diff --git a/keystore/tests/Android.bp b/keystore/tests/Android.bp
index 73459c1..103fa0e 100644
--- a/keystore/tests/Android.bp
+++ b/keystore/tests/Android.bp
@@ -8,6 +8,7 @@
         "-O0",
     ],
     srcs: [
+        "aaid_truncation_test.cpp",
         "auth_token_table_test.cpp",
         "auth_token_formatting_test.cpp",
         "confirmationui_rate_limiting_test.cpp",
@@ -17,13 +18,20 @@
     static_libs: [
         "android.hardware.confirmationui@1.0",
         "libbase",
+        "libcrypto",
+        "libcutils",
         "libgtest_main",
         "libhidlbase",
         "libkeymaster4support",
         "libkeystore_test",
         "liblog",
+        "libutils",
+        "libvndksupport",
     ],
-    shared_libs: ["libkeymaster_messages"],
+    shared_libs: [
+        "libbinder",
+        "libkeymaster_messages",
+    ],
    sanitize: {
      cfi: false,
    }
diff --git a/keystore/tests/aaid_truncation_test.cpp b/keystore/tests/aaid_truncation_test.cpp
new file mode 100644
index 0000000..e5d5e9f
--- /dev/null
+++ b/keystore/tests/aaid_truncation_test.cpp
@@ -0,0 +1,148 @@
+/*
+ * 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 <gtest/gtest.h>
+
+#include <string>
+#include <utils/String16.h>
+
+#include "../keystore_attestation_id.h"
+#include <keymaster/logger.h>
+
+#include <keystore/KeyAttestationApplicationId.h>
+#include <keystore/KeyAttestationPackageInfo.h>
+#include <keystore/Signature.h>
+
+using ::android::String16;
+using ::android::security::KEY_ATTESTATION_APPLICATION_ID_MAX_SIZE;
+using ::android::security::keymaster::KeyAttestationApplicationId;
+using ::android::security::keymaster::KeyAttestationPackageInfo;
+using std::vector;
+
+namespace keystore {
+
+namespace test {
+
+namespace {
+
+constexpr const char* kDummyPackageName = "DummyPackage";
+
+constexpr const char* kLongPackageName =
+    "a.long.package.name"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
+
+constexpr const char* kReasonablePackageName =
+    "a.reasonable.length.package.name"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
+
+constexpr const size_t kTooManyPackages = 4;
+
+// Signatures should be 32 bytes
+constexpr const uint8_t kDummySignature[32] = {
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f};
+constexpr const size_t kTooManySignatures = 35;
+
+}  // namespace
+
+using ::android::content::pm::Signature;
+using ::android::security::build_attestation_application_id;
+
+std::unique_ptr<KeyAttestationPackageInfo>
+make_package_info_with_signatures(const char* package_name,
+                                  KeyAttestationPackageInfo::SignaturesVector signatures) {
+    return std::make_unique<KeyAttestationPackageInfo>(
+        String16(package_name), 1 /* version code */,
+        std::make_shared<KeyAttestationPackageInfo::SignaturesVector>(std::move(signatures)));
+}
+
+std::unique_ptr<KeyAttestationPackageInfo> make_package_info(const char* package_name) {
+    return make_package_info_with_signatures(package_name,
+                                             KeyAttestationPackageInfo::SignaturesVector());
+}
+
+TEST(AaidTruncationTest, shortPackageInfoTest) {
+    KeyAttestationApplicationId app_id(make_package_info(kDummyPackageName));
+
+    auto result = build_attestation_application_id(app_id);
+    ASSERT_TRUE(result.isOk());
+    std::vector<uint8_t>& encoded_app_id = result;
+    ASSERT_LT(encoded_app_id.size(), KEY_ATTESTATION_APPLICATION_ID_MAX_SIZE);
+}
+
+TEST(AaidTruncationTest, tooLongPackageNameTest) {
+    KeyAttestationApplicationId app_id(make_package_info(kLongPackageName));
+
+    auto result = build_attestation_application_id(app_id);
+    ASSERT_TRUE(result.isOk());
+    std::vector<uint8_t>& encoded_app_id = result;
+    ASSERT_LT(encoded_app_id.size(), KEY_ATTESTATION_APPLICATION_ID_MAX_SIZE);
+}
+
+TEST(AaidTruncationTest, tooManySignaturesTest) {
+    std::vector<uint8_t> dummy_sig_data(kDummySignature, kDummySignature + 32);
+    KeyAttestationPackageInfo::SignaturesVector signatures;
+    // Add 35 signatures which will surely exceed the 1K limit.
+    for (size_t i = 0; i < kTooManySignatures; ++i) {
+        signatures.push_back(std::make_unique<Signature>(dummy_sig_data));
+    }
+
+    KeyAttestationApplicationId app_id(
+        make_package_info_with_signatures(kDummyPackageName, std::move(signatures)));
+
+    auto result = build_attestation_application_id(app_id);
+    ASSERT_TRUE(result.isOk());
+    std::vector<uint8_t>& encoded_app_id = result;
+    ASSERT_LT(encoded_app_id.size(), KEY_ATTESTATION_APPLICATION_ID_MAX_SIZE);
+}
+
+TEST(AaidTruncationTest, combinedPackagesAndSignaturesTest) {
+    std::vector<uint8_t> dummy_sig_data(kDummySignature, kDummySignature + 32);
+    KeyAttestationApplicationId::PackageInfoVector packages;
+
+    for (size_t i = 0; i < kTooManyPackages; ++i) {
+        KeyAttestationPackageInfo::SignaturesVector signatures;
+        // Add a few signatures for each package
+        for (int j = 0; j < 3; ++j) {
+            signatures.push_back(std::make_unique<Signature>(dummy_sig_data));
+        }
+        packages.push_back(
+            make_package_info_with_signatures(kReasonablePackageName, std::move(signatures)));
+    }
+
+    KeyAttestationApplicationId app_id(std::move(packages));
+    auto result = build_attestation_application_id(app_id);
+    ASSERT_TRUE(result.isOk());
+    std::vector<uint8_t>& encoded_app_id = result;
+    ASSERT_LT(encoded_app_id.size(), KEY_ATTESTATION_APPLICATION_ID_MAX_SIZE);
+}
+
+}  // namespace test
+}  // namespace keystore