Add credstore system daemon.

The credstore system daemon is sitting below the Identity Credential
Framework APIs and on top of the Identity Credential HALs. Its main
job is to store credential data and provide a way for applications to
communicate with the secure hardware abstracted by the HAL.

This daemon runs as an unprivileged user, credstore.

The auth-tokens needed by credstore are supplied by keystore and this
CL includes the requisite changes to keystore for this to work.

Bug: 111446262
Test: CTS tests for Framework APIs
Change-Id: Ieb4d59852a143482436a1c418c25ed96e25c0047
diff --git a/identity/Credential.h b/identity/Credential.h
new file mode 100644
index 0000000..356d75f
--- /dev/null
+++ b/identity/Credential.h
@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 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.
+ */
+
+#ifndef SYSTEM_SECURITY_CREDENTIAL_H_
+#define SYSTEM_SECURITY_CREDENTIAL_H_
+
+#include <string>
+#include <vector>
+
+#include <android/security/identity/BnCredential.h>
+
+#include <android/hardware/identity/1.0/IIdentityCredentialStore.h>
+#include <android/hardware/identity/1.0/types.h>
+
+#include "CredentialData.h"
+
+namespace android {
+namespace security {
+namespace identity {
+
+using ::android::sp;
+using ::android::binder::Status;
+using ::std::string;
+using ::std::vector;
+
+using ::android::hardware::identity::V1_0::IIdentityCredential;
+using ::android::hardware::identity::V1_0::IIdentityCredentialStore;
+
+class Credential : public BnCredential {
+  public:
+    Credential(const string& dataPath, const string& credentialName);
+    ~Credential();
+
+    Status loadCredential(sp<IIdentityCredentialStore> halStoreBinder);
+
+    // ICredential overrides
+    Status createEphemeralKeyPair(vector<uint8_t>* _aidl_return) override;
+
+    Status setReaderEphemeralPublicKey(const vector<uint8_t>& publicKey) override;
+
+    Status deleteCredential(vector<uint8_t>* _aidl_return) override;
+
+    Status getCredentialKeyCertificateChain(vector<uint8_t>* _aidl_return) override;
+
+    Status selectAuthKey(bool allowUsingExhaustedKeys, int64_t* _aidl_return) override;
+
+    Status getEntries(const vector<uint8_t>& requestMessage,
+                      const vector<RequestNamespaceParcel>& requestNamespaces,
+                      const vector<uint8_t>& sessionTranscript,
+                      const vector<uint8_t>& readerSignature, bool allowUsingExhaustedKeys,
+                      GetEntriesResultParcel* _aidl_return) override;
+
+    Status setAvailableAuthenticationKeys(int32_t keyCount, int32_t maxUsesPerKey) override;
+    Status getAuthKeysNeedingCertification(vector<AuthKeyParcel>* _aidl_return) override;
+    Status storeStaticAuthenticationData(const AuthKeyParcel& authenticationKey,
+                                         const vector<uint8_t>& staticAuthData) override;
+    Status getAuthenticationDataUsageCount(vector<int32_t>* _aidl_return) override;
+
+  private:
+    string dataPath_;
+    string credentialName_;
+
+    const AuthKeyData* selectedAuthKey_ = nullptr;
+    uint64_t selectedChallenge_ = 0;
+
+    sp<CredentialData> data_;
+
+    sp<IIdentityCredential> halBinder_;
+};
+
+}  // namespace identity
+}  // namespace security
+}  // namespace android
+
+#endif  // SYSTEM_SECURITY_IDENTITY_CREDENTIAL_H_