fix: sanity check against qtp

gaukas · Jul 20, 2023 · c9bf02c · c9bf02c
1 parent 908c6d6
commit c9bf02c
Show file tree

Hide file tree

Showing 2 changed files with 17 additions and 0 deletions.
diff --git a/quic_clienthello.go b/quic_clienthello.go
@@ -27,6 +27,14 @@ func ParseQUICClientHello(p []byte) (*QUICClientHello, error) {
 		return nil, err
 	}
 
+	if ch.qtp == nil {
+		return nil, ErrNotQUICInitialPacket
+	}
+
+	if ch.qtp.ParseError() != nil {
+		return nil, ch.qtp.ParseError()
+	}
+
 	return &QUICClientHello{ClientHello: *ch}, nil
 }
 

diff --git a/quic_transport_parameters.go b/quic_transport_parameters.go
@@ -6,6 +6,7 @@ import (
 	"encoding/binary"
 	"encoding/hex"
 	"errors"
+	"fmt"
 	"sort"
 
 	"github.com/gaukas/clienthellod/internal/utils"
@@ -58,15 +59,23 @@ func ParseQUICTransportParameters(extData []byte) *QUICTransportParameters {
 	for r.Len() > 0 {
 		paramType, _, qtp.parseError = ReadNextVLI(r)
 		if qtp.parseError != nil {
+			qtp.parseError = fmt.Errorf("failed to read transport parameter type: %w", qtp.parseError)
 			return qtp
 		}
 		paramValLen, _, qtp.parseError = ReadNextVLI(r)
 		if qtp.parseError != nil {
+			qtp.parseError = fmt.Errorf("failed to read transport parameter value length: %w", qtp.parseError)
 			return qtp
 		}
+
+		if paramValLen == 0 {
+			continue // skip empty transport parameter, no need to try to read
+		}
+
 		paramData = make([]byte, paramValLen)
 		n, qtp.parseError = r.Read(paramData)
 		if qtp.parseError != nil {
+			qtp.parseError = fmt.Errorf("failed to read transport parameter value: %w", qtp.parseError)
 			return qtp
 		}
 		if uint64(n) != paramValLen {