/*
 * Copyright 2020, 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 ANDROID_HARDWARE_IDENTITY_SECUREHARDWAREPROXY_H
#define ANDROID_HARDWARE_IDENTITY_SECUREHARDWAREPROXY_H

#include <utils/RefBase.h>
#include <optional>
#include <string>
#include <utility>
#include <vector>

namespace android::hardware::identity {

using ::android::RefBase;
using ::std::optional;
using ::std::pair;
using ::std::string;
using ::std::vector;

// These classes are used to communicate with Secure Hardware. They mimic the
// API in libEmbeddedIC 1:1 (except for using C++ types) as each call is intended
// to be forwarded to the Secure Hardware.
//
// Instances are instantiated when a provisioning or presentation session
// starts. When the session is complete, the shutdown() method is called.
//

// Forward declare.
//
class SecureHardwareProvisioningProxy;
class SecureHardwareSessionProxy;
class SecureHardwarePresentationProxy;

// This is a class used to create proxies.
//
class SecureHardwareProxyFactory : public RefBase {
  public:
    SecureHardwareProxyFactory() {}
    virtual ~SecureHardwareProxyFactory() {}

    virtual sp<SecureHardwareProvisioningProxy> createProvisioningProxy() = 0;
    virtual sp<SecureHardwareSessionProxy> createSessionProxy() = 0;
    virtual sp<SecureHardwarePresentationProxy> createPresentationProxy() = 0;
};

// The proxy used for provisioning.
//
class SecureHardwareProvisioningProxy : public RefBase {
  public:
    SecureHardwareProvisioningProxy() {}
    virtual ~SecureHardwareProvisioningProxy() {}

    virtual bool initialize(bool testCredential) = 0;

    virtual bool initializeForUpdate(bool testCredential, const string& docType,
                                     const vector<uint8_t>& encryptedCredentialKeys) = 0;

    virtual optional<uint32_t> getId() = 0;

    virtual bool shutdown() = 0;

    // Returns public key certificate chain with attestation.
    //
    // This must return an entire certificate chain and its implementation must
    // be coordinated with the implementation of eicOpsCreateCredentialKey() on
    // the TA side (which may return just a single certificate or the entire
    // chain).
    virtual optional<vector<uint8_t>> createCredentialKey(const vector<uint8_t>& challenge,
                                                          const vector<uint8_t>& applicationId) = 0;

    // Returns public key certificate with a remotely provisioned attestation key.
    //
    // This returns a single certificate that is signed by the given |attestationKeyBlob|.
    // The implementation of eicOpsCreateCredentialKey() on the TA side must coordinate
    // with its corresponding keymint implementation to sign using the attestation key. The
    // |attestationKeyCert| parameter is the certificates for |attestationKeyBlob|,
    // formatted as concatenated, DER-encoded, X.509 certificates.
    virtual optional<vector<uint8_t>> createCredentialKeyUsingRkp(
            const vector<uint8_t>& challenge, const vector<uint8_t>& applicationId,
            const vector<uint8_t>& attestationKeyBlob,
            const vector<uint8_t>& attestationKeyCert) = 0;

    virtual bool startPersonalization(int accessControlProfileCount, const vector<int>& entryCounts,
                                      const string& docType,
                                      size_t expectedProofOfProvisioningSize) = 0;

    // Returns MAC (28 bytes).
    virtual optional<vector<uint8_t>> addAccessControlProfile(
            int id, const vector<uint8_t>& readerCertificate, bool userAuthenticationRequired,
            uint64_t timeoutMillis, uint64_t secureUserId) = 0;

    virtual bool beginAddEntry(const vector<int>& accessControlProfileIds, const string& nameSpace,
                               const string& name, uint64_t entrySize) = 0;

    // Returns encryptedContent.
    virtual optional<vector<uint8_t>> addEntryValue(const vector<int>& accessControlProfileIds,
                                                    const string& nameSpace, const string& name,
                                                    const vector<uint8_t>& content) = 0;

    // Returns signatureOfToBeSigned (EIC_ECDSA_P256_SIGNATURE_SIZE bytes).
    virtual optional<vector<uint8_t>> finishAddingEntries() = 0;

    // Returns encryptedCredentialKeys (80 bytes).
    virtual optional<vector<uint8_t>> finishGetCredentialData(const string& docType) = 0;
};

enum AccessCheckResult {
    kOk,
    kFailed,
    kNoAccessControlProfiles,
    kUserAuthenticationFailed,
    kReaderAuthenticationFailed,
};

// The proxy used for sessions.
//
class SecureHardwareSessionProxy : public RefBase {
  public:
    SecureHardwareSessionProxy() {}

    virtual ~SecureHardwareSessionProxy() {}

    virtual bool initialize() = 0;

    virtual optional<uint32_t> getId() = 0;

    virtual bool shutdown() = 0;

    virtual optional<uint64_t> getAuthChallenge() = 0;

    // Returns private key
    virtual optional<vector<uint8_t>> getEphemeralKeyPair() = 0;

    virtual bool setReaderEphemeralPublicKey(const vector<uint8_t>& readerEphemeralPublicKey) = 0;

    virtual bool setSessionTranscript(const vector<uint8_t>& sessionTranscript) = 0;
};

// The proxy used for presentation.
//
class SecureHardwarePresentationProxy : public RefBase {
  public:
    SecureHardwarePresentationProxy() {}
    virtual ~SecureHardwarePresentationProxy() {}

    virtual bool initialize(uint32_t sessionId, bool testCredential, const string& docType,
                            const vector<uint8_t>& encryptedCredentialKeys) = 0;

    virtual optional<uint32_t> getId() = 0;

    virtual bool shutdown() = 0;

    // Returns publicKeyCert (1st component) and signingKeyBlob (2nd component)
    virtual optional<pair<vector<uint8_t>, vector<uint8_t>>> generateSigningKeyPair(
            const string& docType, time_t now) = 0;

    // Returns private key
    virtual optional<vector<uint8_t>> createEphemeralKeyPair() = 0;

    virtual optional<uint64_t> createAuthChallenge() = 0;

    virtual bool startRetrieveEntries() = 0;

    virtual bool setAuthToken(uint64_t challenge, uint64_t secureUserId, uint64_t authenticatorId,
                              int hardwareAuthenticatorType, uint64_t timeStamp,
                              const vector<uint8_t>& mac, uint64_t verificationTokenChallenge,
                              uint64_t verificationTokenTimestamp,
                              int verificationTokenSecurityLevel,
                              const vector<uint8_t>& verificationTokenMac) = 0;

    virtual bool pushReaderCert(const vector<uint8_t>& certX509) = 0;

    virtual optional<bool> validateAccessControlProfile(int id,
                                                        const vector<uint8_t>& readerCertificate,
                                                        bool userAuthenticationRequired,
                                                        int timeoutMillis, uint64_t secureUserId,
                                                        const vector<uint8_t>& mac) = 0;

    virtual bool validateRequestMessage(const vector<uint8_t>& sessionTranscript,
                                        const vector<uint8_t>& requestMessage, int coseSignAlg,
                                        const vector<uint8_t>& readerSignatureOfToBeSigned) = 0;

    virtual bool prepareDeviceAuthentication(const vector<uint8_t>& sessionTranscript,
                                             const vector<uint8_t>& readerEphemeralPublicKey,
                                             const vector<uint8_t>& signingKeyBlob,
                                             const string& docType,
                                             unsigned int numNamespacesWithValues,
                                             size_t expectedDeviceNamespacesSize) = 0;

    virtual AccessCheckResult startRetrieveEntryValue(
            const string& nameSpace, const string& name, unsigned int newNamespaceNumEntries,
            int32_t entrySize, const vector<int32_t>& accessControlProfileIds) = 0;

    virtual optional<vector<uint8_t>> retrieveEntryValue(
            const vector<uint8_t>& encryptedContent, const string& nameSpace, const string& name,
            const vector<int32_t>& accessControlProfileIds) = 0;

    virtual optional<vector<uint8_t>> finishRetrieval();
    virtual optional<pair<vector<uint8_t>, vector<uint8_t>>> finishRetrievalWithSignature();

    virtual optional<vector<uint8_t>> deleteCredential(const string& docType,
                                                       const vector<uint8_t>& challenge,
                                                       bool includeChallenge,
                                                       size_t proofOfDeletionCborSize) = 0;

    virtual optional<vector<uint8_t>> proveOwnership(const string& docType, bool testCredential,
                                                     const vector<uint8_t>& challenge,
                                                     size_t proofOfOwnershipCborSize) = 0;
};

}  // namespace android::hardware::identity

#endif  // ANDROID_HARDWARE_IDENTITY_SECUREHARDWAREPROXY_H