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package quic
import (
"fmt"
"github.com/quic-go/quic-go/internal/protocol"
"github.com/quic-go/quic-go/internal/qerr"
"github.com/quic-go/quic-go/internal/wire"
)
type cryptoStream struct {
queue frameSorter
highestOffset protocol.ByteCount
finished bool
writeOffset protocol.ByteCount
writeBuf []byte
}
func newCryptoStream() *cryptoStream {
return &cryptoStream{queue: *newFrameSorter()}
}
func (s *cryptoStream) HandleCryptoFrame(f *wire.CryptoFrame) error {
highestOffset := f.Offset + protocol.ByteCount(len(f.Data))
if maxOffset := highestOffset; maxOffset > protocol.MaxCryptoStreamOffset {
return &qerr.TransportError{
ErrorCode: qerr.CryptoBufferExceeded,
ErrorMessage: fmt.Sprintf("received invalid offset %d on crypto stream, maximum allowed %d", maxOffset, protocol.MaxCryptoStreamOffset),
}
}
if s.finished {
if highestOffset > s.highestOffset {
// reject crypto data received after this stream was already finished
return &qerr.TransportError{
ErrorCode: qerr.ProtocolViolation,
ErrorMessage: "received crypto data after change of encryption level",
}
}
// ignore data with a smaller offset than the highest received
// could e.g. be a retransmission
return nil
}
s.highestOffset = max(s.highestOffset, highestOffset)
return s.queue.Push(f.Data, f.Offset, nil)
}
// GetCryptoData retrieves data that was received in CRYPTO frames
func (s *cryptoStream) GetCryptoData() []byte {
_, data, _ := s.queue.Pop()
return data
}
func (s *cryptoStream) Finish() error {
if s.queue.HasMoreData() {
return &qerr.TransportError{
ErrorCode: qerr.ProtocolViolation,
ErrorMessage: "encryption level changed, but crypto stream has more data to read",
}
}
s.finished = true
return nil
}
// Writes writes data that should be sent out in CRYPTO frames
func (s *cryptoStream) Write(p []byte) (int, error) {
s.writeBuf = append(s.writeBuf, p...)
return len(p), nil
}
func (s *cryptoStream) HasData() bool {
return len(s.writeBuf) > 0
}
func (s *cryptoStream) PopCryptoFrame(maxLen protocol.ByteCount) *wire.CryptoFrame {
f := &wire.CryptoFrame{Offset: s.writeOffset}
n := min(f.MaxDataLen(maxLen), protocol.ByteCount(len(s.writeBuf)))
f.Data = s.writeBuf[:n]
s.writeBuf = s.writeBuf[n:]
s.writeOffset += n
return f
}
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