1 files changed, 44 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/dane.go b/vendor/github.com/miekg/dns/dane.go
new file mode 100644
index 000000000..cdaa833ff
--- /dev/null
+++ b/vendor/github.com/miekg/dns/dane.go
@@ -0,0 +1,44 @@
+package dns
+
+import (
+	"crypto/sha256"
+	"crypto/sha512"
+	"crypto/x509"
+	"encoding/hex"
+	"errors"
+	"io"
+)
+
+// CertificateToDANE converts a certificate to a hex string as used in the TLSA or SMIMEA records.
+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 MatchingType or Selector")
+}