src/platform/nRF5/GroupKeyStoreImpl.cpp - third_party/github/project-chip/connectedhomeip - Git at Google

 /*
  *
  *    Copyright (c) 2020 Project CHIP Authors
  *    Copyright (c) 2018 Nest Labs, Inc.
  *
  *    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
  *          Provides an implementation of the CHIP GroupKeyStore interface
  *          for platforms based on the Nordic nRF5 SDK.
  */

 #include <platform/internal/CHIPDeviceLayerInternal.h>
 #include <platform/nRF5/GroupKeyStoreImpl.h>

 #include "mem_manager.h"

 using namespace ::chip;
 using namespace ::chip::Profiles::Security::AppKeys;

 namespace chip {
 namespace DeviceLayer {
 namespace Internal {

 CHIP_ERROR GroupKeyStoreImpl::RetrieveGroupKey(uint32_t keyId, ChipGroupKey & key)
 {
     CHIP_ERROR err;

     // Iterate over all the GroupKey records looking for a matching key...
     err = ForEachRecord(kGroupKeyFileId, kGroupKeyRecordKey,
               [keyId, &key](const fds_flash_record_t & rec, bool & deleteRec) -> CHIP_ERROR
               {
                   uint32_t curKeyId;
                   CHIP_ERROR err2 = CHIP_NO_ERROR;

                   // Decode the CHIP key id for the current key.
                   err2 = DecodeGroupKeyId((const uint8_t *)rec.p_data, rec.p_header->length_words * kFDSWordSize, curKeyId);
                   SuccessOrExit(err2);

                   // If it matches the key we're looking for...
                   if (curKeyId == keyId)
                   {
                       // Decode the associated key data.
                       err2 = DecodeGroupKey((const uint8_t *)rec.p_data, rec.p_header->length_words * kFDSWordSize, key);
                       SuccessOrExit(err2);

                       // End the iteration by returning a CHIP_END_OF_INPUT result.
                       ExitNow(err2 = CHIP_END_OF_INPUT);
                   }

               exit:
                   return err2;
               }
           );

     // If a matching key was found, return success.
     if (err == CHIP_END_OF_INPUT)
     {
         err = CHIP_NO_ERROR;
     }

     // If no match was found, return CHIP_ERROR_KEY_NOT_FOUND.
     else if (err == CHIP_NO_ERROR)
     {
         err = CHIP_ERROR_KEY_NOT_FOUND;
     }
     SuccessOrExit(err);

 exit:
     return err;
 }

 CHIP_ERROR GroupKeyStoreImpl::StoreGroupKey(const ChipGroupKey & key)
 {
     CHIP_ERROR err;
     uint8_t * storedVal = NULL;
     size_t storedValLen = FDSWords(kMaxEncodedKeySize) * kFDSWordSize;

     // Delete any existing group key with the same id.
     err = DeleteGroupKey(key.KeyId);
     SuccessOrExit(err);

     // Allocate a buffer to hold the encoded key.
     storedVal = (uint8_t *)nrf_malloc(storedValLen);
     VerifyOrExit(storedVal != NULL, err = CHIP_ERROR_NO_MEMORY);

     // Encode the key for storage in an FDS record.
     err = EncodeGroupKey(key, storedVal, storedValLen, storedValLen);
     SuccessOrExit(err);

     // Add a GroupKey FDS record containing the encoded key.
     {
         FDSAsyncOp addOp(FDSAsyncOp::kAddRecord);
         addOp.FileId = kGroupKeyFileId;
         addOp.RecordKey = kGroupKeyRecordKey;
         addOp.RecordData = storedVal;
         addOp.RecordDataLengthWords = FDSWords(storedValLen);
         err = DoAsyncFDSOp(addOp);
         SuccessOrExit(err);
     }

 #if CHIP_PROGRESS_LOGGING

     {
         char extraKeyInfo[32];
         if (ChipKeyId::IsAppEpochKey(key.KeyId))
         {
             snprintf(extraKeyInfo, sizeof(extraKeyInfo), ", start time %" PRId32, key.StartTime);
         }
         else if (ChipKeyId::IsAppGroupMasterKey(key.KeyId))
         {
             snprintf(extraKeyInfo, sizeof(extraKeyInfo), ", global id 0x%08" PRIX32, key.GlobalId);
         }
         else
         {
             extraKeyInfo[0] = 0;
         }

 #if CHIP_CONFIG_SECURITY_TEST_MODE
         ChipLogProgress(SecurityManager, "GroupKeyStore: storing key 0x%08" PRIX32 " (%s), len %" PRId8 ", data 0x%02" PRIX8 "...%s",
                 key.KeyId, ChipKeyId::DescribeKey(key.KeyId), key.KeyLen, key.Key[0], extraKeyInfo);
 #else
         ChipLogProgress(SecurityManager, "GroupKeyStore: storing key 0x%08" PRIX32 " (%s), len %" PRId8 "%s",
                 key.KeyId, ChipKeyId::DescribeKey(key.KeyId), key.KeyLen, extraKeyInfo);
 #endif
     }

 #endif // CHIP_PROGRESS_LOGGING

 exit:
     if (storedVal != NULL)
     {
         ClearSecretData(storedVal, storedValLen);
         nrf_free(storedVal);
     }
     return err;
 }

 CHIP_ERROR GroupKeyStoreImpl::DeleteGroupKey(uint32_t keyId)
 {
     CHIP_ERROR err;

     // Iterate over all the GroupKey records looking for matching keys...
     err = ForEachRecord(kGroupKeyFileId, kGroupKeyRecordKey,
               [keyId](const fds_flash_record_t & rec, bool & deleteRec) -> CHIP_ERROR
               {
                   uint32_t curKeyId;
                   CHIP_ERROR err2;

                   // Decode the CHIP key id for the current group key.
                   err2 = DecodeGroupKeyId((const uint8_t *)rec.p_data, rec.p_header->length_words * kFDSWordSize, curKeyId);
                   SuccessOrExit(err2);

                   // If it matches the key looking for, arrange for the record to be deleted.
                   deleteRec = (curKeyId == keyId);

                   if (deleteRec)
                   {
                       ChipLogProgress(DeviceLayer, "GroupKeyStore: deleting key 0x%08" PRIX32, curKeyId);
                   }

               exit:
                   return err2;
               }
           );
     SuccessOrExit(err);

 exit:
     return err;
 }

 CHIP_ERROR GroupKeyStoreImpl::DeleteGroupKeysOfAType(uint32_t keyType)
 {
     CHIP_ERROR err;

     // Iterate over all the GroupKey records looking for matching keys...
     err = ForEachRecord(kGroupKeyFileId, kGroupKeyRecordKey,
               [keyType](const fds_flash_record_t & rec, bool & deleteRec) -> CHIP_ERROR
               {
                   uint32_t curKeyId;
                   CHIP_ERROR err2;

                   // Decode the CHIP key id for the current group key.
                   err2 = DecodeGroupKeyId((const uint8_t *)rec.p_data, rec.p_header->length_words * kFDSWordSize, curKeyId);
                   SuccessOrExit(err2);

                   // If the current key matches the type we're looking for, arrange for the
                   // record to be deleted.
                   deleteRec = (ChipKeyId::GetType(curKeyId) == keyType);

                   if (deleteRec)
                   {
                       ChipLogProgress(DeviceLayer, "GroupKeyStore: deleting key 0x%08" PRIX32, curKeyId);
                   }

               exit:
                   return err2;
               }
           );
     SuccessOrExit(err);

 exit:
     return err;
 }

 CHIP_ERROR GroupKeyStoreImpl::EnumerateGroupKeys(uint32_t keyType, uint32_t * keyIds,
         uint8_t keyIdsArraySize, uint8_t & keyCount)
 {
     CHIP_ERROR err;

     keyCount = 0;

     // Iterate over all the GroupKey records looking for keys of the specified type...
     err = ForEachRecord(kGroupKeyFileId, kGroupKeyRecordKey,
               [keyType, keyIds, keyIdsArraySize, &keyCount](const fds_flash_record_t & rec, bool & deleteRec) -> CHIP_ERROR
               {
                   uint32_t curKeyId;
                   CHIP_ERROR err2 = CHIP_NO_ERROR;

                   // Decode the CHIP key id for the current key.
                   err2 = DecodeGroupKeyId((const uint8_t *)rec.p_data, rec.p_header->length_words * kFDSWordSize, curKeyId);
                   SuccessOrExit(err2);

                   // If the current key matches the type we're looking for, add it to the keyIds array.
                   if (keyType == ChipKeyId::kType_None || ChipKeyId::GetType(curKeyId) == keyType)
                   {
                       keyIds[keyCount++] = curKeyId;

                       // Stop iterating if there's no more room in the keyIds array.
                       VerifyOrExit(keyCount < keyIdsArraySize, err2 = CHIP_ERROR_BUFFER_TOO_SMALL);
                   }

               exit:
                   return err2;
               }
           );

     // Simply return a truncated list if there are more matching keys than will fit in the array.
     if (err == CHIP_ERROR_BUFFER_TOO_SMALL)
     {
         err = CHIP_NO_ERROR;
     }
     SuccessOrExit(err);

 exit:
     return err;
 }

 CHIP_ERROR GroupKeyStoreImpl::Clear(void)
 {
     CHIP_ERROR err;

     // Iterate over all GroupKey records deleting each one.
     err = ForEachRecord(kGroupKeyFileId, kGroupKeyRecordKey,
               [](const fds_flash_record_t & rec, bool & deleteRec) -> CHIP_ERROR
               {
                   deleteRec = true;
                   return CHIP_NO_ERROR;
               }
           );
     SuccessOrExit(err);

     ChipLogProgress(DeviceLayer, "GroupKeyStore: cleared");

 exit:
     return err;
 }

 CHIP_ERROR GroupKeyStoreImpl::RetrieveLastUsedEpochKeyId(void)
 {
     CHIP_ERROR err;

     err = ReadConfigValue(kConfigKey_LastUsedEpochKeyId, LastUsedEpochKeyId);
     if (err == CHIP_DEVICE_ERROR_CONFIG_NOT_FOUND)
     {
         LastUsedEpochKeyId = ChipKeyId::kNone;
         err = CHIP_NO_ERROR;
     }
     return err;
 }

 CHIP_ERROR GroupKeyStoreImpl::StoreLastUsedEpochKeyId(void)
 {
     return WriteConfigValue(kConfigKey_LastUsedEpochKeyId, LastUsedEpochKeyId);
 }

 CHIP_ERROR GroupKeyStoreImpl::Init()
 {
     // Nothing to do
     return CHIP_NO_ERROR;
 }

 CHIP_ERROR GroupKeyStoreImpl::EncodeGroupKey(const ChipGroupKey & key, uint8_t * buf, size_t bufSize, size_t & encodedKeyLen)
 {
     CHIP_ERROR err = CHIP_NO_ERROR;
     uint8_t * p = buf;

     VerifyOrExit(bufSize >= kFixedEncodedKeySize + key.KeyLen, err = CHIP_ERROR_BUFFER_TOO_SMALL);

     Encoding::LittleEndian::Write32(p, key.KeyId);
     Encoding::LittleEndian::Write32(p, key.StartTime);
     Encoding::Write8(p, key.KeyLen);
     memcpy(p, key.Key, key.KeyLen);
     p += key.KeyLen;

     encodedKeyLen = p - buf;

 exit:
     return err;
 }

 CHIP_ERROR GroupKeyStoreImpl::DecodeGroupKey(const uint8_t * encodedKey, size_t encodedKeyLen, ChipGroupKey & key)
 {
     CHIP_ERROR err = CHIP_NO_ERROR;
     const uint8_t * p = encodedKey;

     VerifyOrExit(encodedKeyLen >= kFixedEncodedKeySize, err = CHIP_ERROR_INVALID_ARGUMENT);

     key.KeyId = Encoding::LittleEndian::Read32(p);
     key.StartTime = Encoding::LittleEndian::Read32(p);
     key.KeyLen = Encoding::Read8(p);

     VerifyOrExit(encodedKeyLen >= kFixedEncodedKeySize + key.KeyLen, err = CHIP_ERROR_INVALID_ARGUMENT);

     memcpy(key.Key, p, key.KeyLen);

 exit:
     return err;
 }

 CHIP_ERROR GroupKeyStoreImpl::DecodeGroupKeyId(const uint8_t * encodedKey, size_t encodedKeyLen, uint32_t & keyId)
 {
     CHIP_ERROR err = CHIP_NO_ERROR;

     VerifyOrExit(encodedKeyLen >= kFixedEncodedKeySize, err = CHIP_ERROR_INVALID_ARGUMENT);

     keyId = Encoding::LittleEndian::Get32(encodedKey);

 exit:
     return err;
 }

 } // namespace Internal
 } // namespace DeviceLayer
 } // namespace chip
	/*
	*
	* Copyright (c) 2020 Project CHIP Authors
	* Copyright (c) 2018 Nest Labs, Inc.
	*
	* 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
	* Provides an implementation of the CHIP GroupKeyStore interface
	* for platforms based on the Nordic nRF5 SDK.
	*/

	#include <platform/internal/CHIPDeviceLayerInternal.h>
	#include <platform/nRF5/GroupKeyStoreImpl.h>

	#include "mem_manager.h"

	using namespace ::chip;
	using namespace ::chip::Profiles::Security::AppKeys;

	namespace chip {
	namespace DeviceLayer {
	namespace Internal {

	CHIP_ERROR GroupKeyStoreImpl::RetrieveGroupKey(uint32_t keyId, ChipGroupKey & key)
	{
	CHIP_ERROR err;

	// Iterate over all the GroupKey records looking for a matching key...
	err = ForEachRecord(kGroupKeyFileId, kGroupKeyRecordKey,
	[keyId, &key](const fds_flash_record_t & rec, bool & deleteRec) -> CHIP_ERROR
	{
	uint32_t curKeyId;
	CHIP_ERROR err2 = CHIP_NO_ERROR;

	// Decode the CHIP key id for the current key.
	err2 = DecodeGroupKeyId((const uint8_t )rec.p_data, rec.p_header->length_words kFDSWordSize, curKeyId);
	SuccessOrExit(err2);

	// If it matches the key we're looking for...
	if (curKeyId == keyId)
	{
	// Decode the associated key data.
	err2 = DecodeGroupKey((const uint8_t )rec.p_data, rec.p_header->length_words kFDSWordSize, key);
	SuccessOrExit(err2);

	// End the iteration by returning a CHIP_END_OF_INPUT result.
	ExitNow(err2 = CHIP_END_OF_INPUT);
	}

	exit:
	return err2;
	}
	);

	// If a matching key was found, return success.
	if (err == CHIP_END_OF_INPUT)
	{
	err = CHIP_NO_ERROR;
	}

	// If no match was found, return CHIP_ERROR_KEY_NOT_FOUND.
	else if (err == CHIP_NO_ERROR)
	{
	err = CHIP_ERROR_KEY_NOT_FOUND;
	}
	SuccessOrExit(err);

	exit:
	return err;
	}

	CHIP_ERROR GroupKeyStoreImpl::StoreGroupKey(const ChipGroupKey & key)
	{
	CHIP_ERROR err;
	uint8_t * storedVal = NULL;
	size_t storedValLen = FDSWords(kMaxEncodedKeySize) * kFDSWordSize;

	// Delete any existing group key with the same id.
	err = DeleteGroupKey(key.KeyId);
	SuccessOrExit(err);

	// Allocate a buffer to hold the encoded key.
	storedVal = (uint8_t *)nrf_malloc(storedValLen);
	VerifyOrExit(storedVal != NULL, err = CHIP_ERROR_NO_MEMORY);

	// Encode the key for storage in an FDS record.
	err = EncodeGroupKey(key, storedVal, storedValLen, storedValLen);
	SuccessOrExit(err);

	// Add a GroupKey FDS record containing the encoded key.
	{
	FDSAsyncOp addOp(FDSAsyncOp::kAddRecord);
	addOp.FileId = kGroupKeyFileId;
	addOp.RecordKey = kGroupKeyRecordKey;
	addOp.RecordData = storedVal;
	addOp.RecordDataLengthWords = FDSWords(storedValLen);
	err = DoAsyncFDSOp(addOp);
	SuccessOrExit(err);
	}

	#if CHIP_PROGRESS_LOGGING

	{
	char extraKeyInfo[32];
	if (ChipKeyId::IsAppEpochKey(key.KeyId))
	{
	snprintf(extraKeyInfo, sizeof(extraKeyInfo), ", start time %" PRId32, key.StartTime);
	}
	else if (ChipKeyId::IsAppGroupMasterKey(key.KeyId))
	{
	snprintf(extraKeyInfo, sizeof(extraKeyInfo), ", global id 0x%08" PRIX32, key.GlobalId);
	}
	else
	{
	extraKeyInfo[0] = 0;
	}

	#if CHIP_CONFIG_SECURITY_TEST_MODE
	ChipLogProgress(SecurityManager, "GroupKeyStore: storing key 0x%08" PRIX32 " (%s), len %" PRId8 ", data 0x%02" PRIX8 "...%s",
	key.KeyId, ChipKeyId::DescribeKey(key.KeyId), key.KeyLen, key.Key[0], extraKeyInfo);
	#else
	ChipLogProgress(SecurityManager, "GroupKeyStore: storing key 0x%08" PRIX32 " (%s), len %" PRId8 "%s",
	key.KeyId, ChipKeyId::DescribeKey(key.KeyId), key.KeyLen, extraKeyInfo);
	#endif
	}

	#endif // CHIP_PROGRESS_LOGGING

	exit:
	if (storedVal != NULL)
	{
	ClearSecretData(storedVal, storedValLen);
	nrf_free(storedVal);
	}
	return err;
	}

	CHIP_ERROR GroupKeyStoreImpl::DeleteGroupKey(uint32_t keyId)
	{
	CHIP_ERROR err;

	// Iterate over all the GroupKey records looking for matching keys...
	err = ForEachRecord(kGroupKeyFileId, kGroupKeyRecordKey,
	[keyId](const fds_flash_record_t & rec, bool & deleteRec) -> CHIP_ERROR
	{
	uint32_t curKeyId;
	CHIP_ERROR err2;

	// Decode the CHIP key id for the current group key.
	err2 = DecodeGroupKeyId((const uint8_t )rec.p_data, rec.p_header->length_words kFDSWordSize, curKeyId);
	SuccessOrExit(err2);

	// If it matches the key looking for, arrange for the record to be deleted.
	deleteRec = (curKeyId == keyId);

	if (deleteRec)
	{
	ChipLogProgress(DeviceLayer, "GroupKeyStore: deleting key 0x%08" PRIX32, curKeyId);
	}

	exit:
	return err2;
	}
	);
	SuccessOrExit(err);

	exit:
	return err;
	}

	CHIP_ERROR GroupKeyStoreImpl::DeleteGroupKeysOfAType(uint32_t keyType)
	{
	CHIP_ERROR err;

	// Iterate over all the GroupKey records looking for matching keys...
	err = ForEachRecord(kGroupKeyFileId, kGroupKeyRecordKey,
	[keyType](const fds_flash_record_t & rec, bool & deleteRec) -> CHIP_ERROR
	{
	uint32_t curKeyId;
	CHIP_ERROR err2;

	// Decode the CHIP key id for the current group key.
	err2 = DecodeGroupKeyId((const uint8_t )rec.p_data, rec.p_header->length_words kFDSWordSize, curKeyId);
	SuccessOrExit(err2);

	// If the current key matches the type we're looking for, arrange for the
	// record to be deleted.
	deleteRec = (ChipKeyId::GetType(curKeyId) == keyType);

	if (deleteRec)
	{
	ChipLogProgress(DeviceLayer, "GroupKeyStore: deleting key 0x%08" PRIX32, curKeyId);
	}

	exit:
	return err2;
	}
	);
	SuccessOrExit(err);

	exit:
	return err;
	}

	CHIP_ERROR GroupKeyStoreImpl::EnumerateGroupKeys(uint32_t keyType, uint32_t * keyIds,
	uint8_t keyIdsArraySize, uint8_t & keyCount)
	{
	CHIP_ERROR err;

	keyCount = 0;

	// Iterate over all the GroupKey records looking for keys of the specified type...
	err = ForEachRecord(kGroupKeyFileId, kGroupKeyRecordKey,
	[keyType, keyIds, keyIdsArraySize, &keyCount](const fds_flash_record_t & rec, bool & deleteRec) -> CHIP_ERROR
	{
	uint32_t curKeyId;
	CHIP_ERROR err2 = CHIP_NO_ERROR;

	// Decode the CHIP key id for the current key.
	err2 = DecodeGroupKeyId((const uint8_t )rec.p_data, rec.p_header->length_words kFDSWordSize, curKeyId);
	SuccessOrExit(err2);

	// If the current key matches the type we're looking for, add it to the keyIds array.
	if (keyType == ChipKeyId::kType_None \|\| ChipKeyId::GetType(curKeyId) == keyType)
	{
	keyIds[keyCount++] = curKeyId;

	// Stop iterating if there's no more room in the keyIds array.
	VerifyOrExit(keyCount < keyIdsArraySize, err2 = CHIP_ERROR_BUFFER_TOO_SMALL);
	}

	exit:
	return err2;
	}
	);

	// Simply return a truncated list if there are more matching keys than will fit in the array.
	if (err == CHIP_ERROR_BUFFER_TOO_SMALL)
	{
	err = CHIP_NO_ERROR;
	}
	SuccessOrExit(err);

	exit:
	return err;
	}

	CHIP_ERROR GroupKeyStoreImpl::Clear(void)
	{
	CHIP_ERROR err;

	// Iterate over all GroupKey records deleting each one.
	err = ForEachRecord(kGroupKeyFileId, kGroupKeyRecordKey,
	[](const fds_flash_record_t & rec, bool & deleteRec) -> CHIP_ERROR
	{
	deleteRec = true;
	return CHIP_NO_ERROR;
	}
	);
	SuccessOrExit(err);

	ChipLogProgress(DeviceLayer, "GroupKeyStore: cleared");

	exit:
	return err;
	}

	CHIP_ERROR GroupKeyStoreImpl::RetrieveLastUsedEpochKeyId(void)
	{
	CHIP_ERROR err;

	err = ReadConfigValue(kConfigKey_LastUsedEpochKeyId, LastUsedEpochKeyId);
	if (err == CHIP_DEVICE_ERROR_CONFIG_NOT_FOUND)
	{
	LastUsedEpochKeyId = ChipKeyId::kNone;
	err = CHIP_NO_ERROR;
	}
	return err;
	}

	CHIP_ERROR GroupKeyStoreImpl::StoreLastUsedEpochKeyId(void)
	{
	return WriteConfigValue(kConfigKey_LastUsedEpochKeyId, LastUsedEpochKeyId);
	}

	CHIP_ERROR GroupKeyStoreImpl::Init()
	{
	// Nothing to do
	return CHIP_NO_ERROR;
	}

	CHIP_ERROR GroupKeyStoreImpl::EncodeGroupKey(const ChipGroupKey & key, uint8_t * buf, size_t bufSize, size_t & encodedKeyLen)
	{
	CHIP_ERROR err = CHIP_NO_ERROR;
	uint8_t * p = buf;

	VerifyOrExit(bufSize >= kFixedEncodedKeySize + key.KeyLen, err = CHIP_ERROR_BUFFER_TOO_SMALL);

	Encoding::LittleEndian::Write32(p, key.KeyId);
	Encoding::LittleEndian::Write32(p, key.StartTime);
	Encoding::Write8(p, key.KeyLen);
	memcpy(p, key.Key, key.KeyLen);
	p += key.KeyLen;

	encodedKeyLen = p - buf;

	exit:
	return err;
	}

	CHIP_ERROR GroupKeyStoreImpl::DecodeGroupKey(const uint8_t * encodedKey, size_t encodedKeyLen, ChipGroupKey & key)
	{
	CHIP_ERROR err = CHIP_NO_ERROR;
	const uint8_t * p = encodedKey;

	VerifyOrExit(encodedKeyLen >= kFixedEncodedKeySize, err = CHIP_ERROR_INVALID_ARGUMENT);

	key.KeyId = Encoding::LittleEndian::Read32(p);
	key.StartTime = Encoding::LittleEndian::Read32(p);
	key.KeyLen = Encoding::Read8(p);

	VerifyOrExit(encodedKeyLen >= kFixedEncodedKeySize + key.KeyLen, err = CHIP_ERROR_INVALID_ARGUMENT);

	memcpy(key.Key, p, key.KeyLen);

	exit:
	return err;
	}

	CHIP_ERROR GroupKeyStoreImpl::DecodeGroupKeyId(const uint8_t * encodedKey, size_t encodedKeyLen, uint32_t & keyId)
	{
	CHIP_ERROR err = CHIP_NO_ERROR;

	VerifyOrExit(encodedKeyLen >= kFixedEncodedKeySize, err = CHIP_ERROR_INVALID_ARGUMENT);

	keyId = Encoding::LittleEndian::Get32(encodedKey);

	exit:
	return err;
	}

	} // namespace Internal
	} // namespace DeviceLayer
	} // namespace chip