From d05211870221e955b2a355c968b6866ab8e2f01a Mon Sep 17 00:00:00 2001
From: Branden Archer <brarcher@google.com>
Date: Thu, 15 Nov 2018 08:43:48 -0800
Subject: [PATCH] Run BoringSSL self test during startup

NIAP certification requires that all cryptographic functions
undergo a self-test during startup to demonstrate correct
operation. This change adds such a check.

If the check fails, it will prevent the device from booting
by rebooting into the bootloader.

Bug: 119826244
Test: Built for walleye. After device booted examined dmesg and
      observed logs from init showing that the new task did
      start. Further, when BoringSSL is built to fail its self
      check the device did stop during a normal boot and enter
      the bootloader, and did so before the boot animation stopped.

Change-Id: I07a5dc73a314502c87de566bb26f4d73499d2675
---
 init/Android.bp              |  2 ++
 init/boringssl_self_test.cpp | 56 ++++++++++++++++++++++++++++++++++++
 init/boringssl_self_test.h   | 28 ++++++++++++++++++
 init/init.cpp                |  4 +++
 4 files changed, 90 insertions(+)
 create mode 100644 init/boringssl_self_test.cpp
 create mode 100644 init/boringssl_self_test.h

diff --git a/init/Android.bp b/init/Android.bp
index ff3b61fe2..90ea59650 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -71,6 +71,7 @@ cc_defaults {
         "libbinder",
         "libbootloader_message",
         "libcutils",
+        "libcrypto",
         "libdl",
         "libext4_utils",
         "libfs_mgr",
@@ -92,6 +93,7 @@ cc_library_static {
         "action.cpp",
         "action_manager.cpp",
         "action_parser.cpp",
+        "boringssl_self_test.cpp",
         "bootchart.cpp",
         "builtins.cpp",
         "capabilities.cpp",
diff --git a/init/boringssl_self_test.cpp b/init/boringssl_self_test.cpp
new file mode 100644
index 000000000..0408d30eb
--- /dev/null
+++ b/init/boringssl_self_test.cpp
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#include "boringssl_self_test.h"
+
+#include <android-base/logging.h>
+#include <cutils/android_reboot.h>
+#include <openssl/crypto.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+namespace android {
+namespace init {
+
+Result<Success> StartBoringSslSelfTest(const BuiltinArguments&) {
+    pid_t id = fork();
+
+    if (id == 0) {
+        if (BORINGSSL_self_test() != 1) {
+            LOG(INFO) << "BoringSSL crypto self tests failed";
+
+            // This check has failed, so the device should refuse
+            // to boot. Rebooting to bootloader to wait for
+            // further action from the user.
+
+            int result = android_reboot(ANDROID_RB_RESTART2, 0,
+                                        "bootloader,boringssl-self-check-failed");
+            if (result != 0) {
+                LOG(ERROR) << "Failed to reboot into bootloader";
+            }
+        }
+
+        _exit(0);
+    } else if (id == -1) {
+        // Failed to fork, so cannot run the test. Refuse to continue.
+        PLOG(FATAL) << "Failed to fork for BoringSSL self test";
+    }
+
+    return Success();
+}
+
+}  // namespace init
+}  // namespace android
diff --git a/init/boringssl_self_test.h b/init/boringssl_self_test.h
new file mode 100644
index 000000000..b21fc7883
--- /dev/null
+++ b/init/boringssl_self_test.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#pragma once
+
+#include "builtin_arguments.h"
+#include "result.h"
+
+namespace android {
+namespace init {
+
+Result<Success> StartBoringSslSelfTest(const BuiltinArguments&);
+
+}  // namespace init
+}  // namespace android
diff --git a/init/init.cpp b/init/init.cpp
index e7dbc1197..a8d1a27c9 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -49,6 +49,7 @@
 #endif
 
 #include "action_parser.h"
+#include "boringssl_self_test.h"
 #include "epoll.h"
 #include "first_stage_mount.h"
 #include "import_parser.h"
@@ -768,6 +769,9 @@ int main(int argc, char** argv) {
     // Trigger all the boot actions to get us started.
     am.QueueEventTrigger("init");
 
+    // Starting the BoringSSL self test, for NIAP certification compliance.
+    am.QueueBuiltinAction(StartBoringSslSelfTest, "StartBoringSslSelfTest");
+
     // Repeat mix_hwrng_into_linux_rng in case /dev/hw_random or /dev/random
     // wasn't ready immediately after wait_for_coldboot_done
     am.QueueBuiltinAction(MixHwrngIntoLinuxRngAction, "MixHwrngIntoLinuxRng");