package sr25519
|
|
|
|
import (
|
|
"crypto/subtle"
|
|
"fmt"
|
|
"io"
|
|
|
|
"github.com/tendermint/tendermint/crypto"
|
|
|
|
schnorrkel "github.com/ChainSafe/go-schnorrkel"
|
|
)
|
|
|
|
// PrivKeySize is the number of bytes in an Sr25519 private key.
|
|
const PrivKeySize = 32
|
|
|
|
// PrivKeySr25519 implements crypto.PrivKey.
|
|
type PrivKey []byte
|
|
|
|
// Bytes returns the byte representation of the PrivKey.
|
|
func (privKey PrivKey) Bytes() []byte {
|
|
return []byte(privKey)
|
|
}
|
|
|
|
// Sign produces a signature on the provided message.
|
|
func (privKey PrivKey) Sign(msg []byte) ([]byte, error) {
|
|
var p [PrivKeySize]byte
|
|
copy(p[:], privKey)
|
|
miniSecretKey, err := schnorrkel.NewMiniSecretKeyFromRaw(p)
|
|
if err != nil {
|
|
return []byte{}, err
|
|
}
|
|
secretKey := miniSecretKey.ExpandEd25519()
|
|
|
|
signingContext := schnorrkel.NewSigningContext([]byte{}, msg)
|
|
|
|
sig, err := secretKey.Sign(signingContext)
|
|
if err != nil {
|
|
return []byte{}, err
|
|
}
|
|
|
|
sigBytes := sig.Encode()
|
|
return sigBytes[:], nil
|
|
}
|
|
|
|
// PubKey gets the corresponding public key from the private key.
|
|
func (privKey PrivKey) PubKey() crypto.PubKey {
|
|
var p [PrivKeySize]byte
|
|
copy(p[:], privKey)
|
|
miniSecretKey, err := schnorrkel.NewMiniSecretKeyFromRaw(p)
|
|
if err != nil {
|
|
panic(fmt.Sprintf("Invalid private key: %v", err))
|
|
}
|
|
secretKey := miniSecretKey.ExpandEd25519()
|
|
|
|
pubkey, err := secretKey.Public()
|
|
if err != nil {
|
|
panic(fmt.Sprintf("Could not generate public key: %v", err))
|
|
}
|
|
key := pubkey.Encode()
|
|
return PubKey(key[:])
|
|
}
|
|
|
|
// Equals - you probably don't need to use this.
|
|
// Runs in constant time based on length of the keys.
|
|
func (privKey PrivKey) Equals(other crypto.PrivKey) bool {
|
|
if otherEd, ok := other.(PrivKey); ok {
|
|
return subtle.ConstantTimeCompare(privKey[:], otherEd[:]) == 1
|
|
}
|
|
return false
|
|
}
|
|
|
|
func (privKey PrivKey) Type() string {
|
|
return keyType
|
|
}
|
|
|
|
// GenPrivKey generates a new sr25519 private key.
|
|
// It uses OS randomness in conjunction with the current global random seed
|
|
// in tendermint/libs/common to generate the private key.
|
|
func GenPrivKey() PrivKey {
|
|
return genPrivKey(crypto.CReader())
|
|
}
|
|
|
|
// genPrivKey generates a new sr25519 private key using the provided reader.
|
|
func genPrivKey(rand io.Reader) PrivKey {
|
|
var seed [64]byte
|
|
|
|
out := make([]byte, 64)
|
|
_, err := io.ReadFull(rand, out)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
copy(seed[:], out)
|
|
|
|
key := schnorrkel.NewMiniSecretKey(seed).ExpandEd25519().Encode()
|
|
return key[:]
|
|
}
|
|
|
|
// GenPrivKeyFromSecret hashes the secret with SHA2, and uses
|
|
// that 32 byte output to create the private key.
|
|
// NOTE: secret should be the output of a KDF like bcrypt,
|
|
// if it's derived from user input.
|
|
func GenPrivKeyFromSecret(secret []byte) PrivKey {
|
|
seed := crypto.Sha256(secret) // Not Ripemd160 because we want 32 bytes.
|
|
var bz [PrivKeySize]byte
|
|
copy(bz[:], seed)
|
|
privKey, _ := schnorrkel.NewMiniSecretKeyFromRaw(bz)
|
|
key := privKey.ExpandEd25519().Encode()
|
|
return key[:]
|
|
}
|