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

Description

<VulnDiscussion>Use of weak or untested encryption algorithms undermines the purposes of using 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. Both RSA and DSA have comparable signature generation speeds, but DSA is much slower for signature verification. RSA is the recommended algorithm for this guideline. 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 a 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 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 30 September 2015.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>