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Update d_01.py

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Bill Buchanan
2023-02-23 16:40:28 +00:00
committed by GitHub
parent b1f1a27cf0
commit c5c5436fd5
1 changed files with 36 additions and 12 deletions
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48
unit05_key_exchange/src/d_01.py
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@@ -1,18 +1,42 @@
from os import urandom
from eccsnacks.curve25519 import scalarmult, scalarmult_base
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives.kdf.hkdf import HKDF
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.backends import default_backend
import binascii
import sys
a = urandom(32)
a_pub = scalarmult_base(a)
b = urandom(32)
b_pub = scalarmult_base(b)
size=32 # 256 bit key
k_ab = scalarmult(a, b_pub)
k_ba = scalarmult(b, a_pub)
Bob_private_key = ec.generate_private_key(ec.SECP256K1(),default_backend())
Alice_private_key = ec.generate_private_key(ec.SECP256K1(),default_backend())
print "Bob public: ",binascii.hexlify(b_pub)
print "Alice public: ",binascii.hexlify(a_pub)
print "Bob shared: ",binascii.hexlify(k_ba)
print "Alice shared: ",binascii.hexlify(k_ab)
Bob_shared_key = Bob_private_key.exchange(ec.ECDH(), Alice_private_key.public_key())
Bob_derived_key = HKDF(algorithm=hashes.SHA256(),length=size,salt=None,info=b'',backend=default_backend()).derive(Bob_shared_key)
Alice_shared_key = Alice_private_key.exchange(ec.ECDH(), Bob_private_key.public_key())
Alice_derived_key = HKDF(algorithm=hashes.SHA256(),length=size,salt=None,info=b'',backend=default_backend()).derive(Alice_shared_key)
print ("Name of curve: ",Bob_private_key.public_key().curve.name)
print (f"Generated key size: {size} bytes ({size*8} bits)")
vals = Bob_private_key.private_numbers()
print (f"\nBob private key value: {vals.private_value}")
vals=Bob_private_key.public_key()
enc_point=binascii.b2a_hex(vals.public_bytes(encoding=serialization.Encoding.PEM,format=serialization.PublicFormat.SubjectPublicKeyInfo)).decode()
print("Bob's public key: ",enc_point)
vals = Alice_private_key.private_numbers()
print (f"\nAlice private key value: {vals.private_value}")
vals=Alice_private_key.public_key()
enc_point=binascii.b2a_hex(vals.public_bytes(encoding=serialization.Encoding.PEM,format=serialization.PublicFormat.SubjectPublicKeyInfo)).decode()
print("Alice's public key: ",enc_point)
print ("\nBob's derived key: ",binascii.b2a_hex(Bob_derived_key).decode())
print("Alice's derived key: ",binascii.b2a_hex(Alice_derived_key).decode())