Using 2048 bit primes in JSch

Question

I am trying to attempt SSH connection from my Java application to an external server of client. The client has enhanced the security and they are not accepting 1024 bit prim

Answer 1

See JSch change log for "Changes since version 0.1.52":

• change: Logjam: diffie-hellman-group-exchange-sha256 and diffie-hellman-group-exchange-sha1 will use 2048-bit key on Java8's SunJCE, thanks to JDK-6521495 and JDK-7044060.

So you are correct that you need JSch 0.1.53, but you also need these fixes in your JDK:

• https://bugs.java.com/bugdatabase/view_bug.do?bug_id=6521495
• https://bugs.openjdk.java.net/browse/JDK-7044060