<div>
I see rhel5 and rhel6 using 65537 by default.<br />
You can read on how 65537 became default 8 years ago, right before RHEL5 was released.<br />
<a href="https://en.wikipedia.org/wiki/RSA_%28cryptosystem%29#Faulty_key_generation" rel="ugc">https://en.wikipedia.org/wiki/RSA_%28cryptosystem%29#Faulty_key_generation</a><br />
<br />
If you really insist on generating weak keys you can use openssl genrsa which supports them.
</div>


I see rhel5 and rhel6 using 65537 by default.
You can read on how 65537 became default 8 years ago, right before RHEL5 was released.
https://en.wikipedia.org/wiki/RSA_%28cryptosystem%29#Faulty_key_generation [https://en.wikipedia.org/wiki/RSA_%28cryptosystem%29#Faulty_key_generation]

If you really insist on generating weak keys you can use openssl genrsa which supports them.

<div>
Well, on CentOS 6, even updated to the latest version, the following command:<br />
<br />
ssh-keygen -h -f /etc/ssh/ssh_host_rsa_key<br />
<br />
generates the key with exponent 35 (0x23). I need to know the exact command to replicate this behavior on CentOS 7 before one application we use is updated and distributed to all users.
</div>


Well, on CentOS 6, even updated to the latest version, the following command:

ssh-keygen -h -f /etc/ssh/ssh_host_rsa_key

generates the key with exponent 35 (0x23). I need to know the exact command to replicate this behavior on CentOS 7 before one application we use is updated and distributed to all users.

<div>
Thanks for the information, accepting your solution.
</div>


Thanks for the information, accepting your solution.

<div>
<div class="content wysiwyg-content">
Hello,<br />
<br />
I have a rather unusual problem. I will spare you the details, but on one CentOS 7 server I need to create a new RSA key. We would normally use this command:<br />
<br />
ssh-keygen -h -f /etc/ssh/ssh_host_rsa_key<br />
<br />
However, this command creates the key with Public Exponent 65537 (0x10001). But for compatibility reasons with one application I need the key to be created with Public Exponent 35 (0x23), just as was the default with CentOS 5 and CentOS 6.<br />
<br />
Any help would be appreciated.<br />
<br />
Thanks!
</div>
</div>


Hello,

I have a rather unusual problem. I will spare you the details, but on one CentOS 7 server I need to create a new RSA key. We would normally use this command:

ssh-keygen -h -f /etc/ssh/ssh_host_rsa_key

However, this command creates the key with Public Exponent 65537 (0x10001). But for compatibility reasons with one application I need the key to be created with Public Exponent 35 (0x23), just as was the default with CentOS 5 and CentOS 6.

Any help would be appreciated.

Thanks!

Need to create RSA key with forced exponent 35 and using ssh-keygen

The Linux operating system, in all its flavors, has its own share of security flaws that allow intrusions, but there are various mechanisms by which these flaws can be removed, generally divided into two parts: authentication and access control. Authentication is responsible for ensuring that a user requesting access to the system is really the user with the account, while access control is responsible for controlling which resources each account has access to and what kind of access is permitted.

Linux Security

Telnet is an application layer protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communication facility using a virtual terminal connection. SSH was designed as a replacement for Telnet and for unsecured remote shell protocols. The term telnet is also used to refer to the software that implements the client part of the protocol. SSH provides a secure channel over an unsecured network in a client-server architecture, connecting an SSH client application with an SSH server.

SSH / Telnet Software

Linux is a UNIX-like open source operating system with hundreds of distinct distributions, including: Fedora, openSUSE, Ubuntu, Debian, Slackware, Gentoo, CentOS, and Arch Linux. Linux is generally associated with web and database servers, but has become popular in many niche industries and applications.

Linux

Networking is the process of connecting computing devices, peripherals and terminals together through a system that uses wiring, cabling or radio waves that enable their users to communicate, share information and interact over distances. Often associated are issues regarding operating systems, hardware and equipment, cloud and virtual networking, protocols, architecture, storage and management.

Networking

A Linux distribution is an operating system made as a software collection based on the Linux kernel and, often, on a package management system and are available for a variety of systems. A typical Linux distribution comprises a Linux kernel, GNU tools and libraries, additional software, documentation, a window system (the most common being the X Window System), a window manager, and a desktop environment. Most Linux systems are open-source software made available both as compiled binaries and in source code form, allowing modifications to the original software. Over three hundred distributions are in active development, including commercially backed distributions (such as Fedora, openSUSE and Ubuntu) and community-driven distributions (such as Debian, Slackware, Gentoo and Arch Linux).