get public key from private key with python OpenSSL

Question

Well, I generate a private key with pyOpenSSL as follows:

from OpenSSL import crypto
k = crypto.PKey()
k.generate_key(crypto.TYPE_RSA, 2048)
print crypto.dump_privatekey(crypto.FILETYPE_PEM, k)

How do I get the public key string from it? I've still not found what method of this library does it. Thanks

You appear to have printed it in the last line of your code. As @danodonovan says below. Edit: sorry, not paying attention. — wrgrs, Feb 18 '13 at 15:00

score 3 · Accepted Answer · answered Feb 18 '13 at 14:58

If

cert = crypto.dump_certificate(crypto.FILETYPE_PEM, k)

doesn't do what you want, then it doesn't look like pyOpenSSL supports public key dumping. There is an unmerged branch here that adds that functionality but I can't claim that it does what is purports.

score 1 · Answer 2 · answered Nov 29 '22 at 09:58

1

Updated: Now it has the method to get public key directly.

key = crypto.PKey()
key.generate_key(crypto.TYPE_RSA, 2048)
publickey_contents = crypto.dump_publickey(crypto.FILETYPE_PEM, key)

with the method dump_publickey you can get what you want.

answered Nov 29 '22 at 09:58

Ron

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get public key from private key with python OpenSSL

2 Answers2