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pythonsocketspempyopenssl

PyOpenSSL convert certificate object to .pem file


I want to send a certificate from a "certificate authority" to a node through sockets. I have a certificate created using this example https://skippylovesmalorie.wordpress.com/2010/02/12/how-to-generate-a-self-signed-certificate-using-pyopenssl/ How would I convert this into a .pem file so I can send it as a string through a socket and then convert it on the other end back into a .pem and use get_certificate to extract this certificate from it. Python: reading a pkcs12 certificate with pyOpenSSL.crypto Its probably a hacky way to do it, but I want to simplify it for myself. (or not)

I'm resurrecting the question of this person whos question was not answered How to convert PyOpenSSL object to PEM-encoded string?


Solution

  • This is for generating a certificate signing request, but the concept should be the same

    from OpenSSL import crypto
    
    req = crypto.X509Req()
    pkey = crypto.PKey()
    pkey.generate_key(crypto.TYPE_RSA, 2048)
    req.set_pubkey(pkey)
    req.sign(pkey, 'sha1')
    certreq = crypto.dump_certificate_request(crypto.FILETYPE_PEM, req)
    certreq = certreq.replace('-----BEGIN CERTIFICATE REQUEST-----\n', '').replace('-----END CERTIFICATE REQUEST-----\n', '')
    private_key = crypto.dump_privatekey(crypto.FILETYPE_PEM, pkey)
    

    for a certificate you can use:

    crypto.dump_certificate(type, cert)