CryptoCell CC310 AES CCM* arbitrary Nonce

RE: CryptoCell CC310 AES CCM* arbitrary Nonce

chris-ho — Thu, 31 May 2018 12:38:13 GMT

the test vectors mentioned from Rune Holmgren are working but if you modify the nonce in those vectors, especially last byte CRYS_AESCCMStar returns error code 0x00F0150C which resolves in CRYS_AESCCM_ILLEGAL_PARAMETER_SIZE_ERROR

RE: CryptoCell CC310 AES CCM* arbitrary Nonce

Einar Thorsrud — Thu, 31 May 2018 12:31:20 GMT

Hi,

You are right that TSCH mode it not supported in the CryptoCell library in SDK 15 (0.9.9). We are looking into this so we may add support in a future SDK release.

RE: CryptoCell CC310 AES CCM* arbitrary Nonce

chris-ho — Thu, 31 May 2018 08:04:34 GMT

Hi Rune Holmgren

I figured out that the updated SDK v 15.0 seems only support the nonce format described in Chapter 9.3.2.1 of 802.15.4 -2015 (see Attachements) can you confirm that? Are there any plans to support the TSCH mode also with a future release? or is there a chance to get a patch or quick fix for that?

Best regards

Chris

RE: CryptoCell CC310 AES CCM* arbitrary Nonce

Rune Holmgren — Fri, 23 Mar 2018 16:41:56 GMT

Version 0.9.9 of the nrf_cc310 runtime library now supports all security levels described in the chapter 7.3.4.2 c data output in the IEEE Std 802.15.4™-2011 Low-Rate Wireless Personal Area Networks (LR-WPANs) standard. This version of the nrf_cc310 runtime library will be part of the upcoming nRF5 SDK 15.0.0 release.

Please refer to table in the spec: Table 56 c data for all security levels

Previously the nrf_cc310 runtime library only supported security level 4-7, but with version 0.9.9 of the nrf_cc310 runtime library security levels 0-3 is also supported. This includes the security levels None, MIC-32, MIC-64 and MIC-128.

Note that the nrf_cc310 runtime library and nrf_crypto_aead APIs still supports the deprecated security level 4 according to IEEE Std 802.15.4™-2015: IEEE Standard for Low-Rate Wireless Networks. This mode has been deprecated according to the standard

Please refer to Table 9-4 – c data for all security levels where mode 4 is removed

For reference (from the standard):

In previous version of the standard, security level 4 was a level which provided only data confidentiality but without data authenticity. This security level is deprecated and shall not be used in implementation compliant with this standard.

Security level 4 has NOT been explicitly removed from the nrf_cc310 runtime library or the nrf_crypto_aead APIs

Examples and verification

Examples of usage of the AES CCM* mode can be seen in the nrf_crypto_aead APIs which is added in the upcoming nRF5 SDK 15.0.0 release. These APIs use the nrf_cc310 runtime library as a portable cryptographic backend.

We have also provide added AES CCM* mode verification using standardized test vectors from IEEE P802.15-4/0537r2: Formal Specification of the CCM* Mode of Operation as well as custom vectors in an tailor made verification application that is using the nrf_crypto_aead APIs.