ES6: Migrated "assets" (#912)

.eslintrc.yaml

@@ -7,9 +7,12 @@ extends:
   "eslint:recommended"
 
 globals:
+  _: true
   $: true
   amplify: true
   ko: true
+  LRUCache: true
+  wire: true
   z: true
 
 rules:

app/script/assets/Asset.js

@@ -0,0 +1,65 @@
+/*
+ * Wire
+ * Copyright (C) 2016 Wire Swiss GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see http://www.gnu.org/licenses/.
+ *
+ */
+
+'use strict';
+
+window.z = window.z || {};
+window.z.assets = z.assets || {};
+
+z.assets.Asset = class Asset {
+
+  /*
+  Construct a new asset for the asset service.
+
+  @deprecated
+  @param {Object} config - Asset configuration
+  */
+  constructor(config) {
+    this.correlation_id = config.correlation_id || z.util.create_random_uuid();
+    this.content_type = config.content_type;
+    this.array_buffer = config.array_buffer;
+    this.payload = {
+      conv_id: config.conversation_id,
+      correlation_id: this.correlation_id,
+      public: config.public || false,
+      tag: config.tag || 'medium',
+      inline: config.inline || false,
+      nonce: this.correlation_id,
+      md5: config.md5,
+      width: config.width,
+      height: config.height,
+      original_width: config.original_width || config.width,
+      original_height: config.original_height || config.width,
+      native_push: config.native_push || false,
+    };
+  }
+
+  /*
+  Create the content disposition header for the asset.
+  */
+  get_content_disposition() {
+    const payload = ['zasset'];
+    for (let key in this.payload) {
+      const value = this.payload[key];
+      payload.push(`${key}=${value}`);
+    }
+    return payload.join(';');
+  }
+
+};

app/script/assets/AssetCrypto.js

@@ -0,0 +1,81 @@
+/*
+ * Wire
+ * Copyright (C) 2016 Wire Swiss GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see http://www.gnu.org/licenses/.
+ *
+ */
+
+'use strict';
+
+window.z = window.z || {};
+window.z.assets = z.assets || {};
+
+z.assets.AssetCrypto = {
+
+  /*
+  @param {ArrayBuffer} key_bytes - AES key used for encryption
+  @param {ArrayBuffer} computed_sha256 - SHA-256 checksum of the ciphertext
+  @param {ArrayBuffer} ciphertext - Encrypted plaintext
+  */
+  encrypt_aes_asset(plaintext) {
+    const iv = new Uint8Array(16);
+    let key = null;
+    let iv_ciphertext = null;
+    let computed_sha256 = null;
+
+    window.crypto.getRandomValues(iv);
+
+    return window.crypto.subtle.generateKey({name: 'AES-CBC', length: 256}, true, ['encrypt'])
+    .then(function(ckey) {
+      key = ckey;
+
+      return window.crypto.subtle.encrypt({name: 'AES-CBC', iv: iv.buffer}, key, plaintext);
+    }).then(function(ciphertext) {
+      iv_ciphertext = new Uint8Array(ciphertext.byteLength + iv.byteLength);
+      iv_ciphertext.set(iv, 0);
+      iv_ciphertext.set(new Uint8Array(ciphertext), iv.byteLength);
+
+      return window.crypto.subtle.digest('SHA-256', iv_ciphertext);
+    }).then(function(digest) {
+      computed_sha256 = digest;
+
+      return window.crypto.subtle.exportKey('raw', key);
+    }).then(key_bytes => [key_bytes, computed_sha256, iv_ciphertext.buffer]);
+  },
+
+  /*
+  @param {ArrayBuffer} key_bytes - AES key used for encryption
+  @param {ArrayBuffer} computed_sha256 - SHA-256 checksum of the ciphertext
+  @param {ArrayBuffer} ciphertext - Encrypted plaintext
+  */
+  decrypt_aes_asset(ciphertext, key_bytes, reference_sha256) {
+    return window.crypto.subtle.digest('SHA-256', ciphertext)
+    .then(function(computed_sha256) {
+      const a = new Uint32Array(reference_sha256);
+      const b = new Uint32Array(computed_sha256);
+
+      if ((a.length === b.length) && a.every((x, i) => x === b[i])) {
+        return window.crypto.subtle.importKey('raw', key_bytes, 'AES-CBC', false, ['decrypt']);
+      }
+
+      throw new Error('Encrypted asset does not match its SHA-256 hash');
+    }).then(function(key) {
+      const iv = ciphertext.slice(0, 16);
+      const img_ciphertext = ciphertext.slice(16);
+      return window.crypto.subtle.decrypt({name: 'AES-CBC', iv}, key, img_ciphertext);
+    });
+  },
+
+};