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name: implementing-mtls-for-zero-trust-services description: > Configures mutual TLS (mTLS) authentication between microservices using Python cryptography library for certificate generation and ssl module for TLS verification. Validates certificate chains, checks expiration, and audits mTLS deployment status. Use when implementing zero-trust service-to-service authentication. domain: cybersecurity subdomain: security-operations tags: [implementing, mtls, for, zero] version: "1.0" author: mahipal license: Apache-2.0

Implementing mTLS for Zero Trust Services

Instructions

Generate CA certificates, issue service certificates, and configure mutual TLS verification for service-to-service authentication.

from cryptography import x509
from cryptography.x509.oid import NameOID
from cryptography.hazmat.primitives import hashes, serialization
from cryptography.hazmat.primitives.asymmetric import rsa
import datetime

# Generate CA key and certificate
ca_key = rsa.generate_private_key(public_exponent=65537, key_size=4096)
ca_cert = (x509.CertificateBuilder()
    .subject_name(x509.Name([x509.NameAttribute(NameOID.COMMON_NAME, "Internal CA")]))
    .issuer_name(x509.Name([x509.NameAttribute(NameOID.COMMON_NAME, "Internal CA")]))
    .public_key(ca_key.public_key())
    .serial_number(x509.random_serial_number())
    .not_valid_before(datetime.datetime.utcnow())
    .not_valid_after(datetime.datetime.utcnow() + datetime.timedelta(days=3650))
    .add_extension(x509.BasicConstraints(ca=True, path_length=None), critical=True)
    .sign(ca_key, hashes.SHA256()))

Examples

import ssl
context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
context.load_cert_chain("client.pem", "client-key.pem")
context.load_verify_locations("ca.pem")
context.verify_mode = ssl.CERT_REQUIRED