How to extract RSA public-key from x509 certificate in python
<p>I have the following script. It connects to a TLS server and extracts X509 certificate public-key:</p>

<pre><code>import socket, ssl
import OpenSSL

hostname='www.google.com'
port=443

context = ssl.SSLContext(ssl.PROTOCOL_TLSv1_2)

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
ssl_sock = context.wrap_socket(s, server_hostname=hostname)
ssl_sock.connect((hostname, port))
ssl_sock.close()
print("ssl connection Done")

cert = ssl.get_server_certificate((hostname, port))
# OpenSSL
x509 = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, cert)
pk = x509.get_pubkey()
print(pk)
</code></pre>

<p>The problem is that the returned public-key. I need it in hexadecimal format. How to solve this issue? </p>

<p>This is the output I am getting:</p>

<pre><code>&lt;OpenSSL.crypto.PKey object at 0x0000019EBFDF73C8&gt;
</code></pre>