producer: Add error callback

Change-Id: I2cca1c8d06da2de20fdde09e1513d2fcb3f5df5f
Refs: #3355
diff --git a/src/error-code.hpp b/src/error-code.hpp
index 3e5d2a6..d1908f1 100644
--- a/src/error-code.hpp
+++ b/src/error-code.hpp
@@ -32,7 +32,8 @@
   Validation = 2,
   UnsupportedEncryptionScheme = 32,
   InvalidEncryptedFormat = 33,
-  NoDecryptKey = 34
+  NoDecryptKey = 34,
+  EncryptionFailure = 35
 };
 
 typedef function<void (const ErrorCode&, const std::string&)> ErrorCallBack;