ceremonyclient/go-libp2p/core/crypto/ed448.go

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2023-08-21 03:50:38 +00:00
package crypto
import (
"bytes"
"crypto/subtle"
"errors"
"fmt"
"io"
pb "github.com/libp2p/go-libp2p/core/crypto/pb"
"github.com/libp2p/go-libp2p/core/internal/catch"
"github.com/cloudflare/circl/sign/ed448"
)
// Ed448PrivateKey is an ed448 private key.
type Ed448PrivateKey struct {
k ed448.PrivateKey
}
// Ed448PublicKey is an ed448 public key.
type Ed448PublicKey struct {
k ed448.PublicKey
}
// GenerateEd448Key generates a new ed448 private and public key pair.
func GenerateEd448Key(src io.Reader) (PrivKey, PubKey, error) {
pub, priv, err := ed448.GenerateKey(src)
if err != nil {
return nil, nil, err
}
return &Ed448PrivateKey{
k: priv,
},
&Ed448PublicKey{
k: pub,
},
nil
}
// Type of the private key (Ed448).
func (k *Ed448PrivateKey) Type() pb.KeyType {
return pb.KeyType_Ed448
}
// Raw private key bytes.
func (k *Ed448PrivateKey) Raw() ([]byte, error) {
// The Ed448 private key contains two 57-bytes curve points, the private
// key and the public key.
// It makes it more efficient to get the public key without re-computing an
// elliptic curve multiplication.
buf := make([]byte, len(k.k))
copy(buf, k.k)
return buf, nil
}
func (k *Ed448PrivateKey) pubKeyBytes() []byte {
return k.k[ed448.PrivateKeySize-ed448.PublicKeySize:]
}
// Equals compares two ed448 private keys.
func (k *Ed448PrivateKey) Equals(o Key) bool {
edk, ok := o.(*Ed448PrivateKey)
if !ok {
return basicEquals(k, o)
}
return subtle.ConstantTimeCompare(k.k, edk.k) == 1
}
// GetPublic returns an ed448 public key from a private key.
func (k *Ed448PrivateKey) GetPublic() PubKey {
return &Ed448PublicKey{k: k.pubKeyBytes()}
}
// Sign returns a signature from an input message.
func (k *Ed448PrivateKey) Sign(msg []byte) (res []byte, err error) {
defer func() { catch.HandlePanic(recover(), &err, "ed448 signing") }()
return ed448.Sign(k.k, msg, ""), nil
}
// Type of the public key (Ed448).
func (k *Ed448PublicKey) Type() pb.KeyType {
return pb.KeyType_Ed448
}
// Raw public key bytes.
func (k *Ed448PublicKey) Raw() ([]byte, error) {
return k.k, nil
}
// Equals compares two ed448 public keys.
func (k *Ed448PublicKey) Equals(o Key) bool {
edk, ok := o.(*Ed448PublicKey)
if !ok {
return basicEquals(k, o)
}
return bytes.Equal(k.k, edk.k)
}
// Verify checks a signature against the input data.
func (k *Ed448PublicKey) Verify(data []byte, sig []byte) (success bool, err error) {
defer func() {
catch.HandlePanic(recover(), &err, "ed448 signature verification")
// To be safe.
if err != nil {
success = false
}
}()
return ed448.Verify(k.k, data, sig, ""), nil
}
// UnmarshalEd448PublicKey returns a public key from input bytes.
func UnmarshalEd448PublicKey(data []byte) (PubKey, error) {
if len(data) != 57 {
return nil, errors.New("expect ed448 public key data size to be 57")
}
return &Ed448PublicKey{
k: ed448.PublicKey(data),
}, nil
}
// UnmarshalEd448PrivateKey returns a private key from input bytes.
func UnmarshalEd448PrivateKey(data []byte) (PrivKey, error) {
switch len(data) {
case ed448.PrivateKeySize + ed448.PublicKeySize:
// Remove the redundant public key. See issue #36.
redundantPk := data[ed448.PrivateKeySize:]
pk := data[ed448.PrivateKeySize-ed448.PublicKeySize : ed448.PrivateKeySize]
if subtle.ConstantTimeCompare(pk, redundantPk) == 0 {
return nil, errors.New("expected redundant ed448 public key to be redundant")
}
// No point in storing the extra data.
newKey := make([]byte, ed448.PrivateKeySize)
copy(newKey, data[:ed448.PrivateKeySize])
data = newKey
case ed448.PrivateKeySize:
default:
return nil, fmt.Errorf(
"expected ed448 data size to be %d or %d, got %d",
ed448.PrivateKeySize,
ed448.PrivateKeySize+ed448.PublicKeySize,
len(data),
)
}
return &Ed448PrivateKey{
k: ed448.PrivateKey(data),
}, nil
}