identity: fix access control checks in libeic.
Also add a new libeic_test binary which has a regression test for this
vulnerability.
Bug: 190757775
Test: atest libeic_test
Test: atest VtsHalIdentityTargetTest
Test: atest CtsIdentityTestCases
Change-Id: I8344655c59930d6bf1baa4e0f8d0f60e4fc9e48d
diff --git a/identity/TEST_MAPPING b/identity/TEST_MAPPING
index f35f4b7..85cf91f 100644
--- a/identity/TEST_MAPPING
+++ b/identity/TEST_MAPPING
@@ -8,6 +8,9 @@
},
{
"name": "android.hardware.identity-support-lib-test"
+ },
+ {
+ "name": "libeic_test"
}
]
}
diff --git a/identity/aidl/default/Android.bp b/identity/aidl/default/Android.bp
index 7c68aee..28c4893 100644
--- a/identity/aidl/default/Android.bp
+++ b/identity/aidl/default/Android.bp
@@ -114,6 +114,43 @@
],
}
+cc_test {
+ name: "libeic_test",
+ srcs: [
+ "EicTests.cpp",
+ "FakeSecureHardwareProxy.cpp",
+ ],
+ cflags: [
+ "-Wall",
+ "-Wextra",
+ "-g",
+ "-DEIC_DEBUG",
+ ],
+ local_include_dirs: [
+ "common",
+ ],
+ shared_libs: [
+ "liblog",
+ "libcrypto",
+ "libkeymaster_messages",
+ ],
+ static_libs: [
+ "libbase",
+ "libcppbor_external",
+ "libcppcose_rkp",
+ "libutils",
+ "libsoft_attestation_cert",
+ "libkeymaster_portable",
+ "libsoft_attestation_cert",
+ "libpuresoftkeymasterdevice",
+ "android.hardware.identity-support-lib",
+ "android.hardware.identity-libeic-library",
+ ],
+ test_suites: [
+ "general-tests",
+ ],
+}
+
prebuilt_etc {
name: "android.hardware.identity_credential.xml",
sub_dir: "permissions",
diff --git a/identity/aidl/default/EicTests.cpp b/identity/aidl/default/EicTests.cpp
new file mode 100644
index 0000000..a28080d
--- /dev/null
+++ b/identity/aidl/default/EicTests.cpp
@@ -0,0 +1,85 @@
+/*
+ * 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.
+ */
+
+#include <gtest/gtest.h>
+#include <optional>
+#include <string>
+#include <vector>
+
+#include "FakeSecureHardwareProxy.h"
+
+// Most of libeic is tested as part of VTS since there's almost a 1:1 mapping between
+// the HAL and libeic interfaces. This test suite is mainly for the few things which
+// doesn't map directly.
+//
+
+using std::optional;
+using std::string;
+using std::vector;
+
+using android::hardware::identity::AccessCheckResult;
+using android::hardware::identity::FakeSecureHardwarePresentationProxy;
+using android::hardware::identity::FakeSecureHardwareProvisioningProxy;
+
+TEST(EicTest, AccessControlIsEnforced) {
+ // First provision the credential...
+ //
+ FakeSecureHardwareProvisioningProxy provisioningProxy;
+ bool isTestCredential = false;
+ provisioningProxy.initialize(isTestCredential);
+ optional<vector<uint8_t>> credKey =
+ provisioningProxy.createCredentialKey({0x01, 0x02}, {0x03, 0x04});
+ ASSERT_TRUE(credKey.has_value());
+ string docType = "org.iso.18013.5.1.mDL";
+ ASSERT_TRUE(provisioningProxy.startPersonalization(0, {1}, docType, 125));
+
+ vector<int> acpIds = {};
+ string nameSpace = "org.iso.18013.5.1";
+ string name = "NonAccessibleElement";
+ vector<uint8_t> content = {0x63, 0x46, 0x6f, 0x6f}; // "Foo" tstr
+ ASSERT_TRUE(provisioningProxy.beginAddEntry(acpIds, nameSpace, name, content.size()));
+ optional<vector<uint8_t>> encContent =
+ provisioningProxy.addEntryValue(acpIds, nameSpace, name, content);
+ ASSERT_TRUE(encContent.has_value());
+ ASSERT_EQ(encContent->size(), content.size() + 28);
+
+ optional<vector<uint8_t>> signatureOfToBeSigned = provisioningProxy.finishAddingEntries();
+ ASSERT_TRUE(signatureOfToBeSigned.has_value());
+
+ optional<vector<uint8_t>> credData = provisioningProxy.finishGetCredentialData(docType);
+ ASSERT_TRUE(credData.has_value());
+ ASSERT_TRUE(provisioningProxy.shutdown());
+
+ // Then present data from it...
+ //
+ FakeSecureHardwarePresentationProxy presentationProxy;
+ ASSERT_TRUE(presentationProxy.initialize(isTestCredential, docType, credData.value()));
+ AccessCheckResult res =
+ presentationProxy.startRetrieveEntryValue(nameSpace, name, 1, content.size(), acpIds);
+ ASSERT_EQ(res, AccessCheckResult::kNoAccessControlProfiles);
+
+ // Ensure that we can't get the data out if startRetrieveEntryValue() returned
+ // something other than kOk... See b/190757775 for details.
+ //
+ optional<vector<uint8_t>> decContent =
+ presentationProxy.retrieveEntryValue(encContent.value(), nameSpace, name, acpIds);
+ ASSERT_FALSE(decContent.has_value());
+}
+
+int main(int argc, char** argv) {
+ ::testing::InitGoogleTest(&argc, argv);
+ return RUN_ALL_TESTS();
+}
diff --git a/identity/aidl/default/libeic/EicPresentation.c b/identity/aidl/default/libeic/EicPresentation.c
index 9e033b3..3d13766 100644
--- a/identity/aidl/default/libeic/EicPresentation.c
+++ b/identity/aidl/default/libeic/EicPresentation.c
@@ -633,6 +633,8 @@
// We'll need to calc and store a digest of additionalData to check that it's the same
// additionalData being passed in for every eicPresentationRetrieveEntryValue() call...
+ //
+ ctx->accessCheckOk = false;
if (!eicCborCalcEntryAdditionalData(accessControlProfileIds, numAccessControlProfileIds,
nameSpace, name, additionalDataCbor,
additionalDataCborBufSize, &additionalDataCborSize,
@@ -680,6 +682,7 @@
if (result == EIC_ACCESS_CHECK_RESULT_OK) {
eicCborAppendString(&ctx->cbor, name);
+ ctx->accessCheckOk = true;
}
return result;
}
@@ -702,10 +705,15 @@
calculatedSha256)) {
return false;
}
+
if (eicCryptoMemCmp(calculatedSha256, ctx->additionalDataSha256, EIC_SHA256_DIGEST_SIZE) != 0) {
eicDebug("SHA-256 mismatch of additionalData");
return false;
}
+ if (!ctx->accessCheckOk) {
+ eicDebug("Attempting to retrieve a value for which access is not granted");
+ return false;
+ }
if (!eicOpsDecryptAes128Gcm(ctx->storageKey, encryptedContent, encryptedContentSize,
additionalDataCbor, additionalDataCborSize, content)) {
diff --git a/identity/aidl/default/libeic/EicPresentation.h b/identity/aidl/default/libeic/EicPresentation.h
index 7cad068..c888049 100644
--- a/identity/aidl/default/libeic/EicPresentation.h
+++ b/identity/aidl/default/libeic/EicPresentation.h
@@ -70,6 +70,10 @@
// Set to true initialized as a test credential.
bool testCredential;
+ // Set to true if the evaluation of access control checks in
+ // eicPresentationStartRetrieveEntryValue() resulted EIC_ACCESS_CHECK_RESULT_OK
+ bool accessCheckOk;
+
// These are bitmasks indicating which of the possible 32 access control profiles are
// authorized. They are built up by eicPresentationValidateAccessControlProfile().
//