SparkFun Cryptographic Co-Processor Breakout - ATECC608A, unable to verify signatures computer side

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1

Hello,

using the ATECC608A & the library suggested I was able to complete the tutorial.

However one thing is bugging me: I am completely unable to verify the signatures computer side: I have the key, the data and the message as per the examples but I cannot find a way to verify such signatures computer-side, ideally with python.

Help would be very much appreciated, ideally in the form of a well-commented python script.

Here are my keys/message/signature:

uint8_t publicKey[64] = {
0x40, 0x11, 0x4E, 0xBB, 0x81, 0x4E, 0x71, 0xA6, 0xBE, 0x63, 0x18, 0x30, 0x9D, 0x14, 0x1D, 0xD8,
0xEB, 0x4B, 0xFD, 0xBE, 0x93, 0x7B, 0xD0, 0x09, 0x05, 0x59, 0xFB, 0xD7, 0x70, 0x23, 0xDA, 0x28,
0x4E, 0xBF, 0x38, 0x19, 0x04, 0x8E, 0x5A, 0x4C, 0x21, 0xAC, 0xC9, 0x34, 0x05, 0x5B, 0x8E, 0xF2,
0xCD, 0xF4, 0xEE, 0x71, 0x86, 0xF0, 0x70, 0x49, 0x51, 0x6D, 0x5E, 0xEA, 0x2A, 0xE0, 0x34, 0x07
};

uint8_t message[32] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F
};

uint8_t signature[64] = {
0xE0, 0x33, 0x96, 0xC3, 0xB0, 0x82, 0x74, 0xFD, 0xED, 0x0C, 0xC7, 0xEE, 0x55, 0xEF, 0xF8, 0x70,
0x84, 0x71, 0xB4, 0x3A, 0x9D, 0xFD, 0x76, 0x9D, 0x6C, 0x22, 0x7E, 0xE4, 0x5A, 0xD2, 0x0B, 0x5C,
0xF7, 0x8A, 0x2F, 0x6C, 0x22, 0x9C, 0x30, 0xE2, 0x06, 0x9E, 0x3D, 0x69, 0x39, 0xE5, 0x34, 0x63,
0xE8, 0x17, 0x79, 0xB3, 0xF4, 0x8F, 0x6C, 0x07, 0x5B, 0x6A, 0xCC, 0xE4, 0x3A, 0x6C, 0xC4, 0x65
};

This is driving me crazy! :smiley:

2

This is a SparkX product, which means we only guarantee the hardware for such…but you might find benefit from reading through the 508a hookup guide https://learn.sparkfun.com/tutorials/cr … no-library , which references examples https://github.com/sparkfun/SparkFun_AT … r/examples that you should be able to change to suit your needs …thought these are arduino examples, python can interpret them

Hope this helps!

3

Edit: found example code on Microchip’s github. It’s in various locations but searching “ATECC*08” leads good results.

Leaving it here for future reference :slight_smile:

4

I am unable to generate a signature using the createSignature(), using the SparkFun_ATECCX08a_Arduino_Library - atecc.createSignature(message) returns false. Debugging shows an error in the loadTempKey function.

I have successfully configured the device to default settings per library Example 1, but am stuck on Example 2 because of the signature failure.

Is there some part of the default configuration / locking that is interfering with the loadTempKey or createSignature commands?

Has anyone else had this problem and solved it?