TKEY record

TKEY (transaction key) is a record type of the Domain Name System (DNS). TKEY resource records (RRs) can be used in a number of different modes to establish shared keys between a DNS resolver and name server.

TKEY record format

TKEY resource record fields

Field	Description	Length (octets)
NAME	Key name, which must be unique on client and server	Variable
TYPE	TKEY (249)	2
CLASS	Ignored, should be ANY (255)	2
TTL	Ignored, should be 0	4
RDLENGTH	Length of RDATA field	2
RDATA	Variable-length structure containing the timestamp, algorithm, mode, hash data and error	Variable, as per RDLENGTH

Mode field values

• 0 – Reserved
• 1 – Server assignment
• 2 – Diffie–Hellman key exchange
• 3 – Generic Security Service Algorithm for Secret Key Transaction
• 4 – Resolver assignment
• 5 – Key deletion
• 6–65534 – Available
• 65535 – Reserved

See also

• Domain Name System
• List of DNS record types

References

• RFC 2930, "Secret Key Establishment for DNS (TKEY RR)", D. Eastlake, September 2000