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TencentOS-tiny/components/connectivity/LoraWAN/mac/LoRaMacCrypto.c
supowang edb2879617 first commit for opensource 
first commit for opensource
2019-09-16 13:19:50 +08:00

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/*!
* \file LoRaMacCrypto.c
*
* \brief LoRa MAC layer cryptography implementation
*
* \copyright Revised BSD License, see section \ref LICENSE.
*
* \code
* ______ _
* / _____) _ | |
* ( (____ _____ ____ _| |_ _____ ____| |__
* \____ \| ___ | (_ _) ___ |/ ___) _ \
* _____) ) ____| | | || |_| ____( (___| | | |
* (______/|_____)_|_|_| \__)_____)\____)_| |_|
* (C)2013-2017 Semtech
*
* ___ _____ _ ___ _ _____ ___ ___ ___ ___
* / __|_ _/_\ / __| |/ / __/ _ \| _ \/ __| __|
* \__ \ | |/ _ \ (__| ' <| _| (_) | / (__| _|
* |___/ |_/_/ \_\___|_|\_\_| \___/|_|_\\___|___|
* embedded.connectivity.solutions===============
*
* \endcode
*
* \author Miguel Luis ( Semtech )
*
* \author Gregory Cristian ( Semtech )
*
* \author Daniel Jaeckle ( STACKFORCE )
*
* \author Johannes Bruder ( STACKFORCE )
*/
#include <stdbool.h>
#include <stdlib.h>
#include <stdint.h>
#include "utilities.h"
#include "secure-element.h"
#include "LoRaMacParser.h"
#include "LoRaMacSerializer.h"
#include "LoRaMacCrypto.h"
/*
* Initial value of the frame counters
*/
#define FCNT_DOWN_INITAL_VALUE 0xFFFFFFFF
/*
* Frame direction definition for uplink communications
*/
#define UPLINK 0
/*
* Frame direction definition for downlink communications
*/
#define DOWNLINK 1
/*
* CMAC/AES Message Integrity Code (MIC) Block B0 size
*/
#define MIC_BLOCK_BX_SIZE 16
/*
* Size of JoinReqType is field for integrity check
*/
#define JOIN_REQ_TYPE_SIZE 1
/*
* Size of DevNonce is field for integrity check
*/
#define DEV_NONCE_SIZE 2
/*
* Number of security context entries
*/
#define NUM_OF_SEC_CTX 5
/*
* Size of the module context
*/
#define CRYPTO_CTX_SIZE sizeof( LoRaMacCryptoCtx_t )
/*
* Size of the module non volatile context
*/
#define CRYPTO_NVM_CTX_SIZE sizeof( LoRaMacCryptoNvmCtx_t )
/*
* Maximum size of the message that can be handled by the crypto operations
*/
#define CRYPTO_MAXMESSAGE_SIZE 256
/*
* Maximum size of the buffer for crypto operations
*/
#define CRYPTO_BUFFER_SIZE CRYPTO_MAXMESSAGE_SIZE + MIC_BLOCK_BX_SIZE
/*
* MIC computaion offset
*/
#define CRYPTO_MIC_COMPUTATION_OFFSET JOIN_REQ_TYPE_SIZE + LORAMAC_JOIN_EUI_FIELD_SIZE + DEV_NONCE_SIZE + LORAMAC_MHDR_FIELD_SIZE
/*
* LoRaMac Crypto Non Volatile Context structure
*/
typedef struct sLoRaMacCryptoNvmCtx
{
/*
* Device nonce is a counter starting at 0 when the device is initially
* powered up and incremented with every JoinRequest.
*/
uint16_t DevNonce;
/*
* JoinNonce is a device specific counter value (that never repeats itself)
* provided by the join server and incremented with every JoinAccept message.
*/
uint32_t JoinNonce;
/*
* Uplink frame counter.
*/
uint32_t FCntUp;
/*
* Network downlink frame counter.
*/
uint32_t NFCntDown;
/*
* Application downlink frame counter.
*/
uint32_t AFCntDown;
/*
* Downlink frame counter for LoRaWAN 1.0 Server
*/
uint32_t FCntDown;
/*!
* Multicast downlink counter for index 0
*/
uint32_t McFCntDown0;
/*!
* Multicast downlink counter for index 1
*/
uint32_t McFCntDown1;
/*!
* Multicast downlink counter for index 2
*/
uint32_t McFCntDown2;
/*!
* Multicast downlink counter for index 3
*/
uint32_t McFCntDown3;
/*
* RJcount1 is a counter incremented with every Rejoin request Type 1 frame transmitted.
*/
uint16_t RJcount1;
/*
* LastDownFCnt stores the information which frame counter was used to unsecure the last frame.
* This information is needed to compute ConfFCnt in B1 block for the MIC.
*/
uint32_t* LastDownFCnt;
}LoRaMacCryptoNvmCtx_t;
/*
* LoRaMac Crypto Context structure
*/
typedef struct sLoRaMacCryptoCtx
{
/*
* Stores the information if the device is connected to a LoRaWAN network
* server with prior to 1.1.0 implementation.
*/
Version_t LrWanVersion;
/*
* RJcount0 is a counter incremented with every Type 0 or 2 Rejoin frame transmitted.
*/
uint16_t RJcount0;
/*
* Non volatile module context structure
*/
LoRaMacCryptoNvmCtx_t* NvmCtx;
/*
* Callback function to notify the upper layer about context change
*/
EventNvmCtxChanged EventCryptoNvmCtxChanged;
}LoRaMacCryptoCtx_t;
/*
* Key-Address item
*/
typedef struct sKeyAddr
{
/*
* Address identifier
*/
AddressIdentifier_t AddrID;
/*
* Application session key
*/
KeyIdentifier_t AppSkey;
/*
* Network session key
*/
KeyIdentifier_t NwkSkey;
/*
* Rootkey (Multicast only)
*/
KeyIdentifier_t RootKey;
}KeyAddr_t;
/*
*Crypto module context.
*/
static LoRaMacCryptoCtx_t CryptoCtx;
/*
* Non volatile module context.
*/
static LoRaMacCryptoNvmCtx_t NvmCryptoCtx;
/*
* Key-Address list
*/
static KeyAddr_t KeyAddrList[NUM_OF_SEC_CTX] =
{
{ MULTICAST_0_ADDR, MC_APP_S_KEY_0, MC_NWK_S_KEY_0, MC_KEY_0 },
{ MULTICAST_1_ADDR, MC_APP_S_KEY_1, MC_NWK_S_KEY_1, MC_KEY_1 },
{ MULTICAST_2_ADDR, MC_APP_S_KEY_2, MC_NWK_S_KEY_2, MC_KEY_2 },
{ MULTICAST_3_ADDR, MC_APP_S_KEY_3, MC_NWK_S_KEY_3, MC_KEY_3 },
{ UNICAST_DEV_ADDR, APP_S_KEY, NWK_S_ENC_KEY, NO_KEY }
};
/*
* Local functions
*/
/*
* Encrypts the payload
*
* \param[IN] keyID - Key identifier
* \param[IN] address - Address
* \param[IN] dir - Frame direction ( Uplink or Downlink )
* \param[IN] frameCounter - Frame counter
* \param[IN] size - Size of data
* \param[IN/OUT] buffer - Data buffer
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t PayloadEncrypt( uint8_t* buffer, uint16_t size, KeyIdentifier_t keyID, uint32_t address, uint8_t dir, uint32_t frameCounter )
{
if( buffer == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
uint8_t bufferIndex = 0;
uint16_t ctr = 1;
uint8_t sBlock[16] = { 0 };
uint8_t aBlock[16] = { 0 };
aBlock[0] = 0x01;
aBlock[5] = dir;
aBlock[6] = address & 0xFF;
aBlock[7] = ( address >> 8 ) & 0xFF;
aBlock[8] = ( address >> 16 ) & 0xFF;
aBlock[9] = ( address >> 24 ) & 0xFF;
aBlock[10] = frameCounter & 0xFF;
aBlock[11] = ( frameCounter >> 8 ) & 0xFF;
aBlock[12] = ( frameCounter >> 16 ) & 0xFF;
aBlock[13] = ( frameCounter >> 24 ) & 0xFF;
while( size >= 16 )
{
aBlock[15] = ctr & 0xFF;
ctr++;
if( SecureElementAesEncrypt( aBlock, 16, keyID, sBlock ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
for( uint8_t i = 0; i < 16; i++ )
{
buffer[bufferIndex + i] = buffer[bufferIndex + i] ^ sBlock[i];
}
size -= 16;
bufferIndex += 16;
}
if( size > 0 )
{
aBlock[15] = ctr & 0xFF;
if( SecureElementAesEncrypt( aBlock, 16, keyID, sBlock ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
for( uint8_t i = 0; i < size; i++ )
{
buffer[bufferIndex + i] = buffer[bufferIndex + i] ^ sBlock[i];
}
}
return LORAMAC_CRYPTO_SUCCESS;
}
/*
* Encrypts the FOpts
*
* \param[IN] address - Address
* \param[IN] dir - Frame direction ( Uplink or Downlink )
* \param[IN] fCntID - Frame counter identifier
* \param[IN] frameCounter - Frame counter
* \param[IN] size - Size of data
* \param[IN/OUT] buffer - Data buffer
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t FOptsEncrypt( uint16_t size, uint32_t address, uint8_t dir, FCntIdentifier_t fCntID, uint32_t frameCounter, uint8_t* buffer )
{
if( buffer == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
uint8_t bufferIndex = 0;
uint8_t sBlock[16] = { 0 };
uint8_t aBlock[16] = { 0 };
aBlock[0] = 0x01;
switch( fCntID )
{
case FCNT_UP:
{
aBlock[4] = 0x01;
break;
}
case N_FCNT_DOWN:
{
aBlock[4] = 0x01;
break;
}
case A_FCNT_DOWN:
{
aBlock[4] = 0x02;
break;
}
default:
return LORAMAC_CRYPTO_FAIL_PARAM;
}
aBlock[5] = dir;
aBlock[6] = address & 0xFF;
aBlock[7] = ( address >> 8 ) & 0xFF;
aBlock[8] = ( address >> 16 ) & 0xFF;
aBlock[9] = ( address >> 24 ) & 0xFF;
aBlock[10] = frameCounter & 0xFF;
aBlock[11] = ( frameCounter >> 8 ) & 0xFF;
aBlock[12] = ( frameCounter >> 16 ) & 0xFF;
aBlock[13] = ( frameCounter >> 24 ) & 0xFF;
aBlock[15] = 0x01;
if( size > 0 )
{
if( SecureElementAesEncrypt( aBlock, 16, NWK_S_ENC_KEY, sBlock ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
for( uint8_t i = 0; i < size; i++ )
{
buffer[bufferIndex + i] = buffer[bufferIndex + i] ^ sBlock[i];
}
}
return LORAMAC_CRYPTO_SUCCESS;
}
/*
* Computes cmac.
*
* cmac = aes128_cmac(keyID, msg)
*
* \param[IN] msg - Message to compute the integrity code
* \param[IN] len - Length of message
* \param[IN] keyID - Key identifier
* \param[OUT] cmac - Computed cmac
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t ComputeCmac( uint8_t* msg, uint16_t len, KeyIdentifier_t keyID, uint32_t* cmac )
{
if( SecureElementComputeAesCmac( msg, len, keyID, cmac ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
return LORAMAC_CRYPTO_SUCCESS;
}
/*!
* Verifies cmac
*
* \param[IN] msg - Message to compute the integrity code
* \param[IN] len - Length of message
* \param[in] expectedCmac - Expected cmac
* \param[IN] keyID - Key identifier to determine the AES key to be used
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t VerifyCmac( uint8_t* msg, uint16_t len, KeyIdentifier_t keyID, uint32_t expectedcmac )
{
if( SecureElementVerifyAesCmac( msg, len, expectedcmac, keyID ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
return LORAMAC_CRYPTO_SUCCESS;
}
/*
* Prepares B0 block for cmac computation.
*
* \param[IN] msgLen - Length of message
* \param[IN] keyID - Key identifier
* \param[IN] isAck - True if it is a acknowledge frame ( Sets ConfFCnt in B0 block )
* \param[IN] devAddr - Device address
* \param[IN] dir - Frame direction ( Uplink:0, Downlink:1 )
* \param[IN] fCnt - Frame counter
* \param[IN/OUT] b0 - B0 block
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t PrepareB0( uint16_t msgLen, KeyIdentifier_t keyID, bool isAck, uint8_t dir, uint32_t devAddr, uint32_t fCnt, uint8_t* b0 )
{
if( b0 == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
b0[0] = 0x49;
if( isAck == true )
{
// confFCnt contains the frame counter value modulo 2^16 of the "confirmed" uplink or downlink frame that is being acknowledged
uint16_t confFCnt = 0;
if( dir == UPLINK )
{
confFCnt = ( uint16_t )( CryptoCtx.NvmCtx->FCntDown % 65536 );
}
else
{
confFCnt = ( uint16_t )( CryptoCtx.NvmCtx->FCntUp % 65536 );
}
b0[1] = confFCnt & 0xFF;
b0[2] = ( confFCnt >> 8 ) & 0xFF;
}
else
{
b0[1] = 0x00;
b0[2] = 0x00;
}
b0[3] = 0x00;
b0[4] = 0x00;
b0[5] = dir;
b0[6] = devAddr & 0xFF;
b0[7] = ( devAddr >> 8 ) & 0xFF;
b0[8] = ( devAddr >> 16 ) & 0xFF;
b0[9] = ( devAddr >> 24 ) & 0xFF;
b0[10] = fCnt & 0xFF;
b0[11] = ( fCnt >> 8 ) & 0xFF;
b0[12] = ( fCnt >> 16 ) & 0xFF;
b0[13] = ( fCnt >> 24 ) & 0xFF;
b0[14] = 0x00;
b0[15] = msgLen & 0xFF;
return LORAMAC_CRYPTO_SUCCESS;
}
/*
* Computes cmac with adding B0 block in front.
*
* cmac = aes128_cmac(keyID, B0 | msg)
*
* \param[IN] msg - Message to compute the integrity code
* \param[IN] len - Length of message
* \param[IN] keyID - Key identifier
* \param[IN] isAck - True if it is a acknowledge frame ( Sets ConfFCnt in B0 block )
* \param[IN] devAddr - Device address
* \param[IN] dir - Frame direction ( Uplink:0, Downlink:1 )
* \param[IN] fCnt - Frame counter
* \param[OUT] cmac - Computed cmac
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t ComputeCmacB0( uint8_t* msg, uint16_t len, KeyIdentifier_t keyID, bool isAck, uint8_t dir, uint32_t devAddr, uint32_t fCnt, uint32_t* cmac )
{
if( ( msg == 0 ) || ( cmac == 0 ) )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
if( len > CRYPTO_MAXMESSAGE_SIZE )
{
return LORAMAC_CRYPTO_ERROR_BUF_SIZE;
}
uint8_t micBuff[CRYPTO_BUFFER_SIZE];
memset1( micBuff, 0, CRYPTO_BUFFER_SIZE );
// Initialize the first Block
PrepareB0( len, keyID, isAck, dir, devAddr, fCnt, micBuff );
// Copy the given data to the mic computation buffer
memcpy1( ( micBuff + MIC_BLOCK_BX_SIZE ), msg, len );
if( SecureElementComputeAesCmac( micBuff, ( len + MIC_BLOCK_BX_SIZE ), keyID, cmac ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
return LORAMAC_CRYPTO_SUCCESS;
}
/*!
* Verifies cmac with adding B0 block in front.
*
* \param[IN] msg - Message to compute the integrity code
* \param[IN] len - Length of message
* \param[IN] keyID - Key identifier
* \param[IN] isAck - True if it is a acknowledge frame ( Sets ConfFCnt in B0 block )
* \param[IN] devAddr - Device address
* \param[IN] dir - Frame direction ( Uplink:0, Downlink:1 )
* \param[IN] fCnt - Frame counter
* \param[in] expectedCmac - Expected cmac
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t VerifyCmacB0( uint8_t* msg, uint16_t len, KeyIdentifier_t keyID, bool isAck, uint8_t dir, uint32_t devAddr, uint32_t fCnt, uint32_t expectedCmac )
{
if( msg == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
if( len > CRYPTO_MAXMESSAGE_SIZE )
{
return LORAMAC_CRYPTO_ERROR_BUF_SIZE;
}
uint8_t micBuff[CRYPTO_BUFFER_SIZE];
memset1( micBuff, 0, CRYPTO_BUFFER_SIZE );
// Initialize the first Block
PrepareB0( len, keyID, isAck, dir, devAddr, fCnt, micBuff );
// Copy the given data to the mic computation buffer
memcpy1( ( micBuff + MIC_BLOCK_BX_SIZE ), msg, len );
SecureElementStatus_t retval = SECURE_ELEMENT_ERROR;
retval = SecureElementVerifyAesCmac( micBuff, ( len + MIC_BLOCK_BX_SIZE ), expectedCmac, keyID );
if( retval == SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_SUCCESS;
}
else if( retval == SECURE_ELEMENT_FAIL_CMAC )
{
return LORAMAC_CRYPTO_FAIL_MIC;
}
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
/*
* Prpares B1 block for cmac computation.
*
* \param[IN] msgLen - Length of message
* \param[IN] keyID - Key identifier
* \param[IN] isAck - True if it is a acknowledge frame ( Sets ConfFCnt in B0 block )
* \param[IN] txDr - Data rate used for the transmission
* \param[IN] txCh - Index of the channel used for the transmission
* \param[IN] devAddr - Device address
* \param[IN] fCntUp - Frame counter
* \param[IN/OUT] b0 - B0 block
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t PrepareB1( uint16_t msgLen, KeyIdentifier_t keyID, bool isAck, uint8_t txDr, uint8_t txCh, uint32_t devAddr, uint32_t fCntUp, uint8_t* b1 )
{
if( b1 == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
b1[0] = 0x49;
if( isAck == true )
{
// confFCnt contains the frame counter value modulo 2^16 of the "confirmed" uplink frame that is being acknowledged
uint16_t confFCnt = ( uint16_t )( *CryptoCtx.NvmCtx->LastDownFCnt % 65536 );
b1[1] = confFCnt & 0xFF;
b1[2] = ( confFCnt >> 8 ) & 0xFF;
}
else
{
b1[1] = 0x00;
b1[2] = 0x00;
}
b1[3] = txDr;
b1[4] = txCh;
b1[5] = UPLINK; // dir = Uplink
b1[6] = devAddr & 0xFF;
b1[7] = ( devAddr >> 8 ) & 0xFF;
b1[8] = ( devAddr >> 16 ) & 0xFF;
b1[9] = ( devAddr >> 24 ) & 0xFF;
b1[10] = fCntUp & 0xFF;
b1[11] = ( fCntUp >> 8 ) & 0xFF;
b1[12] = ( fCntUp >> 16 ) & 0xFF;
b1[13] = ( fCntUp >> 24 ) & 0xFF;
b1[14] = 0x00;
b1[15] = msgLen & 0xFF;
return LORAMAC_CRYPTO_SUCCESS;
}
/*
* Computes cmac with adding B1 block in front ( only for Uplink frames LoRaWAN 1.1 )
*
* cmac = aes128_cmac(keyID, B1 | msg)
*
* \param[IN] msg - Message to calculate the Integrity code
* \param[IN] len - Length of message
* \param[IN] keyID - Key identifier
* \param[IN] isAck - True if it is a acknowledge frame ( Sets ConfFCnt in B0 block )
* \param[IN] txDr - Data rate used for the transmission
* \param[IN] txCh - Index of the channel used for the transmission
* \param[IN] devAddr - Device address
* \param[IN] fCntUp - Uplink Frame counter
* \param[OUT] cmac - Computed cmac
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t ComputeCmacB1( uint8_t* msg, uint16_t len, KeyIdentifier_t keyID, bool isAck, uint8_t txDr, uint8_t txCh, uint32_t devAddr, uint32_t fCntUp, uint32_t* cmac )
{
if( ( msg == 0 ) || ( cmac == 0 ) )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
if( len > CRYPTO_MAXMESSAGE_SIZE )
{
return LORAMAC_CRYPTO_ERROR_BUF_SIZE;
}
uint8_t micBuff[CRYPTO_BUFFER_SIZE];
memset1( micBuff, 0, CRYPTO_BUFFER_SIZE );
// Initialize the first Block
PrepareB1( len, keyID, isAck, txDr, txCh, devAddr, fCntUp, micBuff );
// Copy the given data to the mic computation buffer
memcpy1( ( micBuff + MIC_BLOCK_BX_SIZE ), msg, len );
if( SecureElementComputeAesCmac( micBuff, ( len + MIC_BLOCK_BX_SIZE ), keyID, cmac ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
return LORAMAC_CRYPTO_SUCCESS;
}
/*
* Gets security item from list.
*
* cmac = aes128_cmac(keyID, B0 | msg)
*
* \param[IN] addrID - Address identifier
* \param[OUT] keyItem - Key item reference
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t GetKeyAddrItem( AddressIdentifier_t addrID, KeyAddr_t** item )
{
for( uint8_t i = 0; i < NUM_OF_SEC_CTX; i++ )
{
if( KeyAddrList[i].AddrID == addrID )
{
*item = &( KeyAddrList[i] );
return LORAMAC_CRYPTO_SUCCESS;
}
}
return LORAMAC_CRYPTO_ERROR_INVALID_ADDR_ID;
}
/*
* Derives a session key as of LoRaWAN versions prior to 1.1.0
*
* \param[IN] keyID - Key Identifier for the key to be calculated
* \param[IN] joinNonce - Sever nonce
* \param[IN] netID - Network Identifier
* \param[IN] deviceNonce - Device nonce
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t DeriveSessionKey10x( KeyIdentifier_t keyID, uint8_t* joinNonce, uint8_t* netID, uint8_t* devNonce )
{
if( ( joinNonce == 0 ) || ( netID == 0 ) || ( devNonce == 0 ) )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
uint8_t compBase[16] = { 0 };
switch( keyID )
{
case F_NWK_S_INT_KEY:
case S_NWK_S_INT_KEY:
case NWK_S_ENC_KEY:
compBase[0] = 0x01;
break;
case APP_S_KEY:
compBase[0] = 0x02;
break;
default:
return LORAMAC_CRYPTO_ERROR_INVALID_KEY_ID;
}
memcpy1( compBase + 1, joinNonce, 3 );
memcpy1( compBase + 4, netID, 3 );
memcpy1( compBase + 7, devNonce, 2 );
if( SecureElementDeriveAndStoreKey( CryptoCtx.LrWanVersion, compBase, NWK_KEY, keyID ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
return LORAMAC_CRYPTO_SUCCESS;
}
/*
* Derives a session key as of LoRaWAN 1.1.0
*
* \param[IN] keyID - Key Identifier for the key to be calculated
* \param[IN] joinNonce - Sever nonce
* \param[IN] joinEUI - Join Server EUI
* \param[IN] deviceNonce - Device nonce
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t DeriveSessionKey11x( KeyIdentifier_t keyID, uint8_t* joinNonce, uint8_t* joinEUI, uint8_t* devNonce )
{
if( ( joinNonce == 0 ) || ( joinEUI == 0 ) || ( devNonce == 0 ) )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
uint8_t compBase[16] = { 0 };
KeyIdentifier_t rootKeyId = NWK_KEY;
switch( keyID )
{
case F_NWK_S_INT_KEY:
compBase[0] = 0x01;
break;
case S_NWK_S_INT_KEY:
compBase[0] = 0x03;
break;
case NWK_S_ENC_KEY:
compBase[0] = 0x04;
break;
case APP_S_KEY:
rootKeyId = APP_KEY;
compBase[0] = 0x02;
break;
default:
return LORAMAC_CRYPTO_ERROR_INVALID_KEY_ID;
}
memcpy1( compBase + 1, joinNonce, 3 );
memcpyr( compBase + 4, joinEUI, 8 );
memcpy1( compBase + 12, devNonce, 2 );
if( SecureElementDeriveAndStoreKey( CryptoCtx.LrWanVersion, compBase, rootKeyId, keyID ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
return LORAMAC_CRYPTO_SUCCESS;
}
/*
* Derives a life time session key (JSIntKey or JSEncKey) as of LoRaWAN 1.1.0
*
* \param[IN] keyID - Key Identifier for the key to be calculated
* \param[IN] devEUI - Device EUI
* \retval - Status of the operation
*/
static LoRaMacCryptoStatus_t DeriveLifeTimeSessionKey( KeyIdentifier_t keyID, uint8_t* devEUI )
{
if( devEUI == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
uint8_t compBase[16] = { 0 };
switch( keyID )
{
case J_S_INT_KEY:
compBase[0] = 0x06;
break;
case J_S_ENC_KEY:
compBase[0] = 0x05;
break;
default:
return LORAMAC_CRYPTO_ERROR_INVALID_KEY_ID;
}
memcpyr( compBase + 1, devEUI, 8 );
if( SecureElementDeriveAndStoreKey( CryptoCtx.LrWanVersion, compBase, NWK_KEY, keyID ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
return LORAMAC_CRYPTO_SUCCESS;
}
/*
* Checks the downlink counter value
*
* \param[IN] fCntID - Frame counter identifier
* \param[IN] currentDown - Current downlink counter value
*
* \retval - Status of the operation
*/
static bool CheckFCntDown( FCntIdentifier_t fCntID, uint32_t currentDown )
{
uint32_t lastDown = 0;
switch( fCntID )
{
case FCNT_UP:
return false;
case N_FCNT_DOWN:
lastDown = CryptoCtx.NvmCtx->NFCntDown;
CryptoCtx.NvmCtx->LastDownFCnt = &CryptoCtx.NvmCtx->NFCntDown;
break;
case A_FCNT_DOWN:
lastDown = CryptoCtx.NvmCtx->AFCntDown;
CryptoCtx.NvmCtx->LastDownFCnt = &CryptoCtx.NvmCtx->AFCntDown;
break;
case FCNT_DOWN:
lastDown = CryptoCtx.NvmCtx->FCntDown;
CryptoCtx.NvmCtx->LastDownFCnt = &CryptoCtx.NvmCtx->FCntDown;
break;
case MC_FCNT_DOWN_0:
lastDown = CryptoCtx.NvmCtx->McFCntDown0;
break;
case MC_FCNT_DOWN_1:
lastDown = CryptoCtx.NvmCtx->McFCntDown1;
break;
case MC_FCNT_DOWN_2:
lastDown = CryptoCtx.NvmCtx->McFCntDown2;
break;
case MC_FCNT_DOWN_3:
lastDown = CryptoCtx.NvmCtx->McFCntDown3;
break;
default:
return false;
}
if( ( currentDown > lastDown ) ||
// For LoRaWAN 1.0.X only. Allow downlink frames of 0
( lastDown == FCNT_DOWN_INITAL_VALUE ) )
{
return true;
}
else
{
return false;
}
}
/*!
* Updates the reference downlink counter
*
* \param[IN] fCntID - Frame counter identifier
* \param[IN] currentDown - Current downlink counter value
*
* \retval - Status of the operation
*/
static void UpdateFCntDown( FCntIdentifier_t fCntID, uint32_t currentDown )
{
switch( fCntID )
{
case N_FCNT_DOWN:
CryptoCtx.NvmCtx->NFCntDown = currentDown;
break;
case A_FCNT_DOWN:
CryptoCtx.NvmCtx->AFCntDown = currentDown;
break;
case FCNT_DOWN:
CryptoCtx.NvmCtx->FCntDown = currentDown;
break;
case MC_FCNT_DOWN_0:
CryptoCtx.NvmCtx->McFCntDown0 = currentDown;
break;
case MC_FCNT_DOWN_1:
CryptoCtx.NvmCtx->McFCntDown1 = currentDown;
break;
case MC_FCNT_DOWN_2:
CryptoCtx.NvmCtx->McFCntDown2 = currentDown;
break;
case MC_FCNT_DOWN_3:
CryptoCtx.NvmCtx->McFCntDown3 = currentDown;
break;
default:
break;
}
CryptoCtx.EventCryptoNvmCtxChanged( );
}
/*!
* Resets the frame counters
*/
void ResetFCnts( void )
{
CryptoCtx.NvmCtx->FCntUp = 0;
CryptoCtx.NvmCtx->NFCntDown = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.NvmCtx->AFCntDown = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.NvmCtx->FCntDown = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.NvmCtx->McFCntDown0 = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.NvmCtx->McFCntDown1 = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.NvmCtx->McFCntDown2 = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.NvmCtx->McFCntDown3 = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.EventCryptoNvmCtxChanged( );
}
/*
* Dummy callback in case if the user provides NULL function pointer
*/
static void DummyCB( void )
{
return;
}
/*
* API functions
*/
LoRaMacCryptoStatus_t LoRaMacCryptoInit( EventNvmCtxChanged cryptoNvmCtxChanged )
{
// Initialize volatile variables
CryptoCtx.LrWanVersion.Fields.Major = 1;
CryptoCtx.LrWanVersion.Fields.Minor = 1;
CryptoCtx.LrWanVersion.Fields.Revision = 0;
CryptoCtx.LrWanVersion.Fields.Rfu = 0;
CryptoCtx.RJcount0 = 0;
// Assign non volatile context
CryptoCtx.NvmCtx = &NvmCryptoCtx;
// Assign callback
if( cryptoNvmCtxChanged != 0 )
{
CryptoCtx.EventCryptoNvmCtxChanged = cryptoNvmCtxChanged;
}
else
{
CryptoCtx.EventCryptoNvmCtxChanged = DummyCB;
}
// Initialize with default
memset1( (uint8_t*) CryptoCtx.NvmCtx, 0, sizeof( LoRaMacCryptoNvmCtx_t ) );
// Reset frame counters
CryptoCtx.RJcount0 = 0;
CryptoCtx.NvmCtx->FCntUp = 0;
CryptoCtx.NvmCtx->FCntDown = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.NvmCtx->NFCntDown = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.NvmCtx->AFCntDown = FCNT_DOWN_INITAL_VALUE;
// Set non zero values
CryptoCtx.NvmCtx->LastDownFCnt = &CryptoCtx.NvmCtx->FCntDown;
ResetFCnts( );
return LORAMAC_CRYPTO_SUCCESS;
}
LoRaMacCryptoStatus_t LoRaMacCryptoSetLrWanVersion( Version_t version )
{
CryptoCtx.LrWanVersion = version;
return LORAMAC_CRYPTO_SUCCESS;
}
LoRaMacCryptoStatus_t LoRaMacCryptoRestoreNvmCtx( void* cryptoNvmCtx )
{
// Restore module context
if( cryptoNvmCtx != 0 )
{
memcpy1( ( uint8_t* ) &NvmCryptoCtx, ( uint8_t* ) cryptoNvmCtx, CRYPTO_NVM_CTX_SIZE );
return LORAMAC_CRYPTO_SUCCESS;
}
else
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
}
void* LoRaMacCryptoGetNvmCtx( size_t* cryptoNvmCtxSize )
{
*cryptoNvmCtxSize = CRYPTO_NVM_CTX_SIZE;
return &NvmCryptoCtx;
}
LoRaMacCryptoStatus_t LoRaMacCryptoSetKey( KeyIdentifier_t keyID, uint8_t* key )
{
if( SecureElementSetKey( keyID, key ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
return LORAMAC_CRYPTO_SUCCESS;
}
LoRaMacCryptoStatus_t LoRaMacCryptoPrepareJoinRequest( LoRaMacMessageJoinRequest_t* macMsg )
{
if( macMsg == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
KeyIdentifier_t micComputationKeyID = NWK_KEY;
LoRaMacCryptoStatus_t retval = LORAMAC_CRYPTO_ERROR;
// Add device nonce
CryptoCtx.NvmCtx->DevNonce++;
CryptoCtx.EventCryptoNvmCtxChanged( );
macMsg->DevNonce = CryptoCtx.NvmCtx->DevNonce;
// Derive lifetime session keys
retval = DeriveLifeTimeSessionKey( J_S_INT_KEY, macMsg->DevEUI );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
retval = DeriveLifeTimeSessionKey( J_S_ENC_KEY, macMsg->DevEUI );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
// Serialize message
if( LoRaMacSerializerJoinRequest( macMsg ) != LORAMAC_SERIALIZER_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SERIALIZER;
}
// Compute mic
retval = ComputeCmac( macMsg->Buffer, ( LORAMAC_JOIN_REQ_MSG_SIZE - LORAMAC_MIC_FIELD_SIZE ), micComputationKeyID, &macMsg->MIC );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
// Reserialize message to add the MIC
if( LoRaMacSerializerJoinRequest( macMsg ) != LORAMAC_SERIALIZER_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SERIALIZER;
}
return LORAMAC_CRYPTO_SUCCESS;
}
LoRaMacCryptoStatus_t LoRaMacCryptoPrepareReJoinType1( LoRaMacMessageReJoinType1_t* macMsg )
{
if( macMsg == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
// Check for RJcount1 overflow
if( CryptoCtx.NvmCtx->RJcount1 == 65535 )
{
return LORAMAC_CRYPTO_ERROR_RJCOUNT1_OVERFLOW;
}
// Serialize message
if( LoRaMacSerializerReJoinType1( macMsg ) != LORAMAC_SERIALIZER_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SERIALIZER;
}
// Compute mic
// cmac = aes128_cmac(JSIntKey, MHDR | RejoinType | JoinEUI| DevEUI | RJcount1)
LoRaMacCryptoStatus_t retval = ComputeCmac( macMsg->Buffer, ( LORAMAC_RE_JOIN_1_MSG_SIZE - LORAMAC_MIC_FIELD_SIZE ), J_S_INT_KEY, &macMsg->MIC );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
// Reserialize message to add the MIC
if( LoRaMacSerializerReJoinType1( macMsg ) != LORAMAC_SERIALIZER_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SERIALIZER;
}
// Increment RJcount1
CryptoCtx.NvmCtx->RJcount1++;
CryptoCtx.EventCryptoNvmCtxChanged( );
return LORAMAC_CRYPTO_SUCCESS;
}
LoRaMacCryptoStatus_t LoRaMacCryptoPrepareReJoinType0or2( LoRaMacMessageReJoinType0or2_t* macMsg )
{
if( macMsg == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
// Check for RJcount0 overflow
if( CryptoCtx.RJcount0 == 65535 )
{
return LORAMAC_CRYPTO_FAIL_RJCOUNT0_OVERFLOW;
}
// Serialize message
if( LoRaMacSerializerReJoinType0or2( macMsg ) != LORAMAC_SERIALIZER_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SERIALIZER;
}
// Compute mic
// cmac = aes128_cmac(SNwkSIntKey, MHDR | Rejoin Type | NetID | DevEUI | RJcount0)
LoRaMacCryptoStatus_t retval = ComputeCmac( macMsg->Buffer, ( LORAMAC_RE_JOIN_0_2_MSG_SIZE - LORAMAC_MIC_FIELD_SIZE ), S_NWK_S_INT_KEY, &macMsg->MIC );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
// Reserialize message to add the MIC
if( LoRaMacSerializerReJoinType0or2( macMsg ) != LORAMAC_SERIALIZER_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SERIALIZER;
}
// Increment RJcount0
CryptoCtx.RJcount0++;
return LORAMAC_CRYPTO_SUCCESS;
}
LoRaMacCryptoStatus_t LoRaMacCryptoHandleJoinAccept( JoinReqIdentifier_t joinReqType, uint8_t* joinEUI, LoRaMacMessageJoinAccept_t* macMsg )
{
if( ( macMsg == 0 ) || ( joinEUI == 0 ) )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
LoRaMacCryptoStatus_t retval = LORAMAC_CRYPTO_ERROR;
KeyIdentifier_t micComputationKeyID;
KeyIdentifier_t encryptionKeyID;
uint8_t micComputationOffset = 0;
uint8_t* devNonceForKeyDerivation = ( uint8_t* ) &CryptoCtx.NvmCtx->DevNonce;
// Determine decryption key and DevNonce for key derivation
if( joinReqType == JOIN_REQ )
{
encryptionKeyID = NWK_KEY;
micComputationOffset = CRYPTO_MIC_COMPUTATION_OFFSET;
}
else
{
encryptionKeyID = J_S_ENC_KEY;
// If Join-accept is a reply to a rejoin, the RJcount(0 or 1) replaces DevNonce in the key derivation process.
if( ( joinReqType == REJOIN_REQ_0 ) || ( joinReqType == REJOIN_REQ_2 ) )
{
devNonceForKeyDerivation = ( uint8_t* ) &CryptoCtx.RJcount0;
}
else
{
devNonceForKeyDerivation = ( uint8_t* ) &CryptoCtx.NvmCtx->RJcount1;
}
}
// Decrypt header, skip MHDR
uint8_t procBuffer[CRYPTO_MAXMESSAGE_SIZE + CRYPTO_MIC_COMPUTATION_OFFSET];
memset1( procBuffer, 0, ( macMsg->BufSize + micComputationOffset ) );
if( SecureElementAesEncrypt( macMsg->Buffer + LORAMAC_MHDR_FIELD_SIZE, ( macMsg->BufSize - LORAMAC_MHDR_FIELD_SIZE ), encryptionKeyID, ( procBuffer + micComputationOffset ) ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
// Copy the result to an offset location to keep space for additional information which have to be added in case of 1.1 and later
memcpy1( macMsg->Buffer + LORAMAC_MHDR_FIELD_SIZE, ( procBuffer + micComputationOffset ), ( macMsg->BufSize - LORAMAC_MHDR_FIELD_SIZE ) );
// Parse the message
if( LoRaMacParserJoinAccept( macMsg ) != LORAMAC_PARSER_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_PARSER;
}
// Is it a LoRaWAN 1.1.0 or later ?
if( macMsg->DLSettings.Bits.OptNeg == 1 )
{
CryptoCtx.LrWanVersion.Fields.Minor = 1;
micComputationKeyID = J_S_INT_KEY;
}
else
{
CryptoCtx.LrWanVersion.Fields.Minor = 0;
micComputationKeyID = NWK_KEY;
}
// Verify mic
if( CryptoCtx.LrWanVersion.Fields.Minor == 0 )
{
// For legacy mode :
// cmac = aes128_cmac(NwkKey, MHDR | JoinNonce | NetID | DevAddr | DLSettings | RxDelay | CFList | CFListType)
retval = VerifyCmac( macMsg->Buffer, ( macMsg->BufSize - LORAMAC_MIC_FIELD_SIZE ), micComputationKeyID, macMsg->MIC );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
}
else
{
// For 1.1 and later:
// cmac = aes128_cmac(JSIntKey, JoinReqType | JoinEUI | DevNonce | MHDR | JoinNonce | NetID | DevAddr | DLSettings | RxDelay | CFList | CFListType)
// Prepare the msg for integrity check (adding JoinReqType, JoinEUI and DevNonce)
uint16_t bufItr = 0;
procBuffer[bufItr++] = ( uint8_t ) joinReqType;
memcpyr( &procBuffer[bufItr], joinEUI, LORAMAC_JOIN_EUI_FIELD_SIZE );
bufItr += LORAMAC_JOIN_EUI_FIELD_SIZE;
procBuffer[bufItr++] = CryptoCtx.NvmCtx->DevNonce & 0xFF;
procBuffer[bufItr++] = ( CryptoCtx.NvmCtx->DevNonce >> 8 ) & 0xFF;
procBuffer[bufItr++] = macMsg->MHDR.Value;
retval = VerifyCmac( procBuffer, ( macMsg->BufSize + micComputationOffset - LORAMAC_MHDR_FIELD_SIZE - LORAMAC_MIC_FIELD_SIZE ), micComputationKeyID, macMsg->MIC );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
// Check if the JoinNonce is greater as the previous one
uint32_t currentJoinNonce = 0;
currentJoinNonce = ( uint32_t ) macMsg->JoinNonce[0];
currentJoinNonce |= ( ( uint32_t ) macMsg->JoinNonce[1] << 8 );
currentJoinNonce |= ( ( uint32_t ) macMsg->JoinNonce[2] << 16 );
if( currentJoinNonce > CryptoCtx.NvmCtx->JoinNonce )
{
CryptoCtx.NvmCtx->JoinNonce = currentJoinNonce;
CryptoCtx.EventCryptoNvmCtxChanged( );
}
else
{
return LORAMAC_CRYPTO_FAIL_JOIN_NONCE;
}
}
// Derive session keys
if( CryptoCtx.LrWanVersion.Fields.Minor == 1 )
{
retval = DeriveSessionKey11x( F_NWK_S_INT_KEY, macMsg->JoinNonce, joinEUI, devNonceForKeyDerivation );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
retval = DeriveSessionKey11x( S_NWK_S_INT_KEY, macMsg->JoinNonce, joinEUI, devNonceForKeyDerivation );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
retval = DeriveSessionKey11x( NWK_S_ENC_KEY, macMsg->JoinNonce, joinEUI, devNonceForKeyDerivation );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
retval = DeriveSessionKey11x( APP_S_KEY, macMsg->JoinNonce, joinEUI, devNonceForKeyDerivation );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
}
else
{
// prior LoRaWAN 1.1.0
retval = DeriveSessionKey10x( APP_S_KEY, macMsg->JoinNonce, macMsg->NetID, ( uint8_t* ) &CryptoCtx.NvmCtx->DevNonce );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
retval = DeriveSessionKey10x( NWK_S_ENC_KEY, macMsg->JoinNonce, macMsg->NetID, ( uint8_t* ) &CryptoCtx.NvmCtx->DevNonce );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
retval = DeriveSessionKey10x( F_NWK_S_INT_KEY, macMsg->JoinNonce, macMsg->NetID, ( uint8_t* ) &CryptoCtx.NvmCtx->DevNonce );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
retval = DeriveSessionKey10x( S_NWK_S_INT_KEY, macMsg->JoinNonce, macMsg->NetID, ( uint8_t* ) &CryptoCtx.NvmCtx->DevNonce );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
}
// Join-Accept is successfully processed, reset frame counters
CryptoCtx.RJcount0 = 0;
CryptoCtx.NvmCtx->FCntUp = 0;
CryptoCtx.NvmCtx->FCntDown = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.NvmCtx->NFCntDown = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.NvmCtx->AFCntDown = FCNT_DOWN_INITAL_VALUE;
CryptoCtx.EventCryptoNvmCtxChanged( );
return LORAMAC_CRYPTO_SUCCESS;
}
LoRaMacCryptoStatus_t LoRaMacCryptoSecureMessage( uint32_t fCntUp, uint8_t txDr, uint8_t txCh, LoRaMacMessageData_t* macMsg )
{
LoRaMacCryptoStatus_t retval = LORAMAC_CRYPTO_ERROR;
KeyIdentifier_t FRMPayloadDecryptionKeyID = APP_S_KEY;
if( macMsg == NULL )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
if( fCntUp < CryptoCtx.NvmCtx->FCntUp )
{
return LORAMAC_CRYPTO_FAIL_FCNT;
}
// Encrypt payload
if( macMsg->FPort == 0 )
{
// Use network session key
FRMPayloadDecryptionKeyID = NWK_S_ENC_KEY;
}
if( fCntUp > CryptoCtx.NvmCtx->FCntUp )
{
retval = PayloadEncrypt( macMsg->FRMPayload, macMsg->FRMPayloadSize, FRMPayloadDecryptionKeyID, macMsg->FHDR.DevAddr, UPLINK, fCntUp );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
if( CryptoCtx.LrWanVersion.Fields.Minor == 1 )
{
// Encrypt FOpts
retval = FOptsEncrypt( macMsg->FHDR.FCtrl.Bits.FOptsLen, macMsg->FHDR.DevAddr, UPLINK, FCNT_UP, fCntUp, macMsg->FHDR.FOpts );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
}
}
CryptoCtx.NvmCtx->FCntUp = fCntUp;
CryptoCtx.EventCryptoNvmCtxChanged( );
// Serialize message
if( LoRaMacSerializerData( macMsg ) != LORAMAC_SERIALIZER_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SERIALIZER;
}
// Compute mic
if( CryptoCtx.LrWanVersion.Fields.Minor == 1 )
{
uint32_t cmacS = 0;
uint32_t cmacF = 0;
// cmacS = aes128_cmac(SNwkSIntKey, B1 | msg)
retval = ComputeCmacB1( macMsg->Buffer, ( macMsg->BufSize - LORAMAC_MIC_FIELD_SIZE ), S_NWK_S_INT_KEY, macMsg->FHDR.FCtrl.Bits.Ack, txDr, txCh, macMsg->FHDR.DevAddr, macMsg->FHDR.FCnt, &cmacS );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
//cmacF = aes128_cmac(FNwkSIntKey, B0 | msg)
retval = ComputeCmacB0( macMsg->Buffer, ( macMsg->BufSize - LORAMAC_MIC_FIELD_SIZE ), F_NWK_S_INT_KEY, macMsg->FHDR.FCtrl.Bits.Ack, UPLINK, macMsg->FHDR.DevAddr, macMsg->FHDR.FCnt, &cmacF );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
// MIC = cmacS[0..1] | cmacF[0..1]
macMsg->MIC = ( ( cmacF << 16 ) & 0xFFFF0000 ) | ( cmacS & 0x0000FFFF );
}
else
{
// MIC = cmacF[0..3]
// The IsAck parameter is every time false since the ConfFCnt field is not used in legacy mode.
retval = ComputeCmacB0( macMsg->Buffer, ( macMsg->BufSize - LORAMAC_MIC_FIELD_SIZE ), NWK_S_ENC_KEY, false, UPLINK, macMsg->FHDR.DevAddr, macMsg->FHDR.FCnt, &macMsg->MIC );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
}
// Re-serialize message to add the MIC
if( LoRaMacSerializerData( macMsg ) != LORAMAC_SERIALIZER_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SERIALIZER;
}
return LORAMAC_CRYPTO_SUCCESS;
}
LoRaMacCryptoStatus_t LoRaMacCryptoUnsecureMessage( AddressIdentifier_t addrID, uint32_t address, FCntIdentifier_t fCntID, uint32_t fCntDown, LoRaMacMessageData_t* macMsg )
{
if( macMsg == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
if( CheckFCntDown( fCntID, fCntDown ) == false )
{
return LORAMAC_CRYPTO_FAIL_FCNT;
}
LoRaMacCryptoStatus_t retval = LORAMAC_CRYPTO_ERROR;
KeyIdentifier_t FRMPayloadDecryptionKeyID = APP_S_KEY;
KeyIdentifier_t micComputationKeyID = S_NWK_S_INT_KEY;
KeyAddr_t* curItem;
// Parse the message
if( LoRaMacParserData( macMsg ) != LORAMAC_PARSER_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_PARSER;
}
// Determine current security context
retval = GetKeyAddrItem( addrID, &curItem );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
FRMPayloadDecryptionKeyID = curItem->AppSkey;
// Check if it is our address
if( address != macMsg->FHDR.DevAddr )
{
return LORAMAC_CRYPTO_FAIL_ADDRESS;
}
// Compute mic
bool isAck = macMsg->FHDR.FCtrl.Bits.Ack;
if( CryptoCtx.LrWanVersion.Fields.Minor == 0 )
{
// In legacy mode the IsAck parameter is forced to be false since the ConfFCnt field is not used.
isAck = false;
}
// Verify mic
retval = VerifyCmacB0( macMsg->Buffer, ( macMsg->BufSize - LORAMAC_MIC_FIELD_SIZE ), micComputationKeyID, isAck, DOWNLINK, address, fCntDown, macMsg->MIC );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
// Decrypt payload
if( macMsg->FPort == 0 )
{
// Use network session encryption key
FRMPayloadDecryptionKeyID = NWK_S_ENC_KEY;
}
retval = PayloadEncrypt( macMsg->FRMPayload, macMsg->FRMPayloadSize, FRMPayloadDecryptionKeyID, address, DOWNLINK, fCntDown );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
if( CryptoCtx.LrWanVersion.Fields.Minor == 1 )
{
// Decrypt FOpts
retval = FOptsEncrypt( macMsg->FHDR.FCtrl.Bits.FOptsLen, address, DOWNLINK, fCntID, fCntDown, macMsg->FHDR.FOpts );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
}
UpdateFCntDown( fCntID, fCntDown );
return LORAMAC_CRYPTO_SUCCESS;
}
LoRaMacCryptoStatus_t LoRaMacCryptoDeriveMcKEKey( KeyIdentifier_t keyID, uint16_t nonce, uint8_t* devEUI )
{
if( devEUI == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
// Nonce SHALL be greater than 15
if( nonce < 16 )
{
return LORAMAC_CRYPTO_FAIL_PARAM;
}
// Prevent other keys than NwkKey or AppKey for LoRaWAN 1.1 or later
if( ( ( keyID == APP_KEY ) && ( CryptoCtx.LrWanVersion.Fields.Minor == 0 ) ) || ( keyID == NWK_KEY ) )
{
return LORAMAC_CRYPTO_ERROR_INVALID_KEY_ID;
}
uint8_t compBase[16] = { 0 };
compBase[0] = nonce & 0xFF;
compBase[1] = ( nonce >> 8 ) & 0xFF;
memcpyr( compBase + 2, devEUI, 8 );
if( SecureElementDeriveAndStoreKey( CryptoCtx.LrWanVersion, compBase, keyID, MC_KE_KEY ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
return LORAMAC_CRYPTO_SUCCESS;
}
LoRaMacCryptoStatus_t LoRaMacCryptoDeriveMcSessionKeyPair( AddressIdentifier_t addrID, uint32_t mcAddr )
{
if( mcAddr == 0 )
{
return LORAMAC_CRYPTO_ERROR_NPE;
}
LoRaMacCryptoStatus_t retval = LORAMAC_CRYPTO_ERROR;
// Determine current security context
KeyAddr_t* curItem;
retval = GetKeyAddrItem( addrID, &curItem );
if( retval != LORAMAC_CRYPTO_SUCCESS )
{
return retval;
}
//McAppSKey = aes128_encrypt(McKey, 0x01 | McAddr | pad16)
//McNwkSKey = aes128_encrypt(McKey, 0x02 | McAddr | pad16)
uint8_t compBaseAppS[16] = { 0 };
uint8_t compBaseNwkS[16] = { 0 };
compBaseAppS[0] = 0x01;
compBaseNwkS[0] = 0x02;
compBaseAppS[1] = mcAddr & 0xFF;
compBaseAppS[2] = ( mcAddr >> 8 ) & 0xFF;
compBaseAppS[3] = ( mcAddr >> 16 ) & 0xFF;
compBaseAppS[4] = ( mcAddr >> 24 ) & 0xFF;
compBaseNwkS[1] = mcAddr & 0xFF;
compBaseNwkS[2] = ( mcAddr >> 8 ) & 0xFF;
compBaseNwkS[3] = ( mcAddr >> 16 ) & 0xFF;
compBaseNwkS[4] = ( mcAddr >> 24 ) & 0xFF;
if( SecureElementDeriveAndStoreKey( CryptoCtx.LrWanVersion, compBaseAppS, curItem->RootKey, curItem->AppSkey ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
if( SecureElementDeriveAndStoreKey( CryptoCtx.LrWanVersion, compBaseNwkS, curItem->RootKey, curItem->NwkSkey ) != SECURE_ELEMENT_SUCCESS )
{
return LORAMAC_CRYPTO_ERROR_SECURE_ELEMENT_FUNC;
}
return LORAMAC_CRYPTO_SUCCESS;
}
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