Files
quic-go/handshake/crypto_setup.go

85 lines
2.3 KiB
Go

package handshake
import (
"bytes"
"errors"
"io"
"github.com/lucas-clemente/quic-go/crypto"
"github.com/lucas-clemente/quic-go/protocol"
)
// The CryptoSetup handles all things crypto for the Session
type CryptoSetup struct {
connID protocol.ConnectionID
version protocol.VersionNumber
aead crypto.AEAD
scfg *ServerConfig
}
// NewCryptoSetup creates a new CryptoSetup instance
func NewCryptoSetup(connID protocol.ConnectionID, version protocol.VersionNumber, scfg *ServerConfig) *CryptoSetup {
return &CryptoSetup{
connID: connID,
version: version,
aead: &crypto.NullAEAD{},
scfg: scfg,
}
}
// Open a message
func (h *CryptoSetup) Open(packetNumber protocol.PacketNumber, associatedData []byte, ciphertext io.Reader) (*bytes.Reader, error) {
return h.aead.Open(packetNumber, associatedData, ciphertext)
}
// Seal a messageTag
func (h *CryptoSetup) Seal(packetNumber protocol.PacketNumber, b *bytes.Buffer, associatedData []byte, plaintext []byte) {
h.aead.Seal(packetNumber, b, associatedData, plaintext)
}
// HandleCryptoMessage handles the crypto handshake and returns the answer
func (h *CryptoSetup) HandleCryptoMessage(data []byte) ([]byte, error) {
messageTag, cryptoData, err := ParseHandshakeMessage(data)
if err != nil {
return nil, err
}
if messageTag != TagCHLO {
return nil, errors.New("Session: expected CHLO")
}
if scid, ok := cryptoData[TagSCID]; ok && bytes.Equal(h.scfg.ID, scid) {
// We have a CHLO matching our server config, we can continue with the 0-RTT handshake
var sharedSecret []byte
sharedSecret, err = h.scfg.kex.CalculateSharedKey(cryptoData[TagPUBS])
if err != nil {
return nil, err
}
h.aead, err = crypto.DeriveKeysChacha20(sharedSecret, cryptoData[TagNONC], h.connID, data, h.scfg.Get(), h.scfg.kd.GetCertUncompressed())
if err != nil {
return nil, err
}
// TODO: Send SHLO
return nil, nil
}
// We have an inacholate or non-matching CHLO, we now send a rejection
var chloOrNil []byte
if h.version > protocol.VersionNumber(30) {
chloOrNil = data
}
proof, err := h.scfg.Sign(chloOrNil)
if err != nil {
return nil, err
}
var serverReply bytes.Buffer
WriteHandshakeMessage(&serverReply, TagREJ, map[Tag][]byte{
TagSCFG: h.scfg.Get(),
TagCERT: h.scfg.GetCertCompressed(),
TagPROF: proof,
})
return serverReply.Bytes(), nil
}