make quic-go build with both Go 1.13 and 1.14

internal/handshake/go_1-14.go

@@ -0,0 +1,82 @@
+// +build go1.14
+
+package handshake
+
+import (
+	"crypto/tls"
+	"net"
+	"unsafe"
+
+	"github.com/marten-seemann/qtls"
+)
+
+func init() {
+	if !structsEqual(&tls.ClientHelloInfo{}, &clientHelloInfo{}) {
+		panic("clientHelloInfo not compatible with tls.ClientHelloInfo")
+	}
+	if !structsEqual(&qtls.ClientHelloInfo{}, &qtlsClientHelloInfo{}) {
+		panic("qtlsClientHelloInfo not compatible with qtls.ClientHelloInfo")
+	}
+}
+
+func cipherSuiteName(id uint16) string { return qtls.CipherSuiteName(id) }
+
+type clientHelloInfo struct {
+	CipherSuites      []uint16
+	ServerName        string
+	SupportedCurves   []tls.CurveID
+	SupportedPoints   []uint8
+	SignatureSchemes  []tls.SignatureScheme
+	SupportedProtos   []string
+	SupportedVersions []uint16
+	Conn              net.Conn
+
+	config *tls.Config
+}
+
+type qtlsClientHelloInfo struct {
+	CipherSuites      []uint16
+	ServerName        string
+	SupportedCurves   []tls.CurveID
+	SupportedPoints   []uint8
+	SignatureSchemes  []tls.SignatureScheme
+	SupportedProtos   []string
+	SupportedVersions []uint16
+	Conn              net.Conn
+
+	config *qtls.Config
+}
+
+func toTLSClientHelloInfo(chi *qtls.ClientHelloInfo) *tls.ClientHelloInfo {
+	if chi == nil {
+		return nil
+	}
+	qtlsCHI := (*qtlsClientHelloInfo)(unsafe.Pointer(chi))
+	var config *tls.Config
+	if qtlsCHI.config != nil {
+		config = qtlsConfigToTLSConfig((*qtls.Config)(unsafe.Pointer(qtlsCHI.config)))
+	}
+	return (*tls.ClientHelloInfo)(unsafe.Pointer(&clientHelloInfo{
+		CipherSuites:      chi.CipherSuites,
+		ServerName:        chi.ServerName,
+		SupportedCurves:   chi.SupportedCurves,
+		SupportedPoints:   chi.SupportedPoints,
+		SignatureSchemes:  chi.SignatureSchemes,
+		SupportedProtos:   chi.SupportedProtos,
+		SupportedVersions: chi.SupportedVersions,
+		Conn:              chi.Conn,
+		config:            config,
+	}))
+}
+
+// qtlsConfigToTLSConfig is used to transform a qtls.Config to a tls.Config.
+// It is used to create the tls.Config in the ClientHelloInfo.
+// It doesn't copy all values, but only those used by ClientHelloInfo.SupportsCertificate.
+func qtlsConfigToTLSConfig(config *qtls.Config) *tls.Config {
+	return &tls.Config{
+		MinVersion:       config.MinVersion,
+		MaxVersion:       config.MaxVersion,
+		CipherSuites:     config.CipherSuites,
+		CurvePreferences: config.CurvePreferences,
+	}
+}