AES CCM encryption/decryption examples

[Lucas]

Hello,

Are there examples of AES CCM encryption/decription?

Is there a recommended procedure for generating nounces?

Are there recommended procedures for using CCM?

Thank you.

Update: I forgot to mention I am using a nrf52832.

[ovrebekk]

Hi Lucas

I made an example and made it available on Github:
github.com/.../nrf52-esb-ccm-example

Please have a look at it and let me know if it can be of any help. If you have any feedback on the code I will make sure to take it into consideration :)

Best regards
Torbjørn

[Macro]

Hi, I have a few questions appeared at same: CCM data field is defined in example as: typedef struct { uint8_t key[CCM_KEY_SIZE]; uint64_t counter; uint8_t _padding[8 - CCM_COUNTER_SIZE]; uint8_t iv[CCM_IV_SIZE];
}ccm_data_t; In NRF52832 product specification address offset of 24 octet mentions direction bit without further explanation and generally after 8 (effective 5) byte counter field is only 1 byte before nonce IV location. In example there is 3 byte _padding instead. BR Macro