dns/dane.go

44 lines
997 B
Go

package dns
import (
"crypto/sha256"
"crypto/sha512"
"crypto/x509"
"encoding/hex"
"errors"
)
// 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:
h.Write(cert.Raw)
return hex.EncodeToString(h.Sum(nil)), nil
case 1:
h.Write(cert.RawSubjectPublicKeyInfo)
return hex.EncodeToString(h.Sum(nil)), nil
}
case 2:
h := sha512.New()
switch selector {
case 0:
h.Write(cert.Raw)
return hex.EncodeToString(h.Sum(nil)), nil
case 1:
h.Write(cert.RawSubjectPublicKeyInfo)
return hex.EncodeToString(h.Sum(nil)), nil
}
}
return "", errors.New("dns: bad MatchingType or Selector")
}