oppi.li
1package identity
2
3import (
4 "context"
5 "errors"
6 "fmt"
7 "net"
8
9 "github.com/bluesky-social/indigo/atproto/syntax"
10)
11
12var (
13 ErrNSIDResolutionFailed = fmt.Errorf("NSID resolution mechanism failed")
14 ErrNSIDNotFound = fmt.Errorf("NSID not associated with a DID")
15)
16
17// Resolves an NSID to a DID, as used for Lexicon resolution (using "_lexicon" DNS TXT record)
18func (d *BaseDirectory) ResolveNSID(ctx context.Context, nsid syntax.NSID) (syntax.DID, error) {
19
20 domain := nsid.Authority()
21 res, err := d.Resolver.LookupTXT(ctx, "_lexicon."+domain)
22
23 // check for NXDOMAIN
24 var dnsErr *net.DNSError
25 if errors.As(err, &dnsErr) {
26 if dnsErr.IsNotFound {
27 return "", ErrNSIDNotFound
28 }
29 }
30
31 if err != nil {
32 return "", fmt.Errorf("%w: %w", ErrNSIDResolutionFailed, err)
33 }
34
35 return parseTXTResp(res)
36}