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Auth & security at scale

OAuth2, JWT, IAM patterns, secrets rotation, and least-privilege service auth.

6 matches

ECDH key agreement in Python with cryptography

Simulate ECDH key exchange between Alice and Bob, derive a shared secret, and generate a symmetric key with HKDF using the cryptography library.

ecdh cryptography key-agreement

Python

from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives import serialization, hashes
from cryptography.hazmat.primitives.kdf.hkdf import HKDF

def ecdh_mock():
    # Alice generates her key pair
    alice_private = ec.generate_private_key(ec.SECP256R1())
    alice_public = alice_pr…

15 0 Open

Auth & security at scale medium

How to Create and Verify HMAC SHA256 API Signatures in Python

Generate and verify HMAC-SHA256 signatures for API requests using Python's hmac, hashlib, and base64 modules.

hmac sha256 authentication

Python

import hmac
import hashlib
import base64
import json
from datetime import datetime, timezone

def create_api_signature(secret_key: str, method: str, path: str, timestamp: str, body: dict = None) -> str:
    """Create HMAC-SHA256 signature for API request."""
    payload = {
        "method": method.upper(),
        "p…

14 0 Open

Auth & security at scale medium

How to Create and Verify an OpenID Connect ID Token in Python

Generate and validate a mock OpenID Connect ID token (JWT) with HS256 signing using only the Python standard library.

jwt oidc security

Python

import base64
import hashlib
import hmac
import json
import time
from typing import Optional


def b64url_encode(data: bytes) -> str:
    return base64.urlsafe_b64encode(data).rstrip(b"=").decode("utf-8")


def b64url_decode(data: str) -> bytes:
    padding = "=" * (-len(data) % 4)
    return base64.urlsafe_b64decode(…

14 0 Open

Auth & security at scale medium

How to Implement a CSRF Token Double Submit Mock in Python

A mock CSRF protection class that generates and validates double-submit tokens using HMAC-SHA256 with a secret key.

csrf security hmac

Python

import hmac
import hashlib
import secrets


class CSRFProtection:
    def __init__(self, secret_key: str):
        self.secret_key = secret_key.encode("utf-8")

    def generate_token(self) -> str:
        random_value = secrets.token_hex(16)
        signature = hmac.new(
            self.secret_key, random_value.enco…

13 0 Open

Auth & security at scale medium

How to Sign and Verify with Ed25519 in Python

A minimal Ed25519 sign-and-verify helper that generates a key pair, signs a message, and checks the signature with the cryptography library.

ed25519 cryptography signing

Python

import hashlib
from cryptography.hazmat.primitives.asymmetric import ed25519
from cryptography.hazmat.primitives import serialization

def sign_verify_mock(
    message: bytes,
    private_key: ed25519.Ed25519PrivateKey,
    public_key: ed25519.Ed25519PublicKey
) -> tuple[bool, bytes]:
    signature = private_key.sign…

13 0 Open

Auth & security at scale medium

How to sign and verify JWT RS256 in Python

Generate RSA keys, create a JWT signed with RS256, verify its signature, and decode the payload using the cryptography library.

jwt rs256 rsa

Python

import json
import time
import base64
import hmac
import hashlib
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.primitives import serialization, hashes
from cryptography.hazmat.primitives.asymmetric import padding
from cryptography.hazmat.primitives.asymmetric.utils import encode_ds…

13 0 Open

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