Add compatibility wrapper

This implements the Keymint 1 spec by wrapping the legacy Keymaster
implementation.

Test: atest keystore2_km_compat_test
Test: atest keystore2_certificate_test
Test: Manually verify that keystore2 can find a legacy implementation.
Change-Id: Ia56c25eed0f97a7e6194954a655ceb62259b3273
diff --git a/keystore2/src/km_compat/Android.bp b/keystore2/src/km_compat/Android.bp
new file mode 100644
index 0000000..01cf2cc
--- /dev/null
+++ b/keystore2/src/km_compat/Android.bp
@@ -0,0 +1,105 @@
+// Copyright 2020, 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.
+
+rust_library {
+    name: "libkeystore2_km_compat",
+    crate_name: "keystore2_km_compat",
+    srcs: ["lib.rs"],
+
+    rustlibs: [
+        "android.hardware.security.keymint-rust",
+        "android.security.compat-rust",
+    ],
+    shared_libs: [
+        "libkm_compat_service",
+    ]
+}
+
+rust_test {
+    name: "keystore2_km_compat_test",
+    crate_name: "keystore2",
+    srcs: ["lib.rs"],
+    test_suites: ["general-tests"],
+    auto_gen_config: true,
+    rustlibs: [
+        "android.hardware.security.keymint-rust",
+        "android.security.compat-rust",
+    ],
+    shared_libs: [
+        "libkm_compat_service",
+    ],
+}
+
+cc_library {
+    name: "libkm_compat",
+    srcs: ["km_compat.cpp"],
+    shared_libs: [
+        "android.hardware.keymaster@3.0",
+        "android.hardware.keymaster@4.0",
+        "android.hardware.keymaster@4.1",
+        "android.hardware.security.keymint-unstable-ndk_platform",
+        "android.security.compat-ndk_platform",
+        "android.system.keystore2-ndk_platform",
+        "libbase",
+        "libbinder_ndk",
+        "libcrypto",
+        "libhidlbase",
+        "libkeymaster4_1support",
+        "libkeystore2_crypto",
+        "libutils",
+    ],
+}
+
+cc_library {
+    name: "libkm_compat_service",
+    srcs: ["km_compat_service.cpp"],
+    shared_libs: [
+        "android.security.compat-ndk_platform",
+        "libbinder_ndk",
+        "libcrypto",
+        "libkm_compat",
+        "libkeymaster4_1support",
+        "libkeystore2_crypto",
+    ],
+}
+
+cc_test {
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wextra",
+    ],
+    srcs: [
+        "certificate_test.cpp",
+        "gtest_main.cpp",
+        "slot_test.cpp",
+    ],
+    shared_libs: [
+        "android.hardware.keymaster@3.0",
+        "android.hardware.keymaster@4.0",
+        "android.hardware.keymaster@4.1",
+        "android.hardware.security.keymint-unstable-ndk_platform",
+        "android.security.compat-ndk_platform",
+        "android.system.keystore2-ndk_platform",
+        "libbase",
+        "libbinder_ndk",
+        "libcrypto",
+        "libhidlbase",
+        "libkeymaster4_1support",
+        "libkeystore2_crypto",
+        "libkm_compat",
+        "libutils",
+    ],
+    name: "keystore2_certificate_test",
+}