1 files changed, 86 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/tlsa.go b/vendor/github.com/miekg/dns/tlsa.go
new file mode 100644
index 000000000..34fe6615a
--- /dev/null
+++ b/vendor/github.com/miekg/dns/tlsa.go
@@ -0,0 +1,86 @@
+package dns
+
+import (
+	"crypto/sha256"
+	"crypto/sha512"
+	"crypto/x509"
+	"encoding/hex"
+	"errors"
+	"io"
+	"net"
+	"strconv"
+)
+
+// CertificateToDANE converts a certificate to a hex string as used in the TLSA record.
+func CertificateToDANE(selector, matchingType uint8, cert *x509.Certificate) (string, error) {
+	switch matchingType {
+	case 0:
+		switch selector {
+		case 0:
+			return hex.EncodeToString(cert.Raw), nil
+		case 1:
+			return hex.EncodeToString(cert.RawSubjectPublicKeyInfo), nil
+		}
+	case 1:
+		h := sha256.New()
+		switch selector {
+		case 0:
+			io.WriteString(h, string(cert.Raw))
+			return hex.EncodeToString(h.Sum(nil)), nil
+		case 1:
+			io.WriteString(h, string(cert.RawSubjectPublicKeyInfo))
+			return hex.EncodeToString(h.Sum(nil)), nil
+		}
+	case 2:
+		h := sha512.New()
+		switch selector {
+		case 0:
+			io.WriteString(h, string(cert.Raw))
+			return hex.EncodeToString(h.Sum(nil)), nil
+		case 1:
+			io.WriteString(h, string(cert.RawSubjectPublicKeyInfo))
+			return hex.EncodeToString(h.Sum(nil)), nil
+		}
+	}
+	return "", errors.New("dns: bad TLSA MatchingType or TLSA Selector")
+}
+
+// Sign creates a TLSA record from an SSL certificate.
+func (r *TLSA) Sign(usage, selector, matchingType int, cert *x509.Certificate) (err error) {
+	r.Hdr.Rrtype = TypeTLSA
+	r.Usage = uint8(usage)
+	r.Selector = uint8(selector)
+	r.MatchingType = uint8(matchingType)
+
+	r.Certificate, err = CertificateToDANE(r.Selector, r.MatchingType, cert)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Verify verifies a TLSA record against an SSL certificate. If it is OK
+// a nil error is returned.
+func (r *TLSA) Verify(cert *x509.Certificate) error {
+	c, err := CertificateToDANE(r.Selector, r.MatchingType, cert)
+	if err != nil {
+		return err // Not also ErrSig?
+	}
+	if r.Certificate == c {
+		return nil
+	}
+	return ErrSig // ErrSig, really?
+}
+
+// TLSAName returns the ownername of a TLSA resource record as per the
+// rules specified in RFC 6698, Section 3.
+func TLSAName(name, service, network string) (string, error) {
+	if !IsFqdn(name) {
+		return "", ErrFqdn
+	}
+	p, err := net.LookupPort(network, service)
+	if err != nil {
+		return "", err
+	}
+	return "_" + strconv.Itoa(p) + "._" + network + "." + name, nil
+}