move the Public Reset to the wire package

internal/wire/public_reset.go

@@ -0,0 +1,65 @@
+package wire
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+
+	"github.com/lucas-clemente/quic-go/handshake"
+	"github.com/lucas-clemente/quic-go/internal/utils"
+	"github.com/lucas-clemente/quic-go/protocol"
+)
+
+// A PublicReset is a PUBLIC_RESET
+type PublicReset struct {
+	RejectedPacketNumber protocol.PacketNumber
+	Nonce                uint64
+}
+
+// WritePublicReset writes a Public Reset
+func WritePublicReset(connectionID protocol.ConnectionID, rejectedPacketNumber protocol.PacketNumber, nonceProof uint64) []byte {
+	b := &bytes.Buffer{}
+	b.WriteByte(0x0a)
+	utils.LittleEndian.WriteUint64(b, uint64(connectionID))
+	utils.LittleEndian.WriteUint32(b, uint32(handshake.TagPRST))
+	utils.LittleEndian.WriteUint32(b, 2)
+	utils.LittleEndian.WriteUint32(b, uint32(handshake.TagRNON))
+	utils.LittleEndian.WriteUint32(b, 8)
+	utils.LittleEndian.WriteUint32(b, uint32(handshake.TagRSEQ))
+	utils.LittleEndian.WriteUint32(b, 16)
+	utils.LittleEndian.WriteUint64(b, nonceProof)
+	utils.LittleEndian.WriteUint64(b, uint64(rejectedPacketNumber))
+	return b.Bytes()
+}
+
+// ParsePublicReset parses a Public Reset
+func ParsePublicReset(r *bytes.Reader) (*PublicReset, error) {
+	pr := PublicReset{}
+	msg, err := handshake.ParseHandshakeMessage(r)
+	if err != nil {
+		return nil, err
+	}
+	if msg.Tag != handshake.TagPRST {
+		return nil, errors.New("wrong public reset tag")
+	}
+
+	rseq, ok := msg.Data[handshake.TagRSEQ]
+	if !ok {
+		return nil, errors.New("RSEQ missing")
+	}
+	if len(rseq) != 8 {
+		return nil, errors.New("invalid RSEQ tag")
+	}
+	pr.RejectedPacketNumber = protocol.PacketNumber(binary.LittleEndian.Uint64(rseq))
+
+	rnon, ok := msg.Data[handshake.TagRNON]
+	if !ok {
+		return nil, errors.New("RNON missing")
+	}
+	if len(rnon) != 8 {
+		return nil, errors.New("invalid RNON tag")
+	}
+	pr.Nonce = binary.LittleEndian.Uint64(rnon)
+
+	return &pr, nil
+}