Shared wire-format representation for DANE certificate-binding records: the TLSA record (RFC 6698 section 2.1, DANE for TLS) and the SMIMEA record (RFC 8162 section 2, DANE for S/MIME). The type parameter n (either N_tlsa or N_smimea) determines the RR type. Each has its own type synonym (T_tlsa, T_smimea) and matching record pattern synonym (T_TLSA, T_SMIMEA) with the corresponding field-name prefix (tlsa, smimea). The role of X_tlsa is nominal: the wire format is shared but the two RR types bind to different protocols, so T_tlsa and T_smimea are not coercible.

                     1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Cert. Usage  |   Selector    | Matching Type |               /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+               /
/                                                               /
/                 Certificate Association Data                  /
/                                                               /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

If a received message carries a payload shorter than 3 bytes the record is returned as an opaque RData of the corresponding RRTYPE with the truncated bytes as its value; DANE validators should treat such records as present but "unusable".

Derived Ord is canonical (RFC 4034 section 6.2).

See T_sshfp for the SSH host-key fingerprint record and T_openpgpkey for the OpenPGP key record — both also live in this module.

X_tlsa specialised to TLSA records.

X_tlsa specialised to SMIMEA records.

The SSHFP resource record (RFC 4255 section 3.1) — a fingerprint of an SSH host public key. Three fields: an 8-bit algorithm tag (matches the SSH key algorithm), an 8-bit fingerprint type tag (SHA-1, SHA-256, ...), and the fingerprint bytes.

                    1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   algorithm   |    fp type    |                               /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               /
/                                                               /
/                          fingerprint                          /
/                                                               /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

See X_tlsa / T_openpgpkey for the other DANE-style records in this module.

The OPENPGPKEY resource record (RFC 7929 section 2.2) — an OpenPGP transferable public key, carried as raw bytes (no ASCII armor, no base64). Single-field; presented in base64 form.

See X_tlsa / T_sshfp for the other DANE-style records in this module.