SWCU192 November 2021 CC1312R7 , CC1352P7 , CC2652P7 , CC2652R7
The AES security module provides hardware-accelerated data encryption and decryption operations based on a binary key. The module supports a 256-bit key in hardware for encryption and decryption and uses symmetric algorithm, meaning that the encryption and decryption keys are identical. Encryption converts plain text data to an unintelligible form called cipher text. Decrypting cipher text converts previously encrypted data back into its original plain text form. The main features of the AES module are:
ECB, CBC, CTR, GCM, and CCM modes require reading and writing of data. CBC-MAC requires only reading of the data from an external source. The CCM mode of operation returns an authentication result. This result can either be read with a separate DMA operation, or read through the slave interface. For all modes, an option provides (part of) the data through the slave interface instead of using DMA. The AES engine is forced to use keys from the key-store module for its operations. A key is provided to the AES engine by triggering the key-store module to read an AES key from the key store memory, and to write it to the AES key registers. The AES engine automatically pads or masks misaligned last data blocks with zeroes for AES CBC-MAC, GCM, and CCM (including misaligned AAD data). For AES CTR mode, misaligned last data blocks are internally masked to support nonblock size input data.