implement public reset packet writing

handshake/tags.go

@@ -71,4 +71,11 @@ const (
 
 	// TagSHLO is the server hello
 	TagSHLO Tag = 'S' + 'H'<<8 + 'L'<<16 + 'O'<<24
+
+	// TagPRST is the public reset tag
+	TagPRST Tag = 'P' + 'R'<<8 + 'S'<<16 + 'T'<<24
+	// TagRSEQ is the public reset rejected packet number
+	TagRSEQ Tag = 'R' + 'S'<<8 + 'E'<<16 + 'Q'<<24
+	// TagRNON is the public reset nonce
+	TagRNON Tag = 'R' + 'N'<<8 + 'O'<<16 + 'N'<<24
 )

public_reset.go

@@ -0,0 +1,28 @@
+package quic
+
+import (
+	"bytes"
+
+	"github.com/lucas-clemente/quic-go/handshake"
+	"github.com/lucas-clemente/quic-go/protocol"
+	"github.com/lucas-clemente/quic-go/utils"
+)
+
+type publicResetPacket struct {
+	connectionID         protocol.ConnectionID
+	rejectedPacketNumber protocol.PacketNumber
+	nonceProof           uint64
+}
+
+func (p *publicResetPacket) Write(b *bytes.Buffer) {
+	b.WriteByte(0x0a)
+	utils.WriteUint64(b, uint64(p.connectionID))
+	utils.WriteUint32(b, uint32(handshake.TagPRST))
+	utils.WriteUint32(b, 2)
+	utils.WriteUint32(b, uint32(handshake.TagRNON))
+	utils.WriteUint32(b, 8)
+	utils.WriteUint32(b, uint32(handshake.TagRSEQ))
+	utils.WriteUint32(b, 16)
+	utils.WriteUint64(b, p.nonceProof)
+	utils.WriteUint64(b, uint64(p.rejectedPacketNumber))
+}

public_reset_test.go

@@ -0,0 +1,34 @@
+package quic
+
+import (
+	"bytes"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("public reset", func() {
+	Context("writing", func() {
+		It("writes public reset packets", func() {
+			packet := &publicResetPacket{
+				connectionID:         0xdeadbeef,
+				rejectedPacketNumber: 0x8badf00d,
+				nonceProof:           0xdecafbad,
+			}
+			b := &bytes.Buffer{}
+			packet.Write(b)
+			Expect(b.Bytes()).To(Equal([]byte{
+				0x0a,
+				0xef, 0xbe, 0xad, 0xde, 0x00, 0x00, 0x00, 0x00,
+				'P', 'R', 'S', 'T',
+				0x02, 0x00, 0x00, 0x00,
+				'R', 'N', 'O', 'N',
+				0x08, 0x00, 0x00, 0x00,
+				'R', 'S', 'E', 'Q',
+				0x10, 0x00, 0x00, 0x00,
+				0xad, 0xfb, 0xca, 0xde, 0x0, 0x0, 0x0, 0x0,
+				0x0d, 0xf0, 0xad, 0x8b, 0x0, 0x0, 0x0, 0x0,
+			}))
+		})
+	})
+})