use go 1.12

Signed-off-by: hongming <talonwan@yunify.com>

vendor/github.com/lucas-clemente/quic-go/internal/crypto/key_derivation.go

@@ -0,0 +1,49 @@
+package crypto
+
+import (
+	"github.com/bifurcation/mint"
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+)
+
+const (
+	clientExporterLabel = "EXPORTER-QUIC client 1rtt"
+	serverExporterLabel = "EXPORTER-QUIC server 1rtt"
+)
+
+// A TLSExporter gets the negotiated ciphersuite and computes exporter
+type TLSExporter interface {
+	ConnectionState() mint.ConnectionState
+	ComputeExporter(label string, context []byte, keyLength int) ([]byte, error)
+}
+
+// DeriveAESKeys derives the AES keys and creates a matching AES-GCM AEAD instance
+func DeriveAESKeys(tls TLSExporter, pers protocol.Perspective) (AEAD, error) {
+	var myLabel, otherLabel string
+	if pers == protocol.PerspectiveClient {
+		myLabel = clientExporterLabel
+		otherLabel = serverExporterLabel
+	} else {
+		myLabel = serverExporterLabel
+		otherLabel = clientExporterLabel
+	}
+	myKey, myIV, err := computeKeyAndIV(tls, myLabel)
+	if err != nil {
+		return nil, err
+	}
+	otherKey, otherIV, err := computeKeyAndIV(tls, otherLabel)
+	if err != nil {
+		return nil, err
+	}
+	return NewAEADAESGCM(otherKey, myKey, otherIV, myIV)
+}
+
+func computeKeyAndIV(tls TLSExporter, label string) (key, iv []byte, err error) {
+	cs := tls.ConnectionState().CipherSuite
+	secret, err := tls.ComputeExporter(label, nil, cs.Hash.Size())
+	if err != nil {
+		return nil, nil, err
+	}
+	key = qhkdfExpand(secret, "key", cs.KeyLen)
+	iv = qhkdfExpand(secret, "iv", cs.IvLen)
+	return key, iv, nil
+}