The Windows 2012 DNS Server must be configured with the DS RR carrying the signature for the RR that contains the public key of the child zone.

If name server replies are invalid or cannot be validated, many networking functions and communication would be adversely affected. With DNS, the presence of Delegation Signer (DS) records associated with child zones informs clients of the security status of child zones. These records are crucial to the DNSSEC chain of trust model. Each parent domain's DS record is used to verify the DNSKEY record in its sub domain, from the top of the DNS hierarchy down.A DNS server is an example of an information system providing name/address resolution service. Digital signatures and cryptographic keys are examples of additional artifacts. DNS resource records are examples of authoritative data. Applications other than the DNS, to map between host/service names and network addresses, must provide other means to assure the authenticity and integrity of response data. In DNS, trust in the public key of the source is established by starting from a trusted name server and establishing the chain of trust down to the current source of response through successive verifications of signature of the public key of a child by its parent.A trust anchor is an authoritative entity represented via a public key and associated data. It is used in the context of public key infrastructures, X.509 digital certificates, and Domain Name System Security Extensions (DNSSEC).When there is a chain of trust, usually the top entity to be trusted becomes the trust anchor. A certification path starts with the subject certificate and proceeds through a number of intermediate certificates up to a trusted root certificate. In DNS, a trust anchor is a DNSKEY that is placed into a validating resolver so the validator can cryptographically validate the results for a given request back to a known public key (the trust anchor).An example means to indicate the security status of child subspaces is through the use of delegation signer (DS) resource records in the DNS.Path validation is necessary for a relying party to make an informed trust decision when presented with any certificate not already explicitly trusted. Without path validation and a chain of trust, there can be no trust that the data integrity authenticity has been maintained during a transaction.

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Note: This check is Not applicable for Windows 2012 DNS Servers that only host Active Directory integrated zones or for Windows 2012 DNS servers on a Classified network. Validate this check from the Windows 2012 DNS server being configured/reviewed. Log on to the Windows 2012 DNS server using the account designated as Administrator or DNS Administrator. Determine a valid host in the zone. Open the Windows PowerShell prompt on the Windows 2012 DNS server being configured/reviewed. Issue the following command: (Replace www.zonename.mil with a FQDN of a valid host in the zone being validated. Replace ###.###.###.### with the FQDN or IP address of the Windows 2012 DNS Server hosting the signed zone.) resolve-dnsname www.zonename.mil -server ###.###.###.### -dnssecok NOTE: It is important to use the -server switch followed by the DNS Server name/IP address. The result should show the "A" record results. In addition, the results should show QueryType: RRSIG with an expiration, date signed, signer and signature, similar to the following: Name: www.zonename.mil QueryType: RRSIG TTL: 189 Section: Answer TypeCovered: CNAME Algorithm: 8 LabelCount: 3 OriginalTtl: 300 Expiration: 11/21/2014 10:22:28 PM Signed: 10/22/2014 10:22:28 PM Signer: zonename.mil Signature: {87, 232, 34, 134...} Name: origin-www.zonename.mil QueryType: A TTL: 201 Section: Answer IP4Address: ###.###.###.### If the results do not show the RRSIG and signature information, this is a finding.

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Sign, or re-sign, the hosted zone(s) on the DNS server being validated. Log on to the Windows 2012 DNS server using the account designated as Administrator or DNS Administrator. Press Windows Key + R, execute dnsmgmt.msc. On the opened DNS Manager snap-in from the left pane, expand the server name for the DNS server, and then expand Forward Lookup Zones. From the expanded list, right-click to select the zone (repeat for each hosted zone), point to DNSSEC, and then click Sign the Zone, either using approved saved parameters or approved custom parameters.

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SV-73095r5_rule The Windows 2012 DNS Server must be configured with the DS RR carrying the signature for the RR that contains the public key of the child zone.

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