Log encryption failures

https://bugzilla.redhat.com/show_bug.cgi?id=1518058

Customers might export/import models between different environments.
There typically is a different key for each environment. If the export
deck has encrypted fields, they are imported into the new environment
unchanged. This field cannot be decrypted at runtime in the Automate
engine, because of key mismatch.
During $evm.instantiate we were not logging any error messages and
customer has a tough time debugging the issue.

This PR logs the encryption error.

lib/miq_automation_engine/engine/miq_ae_engine/miq_ae_object.rb

@@ -545,7 +545,7 @@ def self.convert_value_based_on_datatype(value, datatype)
       return value.to_i                                      if datatype == 'integer' || datatype == 'Fixnum'
       return value.to_f                                      if datatype == 'float' || datatype == 'Float'
       return value.gsub(/[\[\]]/, '').strip.split(/\s*,\s*/)  if datatype == 'array' && value.class == String
-      return MiqAePassword.new(MiqAePassword.decrypt(value)) if datatype == 'password'
+      return decrypt_password(value) if datatype == 'password'
 
       if datatype &&
          (service_model = "MiqAeMethodService::MiqAeService#{SM_LOOKUP[datatype]}".safe_constantize)
@@ -558,6 +558,14 @@ def self.convert_value_based_on_datatype(value, datatype)
       value
     end
 
+    def self.decrypt_password(value)
+      MiqAePassword.new(MiqAePassword.decrypt(value))
+    rescue MiqPassword::MiqPasswordError => err
+      $miq_ae_logger.error("Error decrypting password #{err.message}. Is this password imported from a different environment?")
+      raise err
+    end
+    private_class_method :decrypt_password
+
     def process_assertion(f, message, args)
       Benchmark.current_realtime[:assertion_count] += 1
       Benchmark.realtime_block(:assertion_time) do

lib/miq_automation_engine/engine/miq_ae_method_service/miq_ae_service.rb

@@ -91,6 +91,7 @@ def instantiate(uri)
       return nil if obj.nil?
       MiqAeServiceObject.new(obj, self)
     rescue => e
+      $miq_ae_logger.error("instantiate failed : #{e.message}")
       return nil
     end
 

spec/miq_ae_object_spec.rb

@@ -300,3 +300,20 @@ def value_match(value, xml_value)
     end
   end
 end
+
+describe MiqAeEngine::MiqAeObject do
+  context "password" do
+    let(:p45) { "Pneumonoultramicroscopicsilicovolcanoconiosis" }
+    let(:p45_encrypted) { MiqAePassword.encrypt(p45) }
+
+    it "can decrypt passwords" do
+      expect(described_class.convert_value_based_on_datatype(p45_encrypted, 'password').encStr).to eq(p45_encrypted)
+    end
+
+    it "raises exception for bogus passwords" do
+      expect do
+        described_class.convert_value_based_on_datatype('gobbledygook', 'password')
+      end.to raise_exception(MiqPassword::MiqPasswordError)
+    end
+  end
+end