How to Enable SHA-3 Support in PAM on Fedora 25

To add SHA-3 support to PAM in Fedora 25, you will need to follow these steps:

1. Install the necessary packages:

sudo dnf install pam-devel openssl-devel

2. Download the latest version of OpenSSL that supports SHA-3 (e.g., OpenSSL 1.1.1 or later) from the OpenSSL website: https://www.openssl.org/source/

3. Extract the downloaded OpenSSL package:

tar -xf openssl-x.x.x.tar.gz

4. Configure and build OpenSSL with SHA-3 support:

cd openssl-x.x.x ./config enable-sha3 make sudo make install

5. Edit the PAM configuration file for the service you want to enable SHA-3 support in. For example, to enable SHA-3 for the system login, edit the `/etc/pam.d/system-auth` file:

sudo vi /etc/pam.d/system-auth

6. Add the following line at the top of the file to enable SHA-3 support:

auth sufficient pam_unix.so sha512

This line tells PAM to use SHA-3 (sha512) as the hashing algorithm for password authentication.

7. Save the file and exit the editor.

8. Repeat steps 5-7 for any other PAM configuration files you want to enable SHA-3 support in.

9. Restart the services that use PAM to apply the changes. For example, to restart the login service:

sudo systemctl restart systemd-logind.service

After following these steps, PAM should now use SHA-3 for password authentication in the specified services.