(symmetricKey, ivAndCipherText);
+        const decrypted = await DHDecrypt(symmetricKey, ivAndCipherText);
+        const decoder = new TextDecoder();
+        return decoder.decode(decrypted);
       } catch (e) {
         return ivAndCipherText;
       }
     }
 
     async encrypt(snodeAddress, plainText) {
-      const symmetricKey = this._getSymmetricKey(snodeAddress);
-      return DHEncrypt(symmetricKey, plainText);
+      if (typeof plainText === 'string') {
+        const textEncoder = new TextEncoder();
+        // eslint-disable-next-line no-param-reassign
+        plainText = textEncoder.encode(plainText);
+      }
+      const symmetricKey = await this._getSymmetricKey(snodeAddress);
+      const cipherText = await DHEncrypt(symmetricKey, plainText);
+      return dcodeIO.ByteBuffer.wrap(cipherText).toString('base64');
     }
   }
 
@@ -142,6 +167,6 @@
     snodeCipher,
     // for testing
     _LokiSnodeChannel: LokiSnodeChannel,
-    _decodeSnodeAddressToBuffer: decodeSnodeAddressToBuffer,
+    _decodeSnodeAddressToPubKey: decodeSnodeAddressToPubKey,
   };
 })();

package.json

@@ -77,6 +77,7 @@
     "jquery": "3.3.1",
     "js-sha512": "0.8.0",
     "jsbn": "1.1.0",
+    "libsodium-wrappers": "^0.7.4",
     "linkify-it": "2.0.3",
     "lodash": "4.17.11",
     "mkdirp": "0.5.1",

preload.js

@@ -339,6 +339,13 @@ window.React = require('react');
 window.ReactDOM = require('react-dom');
 window.moment = require('moment');
 
+const _sodium = require('libsodium-wrappers');
+
+window.getSodium = async () => {
+  await _sodium.ready;
+  return _sodium;
+};
+
 window.clipboard = clipboard;
 
 const Signal = require('./js/modules/signal');