SpringCore Direct ATCRYPTO class

The ATCRYPTO class conveys direct commands to a Atmel/MicroChip ATECC608A or ATECC132A Secure Element, if the device has either.

Most of the instructions in this class are disabled when the device goes out of factory thanks to the "Lock ATCRYPTO" flag in the Fuses.

CLA value

The ATCRYPTO class uses CLA=59.

Message format

SpringCore Direct over USB, SpringCore Direct over BLE

The commands and the responses use the same format.

Field Length Description / remark
Header 4 or 6 bytes CLA = 59, LEN = length of Data
INS / STA 1 byte Command: opcode of the INStruction
Response: STAtus
Data 0 or more bytes Command data
Response data

Encapsulation in CCID Escape / SCardControl

Commands

Field Length Description / remark
CLA 1 byte 59
INS 1 byte opcode of the INStruction
Data 0 or more bytes Command data

Note

The length of the Command is not transmitted, as it can be deduced from the CCID header.

Responses

Item Length Description / remark
STA 1 byte STAtus
Data 0 or more bytes Response data

Note

The length of the Response is not transmitted, as it can be deduced from the CCID header.

The CLA byte is not transmitted.

List of INStructions

The INS opcodes are defined below:

INS Name Description Remark
00 INIT Initialize the ATECC or ATAES Factory only
01 BLANK Erase all keys in the ATECC or ATAES Factory only
10 SET KEY USER Set the HostCommUserKey Factory only, ATAES only
11 SET KEY ADMIN Set the HostCommAdminKey Factory only, ATAES only
41 SET_PRIVATE_KEY Write an ECC P-256 private key into the SE ATECC only
42 GENERATE_PRIVATE_KEY Generate an ECC P-256 private key inside the SE ATECC only
43 GET_PUBLIC KEY Read the public key associated to a private key ATECC only
46 SIGN Compute an ECC signature ATECC only
47 HASH_AND SIGN Compute an ECC signature ATECC only
48 ECDH Run the Diffie-Hellman agreement ATECC only
4E GET CSR Get a certificate signing request (CSR) for the specified key with its default subject ATECC only
4F GET CSR EX Get a certificate signing request (CSR) for the specified key with an arbitrary subject ATECC only

List of STAtus

The STA values are defines below:

STA Name Description
00 MI_OK Success