Identity Credential: Switch default implementation to use libeic.

Introduce platform-neutral C library ("libeic") which can be used to
implement an Identity Credential Trusted Application/Applet in Secure
Hardware.

The libeic library is intentionally low-level, has no dependencies
(not even libc), uses very little run-time memory (less than 500 bytes
during a provisioning or presentation session), and doesn't
dynamically allocate any memory. Crypto routines are provided by the
library user through a simple crypto interface defined in EicOps.

Also provide an Android-side HAL implementation designed to
communicate with libeic running in Secure Hardware outside
Android. Abstract out communications between HAL and TA in a couple of
SecureHardwareProxy* classes which mimic libeic 1:1.

The default implementation of the HAL is a combination of the
aforementioned HAL using libeic in-process backed by BoringSSL for the
crypto bits.

Test: atest VtsHalIdentityTargetTest
Test: atest android.security.identity.cts
Bug: 170146643
Change-Id: I3bf43fa7fd9362f94023052591801f2094a04607

1 files changed, 76 insertions, 0 deletions

diff --git a/identity/aidl/default/common/IdentityCredentialStore.cpp b/identity/aidl/default/common/IdentityCredentialStore.cpp
new file mode 100644
index 0000000000..13f91aacf9
--- /dev/null
+++ b/identity/aidl/default/common/IdentityCredentialStore.cpp
@@ -0,0 +1,76 @@
+/*
+ * 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 "IdentityCredentialStore"
+
+#include <android-base/logging.h>
+
+#include "IdentityCredential.h"
+#include "IdentityCredentialStore.h"
+#include "WritableIdentityCredential.h"
+
+namespace aidl::android::hardware::identity {
+
+ndk::ScopedAStatus IdentityCredentialStore::getHardwareInformation(
+        HardwareInformation* hardwareInformation) {
+    HardwareInformation hw;
+    hw.credentialStoreName = "Identity Credential Reference Implementation";
+    hw.credentialStoreAuthorName = "Google";
+    hw.dataChunkSize = kGcmChunkSize;
+    hw.isDirectAccess = false;
+    hw.supportedDocTypes = {};
+    *hardwareInformation = hw;
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus IdentityCredentialStore::createCredential(
+        const string& docType, bool testCredential,
+        shared_ptr<IWritableIdentityCredential>* outWritableCredential) {
+    sp<SecureHardwareProvisioningProxy> hwProxy = hwProxyFactory_->createProvisioningProxy();
+    shared_ptr<WritableIdentityCredential> wc =
+            ndk::SharedRefBase::make<WritableIdentityCredential>(hwProxy, docType, testCredential);
+    if (!wc->initialize()) {
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED,
+                "Error initializing WritableIdentityCredential"));
+    }
+    *outWritableCredential = wc;
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus IdentityCredentialStore::getCredential(
+        CipherSuite cipherSuite, const vector<uint8_t>& credentialData,
+        shared_ptr<IIdentityCredential>* outCredential) {
+    // We only support CIPHERSUITE_ECDHE_HKDF_ECDSA_WITH_AES_256_GCM_SHA256 right now.
+    if (cipherSuite != CipherSuite::CIPHERSUITE_ECDHE_HKDF_ECDSA_WITH_AES_256_GCM_SHA256) {
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_CIPHER_SUITE_NOT_SUPPORTED,
+                "Unsupported cipher suite"));
+    }
+
+    sp<SecureHardwarePresentationProxy> hwProxy = hwProxyFactory_->createPresentationProxy();
+    shared_ptr<IdentityCredential> credential =
+            ndk::SharedRefBase::make<IdentityCredential>(hwProxy, credentialData);
+    auto ret = credential->initialize();
+    if (ret != IIdentityCredentialStore::STATUS_OK) {
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                int(ret), "Error initializing IdentityCredential"));
+    }
+    *outCredential = credential;
+    return ndk::ScopedAStatus::ok();
+}
+
+}  // namespace aidl::android::hardware::identity