Files
quic-go/handshake/crypto_setup_client.go

155 lines
3.7 KiB
Go

package handshake
import (
"bytes"
"crypto/rand"
"encoding/binary"
"errors"
"io"
"time"
"github.com/lucas-clemente/quic-go/crypto"
"github.com/lucas-clemente/quic-go/protocol"
"github.com/lucas-clemente/quic-go/qerr"
"github.com/lucas-clemente/quic-go/utils"
)
type cryptoSetupClient struct {
connID protocol.ConnectionID
version protocol.VersionNumber
cryptoStream utils.Stream
serverConfig *serverConfigClient
diversificationNonce []byte
}
var _ crypto.AEAD = &cryptoSetupClient{}
var _ CryptoSetup = &cryptoSetupClient{}
var (
errNoObitForClientNonce = errors.New("No OBIT for client nonce available")
errConflictingDiversificationNonces = errors.New("Received two different diversification nonces")
)
// NewCryptoSetupClient creates a new CryptoSetup instance for a client
func NewCryptoSetupClient(
connID protocol.ConnectionID,
version protocol.VersionNumber,
cryptoStream utils.Stream,
) (CryptoSetup, error) {
return &cryptoSetupClient{
connID: connID,
version: version,
cryptoStream: cryptoStream,
}, nil
}
func (h *cryptoSetupClient) HandleCryptoStream() error {
err := h.sendInchoateCHLO()
if err != nil {
return err
}
for {
var shloData bytes.Buffer
messageTag, cryptoData, err := ParseHandshakeMessage(io.TeeReader(h.cryptoStream, &shloData))
if err != nil {
return qerr.HandshakeFailed
}
if messageTag == TagSHLO {
utils.Debugf("Got SHLO:\n%s", printHandshakeMessage(cryptoData))
} else if messageTag == TagREJ {
utils.Debugf("Got REJ:\n%s", printHandshakeMessage(cryptoData))
if scfg, ok := cryptoData[TagSCFG]; ok {
h.serverConfig, err = parseServerConfig(scfg)
if err != nil {
return err
}
}
} else {
return qerr.InvalidCryptoMessageType
}
}
}
func (h *cryptoSetupClient) Open(dst, src []byte, packetNumber protocol.PacketNumber, associatedData []byte) ([]byte, error) {
return (&crypto.NullAEAD{}).Open(dst, src, packetNumber, associatedData)
}
func (h *cryptoSetupClient) Seal(dst, src []byte, packetNumber protocol.PacketNumber, associatedData []byte) []byte {
return (&crypto.NullAEAD{}).Seal(dst, src, packetNumber, associatedData)
}
func (h *cryptoSetupClient) DiversificationNonce() []byte {
panic("not needed for cryptoSetupClient")
}
func (h *cryptoSetupClient) SetDiversificationNonce(data []byte) error {
if len(h.diversificationNonce) == 0 {
h.diversificationNonce = data
return nil
}
if !bytes.Equal(h.diversificationNonce, data) {
return errConflictingDiversificationNonces
}
return nil
}
func (h *cryptoSetupClient) LockForSealing() {
}
func (h *cryptoSetupClient) UnlockForSealing() {
}
func (h *cryptoSetupClient) HandshakeComplete() bool {
return false
}
func (h *cryptoSetupClient) getInchoateCHLOValues() map[Tag][]byte {
tags := make(map[Tag][]byte)
tags[TagSNI] = []byte("quic.clemente.io") // TODO: use real SNI here
tags[TagPDMD] = []byte("X509")
tags[TagPAD] = bytes.Repeat([]byte("0"), protocol.ClientHelloMinimumSize)
versionTag := make([]byte, 4, 4)
binary.LittleEndian.PutUint32(versionTag, protocol.VersionNumberToTag(h.version))
tags[TagVER] = versionTag
return tags
}
func (h *cryptoSetupClient) sendInchoateCHLO() error {
b := &bytes.Buffer{}
tags := h.getInchoateCHLOValues()
WriteHandshakeMessage(b, TagCHLO, tags)
_, err := h.cryptoStream.Write(b.Bytes())
if err != nil {
return err
}
return nil
}
func (h *cryptoSetupClient) generateClientNonce() ([]byte, error) {
nonce := make([]byte, 32)
binary.BigEndian.PutUint32(nonce, uint32(time.Now().Unix()))
if len(h.serverConfig.obit) != 8 {
return nil, errNoObitForClientNonce
}
copy(nonce[4:12], h.serverConfig.obit)
_, err := rand.Read(nonce[12:])
if err != nil {
return nil, err
}
return nonce, nil
}