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/*
*
* Copyright (c) 2021-2022 Project CHIP Authors
* All rights reserved.
*
* 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.
*/
/**
* @file
* Platform-specific key value storage implementation for ESP32
*/
#include <platform/ESP32/ScopedNvsHandle.h>
#include <platform/KeyValueStoreManager.h>
#include <string.h>
#include "nvs.h"
#include "nvs_flash.h"
#include <crypto/CHIPCryptoPAL.h>
#include <lib/core/CHIPSafeCasts.h>
#include <lib/support/BytesToHex.h>
#include <lib/support/CodeUtils.h>
namespace chip {
namespace DeviceLayer {
namespace PersistedStorage {
namespace {
// Implementation Note: esp-idf nvs implementation cannot handle key length > 15,
// Below implementation tries to handle that case by hashing the key
// If key length is > 15 then take the SHA1 of the key and convert the first 7.5 bytes to hex string.
// Not sure how likely we would run into a conflict as we are only using 8 bytes out of 20
//
// key returned by below function will not collide with any existing "normal" keys because those always have a "/" in
// the first few chars and the output of this code never will.
//
// Returns true if key is hashed, false otherwise.
bool HashIfLongKey(const char * key, char * keyHash)
{
ReturnErrorCodeIf(strlen(key) < NVS_KEY_NAME_MAX_SIZE, false);
uint8_t hashBuffer[chip::Crypto::kSHA1_Hash_Length];
ReturnErrorCodeIf(Crypto::Hash_SHA1(Uint8::from_const_char(key), strlen(key), hashBuffer) != CHIP_NO_ERROR, false);
BitFlags<Encoding::HexFlags> flags(Encoding::HexFlags::kNone);
Encoding::BytesToHex(hashBuffer, NVS_KEY_NAME_MAX_SIZE / 2, keyHash, NVS_KEY_NAME_MAX_SIZE, flags);
keyHash[NVS_KEY_NAME_MAX_SIZE - 1] = 0;
ChipLogDetail(DeviceLayer, "Using hash:%s for nvs key:%s", keyHash, StringOrNullMarker(key));
return true;
}
} // namespace
KeyValueStoreManagerImpl KeyValueStoreManagerImpl::sInstance;
CHIP_ERROR KeyValueStoreManagerImpl::_Get(const char * key, void * value, size_t value_size, size_t * read_bytes_size,
size_t offset_bytes)
{
VerifyOrReturnError(value, CHIP_ERROR_INVALID_ARGUMENT);
// Offset and partial reads are not supported in nvs, for now just return NOT_IMPLEMENTED. Support can be added in the
// future if this is needed.
VerifyOrReturnError(offset_bytes == 0, CHIP_ERROR_NOT_IMPLEMENTED);
Internal::ScopedNvsHandle handle;
ReturnErrorOnFailure(handle.Open(kNamespace, NVS_READONLY, CHIP_DEVICE_CONFIG_CHIP_KVS_NAMESPACE_PARTITION));
char keyHash[NVS_KEY_NAME_MAX_SIZE];
VerifyOrDo(HashIfLongKey(key, keyHash) == false, key = keyHash);
ReturnMappedErrorOnFailure(nvs_get_blob(handle, key, value, &value_size));
if (read_bytes_size)
{
*read_bytes_size = value_size;
}
return CHIP_NO_ERROR;
}
CHIP_ERROR KeyValueStoreManagerImpl::_Put(const char * key, const void * value, size_t value_size)
{
VerifyOrReturnError(value, CHIP_ERROR_INVALID_ARGUMENT);
Internal::ScopedNvsHandle handle;
ReturnErrorOnFailure(handle.Open(kNamespace, NVS_READWRITE, CHIP_DEVICE_CONFIG_CHIP_KVS_NAMESPACE_PARTITION));
char keyHash[NVS_KEY_NAME_MAX_SIZE];
VerifyOrDo(HashIfLongKey(key, keyHash) == false, key = keyHash);
ReturnMappedErrorOnFailure(nvs_set_blob(handle, key, value, value_size));
// Commit the value to the persistent store.
ReturnMappedErrorOnFailure(nvs_commit(handle));
return CHIP_NO_ERROR;
}
CHIP_ERROR KeyValueStoreManagerImpl::_Delete(const char * key)
{
Internal::ScopedNvsHandle handle;
ReturnErrorOnFailure(handle.Open(kNamespace, NVS_READWRITE, CHIP_DEVICE_CONFIG_CHIP_KVS_NAMESPACE_PARTITION));
char keyHash[NVS_KEY_NAME_MAX_SIZE];
VerifyOrDo(HashIfLongKey(key, keyHash) == false, key = keyHash);
ReturnMappedErrorOnFailure(nvs_erase_key(handle, key));
// Commit the value to the persistent store.
ReturnMappedErrorOnFailure(nvs_commit(handle));
return CHIP_NO_ERROR;
}
CHIP_ERROR KeyValueStoreManagerImpl::EraseAll(void)
{
Internal::ScopedNvsHandle handle;
ReturnErrorOnFailure(handle.Open(kNamespace, NVS_READWRITE, CHIP_DEVICE_CONFIG_CHIP_KVS_NAMESPACE_PARTITION));
ReturnMappedErrorOnFailure(nvs_erase_all(handle));
ReturnMappedErrorOnFailure(nvs_commit(handle));
return CHIP_NO_ERROR;
}
} // namespace PersistedStorage
} // namespace DeviceLayer
} // namespace chip