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Author SHA1 Message Date
SW
68911b3af4 chore: rename module path to git.janvete.com/seth/caddyview
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The repo lives on Forgejo; the github.com module path was a leftover
identifier. No functional change.
2026-10-17 22:42:21 +02:00
SW
b229cfe264 feat: support aes256-gcm@openssh.com encrypted private keys
x/crypto/ssh only supports aes256-ctr/cbc for private key encryption,
so keys exported from 1Password (aes256-gcm) could not be decrypted even
with the correct passphrase. Decrypt the openssh-key-v1 blob ourselves
(bcrypt_pbkdf ported from x/crypto's internal package, AES-256-GCM via
stdlib, auth tag stored as raw bytes after the encrypted block) and
re-marshal it as an unencrypted key for ssh.ParsePrivateKey.
2026-10-17 22:42:21 +02:00
7 changed files with 234 additions and 8 deletions

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@ -4,8 +4,8 @@ import (
"fmt" "fmt"
"os" "os"
"github.com/janvete/caddyview/internal/sshclient" "git.janvete.com/seth/caddyview/internal/sshclient"
"github.com/janvete/caddyview/internal/tui" "git.janvete.com/seth/caddyview/internal/tui"
"github.com/spf13/cobra" "github.com/spf13/cobra"
) )

2
go.mod
View file

@ -1,4 +1,4 @@
module github.com/janvete/caddyview module git.janvete.com/seth/caddyview
go 1.26.4 go 1.26.4

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@ -0,0 +1,95 @@
// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found at https://go.dev/LICENSE.
//
// Adapted from golang.org/x/crypto/ssh/internal/bcrypt_pbkdf, which is not
// importable (internal package). Implements bcrypt_pbkdf(3) from OpenBSD.
//
// See https://flak.tedunangst.com/post/bcrypt-pbkdf and
// https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libutil/bcrypt_pbkdf.c.
package sshclient
import (
"crypto/sha512"
"errors"
"golang.org/x/crypto/blowfish"
)
const bcryptBlockSize = 32
// bcryptPBKDF derives a key from the password, salt and rounds count,
// returning a []byte of length keyLen that can be used as cryptographic key.
func bcryptPBKDF(password, salt []byte, rounds, keyLen int) ([]byte, error) {
if rounds < 1 {
return nil, errors.New("bcrypt_pbkdf: number of rounds is too small")
}
if len(password) == 0 {
return nil, errors.New("bcrypt_pbkdf: empty password")
}
if len(salt) == 0 || len(salt) > 1<<20 {
return nil, errors.New("bcrypt_pbkdf: bad salt length")
}
if keyLen > 1024 {
return nil, errors.New("bcrypt_pbkdf: keyLen is too large")
}
numBlocks := (keyLen + bcryptBlockSize - 1) / bcryptBlockSize
key := make([]byte, numBlocks*bcryptBlockSize)
h := sha512.New()
h.Write(password)
shapass := h.Sum(nil)
shasalt := make([]byte, 0, sha512.Size)
cnt, tmp := make([]byte, 4), make([]byte, bcryptBlockSize)
for block := 1; block <= numBlocks; block++ {
h.Reset()
h.Write(salt)
cnt[0] = byte(block >> 24)
cnt[1] = byte(block >> 16)
cnt[2] = byte(block >> 8)
cnt[3] = byte(block)
h.Write(cnt)
bcryptHash(tmp, shapass, h.Sum(shasalt))
out := make([]byte, bcryptBlockSize)
copy(out, tmp)
for i := 2; i <= rounds; i++ {
h.Reset()
h.Write(tmp)
bcryptHash(tmp, shapass, h.Sum(shasalt))
for j := 0; j < len(out); j++ {
out[j] ^= tmp[j]
}
}
for i, v := range out {
key[i*numBlocks+(block-1)] = v
}
}
return key[:keyLen], nil
}
var bcryptMagic = []byte("OxychromaticBlowfishSwatDynamite")
func bcryptHash(out, shapass, shasalt []byte) {
c, err := blowfish.NewSaltedCipher(shapass, shasalt)
if err != nil {
panic(err)
}
for i := 0; i < 64; i++ {
blowfish.ExpandKey(shasalt, c)
blowfish.ExpandKey(shapass, c)
}
copy(out, bcryptMagic)
for i := 0; i < 32; i += 8 {
for j := 0; j < 64; j++ {
c.Encrypt(out[i:i+8], out[i:i+8])
}
}
// Swap bytes due to different endianness.
for i := 0; i < 32; i += 4 {
out[i+3], out[i+2], out[i+1], out[i] = out[i], out[i+1], out[i+2], out[i+3]
}
}

View file

@ -9,7 +9,7 @@ import (
"path/filepath" "path/filepath"
"strings" "strings"
"github.com/janvete/caddyview/internal/parser" "git.janvete.com/seth/caddyview/internal/parser"
"golang.org/x/crypto/ssh" "golang.org/x/crypto/ssh"
"golang.org/x/crypto/ssh/agent" "golang.org/x/crypto/ssh/agent"
"golang.org/x/term" "golang.org/x/term"
@ -193,7 +193,7 @@ func unlockWithPassphrase(path string, data []byte) (ssh.Signer, error) {
if err != nil { if err != nil {
return nil, err return nil, err
} }
signer, err := ssh.ParsePrivateKeyWithPassphrase(data, pass) signer, err := parsePrivateKeyWithPassphrase(data, pass)
if err == nil { if err == nil {
return signer, nil return signer, nil
} }
@ -202,6 +202,15 @@ func unlockWithPassphrase(path string, data []byte) (ssh.Signer, error) {
return nil, fmt.Errorf("could not decrypt key in 3 attempts") return nil, fmt.Errorf("could not decrypt key in 3 attempts")
} }
// parsePrivateKeyWithPassphrase handles ciphers beyond what x/crypto/ssh
// supports (aes256-gcm@openssh.com, e.g. 1Password key exports).
func parsePrivateKeyWithPassphrase(data, pass []byte) (ssh.Signer, error) {
if isGCMEncryptedKey(data) {
return parseGCMKey(data, pass)
}
return ssh.ParsePrivateKeyWithPassphrase(data, pass)
}
// agentAuth returns an auth method backed by the SSH agent if SSH_AUTH_SOCK is set. // agentAuth returns an auth method backed by the SSH agent if SSH_AUTH_SOCK is set.
func agentAuth() ssh.AuthMethod { func agentAuth() ssh.AuthMethod {
sock := os.Getenv("SSH_AUTH_SOCK") sock := os.Getenv("SSH_AUTH_SOCK")

View file

@ -0,0 +1,122 @@
package sshclient
import (
"crypto/aes"
"crypto/cipher"
"encoding/pem"
"errors"
"fmt"
"golang.org/x/crypto/ssh"
)
// aes256-gcm@openssh.com is a cipher OpenSSH (and 1Password key exports) may
// use for private key files. golang.org/x/crypto/ssh only supports aes256-ctr
// and aes256-cbc, so these keys are decrypted here and re-marshalled as
// unencrypted openssh-key-v1 blobs that ssh.ParsePrivateKey accepts.
const (
opensshKeyMagic = "openssh-key-v1\x00"
opensshGCMCipher = "aes256-gcm@openssh.com"
gcmTagSize = 16
)
type opensshPrivateKeyHeader struct {
CipherName string
KdfName string
KdfOpts string
NumKeys uint32
PubKey []byte
PrivKeyBlock []byte
// For AEAD ciphers (aes256-gcm@openssh.com) OpenSSH stores the 16-byte
// auth tag as raw bytes after the encrypted block, not inside it.
Rest []byte `ssh:"rest"`
}
// isGCMEncryptedKey reports whether data is an OpenSSH private key encrypted
// with aes256-gcm@openssh.com.
func isGCMEncryptedKey(data []byte) bool {
block, _ := pem.Decode(data)
if block == nil || block.Type != "OPENSSH PRIVATE KEY" {
return false
}
if len(block.Bytes) < len(opensshKeyMagic) || string(block.Bytes[:len(opensshKeyMagic)]) != opensshKeyMagic {
return false
}
var header struct {
CipherName string
Rest []byte `ssh:"rest"`
}
if err := ssh.Unmarshal(block.Bytes[len(opensshKeyMagic):], &header); err != nil {
return false
}
return header.CipherName == opensshGCMCipher
}
// parseGCMKey decrypts an aes256-gcm@openssh.com encrypted OpenSSH private
// key with passphrase and returns the signer.
func parseGCMKey(data, passphrase []byte) (ssh.Signer, error) {
block, _ := pem.Decode(data)
if block == nil || len(block.Bytes) < len(opensshKeyMagic) {
return nil, errors.New("invalid OpenSSH private key PEM")
}
var w opensshPrivateKeyHeader
if err := ssh.Unmarshal(block.Bytes[len(opensshKeyMagic):], &w); err != nil {
return nil, err
}
if w.NumKeys != 1 {
return nil, errors.New("multi-key files are not supported")
}
if w.KdfName != "bcrypt" {
return nil, fmt.Errorf("unknown KDF %q, only supports %q", w.KdfName, "bcrypt")
}
var kdfOpts struct {
Salt string
Rounds uint32
}
if err := ssh.Unmarshal([]byte(w.KdfOpts), &kdfOpts); err != nil {
return nil, err
}
// Same cap as x/crypto/ssh so a hostile file cannot tie up the caller.
const maxRounds = 1 << 11
if kdfOpts.Rounds > maxRounds {
return nil, fmt.Errorf("bcrypt KDF rounds %d exceed maximum %d", kdfOpts.Rounds, maxRounds)
}
// AES-256-GCM: 32-byte key + 12-byte nonce derived by bcrypt_pbkdf.
// The 16-byte auth tag follows the encrypted block as raw bytes;
// gcm.Open expects it appended to the ciphertext.
if len(w.Rest) != gcmTagSize {
return nil, fmt.Errorf("unexpected GCM tag length %d", len(w.Rest))
}
k, err := bcryptPBKDF(passphrase, []byte(kdfOpts.Salt), int(kdfOpts.Rounds), 32+12)
if err != nil {
return nil, err
}
aesCipher, err := aes.NewCipher(k[:32])
if err != nil {
return nil, err
}
gcm, err := cipher.NewGCM(aesCipher)
if err != nil {
return nil, err
}
sealed := make([]byte, 0, len(w.PrivKeyBlock)+gcmTagSize)
sealed = append(sealed, w.PrivKeyBlock...)
sealed = append(sealed, w.Rest...)
plain, err := gcm.Open(nil, k[32:], sealed, nil)
if err != nil {
return nil, err
}
// Re-marshal as an unencrypted key (tag dropped). The plaintext keeps
// its original OpenSSH padding, which ssh.ParsePrivateKey validates.
w.CipherName = "none"
w.KdfName = "none"
w.KdfOpts = ""
w.PrivKeyBlock = plain
w.Rest = nil
raw := make([]byte, 0, len(opensshKeyMagic)+len(plain)+128)
raw = append(raw, opensshKeyMagic...)
raw = append(raw, ssh.Marshal(&w)...)
return ssh.ParsePrivateKey(pem.EncodeToMemory(&pem.Block{Type: "OPENSSH PRIVATE KEY", Bytes: raw}))
}

View file

@ -9,8 +9,8 @@ import (
tea "github.com/charmbracelet/bubbletea" tea "github.com/charmbracelet/bubbletea"
"github.com/charmbracelet/lipgloss" "github.com/charmbracelet/lipgloss"
"github.com/janvete/caddyview/internal/parser" "git.janvete.com/seth/caddyview/internal/parser"
"github.com/janvete/caddyview/internal/sshclient" "git.janvete.com/seth/caddyview/internal/sshclient"
) )
// -- tabs --------------------------------------------------------------------- // -- tabs ---------------------------------------------------------------------

View file

@ -1,6 +1,6 @@
package main package main
import "github.com/janvete/caddyview/cmd" import "git.janvete.com/seth/caddyview/cmd"
func main() { func main() {
cmd.Execute() cmd.Execute()