#include "Arduino.h"
#include "sha204_library.h"
#include "sha204_lib_return_codes.h"
// atsha204Class Constructor
// Feed this function the Arduino-ized pin number you want to assign to the ATSHA204's SDA pin
// For AVR ARCH, this will find the DDRX, PORTX, and PINX registrs it'll need to point to to control that pin
// As well as the bit value for each of those registers
// For others it will only store the pin number which is used in subsequent functions
atsha204Class::atsha204Class(uint8_t pin)
{
#if defined(ARDUINO_ARCH_AVR)
device_pin = digitalPinToBitMask(pin); // Find the bit value of the pin
uint8_t port = digitalPinToPort(pin); // temoporarily used to get the next three registers
// Point to data direction register port of pin
device_port_DDR = portModeRegister(port);
// Point to output register of pin
device_port_OUT = portOutputRegister(port);
// Point to input register of pin
device_port_IN = portInputRegister(port);
#else
device_pin = pin;
#endif
}
/* Puts a the ATSHA204's unique, 4-byte serial number in the response array
returns an SHA204 Return code */
uint8_t atsha204Class::getSerialNumber(uint8_t * response)
{
uint8_t readCommand[READ_COUNT];
uint8_t readResponse[READ_4_RSP_SIZE];
/* read from bytes 0->3 of config zone */
uint8_t returnCode = sha204m_read(readCommand, readResponse, SHA204_ZONE_CONFIG, ADDRESS_SN03);
if (!returnCode) { // should return 0 if successful
for (int i=0; i<4; i++) { // store bytes 0-3 into respones array
response[i] = readResponse[SHA204_BUFFER_POS_DATA+i];
}
/* read from bytes 8->11 of config zone */
returnCode = sha204m_read(readCommand, readResponse, SHA204_ZONE_CONFIG, ADDRESS_SN47);
for (int i=4; i<8; i++) { // store bytes 4-7 of SN into response array
response[i] = readResponse[SHA204_BUFFER_POS_DATA+(i-4)];
}
if (!returnCode) {
/* Finally if last two reads were successful, read byte 8 of the SN */
returnCode = sha204m_read(readCommand, readResponse, SHA204_ZONE_CONFIG, ADDRESS_SN8);
response[8] = readResponse[SHA204_BUFFER_POS_DATA]; // Byte 8 of SN should always be 0xEE
}
}
return returnCode;
}
/* Calculates CRC16 value of provided data (and optionally including provided existing CRC16 data)
returns the calculated CRC16 value */
uint16_t atsha204Class::calculateAndUpdateCrc(uint8_t length, uint8_t *data, uint16_t current_crc)
{
uint8_t counter;
uint16_t crc_register = current_crc;
uint16_t polynom = 0x8005;
uint8_t shift_register;
uint8_t data_bit, crc_bit;
for (counter = 0; counter < length; counter++) {
for (shift_register = 0x01; shift_register > 0x00; shift_register <<= 1) {
data_bit = (data[counter] & shift_register) ? 1 : 0;
crc_bit = crc_register >> 15;
// Shift CRC to the left by 1.
crc_register <<= 1;
if ((data_bit ^ crc_bit) != 0) {
crc_register ^= polynom;
}
}
}
return crc_register;
}
/* SWI bit bang functions */
void atsha204Class::swi_set_signal_pin(uint8_t is_high)
{
SHA204_SET_OUTPUT();
if (is_high) {
SHA204_POUT_HIGH();
} else {
SHA204_POUT_LOW();
}
}
uint8_t atsha204Class::swi_send_bytes(uint8_t count, uint8_t *buffer)
{
uint8_t i, bit_mask;
// Disable interrupts while sending.
noInterrupts(); //swi_disable_interrupts();
// Set signal pin as output.
SHA204_POUT_HIGH();
SHA204_SET_OUTPUT();
// Wait turn around time.
delayMicroseconds(RX_TX_DELAY); //RX_TX_DELAY;
for (i = 0; i < count; i++) {
for (bit_mask = 1; bit_mask > 0; bit_mask <<= 1) {
if (bit_mask & buffer[i]) {
SHA204_POUT_LOW();
delayMicroseconds(BIT_DELAY); //BIT_DELAY_1;
SHA204_POUT_HIGH();
delayMicroseconds(7*BIT_DELAY); //BIT_DELAY_7;
} else {
// Send a zero bit.
SHA204_POUT_LOW();
delayMicroseconds(BIT_DELAY); //BIT_DELAY_1;
SHA204_POUT_HIGH();
delayMicroseconds(BIT_DELAY); //BIT_DELAY_1;
SHA204_POUT_LOW();
delayMicroseconds(BIT_DELAY); //BIT_DELAY_1;
SHA204_POUT_HIGH();
delayMicroseconds(5*BIT_DELAY); //BIT_DELAY_5;
}
}
}
interrupts(); //swi_enable_interrupts();
return SWI_FUNCTION_RETCODE_SUCCESS;
}
uint8_t atsha204Class::swi_send_byte(uint8_t value)
{
return swi_send_bytes(1, &value);
}
uint8_t atsha204Class::swi_receive_bytes(uint8_t count, uint8_t *buffer)
{
uint8_t status = SWI_FUNCTION_RETCODE_SUCCESS;
uint8_t i;
uint8_t bit_mask;
uint8_t pulse_count;
uint8_t timeout_count;
// Disable interrupts while receiving.
noInterrupts(); //swi_disable_interrupts();
// Configure signal pin as input
SHA204_SET_INPUT();
// Receive bits and store in buffer.
for (i = 0; i < count; i++) {
for (bit_mask = 1; bit_mask > 0; bit_mask <<= 1) {
pulse_count = 0;
// Make sure that the variable below is big enough.
// Change it to uint16_t if 255 is too small, but be aware that
// the loop resolution decreases on an 8-bit controller in that case.
timeout_count = START_PULSE_TIME_OUT;
// Detect start bit.
while (--timeout_count > 0) {
// Wait for falling edge.
if (SHA204_PIN_READ() == 0) {
break;
}
}
if (timeout_count == 0) {
status = SWI_FUNCTION_RETCODE_TIMEOUT;
break;
}
do {
// Wait for rising edge.
if (SHA204_PIN_READ() != 0) {
// For an Atmel microcontroller this might be faster than "pulse_count++".
pulse_count = 1;
break;
}
} while (--timeout_count > 0);
if (pulse_count == 0) {
status = SWI_FUNCTION_RETCODE_TIMEOUT;
break;
}
// Trying to measure the time of start bit and calculating the timeout
// for zero bit detection is not accurate enough for an 8 MHz 8-bit CPU.
// So let's just wait the maximum time for the falling edge of a zero bit
// to arrive after we have detected the rising edge of the start bit.
timeout_count = ZERO_PULSE_TIME_OUT;
// Detect possible edge indicating zero bit.
do {
if (SHA204_PIN_READ() == 0) {
// For an Atmel microcontroller this might be faster than "pulse_count++".
pulse_count = 2;
break;
}
} while (--timeout_count > 0);
// Wait for rising edge of zero pulse before returning. Otherwise we might interpret
// its rising edge as the next start pulse.
if (pulse_count == 2) {
do {
if (SHA204_PIN_READ() != 0) {
break;
}
} while (timeout_count-- > 0);
}
// Update byte at current buffer index.
else {
buffer[i] |= bit_mask; // received "one" bit
}
}
if (status != SWI_FUNCTION_RETCODE_SUCCESS) {
break;
}
}
interrupts(); //swi_enable_interrupts();
if (status == SWI_FUNCTION_RETCODE_TIMEOUT) {
if (i > 0)
// Indicate that we timed out after having received at least one byte.
{
status = SWI_FUNCTION_RETCODE_RX_FAIL;
}
}
return status;
}
/* Physical functions */
uint8_t atsha204Class::sha204p_wakeup()
{
swi_set_signal_pin(0);
delayMicroseconds(10*SHA204_WAKEUP_PULSE_WIDTH);
swi_set_signal_pin(1);
delay(SHA204_WAKEUP_DELAY);
return SHA204_SUCCESS;
}
uint8_t atsha204Class::sha204p_sleep()
{
return swi_send_byte(SHA204_SWI_FLAG_SLEEP);
}
uint8_t atsha204Class::sha204p_resync(uint8_t size, uint8_t *response)
{
delay(SHA204_SYNC_TIMEOUT);
return sha204p_receive_response(size, response);
}
uint8_t atsha204Class::sha204p_receive_response(uint8_t size, uint8_t *response)
{
uint8_t i;
uint8_t ret_code;
for (i = 0; i < size; i++) {
response[i] = 0;
}
(void) swi_send_byte(SHA204_SWI_FLAG_TX);
ret_code = swi_receive_bytes(size, response);
if (ret_code == SWI_FUNCTION_RETCODE_SUCCESS || ret_code == SWI_FUNCTION_RETCODE_RX_FAIL) {
uint8_t count_byte;
count_byte = response[SHA204_BUFFER_POS_COUNT];
if ((count_byte < SHA204_RSP_SIZE_MIN) || (count_byte > size)) {
return SHA204_INVALID_SIZE;
}
return SHA204_SUCCESS;
}
// Translate error so that the Communication layer
// can distinguish between a real error or the
// device being busy executing a command.
if (ret_code == SWI_FUNCTION_RETCODE_TIMEOUT) {
return SHA204_RX_NO_RESPONSE;
} else {
return SHA204_RX_FAIL;
}
}
uint8_t atsha204Class::sha204p_send_command(uint8_t count, uint8_t * command)
{
uint8_t ret_code = swi_send_byte(SHA204_SWI_FLAG_CMD);
if (ret_code != SWI_FUNCTION_RETCODE_SUCCESS) {
return SHA204_COMM_FAIL;
}
return swi_send_bytes(count, command);
}
/* Communication functions */
uint8_t atsha204Class::sha204c_wakeup(uint8_t *response)
{
uint8_t ret_code = sha204p_wakeup();
if (ret_code != SHA204_SUCCESS) {
return ret_code;
}
ret_code = sha204p_receive_response(SHA204_RSP_SIZE_MIN, response);
if (ret_code != SHA204_SUCCESS) {
return ret_code;
}
// Verify status response.
if (response[SHA204_BUFFER_POS_COUNT] != SHA204_RSP_SIZE_MIN) {
ret_code = SHA204_INVALID_SIZE;
} else if (response[SHA204_BUFFER_POS_STATUS] != SHA204_STATUS_BYTE_WAKEUP) {
ret_code = SHA204_COMM_FAIL;
} else {
if ((response[SHA204_RSP_SIZE_MIN - SHA204_CRC_SIZE] != 0x33)
|| (response[SHA204_RSP_SIZE_MIN + 1 - SHA204_CRC_SIZE] != 0x43)) {
ret_code = SHA204_BAD_CRC;
}
}
if (ret_code != SHA204_SUCCESS) {
delay(SHA204_COMMAND_EXEC_MAX);
}
return ret_code;
}
uint8_t atsha204Class::sha204c_resync(uint8_t size, uint8_t *response)
{
// Try to re-synchronize without sending a Wake token
// (step 1 of the re-synchronization process).
uint8_t ret_code = sha204p_resync(size, response);
if (ret_code == SHA204_SUCCESS) {
return ret_code;
}
// We lost communication. Send a Wake pulse and try
// to receive a response (steps 2 and 3 of the
// re-synchronization process).
(void) sha204p_sleep();
ret_code = sha204c_wakeup(response);
// Translate a return value of success into one
// that indicates that the device had to be woken up
// and might have lost its TempKey.
return (ret_code == SHA204_SUCCESS ? SHA204_RESYNC_WITH_WAKEUP : ret_code);
}
uint8_t atsha204Class::sha204c_send_and_receive(uint8_t *tx_buffer, uint8_t rx_size,
uint8_t *rx_buffer, uint8_t execution_delay, uint8_t execution_timeout)
{
uint8_t ret_code = SHA204_FUNC_FAIL;
uint8_t ret_code_resync;
uint8_t n_retries_send;
uint8_t n_retries_receive;
uint8_t i;
uint8_t status_byte;
uint8_t count = tx_buffer[SHA204_BUFFER_POS_COUNT];
uint8_t count_minus_crc = count - SHA204_CRC_SIZE;
uint16_t execution_timeout_us = (uint16_t) (execution_timeout * 1000) + SHA204_RESPONSE_TIMEOUT;
volatile uint16_t timeout_countdown;
// Append CRC.
sha204c_calculate_crc(count_minus_crc, tx_buffer, tx_buffer + count_minus_crc);
// Retry loop for sending a command and receiving a response.
n_retries_send = SHA204_RETRY_COUNT + 1;
while ((n_retries_send-- > 0) && (ret_code != SHA204_SUCCESS)) {
// Send command.
ret_code = sha204p_send_command(count, tx_buffer);
if (ret_code != SHA204_SUCCESS) {
if (sha204c_resync(rx_size, rx_buffer) == SHA204_RX_NO_RESPONSE) {
return ret_code; // The device seems to be dead in the water.
} else {
continue;
}
}
// Wait minimum command execution time and then start polling for a response.
delay(execution_delay);
// Retry loop for receiving a response.
n_retries_receive = SHA204_RETRY_COUNT + 1;
while (n_retries_receive-- > 0) {
// Reset response buffer.
for (i = 0; i < rx_size; i++) {
rx_buffer[i] = 0;
}
// Poll for response.
timeout_countdown = execution_timeout_us;
do {
ret_code = sha204p_receive_response(rx_size, rx_buffer);
timeout_countdown -= SHA204_RESPONSE_TIMEOUT;
} while ((timeout_countdown > SHA204_RESPONSE_TIMEOUT) && (ret_code == SHA204_RX_NO_RESPONSE));
if (ret_code == SHA204_RX_NO_RESPONSE) {
// We did not receive a response. Re-synchronize and send command again.
if (sha204c_resync(rx_size, rx_buffer) == SHA204_RX_NO_RESPONSE)
// The device seems to be dead in the water.
{
return ret_code;
} else {
break;
}
}
// Check whether we received a valid response.
if (ret_code == SHA204_INVALID_SIZE) {
// We see 0xFF for the count when communication got out of sync.
ret_code_resync = sha204c_resync(rx_size, rx_buffer);
if (ret_code_resync == SHA204_SUCCESS)
// We did not have to wake up the device. Try receiving response again.
{
continue;
}
if (ret_code_resync == SHA204_RESYNC_WITH_WAKEUP)
// We could re-synchronize, but only after waking up the device.
// Re-send command.
{
break;
} else
// We failed to re-synchronize.
{
return ret_code;
}
}
// We received a response of valid size.
// Check the consistency of the response.
ret_code = sha204c_check_crc(rx_buffer);
if (ret_code == SHA204_SUCCESS) {
// Received valid response.
if (rx_buffer[SHA204_BUFFER_POS_COUNT] > SHA204_RSP_SIZE_MIN)
// Received non-status response. We are done.
{
return ret_code;
}
// Received status response.
status_byte = rx_buffer[SHA204_BUFFER_POS_STATUS];
// Translate the three possible device status error codes
// into library return codes.
if (status_byte == SHA204_STATUS_BYTE_PARSE) {
return SHA204_PARSE_ERROR;
}
if (status_byte == SHA204_STATUS_BYTE_EXEC) {
return SHA204_CMD_FAIL;
}
if (status_byte == SHA204_STATUS_BYTE_COMM) {
// In case of the device status byte indicating a communication
// error this function exits the retry loop for receiving a response
// and enters the overall retry loop
// (send command / receive response).
ret_code = SHA204_STATUS_CRC;
break;
}
// Received status response from CheckMAC, DeriveKey, GenDig,
// Lock, Nonce, Pause, UpdateExtra, or Write command.
return ret_code;
}
else {
// Received response with incorrect CRC.
ret_code_resync = sha204c_resync(rx_size, rx_buffer);
if (ret_code_resync == SHA204_SUCCESS)
// We did not have to wake up the device. Try receiving response again.
{
continue;
}
if (ret_code_resync == SHA204_RESYNC_WITH_WAKEUP)
// We could re-synchronize, but only after waking up the device.
// Re-send command.
{
break;
} else
// We failed to re-synchronize.
{
return ret_code;
}
} // block end of check response consistency
} // block end of receive retry loop
} // block end of send and receive retry loop
return ret_code;
}
/* Marshaling functions */
uint8_t atsha204Class::sha204m_random(uint8_t * tx_buffer, uint8_t * rx_buffer, uint8_t mode)
{
if (!tx_buffer || !rx_buffer || (mode > RANDOM_NO_SEED_UPDATE)) {
return SHA204_BAD_PARAM;
}
tx_buffer[SHA204_COUNT_IDX] = RANDOM_COUNT;
tx_buffer[SHA204_OPCODE_IDX] = SHA204_RANDOM;
tx_buffer[RANDOM_MODE_IDX] = mode & RANDOM_SEED_UPDATE;
tx_buffer[RANDOM_PARAM2_IDX] =
tx_buffer[RANDOM_PARAM2_IDX + 1] = 0;
return sha204c_send_and_receive(&tx_buffer[0], RANDOM_RSP_SIZE, &rx_buffer[0], RANDOM_DELAY,
RANDOM_EXEC_MAX - RANDOM_DELAY);
}
uint8_t atsha204Class::sha204m_dev_rev(uint8_t *tx_buffer, uint8_t *rx_buffer)
{
if (!tx_buffer || !rx_buffer) {
return SHA204_BAD_PARAM;
}
tx_buffer[SHA204_COUNT_IDX] = DEVREV_COUNT;
tx_buffer[SHA204_OPCODE_IDX] = SHA204_DEVREV;
// Parameters are 0.
tx_buffer[DEVREV_PARAM1_IDX] =
tx_buffer[DEVREV_PARAM2_IDX] =
tx_buffer[DEVREV_PARAM2_IDX + 1] = 0;
return sha204c_send_and_receive(&tx_buffer[0], DEVREV_RSP_SIZE, &rx_buffer[0],
DEVREV_DELAY, DEVREV_EXEC_MAX - DEVREV_DELAY);
}
uint8_t atsha204Class::sha204m_read(uint8_t *tx_buffer, uint8_t *rx_buffer, uint8_t zone,
uint16_t address)
{
uint8_t rx_size;
if (!tx_buffer || !rx_buffer || ((zone & ~READ_ZONE_MASK) != 0)
|| ((zone & READ_ZONE_MODE_32_BYTES) && (zone == SHA204_ZONE_OTP))) {
return SHA204_BAD_PARAM;
}
address >>= 2;
if ((zone & SHA204_ZONE_MASK) == SHA204_ZONE_CONFIG) {
if (address > SHA204_ADDRESS_MASK_CONFIG) {
return SHA204_BAD_PARAM;
}
} else if ((zone & SHA204_ZONE_MASK) == SHA204_ZONE_OTP) {
if (address > SHA204_ADDRESS_MASK_OTP) {
return SHA204_BAD_PARAM;
}
} else if ((zone & SHA204_ZONE_MASK) == SHA204_ZONE_DATA) {
if (address > SHA204_ADDRESS_MASK) {
return SHA204_BAD_PARAM;
}
}
tx_buffer[SHA204_COUNT_IDX] = READ_COUNT;
tx_buffer[SHA204_OPCODE_IDX] = SHA204_READ;
tx_buffer[READ_ZONE_IDX] = zone;
tx_buffer[READ_ADDR_IDX] = (uint8_t) (address & SHA204_ADDRESS_MASK);
tx_buffer[READ_ADDR_IDX + 1] = 0;
rx_size = (zone & SHA204_ZONE_COUNT_FLAG) ? READ_32_RSP_SIZE : READ_4_RSP_SIZE;
return sha204c_send_and_receive(&tx_buffer[0], rx_size, &rx_buffer[0], READ_DELAY,
READ_EXEC_MAX - READ_DELAY);
}
uint8_t atsha204Class::sha204m_execute(uint8_t op_code, uint8_t param1, uint16_t param2,
uint8_t datalen1, uint8_t *data1, uint8_t datalen2, uint8_t *data2, uint8_t datalen3,
uint8_t *data3,
uint8_t tx_size, uint8_t *tx_buffer, uint8_t rx_size, uint8_t *rx_buffer)
{
uint8_t poll_delay, poll_timeout, response_size;
uint8_t *p_buffer;
uint8_t len;
uint8_t ret_code = sha204m_check_parameters(op_code, param1, param2,
datalen1, data1, datalen2, data2, datalen3, data3,
tx_size, tx_buffer, rx_size, rx_buffer);
if (ret_code != SHA204_SUCCESS) {
return ret_code;
}
// Supply delays and response size.
switch (op_code) {
case SHA204_CHECKMAC:
poll_delay = CHECKMAC_DELAY;
poll_timeout = CHECKMAC_EXEC_MAX - CHECKMAC_DELAY;
response_size = CHECKMAC_RSP_SIZE;
break;
case SHA204_DERIVE_KEY:
poll_delay = DERIVE_KEY_DELAY;
poll_timeout = DERIVE_KEY_EXEC_MAX - DERIVE_KEY_DELAY;
response_size = DERIVE_KEY_RSP_SIZE;
break;
case SHA204_DEVREV:
poll_delay = DEVREV_DELAY;
poll_timeout = DEVREV_EXEC_MAX - DEVREV_DELAY;
response_size = DEVREV_RSP_SIZE;
break;
case SHA204_GENDIG:
poll_delay = GENDIG_DELAY;
poll_timeout = GENDIG_EXEC_MAX - GENDIG_DELAY;
response_size = GENDIG_RSP_SIZE;
break;
case SHA204_HMAC:
poll_delay = HMAC_DELAY;
poll_timeout = HMAC_EXEC_MAX - HMAC_DELAY;
response_size = HMAC_RSP_SIZE;
break;
case SHA204_LOCK:
poll_delay = LOCK_DELAY;
poll_timeout = LOCK_EXEC_MAX - LOCK_DELAY;
response_size = LOCK_RSP_SIZE;
break;
case SHA204_MAC:
poll_delay = MAC_DELAY;
poll_timeout = MAC_EXEC_MAX - MAC_DELAY;
response_size = MAC_RSP_SIZE;
break;
case SHA204_NONCE:
poll_delay = NONCE_DELAY;
poll_timeout = NONCE_EXEC_MAX - NONCE_DELAY;
response_size = param1 == NONCE_MODE_PASSTHROUGH
? NONCE_RSP_SIZE_SHORT : NONCE_RSP_SIZE_LONG;
break;
case SHA204_PAUSE:
poll_delay = PAUSE_DELAY;
poll_timeout = PAUSE_EXEC_MAX - PAUSE_DELAY;
response_size = PAUSE_RSP_SIZE;
break;
case SHA204_RANDOM:
poll_delay = RANDOM_DELAY;
poll_timeout = RANDOM_EXEC_MAX - RANDOM_DELAY;
response_size = RANDOM_RSP_SIZE;
break;
case SHA204_READ:
poll_delay = READ_DELAY;
poll_timeout = READ_EXEC_MAX - READ_DELAY;
response_size = (param1 & SHA204_ZONE_COUNT_FLAG)
? READ_32_RSP_SIZE : READ_4_RSP_SIZE;
break;
case SHA204_UPDATE_EXTRA:
poll_delay = UPDATE_DELAY;
poll_timeout = UPDATE_EXEC_MAX - UPDATE_DELAY;
response_size = UPDATE_RSP_SIZE;
break;
case SHA204_WRITE:
poll_delay = WRITE_DELAY;
poll_timeout = WRITE_EXEC_MAX - WRITE_DELAY;
response_size = WRITE_RSP_SIZE;
break;
default:
poll_delay = 0;
poll_timeout = SHA204_COMMAND_EXEC_MAX;
response_size = rx_size;
}
// Assemble command.
len = datalen1 + datalen2 + datalen3 + SHA204_CMD_SIZE_MIN;
p_buffer = tx_buffer;
*p_buffer++ = len;
*p_buffer++ = op_code;
*p_buffer++ = param1;
*p_buffer++ = param2 & 0xFF;
*p_buffer++ = param2 >> 8;
if (datalen1 > 0) {
memcpy(p_buffer, data1, datalen1);
p_buffer += datalen1;
}
if (datalen2 > 0) {
memcpy(p_buffer, data2, datalen2);
p_buffer += datalen2;
}
if (datalen3 > 0) {
memcpy(p_buffer, data3, datalen3);
p_buffer += datalen3;
}
sha204c_calculate_crc(len - SHA204_CRC_SIZE, tx_buffer, p_buffer);
// Send command and receive response.
return sha204c_send_and_receive(&tx_buffer[0], response_size,
&rx_buffer[0], poll_delay, poll_timeout);
}
uint8_t atsha204Class::sha204m_check_parameters(uint8_t op_code, uint8_t param1, uint16_t param2,
uint8_t datalen1, uint8_t *data1, uint8_t datalen2, uint8_t *data2, uint8_t datalen3,
uint8_t *data3,
uint8_t tx_size, uint8_t *tx_buffer, uint8_t rx_size, uint8_t *rx_buffer)
{
#ifdef SHA204_CHECK_PARAMETERS
uint8_t len = datalen1 + datalen2 + datalen3 + SHA204_CMD_SIZE_MIN;
if (!tx_buffer || tx_size < len || rx_size < SHA204_RSP_SIZE_MIN || !rx_buffer) {
return SHA204_BAD_PARAM;
}
if ((datalen1 > 0 && !data1) || (datalen2 > 0 && !data2) || (datalen3 > 0 && !data3)) {
return SHA204_BAD_PARAM;
}
// Check parameters depending on op-code.
switch (op_code) {
case SHA204_CHECKMAC:
if (
// no null pointers allowed
!data1 || !data2
// No reserved bits should be set.
|| (param1 | CHECKMAC_MODE_MASK) != CHECKMAC_MODE_MASK
// key_id > 15 not allowed
|| param2 > SHA204_KEY_ID_MAX
) {
return SHA204_BAD_PARAM;
}
break;
case SHA204_DERIVE_KEY:
if (param2 > SHA204_KEY_ID_MAX) {
return SHA204_BAD_PARAM;
}
break;
case SHA204_DEVREV:
break;
case SHA204_GENDIG:
if ((param1 != GENDIG_ZONE_OTP) && (param1 != GENDIG_ZONE_DATA)) {
return SHA204_BAD_PARAM;
}
break;
case SHA204_HMAC:
if ((param1 & ~HMAC_MODE_MASK) != 0) {
return SHA204_BAD_PARAM;
}
break;
case SHA204_LOCK:
if (((param1 & ~LOCK_ZONE_MASK) != 0)
|| ((param1 & LOCK_ZONE_NO_CRC) && (param2 != 0))) {
return SHA204_BAD_PARAM;
}
break;
case SHA204_MAC:
if (((param1 & ~MAC_MODE_MASK) != 0)
|| (((param1 & MAC_MODE_BLOCK2_TEMPKEY) == 0) && !data1)) {
return SHA204_BAD_PARAM;
}
break;
case SHA204_NONCE:
if ( !data1
|| (param1 > NONCE_MODE_PASSTHROUGH)
|| (param1 == NONCE_MODE_INVALID)
) {
return SHA204_BAD_PARAM;
}
break;
case SHA204_PAUSE:
break;
case SHA204_RANDOM:
if (param1 > RANDOM_NO_SEED_UPDATE) {
return SHA204_BAD_PARAM;
}
break;
case SHA204_READ:
if (((param1 & ~READ_ZONE_MASK) != 0)
|| ((param1 & READ_ZONE_MODE_32_BYTES) && (param1 == SHA204_ZONE_OTP))) {
return SHA204_BAD_PARAM;
}
break;
case SHA204_TEMPSENSE:
break;
case SHA204_UPDATE_EXTRA:
if (param1 > UPDATE_CONFIG_BYTE_86) {
return SHA204_BAD_PARAM;
}
break;
case SHA204_WRITE:
if (!data1 || ((param1 & ~WRITE_ZONE_MASK) != 0)) {
return SHA204_BAD_PARAM;
}
break;
default:
// unknown op-code
return SHA204_BAD_PARAM;
}
return SHA204_SUCCESS;
#else
(void)rx_size;
(void)tx_size;
(void)tx_buffer;
(void)rx_buffer;
(void)param1;
(void)param2;
(void)data1;
(void)data2;
(void)data3;
(void)datalen1;
(void)datalen2;
(void)datalen3;
(void)op_code;
return SHA204_SUCCESS;
#endif
}
/* CRC Calculator and Checker */
void atsha204Class::sha204c_calculate_crc(uint8_t length, uint8_t *data, uint8_t *crc)
{
uint16_t crc_register = 0;
crc_register = calculateAndUpdateCrc(length, data, crc_register);
crc[0] = (uint8_t) (crc_register & 0x00FF);
crc[1] = (uint8_t) (crc_register >> 8);
}
uint8_t atsha204Class::sha204c_check_crc(uint8_t *response)
{
uint8_t crc[SHA204_CRC_SIZE];
uint8_t count = response[SHA204_BUFFER_POS_COUNT];
count -= SHA204_CRC_SIZE;
sha204c_calculate_crc(count, response, crc);
return (crc[0] == response[count] && crc[1] == response[count + 1])
? SHA204_SUCCESS : SHA204_BAD_CRC;
}