diff --git a/libraries/MySensors/MyConfig.h b/libraries/MySensors/MyConfig.h index ce4f0aa..82c02da 100644 --- a/libraries/MySensors/MyConfig.h +++ b/libraries/MySensors/MyConfig.h @@ -17,6 +17,7 @@ // Choose signing backend by enabling one of the following #define MYSENSORS_SIGNING_DUMMY +//#define MYSENSORS_SIGNING_ATSHA204 // Define a suitable timeout for a signature verification session // Consider the turnaround from a nonce being generated to a signed message being received @@ -39,6 +40,24 @@ typedef class MyRFDriverRF69 MyRFDriverClass; typedef class MySigningDriverDummy MySigningDriverClass; #endif +#ifdef MYSENSORS_SIGNING_ATSHA204 +#ifdef MYSENSORS_SENSOR +#define ATSHA204_PIN 17 //A3 +#endif + +#ifdef MYSENSORS_SERIAL_GATEWAY +#define ATSHA204_PIN 17 //A3 +#endif + +#ifdef MYSENSORS_ETHERNET_MQTT_GATEWAY +#define ATSHA204_PIN 17 //A3 +#endif + +#include "MySigningDriverAtsha204.h" +#define SIGNING_IDENTIFIER (1) // SHA256-based HMAC (ATSHA204 specific) +typedef class MySigningDriverAtsha204 MySigningDriverClass; +#endif + /*** * Enable/Disable debug logging */ diff --git a/libraries/MySensors/MySigningDriverAtsha204.cpp b/libraries/MySensors/MySigningDriverAtsha204.cpp new file mode 100644 index 0000000..a71a30a --- /dev/null +++ b/libraries/MySensors/MySigningDriverAtsha204.cpp @@ -0,0 +1,217 @@ +/* + ATSHA204 signing backend. The Atmel ATSHA204 offers true random number generation and + HMAC-SHA256 authentication with a readout-protected key. + + Created by Patrick "Anticimex" Fallberg +*/ +#include "MySigningDriver.h" +#include "MySigningDriverAtsha204.h" + +#ifdef MYSENSORS_SIGNING_ATSHA204 +// Uncomment this to get some useful serial debug info (Serial.print and Serial.println expected) +//#define DEBUG_ATSHA_SIGNING + +#ifdef DEBUG_ATSHA_SIGNING +#define DEBUG_ATSHA_PRINTLN(args) Serial.println(args) +#else +#define DEBUG_ATSHA_PRINTLN(args) +#endif + +#ifdef DEBUG_ATSHA_SIGNING +static void DEBUG_ATSHA_PRINTBUF(char* str, uint8_t* buf, uint8_t sz) +{ + int i; + Serial.println(str); + for (int i=0; i timestamp + VERIFICATION_TIMEOUT_MS) { + DEBUG_ATSHA_PRINTLN("Verification timeout"); + // Purge nonce + memset(current_nonce, 0xAA, NONCE_NUMIN_SIZE_PASSTHROUGH); + verification_ongoing = false; + return false; + } + } + return true; +} + +bool MySigningDriverAtsha204::putNonce(MyMessage &msg) { + if (mGetLength(msg) != MAX_PAYLOAD) { + DEBUG_ATSHA_PRINTLN("Incoming nonce with incorrect size"); + return false; // We require as big nonce as possible + } + + if (((uint8_t*)msg.getCustom())[0] != SIGNING_IDENTIFIER) { + DEBUG_ATSHA_PRINTLN("Incorrect signing identifier"); + return false; + } + + memcpy(current_nonce, (uint8_t*)msg.getCustom(), MAX_PAYLOAD); + return true; +} + +bool MySigningDriverAtsha204::signMsg(MyMessage &msg) { + // If we cannot fit any signature in the message, refuse to sign it + if (mGetLength(msg) > MAX_PAYLOAD-2) { + DEBUG_ATSHA_PRINTLN("Cannot fit any signature to this message"); + return false; + } + + // Calculate signature of message + mSetSigned(msg, 1); // make sure signing flag is set before signature is calculated + DEBUG_ATSHA_PRINTBUF("Message to sign:", (uint8_t*)&msg.data[1-HEADER_SIZE], MAX_MESSAGE_LENGTH-1-(MAX_PAYLOAD-mGetLength(msg))); + if (!calculateSignature(msg)) { + DEBUG_ATSHA_PRINTLN("Failed to calculate signature"); + mSetSigned(msg, 0); // make sure signing flag is truthful + return false; + } + + // Transfer as much signature data as the remaining space in the message permits + memcpy(&msg.data[mGetLength(msg)], &rx_buffer[SHA204_BUFFER_POS_DATA], MAX_PAYLOAD-mGetLength(msg)); + + return true; +} + +bool MySigningDriverAtsha204::verifyMsg(MyMessage &msg) { + if (!verification_ongoing) { + DEBUG_ATSHA_PRINTLN("No active verification session"); + return false; + } else { + // Make sure we have not expired + if (!checkTimer()) { + return false; + } + + verification_ongoing = false; + + if (msg.data[mGetLength(msg)] != SIGNING_IDENTIFIER) { + DEBUG_ATSHA_PRINTLN("Incorrect signing identifier"); + return false; + } + + DEBUG_ATSHA_PRINTBUF("Message to verify:", (uint8_t*)&msg.data[1-HEADER_SIZE], MAX_MESSAGE_LENGTH-1-(MAX_PAYLOAD-mGetLength(msg))); + DEBUG_ATSHA_PRINTBUF("Signature in message:", (uint8_t*)&msg.data[mGetLength(msg)], MAX_PAYLOAD-mGetLength(msg)); + + // Get signature of message + if (!calculateSignature(msg)) { + DEBUG_ATSHA_PRINTLN("Failed to calculate signature"); + return false; + } + + // Compare the caluclated signature with the provided signature + if (memcmp(&msg.data[mGetLength(msg)], &rx_buffer[SHA204_BUFFER_POS_DATA], MAX_PAYLOAD-mGetLength(msg))) { + DEBUG_ATSHA_PRINTBUF("Signature bad. Calculated signature:", &rx_buffer[SHA204_BUFFER_POS_DATA], MAX_PAYLOAD-mGetLength(msg)); + return false; + } else { + DEBUG_ATSHA_PRINTLN("Signature ok"); + return true; + } + } +} + +// Helper to calculate signature of msg (returned in rx_buffer[SHA204_BUFFER_POS_DATA]) +bool MySigningDriverAtsha204::calculateSignature(MyMessage &msg) { + memset(temp_message, 0, 32); + memcpy(temp_message, (uint8_t*)&msg.data[1-HEADER_SIZE], MAX_MESSAGE_LENGTH-1-(MAX_PAYLOAD-mGetLength(msg))); + + // Wake device before starting operations + if (atsha204.sha204c_wakeup(rx_buffer) != SHA204_SUCCESS) return false; + + // Program the data to sign into the ATSHA204 + if (atsha204.sha204m_execute(SHA204_WRITE, SHA204_ZONE_DATA | SHA204_ZONE_COUNT_FLAG, 8 << 3, 32, temp_message, + WRITE_COUNT_LONG, tx_buffer, WRITE_RSP_SIZE, rx_buffer) != SHA204_SUCCESS) { + DEBUG_ATSHA_PRINTLN("Failed to program data"); + return false; + } + + // Program the nonce to use for the signature (has to be done just before GENDIG due to chip limitations) + if (atsha204.sha204m_execute(SHA204_NONCE, NONCE_MODE_PASSTHROUGH, 0, NONCE_NUMIN_SIZE_PASSTHROUGH, current_nonce, + NONCE_COUNT_LONG, tx_buffer, NONCE_RSP_SIZE_SHORT, rx_buffer) != SHA204_SUCCESS) { + DEBUG_ATSHA_PRINTLN("Failed to program nonce"); + // Purge nonce when used + memset(current_nonce, 0xAA, NONCE_NUMIN_SIZE_PASSTHROUGH); + return false; + } + + // Purge nonce when used + memset(current_nonce, 0xAA, NONCE_NUMIN_SIZE_PASSTHROUGH); + + // Generate digest of data and nonce + if (atsha204.sha204m_execute(SHA204_GENDIG, GENDIG_ZONE_DATA, 8, 0, NULL, + GENDIG_COUNT_DATA, tx_buffer, GENDIG_RSP_SIZE, rx_buffer) != SHA204_SUCCESS) { + DEBUG_ATSHA_PRINTLN("Failed to generate digest"); + return false; + } + + // Calculate HMAC of message+nonce digest and secret key + if (atsha204.sha204m_execute(SHA204_HMAC, HMAC_MODE_SOURCE_FLAG_MATCH, 0, 0, NULL, + HMAC_COUNT, tx_buffer, HMAC_RSP_SIZE, rx_buffer) != SHA204_SUCCESS) { + DEBUG_ATSHA_PRINTLN("Failed to generate HMAC"); + return false; + } + + // Put device back to sleep + atsha204.sha204c_sleep(); + + // Overwrite the first byte in the signature with the signing identifier + rx_buffer[SHA204_BUFFER_POS_DATA] = SIGNING_IDENTIFIER; + + DEBUG_ATSHA_PRINTBUF("HMAC:", &rx_buffer[SHA204_BUFFER_POS_DATA], 32); + return true; // We return with the signature in rx_buffer[SHA204_BUFFER_POS_DATA] +} +#endif diff --git a/libraries/MySensors/MySigningDriverAtsha204.h b/libraries/MySensors/MySigningDriverAtsha204.h new file mode 100644 index 0000000..a2f6b9d --- /dev/null +++ b/libraries/MySensors/MySigningDriverAtsha204.h @@ -0,0 +1,37 @@ +/* + ATSHA204 signing backend. The Atmel ATSHA204 offers true random number generation and + HMAC-SHA256 authentication with a readout-protected key. + + Created by Patrick "Anticimex" Fallberg +*/ +#ifndef MySigningDriverAtsha204_h +#define MySigningDriverAtsha204_h + +#include "MyConfig.h" +#include "MySigningDriver.h" +#include "utility/ATSHA204.h" +#include + +// The ATSHA204 is capable of generating proper random numbers for nonce +// and can calculate HMAC-SHA256 signatures. This is enterprise- +// level of security and ought to implement the signing needs for anybody. +class MySigningDriverAtsha204 : public MySigningDriver +{ +public: + MySigningDriverAtsha204(); + bool getNonce(MyMessage &msg); + bool checkTimer(void); + bool putNonce(MyMessage &msg); + bool signMsg(MyMessage &msg); + bool verifyMsg(MyMessage &msg); +private: + unsigned long timestamp; + bool verification_ongoing; + uint8_t current_nonce[NONCE_NUMIN_SIZE_PASSTHROUGH]; + uint8_t temp_message[32]; + uint8_t rx_buffer[SHA204_RSP_SIZE_MAX]; + uint8_t tx_buffer[SHA204_CMD_SIZE_MAX]; + bool calculateSignature(MyMessage &msg); +}; + +#endif diff --git a/libraries/MySensors/utility/ATSHA204.cpp b/libraries/MySensors/utility/ATSHA204.cpp new file mode 100644 index 0000000..da63668 --- /dev/null +++ b/libraries/MySensors/utility/ATSHA204.cpp @@ -0,0 +1,521 @@ +#include "Arduino.h" +#include "ATSHA204.h" + +// atsha204Class Constructor +// Feed this function the Arduino-ized pin number you want to assign to the ATSHA204's SDA pin +// 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 +atsha204Class::atsha204Class(uint8_t pin) +{ + 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); +} + +/* SWI bit bang functions */ + +void atsha204Class::swi_set_signal_pin(uint8_t is_high) +{ + *device_port_DDR |= device_pin; + + if (is_high) + *device_port_OUT |= device_pin; + else + *device_port_OUT &= ~device_pin; +} + +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. + *device_port_OUT |= device_pin; + *device_port_DDR |= device_pin; + + // 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]) + { + *device_port_OUT &= ~device_pin; + delayMicroseconds(BIT_DELAY); //BIT_DELAY_1; + *device_port_OUT |= device_pin; + delayMicroseconds(7*BIT_DELAY); //BIT_DELAY_7; + } + else + { + // Send a zero bit. + *device_port_OUT &= ~device_pin; + delayMicroseconds(BIT_DELAY); //BIT_DELAY_1; + *device_port_OUT |= device_pin; + delayMicroseconds(BIT_DELAY); //BIT_DELAY_1; + *device_port_OUT &= ~device_pin; + delayMicroseconds(BIT_DELAY); //BIT_DELAY_1; + *device_port_OUT |= device_pin; + 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. + *device_port_DDR &= ~device_pin; + + // 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 ((*device_port_IN & device_pin) == 0) + break; + } + + if (timeout_count == 0) + { + status = SWI_FUNCTION_RETCODE_TIMEOUT; + break; + } + + do + { + // Wait for rising edge. + if ((*device_port_IN & device_pin) != 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 ((*device_port_IN & device_pin) == 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 ((*device_port_IN & device_pin) != 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::sha204c_sleep() +{ + return swi_send_byte(SHA204_SWI_FLAG_SLEEP); +} + +uint8_t atsha204Class::sha204p_receive_response(uint8_t size, uint8_t *response) +{ + uint8_t count_byte; + 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) + { + 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; +} + +/* Communication functions */ + +uint8_t atsha204Class::sha204c_wakeup(uint8_t *response) +{ + swi_set_signal_pin(0); + delayMicroseconds(10*SHA204_WAKEUP_PULSE_WIDTH); + swi_set_signal_pin(1); + delay(SHA204_WAKEUP_DELAY); + + uint8_t 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). + delay(SHA204_SYNC_TIMEOUT); + uint8_t ret_code = sha204p_receive_response(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) sha204c_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 = swi_send_byte(SHA204_SWI_FLAG_CMD); + if (ret_code != SWI_FUNCTION_RETCODE_SUCCESS) + ret_code = SHA204_COMM_FAIL; + else + ret_code = swi_send_bytes(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_execute(uint8_t op_code, uint8_t param1, uint16_t param2, + uint8_t datalen1, uint8_t *data1, 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; + + // Supply delays and response size. + switch (op_code) + { + 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_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_RANDOM: + poll_delay = RANDOM_DELAY; + poll_timeout = RANDOM_EXEC_MAX - RANDOM_DELAY; + response_size = RANDOM_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 + 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; + } + + 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); +} + +/* CRC Calculator and Checker */ + +void atsha204Class::sha204c_calculate_crc(uint8_t length, uint8_t *data, uint8_t *crc) +{ + uint8_t counter; + uint16_t crc_register = 0; + 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; + } + } + 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; +} \ No newline at end of file diff --git a/libraries/MySensors/utility/ATSHA204.h b/libraries/MySensors/utility/ATSHA204.h new file mode 100644 index 0000000..cb2abc8 --- /dev/null +++ b/libraries/MySensors/utility/ATSHA204.h @@ -0,0 +1,206 @@ +#ifndef ATSHA204_H +#define ATSHA204_H +#include "Arduino.h" + +/* This is a scaled down variant of the ATSHA204 library, tweaked to meet the specific needs of MySensors. */ + +/* Library return codes */ +#define SHA204_SUCCESS ((uint8_t) 0x00) //!< Function succeeded. +#define SHA204_PARSE_ERROR ((uint8_t) 0xD2) //!< response status byte indicates parsing error +#define SHA204_CMD_FAIL ((uint8_t) 0xD3) //!< response status byte indicates command execution error +#define SHA204_STATUS_CRC ((uint8_t) 0xD4) //!< response status byte indicates CRC error +#define SHA204_STATUS_UNKNOWN ((uint8_t) 0xD5) //!< response status byte is unknown +#define SHA204_FUNC_FAIL ((uint8_t) 0xE0) //!< Function could not execute due to incorrect condition / state. +#define SHA204_GEN_FAIL ((uint8_t) 0xE1) //!< unspecified error +#define SHA204_BAD_PARAM ((uint8_t) 0xE2) //!< bad argument (out of range, null pointer, etc.) +#define SHA204_INVALID_ID ((uint8_t) 0xE3) //!< invalid device id, id not set +#define SHA204_INVALID_SIZE ((uint8_t) 0xE4) //!< Count value is out of range or greater than buffer size. +#define SHA204_BAD_CRC ((uint8_t) 0xE5) //!< incorrect CRC received +#define SHA204_RX_FAIL ((uint8_t) 0xE6) //!< Timed out while waiting for response. Number of bytes received is > 0. +#define SHA204_RX_NO_RESPONSE ((uint8_t) 0xE7) //!< Not an error while the Command layer is polling for a command response. +#define SHA204_RESYNC_WITH_WAKEUP ((uint8_t) 0xE8) //!< re-synchronization succeeded, but only after generating a Wake-up + +#define SHA204_COMM_FAIL ((uint8_t) 0xF0) //!< Communication with device failed. Same as in hardware dependent modules. +#define SHA204_TIMEOUT ((uint8_t) 0xF1) //!< Timed out while waiting for response. Number of bytes received is 0. + +/* bitbang_config.h */ + +#define PORT_ACCESS_TIME (630) //! time it takes to toggle the pin at CPU clock of 16 MHz (ns) +#define START_PULSE_WIDTH (4340) //! width of start pulse (ns) +#define BIT_DELAY (4) //! delay macro for width of one pulse (start pulse or zero pulse, in ns) +#define RX_TX_DELAY (15) //! turn around time when switching from receive to transmit +#define START_PULSE_TIME_OUT (255) //! This value is decremented while waiting for the falling edge of a start pulse. +#define ZERO_PULSE_TIME_OUT (26) //! This value is decremented while waiting for the falling edge of a zero pulse. + +/* swi_phys.h */ + +#define SWI_FUNCTION_RETCODE_SUCCESS ((uint8_t) 0x00) //!< Communication with device succeeded. +#define SWI_FUNCTION_RETCODE_TIMEOUT ((uint8_t) 0xF1) //!< Communication timed out. +#define SWI_FUNCTION_RETCODE_RX_FAIL ((uint8_t) 0xF9) //!< Communication failed after at least one byte was received. + +/* sha204_physical.h */ + +#define SHA204_RSP_SIZE_MIN ((uint8_t) 4) //!< minimum number of bytes in response +#define SHA204_RSP_SIZE_MAX ((uint8_t) 35) //!< maximum size of response packet +#define SHA204_BUFFER_POS_COUNT (0) //!< buffer index of count byte in command or response +#define SHA204_BUFFER_POS_DATA (1) //!< buffer index of data in response +#define SHA204_WAKEUP_PULSE_WIDTH (uint8_t) (6.0 * CPU_CLOCK_DEVIATION_POSITIVE + 0.5) //! width of Wakeup pulse in 10 us units +#define SHA204_WAKEUP_DELAY (uint8_t) (3.0 * CPU_CLOCK_DEVIATION_POSITIVE + 0.5) //! delay between Wakeup pulse and communication in ms + +/* sha204_swi.c */ +#define SHA204_SWI_FLAG_CMD ((uint8_t) 0x77) //!< flag preceding a command +#define SHA204_SWI_FLAG_TX ((uint8_t) 0x88) //!< flag requesting a response +#define SHA204_SWI_FLAG_IDLE ((uint8_t) 0xBB) //!< flag requesting to go into Idle mode +#define SHA204_SWI_FLAG_SLEEP ((uint8_t) 0xCC) //!< flag requesting to go into Sleep mode + +/* sha204_comm_marshaling.h */ +// command op-code definitions +#define SHA204_GENDIG ((uint8_t) 0x15) //!< GenDig command op-code +#define SHA204_HMAC ((uint8_t) 0x11) //!< HMAC command op-code +#define SHA204_NONCE ((uint8_t) 0x16) //!< Nonce command op-code +#define SHA204_RANDOM ((uint8_t) 0x1B) //!< Random command op-code +#define SHA204_WRITE ((uint8_t) 0x12) //!< Write command op-code + +// packet size definitions +#define SHA204_RSP_SIZE_VAL ((uint8_t) 7) //!< size of response packet containing four bytes of data + +// definitions for command packet indexes common to all commands +#define SHA204_COUNT_IDX ( 0) //!< command packet index for count +#define SHA204_OPCODE_IDX ( 1) //!< command packet index for op-code +#define SHA204_PARAM1_IDX ( 2) //!< command packet index for first parameter +#define SHA204_PARAM2_IDX ( 3) //!< command packet index for second parameter +#define SHA204_DATA_IDX ( 5) //!< command packet index for second parameter + +// zone definitions +#define SHA204_ZONE_CONFIG ((uint8_t) 0x00) //!< Configuration zone +#define SHA204_ZONE_OTP ((uint8_t) 0x01) //!< OTP (One Time Programming) zone +#define SHA204_ZONE_DATA ((uint8_t) 0x02) //!< Data zone +#define SHA204_ZONE_MASK ((uint8_t) 0x03) //!< Zone mask +#define SHA204_ZONE_COUNT_FLAG ((uint8_t) 0x80) //!< Zone bit 7 set: Access 32 bytes, otherwise 4 bytes. +#define SHA204_ZONE_ACCESS_4 ((uint8_t) 4) //!< Read or write 4 bytes. +#define SHA204_ZONE_ACCESS_32 ((uint8_t) 32) //!< Read or write 32 bytes. +#define SHA204_ADDRESS_MASK_CONFIG ( 0x001F) //!< Address bits 5 to 7 are 0 for Configuration zone. +#define SHA204_ADDRESS_MASK_OTP ( 0x000F) //!< Address bits 4 to 7 are 0 for OTP zone. +#define SHA204_ADDRESS_MASK ( 0x007F) //!< Address bit 7 to 15 are always 0. + +// GenDig command definitions +#define GENDIG_ZONE_IDX SHA204_PARAM1_IDX //!< GenDig command index for zone +#define GENDIG_KEYID_IDX SHA204_PARAM2_IDX //!< GenDig command index for key id +#define GENDIG_DATA_IDX SHA204_DATA_IDX //!< GenDig command index for optional data +#define GENDIG_COUNT SHA204_CMD_SIZE_MIN //!< GenDig command packet size without "other data" +#define GENDIG_COUNT_DATA (11) //!< GenDig command packet size with "other data" +#define GENDIG_OTHER_DATA_SIZE (4) //!< GenDig size of "other data" +#define GENDIG_ZONE_CONFIG ((uint8_t) 0) //!< GenDig zone id config +#define GENDIG_ZONE_OTP ((uint8_t) 1) //!< GenDig zone id OTP +#define GENDIG_ZONE_DATA ((uint8_t) 2) //!< GenDig zone id data + +// HMAC command definitions +#define HMAC_MODE_IDX SHA204_PARAM1_IDX //!< HMAC command index for mode +#define HMAC_KEYID_IDX SHA204_PARAM2_IDX //!< HMAC command index for key id +#define HMAC_COUNT SHA204_CMD_SIZE_MIN //!< HMAC command packet size +#define HMAC_MODE_MASK ((uint8_t) 0x74) //!< HMAC mode bits 0, 1, 3, and 7 are 0. +#define HMAC_MODE_SOURCE_FLAG_MATCH ((uint8_t) 0x04) //!< HMAC mode bit 2: match TempKey.SourceFlag + +// Nonce command definitions +#define NONCE_MODE_IDX SHA204_PARAM1_IDX //!< Nonce command index for mode +#define NONCE_PARAM2_IDX SHA204_PARAM2_IDX //!< Nonce command index for 2. parameter +#define NONCE_INPUT_IDX SHA204_DATA_IDX //!< Nonce command index for input data +#define NONCE_COUNT_SHORT (27) //!< Nonce command packet size for 20 bytes of data +#define NONCE_COUNT_LONG (39) //!< Nonce command packet size for 32 bytes of data +#define NONCE_MODE_MASK ((uint8_t) 3) //!< Nonce mode bits 2 to 7 are 0. +#define NONCE_MODE_SEED_UPDATE ((uint8_t) 0x00) //!< Nonce mode: update seed +#define NONCE_MODE_NO_SEED_UPDATE ((uint8_t) 0x01) //!< Nonce mode: do not update seed +#define NONCE_MODE_INVALID ((uint8_t) 0x02) //!< Nonce mode 2 is invalid. +#define NONCE_MODE_PASSTHROUGH ((uint8_t) 0x03) //!< Nonce mode: pass-through +#define NONCE_NUMIN_SIZE (20) //!< Nonce data length +#define NONCE_NUMIN_SIZE_PASSTHROUGH (32) //!< Nonce data length in pass-through mode (mode = 3) + +// Random command definitions +#define RANDOM_MODE_IDX SHA204_PARAM1_IDX //!< Random command index for mode +#define RANDOM_PARAM2_IDX SHA204_PARAM2_IDX //!< Random command index for 2. parameter +#define RANDOM_COUNT SHA204_CMD_SIZE_MIN //!< Random command packet size +#define RANDOM_SEED_UPDATE ((uint8_t) 0x00) //!< Random mode for automatic seed update +#define RANDOM_NO_SEED_UPDATE ((uint8_t) 0x01) //!< Random mode for no seed update + +// Write command definitions +#define WRITE_ZONE_IDX SHA204_PARAM1_IDX //!< Write command index for zone +#define WRITE_ADDR_IDX SHA204_PARAM2_IDX //!< Write command index for address +#define WRITE_VALUE_IDX SHA204_DATA_IDX //!< Write command index for data +#define WRITE_MAC_VS_IDX ( 9) //!< Write command index for MAC following short data +#define WRITE_MAC_VL_IDX (37) //!< Write command index for MAC following long data +#define WRITE_COUNT_SHORT (11) //!< Write command packet size with short data and no MAC +#define WRITE_COUNT_LONG (39) //!< Write command packet size with long data and no MAC +#define WRITE_COUNT_SHORT_MAC (43) //!< Write command packet size with short data and MAC +#define WRITE_COUNT_LONG_MAC (71) //!< Write command packet size with long data and MAC +#define WRITE_MAC_SIZE (32) //!< Write MAC size +#define WRITE_ZONE_MASK ((uint8_t) 0xC3) //!< Write zone bits 2 to 5 are 0. +#define WRITE_ZONE_WITH_MAC ((uint8_t) 0x40) //!< Write zone bit 6: write encrypted with MAC + +// Response size definitions +#define GENDIG_RSP_SIZE SHA204_RSP_SIZE_MIN //!< response size of GenDig command +#define HMAC_RSP_SIZE SHA204_RSP_SIZE_MAX //!< response size of HMAC command +#define NONCE_RSP_SIZE_SHORT SHA204_RSP_SIZE_MIN //!< response size of Nonce command with mode[0:1] = 3 +#define NONCE_RSP_SIZE_LONG SHA204_RSP_SIZE_MAX //!< response size of Nonce command +#define RANDOM_RSP_SIZE SHA204_RSP_SIZE_MAX //!< response size of Random command +#define WRITE_RSP_SIZE SHA204_RSP_SIZE_MIN //!< response size of Write command + +// command timing definitions for minimum execution times (ms) +#define GENDIG_DELAY ((uint8_t) (11.0 * CPU_CLOCK_DEVIATION_NEGATIVE - 0.5)) +#define HMAC_DELAY ((uint8_t) (27.0 * CPU_CLOCK_DEVIATION_NEGATIVE - 0.5)) +#define NONCE_DELAY ((uint8_t) (22.0 * CPU_CLOCK_DEVIATION_NEGATIVE - 0.5)) +#define RANDOM_DELAY ((uint8_t) (11.0 * CPU_CLOCK_DEVIATION_NEGATIVE - 0.5)) +#define WRITE_DELAY ((uint8_t) ( 4.0 * CPU_CLOCK_DEVIATION_NEGATIVE - 0.5)) + +// command timing definitions for maximum execution times (ms) +#define GENDIG_EXEC_MAX ((uint8_t) (43.0 * CPU_CLOCK_DEVIATION_POSITIVE + 0.5)) +#define HMAC_EXEC_MAX ((uint8_t) (69.0 * CPU_CLOCK_DEVIATION_POSITIVE + 0.5)) +#define NONCE_EXEC_MAX ((uint8_t) (60.0 * CPU_CLOCK_DEVIATION_POSITIVE + 0.5)) +#define RANDOM_EXEC_MAX ((uint8_t) (50.0 * CPU_CLOCK_DEVIATION_POSITIVE + 0.5)) +#define WRITE_EXEC_MAX ((uint8_t) (42.0 * CPU_CLOCK_DEVIATION_POSITIVE + 0.5)) + +/* from sha204_config.h */ + +#define CPU_CLOCK_DEVIATION_POSITIVE (1.01) +#define CPU_CLOCK_DEVIATION_NEGATIVE (0.99) +#define SHA204_RETRY_COUNT (1) +#define SWI_RECEIVE_TIME_OUT ((uint16_t) 163) //! #START_PULSE_TIME_OUT in us instead of loop counts +#define SWI_US_PER_BYTE ((uint16_t) 313) //! It takes 312.5 us to send a byte (9 single-wire bits / 230400 Baud * 8 flag bits). +#define SHA204_SYNC_TIMEOUT ((uint8_t) 85)//! delay before sending a transmit flag in the synchronization routine +#define SHA204_RESPONSE_TIMEOUT ((uint16_t) SWI_RECEIVE_TIME_OUT + SWI_US_PER_BYTE) //! SWI response timeout is the sum of receive timeout and the time it takes to send the TX flag. + +/* from sha204_comm.h */ + +#define SHA204_COMMAND_EXEC_MAX ((uint8_t) (69.0 * CPU_CLOCK_DEVIATION_POSITIVE + 0.5)) //! maximum command delay +#define SHA204_CMD_SIZE_MIN ((uint8_t) 7) //! minimum number of bytes in command (from count byte to second CRC byte) +#define SHA204_CMD_SIZE_MAX ((uint8_t) NONCE_COUNT_LONG) //! maximum size of command packet (Nonce) +#define SHA204_CRC_SIZE ((uint8_t) 2) //! number of CRC bytes +#define SHA204_BUFFER_POS_STATUS (1) //! buffer index of status byte in status response +#define SHA204_BUFFER_POS_DATA (1) //! buffer index of first data byte in data response +#define SHA204_STATUS_BYTE_WAKEUP ((uint8_t) 0x11) //! command parse error +#define SHA204_STATUS_BYTE_PARSE ((uint8_t) 0x03) //! command parse error +#define SHA204_STATUS_BYTE_EXEC ((uint8_t) 0x0F) //! command execution error +#define SHA204_STATUS_BYTE_COMM ((uint8_t) 0xFF) //! communication error + +class atsha204Class +{ +private: + uint8_t device_pin; + volatile uint8_t *device_port_DDR, *device_port_OUT, *device_port_IN; + void sha204c_calculate_crc(uint8_t length, uint8_t *data, uint8_t *crc); + uint8_t sha204c_check_crc(uint8_t *response); + void swi_set_signal_pin(uint8_t is_high); + uint8_t swi_receive_bytes(uint8_t count, uint8_t *buffer); + uint8_t swi_send_bytes(uint8_t count, uint8_t *buffer); + uint8_t swi_send_byte(uint8_t value); + uint8_t sha204p_receive_response(uint8_t size, uint8_t *response); +public: + atsha204Class(uint8_t pin); // Constructor + uint8_t sha204c_wakeup(uint8_t *response); + uint8_t sha204c_sleep(); + uint8_t 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 sha204c_resync(uint8_t size, uint8_t *response); + uint8_t sha204m_execute(uint8_t op_code, uint8_t param1, uint16_t param2, + uint8_t datalen1, uint8_t *data1, uint8_t tx_size, uint8_t *tx_buffer, uint8_t rx_size, uint8_t *rx_buffer); +}; + +#endif