The Windows 2012 DNS Server must implement NIST FIPS-validated cryptography for provisioning digital signatures, generating cryptographic hashes, and protecting unclassified information requiring confidentiality.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-58557	WDNS-SC-000031	SV-72987r1_rule		Medium

Description
Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The application must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. The choice of digital signature algorithm will be based on recommended algorithms in well-known standards. NIST's Digital Signature Standard (DSS) [FIPS186] provides three algorithm choices: * Digital Signature Algorithm (DSA) * RSA * Elliptic Curve DSA (ECDSA). Of these three algorithms, RSA and DSA are more widely available and considered candidates of choice for DNSSEC. In terms of performance, both RSA and DSA have comparable signature generation speeds, but DSA is much slower for signature verification. RSA is the recommended algorithm as far as this guideline is concerned. RSA with SHA-1 is currently the only cryptographic algorithm mandated to be implemented with DNSSEC, although other algorithm suites (i.e. RSA/SHA-256, ECDSA) are also specified. It can be expected that name servers and clients will be able to use the RSA algorithm at the minimum. It is suggested that at least one ZSK for a zone use the RSA algorithm. NIST's Secure Hash Standard (SHS) (FIPS 180-3) specifies SHA-1, SHA-224, SHA-256, SHA-384, and SHA-512 as approved hash algorithms to be used as part of the algorithm suite for generating digital signatures using the digital signature algorithms in the NIST's DSS[FIPS186]. It is expected that there will be support for Elliptic Curve Cryptography in the DNSSEC. The migration path for USG DNSSEC operation will be to ECDSA (or similar) from RSA/SHA-1 and RSA/SHA-256 before September 30th, 2015.

Description

Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The application must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. The choice of digital signature algorithm will be based on recommended algorithms in well-known standards. NIST's Digital Signature Standard (DSS) [FIPS186] provides three algorithm choices: * Digital Signature Algorithm (DSA) * RSA * Elliptic Curve DSA (ECDSA). Of these three algorithms, RSA and DSA are more widely available and considered candidates of choice for DNSSEC. In terms of performance, both RSA and DSA have comparable signature generation speeds, but DSA is much slower for signature verification. RSA is the recommended algorithm as far as this guideline is concerned. RSA with SHA-1 is currently the only cryptographic algorithm mandated to be implemented with DNSSEC, although other algorithm suites (i.e. RSA/SHA-256, ECDSA) are also specified. It can be expected that name servers and clients will be able to use the RSA algorithm at the minimum. It is suggested that at least one ZSK for a zone use the RSA algorithm. NIST's Secure Hash Standard (SHS) (FIPS 180-3) specifies SHA-1, SHA-224, SHA-256, SHA-384, and SHA-512 as approved hash algorithms to be used as part of the algorithm suite for generating digital signatures using the digital signature algorithms in the NIST's DSS[FIPS186]. It is expected that there will be support for Elliptic Curve Cryptography in the DNSSEC. The migration path for USG DNSSEC operation will be to ECDSA (or similar) from RSA/SHA-1 and RSA/SHA-256 before September 30th, 2015.

STIG	Date
Microsoft Windows 2012 Server Domain Name System Security Technical Implementation Guide	2015-03-30

Details

Check Text ( C-59429r1_chk )
Log on to the DNS server using the Domain Admin or Enterprise Admin account. 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, click to select the zone. Review the zone's RRs in the right window pane. Review the DNSKEY encryption in the Data column. example: [DNSKEY][RsaSha1][31021] Confirm the encryption algorithm specified in the DNSKEY's Data is at RsaSha1, at a minimum. If the specified encryption algorithm is not RsaSha1 or stronger, this is a finding.

Check Text ( C-59429r1_chk )

Log on to the DNS server using the Domain Admin or Enterprise Admin account.

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, click to select the zone.

Review the zone's RRs in the right window pane.

Review the DNSKEY encryption in the Data column. example: [DNSKEY][RsaSha1][31021]

Confirm the encryption algorithm specified in the DNSKEY's Data is at RsaSha1, at a minimum.

If the specified encryption algorithm is not RsaSha1 or stronger, this is a finding.

Fix Text (F-63941r1_fix)
Sign, or re-sign, the hosted zone(s) on the DNS server being validated. Log on to the DNS server using the Domain Admin or Enterprise Admin account. 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.

Fix Text (F-63941r1_fix)

Sign, or re-sign, the hosted zone(s) on the DNS server being validated.

Log on to the DNS server using the Domain Admin or Enterprise Admin account.

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.