5
votes
1answer
477 views

What are the OpenSSL standard Diffie Hellmann parameters (primes)?

I recently generated some custom Diffie Hellmann parameters which are basically just long (in the below case 4096 bit) primes. Those are then used in the key exchange process. I used the following ...
1
vote
2answers
717 views

What is the difference between Diffie Hellman generator 2 and 5?

Generating Diffie Hellman parameters in OpenSSL can be done as follows: $ openssl dhparam -out dh2048.pem 2048 Generating DH parameters, 2048 bit long safe prime, generator 2 This is going to take a ...
4
votes
1answer
2k views

OpenVPN dhparam

One of the steps for setting up OpenVPN is running the command openssl dhparam -out dh1024.pem 1024. The man page tells me this 1024 value refers to the number of bits. Why is the value 1024 ...
1
vote
1answer
312 views

OpenSSL DH modp size

If OpenSSL is configured to use a DH for key exchange, e.g. TLS_DHE_RSA_WITH_AES_128_CBC_SHA, where does it take the size for modp (or even modp itself) from? The following is a screenshot from ...
7
votes
3answers
4k views

Can someone explain a little better what exactly is accomplished by generation of DH parameters?

I'm setting up a node.js server: https.createServer({ ... ciphers: 'ECDHE-RSA-AES128-SHA256:AES128-GCM-SHA256:RC4:HIGH:!MD5:!aNULL:!EDH', honorCipherOrder: true }, app).listen(443); ...
10
votes
2answers
6k views

Decrypting TLS in Wireshark when using DHE_RSA ciphersuites

How can I decrypt TLS messages when an ephemeral Diffie-Hellman ciphersuite is used? I am able to expose the premaster secret and master secret from the SSL Client. Using that, how to decrypt the ...