Module doh 

DNS over HTTPS, for the records a stub resolver has no API for: a zone’s nameservers, a handle’s TXT record, a lexicon authority’s TXT record.

RFC 8484 carries DNS’s own wire format over HTTPS. Cloudflare’s and Google’s resolvers also answer a JSON sibling of it: a GET naming the record and its type, answered as application/dns-json. That JSON form is what this speaks. query_url and parse need no network, and lookup makes the request through crate::pinned_client.

Whoever runs the resolver sees every name asked of it, so every caller takes the resolver’s address as a parameter.

Constants

CLOUDFLARE

Cloudflare’s resolver, which answers the JSON form.

JSON_ACCEPT

The Accept header that asks a DoH endpoint for JSON rather than the wire format.

MAX_ANSWER_BYTES

The most of one answer lookup reads. A TXT answer is a few hundred bytes.

TXT

The TXT record type, by its number and its name.

Functions

escape 🔒

Percent-encodes what a hostname may legitimately carry and a query string may not. A hostname is letters, digits, hyphens, dots and underscores (_atproto), so this is a narrow guard against a caller’s typo reaching the resolver as query syntax rather than a general encoder.

lookup

The records of record_type, by number and name, at name, as the resolver at resolver answers: one GET through a client pinned to the resolver’s own addresses, its answer read under MAX_ANSWER_BYTES and by parse.

parse

Reads one answer: the records of type record_type, as strings.

query_url

The URL one query is made at.

status_name 🔒

The DNS RCODEs a public resolver actually answers with, by name.

tidy 🔒

A record’s data as a caller wants to read it: a nameserver without its root dot, a TXT record with its character-string quoting undone, and anything else as it came.