Function otPlatRadioSetMacKey 

pub unsafe extern "C" fn otPlatRadioSetMacKey(
    aInstance: *mut otInstance,
    aKeyIdMode: u8,
    aKeyIndex: u8,
    aPrevKey: *const otMacKeyMaterial,
    aCurrKey: *const otMacKeyMaterial,
    aNextKey: *const otMacKeyMaterial,
    aKeyType: otRadioKeyType,
)

Update MAC keys and key index.

Is used when radio provides OT_RADIO_CAPS_TRANSMIT_SEC capability.

Radio platform implementations MUST ignore the @p aKeyIdMode parameter entirely and treat the keys configured via this API as Key ID Mode 1 (standard Thread security).

This API was originally introduced with the @p aKeyIdMode parameter for potential future extensions, and it is retained in the function signature for backward compatibility. However, in practice, platform transmit security is only intended and used for Key ID Mode 1. Attempting to support or interpret other Key ID modes in the radio platform introduces complexity and ambiguity regarding how @p aKeyIdMode values are represented (e.g., bit-shifted as it appears in the IEEE 802.15.4 Security Control field vs. simple sequential mode values 0, 1, 2).

A call to this API replaces any previously set MAC keys.

The radio platform should reset the current security MAC frame counter tracked by the radio on this call. While this is highly recommended, the OpenThread stack, as a safeguard, will also reset the frame counter using the otPlatRadioSetMacFrameCounter() before calling this API.

@param[in] aInstance A pointer to an OpenThread instance. @param[in] aKeyIdMode The key ID mode (must be ignored by the radio platform). @param[in] aKeyIndex Current MAC key index. @param[in] aPrevKey A pointer to the previous MAC key. @param[in] aCurrKey A pointer to the current MAC key. @param[in] aNextKey A pointer to the next MAC key. @param[in] aKeyType Key Type used.