--- /dev/null
+// GoGOST -- Pure Go GOST cryptographic functions library
+// Copyright (C) 2015-2023 Sergey Matveev <stargrave@stargrave.org>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, version 3 of the License.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+// DANE's SPKI hash calculator
+package main
+
+import (
+ "crypto/sha256"
+ "crypto/x509"
+ "encoding/hex"
+ "encoding/pem"
+ "flag"
+ "fmt"
+ "io"
+ "log"
+ "os"
+)
+
+func main() {
+ flag.Parse()
+ data, err := io.ReadAll(os.Stdin)
+ if err != nil {
+ log.Fatalln(err)
+ }
+ b, _ := pem.Decode(data)
+ if b == nil || b.Type != "CERTIFICATE" {
+ log.Fatalln("no CERTIFICATE")
+ }
+ cer, err := x509.ParseCertificate(b.Bytes)
+ if err != nil {
+ log.Fatalln(err)
+ }
+ h := sha256.Sum256(cer.RawSubjectPublicKeyInfo)
+ fmt.Println(hex.EncodeToString(h[:]))
+}