yuming
78 lines
2.1 KiB
Python
78 lines
2.1 KiB
Python
"""Crypto utils"""
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import base64
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from Crypto.Cipher import AES
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class AesBase64(object):
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"""for AES encryption"""
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def __init__(self, key: str, iv: str):
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self.key = key.encode("utf-8")
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self.iv = iv.encode("utf-8")
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self.mode = AES.MODE_CBC
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def encrypt(self, content):
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"""
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Encrypts the given content using the AES encryption algorithm.
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Parameters:
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content (str): The content to be encrypted.
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Returns:
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str: The encrypted content encoded in base64.
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"""
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cipher = AES.new(self.key, AES.MODE_CBC, self.iv)
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content_padding = self.pkcs7padding(content)
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encrypt_bytes = cipher.encrypt(content_padding.encode("utf-8"))
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return base64.b64encode(encrypt_bytes)
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def decrypt(self, content):
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"""
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Decrypts the given content using AES encryption
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with Cipher Block Chaining (CBC) mode.
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Parameters:
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content (str): The content to be decrypted.
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Returns:
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str: The decrypted text.
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"""
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cipher = AES.new(self.key, AES.MODE_CBC, self.iv)
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content = base64.b64decode(content)
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text = cipher.decrypt(content).decode("utf-8")
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return self.pkcs7unpadding(text)
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def pkcs7unpadding(self, text):
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"""
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Removes the PKCS#7 padding from the given text.
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Parameters:
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text (str): The text to remove padding from.
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Returns:
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str: The text without PKCS#7 padding.
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"""
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length = len(text)
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unpadding = ord(text[length - 1])
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return text[0 : length - unpadding]
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def pkcs7padding(self, text):
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"""
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Adds PKCS7 padding to the given text.
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Args:
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text (str): The text to be padded.
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Returns:
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str: The padded text.
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"""
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bs = 16
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length = len(text)
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bytes_length = len(text.encode("utf-8"))
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padding_size = length if (bytes_length == length) else bytes_length
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padding = bs - padding_size % bs
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padding_text = chr(padding) * padding
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return text + padding_text
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