Add a unit test for remote_prov_utils

This functionality will be used for the factory tooling, so we should
test it. Additionally, some new functionality will soon be added, and
it also needs to be tested.

Test: libkeymint_remote_prov_support_test
Bug: 191301285
Change-Id: I6a8798fc4b09fff1e829185a4b9e471921e5d2a9
Merged-In: I6a8798fc4b09fff1e829185a4b9e471921e5d2a9

security/keymint/support/Android.bp

@@ -62,3 +62,19 @@ cc_library {
         "libcrypto",
     ],
 }
+
+cc_test {
+    name: "libkeymint_remote_prov_support_test",
+    srcs: ["remote_prov_utils_test.cpp"],
+    static_libs: [
+        "libgmock",
+        "libgtest_main",
+    ],
+    shared_libs: [
+        "libcppbor_external",
+        "libcppcose_rkp",
+        "libcrypto",
+        "libkeymaster_portable",
+        "libkeymint_remote_prov_support",
+    ],
+}

security/keymint/support/remote_prov_utils.cpp

@@ -31,6 +31,10 @@ bytevec randomBytes(size_t numBytes) {
 }
 
 ErrMsgOr<EekChain> generateEekChain(size_t length, const bytevec& eekId) {
+    if (length < 2) {
+        return "EEK chain must contain at least 2 certs.";
+    }
+
     auto eekChain = cppbor::Array();
 
     bytevec prev_priv_key;

security/keymint/support/remote_prov_utils_test.cpp

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2021 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 <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <keymaster/android_keymaster_utils.h>
+#include <keymaster/remote_provisioning_utils.h>
+#include <openssl/curve25519.h>
+#include <remote_prov/remote_prov_utils.h>
+#include <cstdint>
+
+namespace aidl::android::hardware::security::keymint::remote_prov {
+namespace {
+
+using ::keymaster::KeymasterBlob;
+using ::keymaster::validateAndExtractEekPubAndId;
+using ::testing::ElementsAreArray;
+
+TEST(RemoteProvUtilsTest, GenerateEekChainInvalidLength) {
+    ASSERT_FALSE(generateEekChain(1, /*eekId=*/{}));
+}
+
+TEST(RemoteProvUtilsTest, GenerateEekChain) {
+    bytevec kTestEekId = {'t', 'e', 's', 't', 'I', 'd', 0};
+    for (size_t length : {2, 3, 31}) {
+        auto get_eek_result = generateEekChain(length, kTestEekId);
+        ASSERT_TRUE(get_eek_result) << get_eek_result.message();
+
+        auto& [chain, pubkey, privkey] = *get_eek_result;
+
+        auto validation_result = validateAndExtractEekPubAndId(
+                /*testMode=*/true, KeymasterBlob(chain.data(), chain.size()));
+        ASSERT_TRUE(validation_result.isOk());
+
+        auto& [eekPub, eekId] = *validation_result;
+        EXPECT_THAT(eekId, ElementsAreArray(kTestEekId));
+        EXPECT_THAT(eekPub, ElementsAreArray(pubkey));
+    }
+}
+
+}  // namespace
+}  // namespace aidl::android::hardware::security::keymint::remote_prov