AES-CCM support and example

[thalesfragoso]

Example Output

02:22:23.976 Starting Encryption of 251 bytes
02:22:23.976 Encryption Took: 178 us
02:22:23.976
02:22:23.976 Starting Decryption of 255 bytes
02:22:23.976 Decryption Took: 1118 us
02:22:23.976
02:22:23.976
02:22:23.976 Starting Encryption of 128 bytes
02:22:23.976 Encryption Took: 119 us
02:22:23.976
02:22:23.976 Starting Decryption of 132 bytes
02:22:23.976 Decryption Took: 608 us
02:22:23.976
02:22:23.976
02:22:23.976 Starting Encryption of 64 bytes
02:22:23.976 Encryption Took: 90 us
02:22:23.976
02:22:23.976 Starting Decryption of 68 bytes
02:22:23.976 Decryption Took: 341 us
02:22:23.976
02:22:23.976
02:22:23.976 Starting Encryption of 32 bytes
02:22:23.976 Encryption Took: 75 us
02:22:23.976
02:22:23.976 Starting Decryption of 36 bytes
02:22:23.976 Decryption Took: 208 us
02:22:23.976
02:22:23.976
02:22:23.976 Starting Encryption of 16 bytes
02:22:23.976 Encryption Took: 33 us
02:22:23.976
02:22:23.976 Starting Decryption of 20 bytes
02:22:23.976 Decryption Took: 109 us
02:22:23.976
02:22:23.976
02:22:23.976 Done

It seems that the peripheral holds itself during decryption, because it was made to operate on-the-fly with the radio, so it can't decrypt faster than the radio receives data.

[thalesfragoso]

Hmm, it seems that the nRF51 is only capable of encrypting payloads with lengths up to 27 bytes, that's unfortunate, I will try to fix this problem tomorrow.

[jonas-schievink]

Nice work!

[thalesfragoso]

Thanks for the suggestions, updated.