diff --git a/adb/adb.cpp b/adb/adb.cpp
index 3bf281c..76ca19a 100644
--- a/adb/adb.cpp
+++ b/adb/adb.cpp
@@ -365,8 +365,8 @@
         switch (p->msg.arg0) {
 #if ADB_HOST
             case ADB_AUTH_TOKEN:
-                if (t->GetConnectionState() == kCsOffline) {
-                    t->SetConnectionState(kCsUnauthorized);
+                if (t->GetConnectionState() != kCsAuthorizing) {
+                    t->SetConnectionState(kCsAuthorizing);
                 }
                 send_auth_response(p->payload.data(), p->msg.data_length, t);
                 break;
@@ -1103,14 +1103,11 @@
     if (!strcmp(service, "reconnect-offline")) {
         std::string response;
         close_usb_devices([&response](const atransport* transport) {
-            switch (transport->GetConnectionState()) {
-                case kCsOffline:
-                case kCsUnauthorized:
-                    response += "reconnecting " + transport->serial_name() + "\n";
-                    return true;
-                default:
-                    return false;
+            if (!ConnectionStateIsOnline(transport->GetConnectionState())) {
+                response += "reconnecting " + transport->serial_name() + "\n";
+                return true;
             }
+            return false;
         });
         if (!response.empty()) {
             response.resize(response.size() - 1);
diff --git a/adb/adb.h b/adb/adb.h
index 1e58ee1..ede55da 100644
--- a/adb/adb.h
+++ b/adb/adb.h
@@ -95,16 +95,33 @@
 
 enum ConnectionState {
     kCsAny = -1,
-    kCsOffline = 0,
+
+    kCsConnecting = 0,  // Haven't received a response from the device yet.
+    kCsAuthorizing,     // Authorizing with keys from ADB_VENDOR_KEYS.
+    kCsUnauthorized,    // ADB_VENDOR_KEYS exhausted, fell back to user prompt.
+    kCsNoPerm,          // Insufficient permissions to communicate with the device.
+    kCsOffline,
+
     kCsBootloader,
     kCsDevice,
     kCsHost,
     kCsRecovery,
-    kCsNoPerm,  // Insufficient permissions to communicate with the device.
     kCsSideload,
-    kCsUnauthorized,
 };
 
+inline bool ConnectionStateIsOnline(ConnectionState state) {
+    switch (state) {
+        case kCsBootloader:
+        case kCsDevice:
+        case kCsHost:
+        case kCsRecovery:
+        case kCsSideload:
+            return true;
+        default:
+            return false;
+    }
+}
+
 void print_packet(const char* label, apacket* p);
 
 // These use the system (v)fprintf, not the adb prefixed ones defined in sysdeps.h, so they
diff --git a/adb/client/auth.cpp b/adb/client/auth.cpp
index ade2623..0f4dd33 100644
--- a/adb/client/auth.cpp
+++ b/adb/client/auth.cpp
@@ -464,6 +464,7 @@
     std::shared_ptr<RSA> key = t->NextKey();
     if (key == nullptr) {
         // No more private keys to try, send the public key.
+        t->SetConnectionState(kCsUnauthorized);
         send_auth_publickey(t);
         return;
     }
diff --git a/adb/sockets.cpp b/adb/sockets.cpp
index 7bc0165..e567ff4 100644
--- a/adb/sockets.cpp
+++ b/adb/sockets.cpp
@@ -750,7 +750,7 @@
     if (!s->transport) {
         SendFail(s->peer->fd, "device offline (no transport)");
         goto fail;
-    } else if (s->transport->GetConnectionState() == kCsOffline) {
+    } else if (!ConnectionStateIsOnline(s->transport->GetConnectionState())) {
         /* if there's no remote we fail the connection
          ** right here and terminate it
          */
diff --git a/adb/transport.cpp b/adb/transport.cpp
index fa7cc8c..be7f8fe 100644
--- a/adb/transport.cpp
+++ b/adb/transport.cpp
@@ -708,22 +708,41 @@
     }
     lock.unlock();
 
-    // Don't return unauthorized devices; the caller can't do anything with them.
-    if (result && result->GetConnectionState() == kCsUnauthorized && !accept_any_state) {
-        *error_out = "device unauthorized.\n";
-        char* ADB_VENDOR_KEYS = getenv("ADB_VENDOR_KEYS");
-        *error_out += "This adb server's $ADB_VENDOR_KEYS is ";
-        *error_out += ADB_VENDOR_KEYS ? ADB_VENDOR_KEYS : "not set";
-        *error_out += "\n";
-        *error_out += "Try 'adb kill-server' if that seems wrong.\n";
-        *error_out += "Otherwise check for a confirmation dialog on your device.";
-        result = nullptr;
-    }
+    if (result && !accept_any_state) {
+        // The caller requires an active transport.
+        // Make sure that we're actually connected.
+        ConnectionState state = result->GetConnectionState();
+        switch (state) {
+            case kCsConnecting:
+                *error_out = "device still connecting";
+                result = nullptr;
+                break;
 
-    // Don't return offline devices; the caller can't do anything with them.
-    if (result && result->GetConnectionState() == kCsOffline && !accept_any_state) {
-        *error_out = "device offline";
-        result = nullptr;
+            case kCsAuthorizing:
+                *error_out = "device still authorizing";
+                result = nullptr;
+                break;
+
+            case kCsUnauthorized: {
+                *error_out = "device unauthorized.\n";
+                char* ADB_VENDOR_KEYS = getenv("ADB_VENDOR_KEYS");
+                *error_out += "This adb server's $ADB_VENDOR_KEYS is ";
+                *error_out += ADB_VENDOR_KEYS ? ADB_VENDOR_KEYS : "not set";
+                *error_out += "\n";
+                *error_out += "Try 'adb kill-server' if that seems wrong.\n";
+                *error_out += "Otherwise check for a confirmation dialog on your device.";
+                result = nullptr;
+                break;
+            }
+
+            case kCsOffline:
+                *error_out = "device offline";
+                result = nullptr;
+                break;
+
+            default:
+                break;
+        }
     }
 
     if (result) {
@@ -802,6 +821,10 @@
             return "sideload";
         case kCsUnauthorized:
             return "unauthorized";
+        case kCsAuthorizing:
+            return "authorizing";
+        case kCsConnecting:
+            return "connecting";
         default:
             return "unknown";
     }
@@ -1080,7 +1103,7 @@
 
 void register_usb_transport(usb_handle* usb, const char* serial, const char* devpath,
                             unsigned writeable) {
-    atransport* t = new atransport((writeable ? kCsOffline : kCsNoPerm));
+    atransport* t = new atransport((writeable ? kCsConnecting : kCsNoPerm));
 
     D("transport: %p init'ing for usb_handle %p (sn='%s')", t, usb, serial ? serial : "");
     init_usb_transport(t, usb);
diff --git a/adb/transport.h b/adb/transport.h
index ebc186b..e1cbc09 100644
--- a/adb/transport.h
+++ b/adb/transport.h
@@ -198,7 +198,7 @@
     // class in one go is a very large change. Given how bad our testing is,
     // it's better to do this piece by piece.
 
-    atransport(ConnectionState state = kCsOffline)
+    atransport(ConnectionState state = kCsConnecting)
         : id(NextTransportId()),
           connection_state_(state),
           connection_waitable_(std::make_shared<ConnectionWaitable>()),