r1

go/lib/infra/modules/segfetcher/fetcher.go

@@ -16,6 +16,7 @@ package segfetcher
 
 import (
 	"context"
+	"net"
 	"time"
 
 	"github.com/scionproto/scion/go/lib/addr"
@@ -49,6 +50,10 @@ type FetcherConfig struct {
 	Validator Validator
 	// Splitter is used to split requests.
 	Splitter Splitter
+	// CryptoLookupAtLocalCS indicates whether crypto to verify path material
+	// should be fetched from the local CS or from the sender of the path
+	// material.
+	CryptoLookupAtLocalCS bool
 }
 
 // New creates a new fetcher from the configuration.
@@ -62,24 +67,26 @@ func (cfg FetcherConfig) New() *Fetcher {
 			Verifier: &SegVerifier{Verifier: cfg.VerificationFactory.NewVerifier()},
 			Storage:  &DefaultStorage{PathDB: cfg.PathDB, RevCache: cfg.RevCache},
 		},
-		PathDB:        cfg.PathDB,
-		QueryInterval: cfg.QueryInterval,
+		PathDB:                cfg.PathDB,
+		QueryInterval:         cfg.QueryInterval,
+		CryptoLookupAtLocalCS: cfg.CryptoLookupAtLocalCS,
 	}
 }
 
 // Fetcher fetches, verifies and stores segments for a given path request.
 type Fetcher struct {
-	Validator     Validator
-	Splitter      Splitter
-	Resolver      Resolver
-	Requester     Requester
-	ReplyHandler  ReplyHandler
-	PathDB        pathdb.PathDB
-	QueryInterval time.Duration
+	Validator             Validator
+	Splitter              Splitter
+	Resolver              Resolver
+	Requester             Requester
+	ReplyHandler          ReplyHandler
+	PathDB                pathdb.PathDB
+	QueryInterval         time.Duration
+	CryptoLookupAtLocalCS bool
 }
 
 // FetchSegs fetches the required segments to build a path between src and dst
-// of the request. Firs the request is validated and then depending on the
+// of the request. First the request is validated and then depending on the
 // cache the segments are fetched from the remote server.
 func (f *Fetcher) FetchSegs(ctx context.Context, req Request) (Segments, error) {
 	if f.Validator != nil {
@@ -126,7 +133,7 @@ func (f *Fetcher) waitOnProcessed(ctx context.Context, replies <-chan ReplyOrErr
 		if reply.Reply == nil || reply.Reply.Recs == nil {
 			continue
 		}
-		r := f.ReplyHandler.Handle(ctx, reply.Reply, reply.Peer, nil)
+		r := f.ReplyHandler.Handle(ctx, reply.Reply, f.verifyServer(reply), nil)
 		select {
 		case <-r.FullReplyProcessed():
 			if err := r.Err(); err != nil {
@@ -143,3 +150,10 @@ func (f *Fetcher) waitOnProcessed(ctx context.Context, replies <-chan ReplyOrErr
 	}
 	return nil
 }
+
+func (f *Fetcher) verifyServer(reply ReplyOrErr) net.Addr {
+	if f.CryptoLookupAtLocalCS {
+		return nil
+	}
+	return reply.Peer
+}

go/lib/infra/modules/segfetcher/fetcher_test.go

@@ -114,8 +114,8 @@ func TestFetcher(t *testing.T) {
 			ErrorAssertion: require.NoError,
 			ExpectedSegs:   segfetcher.Segments{Up: seg.Segments{tg.seg130_111}},
 		},
-		// XXX(lukedirtwalker): testing the full loop is quite involved, not
-		// sure if it would be worth it.
+		// XXX(lukedirtwalker): testing the full loop is quite involved, and is
+		// therefore currently omitted.
 	}
 	for name, test := range tests {
 		t.Run(name, func(t *testing.T) {