LAUNCHXL-CC26X2R1: CC26x2R

Ming Sun

Part Number: LAUNCHXL-CC26X2R1
Other Parts Discussed in Thread: SIMPLELINK-CC13X2-26X2-SDK

Hi,

I have some questions about the "KEY SIZE" in Bluetooth Stack:

Bluetooth Erratum 11838 is the so-called "KNOB attack"? Is its cause as described in [BLE] V4.2 Vol2 Part H 4.1 ENCRYPTION KEY SIZE NEGOTIATION? Is this issue ONLY applicable for BR/EDR controller?

I found two definitions related to the key length in SDK: one is GAP_PARAM_SM_MIN_KEY_LEN/GAP_PARAM_SM_MAX_KEY_LEN, another one is GAPBOND_KEYSIZE. They look like the former is for the encryption key, the latter is for the LTK, is it right? What is the relationship of these two keys/definitions? Is the former one related to Bluetooth Erratum 11838? And is the latter generated by the former one?

Sorry to ask these messy questions, thank you for your patience.

Ming

over 3 years ago

0 Clément over 3 years ago

TI__Guru* 97640 points

Hi Ming,

Erratum 11838 does apply to Bluetooth LE too.

For CC26x2/CC13x2 devices, an update has been made in the BLE5 Stack version 2.01.02.00 released within theSIMPLELINK-CC13X2-26X2-SDK version 4_10_00_78 - in other words, all the SIMPLELINK-CC13X2-26X2-SDK with a version number equal or superior to 4_10_00_78 have implemented the erratum.

I recommend to review the application report "How to Certify Your Bluetooth Product" section §2.1.2.2 for additional details.

Best regards,

0 Ming Sun over 3 years ago in reply to Clément

Prodigy 30 points

Thanks for your reply, Clement.

Could you describe the purpose of these two parameters, GAP_PARAM_SM_MIN(MAX)_KEY_LEN and GAPBOND_KEYSIZE?

Ming

0 Clément over 3 years ago in reply to Ming Sun

TI__Guru* 97640 points

Hi,

GAP_PARAM_SM_MIN_KEY_LEN: Minimum Key Length required by the Security Manager

GAP_PARAM_SM_MAX_KEY_LEN: Maximum Key Length supported by the Security Manager

GAPBOND_KEYSIZE: Key size used for pairing

Regards,

0 Ming Sun over 3 years ago in reply to Clément

Prodigy 30 points

Thanks Clement,

Is GAP_PARAM_SM_MIN(MAX)_KEY_LEN related to [BLE] V4.2 Vol2 Part H 4.1 ENCRYPTION KEY SIZE NEGOTIATION?

Ming

0 Ming Sun over 3 years ago in reply to Ming Sun

Prodigy 30 points

Are they the limitation of GAPBOND_KEYSIZE?

+1 Clément over 3 years ago in reply to Ming Sun

TI__Guru* 97640 points

Hi,

The symbols GAP_PARAM_SM_MIN_KEY_LEN and GAP_PARAM_SM_MAX_KEY_LEN are related to the BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 3, Part H, §2.3.4.

GAPBOND_KEYSIZE should be in the range GAP_PARAM_SM_MIN_KEY_LEN GAP_PARAM_SM_MAX_KEY_LEN

Regards,

0 Ming Sun over 3 years ago in reply to Clément

Prodigy 30 points

Thanks Clement.

0 Clément over 3 years ago in reply to Ming Sun

TI__Guru* 97640 points

Anytime :)

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LAUNCHXL-CC26X2R1: CC26x2R