1package dns
2
3import (
4	"crypto/x509"
5	"net"
6	"strconv"
7)
8
9// Sign creates a TLSA record from an SSL certificate.
10func (r *TLSA) Sign(usage, selector, matchingType int, cert *x509.Certificate) (err error) {
11	r.Hdr.Rrtype = TypeTLSA
12	r.Usage = uint8(usage)
13	r.Selector = uint8(selector)
14	r.MatchingType = uint8(matchingType)
15
16	r.Certificate, err = CertificateToDANE(r.Selector, r.MatchingType, cert)
17	return err
18}
19
20// Verify verifies a TLSA record against an SSL certificate. If it is OK
21// a nil error is returned.
22func (r *TLSA) Verify(cert *x509.Certificate) error {
23	c, err := CertificateToDANE(r.Selector, r.MatchingType, cert)
24	if err != nil {
25		return err // Not also ErrSig?
26	}
27	if r.Certificate == c {
28		return nil
29	}
30	return ErrSig // ErrSig, really?
31}
32
33// TLSAName returns the ownername of a TLSA resource record as per the
34// rules specified in RFC 6698, Section 3.
35func TLSAName(name, service, network string) (string, error) {
36	if !IsFqdn(name) {
37		return "", ErrFqdn
38	}
39	p, err := net.LookupPort(network, service)
40	if err != nil {
41		return "", err
42	}
43	return "_" + strconv.Itoa(p) + "._" + network + "." + name, nil
44}
45