Added ed25519-converter script

scripts/ed25519-converter.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"bufio"
+	"crypto/ed25519"
+	"encoding/base64"
+	"encoding/pem"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+
+	"golang.org/x/crypto/ssh"
+)
+
+func main() {
+	key := ""
+
+	fmt.Println("Key:")
+	_, _ = fmt.Scan(&key)
+
+	reader := bufio.NewReader(os.Stdin)
+	fmt.Print("Passphrase: ")
+	passphrase, _ := reader.ReadString('\n')
+	passphrase = strings.TrimSpace(passphrase)
+
+	keyBytes, err := base64.StdEncoding.DecodeString(key)
+	if err != nil {
+		fmt.Println("Invalid base64:", err)
+		return
+	}
+	if len(keyBytes) != 64 {
+		fmt.Println("Invalid key length:", len(keyBytes))
+		return
+	}
+
+	// Use the first 32 bytes as private seed
+	privKey := ed25519.NewKeyFromSeed(keyBytes[:32])
+
+	var pemBlock *pem.Block
+	hasPassphrase := passphrase != "none"
+	if hasPassphrase {
+		fmt.Printf("Encrypting with passphrase: '%s'\n", passphrase)
+		pemBlock, err = ssh.MarshalPrivateKeyWithPassphrase(privKey, "eko", []byte(passphrase))
+	} else {
+		fmt.Println("Encrypting without passphrase")
+		pemBlock, err = ssh.MarshalPrivateKey(privKey, "eko")
+	}
+
+	if err != nil {
+		fmt.Println("failed private key marshaling", err)
+		return
+	}
+	err = pem.Encode(os.Stdout, pemBlock)
+	if err != nil {
+		fmt.Println("pem encoding to file error:", err)
+		return
+	}
+
+	fmt.Println("randomart")
+	printRandomart(privKey)
+}
+
+func printRandomart(key ed25519.PrivateKey) {
+	pub, err := ssh.NewPublicKey(key.Public())
+	if err != nil {
+		panic(err)
+	}
+
+	tmpfile, err := os.CreateTemp("", "id_ed25519.pub")
+	if err != nil {
+		panic(err)
+	}
+	defer os.Remove(tmpfile.Name())
+
+	tmpfile.Write(ssh.MarshalAuthorizedKey(pub))
+	tmpfile.Close()
+
+	cmd := exec.Command("ssh-keygen", "-lvf", tmpfile.Name())
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.Run()
+}

scripts/go.mod

@@ -0,0 +1,7 @@
+module scripts
+
+go 1.24.5
+
+require golang.org/x/crypto v0.41.0
+
+require golang.org/x/sys v0.35.0 // indirect

scripts/go.sum

@@ -0,0 +1,6 @@
+golang.org/x/crypto v0.41.0 h1:WKYxWedPGCTVVl5+WHSSrOBT0O8lx32+zxmHxijgXp4=
+golang.org/x/crypto v0.41.0/go.mod h1:pO5AFd7FA68rFak7rOAGVuygIISepHftHnr8dr6+sUc=
+golang.org/x/sys v0.35.0 h1:vz1N37gP5bs89s7He8XuIYXpyY0+QlsKmzipCbUtyxI=
+golang.org/x/sys v0.35.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
+golang.org/x/term v0.34.0 h1:O/2T7POpk0ZZ7MAzMeWFSg6S5IpWd/RXDlM9hgM3DR4=
+golang.org/x/term v0.34.0/go.mod h1:5jC53AEywhIVebHgPVeg0mj8OD3VO9OzclacVrqpaAw=