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https://github.com/aljazceru/python-nostr.git
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63 lines
2.4 KiB
Python
63 lines
2.4 KiB
Python
import os
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import base64
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from cffi import FFI
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from secp256k1 import PrivateKey, PublicKey
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from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
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from cryptography.hazmat.primitives import padding
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def generate_private_key() -> str:
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private_key = PrivateKey()
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public_key = private_key.pubkey.serialize().hex()
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while not public_key.startswith("02"):
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private_key = PrivateKey()
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public_key = private_key.pubkey.serialize().hex()
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return private_key.serialize()
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def get_public_key(secret: str) -> str:
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private_key = PrivateKey(bytes.fromhex(secret))
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public_key = private_key.pubkey.serialize().hex()
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return public_key[2:] # chop off sign byte
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def get_key_pair() -> tuple:
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private_key = PrivateKey()
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public_key = private_key.pubkey.serialize().hex()
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return (private_key.serialize(), public_key[2:])
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def compute_shared_secret(sender_private_key: str, receiver_public_key: str) -> str:
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public_key = PublicKey(bytes.fromhex("02" + receiver_public_key), True)
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return public_key.ecdh(bytes.fromhex(sender_private_key), copy_x).hex()
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def encrypt_message(content: str, shared_secret: str) -> str:
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iv = os.urandom(16)
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cipher = Cipher(algorithms.AES(bytes.fromhex(shared_secret)), modes.CBC(iv))
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padder = padding.PKCS7(128).padder()
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padded_data = padder.update(content.encode()) + padder.finalize()
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encryptor = cipher.encryptor()
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encrypted_message = encryptor.update(padded_data) + encryptor.finalize()
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return f"{base64.b64encode(encrypted_message).decode()}?iv={base64.b64encode(iv).decode()}"
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def decrypt_message(encoded_message: str, shared_secret: str) -> str:
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encoded_data = encoded_message.split('?iv=')
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encoded_content, encoded_iv = encoded_data[0], encoded_data[1]
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encrypted_content = base64.b64decode(encoded_content)
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iv = base64.b64decode(encoded_iv)
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cipher = Cipher(algorithms.AES(bytes.fromhex(shared_secret)), modes.CBC(iv))
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decryptor = cipher.decryptor()
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decrypted_message = decryptor.update(encrypted_content) + decryptor.finalize()
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unpadder = padding.PKCS7(128).unpadder()
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unpadded_data = unpadder.update(decrypted_message) + unpadder.finalize()
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return unpadded_data.decode()
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ffi = FFI()
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@ffi.callback("int (unsigned char *, const unsigned char *, const unsigned char *, void *)")
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def copy_x(output, x32, y32, data):
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ffi.memmove(output, x32, 32)
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return 1
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