Arcitura Education S90.20 Exam - Topic 1 Question 10 Discussion

Question

Service A provides a data retrieval capability that can be used by a range of service consumers, including Service Consumer A .In order to retrieve the necessary data, Service Consumer A first sends a request message to Service A (1). Service A then exchanges request and response messages with Service B (2, 3), Service C (4, 5), and Service D (6. 7). After receiving all three response messages from Services B .C .and D, Service A assembles the collected data into a response message that it returns to Service Consumer A (8). The owner of Service A charges service consumers for each usage of the data retrieval capability. Recently, the owner of Service Consumer A has complained that the data returned by Service A is incorrect, incomplete, and from invalid sources. As evidence, the Service Consumer A owner has presented the owner of Service A with sample messages containing the incorrect and incomplete contents. As a result, the Service Consumer A owner has refused to pay the usage fees. Subsequent to an internal investigation, the owner of Service A determines that the data returned by Service A is consistently correct and complete. There are suspicions that the Service Consumer A owner is altering the original messages and issuing these complaints fraudulently in order to avoid paying the usage fees. How can the owner of Service A prove that Service A is returning correct and complete data and that this data originated from the correct sources?

Eun · Accepted Answer

B) Apply the Data Origin Authentication pattern to verily that request and response messages exchanged by Service Consumer A and Service A and exchanged by Service A and Services B, C, and D originated from the claimed sources and have not been altered prior to transmission. Also, enhance the Service A architecture so that all messages sent to its service consumers are logged.

Eun · Answer

A) Apply the Data Origin Authentication and the Data Confidentiality patterns to ensure that request and response messagesexchanged between Service A and Services B .C, and D are digitally signed and encrypted. This guarantees message integrity and confidentiality.

Eun · Answer

C) Apply the Brokered Authentication pattern to send the security credentials of Service Consumer A to Services B, C, and D.Service A can carry out the brokered authentication logic and therefore act as the intermediary security broker. Upon receiving Service Consumer A's request message, Service A can further verify the credentials against an external certificate authority, if the request is authenticated. Service A can create a signed SAML assertion containing Service Consumer A's credentials and the authorization information. Service A then forwards the original request message and the signed SAML assertion to Services B,C, and D .

Eun · Answer

D) The service contract of Service A can be extended with an ignorable WS-Policy assertion that states that all request and response messages are logged by Service A and that false complaints will be prosecuted.