Pair a key

Every command is signed with a key the car already trusts. Pairing is a one-time whitelist on VCSEC.

Create or load the key

TeslaBLE::Authenticator authenticator;

authenticator.CreatePrivateKey();

Or load a PEM you already stored:

const unsigned char pem[] = "-----BEGIN EC PRIVATE KEY-----\n...\n-----END EC PRIVATE KEY-----";
authenticator.LoadPrivateKey(pem, sizeof pem);

Export the PEM and load it on the next boot:

unsigned char pem_out[256];
size_t pem_size = 0;
authenticator.GetPrivateKey(pem_out, sizeof pem_out, &pem_size);

Authenticator::LoadPrivateKey takes the PEM bytes and size.

Whitelist

unsigned char buffer[256];
size_t size = 0;
authenticator.BuildKeyWhitelistMessage(
    Keys_Role_ROLE_OWNER,
    VCSEC_KeyFormFactor_KEY_FORM_FACTOR_ANDROID_DEVICE,
    buffer,
    &size);

ROLE_GUEST is valid. Form factor is an argument. Send buffer over the VCSEC BLE characteristic (see BLE framing).

The car replies with an operation status:

Status	Meaning
OPERATIONSTATUS_OK	Key is on the whitelist
OPERATIONSTATUS_WAIT	Present the NFC card, then retry
OPERATIONSTATUS_ERROR	Rejected

After OPERATIONSTATUS_OK, request session info. UpdateSessionInfo decodes the VCSEC status before it stores epoch and counter.