Domain Name System Security Extensions: Difference between revisions

Revision as of 02:22, 15 May 2023

Revision as of 02:43, 15 May 2023

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==Overview==

The original design of the Domain Name System did not include any security features. It was conceived only as a scalable distributed system. The Domain Name System Security Extensions (DNSSEC) attempt to add security, while maintaining [[backward compatibility]]. Request for Comments{{IETF RFC|3833}} documents some of the known threats to the DNS, and their solutions in DNSSEC.

DNSSEC was designed to protect applications using DNS from accepting forged or manipulated DNS data, such as that created by [[DNS cache poisoning]]. All answers from DNSSEC protected zones are [[digital signature|digitally signed]].<ref>{{Cite IETF |last1=Herzberg |first1=Amir |last2=Shulman |first2=Haya |year=2014 |title=Retrofitting Security into Network Protocols: The Case of DNSSEC |url=https://ieeexplore.ieee.org/document/6756846 |journal=IEEE Internet Computing |volume=18 |issue=1 |pages=66–71 |doi=10.1109/MIC.2014.14 |s2cid=12230888 |issn=1089-7801}}</ref> By checking the digital signature, a DNS resolver is able to check if the information is identical (i.e. unmodified and complete) to the information published by the zone owner and served on an authoritative DNS server. While protecting IP addresses is the immediate concern for many users, DNSSEC can protect any data published in the DNS, including text records (TXT) and mail exchange records (MX), and can be used to bootstrap other security systems that publish references to cryptographic certificates stored in the DNS such as Certificate Records ([[CERT record]]s, RFC{{IETF RFC|4398}}), [[Secure Shell|SSH]] fingerprints ([[SSHFP record|SSHFP]], RFC{{IETF RFC|4255}}), [[IPSec]] public keys (IPSECKEY, {{IETF RFC| 4025}}), [[Transport Layer Security|TLS]] Trust Anchors ([[TLSA]], {{IETF RFC | 6698 }}), or Encrypted Client Hello (SVCB/HTTPS records for ECH, <ref>{{cite IETF | url=https://datatracker.ietf.org/doc/draft-ietf-dnsop-svcb-https/ | title=Draft-ietf-dnsop-SVCB-HTTPS-10 - Service binding and parameter specification via the DNS (DNS SVCB and HTTPS RRS) }}</ref> <ref>{{cite newsIETF | url=https://datatracker.ietf.org/doc/draft-ietf-tls-esni/ | title=Draft-ietf-TLS-esni-14 - TLS Encrypted Client Hello }}</ref>).

DNSSEC ''does not'' provide confidentiality of data; in particular, all DNSSEC responses are authenticated but not encrypted. DNSSEC ''does not'' protect against [[denial of service|DoS]] attacks directly, though it indirectly provides some benefit (because signature checking allows the use of potentially untrustworthy parties).{{citation needed|date=February 2013}}