Index: build/chrome/cackey.js
==================================================================
--- build/chrome/cackey.js
+++ build/chrome/cackey.js
@@ -325,10 +325,13 @@
 			digestHeader = new Uint8Array([0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14]);
 			break;
 		case "SHA-256":
 			digestHeader = new Uint8Array([0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20]);
 			break;
+		case "MD5_SHA1":
+			digestHeader = new Uint8Array();
+			break;
 		default:
 			console.error("[cackey] Asked to sign a message with a hash we do not support: " + signRequest.hash);
 
 			chromeCallback();