"serialization.load_pem_private_key()"

Python Tutorials - Herong's Tutorial Examples

∟"serialization.load_pem_private_key()" - Load EC Private Key

This section provides a tutorial example on how to use 'cryptography.hazmat.primitives.serialization.load_pem_private_key' method to load an EC private key in PEM format in Python scripts.

If you want to read an EC private key in PEM format, you can use the cryptography.hazmat.primitives.module. Here is a Python example script that loads an EC private key:

# cryptography-hazmat-ec-load.py
# Copyright (c) 2025, HerongYang.com, All Rights Reserved.
#
import sys
if (len(sys.argv) < 2):
  print("Usage: python cryptography-hazmat-ec-load.py file")
  exit()
file = sys.argv[1]

from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives import serialization

with open(file, "rb") as key_file:
  private_key = serialization.load_pem_private_key(
    key_file.read(), None
  )

if isinstance(private_key, ec.EllipticCurvePrivateKey):
  print("Curve name: "+private_key.curve.__class__.__name__)
  print("Key size: "+str(private_key.key_size))
  print(f"x: {private_key.private_numbers().public_numbers.x}")
  print(f"y: {private_key.private_numbers().public_numbers.y}")
  print(f"d: {private_key.private_numbers().private_value}")

else:
  raise TypeError

Save the EC private key generated from the last tutorial in a file called private-key.pem and run the above script:

herong$ python3 cryptography-hazmat-ec-load.py private-key.pem  

Curve name: SECP256R1
Key size: 256
x: 1448598621669265146687495365245166001695582165426594859805879...
y: 3746487251185212638022777276660681179127648368273248695396648...
d: 2771254253714437992124662222726178157117638306617714749456695...