6.4 Application Key File Format

The application.yaml file must contain application keys in hexadecimal format as follows:

chip_type: application
image_type: secure
security:
  signature:
    type: CMAC_AES
    key_data: data: 0000000000000000000000000000000000000000000000000000000000000000
  cipher: 
    type: AESs
    key_data: data: 0000000000000000000000000000000000000000000000000000000000000000
    iv_data: data: 00000000000000000000000000000000
specifics:
    header: True

The length of the AES Cipher key and AES CMAC key can be:

• 128 bits (16 bytes, 32 hexadecimal digits)
• 192 bits (24 bytes, 48 hexadecimal digits)
• 256 bits (32 bytes, 64 hexadecimal digits)