Support for AES-CCM (Counter with CBC-MAC)

[ahpohl]

Have you considered supporting AES-CCM mode?

It's used, for example, in Bluetooth Low Energy (BLE) applications to encrypt the payload in advertisement packets.

The code I am writing is for ESPHome and runs on ESP32 etc., so the implementation needs to be optimized for "small" µC like NodeMCUs and AVRs. This library looks ideal to me and is already supported by the Arduino IDE and PlatformIO. Additionally, it supports the other AES AEAD modes GCM and EAX, so the implementation of CCM would be trivial.

Here is a test vector for 128 bit AES-CCM I am struggling with:

static TestVector const testVectorCCM PROGMEM = {
    .name        = "AES-128 CCM BLE ADV",
    .key         = {0xE9, 0xEF, 0xAA, 0x68, 0x73, 0xF9, 0xF9, 0xC8,
                    0x7A, 0x5E, 0x75, 0xA5, 0xF8, 0x14, 0x80, 0x1C},
    .plaintext   = {0x04, 0x10, 0x02, 0xD3, 0x00},
    .ciphertext  = {0xDA, 0x61, 0x66, 0x77, 0xD5},
    .authdata    = {0x11},
    .iv          = {0x78, 0x16, 0x4E, 0x38, 0xC1, 0xA4, 0x5B, 0x05,
                    0x3D, 0x2E, 0x00, 0x00},
    .tag         = {0x92, 0x98, 0x23, 0x52},
    .authsize    = 1,
    .datasize    = 5,
    .tagsize     = 4,
    .ivsize      = 12
};

I already have the BLE decryption working "offline", but the current code uses Crypto++ as its AES library and is not portable to ESPHome.

Thank you very much for your help and support in advance.