dkforest

commit 04866a128c4e27444ff8ec82a8b9dbe878eed371
parent f0d0a050f5d58bd47431474fd58c13d244d36dae
Author: n0tr1v <n0tr1v@protonmail.com>
Date:   Sun, 29 Jan 2023 20:05:59 -0800

simple cert verifier

Diffstat:
A
cmd/torsign_verify/main.go
 | 
45
+++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 45 insertions(+), 0 deletions(-)
diff --git a/cmd/torsign_verify/main.go b/cmd/torsign_verify/main.go
@@ -0,0 +1,45 @@
+package main
+
+import (
+	"crypto/ed25519"
+	"encoding/base32"
+	"encoding/base64"
+	"flag"
+	"fmt"
+	"os"
+	"strings"
+)
+
+func main() {
+	var onionAddr, certFile string
+	flag.StringVar(&onionAddr, "onion-address", "", "the_public_onion_address.onion")
+	flag.StringVar(&onionAddr, "a", "", "the_public_onion_address.onion")
+	flag.StringVar(&certFile, "cert", "", "certificate file to validate")
+	flag.StringVar(&certFile, "c", "", "certificate file to validate")
+	flag.Parse()
+
+	certBytes, err := os.ReadFile(certFile)
+	if err != nil {
+		panic(err)
+	}
+	cert := string(certBytes)
+	cert = strings.TrimSpace(cert)
+	cert = strings.TrimPrefix(cert, "-----BEGIN SIGNED MESSAGE-----\n")
+	cert = strings.TrimSuffix(cert, "\n-----END SIGNATURE-----")
+	parts := strings.Split(cert, "\n-----BEGIN SIGNATURE-----\n")
+	msg := parts[0]
+	sig, _ := base64.StdEncoding.DecodeString(strings.ReplaceAll(parts[1], "\n", ""))
+	pub := identityKeyFromAddress(onionAddr)
+	if ed25519.Verify(pub, []byte(msg), sig) {
+		fmt.Println("valid signature")
+	} else {
+		fmt.Println("invalid signature")
+	}
+}
+
+func identityKeyFromAddress(onionAddr string) ed25519.PublicKey {
+	trimmedAddr := strings.TrimSuffix(onionAddr, ".onion")
+	upperAddr := strings.ToUpper(trimmedAddr)
+	decodedAddr, _ := base32.StdEncoding.DecodeString(upperAddr)
+	return decodedAddr[:32]
+}