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class AES - Advanced Encryption
Standard
AES (Advanced Encryption Standard) is a symmetric block cipher standardised by NIST. It
has a fixed data block size of 16 bytes. Its keys can be 128, 192, or 256 bits long.
AES is implemented using the ESP32 hardware module.
Quick Usage Example
from crypto import AES
import crypto
key = b'notsuchsecretkey' # 128 bit (16 bytes) key
iv = crypto.getrandbits( 128 ) # hardware generated random IV (never reuse it)
cipher = AES(key, AES.MODE_CFB, iv)
msg = iv + cipher.encrypt( b'Attack at dawn' )
# ... after properly sent the encrypted message somewhere ...
cipher = AES(key, AES.MODE_CFB, msg[: 16 ]) # on the decryption side
original = cipher.decrypt(msg[ 16 :])
print(original)
Constructors
class ucrypto.AES(key, mode, IV, * , counter, segment_size)
Create an AES object that will let you encrypt and decrypt messages.
The arguments are:
key
(byte string) is the secret key to use. It must be 16 (AES-128), 24 (AES-192), or
32 (AES-256) bytes long.
mode
is the chaining mode to use for encryption and decryption. Default is
AES.MODE_ECB.
IV
(byte string) initialisation vector. Should be 16 bytes long. It is ignored in modes
AES.MODE_ECB and AES.MODE_CRT.
counter
(byte string) used only for AES.MODE_CTR. Should be 16 bytes long. Should
not be reused.
5.2.3 AES
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