57 lines
2.2 KiB
Go
57 lines
2.2 KiB
Go
package kdf
|
|
|
|
import (
|
|
"bytes"
|
|
)
|
|
|
|
// KDF is a type of KDF (Key Derivation Function).
|
|
type KDF interface {
|
|
// Name returns the string form of the KDF name.
|
|
Name() (name string)
|
|
// NameBytes returns the Name result but in bytes with a leading uint32 bytecount packed in.
|
|
NameBytes() (name []byte)
|
|
// Rounds returns the number of rounds used in derivation.
|
|
Rounds() (rounds uint32)
|
|
// Salt returns the salt bytes.
|
|
Salt() (salt []byte)
|
|
// Setup initializes the KDF with the given derivation secret (password) and KDF options.
|
|
Setup(secret, salt []byte, rounds, keyLen uint32) (err error)
|
|
// DeriveKey derives the key. Setup (or SetupAuto) must have been run first.
|
|
DeriveKey() (key []byte, err error)
|
|
// SetupAuto configures a partially reconstructed KDF options that were parsed from GetKdfFromBytes (if KDF.AutoOK returns true).
|
|
SetupAuto(secret []byte, keyLen uint32) (err error)
|
|
// AutoOK returns true if all components were able to be parsed from GetKdfFromBytes.
|
|
AutoOK() (ok bool)
|
|
// IsPlain returns true if this is a "null" kdf; i.e. no derivation is actually performed.
|
|
IsPlain() (plain bool)
|
|
// PackedBytes returns the bytes suitable for serializing into a key file.
|
|
PackedBytes() (buf *bytes.Reader, err error)
|
|
// addSalt adds the salt as parsed from the private key.
|
|
addSalt(salt []byte) (err error)
|
|
// addRounds adds the rounds as parsed from the private key.
|
|
addRounds(rounds uint32) (err error)
|
|
}
|
|
|
|
/*
|
|
BcryptPbkdf combines bcrypt hashing algorithm with PBKDF2 key derivation.
|
|
|
|
(bcrypt) https://www.usenix.org/legacy/events/usenix99/provos/provos_html/node1.html
|
|
(PBKDF2) https://datatracker.ietf.org/doc/html/rfc2898
|
|
http://www.tedunangst.com/flak/post/bcrypt-pbkdf
|
|
*/
|
|
type BcryptPbkdf struct {
|
|
// salt is used to salt the hash for each round in rounds.
|
|
salt []byte
|
|
// rounds controls how many iterations of salting/hashing is done.
|
|
rounds uint32
|
|
// keyLen is how long the derived key should be in bytes.
|
|
keyLen uint32
|
|
// secret is the "passphrase" used to seed the key creation.
|
|
secret []byte
|
|
// key is used to store the derived key.
|
|
key []byte
|
|
}
|
|
|
|
// Null is a dummy KDF that is used for unencrypted/plain SSH private keys. It literally does nothing.
|
|
type Null struct{}
|