Service Consumer A sends a request to Service A (1). Service A replies with an acknowledgement message (2) and then processes the request and sends a request message to Service B (3). This message contains confidential financial data. Service B sends three different request messages together with its security credentials to Services C.
D.
and E (4, 5, 6). Upon successful authentication, Services C.
D. and E store the data from the message in separate databases (7.8, 9). Services B.
C.D, and E belong to Service Inventory A, which further belongs to Organization B.
Service Consumer A and Service A belong to Organization A.

Organization B decides to create a new service inventory (Service Inventory B) for services that handle confidential data. Access to these services is restricted by allocating Service Inventory B its own private network. Access to this private network is further restricted by a dedicated firewall. Services C, D and E are moved into Service Inventory B, and as a result. Service B can no longer directly access these services.
How can this architecture be changed to allow Service B to access Services C, D and E in a manner that does not jeopardize the security of Service Inventory B while also having a minimal impact on the service composition's performance?

• A. The Brokered Authentication pattern is applied by extending the firewall functionality with a single sign-on mechanism. Because the firewall already restricts accesses to Service Inventory B, adding authentication logic to the firewall optimizes the performance of the overall security architecture. Service B needs to be authenticated by the authentication broker only once in order to get a security token that can be used to access Services C, D, and E.
  This eliminates the need for Service B to authenticate several times during the same service composition.
• B. The Service Perimeter Guard pattern is applied together with the Message Screening pattern. A new perimeter service is created specifically for Service Inventory B.
  This service filters all messages before they reach the firewall and further evaluates the IP address of the messages to verify the identity of the message originators. If the originator is successfully authenticated, then the perimeter guard checks the request message for potentially malicious content. If the request message does not contain malicious content, it is sent through the firewall to proceed to Services C, D, and E for further processing.
• C. The Service Perimeter Guard pattern is applied together with the Brokered Authentication pattern. A new perimeter service is created to intercept all request messages sent to services inside the private network (inside Service Inventory B), before they reach the firewall. The perimeter service also acts as the authentication broker that authenticates request messages sent to Services C, D, and E by evaluating the accompanying security credentials and issuing a security token to be used by Service B when accessing Services C, D, and E.
• D. The Data Confidentiality pattern is applied together with the Direct Authentication pattern. A new utility service is created to validate request messages sent to Service Inventory B.
  Service B must encrypt the message content using the utility service's public key and attach its own digital certificate to the request message. This message is first evaluated by the firewall to filter out requests from disallowed sources and can then be forwarded to the utility service, which then verifies the identity of the message originator (using a digital certificate) and decrypts the request message contents. If the originator is authorized to access Services C, D, and E, the appropriate request messages are sent to these services.

Service Consumer A submits a request message with security credentials to Service A (1).
The identity store that Service A needs to use in order to authenticate the security credentials can only be accessed via a legacy system that resides in a different service inventory. Therefore, to authenticate Service Consumer A, Service A must first forward the security credentials to the legacy system (2). The legacy system then returns the requested identity to Service A (3). Service A authenticates Service Consumer A against the identity received from the legacy system. If the authentication is successful, Service A retrieves the requested data from Database A (4), and returns the data in a response message sent back to Service Consumer A (5).
Service A belongs to Service Inventory A which further belongs to Security Domain A and the legacy system belongs to Service Inventory B which further belongs to Security Domain
B. (The legacy system is encapsulated by other services within Service Inventory B, which are not shown in the diagram.) These two security domains trust each other.
Communication between Service A and the legacy system is kept confidential using transport-layer security.

No intermediary service agents currently exist between the two service inventories.
However, it has been announced that due to the introduction of new systems, some intermediary service agents may be implemented in the near future. Additionally, the legacy system has been scheduled for retirement and will be replaced by a new identity management system that will provide a new identity store. Because the new identity store will need to serve many different systems, there are concerns that it could become a performance bottleneck. As a result, services (including Service A and other services in Security Domains A and B) will not be allowed to directly access the new identity store.
Which of the following statements describes a solution that can accommodate the requirements of the new identity store, the authentication requirements of Service A, and can further ensure that message exchanges between Security Domains A and B remain confidential after intermediary service agents are introduced?

• A. Apply the Trusted Subsystem pattern to implement a utility service abstracting the new identity management system. Service A forwards Service Consumer As credentials to the utility service to verify Service Consumer As identity. The utility service authenticates the request originating from Service A.
  After successful authentication, the utility service uses its own credentials to retrieve the requested identity, and then send the identity to Service A, Therefore, effectively reducing the processing need of the identity management system.
  The current transport-layer security can still be used, in order to secure the communication between Service A and the new utility service, as it more efficient than the message-layer security.
• B. Replicate the identity database used by the new identity management system. Because the Security Domains A and B trust each other, protection of the identity store is guaranteed. Use Service Agents to monitor changes to the identity database used by the new identity management system and to update the replica. This would satisfy the security needs of Service A, would eliminate the need to request services from Service Inventory B, and ensure that current identity information is available for Service A.
  Because Service A would not need to access services across different trust domains, the current transport- layer security is sufficient.
• C. Apply the Trusted Subsystem pattern by abstracting away the new identity management system using a utility service that authenticates the request from Service A and then uses its own credentials to retrieve the requested identity from the new identity management system. For the utility service to authenticate Service As request, it needs to be provisioned with a new identity database that contains identities for all authorized service consumers of the new utility service. In order to secure the communication between Service A and the new utility service, use message-layer security as it provides security over multiple hops considering the need to secure the message in case an intermediary is introduced in future.
• D. Apply the Brokered Authentication pattern to establish an authentication broker. Instead of Service A directly authenticating Service Consumer A, Service Consumer A submits a request message with security credentials to the authentication broker, which authenticates Service Consumer A against the new identity store and then issues a SAML token to Service Consumer A that it can use for message exchanges with other services, if necessary. In order to secure cross-service inventory message exchanges, the Data Confidentiality pattern is applied to establish message-layer security.

Service Consumer A sends a request message to Service A (1), after which Service A sends a request message to Service B (2). Service B forwards the message to have its contents calculated by Service C (3). After receiving the results of the calculations via a response message from Service C (4), Service B then requests additional data by sending a request message to Service D (5). Service D retrieves the necessary data from Database A (6), formats it into an XML document, and sends the response message containing the XML-formatted data to Service B (7). Service B appends this XML document with the calculation results received from Service C, and then records the entire contents of the XML document into Database B (8). Finally, Service B sends a response message to Service A (9) and Service A sends a response message to Service Consumer A (10).
Services A, B and D are agnostic services that belong to Organization A and are also being reused in other service compositions. Service C is a publicly accessible calculation service that resides outside of the organizational boundary. Database A is a shared database used by other systems within Organization A and Database B is dedicated to exclusive access by Service B.

Recently, Service D received request messages containing improperly formatted database retrieval requests. All of these request messages contained data that originated from Service C.
There is a strong suspicion that an attacker from outside of the organization has been attempting to carry out SOL injection attacks. Furthermore, it has been decided that each service that writes data to a database must keep a separate log file that records a timestamp of each database record change. Because of a data privacy disclosure requirement used by Organization A, the service contracts of these services need to indicate that this logging activity may occur.
How can the service composition architecture be improved to avoid SQL injection attacks originating from Service C - and - how can the data privacy disclosure requirement be fulfilled?

• A. Apply the Data Origin Authentication pattern to authenticate data received from Service C.
  Service C digitally signs any data sent in response messages to Service B.
  Service B can then verify that the data has not been modified during transit and that it originated from Service C.
  Secondly, update the service contracts for Services B and D with an ignorable WS-Policy assertion that communicates the possibility of the logging activity. The service contracts for Services B and D are updated with an optional WS-Policy assertion that provides service consumers with the option of complying to the logging requirements.
• B. Apply the Service Perimeter Guard pattern together with the Message Screening pattern in order to establish a perimeter service with message screening logic. Position the perimeter service between Service C and Service B.
  The message screening logic rejects or filters out potentially harmful content in messages sent from Service C, prior to being forwarded to Service B.
  Secondly, update the service contracts for Services B and D with an optional WS-Policy assertion that provides service consumers with the option of complying to the logging requirements.
• C. Apply the Data Origin Authentication pattern to authenticate data received from Service C.
  Service C digitally signs any data sent in response messages to Service B.
  Service B can then verify that the data has not been modified during transit and that it originated from Service C.
  Secondly, update the service contracts for Services B and D with an ignorable WS-Policy assertion that communicates the possibility of the logging activity.
• D. Apply the Message Screening pattern in order to establish a service agent with message screening logic. Position the service agent between Service C and Service B.
  The service agent's message screening logic can reject or filter out potentially harmful content in messages sent from Service C, before being processed by Service B.
  Secondly, update the service contracts for Services B and D with an ignorable WS-Policy assertion that communicates the possibility of the logging activity.