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 official cryptolib documentation.

API Introduction

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

Class aes

Constructor

Description

Initialize the encryption algorithm object, which is suitable for encryption/decryption.

Note: After initialization, the encryption algorithm object can only be used for 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 : An encryption/decryption key (bytes-like).

• mode :

  • 1 for Electronic Code Book (ECB) mode.

  • 2 for Cipher Block Chaining (CBC) mode.

  • 6 for Counter mode (CTR) mode.

• IV : an initialization vector for CBC mode.For Counter mode, IV is the initial value for the counter.

encrypt

Description

Encrypt in_buf. If no out_buf is given result is returned as a newly allocated bytes object. Otherwise, result is written into mutable buffer out_buf. in_buf and out_buf can also refer to the same mutable buffer, in which case data is encrypted in-place.

Syntax

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

decrypt

Description

Like encrypt(), but 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))