Add ECDSA signing and verification.

Change-Id: Ic5345ebe6e79e3ee764c3a729dc551c61b87c79b
diff --git a/google_keymaster.cpp b/google_keymaster.cpp
index d4bc7a8..6e9d5cf 100644
--- a/google_keymaster.cpp
+++ b/google_keymaster.cpp
@@ -238,6 +238,9 @@
     case KM_ALGORITHM_DSA:
         operation.reset(new DsaOperation(request.purpose, *key));
         break;
+    case KM_ALGORITHM_ECDSA:
+        operation.reset(new EcdsaOperation(request.purpose, *key));
+        break;
     default:
         response->error = KM_ERROR_UNSUPPORTED_ALGORITHM;
         break;