AZ-X/quiz-CECPQ2.md

## quiz-CECPQ2.md

      
    Raw
  

              quiz-CECPQ2.md
            
          
    quiz

insert

==>
const (
CurveCECPQ2 CurveID = 16696
)
type cecpq2CurveParameters struct {
privateKey     []byte
publicKey      []byte
hrssPrivateKey hrss.PrivateKey
}
func (p *cecpq2CurveParameters) CurveID() CurveID {
return CurveCECPQ2
}
func (p *cecpq2CurveParameters) PublicKey() []byte {
return p.publicKey[:]
}
func (p *cecpq2CurveParameters) SharedKey(peerPublicKey []byte) []byte {
if len(peerPublicKey) != curve25519.ScalarSize+hrss.CiphertextSize {
return nil
}
sharedKey, err := curve25519.X25519(p.privateKey, peerPublicKey[:curve25519.ScalarSize])
if err != nil {
return nil
}
hrssShared, ok := p.hrssPrivateKey.Decap(peerPublicKey[curve25519.ScalarSize:])
if !ok {
	return nil
}

return append(sharedKey, hrssShared...)

}
find the section in the 'same file' & insert

==>
"crypto/tls/hrss"
==>
if curveID == CurveCECPQ2 {
	privateKey := make([]byte, curve25519.ScalarSize)
	if _, err := io.ReadFull(rand, privateKey); err != nil {
		return nil, err
	}
	publicKey, err := curve25519.X25519(privateKey, curve25519.Basepoint)
	hrssPrivateKey := hrss.GenerateKey(rand)
	hrssPublic := hrssPrivateKey.PublicKey.Marshal()
	publicKey = append(publicKey, hrssPublic...)
	if err != nil {
		return nil, err
	}
	return &cecpq2CurveParameters{privateKey: privateKey, publicKey: publicKey, hrssPrivateKey: hrssPrivateKey,}, nil
}

create (borrow it from boring and never return it back)

==>
hrss.go
find & replace

curveID != X25519
==>
curveID != X25519 && curveID != CurveCECPQ2
handle general selection of curve group for TLS1.3

==>
out of scope