57 lines
1.5 KiB
Go
57 lines
1.5 KiB
Go
package sshkeys
|
|
|
|
import (
|
|
`crypto/aes`
|
|
`crypto/cipher`
|
|
`errors`
|
|
|
|
// `golang.org/x/crypto/ssh/internal/bcrypt_pbkdf` Golang doesn't let you import "internal" libs. Fine. Lame language.
|
|
`github.com/dchest/bcrypt_pbkdf`
|
|
)
|
|
|
|
func (k *EncryptedSSHKeyV1) setCrypt() error {
|
|
// First we need the KDF (Key Derivation Function).
|
|
if err := k.setKDF(); err != nil {
|
|
return err
|
|
}
|
|
// And then we set the actual cipher (the thing that does the encrypting).
|
|
if err := k.setCipher(); err != nil {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (k *EncryptedSSHKeyV1) setCipher() error {
|
|
switch k.CipherName {
|
|
case CipherAes256Ctr:
|
|
if k.Crypt.Cipher, err = aes.NewCipher(k.Crypt.PrivateKey); err != nil {
|
|
return err
|
|
} else {
|
|
k.Crypt.Stream = cipher.NewCTR(k.Crypt.Cipher, k.Crypt.CryptSalt)
|
|
// Can then be used as k.Crypt.Stream.XORKeyStream(dst []byte, src []byte)
|
|
}
|
|
default:
|
|
return errors.New("could not find Cipher")
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (k *EncryptedSSHKeyV1) setKDF() error {
|
|
// Upstream only currently supports bcrypt_pbkdf ("bcrypt").
|
|
// This should always eval to true, but is here for future planning in case other KDF are implemented.
|
|
switch k.KDFName {
|
|
case KdfBcrypt:
|
|
if k.Crypt.CryptKey, err = bcrypt_pbkdf.Key(k.Passphrase,
|
|
k.KDFOpts.Salt,
|
|
int(k.KDFOpts.Rounds),
|
|
kdfKeyLen + len(k.KDFOpts.Salt),
|
|
); err != nil {
|
|
return err
|
|
} else {
|
|
k.Crypt.PrivateKey = k.Crypt.CryptKey[0:kdfSplit]
|
|
k.Crypt.CryptSalt = k.Crypt.CryptKey[kdfSplit:]
|
|
}
|
|
default:
|
|
return errors.New("could not find KDF")
|
|
}
|
|
} |