I'd like to use this library with the M5Stack Core2 IoT EduKit but there is a compile error on an ESP32 and the I2C address of the ATECC608 is different.

The compile error fix is from #25

For the I2C address I can see that with the existing code you can create your own instance with a custom I2C address, but then all the provided utilities don't work so you'd need you own of those too, so this new begin(i2cAddr) function makes it all work more seemlessly.

What do you think?

Addressing issue #42

Adding nonce functionality

• Exposing challenge private function which does nonce

Adding HMAC functionality

• Did not implement for 508
• beginHMAC: SHA opcode, uses HMAC begin mode.
• updateHMAC: implements while loop for processing data of different lengths.
• endHMAC: in 608 does not differ from endSHA256.

Adding HMAC and nonce example

• Simple example to do an HMAC 256 operation using nonce and HMAC (0xFFFF is keySlot for TempKey)

Hi,

I have a rather strange behaviour: as soon as it communicates with the ECC508 chip, the rest of the I2C devices stops.

It is running on an Arduino MKR WiFI 1010. I used several I2C components (a 4x20 LCD device, a couple of PCF8574 chip, a PN532 NFC reader and a EEPROM.

Many thanks in advance for your help.

Hi. There's a bug in ASN1Utils.cpp, in functions that deal with the creation of the signatures (signatureLength, appendSignature) where a value consisting of only zeros can cause problems.

while (*r == 0x00 && rLength) { should be changed to: while (rLength && *r == 0x00) {

and

if (*r & 0x80) { should be changed to: if (rLength && *r & 0x80) {

Similar changes should be granted to s and sLength.

Of course the probability of an all zeros signature is remote in a real-case scenario, but not in tests.

Wire.cpp requestFrom do not understand the bool. It throws the following error: ECCX08.cpp:724:80: error: call of overloaded 'requestFrom(uint8_t, size_t, bool)' is ambiguous

A user in the forums had issues which were tracked back to this library's begin. When using a motor shield via a MKR to UNO adapter, pins 11 and 12 were interfering with the correct functioning of the TWI. begin() could use a timeout and return failure. This has repercussions on ArduinoIoTCloud. Forum post here https://forum.arduino.cc/index.php?topic=606191.new#new

The example script ECCX08RandomNumber.ino did not work correctly. With a logic analyzer on the I2C I can see, that the random number ist transmitted from ATECC508A, but 20 times. It seems, that the buffersize of the wire.h lib can only receive 32 byte and the ATECC sends 32 + 3 byte (length and CRC) byte. This error appears in int ECCX08Class::receiveResponse(void* response, size_t length) and leads to a CRC-error.

On compiling the example file in Platformio for Arduino UNO, I get an error:

C:\Users\user.platformio\lib\ArduinoECCX08_ID5570\src\ECCX08.cpp:622:80: error: call of overloaded 'requestFrom(uint8_t, size_t, bool)' is ambiguous

It seems, that changing the Line 622 of ECCX08.cpp to while (_wire->requestFrom((uint8_t)_address, (size_t)responseSize) != responseSize && retries--); solves the problem.

This avoids having a global SHA1 symbol so another library can define it.

Note: the SHA1 code is needed for the self signed certificate sketch because Azure IoT Hub needs a SHA1.

According to the datasheet, the ECC508 can do HMAC hashing but I don't see it implemented in this library. Is it possible to do HMAC-SHA256 hashing with this library?

Fixed the minimum length for INTEGER types (>=1) Fixed encoding length for negative types Fixed mix of rLength with sLength in appendSignature() Fixed length returned in appendSerialNumber() and appendSignature() Removed zero-length checks where length is guaranteed to be greater than zero.

Hi, i'm think that Inside the wakeup() method this sentence should be: "_wire->beginTransmission(_address);" instead of " _wire->beginTransmission(0x00);" isn't it?

I'm using this on an ESP32 device (M5Stack Core2 for AWS). The error message isn't very specific. Here's what I get trying to use slot 0 and storage slot 8:

Please enter the issue year of the certificate? (2000 - 2031) [2022]:
Please enter the issue month of the certificate? (1 - 12) [1]:
Please enter the issue day of the certificate? (1 - 31) [1]:
Please enter the issue hour of the certificate? (0 - 23) [0]:
Please enter how many years the certificate is valid for? (1 - 31) [1]:
What slot would you like to use for the private key? (0 - 4) [2]: 0
What slot would you like to use for storage? (8 - 15) [8]: 8
Would you like to generate a new private key? (Y/n) [Y]: Y

Error starting self signed cert generation!

I was able to eventually get it working with Slot 2, Slot 8 but the "generate new private key" option never worked for me. I also found that some slot combinations outputs the SHA but not the public cert.

It's been a tough one to troubleshoot because I can only seem to get a working cert about one out of every ten tries.

This adds a function to perform an ECDH key exchange and adds the standardized AES-GCM encryption/decryption algorithms which use the exchanged key to perform authenticated encryption/decryption.

Hi,

I'm using the MKR1000 board, and trying to generate a CSR with the sketch example ECCX08CSR the code stop at this condition:

if (!ECCX08CSR.begin(slot.toInt(), generateNewKey.startsWith("Y")) {
  Serial.println("Error starting CSR generation!");
  while (1);"

I locked the chip and get the SerialNumber when starting, it seems to work properly until the CSR genearation. i tried to bypass the condition, the CSR is empty. How can i troubleshoot this ? Thanks for help!

Team, we are trying to generate self signed certificate using ATECC608A chip. Our environment is Arduino M0 and ATECC608A chip is connected through I2C line and chip is recognized.

When we try to generate self signed certificate, we get the error, "Error starting self signed cert generation!" (beginStorage() function fails). When we debugged further, it fails at crc16() function in receiveResponse() in ECCX08.cpp file.

Any ideas on how to resolve this issue?

Best regards Malli