/*
 * Copyright 2017, 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 "KeymasterDevice.h"
#include "buffer.h"
#include "export_key.h"
#include "certs.h"
#include "import_key.h"
#include "import_wrapped_key.h"
#include "proto_utils.h"

#include <Keymaster.client.h>
#include <nos/debug.h>
#include <nos/NuggetClient.h>

#include <keymasterV4_0/key_param_output.h>

#include <android-base/logging.h>
#include <android-base/properties.h>

#include <algorithm>

#include <time.h>

namespace android {
namespace hardware {
namespace keymaster {

namespace {

constexpr char PROPERTY_OS_VERSION[] = "ro.build.version.release";
constexpr char PROPERTY_OS_PATCHLEVEL[] = "ro.build.version.security_patch";
constexpr char PROPERTY_VENDOR_PATCHLEVEL[] = "ro.vendor.build.security_patch";

std::string DigitsOnly(const std::string& code) {
    // Keep digits only.
    std::string filtered_code;
    std::copy_if(code.begin(), code.end(), std::back_inserter(filtered_code),
                 isdigit);
    return filtered_code;
}

/** Get one version number from a string and move loc to the point after the
 * next version delimiter.
 */
uint32_t ExtractVersion(const std::string& version, size_t* loc) {
    if (*loc == std::string::npos || *loc >= version.size()) {
        return 0;
    }

    uint32_t value = 0;
    size_t new_loc = version.find('.', *loc);
    if (new_loc == std::string::npos) {
        auto sanitized = DigitsOnly(version.substr(*loc));
        if (!sanitized.empty()) {
            if (sanitized.size() < version.size() - *loc) {
                LOG(ERROR) << "Unexpected version format: \"" << version
                           << "\"";
            }
            value = std::stoi(sanitized);
        }
        *loc = new_loc;
    } else {
        auto sanitized = DigitsOnly(version.substr(*loc, new_loc - *loc));
        if (!sanitized.empty()) {
            if (sanitized.size() < new_loc - *loc) {
                LOG(ERROR) << "Unexpected version format: \"" << version
                           << "\"";
            }
            value = std::stoi(sanitized);
        }
        *loc = new_loc + 1;
    }
    return value;
}

uint32_t VersionToUint32(const std::string& version) {
    size_t loc = 0;
    uint32_t major = ExtractVersion(version, &loc);
    uint32_t minor = ExtractVersion(version, &loc);
    uint32_t subminor = ExtractVersion(version, &loc);
    return major * 10000 + minor * 100 + subminor;
}

uint32_t DateCodeToUint32(const std::string& code, bool include_day) {
    // Keep digits only.
    std::string filtered_code = DigitsOnly(code);

    // Return 0 if the date string has an unexpected number of digits.
    uint32_t return_value = 0;
    if (filtered_code.size() == 8) {
        return_value = std::stoi(filtered_code);
        if (!include_day) {
            return_value /= 100;
        }
    } else if (filtered_code.size() == 6) {
        return_value = std::stoi(filtered_code);
        if (include_day) {
            return_value *= 100;
        }
    } else {
        LOG(ERROR) << "Unexpected patchset format: \"" << code << "\"";
    }
    return return_value;
}

// Helper class to call a finalizer on stack unwind.
class Finalize {
 private:
    std::function<void()> f_;

 public:
    Finalize(std::function<void()> f) : f_(f) {}
    ~Finalize() { if (f_) f_(); }
    void release() { f_ = {}; }
};

}  // namespace

// std
using std::string;

// base
using ::android::base::GetProperty;
using ::android::base::WaitForPropertyCreation;

// libhidl
using ::android::hardware::Void;

// HAL
using ::android::hardware::keymaster::V4_0::Algorithm;
using ::android::hardware::keymaster::V4_0::KeyCharacteristics;
using ::android::hardware::keymaster::V4_0::KeyFormat;
using ::android::hardware::keymaster::V4_0::HardwareAuthToken;
using ::android::hardware::keymaster::V4_0::HardwareAuthenticatorType;
using ::android::hardware::keymaster::V4_0::SecurityLevel;
using ::android::hardware::keymaster::V4_0::Tag;

// nos
using nos::NuggetClient;

// Keymaster app
// KM 3.0 types
using ::nugget::app::keymaster::AddRngEntropyRequest;
using ::nugget::app::keymaster::AddRngEntropyResponse;
using ::nugget::app::keymaster::GenerateKeyRequest;
using ::nugget::app::keymaster::GenerateKeyResponse;
using ::nugget::app::keymaster::GetKeyCharacteristicsRequest;
using ::nugget::app::keymaster::GetKeyCharacteristicsResponse;
using ::nugget::app::keymaster::ImportKeyRequest;
using ::nugget::app::keymaster::ImportKeyResponse;
using ::nugget::app::keymaster::ExportKeyRequest;
using ::nugget::app::keymaster::ExportKeyResponse;
using ::nugget::app::keymaster::StartAttestKeyRequest;
using ::nugget::app::keymaster::StartAttestKeyResponse;
using ::nugget::app::keymaster::ContinueAttestKeyRequest;
using ::nugget::app::keymaster::ContinueAttestKeyResponse;
using ::nugget::app::keymaster::FinishAttestKeyRequest;
using ::nugget::app::keymaster::FinishAttestKeyResponse;
using ::nugget::app::keymaster::UpgradeKeyRequest;
using ::nugget::app::keymaster::UpgradeKeyResponse;
using ::nugget::app::keymaster::DeleteKeyRequest;
using ::nugget::app::keymaster::DeleteKeyResponse;
using ::nugget::app::keymaster::DeleteAllKeysRequest;
using ::nugget::app::keymaster::DeleteAllKeysResponse;
using ::nugget::app::keymaster::DestroyAttestationIdsRequest;
using ::nugget::app::keymaster::DestroyAttestationIdsResponse;
using ::nugget::app::keymaster::BeginOperationRequest;
using ::nugget::app::keymaster::BeginOperationResponse;
using ::nugget::app::keymaster::UpdateOperationRequest;
using ::nugget::app::keymaster::UpdateOperationResponse;
using ::nugget::app::keymaster::FinishOperationRequest;
using ::nugget::app::keymaster::FinishOperationResponse;
using ::nugget::app::keymaster::AbortOperationRequest;
using ::nugget::app::keymaster::AbortOperationResponse;
using ::nugget::app::keymaster::ComputeSharedHmacRequest;
using ::nugget::app::keymaster::ComputeSharedHmacResponse;
using ::nugget::app::keymaster::GetHmacSharingParametersRequest;
using ::nugget::app::keymaster::GetHmacSharingParametersResponse;
using ::nugget::app::keymaster::SetSystemVersionInfoRequest;
using ::nugget::app::keymaster::SetSystemVersionInfoResponse;
using ::nugget::app::keymaster::GetBootInfoRequest;
using ::nugget::app::keymaster::GetBootInfoResponse;

// KM 4.0 types
using ::nugget::app::keymaster::ImportWrappedKeyRequest;
namespace nosapp = ::nugget::app::keymaster;

// KM internal types
using ::nugget::app::keymaster::AttestationSelector;

static ErrorCode status_to_error_code(uint32_t status)
{
    switch (status) {
    case APP_SUCCESS:
        return ErrorCode::OK;
        break;
    case APP_ERROR_BOGUS_ARGS:
        return ErrorCode::INVALID_ARGUMENT;
        break;
    case APP_ERROR_INTERNAL:
        return ErrorCode::UNKNOWN_ERROR;
        break;
    case APP_ERROR_TOO_MUCH:
        return ErrorCode::INSUFFICIENT_BUFFER_SPACE;
        break;
    case APP_ERROR_RPC:
        return ErrorCode::SECURE_HW_COMMUNICATION_FAILED;
        break;
    // TODO: app specific error codes go here.
    default:
        return ErrorCode::UNKNOWN_ERROR;
        break;
    }
}

#define KM_CALL(meth, request, response) {                                    \
    const uint32_t status = _keymaster. meth (request, &response);            \
    const ErrorCode error_code = translate_error_code(response.error_code()); \
    if (status != APP_SUCCESS) {                                              \
        LOG(ERROR) << #meth << " : request failed with status: "              \
                   << nos::StatusCodeString(status);                          \
        return status_to_error_code(status);                                  \
    }                                                                         \
    if (error_code != ErrorCode::OK) {                                        \
        LOG(ERROR) << #meth << " : device response error code: "              \
                   << error_code;                                             \
        return error_code;                                                    \
    }                                                                         \
}

#define KM_CALLV(meth, request, response, ...) {                              \
    const uint32_t status = _keymaster. meth (request, &response);            \
    const ErrorCode error_code = translate_error_code(response.error_code()); \
    if (status != APP_SUCCESS) {                                              \
        LOG(ERROR) << #meth << " : request failed with status: "              \
                   << nos::StatusCodeString(status);                          \
        _hidl_cb(status_to_error_code(status), __VA_ARGS__);                  \
        return Void();                                                        \
    }                                                                         \
    if (error_code != ErrorCode::OK) {                                        \
        LOG(ERROR) << #meth << " : device response error code: "              \
                   << error_code;                                             \
        _hidl_cb(error_code, __VA_ARGS__);                                    \
        return Void();                                                        \
    }                                                                         \
}

// Methods from ::android::hardware::keymaster::V3_0::IKeymasterDevice follow.

KeymasterDevice::KeymasterDevice(KeymasterClient& keymaster) :
        _keymaster{keymaster} {
    // Block until all of the properties have been created
    while (!(WaitForPropertyCreation(PROPERTY_OS_VERSION) &&
             WaitForPropertyCreation(PROPERTY_OS_PATCHLEVEL) &&
             WaitForPropertyCreation(PROPERTY_VENDOR_PATCHLEVEL))) {}

    _os_version = VersionToUint32(GetProperty(PROPERTY_OS_VERSION, ""));
    _os_patchlevel = DateCodeToUint32(GetProperty(PROPERTY_OS_PATCHLEVEL, ""),
                                     false /* include_day */);
    _vendor_patchlevel = DateCodeToUint32(
            GetProperty(PROPERTY_VENDOR_PATCHLEVEL, ""),
            true /* include_day */);

    SendSystemVersionInfo();
    GetBootInfo();
}

Return<void> KeymasterDevice::getHardwareInfo(
        getHardwareInfo_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::getHardwareInfo";

    (void)_keymaster;
    _hidl_cb(SecurityLevel::STRONGBOX,
             string("CitadelKeymaster"), string("Google"));

    return Void();
}

Return<void> KeymasterDevice::getHmacSharingParameters(
    getHmacSharingParameters_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::getHmacSharingParameters";

    GetHmacSharingParametersRequest request;
    GetHmacSharingParametersResponse response;
    HmacSharingParameters result;

    KM_CALLV(GetHmacSharingParameters, request, response, result);

    ErrorCode ec = translate_error_code(response.error_code());

    if (ec != ErrorCode::OK) {
        _hidl_cb(ec, HmacSharingParameters());
    }

    const std::string & nonce = response.hmac_sharing_params().nonce();
    const std::string & seed = response.hmac_sharing_params().seed();

    if (seed.size() == 32) {
        result.seed.setToExternal(reinterpret_cast<uint8_t*>(
                const_cast<char*>(seed.data())),
                seed.size(), false);
    } else if (seed.size() != 0) {
        LOG(ERROR) << "Citadel returned unexpected seed size: "
                << seed.size();
        _hidl_cb(ErrorCode::UNKNOWN_ERROR, HmacSharingParameters());
        return Void();
    }

    if (nonce.size() == result.nonce.size()) {
        std::copy(nonce.begin(), nonce.end(), result.nonce.data());
    } else {
        LOG(ERROR) << "Citadel returned unexpected nonce size: "
                << nonce.size();
        _hidl_cb(ErrorCode::UNKNOWN_ERROR, HmacSharingParameters());
        return Void();
    }

    _hidl_cb(ec, result);

    return Void();
}

Return<void> KeymasterDevice::computeSharedHmac(
    const hidl_vec<HmacSharingParameters>& params,
    computeSharedHmac_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::computeSharedHmac";

    ComputeSharedHmacRequest request;
    ComputeSharedHmacResponse response;
    hidl_vec<uint8_t> result;

    for (const HmacSharingParameters & param : params) {
        // TODO respect max number of parameters defined in
        // keymaster_types.proto
        nosapp::HmacSharingParameters* req_param =
                request.add_hmac_sharing_params();
        req_param->set_nonce(
                reinterpret_cast<const int8_t*>(
                param.nonce.data()), param.nonce.size());
        req_param->set_seed(reinterpret_cast<const int8_t*>(param.seed.data()),
                param.seed.size());
    }

    KM_CALLV(ComputeSharedHmac, request, response, result);

    ErrorCode ec = translate_error_code(response.error_code());

    if (ec != ErrorCode::OK) {
        _hidl_cb(ec, result);
        return Void();
    }

    const std::string & share_check = response.sharing_check();

    result.setToExternal(reinterpret_cast<uint8_t*>(
            const_cast<char*>(share_check.data())), share_check.size(), false);
    _hidl_cb(ec, result);

    return Void();
}

Return<void> KeymasterDevice::verifyAuthorization(
    uint64_t operationHandle, const hidl_vec<KeyParameter>& parametersToVerify,
    const HardwareAuthToken& authToken, verifyAuthorization_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::verifyAuthorization";

    (void)operationHandle;
    (void)parametersToVerify;
    (void)authToken;

    (void)_keymaster;
    _hidl_cb(ErrorCode::UNIMPLEMENTED, VerificationToken());

    return Void();
}

Return<ErrorCode> KeymasterDevice::addRngEntropy(const hidl_vec<uint8_t>& data)
{
    LOG(VERBOSE) << "Running KeymasterDevice::addRngEntropy";

    if (!data.size()) return ErrorCode::OK;

    const size_t chunk_size = 1024;
    for (size_t i = 0; i < data.size(); i += chunk_size) {
        AddRngEntropyRequest request;
        AddRngEntropyResponse response;

        request.set_data(&data[i], std::min(chunk_size, data.size() - i));

        // Call device.
        KM_CALL(AddRngEntropy, request, response);
    }

    return ErrorCode::OK;
}

Return<void> KeymasterDevice::generateKey(
        const hidl_vec<KeyParameter>& keyParams,
        generateKey_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::generateKey";

    GenerateKeyRequest request;
    GenerateKeyResponse response;

    hidl_vec<uint8_t> blob;
    KeyCharacteristics characteristics;
    if (hidl_params_to_pb(
            keyParams, request.mutable_params()) != ErrorCode::OK) {
      _hidl_cb(ErrorCode::INVALID_ARGUMENT, blob, characteristics);
      return Void();
    }

    // Call device.
    KM_CALLV(GenerateKey, request, response,
             hidl_vec<uint8_t>{}, KeyCharacteristics());

    blob.setToExternal(
        reinterpret_cast<uint8_t*>(
            const_cast<char*>(response.blob().blob().data())),
        response.blob().blob().size(), false);
    pb_to_hidl_params(response.characteristics().software_enforced(),
                      &characteristics.softwareEnforced);
    pb_to_hidl_params(response.characteristics().tee_enforced(),
                      &characteristics.hardwareEnforced);

    _hidl_cb(translate_error_code(response.error_code()),
             blob, characteristics);
    return Void();
}

Return<void> KeymasterDevice::getKeyCharacteristics(
        const hidl_vec<uint8_t>& keyBlob,
        const hidl_vec<uint8_t>& clientId,
        const hidl_vec<uint8_t>& appData,
        getKeyCharacteristics_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::getKeyCharacteristics";

    GetKeyCharacteristicsRequest request;
    GetKeyCharacteristicsResponse response;

    request.mutable_blob()->set_blob(&keyBlob[0], keyBlob.size());
    request.set_client_id(&clientId[0], clientId.size());
    request.set_app_data(&appData[0], appData.size());

    // Call device.
    KM_CALLV(GetKeyCharacteristics, request, response, KeyCharacteristics());

    KeyCharacteristics characteristics;
    pb_to_hidl_params(response.characteristics().software_enforced(),
                      &characteristics.softwareEnforced);
    pb_to_hidl_params(response.characteristics().tee_enforced(),
                      &characteristics.hardwareEnforced);

    _hidl_cb(translate_error_code(response.error_code()), characteristics);
    return Void();
}

Return<void> KeymasterDevice::importKey(
        const hidl_vec<KeyParameter>& params, KeyFormat keyFormat,
        const hidl_vec<uint8_t>& keyData, importKey_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::importKey";

    ErrorCode error;
    ImportKeyRequest request;
    ImportKeyResponse response;

    error = import_key_request(params, keyFormat, keyData, &request);
    if (error != ErrorCode::OK) {
        LOG(ERROR) << "ImportKey request parsing failed with error "
                   << error;
        _hidl_cb(error, hidl_vec<uint8_t>{}, KeyCharacteristics{});
        return Void();
    }

    KM_CALLV(ImportKey, request, response,
             hidl_vec<uint8_t>{}, KeyCharacteristics{});

    hidl_vec<uint8_t> blob;
    blob.setToExternal(
        reinterpret_cast<uint8_t*>(
            const_cast<char*>(response.blob().blob().data())),
        response.blob().blob().size(), false);

    KeyCharacteristics characteristics;
    pb_to_hidl_params(response.characteristics().software_enforced(),
                      &characteristics.softwareEnforced);
    error = pb_to_hidl_params(response.characteristics().tee_enforced(),
                              &characteristics.hardwareEnforced);
    if (error != ErrorCode::OK) {
        LOG(ERROR) << "KeymasterDevice::importKey: response tee_enforced :"
                   << error;
        _hidl_cb(error, hidl_vec<uint8_t>{}, KeyCharacteristics{});
        return Void();
    }

    _hidl_cb(ErrorCode::OK, blob, characteristics);
    return Void();
}

Return<void> KeymasterDevice::exportKey(
        KeyFormat exportFormat, const hidl_vec<uint8_t>& keyBlob,
        const hidl_vec<uint8_t>& clientId,
        const hidl_vec<uint8_t>& appData, exportKey_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::exportKey";

    ExportKeyRequest request;
    ExportKeyResponse response;

    request.set_format((::nugget::app::keymaster::KeyFormat)exportFormat);
    request.mutable_blob()->set_blob(&keyBlob[0], keyBlob.size());
    request.set_client_id(&clientId[0], clientId.size());
    request.set_app_data(&appData[0], appData.size());

    KM_CALLV(ExportKey, request, response, hidl_vec<uint8_t>{});

    hidl_vec<uint8_t> der;
    ErrorCode error_code = export_key_der(response, &der);
    if (error_code != ErrorCode::OK) {
        LOG(ERROR) << "KeymasterDevice::exportKey: DER conversion failed: "
                   << error_code;
        _hidl_cb(error_code, hidl_vec<uint8_t>{});
        return Void();
    }

    _hidl_cb(error_code, der);
    return Void();
}

#define ATTESTATION_APPLICATION_ID_MAX_SIZE 1024
#define UTCTIME_STR_WITH_NUL_SIZE           14
static size_t integer_size(uint64_t value)
{
        size_t octet_count = 1;
        for (value >>= 8; value; value >>= 8) {
                octet_count++;
        }
        return octet_count;
}
static size_t encoded_length_size(size_t length)
{
        if (length < 0x80) {
                return 1;
        }
        return integer_size(length) + 1;
}

static uint8_t *asn1_encode_length(size_t length, const uint8_t *head, uint8_t *tail)
{
        if (!tail || tail < head + encoded_length_size(length)) {
                return NULL;
        }

        if (length < 0x80) {
                // Short length case
                *(--tail) = length;
        } else {
                // Encode length
                uint8_t length_len;
                uint8_t *orig_tail = tail;
                do {
                        *(--tail) = length & 0xFF;
                        length >>= 8;
                } while (length);

                // Encode length of length.  Assumes length < pow(128, 127).
                // Should be good.
                length_len = (orig_tail - tail);
                *(--tail) = 0x80 | length_len;
        }
        return tail;
}

Return<void> KeymasterDevice::attestKey(
        const hidl_vec<uint8_t>& keyToAttest,
        const hidl_vec<KeyParameter>& attestParams,
        attestKey_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::attestKey";

    StartAttestKeyRequest startRequest;
    StartAttestKeyResponse startResponse;

    // Ensure that required parameters are present.
    tag_map_t attest_tag_map;
    if (hidl_params_to_map(attestParams, &attest_tag_map) != ErrorCode::OK) {
        _hidl_cb(ErrorCode::INVALID_ARGUMENT, hidl_vec<hidl_vec<uint8_t> >{});
      return Void();
    }
    if (attest_tag_map.find(Tag::ATTESTATION_APPLICATION_ID) ==
        attest_tag_map.end()) {
        _hidl_cb(ErrorCode::ATTESTATION_APPLICATION_ID_MISSING,
                 hidl_vec<hidl_vec<uint8_t> >{});
      return Void();
    }

    hidl_vec<uint8_t> client_id;
    if (attest_tag_map.find(Tag::APPLICATION_ID) != attest_tag_map.end()) {
        client_id = attest_tag_map.find(Tag::APPLICATION_ID)->second[0].blob;
    }
    hidl_vec<uint8_t> app_data;
    if (attest_tag_map.find(Tag::APPLICATION_DATA) != attest_tag_map.end()) {
        app_data = attest_tag_map.find(
            Tag::APPLICATION_DATA)->second[0].blob;
    }

    GetKeyCharacteristicsRequest charRequest;
    GetKeyCharacteristicsResponse charResponse;

    charRequest.mutable_blob()->set_blob(&keyToAttest[0], keyToAttest.size());
    charRequest.set_client_id(&client_id[0], client_id.size());
    charRequest.set_app_data(&app_data[0], app_data.size());

    // Call device.
    KM_CALLV(GetKeyCharacteristics, charRequest,
             charResponse, hidl_vec<hidl_vec<uint8_t> >{});

    KeyCharacteristics characteristics;
    pb_to_hidl_params(charResponse.characteristics().software_enforced(),
                      &characteristics.softwareEnforced);
    pb_to_hidl_params(charResponse.characteristics().tee_enforced(),
                      &characteristics.hardwareEnforced);

    tag_map_t char_tag_map;
    if (hidl_params_to_map(characteristics.softwareEnforced,
                           &attest_tag_map) != ErrorCode::OK) {
        _hidl_cb(ErrorCode::INVALID_ARGUMENT, hidl_vec<hidl_vec<uint8_t> >{});
      return Void();
    }

    time_t not_before = 0;
    if (char_tag_map.find(Tag::ACTIVE_DATETIME) != char_tag_map.end()) {
        not_before = char_tag_map.find(
            Tag::ACTIVE_DATETIME)->second[0].f.dateTime;
    } else if (char_tag_map.find(Tag::CREATION_DATETIME) !=
               char_tag_map.end()) {
        not_before = char_tag_map.find(
            Tag::CREATION_DATETIME)->second[0].f.dateTime;
    }
    // TODO: else: both ACTIVE and CREATION datetime are absent, is
    // this an error?
    time_t not_after = 0;
    if (char_tag_map.find(Tag::USAGE_EXPIRE_DATETIME) != char_tag_map.end()) {
        not_after = char_tag_map.find(
            Tag::USAGE_EXPIRE_DATETIME)->second[0].f.dateTime;
    } else {
        not_after = 1842739199; // Batch cert expiry date: 2028-05-23:23:59:59.
    }

    char not_before_str[UTCTIME_STR_WITH_NUL_SIZE] = {};
    char not_after_str[UTCTIME_STR_WITH_NUL_SIZE] = {};
    if (::strftime(not_before_str, sizeof(not_before_str),
                   "%y%m%d%H%M%SZ", gmtime(&not_before)) == 0 ||
        ::strftime(not_after_str, sizeof(not_after_str),
                   "%y%m%d%H%M%SZ", gmtime(&not_after)) == 0) {
        _hidl_cb(ErrorCode::UNKNOWN_ERROR, hidl_vec<hidl_vec<uint8_t> >{});
    }

    startRequest.mutable_blob()->set_blob(&keyToAttest[0], keyToAttest.size());
    if (hidl_params_to_pb(
            attestParams, startRequest.mutable_params()) != ErrorCode::OK) {
      _hidl_cb(ErrorCode::INVALID_ARGUMENT, hidl_vec<hidl_vec<uint8_t> >{});
      return Void();
    }

    // Developer configs (i.e. nodelocked-RO), and PROTO devices will
    // fall back to TEST certs here, since BATCH certs will be
    // unavailable.  The selected certificate may be determined via
    // info included in the response to FinishAttestKeyRequest().
    startRequest.set_selector(AttestationSelector::ATTEST_BATCH);

    startRequest.set_not_before(not_before_str,
                                sizeof(not_before_str) - 1);
    startRequest.set_not_after(not_after_str,
                                sizeof(not_after_str) - 1);

    // TODO: as an optimization, avoid sending the
    // ATTESTATION_APPLICATION_ID to Start, since only the length of
    // this field is needed at this stage.
    // NOTE: citadel adds the AAID to the hash in the prologue for now. So if this
    // is ever changes the HASH_update call needs to move in the citadel firmware.

    KM_CALLV(StartAttestKey, startRequest, startResponse,
             hidl_vec<hidl_vec<uint8_t> >{});

    uint64_t operationHandle = startResponse.handle().handle();
    ContinueAttestKeyRequest continueRequest;
    ContinueAttestKeyResponse continueResponse;
    // Prepare to abort the pending operation in event of an error.
    Finalize finalize([&] () { abort(operationHandle); });

    continueRequest.mutable_handle()->set_handle(operationHandle);
    if (hidl_params_to_pb(
            attestParams, continueRequest.mutable_params()) != ErrorCode::OK) {
        LOG(ERROR) << "Failed to parse attest params";
        _hidl_cb(ErrorCode::INVALID_ARGUMENT, hidl_vec<hidl_vec<uint8_t> >{});
        return Void();
    }

    KM_CALLV(ContinueAttestKey, continueRequest, continueResponse,
             hidl_vec<hidl_vec<uint8_t> >{});

    FinishAttestKeyRequest finishRequest;
    FinishAttestKeyResponse finishResponse;

    finishRequest.mutable_handle()->set_handle(operationHandle);

    KM_CALLV(FinishAttestKey, finishRequest, finishResponse,
             hidl_vec<hidl_vec<uint8_t> >{});

    hidl_vec<uint8_t>& attestation_application_id =
            attest_tag_map[Tag::ATTESTATION_APPLICATION_ID].begin()->blob;
    size_t cert_len = startResponse.certificate_prologue().size()
                    + attestation_application_id.size()
                    + continueResponse.certificate_body().size()
                    + finishResponse.certificate_epilogue().size();

    std::stringstream ss;
    {
        char c = 0x30;
        ss.write(&c, 1); // DER_SEQUENCE | DER_CONSTRUCTED

        uint8_t buffer[10];
        auto * cert_header = asn1_encode_length(cert_len, buffer, buffer + sizeof(buffer));

        if (cert_header == nullptr) {
            LOG(ERROR) << "Failed to generate attestation certificate sequence header";
            _hidl_cb(ErrorCode::UNKNOWN_ERROR, hidl_vec<hidl_vec<uint8_t> >{});
            return Void();
        }
        ss.write(reinterpret_cast<char*>(cert_header), buffer + sizeof(buffer) - cert_header);
    }

    ss << startResponse.certificate_prologue();
    ss.write(reinterpret_cast<const std::stringstream::char_type*>(
            attestation_application_id.data()), attestation_application_id.size());
    ss << continueResponse.certificate_body();
    ss << finishResponse.certificate_epilogue();

    if (!ss) {
        LOG(ERROR) << "Failed to generate attestation certificate";
        _hidl_cb(ErrorCode::UNKNOWN_ERROR, hidl_vec<hidl_vec<uint8_t> >{});
        return Void();
    }

    vector<hidl_vec<uint8_t> > chain;
    {
        hidl_vec<uint8_t> attestation_certificate;
        attestation_certificate.setToExternal(
            reinterpret_cast<uint8_t*>(
                const_cast<char*>(ss.str().data())),
            ss.str().size(), false);


        chain.push_back(std::move(attestation_certificate));

        hidl_vec<uint8_t> batch_cert;
        hidl_vec<uint8_t> intermediate_cert;
        hidl_vec<uint8_t> root;

        for (const KeyParameter &param : characteristics.hardwareEnforced) {
            if (param.tag != Tag::ALGORITHM) {
                continue;
            }

            // Node-locked RO implies that factory provisioned certs
            // (if any), are inaccessible, so fallback to the TEST
            // certs.  Similarly, PROTO chips were not provisioned
            // with certs, and hence will fallback to TEST certs.
            if (finishResponse.nodelocked_ro() ||
                finishResponse.chip_fusing() == nosapp::FUSING_PROTO) {
                if (param.f.algorithm == Algorithm::RSA) {
                    batch_cert.setToExternal(
                        const_cast<uint8_t*>(
                            TEST_BATCH_RSA_CERT),
                                      sizeof(TEST_BATCH_RSA_CERT));
                    intermediate_cert.setToExternal(
                        const_cast<uint8_t*>(
                            TEST_BATCH_RSA_INT_CERT),
                        sizeof(TEST_BATCH_RSA_INT_CERT));
                    root.setToExternal(
                        const_cast<uint8_t*>(
                            TEST_BATCH_ROOT_CERT),
                        sizeof(TEST_BATCH_ROOT_CERT));
                } else {
                    batch_cert.setToExternal(
                        const_cast<uint8_t*>(
                            TEST_BATCH_EC_CERT),
                        sizeof(TEST_BATCH_EC_CERT));
                    intermediate_cert.setToExternal(
                        const_cast<uint8_t*>(
                            TEST_BATCH_EC_INT_CERT),
                        sizeof(TEST_BATCH_EC_INT_CERT));
                    root.setToExternal(
                        const_cast<uint8_t*>(
                            TEST_BATCH_ROOT_CERT),
                        sizeof(TEST_BATCH_ROOT_CERT));
                }
            } else if (finishResponse.chip_fusing() == nosapp::FUSING_DVT) {
                if (param.f.algorithm == Algorithm::RSA) {
                    batch_cert.setToExternal(
                        const_cast<uint8_t*>(DEV_BATCH_RSA_CERT),
                        sizeof(DEV_BATCH_RSA_CERT));
                    intermediate_cert.setToExternal(
                        const_cast<uint8_t*>(DEV_BATCH_RSA_INT_CERT),
                        sizeof(DEV_BATCH_RSA_INT_CERT));
                } else {
                    batch_cert.setToExternal(
                        const_cast<uint8_t*>(DEV_BATCH_EC_CERT),
                        sizeof(DEV_BATCH_EC_CERT));
                    intermediate_cert.setToExternal(
                        const_cast<uint8_t*>(DEV_BATCH_EC_INT_CERT),
                        sizeof(DEV_BATCH_EC_INT_CERT));
                }
                root.setToExternal(
                    const_cast<uint8_t*>(DEV_BATCH_ROOT_CERT),
                    sizeof(DEV_BATCH_ROOT_CERT));
            } else {  // PVT!
                if (param.f.algorithm == Algorithm::RSA) {
                    batch_cert.setToExternal(
                        const_cast<uint8_t*>(PROD_BATCH_RSA_CERT),
                        sizeof(PROD_BATCH_RSA_CERT));
                    intermediate_cert.setToExternal(
                        const_cast<uint8_t*>(PROD_BATCH_RSA_INT_CERT),
                        sizeof(PROD_BATCH_RSA_INT_CERT));
                } else {
                    batch_cert.setToExternal(
                        const_cast<uint8_t*>(PROD_BATCH_EC_CERT),
                        sizeof(PROD_BATCH_EC_CERT));
                    intermediate_cert.setToExternal(
                        const_cast<uint8_t*>(PROD_BATCH_EC_INT_CERT),
                        sizeof(PROD_BATCH_EC_INT_CERT));
                }
                root.setToExternal(
                    const_cast<uint8_t*>(PROD_BATCH_ROOT_CERT),
                    sizeof(PROD_BATCH_ROOT_CERT));
            }
            break; // we found the ALGORITM tag so we can break the loop
        }

        chain.push_back(std::move(batch_cert));
        chain.push_back(std::move(intermediate_cert));
        chain.push_back(std::move(root));
    }

    _hidl_cb(ErrorCode::OK, chain);
    finalize.release();
    return Void();
}

Return<void> KeymasterDevice::upgradeKey(
        const hidl_vec<uint8_t>& keyBlobToUpgrade,
        const hidl_vec<KeyParameter>& upgradeParams,
        upgradeKey_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::upgradeKey";

    UpgradeKeyRequest request;
    UpgradeKeyResponse response;

    request.mutable_blob()->set_blob(&keyBlobToUpgrade[0],
                                     keyBlobToUpgrade.size());

    hidl_vec<uint8_t> blob;
    if (hidl_params_to_pb(
            upgradeParams, request.mutable_params()) != ErrorCode::OK) {
      _hidl_cb(ErrorCode::INVALID_ARGUMENT, blob);
      return Void();
    }

    KM_CALLV(UpgradeKey, request, response, hidl_vec<uint8_t>{});

    blob.setToExternal(
        reinterpret_cast<uint8_t*>(
            const_cast<char*>(response.blob().blob().data())),
        response.blob().blob().size(), false);

    _hidl_cb(translate_error_code(response.error_code()), blob);
    return Void();
}

Return<ErrorCode> KeymasterDevice::deleteKey(const hidl_vec<uint8_t>& keyBlob)
{
    LOG(VERBOSE) << "Running KeymasterDevice::deleteKey";

    DeleteKeyRequest request;
    DeleteKeyResponse response;

    request.mutable_blob()->set_blob(&keyBlob[0], keyBlob.size());

    KM_CALL(DeleteKey, request, response);

    return translate_error_code(response.error_code());
}

Return<ErrorCode> KeymasterDevice::deleteAllKeys()
{
    LOG(VERBOSE) << "Running KeymasterDevice::deleteAllKeys";

    DeleteAllKeysRequest request;
    DeleteAllKeysResponse response;

    KM_CALL(DeleteAllKeys, request, response);

    return translate_error_code(response.error_code());
}

Return<ErrorCode> KeymasterDevice::destroyAttestationIds()
{
    LOG(VERBOSE) << "Running KeymasterDevice::destroyAttestationIds";

    DestroyAttestationIdsRequest request;
    DestroyAttestationIdsResponse response;

    KM_CALL(DestroyAttestationIds, request, response);

    return translate_error_code(response.error_code());
}

Return<void> KeymasterDevice::begin(
        KeyPurpose purpose, const hidl_vec<uint8_t>& key,
        const hidl_vec<KeyParameter>& inParams,
        const HardwareAuthToken& authToken,
        begin_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::begin";

    BeginOperationRequest request;
    BeginOperationResponse response;

    request.set_purpose((::nugget::app::keymaster::KeyPurpose)purpose);
    request.mutable_blob()->set_blob(&key[0], key.size());

    hidl_vec<KeyParameter> params;
    if (translate_auth_token(
            authToken, request.mutable_auth_token()) != ErrorCode::OK) {
        _hidl_cb(ErrorCode::INVALID_ARGUMENT, params,
                 response.handle().handle());
        return Void();
    }
    if (hidl_params_to_pb(
            inParams, request.mutable_params()) != ErrorCode::OK) {
      _hidl_cb(ErrorCode::INVALID_ARGUMENT, params,
               response.handle().handle());
      return Void();
    }
    tag_map_t tag_map;
    if (hidl_params_to_map(inParams, &tag_map) != ErrorCode::OK) {
        _hidl_cb(ErrorCode::INVALID_ARGUMENT, params,
                 response.handle().handle());
      return Void();
    }

    KM_CALLV(BeginOperation, request, response, hidl_vec<KeyParameter>{}, 0);

    // Setup HAL buffering for this operation's data.
    Algorithm algorithm;
    if (translate_algorithm(response.algorithm(), &algorithm) !=
        ErrorCode::OK) {
        if (this->abort(response.handle().handle()) != ErrorCode::OK) {
            LOG(ERROR) << "abort( " << response.handle().handle()
                       << ") failed";
        }
        _hidl_cb(ErrorCode::INVALID_ARGUMENT, params,
                 response.handle().handle());
        return Void();
    }
    ErrorCode error_code = buffer_begin(response.handle().handle(), algorithm);
    if (error_code != ErrorCode::OK) {
        if (this->abort(response.handle().handle()) != ErrorCode::OK) {
            LOG(ERROR) << "abort( " << response.handle().handle()
                       << ") failed";
        }
        _hidl_cb(ErrorCode::UNKNOWN_ERROR, params,
                 response.handle().handle());
        return Void();
    }

    pb_to_hidl_params(response.params(), &params);

    _hidl_cb(translate_error_code(response.error_code()), params,
             response.handle().handle());
    return Void();
}

Return<void> KeymasterDevice::update(
        uint64_t operationHandle,
        const hidl_vec<KeyParameter>& inParams,
        const hidl_vec<uint8_t>& input,
        const HardwareAuthToken& authToken,
        const VerificationToken& verificationToken,
        update_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::update";

    UpdateOperationRequest request;
    UpdateOperationResponse response;

    // TODO: does keystore chunk stream data?  To what quantum?
    if (input.size() > KM_MAX_PROTO_FIELD_SIZE) {
        LOG(ERROR) << "Excess input length: " << input.size()
                   << " max allowed: " << KM_MAX_PROTO_FIELD_SIZE;
        if (this->abort(operationHandle) != ErrorCode::OK) {
            LOG(ERROR) << "abort( " << operationHandle
                       << ") failed";
        }
        _hidl_cb(ErrorCode::INVALID_INPUT_LENGTH, 0,
                 hidl_vec<KeyParameter>{}, hidl_vec<uint8_t>{});
        return Void();
    }

    uint32_t consumed;
    hidl_vec<uint8_t> output;
    hidl_vec<KeyParameter> params;
    ErrorCode error_code;
    error_code = buffer_append(operationHandle, input, &consumed);
    if (error_code != ErrorCode::OK) {
        _hidl_cb(error_code, 0, params, output);
        return Void();
    }

    hidl_vec<uint8_t> blocks;
    error_code = buffer_peek(operationHandle, &blocks);
    if (error_code != ErrorCode::OK) {
        _hidl_cb(error_code, 0, params, output);
        return Void();
    }

    // blocks.size() may be zero, but do a round-trip none-the-less
    // since this may be GCM, there may be AAD data in params.
    // TODO: as an optimization, do some inspection apriori.

    request.mutable_handle()->set_handle(operationHandle);

    if (hidl_params_to_pb(
            inParams, request.mutable_params()) != ErrorCode::OK) {
      _hidl_cb(ErrorCode::INVALID_ARGUMENT, 0, params, output);
      return Void();
    }

    request.set_input(&blocks[0], blocks.size());
    if (translate_auth_token(
            authToken, request.mutable_auth_token()) != ErrorCode::OK) {
        _hidl_cb(ErrorCode::INVALID_ARGUMENT, 0, params, output);
        return Void();
    }
    translate_verification_token(verificationToken,
                                 request.mutable_verification_token());

    KM_CALLV(UpdateOperation, request, response,
             0, hidl_vec<KeyParameter>{}, hidl_vec<uint8_t>{});

    if (buffer_advance(operationHandle, response.consumed()) != ErrorCode::OK) {
        _hidl_cb(ErrorCode::UNKNOWN_ERROR, 0, params, output);
        return Void();
    }

    pb_to_hidl_params(response.params(), &params);
    output.setToExternal(
        reinterpret_cast<uint8_t*>(const_cast<char*>(response.output().data())),
        response.output().size(), false);

    _hidl_cb(ErrorCode::OK, consumed, params, output);
    return Void();
}

Return<void> KeymasterDevice::finish(
        uint64_t operationHandle,
        const hidl_vec<KeyParameter>& inParams,
        const hidl_vec<uint8_t>& input,
        const hidl_vec<uint8_t>& signature,
        const HardwareAuthToken& authToken,
        const VerificationToken& verificationToken,
        finish_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::finish";

    FinishOperationRequest request;
    FinishOperationResponse response;

    if (input.size() > KM_MAX_PROTO_FIELD_SIZE) {
        LOG(ERROR) << "Excess input length: " << input.size()
                   << " max allowed: " << KM_MAX_PROTO_FIELD_SIZE;
        if (this->abort(operationHandle) != ErrorCode::OK) {
            LOG(ERROR) << "abort( " << operationHandle
                       << ") failed";
        }
        _hidl_cb(ErrorCode::INVALID_INPUT_LENGTH,
                 hidl_vec<KeyParameter>{}, hidl_vec<uint8_t>{});
        return Void();
    }

    uint32_t consumed;
    ErrorCode error_code;
    error_code = buffer_append(operationHandle, input, &consumed);
    if (error_code != ErrorCode::OK) {
        _hidl_cb(error_code,
                 hidl_vec<KeyParameter>{}, hidl_vec<uint8_t>{});
        return Void();
    }

    hidl_vec<uint8_t> data;
    error_code = buffer_final(operationHandle, &data);
    if (error_code != ErrorCode::OK) {
        _hidl_cb(error_code,
                 hidl_vec<KeyParameter>{}, hidl_vec<uint8_t>{});
        return Void();
    }

    request.mutable_handle()->set_handle(operationHandle);

    hidl_vec<KeyParameter> params;
    hidl_vec<uint8_t> output;
    if (hidl_params_to_pb(
            inParams, request.mutable_params()) != ErrorCode::OK) {
      _hidl_cb(ErrorCode::INVALID_ARGUMENT, params, output);
      return Void();
    }

    request.set_input(&data[0], data.size());
    request.set_signature(&signature[0], signature.size());

    if (translate_auth_token(
            authToken, request.mutable_auth_token()) != ErrorCode::OK) {
        _hidl_cb(ErrorCode::INVALID_ARGUMENT, params, output);
        return Void();
    }
    translate_verification_token(verificationToken,
                                 request.mutable_verification_token());

    KM_CALLV(FinishOperation, request, response,
             hidl_vec<KeyParameter>{}, hidl_vec<uint8_t>{});

    pb_to_hidl_params(response.params(), &params);
    output.setToExternal(
        reinterpret_cast<uint8_t*>(const_cast<char*>(response.output().data())),
        response.output().size(), false);

    _hidl_cb(ErrorCode::OK, params, output);
    return Void();
}

Return<ErrorCode> KeymasterDevice::abort(uint64_t operationHandle)
{
    LOG(VERBOSE) << "Running KeymasterDevice::abort";

    AbortOperationRequest request;
    AbortOperationResponse response;

    request.mutable_handle()->set_handle(operationHandle);

    KM_CALL(AbortOperation, request, response);

    return ErrorCode::OK;
}

// Methods from ::android::hardware::keymaster::V4_0::IKeymasterDevice follow.
Return<void> KeymasterDevice::importWrappedKey(
    const hidl_vec<uint8_t>& wrappedKeyData,
    const hidl_vec<uint8_t>& wrappingKeyBlob,
    const hidl_vec<uint8_t>& maskingKey,
    const hidl_vec<KeyParameter>& /* unwrappingParams */,
    uint64_t /* passwordSid */, uint64_t /* biometricSid */,
    importWrappedKey_cb _hidl_cb)
{
    LOG(VERBOSE) << "Running KeymasterDevice::importWrappedKey";

    ErrorCode error;
    ImportWrappedKeyRequest request;
    ImportKeyResponse response;

    if (maskingKey.size() != KM_WRAPPER_MASKING_KEY_SIZE) {
        _hidl_cb(ErrorCode::INVALID_ARGUMENT, hidl_vec<uint8_t>{},
                 KeyCharacteristics{});
        return Void();
    }

    error = import_wrapped_key_request(wrappedKeyData, wrappingKeyBlob,
                                       maskingKey, &request);
    if (error != ErrorCode::OK) {
        LOG(ERROR) << "ImportWrappedKey request parsing failed with error "
                   << error;
        _hidl_cb(error, hidl_vec<uint8_t>{}, KeyCharacteristics{});
        return Void();
    }

    KM_CALLV(ImportWrappedKey, request, response,
             hidl_vec<uint8_t>{}, KeyCharacteristics{});

    hidl_vec<uint8_t> blob;
    blob.setToExternal(
        reinterpret_cast<uint8_t*>(
            const_cast<char*>(response.blob().blob().data())),
        response.blob().blob().size(), false);

    KeyCharacteristics characteristics;
    // TODO: anything to do here with softwareEnforced?
    pb_to_hidl_params(response.characteristics().software_enforced(),
                      &characteristics.softwareEnforced);
    error = pb_to_hidl_params(response.characteristics().tee_enforced(),
                              &characteristics.hardwareEnforced);
    if (error != ErrorCode::OK) {
        LOG(ERROR) <<
            "KeymasterDevice::importWrappedKey: response tee_enforced :"
                   << error;
        _hidl_cb(error, hidl_vec<uint8_t>{}, KeyCharacteristics{});
        return Void();
    }

    _hidl_cb(ErrorCode::OK, blob, characteristics);
    return Void();
}

// Private methods.
Return<ErrorCode> KeymasterDevice::SendSystemVersionInfo() const {
    SetSystemVersionInfoRequest request;
    SetSystemVersionInfoResponse response;

    request.set_system_version(_os_version);
    request.set_system_security_level(_os_patchlevel);
    request.set_vendor_security_level(_vendor_patchlevel);

    KM_CALL(SetSystemVersionInfo, request, response);
    return ErrorCode::OK;
}

Return<ErrorCode> KeymasterDevice::GetBootInfo() {
    GetBootInfoRequest request;
    GetBootInfoResponse response;

    KM_CALL(GetBootInfo, request, response);

    _is_unlocked = response.is_unlocked();
    _boot_color = response.boot_color();
    _boot_key.assign(response.boot_key().begin(), response.boot_key().end());
    _boot_hash.assign(response.boot_hash().begin(), response.boot_hash().end());
    return ErrorCode::OK;
}

}  // namespace keymaster
}  // namespace hardware
}  // namespace android