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Ucryptolib Module API Manual

Overview

The Ucryptolib library provides the following encryption and decryption functionalities: AES-ECB, AES-CBC, AES-CTR.

For related information, please refer to MicroPython’s cryptolib official documentation.

API Introduction

The Ucryptolib library provides the aes class, which implements encryption (encrypt) and decryption (decrypt) operations.

Class aes

Constructor

Description

Initializes the encryption algorithm object, suitable for encryption/decryption.

Note: After initialization, the encryption algorithm object can only be used for either encryption or decryption. Running a decryption operation after an encryption operation, or vice versa, is not supported.

Syntax

ucryptolib.aes(key, mode[, IV])

Parameters

• key : The encryption/decryption key (bytes-like object).

• mode :

  • 1 for Electronic Codebook (ECB).

  • 2 for Cipher Block Chaining (CBC).

  • 6 for Counter mode (CTR).

• IV : Initialization vector for CBC mode. For counter mode, IV is the initial value of the counter.

encrypt Method

Description

Encrypts in_buf. If out_buf is not given, the result is returned as a newly allocated bytes object. Otherwise, the result is written into the mutable buffer out_buf. in_buf and out_buf can also refer to the same mutable buffer, in which case the data is encrypted in place.

Syntax

enc = aes.encrypt(in_buf[, out_buf])

decrypt Method

Description

Similar to encrypt(), but used for decryption.

Syntax

dec = aes.decrypt(in_buf[, out_buf])

Example

from ucryptolib import aes
# ECB mode
crypto = aes(b"1234" * 4, 1)
enc = crypto.encrypt(bytes(range(32)))
print(enc)
crypto = aes(b"1234" * 4, 1)
print(crypto.decrypt(enc))