diff -r 000000000000 -r 6474c204b198 services/crypto/tests/unit/test_crypto_deriveKey.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/services/crypto/tests/unit/test_crypto_deriveKey.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,38 @@
+var btoa;
+
+function test_derive(cryptoSvc) {
+  // Extracted from test_utils_deriveKey.
+  let pp = "secret phrase";
+  let salt = "RE5YUHpQcGl3bg==";   // btoa("DNXPzPpiwn")
+  
+  // 16-byte, extract key data.
+  let k = cryptoSvc.deriveKeyFromPassphrase(pp, salt, 16);
+  do_check_eq(16, k.length);
+  do_check_eq(btoa(k), "d2zG0d2cBfXnRwMUGyMwyg==");
+  
+  // Test different key lengths.
+  k = cryptoSvc.deriveKeyFromPassphrase(pp, salt, 32);
+  do_check_eq(32, k.length);
+  let encKey = btoa(k);
+  
+  // Test via encryption.
+  let iv = cryptoSvc.generateRandomIV();
+  do_check_eq(cryptoSvc.decrypt(cryptoSvc.encrypt("bacon", encKey, iv), encKey, iv), "bacon");
+  
+  // Test default length (32).
+  k = cryptoSvc.deriveKeyFromPassphrase(pp, salt, null);
+  do_check_eq(32, k.length);
+  do_check_eq(encKey, btoa(k));
+}
+
+function run_test() {
+  let cryptoSvc;
+  try {
+    let backstagePass = Components.utils.import("resource://services-crypto/WeaveCrypto.js");
+    btoa = backstagePass.btoa;
+  } catch (ex) {
+    _("Aborting test: no WeaveCrypto.js.");
+    return;
+  }
+  test_derive(new WeaveCrypto());
+}