adb: Add public key authentification
Secure adb using a public key authentication, to allow USB debugging
only from authorized hosts.
When a device is connected to an unauthorized host, the adb daemon sends
the user public key to the device. A popup is shown to ask the user to
allow debugging once or permanantly from the host. The public key is
installed on the device in the later case. Other keys may be installed
at build time.
On the host, the user public/private key pair is automatically generated,
if it does not exist, when the adb daemon starts and is stored in
$HOME/.android/adb_key(.pub) or in $ANDROID_SDK_HOME on windows. If needed,
the ADB_KEYS_PATH env variable may be set to a :-separated (; under
Windows) list of private keys, e.g. company-wide or vendor keys.
On the device, vendors public keys are installed at build time in
/adb_keys. User-installed keys are stored in /data/misc/adb/adb_keys.
ADB Protocol change:
If the device needs to authenticate the host, it replies to CNXN
packets with an AUTH packet. The AUTH packet payload is a random token.
The host signs the token with one of its private keys and sends an AUTH(0)
packet. If the signature verification succeeds, the device replies with
a CNXN packet. Otherwise, it sends a new AUTH packet with a new token so
that the host can retry with another private key. Once the host has tried
all its keys, it can send an AUTH(1) packet with a public key as
payload. adbd then sends the public key to the framework (if it has been
started) for confirmation.
Change-Id: I4e84d7621da956f66ff657245901bdaefead8395
diff --git a/adb/adb_auth.h b/adb/adb_auth.h
new file mode 100644
index 0000000..1fffa49
--- /dev/null
+++ b/adb/adb_auth.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __ADB_AUTH_H
+#define __ADB_AUTH_H
+
+void adb_auth_init(void);
+void adb_auth_verified(atransport *t);
+
+/* AUTH packets first argument */
+/* Request */
+#define ADB_AUTH_TOKEN 1
+/* Response */
+#define ADB_AUTH_SIGNATURE 2
+#define ADB_AUTH_RSAPUBLICKEY 3
+
+#if ADB_HOST
+
+int adb_auth_sign(void *key, void *token, size_t token_size, void *sig);
+void *adb_auth_nextkey(void *current);
+int adb_auth_get_userkey(unsigned char *data, size_t len);
+
+static inline int adb_auth_generate_token(void *token, size_t token_size) { return 0; }
+static inline int adb_auth_verify(void *token, void *sig, int siglen) { return 0; }
+static inline void adb_auth_confirm_key(unsigned char *data, size_t len, atransport *t) { }
+static inline void adb_auth_reload_keys(void) { }
+
+#else // !ADB_HOST
+
+static inline int adb_auth_sign(void* key, void *token, size_t token_size, void *sig) { return 0; }
+static inline void *adb_auth_nextkey(void *current) { return NULL; }
+static inline int adb_auth_get_userkey(unsigned char *data, size_t len) { return 0; }
+
+int adb_auth_generate_token(void *token, size_t token_size);
+int adb_auth_verify(void *token, void *sig, int siglen);
+void adb_auth_confirm_key(unsigned char *data, size_t len, atransport *t);
+void adb_auth_reload_keys(void);
+
+#endif // ADB_HOST
+
+#endif // __ADB_AUTH_H