Provide alternate SE RoT provisioning path.

On some devices it is infeasible to provision the KeyMint RoT bits in
the Android Bootloader.  This provides an alternate path to provision
them from the TEE during early boot.

Bug: 219076736
Test: VtsAidlKeyMintTargetTest
Change-Id: If69f7e25e58edbf4d2190084e2c0a03a94bfa5d6
Merged-In: If69f7e25e58edbf4d2190084e2c0a03a94bfa5d6

1 files changed, 255 insertions, 0 deletions

diff --git a/security/keymint/aidl/vts/functional/SecureElementProvisioningTest.cpp b/security/keymint/aidl/vts/functional/SecureElementProvisioningTest.cpp
new file mode 100644
index 0000000000..e16a47b0c1
--- /dev/null
+++ b/security/keymint/aidl/vts/functional/SecureElementProvisioningTest.cpp
@@ -0,0 +1,255 @@
+/*
+ * Copyright (C) 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.
+ */
+
+#define LOG_TAG "keymint_2_se_provisioning_test"
+
+#include <map>
+#include <memory>
+#include <vector>
+
+#include <android-base/logging.h>
+#include <android/binder_manager.h>
+
+#include <cppbor_parse.h>
+#include <keymaster/cppcose/cppcose.h>
+#include <keymint_support/key_param_output.h>
+
+#include "KeyMintAidlTestBase.h"
+
+namespace aidl::android::hardware::security::keymint::test {
+
+using std::array;
+using std::map;
+using std::shared_ptr;
+using std::vector;
+
+class SecureElementProvisioningTest : public testing::Test {
+  protected:
+    static void SetupTestSuite() {
+        auto params = ::android::getAidlHalInstanceNames(IKeyMintDevice::descriptor);
+        for (auto& param : params) {
+            ASSERT_TRUE(AServiceManager_isDeclared(param.c_str()))
+                    << "IKeyMintDevice instance " << param << " found but not declared.";
+            ::ndk::SpAIBinder binder(AServiceManager_waitForService(param.c_str()));
+            auto keymint = IKeyMintDevice::fromBinder(binder);
+            ASSERT_NE(keymint, nullptr) << "Failed to get IKeyMintDevice instance " << param;
+
+            KeyMintHardwareInfo info;
+            ASSERT_TRUE(keymint->getHardwareInfo(&info).isOk());
+            ASSERT_EQ(keymints_.count(info.securityLevel), 0)
+                    << "There must be exactly one IKeyMintDevice with security level "
+                    << info.securityLevel;
+
+            keymints_[info.securityLevel] = std::move(keymint);
+        }
+    }
+
+    static map<SecurityLevel, shared_ptr<IKeyMintDevice>> keymints_;
+};
+
+map<SecurityLevel, shared_ptr<IKeyMintDevice>> SecureElementProvisioningTest::keymints_;
+
+TEST_F(SecureElementProvisioningTest, ValidConfigurations) {
+    // TEE is required
+    ASSERT_EQ(keymints_.count(SecurityLevel::TRUSTED_ENVIRONMENT), 1);
+    // StrongBox is optional
+    ASSERT_LE(keymints_.count(SecurityLevel::STRONGBOX), 1);
+}
+
+TEST_F(SecureElementProvisioningTest, TeeOnly) {
+    ASSERT_EQ(keymints_.count(SecurityLevel::TRUSTED_ENVIRONMENT), 1);
+    auto tee = keymints_.find(SecurityLevel::TRUSTED_ENVIRONMENT)->second;
+    ASSERT_NE(tee, nullptr);
+
+    array<uint8_t, 16> challenge1 = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+    array<uint8_t, 16> challenge2 = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+
+    vector<uint8_t> rootOfTrust1;
+    Status result = tee->getRootOfTrust(challenge1, &rootOfTrust1);
+
+    // TODO: Remove the next line to require TEEs to succeed.
+    if (!result.isOk()) return;
+
+    ASSERT_TRUE(result.isOk());
+
+    // TODO:  Parse and validate rootOfTrust1 here
+
+    vector<uint8_t> rootOfTrust2;
+    result = tee->getRootOfTrust(challenge2, &rootOfTrust2);
+    ASSERT_TRUE(result.isOk());
+
+    // TODO:  Parse and validate rootOfTrust2 here
+
+    ASSERT_NE(rootOfTrust1, rootOfTrust2);
+
+    vector<uint8_t> rootOfTrust3;
+    result = tee->getRootOfTrust(challenge1, &rootOfTrust3);
+    ASSERT_TRUE(result.isOk());
+
+    ASSERT_EQ(rootOfTrust1, rootOfTrust3);
+
+    // TODO:  Parse and validate rootOfTrust3 here
+}
+
+TEST_F(SecureElementProvisioningTest, TeeDoesNotImplementStrongBoxMethods) {
+    ASSERT_EQ(keymints_.count(SecurityLevel::TRUSTED_ENVIRONMENT), 1);
+    auto tee = keymints_.find(SecurityLevel::TRUSTED_ENVIRONMENT)->second;
+    ASSERT_NE(tee, nullptr);
+
+    array<uint8_t, 16> challenge;
+    Status result = tee->getRootOfTrustChallenge(&challenge);
+    ASSERT_FALSE(result.isOk());
+    ASSERT_EQ(result.getExceptionCode(), EX_SERVICE_SPECIFIC);
+    ASSERT_EQ(static_cast<ErrorCode>(result.getServiceSpecificError()), ErrorCode::UNIMPLEMENTED);
+
+    result = tee->sendRootOfTrust({});
+    ASSERT_FALSE(result.isOk());
+    ASSERT_EQ(result.getExceptionCode(), EX_SERVICE_SPECIFIC);
+    ASSERT_EQ(static_cast<ErrorCode>(result.getServiceSpecificError()), ErrorCode::UNIMPLEMENTED);
+}
+
+TEST_F(SecureElementProvisioningTest, StrongBoxDoesNotImplementTeeMethods) {
+    if (keymints_.count(SecurityLevel::STRONGBOX) == 0) return;
+
+    auto sb = keymints_.find(SecurityLevel::STRONGBOX)->second;
+    ASSERT_NE(sb, nullptr);
+
+    vector<uint8_t> rootOfTrust;
+    Status result = sb->getRootOfTrust({}, &rootOfTrust);
+    ASSERT_FALSE(result.isOk());
+    ASSERT_EQ(result.getExceptionCode(), EX_SERVICE_SPECIFIC);
+    ASSERT_EQ(static_cast<ErrorCode>(result.getServiceSpecificError()), ErrorCode::UNIMPLEMENTED);
+}
+
+TEST_F(SecureElementProvisioningTest, UnimplementedTest) {
+    if (keymints_.count(SecurityLevel::STRONGBOX) == 0) return;  // Need a StrongBox to provision.
+
+    ASSERT_EQ(keymints_.count(SecurityLevel::TRUSTED_ENVIRONMENT), 1);
+    auto tee = keymints_.find(SecurityLevel::TRUSTED_ENVIRONMENT)->second;
+    ASSERT_NE(tee, nullptr);
+
+    ASSERT_EQ(keymints_.count(SecurityLevel::STRONGBOX), 1);
+    auto sb = keymints_.find(SecurityLevel::STRONGBOX)->second;
+    ASSERT_NE(sb, nullptr);
+
+    array<uint8_t, 16> challenge;
+    Status result = sb->getRootOfTrustChallenge(&challenge);
+    if (!result.isOk()) {
+        // Strongbox does not have to implement this feature if it has uses an alternative mechanism
+        // to provision the root of trust.  In that case it MUST return UNIMPLEMENTED, both from
+        // getRootOfTrustChallenge() and from sendRootOfTrust().
+        ASSERT_EQ(result.getExceptionCode(), EX_SERVICE_SPECIFIC);
+        ASSERT_EQ(static_cast<ErrorCode>(result.getServiceSpecificError()),
+                  ErrorCode::UNIMPLEMENTED);
+
+        result = sb->sendRootOfTrust({});
+        ASSERT_EQ(result.getExceptionCode(), EX_SERVICE_SPECIFIC);
+        ASSERT_EQ(static_cast<ErrorCode>(result.getServiceSpecificError()),
+                  ErrorCode::UNIMPLEMENTED);
+
+        SUCCEED() << "This Strongbox implementation does not use late root of trust delivery.";
+        return;
+    }
+}
+
+TEST_F(SecureElementProvisioningTest, ChallengeQualityTest) {
+    if (keymints_.count(SecurityLevel::STRONGBOX) == 0) return;  // Need a StrongBox to provision.
+
+    ASSERT_EQ(keymints_.count(SecurityLevel::STRONGBOX), 1);
+    auto sb = keymints_.find(SecurityLevel::STRONGBOX)->second;
+    ASSERT_NE(sb, nullptr);
+
+    array<uint8_t, 16> challenge1;
+    Status result = sb->getRootOfTrustChallenge(&challenge1);
+    if (!result.isOk()) return;
+
+    array<uint8_t, 16> challenge2;
+    result = sb->getRootOfTrustChallenge(&challenge2);
+    ASSERT_TRUE(result.isOk());
+    ASSERT_NE(challenge1, challenge2);
+
+    // TODO: When we add entropy testing in other relevant places in these tests, add it here, too,
+    // to verify that challenges appear to have adequate entropy.
+}
+
+TEST_F(SecureElementProvisioningTest, ProvisioningTest) {
+    if (keymints_.count(SecurityLevel::STRONGBOX) == 0) return;  // Need a StrongBox to provision.
+
+    ASSERT_EQ(keymints_.count(SecurityLevel::TRUSTED_ENVIRONMENT), 1);
+    auto tee = keymints_.find(SecurityLevel::TRUSTED_ENVIRONMENT)->second;
+    ASSERT_NE(tee, nullptr);
+
+    ASSERT_EQ(keymints_.count(SecurityLevel::STRONGBOX), 1);
+    auto sb = keymints_.find(SecurityLevel::STRONGBOX)->second;
+    ASSERT_NE(sb, nullptr);
+
+    array<uint8_t, 16> challenge;
+    Status result = sb->getRootOfTrustChallenge(&challenge);
+    if (!result.isOk()) return;
+
+    vector<uint8_t> rootOfTrust;
+    result = tee->getRootOfTrust(challenge, &rootOfTrust);
+    ASSERT_TRUE(result.isOk());
+
+    // TODO: Verify COSE_Mac0 structure and content here.
+
+    result = sb->sendRootOfTrust(rootOfTrust);
+    ASSERT_TRUE(result.isOk());
+
+    // Sending again must fail, because a new challenge is required.
+    result = sb->sendRootOfTrust(rootOfTrust);
+    ASSERT_FALSE(result.isOk());
+}
+
+TEST_F(SecureElementProvisioningTest, InvalidProvisioningTest) {
+    if (keymints_.count(SecurityLevel::STRONGBOX) == 0) return;  // Need a StrongBox to provision.
+
+    ASSERT_EQ(keymints_.count(SecurityLevel::TRUSTED_ENVIRONMENT), 1);
+    auto tee = keymints_.find(SecurityLevel::TRUSTED_ENVIRONMENT)->second;
+    ASSERT_NE(tee, nullptr);
+
+    ASSERT_EQ(keymints_.count(SecurityLevel::STRONGBOX), 1);
+    auto sb = keymints_.find(SecurityLevel::STRONGBOX)->second;
+    ASSERT_NE(sb, nullptr);
+
+    array<uint8_t, 16> challenge;
+    Status result = sb->getRootOfTrustChallenge(&challenge);
+    if (!result.isOk()) return;
+
+    result = sb->sendRootOfTrust({});
+    ASSERT_FALSE(result.isOk());
+    ASSERT_EQ(result.getExceptionCode(), EX_SERVICE_SPECIFIC);
+    ASSERT_EQ(static_cast<ErrorCode>(result.getServiceSpecificError()),
+              ErrorCode::VERIFICATION_FAILED);
+
+    vector<uint8_t> rootOfTrust;
+    result = tee->getRootOfTrust(challenge, &rootOfTrust);
+    ASSERT_TRUE(result.isOk());
+
+    vector<uint8_t> corruptedRootOfTrust = rootOfTrust;
+    corruptedRootOfTrust[corruptedRootOfTrust.size() / 2]++;
+    result = sb->sendRootOfTrust(corruptedRootOfTrust);
+    ASSERT_FALSE(result.isOk());
+    ASSERT_EQ(result.getExceptionCode(), EX_SERVICE_SPECIFIC);
+    ASSERT_EQ(static_cast<ErrorCode>(result.getServiceSpecificError()),
+              ErrorCode::VERIFICATION_FAILED);
+
+    // Now try the correct RoT
+    result = sb->sendRootOfTrust(rootOfTrust);
+    ASSERT_TRUE(result.isOk());
+}
+
+}  // namespace aidl::android::hardware::security::keymint::test