Blockchain_School/goodchain/src/helpers/SignatureHelper.py
2023-11-08 15:11:41 +01:00

85 lines
2.5 KiB
Python

from cryptography.exceptions import *
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import padding
from cryptography.hazmat.backends import default_backend
def generateKeys():
private_key = rsa.generate_private_key(public_exponent=65537,key_size=2048)
public_key = private_key.public_key()
return private_key, public_key
def keysToBytes(private_key, public_key):
prv_ser = privateKeyToBytes(private_key)
pbc_ser = publicKeyToBytes(public_key)
return prv_ser, pbc_ser
def publicKeyToBytes(public_key):
pbc_ser = public_key.public_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PublicFormat.SubjectPublicKeyInfo)
return pbc_ser
def privateKeyToBytes(private_key):
prv_ser = private_key.private_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PrivateFormat.TraditionalOpenSSL,
encryption_algorithm=serialization.NoEncryption())
return prv_ser
def bytesToKeys(private_ser, public_ser):
private_key = serialization.load_pem_private_key(
private_ser,
password=None
)
public_key = serialization.load_pem_public_key(
public_ser
)
return private_key, public_key
def publicBytesToKey(public_ser):
public_key = serialization.load_pem_public_key(
public_ser,
backend=default_backend()
)
return public_key
def privateBytesToKey(private_ser):
private_key = serialization.load_pem_private_key(
private_ser,
password=None,
backend=default_backend()
)
return private_key
def sign(message, private_key):
message = bytes(str(message), 'utf-8')
signature = private_key.sign(
message,
padding.PSS(mgf=padding.MGF1(hashes.SHA256()), salt_length=padding.PSS.MAX_LENGTH),
hashes.SHA256()
)
return signature
def verify(message, signature, public_ser):
message = bytes(str(message), 'utf-8')
public_key = publicBytesToKey(public_ser)
try:
public_key.verify(
signature,
message,
padding.PSS(mgf=padding.MGF1(hashes.SHA256()),
salt_length=padding.PSS.MAX_LENGTH),
hashes.SHA256()
)
return True
except InvalidSignature:
return False
except:
print("Error executing 'public_key.verify'")
return False