[adbwifi] Add A_STLS command.
This command will be sent by adbd to notify the client that the
connection will be over TLS.
When client connects, it will send the CNXN packet, as usual. If the
server connection has TLS enabled, it will send the A_STLS packet
(regardless of whether auth is required). At this point, the client's
only valid response is to send a A_STLS packet. Once both sides have
exchanged the A_STLS packet, both will start the TLS handshake.
If auth is required, then the client will receive a CertificateRequest
with a list of known public keys (SHA256 hash) that it can use in its
certificate. Otherwise, the list will be empty and the client can assume
that either any key will work, or none will work.
If the handshake was successful, the server will send the CNXN packet
and the usual adb protocol is resumed over TLS. If the handshake failed,
both sides will disconnect, as there's no point to retry because the
server's known keys have already been communicated.
Bug: 111434128
Test: WIP; will add to adb_test.py/adb_device.py.
Enable wireless debugging in the Settings, then 'adb connect
<ip>:<port>'. Connection should succeed if key is in keystore. Used
wireshark to check for packet encryption.
Change-Id: I3d60647491c6c6b92297e4f628707a6457fa9420
diff --git a/adb/adb.cpp b/adb/adb.cpp
index 460ddde..554a754 100644
--- a/adb/adb.cpp
+++ b/adb/adb.cpp
@@ -52,6 +52,7 @@
#include "adb_listeners.h"
#include "adb_unique_fd.h"
#include "adb_utils.h"
+#include "adb_wifi.h"
#include "sysdeps/chrono.h"
#include "transport.h"
@@ -140,6 +141,9 @@
case A_CLSE: tag = "CLSE"; break;
case A_WRTE: tag = "WRTE"; break;
case A_AUTH: tag = "AUTH"; break;
+ case A_STLS:
+ tag = "ATLS";
+ break;
default: tag = "????"; break;
}
@@ -209,6 +213,15 @@
android::base::Join(connection_properties, ';').c_str());
}
+void send_tls_request(atransport* t) {
+ D("Calling send_tls_request");
+ apacket* p = get_apacket();
+ p->msg.command = A_STLS;
+ p->msg.arg0 = A_STLS_VERSION;
+ p->msg.data_length = 0;
+ send_packet(p, t);
+}
+
void send_connect(atransport* t) {
D("Calling send_connect");
apacket* cp = get_apacket();
@@ -299,7 +312,12 @@
#if ADB_HOST
handle_online(t);
#else
- if (!auth_required) {
+ if (t->use_tls) {
+ // We still handshake in TLS mode. If auth_required is disabled,
+ // we'll just not verify the client's certificate. This should be the
+ // first packet the client receives to indicate the new protocol.
+ send_tls_request(t);
+ } else if (!auth_required) {
LOG(INFO) << "authentication not required";
handle_online(t);
send_connect(t);
@@ -324,8 +342,21 @@
case A_CNXN: // CONNECT(version, maxdata, "system-id-string")
handle_new_connection(t, p);
break;
+ case A_STLS: // TLS(version, "")
+ t->use_tls = true;
+#if ADB_HOST
+ send_tls_request(t);
+ adb_auth_tls_handshake(t);
+#else
+ adbd_auth_tls_handshake(t);
+#endif
+ break;
case A_AUTH:
+ // All AUTH commands are ignored in TLS mode
+ if (t->use_tls) {
+ break;
+ }
switch (p->msg.arg0) {
#if ADB_HOST
case ADB_AUTH_TOKEN: