build(deps): bump github.com/quic-go/quic-go from 0.40.1 to 0.42.0 (#289)

* build(deps): bump github.com/quic-go/quic-go from 0.40.1 to 0.42.0

Bumps [github.com/quic-go/quic-go](https://github.com/quic-go/quic-go) from 0.40.1 to 0.42.0.
- [Release notes](https://github.com/quic-go/quic-go/releases)
- [Changelog](https://github.com/quic-go/quic-go/blob/master/Changelog.md)
- [Commits](https://github.com/quic-go/quic-go/compare/v0.40.1...v0.42.0)

---
updated-dependencies:
- dependency-name: github.com/quic-go/quic-go
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

* update: remove dependency of quic-go

We now vendor the quicvarint submodule from quic-go for a minimal dependency tree.

This also updates the minimal Go version requirement to Go 1.21, given uTLS promised to support 2 most recent minor versions of Go.

Signed-off-by: Gaukas Wang <i@gaukas.wang>

---------

Signed-off-by: dependabot[bot] <support@github.com>
Signed-off-by: Gaukas Wang <i@gaukas.wang>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Gaukas Wang <i@gaukas.wang>

internal/quicvarint/protocol/protocol.go

@@ -0,0 +1,157 @@
+// Copyright 2024 The quic-go Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file of
+// the quic-go repository.
+
+package protocol
+
+import (
+	"fmt"
+	"time"
+)
+
+// The PacketType is the Long Header Type
+type PacketType uint8
+
+const (
+	// PacketTypeInitial is the packet type of an Initial packet
+	PacketTypeInitial PacketType = 1 + iota
+	// PacketTypeRetry is the packet type of a Retry packet
+	PacketTypeRetry
+	// PacketTypeHandshake is the packet type of a Handshake packet
+	PacketTypeHandshake
+	// PacketType0RTT is the packet type of a 0-RTT packet
+	PacketType0RTT
+)
+
+func (t PacketType) String() string {
+	switch t {
+	case PacketTypeInitial:
+		return "Initial"
+	case PacketTypeRetry:
+		return "Retry"
+	case PacketTypeHandshake:
+		return "Handshake"
+	case PacketType0RTT:
+		return "0-RTT Protected"
+	default:
+		return fmt.Sprintf("unknown packet type: %d", t)
+	}
+}
+
+type ECN uint8
+
+const (
+	ECNUnsupported ECN = iota
+	ECNNon             // 00
+	ECT1               // 01
+	ECT0               // 10
+	ECNCE              // 11
+)
+
+func ParseECNHeaderBits(bits byte) ECN {
+	switch bits {
+	case 0:
+		return ECNNon
+	case 0b00000010:
+		return ECT0
+	case 0b00000001:
+		return ECT1
+	case 0b00000011:
+		return ECNCE
+	default:
+		panic("invalid ECN bits")
+	}
+}
+
+func (e ECN) ToHeaderBits() byte {
+	//nolint:exhaustive // There are only 4 values.
+	switch e {
+	case ECNNon:
+		return 0
+	case ECT0:
+		return 0b00000010
+	case ECT1:
+		return 0b00000001
+	case ECNCE:
+		return 0b00000011
+	default:
+		panic("ECN unsupported")
+	}
+}
+
+func (e ECN) String() string {
+	switch e {
+	case ECNUnsupported:
+		return "ECN unsupported"
+	case ECNNon:
+		return "Not-ECT"
+	case ECT1:
+		return "ECT(1)"
+	case ECT0:
+		return "ECT(0)"
+	case ECNCE:
+		return "CE"
+	default:
+		return fmt.Sprintf("invalid ECN value: %d", e)
+	}
+}
+
+// A ByteCount in QUIC
+type ByteCount int64
+
+// MaxByteCount is the maximum value of a ByteCount
+const MaxByteCount = ByteCount(1<<62 - 1)
+
+// InvalidByteCount is an invalid byte count
+const InvalidByteCount ByteCount = -1
+
+// A StatelessResetToken is a stateless reset token.
+type StatelessResetToken [16]byte
+
+// MaxPacketBufferSize maximum packet size of any QUIC packet, based on
+// ethernet's max size, minus the IP and UDP headers. IPv6 has a 40 byte header,
+// UDP adds an additional 8 bytes.  This is a total overhead of 48 bytes.
+// Ethernet's max packet size is 1500 bytes,  1500 - 48 = 1452.
+const MaxPacketBufferSize = 1452
+
+// MaxLargePacketBufferSize is used when using GSO
+const MaxLargePacketBufferSize = 20 * 1024
+
+// MinInitialPacketSize is the minimum size an Initial packet is required to have.
+const MinInitialPacketSize = 1200
+
+// MinUnknownVersionPacketSize is the minimum size a packet with an unknown version
+// needs to have in order to trigger a Version Negotiation packet.
+const MinUnknownVersionPacketSize = MinInitialPacketSize
+
+// MinStatelessResetSize is the minimum size of a stateless reset packet that we send
+const MinStatelessResetSize = 1 /* first byte */ + 20 /* max. conn ID length */ + 4 /* max. packet number length */ + 1 /* min. payload length */ + 16 /* token */
+
+// MinConnectionIDLenInitial is the minimum length of the destination connection ID on an Initial packet.
+const MinConnectionIDLenInitial = 8
+
+// DefaultAckDelayExponent is the default ack delay exponent
+const DefaultAckDelayExponent = 3
+
+// DefaultActiveConnectionIDLimit is the default active connection ID limit
+const DefaultActiveConnectionIDLimit = 2
+
+// MaxAckDelayExponent is the maximum ack delay exponent
+const MaxAckDelayExponent = 20
+
+// DefaultMaxAckDelay is the default max_ack_delay
+const DefaultMaxAckDelay = 25 * time.Millisecond
+
+// MaxMaxAckDelay is the maximum max_ack_delay
+const MaxMaxAckDelay = (1<<14 - 1) * time.Millisecond
+
+// MaxConnIDLen is the maximum length of the connection ID
+const MaxConnIDLen = 20
+
+// InvalidPacketLimitAES is the maximum number of packets that we can fail to decrypt when using
+// AEAD_AES_128_GCM or AEAD_AES_265_GCM.
+const InvalidPacketLimitAES = 1 << 52
+
+// InvalidPacketLimitChaCha is the maximum number of packets that we can fail to decrypt when using AEAD_CHACHA20_POLY1305.
+const InvalidPacketLimitChaCha = 1 << 36

internal/quicvarint/varint.go

@@ -0,0 +1,146 @@
+// Copyright 2024 The quic-go Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file of
+// the quic-go repository.
+
+package quicvarint
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/refraction-networking/utls/internal/quicvarint/protocol"
+)
+
+// taken from the QUIC draft
+const (
+	// Min is the minimum value allowed for a QUIC varint.
+	Min = 0
+
+	// Max is the maximum allowed value for a QUIC varint (2^62-1).
+	Max = maxVarInt8
+
+	maxVarInt1 = 63
+	maxVarInt2 = 16383
+	maxVarInt4 = 1073741823
+	maxVarInt8 = 4611686018427387903
+)
+
+// Read reads a number in the QUIC varint format from r.
+func Read(r io.ByteReader) (uint64, error) {
+	firstByte, err := r.ReadByte()
+	if err != nil {
+		return 0, err
+	}
+	// the first two bits of the first byte encode the length
+	len := 1 << ((firstByte & 0xc0) >> 6)
+	b1 := firstByte & (0xff - 0xc0)
+	if len == 1 {
+		return uint64(b1), nil
+	}
+	b2, err := r.ReadByte()
+	if err != nil {
+		return 0, err
+	}
+	if len == 2 {
+		return uint64(b2) + uint64(b1)<<8, nil
+	}
+	b3, err := r.ReadByte()
+	if err != nil {
+		return 0, err
+	}
+	b4, err := r.ReadByte()
+	if err != nil {
+		return 0, err
+	}
+	if len == 4 {
+		return uint64(b4) + uint64(b3)<<8 + uint64(b2)<<16 + uint64(b1)<<24, nil
+	}
+	b5, err := r.ReadByte()
+	if err != nil {
+		return 0, err
+	}
+	b6, err := r.ReadByte()
+	if err != nil {
+		return 0, err
+	}
+	b7, err := r.ReadByte()
+	if err != nil {
+		return 0, err
+	}
+	b8, err := r.ReadByte()
+	if err != nil {
+		return 0, err
+	}
+	return uint64(b8) + uint64(b7)<<8 + uint64(b6)<<16 + uint64(b5)<<24 + uint64(b4)<<32 + uint64(b3)<<40 + uint64(b2)<<48 + uint64(b1)<<56, nil
+}
+
+// Append appends i in the QUIC varint format.
+func Append(b []byte, i uint64) []byte {
+	if i <= maxVarInt1 {
+		return append(b, uint8(i))
+	}
+	if i <= maxVarInt2 {
+		return append(b, []byte{uint8(i>>8) | 0x40, uint8(i)}...)
+	}
+	if i <= maxVarInt4 {
+		return append(b, []byte{uint8(i>>24) | 0x80, uint8(i >> 16), uint8(i >> 8), uint8(i)}...)
+	}
+	if i <= maxVarInt8 {
+		return append(b, []byte{
+			uint8(i>>56) | 0xc0, uint8(i >> 48), uint8(i >> 40), uint8(i >> 32),
+			uint8(i >> 24), uint8(i >> 16), uint8(i >> 8), uint8(i),
+		}...)
+	}
+	panic(fmt.Sprintf("%#x doesn't fit into 62 bits", i))
+}
+
+// AppendWithLen append i in the QUIC varint format with the desired length.
+func AppendWithLen(b []byte, i uint64, length protocol.ByteCount) []byte {
+	if length != 1 && length != 2 && length != 4 && length != 8 {
+		panic("invalid varint length")
+	}
+	l := Len(i)
+	if l == length {
+		return Append(b, i)
+	}
+	if l > length {
+		panic(fmt.Sprintf("cannot encode %d in %d bytes", i, length))
+	}
+	if length == 2 {
+		b = append(b, 0b01000000)
+	} else if length == 4 {
+		b = append(b, 0b10000000)
+	} else if length == 8 {
+		b = append(b, 0b11000000)
+	}
+	for j := protocol.ByteCount(1); j < length-l; j++ {
+		b = append(b, 0)
+	}
+	for j := protocol.ByteCount(0); j < l; j++ {
+		b = append(b, uint8(i>>(8*(l-1-j))))
+	}
+	return b
+}
+
+// Len determines the number of bytes that will be needed to write the number i.
+func Len(i uint64) protocol.ByteCount {
+	if i <= maxVarInt1 {
+		return 1
+	}
+	if i <= maxVarInt2 {
+		return 2
+	}
+	if i <= maxVarInt4 {
+		return 4
+	}
+	if i <= maxVarInt8 {
+		return 8
+	}
+	// Don't use a fmt.Sprintf here to format the error message.
+	// The function would then exceed the inlining budget.
+	panic(struct {
+		message string
+		num     uint64
+	}{"value doesn't fit into 62 bits: ", i})
+}