Implement backwards-compatible RemoteStore::addToStore()

The SSHStore PR adds this functionality to the daemon, but we have to
handle the case where the Nix daemon is 1.11.

Also, don't require signatures for trusted users. This restores 1.11
behaviour.

Fixes https://github.com/NixOS/hydra/issues/398.

src/libstore/remote-store.cc

@@ -335,7 +335,28 @@ Path RemoteStore::queryPathFromHashPart(const string & hashPart)
 void RemoteStore::addToStore(const ValidPathInfo & info, const ref<std::string> & nar,
     bool repair, bool dontCheckSigs, std::shared_ptr<FSAccessor> accessor)
 {
-    throw Error("RemoteStore::addToStore() not implemented");
+    auto conn(connections->get());
+    conn->to << wopImportPaths;
+
+    StringSink sink;
+    sink << 1 // == path follows
+        ;
+    assert(nar->size() % 8 == 0);
+    sink((unsigned char *) nar->data(), nar->size());
+    sink
+        << exportMagic
+        << info.path
+        << info.references
+        << info.deriver
+        << 0 // == no legacy signature
+        << 0 // == no path follows
+        ;
+
+    StringSource source(*sink.s);
+    conn->processStderr(0, &source);
+
+    auto importedPaths = readStorePaths<PathSet>(*this, conn->from);
+    assert(importedPaths.size() <= 1);
 }
 
 

src/nix-daemon/nix-daemon.cc

@@ -324,7 +324,7 @@ static void performOp(ref<LocalStore> store, bool trusted, unsigned int clientVe
     case wopImportPaths: {
         startWork();
         TunnelSource source(from);
-        Paths paths = store->importPaths(source, 0);
+        Paths paths = store->importPaths(source, 0, trusted);
         stopWork();
         to << paths;
         break;