remove format/openssh.go

this is unnecessary now that x/crypto/ssh.MarshalPrivateKey has been
added

cmd/cmd.go

@@ -718,39 +718,36 @@ func initializeKeypair() error {
 	_, err = os.Stat(privKeyPath)
 	if os.IsNotExist(err) {
 		fmt.Printf("Couldn't find '%s'. Generating new private key.\n", privKeyPath)
-		_, privKey, err := ed25519.GenerateKey(rand.Reader)
+		cryptoPublicKey, cryptoPrivateKey, err := ed25519.GenerateKey(rand.Reader)
 		if err != nil {
 			return err
 		}
 
-		privKeyBytes, err := format.OpenSSHPrivateKey(privKey, "")
+		privateKeyBytes, err := ssh.MarshalPrivateKey(cryptoPrivateKey, "")
 		if err != nil {
 			return err
 		}
 
-		err = os.MkdirAll(filepath.Dir(privKeyPath), 0o755)
-		if err != nil {
+		if err := os.MkdirAll(filepath.Dir(privKeyPath), 0o755); err != nil {
 			return fmt.Errorf("could not create directory %w", err)
 		}
 
-		err = os.WriteFile(privKeyPath, pem.EncodeToMemory(privKeyBytes), 0o600)
-		if err != nil {
+		if err := os.WriteFile(privKeyPath, pem.EncodeToMemory(privateKeyBytes), 0o600); err != nil {
 			return err
 		}
 
-		sshPrivateKey, err := ssh.NewSignerFromKey(privKey)
+		sshPublicKey, err := ssh.NewPublicKey(cryptoPublicKey)
 		if err != nil {
 			return err
 		}
 
-		pubKeyData := ssh.MarshalAuthorizedKey(sshPrivateKey.PublicKey())
+		publicKeyBytes := ssh.MarshalAuthorizedKey(sshPublicKey)
 
-		err = os.WriteFile(pubKeyPath, pubKeyData, 0o644)
-		if err != nil {
+		if err := os.WriteFile(pubKeyPath, publicKeyBytes, 0o644); err != nil {
 			return err
 		}
 
-		fmt.Printf("Your new public key is: \n\n%s\n", string(pubKeyData))
+		fmt.Printf("Your new public key is: \n\n%s\n", publicKeyBytes)
 	}
 	return nil
 }

format/openssh.go

@@ -1,102 +0,0 @@
-// Copyright 2012 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Code originally from https://go-review.googlesource.com/c/crypto/+/218620
-
-// TODO: replace with upstream once the above change is merged and released.
-
-package format
-
-import (
-	"crypto"
-	"crypto/ed25519"
-	"crypto/rand"
-	"encoding/binary"
-	"encoding/pem"
-	"fmt"
-
-	"golang.org/x/crypto/ssh"
-)
-
-const privateKeyAuthMagic = "openssh-key-v1\x00"
-
-type openSSHEncryptedPrivateKey struct {
-	CipherName string
-	KDFName    string
-	KDFOptions string
-	KeysCount  uint32
-	PubKey     []byte
-	KeyBlocks  []byte
-}
-
-type openSSHPrivateKey struct {
-	Check1  uint32
-	Check2  uint32
-	Keytype string
-	Rest    []byte `ssh:"rest"`
-}
-
-type openSSHEd25519PrivateKey struct {
-	Pub     []byte
-	Priv    []byte
-	Comment string
-	Pad     []byte `ssh:"rest"`
-}
-
-func OpenSSHPrivateKey(key crypto.PrivateKey, comment string) (*pem.Block, error) {
-	var check uint32
-	if err := binary.Read(rand.Reader, binary.BigEndian, &check); err != nil {
-		return nil, err
-	}
-
-	var pk1 openSSHPrivateKey
-	pk1.Check1 = check
-	pk1.Check2 = check
-
-	var w openSSHEncryptedPrivateKey
-	w.KeysCount = 1
-
-	if k, ok := key.(*ed25519.PrivateKey); ok {
-		key = *k
-	}
-
-	switch k := key.(type) {
-	case ed25519.PrivateKey:
-		pub, priv := k[32:], k
-		key := openSSHEd25519PrivateKey{
-			Pub:     pub,
-			Priv:    priv,
-			Comment: comment,
-		}
-
-		pk1.Keytype = ssh.KeyAlgoED25519
-		pk1.Rest = ssh.Marshal(key)
-
-		w.PubKey = ssh.Marshal(struct {
-			KeyType string
-			Pub     []byte
-		}{
-			ssh.KeyAlgoED25519, pub,
-		})
-	default:
-		return nil, fmt.Errorf("ssh: unknown key type %T", k)
-	}
-
-	w.KeyBlocks = openSSHPadding(ssh.Marshal(pk1), 8)
-
-	w.CipherName, w.KDFName, w.KDFOptions = "none", "none", ""
-
-	return &pem.Block{
-		Type:  "OPENSSH PRIVATE KEY",
-		Bytes: append([]byte(privateKeyAuthMagic), ssh.Marshal(w)...),
-	}, nil
-}
-
-func openSSHPadding(block []byte, blocksize int) []byte {
-	for i, j := 0, len(block); (j+i)%blocksize != 0; i++ {
-		block = append(block, byte(i+1))
-	}
-
-	return block
-}