Bug 1520949 - Use TextEncoder/TextDecoder to handle multibyte characters in passwords. r=MattN

Differential Revision: https://phabricator.services.mozilla.com/D20625

--HG--
extra : moz-landing-system : lando

browser/components/migration/tests/unit/test_Chrome_passwords.js

@@ -50,7 +50,7 @@ const TEST_LOGINS = [
   {
     id: 4,
     username: "user",
-    password: "password",
+    password: "اقرأPÀßwörd",
     hostname: "http://httpbin.org",
     formSubmitURL: null,
     httpRealm: "me@kennethreitz.com", // Digest auth.

toolkit/components/passwordmgr/OSCrypto_win.js

@@ -174,9 +174,8 @@ OSCrypto.prototype = {
     let len = outData.cbData;
     let decrypted = ctypes.cast(outData.pbData,
                                 wintypes.BYTE.array(len).ptr).contents;
-    for (let i = 0; i < decrypted.length; i++) {
-      decryptedData += String.fromCharCode(decrypted[i]);
-    }
+    // Output that may include characters outside of the 0-255 (byte) range needs to use TextDecoder.
+    decryptedData = (new TextDecoder()).decode(new Uint8Array(decrypted));
 
     this._functions.get("LocalFree")(outData.pbData);
     return decryptedData;
@@ -191,9 +190,11 @@ OSCrypto.prototype = {
    */
   encryptData(data, entropy = null) {
     let encryptedData = "";
-    let decryptedData = wintypes.BYTE.array(data.length)(this.stringToArray(data));
+    // Input that may include characters outside of the 0-255 (byte) range needs to use TextEncoder.
+    let decryptedByteData = [...(new TextEncoder()).encode(data)];
+    let decryptedData = wintypes.BYTE.array(decryptedByteData.length)(decryptedByteData);
 
-    let inData = new this._structs.DATA_BLOB(data.length, decryptedData);
+    let inData = new this._structs.DATA_BLOB(decryptedData.length, decryptedData);
     let outData = new this._structs.DATA_BLOB();
     let entropyParam;
     if (!entropy) {

toolkit/components/passwordmgr/test/unit/test_OSCrypto_win.js

@@ -54,6 +54,9 @@ add_task(function test_decryptData_encryptData() {
                                                        key),
                                     key),
                  "https://bugzilla.mozilla.org/page.cgi");
+
+    Assert.equal(crypto.decryptData(crypto.encryptData("新年快樂新年快樂", key), key),
+                 "新年快樂新年快樂");
   }
 
   let keys = [null, "a", "keys", "abcdedf", "pass", "https://bugzilla.mozilla.org/page.cgi",