Arcitura Education S90.20 Exam Dumps

Service A is a publically accessible service that provides free multimedia retrieval capabilities to a range of service consumers. To carry out this functionality, Service A is first invoked by Service Consumer A (1). Based on the nature of the request message received from Service Consumer A, Service A either invokes Service B or Service C .When Service B is invoked by Service A (2A) it retrieves data from publicly available sources (not shown) and responds with the requested data (3A). When Service C is invoked by Service A (2B) it retrieves data from proprietary sources within the IT enterprise (not shown) and responds with the requested data (3B). After receiving a response from Service B or Service C, Service A sends the retrieved data to Service Consumer A (4). Service B does not require service consumers to be authenticated, but Service C does require authentication of service consumers. The service contract for Service A therefore uses WS-Policy alternative policies in order to express the two different authentication requirements to Service Consumer A .When Service Consumer A sends a request message (1), Service A determines whether the request requires the involvement of Service C and then checks to ensure that the necessary security credentials were received as part of the message. If the credentials provided by Service Consumer A are verified. Service A creates a signed SAML assertion and sends it with the request message to Service C (2B) This authentication information is protected by public key encryption However, responses to Service Consumer A's request message (3B, 4) are not encrypted for performance reasons. Recently, the usage of Service C has noticeably declined. An investigation has revealed response messages issued by Service C (3B) have been repeatedly intercepted and accessed by unauthorized and malicious intermediaries. As a result, Service Consumer A has lost confidence in the use of Service A for the retrieval of proprietary data because it is being viewed as a security risk. This is especially troubling, because the owner of Service A had planned to start charging a fee for Service A's ability to provide proprietary data via the use of Service C .How can this service composition architecture be changed to address the security problem with minimal impact on runtime performance?

Show Answer Hide Answer

Service A has two specific service consumers, Service Consumer A and Service Consumer B (1). Both service consumers are required to provide security credentials in order for Service A to perform authentication using an identity store (2). If a service consumer's request message is successfully authenticated, Service A processes the request by exchanging messages with Service B (3) and then Service C (4). With each of these message exchanges, Service A collects data necessary to perform a query against historical data stored in a proprietary legacy system. Service A's request to the legacy system must be authenticated (5). The legacy system only provides access control using a single account. If the request from Service A is permitted, it will be able to access all of the data stored in the legacy system. If the request is not permitted, none of the data stored in the legacy system can be accessed. Upon successfully retrieving the requested data (6), Service A generates a response message that is sent back to either Service Consumer A or B .The legacy system is also used independently by Service D without requiring any authentication. Furthermore, the legacy system has no auditing feature and therefore cannot record when data access from Service A or Service D occurs. If the legacy system encounters an error when processing a request, it generates descriptive error codes. This service composition architecture needs to be upgraded in order to fulfill the following new security requirements:

1. Service Consumers A and B have different access permissions and therefore, data received from the legacy system must be filtered prior to issuing a response message to one of these two service consumers.

2. Service Consumer A's request messages must be digitally signed, whereas request messages from Service Consumer B do not need to be digitally signed. Which of the following statements describes a solution that fulfills these requirements?

Show Answer Hide Answer

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. It was recently discovered that a malicious attacker, posing as Service Consumer A, has been accessing Service A .An investigation revealed that these attacks occurred because security credentials supplied by Service Consumer A were transmitted in plaintext. Furthermore, vulnerabilities to replay attacks and malicious intermediaries have been detected. Which of the following statements describes a solution that can counter these types of attacks?

Also, list the industry standards required by the proposed solution.

Show Answer Hide Answer

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?

Show Answer Hide Answer

Services A, B and C belong to Service Inventory A .Services D, E and F belong to Service Inventory B .Service C acts as an authentication broker for Service Inventory A .Service F acts as an authentication broker for Service Inventory B .Both of the authentication brokers use Kerberos-based authentication technologies. Upon receiving a request message from a service consumer, Services C and F authenticate the request using a local identity store and then use a separate Ticket Granting Service (not shown) to issue the Kerberos ticket to the service consumer. Currently, tickets issued in one service inventory are not valid in the other. For example, if Service A wants to communicate with Services D or E, it must request a ticket from the Service Inventory B authentication broker (Service F). Because Service Inventory A and B trust each other, the current cross-inventory authentication is considered unnecessarily redundant. How can these service inventory architectures be improved to avoid redundant authentication?

Show Answer Hide Answer