101 lines
3.4 KiB
Python
101 lines
3.4 KiB
Python
import base64
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import time
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from Crypto.PublicKey import RSA
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from Crypto.Signature import pkcs1_15
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from Crypto.Hash import SHA256
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from Crypto.Cipher import PKCS1_OAEP
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class Cryptography:
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@staticmethod
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def generate_key_pair():
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# Generate RSA key pair
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key = RSA.generate(2048)
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private_key = key.export_key(format='DER')
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public_key = key.publickey().export_key(format='DER')
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# Return keys in Base64 encoding
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return {
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'privateKey': base64.b64encode(private_key).decode('utf-8'),
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'publicKey': base64.b64encode(public_key).decode('utf-8')
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}
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@staticmethod
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def sign_content(content, private_key_base64):
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# Decode the Base64 private key
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private_key = RSA.import_key(base64.b64decode(private_key_base64))
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# Hash the content using SHA256
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h = SHA256.new(content.encode('utf-8'))
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# Sign the hash
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signature = pkcs1_15.new(private_key).sign(h)
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# Return the signature in Base64 encoding
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return base64.b64encode(signature).decode('utf-8')
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@staticmethod
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def verify_content(content, signature_base64, public_key_base64):
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# Decode the Base64 public key and signature
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public_key = RSA.import_key(base64.b64decode(public_key_base64))
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signature = base64.b64decode(signature_base64)
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# Hash the content
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h = SHA256.new(content.encode('utf-8'))
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try:
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# Verify the signature
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pkcs1_15.new(public_key).verify(h, signature)
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return True
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except (ValueError, TypeError):
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return False
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@staticmethod
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def temporary_sign_content(content, private_key_base64, frames=1):
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# Calculate the current time block
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time_block = int(time.time() // 60)
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# Append the time block to the content
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content_with_time = f"{content}|{time_block}"
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# Sign the content with the time block
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return Cryptography.sign_content(content_with_time, private_key_base64)
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@staticmethod
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def verify_temporary_signature(content, signature_base64, public_key_base64, frames=1):
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# Calculate the current time block
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time_block = int(time.time() // 60)
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# Check for each time block within the frame range
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for i in range(frames):
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content_with_time = f"{content}|{time_block - i}"
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if Cryptography.verify_content(content_with_time, signature_base64, public_key_base64):
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return True
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return False
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@staticmethod
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def encrypt_content(content, public_key_base64):
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# Decode the Base64 public key
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public_key = RSA.import_key(base64.b64decode(public_key_base64))
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# Encrypt the content using RSA-OAEP
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cipher = PKCS1_OAEP.new(public_key)
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ciphertext = cipher.encrypt(content.encode('utf-8'))
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# Return the ciphertext in Base64 encoding
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return base64.b64encode(ciphertext).decode('utf-8')
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@staticmethod
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def decrypt_content(ciphertext_base64, private_key_base64):
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# Decode the Base64 private key and ciphertext
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private_key = RSA.import_key(base64.b64decode(private_key_base64))
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ciphertext = base64.b64decode(ciphertext_base64)
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# Decrypt the content using RSA-OAEP
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cipher = PKCS1_OAEP.new(private_key)
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plaintext = cipher.decrypt(ciphertext)
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# Return the decrypted content
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return plaintext.decode('utf-8')
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