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State of DNS Security Extensions. Edward Lewis February 26, 2001 APRICOT 2001 Panel. Agenda. Brief overview of DNS Security Extensions Current state of specifications Current state of software Efforts underway. DNSSEC Components. Name server to name server protections
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State of DNS Security Extensions Edward Lewis February 26, 2001 APRICOT 2001 Panel
Agenda • Brief overview of DNS Security Extensions • Current state of specifications • Current state of software • Efforts underway
DNSSEC Components • Name server to name server protections • Digital signatures, KEY, SIG, NXT records • Scaleable, Internet-wide transfers • Query/Response protections • TSIG addition to message, also a digital sig approach • Resolver to "default" name server, zone transfer • Publication of certificates • Distribution of X.509, PGP certificates, CERT record • Dynamic update security • Authentication and authorization to change zones
DNSSEC in the network top level domain root server authoritative name server KEY RR, SIG RR, NXT RR conference machine TSIG recursive (conference net) name server
IETF Status • The current document set is at the Proposed Standard level • Documents are listed in upcoming slides • The documents are to be rewritten as early experience is gained • The goal is to progress to Draft Standard in 2002
Implementations • ISC's BIND • First in version 8.2 • Full implementations starting in version 9 • Current version 9.1.x • Some implementations in other code bases, none are publicly or widely available
KEY, SIG and NXT • Documents • RFC 2535, Basic definition • RFC 2536, 2537 Key and signature algorithms • RFC 2539 Diffie-Hellman keys • Updates to this set • RFC 3008 Signing authorization model • More coming soon
What works • Key generation • Making, storing keys • Signing and loading zones • Addition of signatures, NXTs, to zones • Basic validation of data • Resolver fetches keys and verifies signatures
Remaining Issues • Validation of child by parent (delegator) • Child zone keys have to signed by parent zone • Impact on high-volume TLDs • Negative response issues • NXT record does not satisfy everyone • Impact on staff operations • Management and protection of keys • Need to sign zone data at intervals • regular intervals - week? month? year? • Interaction with parent zone
Query/Response • Documents • RFC 2535, in the basic definition • Updates • RFC 2845 Secret Key Transaction (TSIG) • RFC 2931 Public Key Query/Response approach
What works • Use of TSIG for zone transfers • Addition of TSIG to authoritative servers to protect NOTIFY and AXFR • Use of TSIG to authorize dynamic updates • Updates can be restricted based upon the key used to sign request
Remaining Issues • Distributing and Configuring Secrets for general queries • General purpose queries, larger scale • Where is the secret stored on a multiuser machine? • Use of TKEY and SIG(0) • Not in widespread use, not much experience
Publishing Certificates • Documents • RFC 2538 Basic definition • What works • CERT Record, simple addition to DNS • Issues • Software for applications to insert and extract certificates from DNS
Securing Dynamic Update • Documents • RFC 2136 Dynamic Update • RFC 2137 Secure Dynamic Update (not implemented) • RFC 3007 Secure Dynamic Update (implemented)
What Works/Issues • Authorizing updates based upon keys used to sign request • No longer need to trust based upon IP address • Keeping signatures up to date • Data not updated becomes stale • Need tools to fix this
Other issues • Need for applications to make use of these new features • E.g., a secure shell implementation that uses keys from DNS • E.g., a web browser that lets user know if the web site's address was digitally signed for protection • E.g., a simple method for users to publish their personal certificates for email
Who's Working On It • Status meeting summarized in • draft-lewis-state-of-dnssec-00.txt • Minutes of December meeting at San Diego IETF • Attendees • NLnet Labs, Verisign, The Foundation for Internet Infrastructure, Root Server System Advisory Committee, National Institute of Standards and Technology, Defense Information Systems Agency, RIPE NCC, Network Associates, Information Sciences Institute
Summary • DNSSEC is a lot of work to define and implement • Progress is happening, but not at a lightening-fast rate • There is a lot of interest in the technology • No matter the outcome, maintaining security will always increase workload, • We do want to keep the increase to a minimum