1 files changed, 117 insertions, 0 deletions
diff --git a/identity/aidl/default/Util.cpp b/identity/aidl/default/Util.cpp
new file mode 100644
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--- /dev/null
+++ b/identity/aidl/default/Util.cpp
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2019, 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 "Util"
+
+#include "Util.h"
+
+#include <android/hardware/identity/support/IdentityCredentialSupport.h>
+
+#include <string.h>
+
+#include <android-base/logging.h>
+
+#include <cppbor.h>
+#include <cppbor_parse.h>
+
+namespace aidl::android::hardware::identity {
+
+using namespace ::android::hardware::identity;
+
+// This is not a very random HBK but that's OK because this is the SW
+// implementation where it can't be kept secret.
+vector<uint8_t> hardwareBoundKey = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
+
+const vector<uint8_t>& getHardwareBoundKey() {
+    return hardwareBoundKey;
+}
+
+vector<uint8_t> byteStringToUnsigned(const vector<int8_t>& value) {
+    return vector<uint8_t>(value.begin(), value.end());
+}
+
+vector<int8_t> byteStringToSigned(const vector<uint8_t>& value) {
+    return vector<int8_t>(value.begin(), value.end());
+}
+
+vector<uint8_t> secureAccessControlProfileEncodeCbor(const SecureAccessControlProfile& profile) {
+    cppbor::Map map;
+    map.add("id", profile.id);
+
+    if (profile.readerCertificate.encodedCertificate.size() > 0) {
+        map.add("readerCertificate",
+                cppbor::Bstr(byteStringToUnsigned(profile.readerCertificate.encodedCertificate)));
+    }
+
+    if (profile.userAuthenticationRequired) {
+        map.add("userAuthenticationRequired", profile.userAuthenticationRequired);
+        map.add("timeoutMillis", profile.timeoutMillis);
+        map.add("secureUserId", profile.secureUserId);
+    }
+
+    return map.encode();
+}
+
+optional<vector<uint8_t>> secureAccessControlProfileCalcMac(
+        const SecureAccessControlProfile& profile, const vector<uint8_t>& storageKey) {
+    vector<uint8_t> cborData = secureAccessControlProfileEncodeCbor(profile);
+
+    optional<vector<uint8_t>> nonce = support::getRandom(12);
+    if (!nonce) {
+        return {};
+    }
+    optional<vector<uint8_t>> macO =
+            support::encryptAes128Gcm(storageKey, nonce.value(), {}, cborData);
+    if (!macO) {
+        return {};
+    }
+    return macO.value();
+}
+
+bool secureAccessControlProfileCheckMac(const SecureAccessControlProfile& profile,
+                                        const vector<uint8_t>& storageKey) {
+    vector<uint8_t> cborData = secureAccessControlProfileEncodeCbor(profile);
+
+    if (profile.mac.size() < support::kAesGcmIvSize) {
+        return false;
+    }
+    vector<uint8_t> nonce =
+            vector<uint8_t>(profile.mac.begin(), profile.mac.begin() + support::kAesGcmIvSize);
+    optional<vector<uint8_t>> mac = support::encryptAes128Gcm(storageKey, nonce, {}, cborData);
+    if (!mac) {
+        return false;
+    }
+    if (mac.value() != byteStringToUnsigned(profile.mac)) {
+        return false;
+    }
+    return true;
+}
+
+vector<uint8_t> entryCreateAdditionalData(const string& nameSpace, const string& name,
+                                          const vector<int32_t> accessControlProfileIds) {
+    cppbor::Map map;
+    map.add("Namespace", nameSpace);
+    map.add("Name", name);
+
+    cppbor::Array acpIds;
+    for (auto id : accessControlProfileIds) {
+        acpIds.add(id);
+    }
+    map.add("AccessControlProfileIds", std::move(acpIds));
+    return map.encode();
+}
+
+}  // namespace aidl::android::hardware::identity