37 lines
1.5 KiB
Python
37 lines
1.5 KiB
Python
from cryptography.hazmat.primitives import hashes
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from cryptography.hazmat.primitives.asymmetric import ec
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from cryptography.hazmat.primitives.kdf.hkdf import HKDF
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from cryptography.hazmat.primitives.serialization import PublicFormat, Encoding, load_pem_public_key
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def generate_keys():
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private_key = ec.generate_private_key(
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ec.SECP384R1()
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)
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public_key = private_key.public_key()
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return public_key, private_key
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def generate_shared_key(private_key:ec.EllipticCurvePrivateKey, public_key:ec.EllipticCurvePublicKey):
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shared_key = private_key.exchange(ec.ECDH(), public_key)
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return shared_key
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def generate_derived_key(shared_key:bytes):
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derived_key = HKDF(
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algorithm=hashes.SHA256(),
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length=32,
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salt=None,
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info=None,
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).derive(shared_key)
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return derived_key
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def public_key_to_str(public_key:ec.EllipticCurvePublicKey, remove_header_and_footer=False):
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public_key_str = public_key.public_bytes(Encoding.PEM, PublicFormat.SubjectPublicKeyInfo).decode()
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if(remove_header_and_footer):
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public_key_str = public_key_str.replace('-----BEGIN PUBLIC KEY-----\n','')
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public_key_str = public_key_str.replace('\n-----END PUBLIC KEY-----\n','')
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return public_key_str
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def load_public_key_str(public_key_str:str, removed_header_and_footer=False):
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if(removed_header_and_footer):
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public_key_str = f'-----BEGIN PUBLIC KEY-----\n{public_key_str}\n-----END PUBLIC KEY-----\n'
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return load_pem_public_key(public_key_str.encode())
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