SSHFP record explained

A Secure Shell fingerprint record (abbreviated as SSHFP record) is a type of resource record in the Domain Name System (DNS) which identifies SSH keys that are associated with a host name. The acquisition of an SSHFP record needs to be secured with a mechanism such as DNSSEC for a chain of trust to be established.

Structure

(Name): The name of the object to which the resource record belongs (optional)

(TTL): Time to live (in seconds). Validity of Resource Records (optional)

(Class): Protocol group to which the resource record belongs (optional)

(Algorithm): Algorithm (0: reserved, 1: RSA, 2: DSA, 3: ECDSA, 4: Ed25519, 6: Ed448)

(Type): Algorithm used to hash the public key (0: reserved, 1: SHA-1, 2: SHA-256)

(Fingerprint): Hexadecimal representation of the hash result, as text

Example

In this example, the host with the domain name host.[[example.com]] uses a Ed25519 key with the SHA-256 fingerprint 123456789abcdef67890123456789abcdef67890.

This output would be produced by a ssh-keygen -r host.example.com. command on the target server by reading the existing default SSH host key (Ed25519).^[1] In newer releases of the OpenSSH suite, ssh-keyscan -D $HOSTNAME^[2] can be used to produce a similar result, by connecting to the host over the network.

See also

• List of DNS record types

References

1. Web site: ssh-keygen(1) - OpenBSD manual pages . 2025-05-30 . man.openbsd.org.
2. Web site: ssh-keyscan(1) - OpenBSD manual pages . 2025-05-30 . man.openbsd.org.

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