pyopenssl_rsa_keypair_self_signed_x509_certificate_generation.py

1from OpenSSL import crypto
2
3# Generate a 2048-bit RSA key pair
4key = crypto.PKey()
5key.generate_key(crypto.TYPE_RSA, 2048)
6
7# Create a self-signed certificate
8cert = crypto.X509()
9cert.get_subject().C = "US"
10cert.get_subject().ST = "California"
11cert.get_subject().L = "San Francisco"
12cert.get_subject().O = "My Organization"
13cert.get_subject().OU = "My Organizational Unit"
14cert.get_subject().CN = "example.com"
15cert.set_serial_number(1000)
16cert.gmtime_adj_notBefore(0)
17cert.gmtime_adj_notAfter(10*365*24*60*60)
18cert.set_issuer(cert.get_subject())
19cert.set_pubkey(key)
20cert.sign(key, 'sha256')
21
22# Write the private key and certificate to files
23with open("selfsigned.crt", "wt") as f:
24    f.write(crypto.dump_certificate(crypto.FILETYPE_PEM, cert).decode("utf-8"))
25with open("selfsigned.key", "wt") as f:
26    f.write(crypto.dump_privatekey(crypto.FILETYPE_PEM, key).decode("utf-8"))