Looking for a way to create encrypted filesystems on Linux? Cryptmount is a powerful utility that allows any user to access encrypted filesystems on-demand under GNU/Linux systems without requiring root privileges. . It requires Linux 2.6 or higher. It handles both encrypted partitions as well as encrypted files. It makes it as easy (compared to older approaches such as cryptoloop device driver and dm-cryptdevice-mapper target) for ordinary users to access encrypted filesystems on-demand using the newer devmapper mechanism. Cryptmount helps a system administrator in creating and managing encrypted filesystems based on the kernel’s dm-crypt device-mapper target. . Effortlessly set up and control secure storage areas on Linux with Cryptmount, a robust and intuitive tool.. Encrypted Filesystems, Cryptmount, Linux Encryption Utility, Data Protection, User Access Control. . Brittany Day
Learn how to prevent Linux users from executing certain commands and confining them to their home directory by employing rbash. . You have users logging in to your Linux system. Those users might have not have sudo rights, but they quite possibly could have free rein to poke around most of the system directory tree. You don't want that. Why? Although those users might not be able to edit the vast majority of your configuration files, you certainly don't want those users viewing them. Same holds true for your client data--you want that locked down. But how do you prevent users from being able to access your directory hierarchy without having to tweak the permissions of every file and folder on the system, which could seriously complicate things? The link for this article located at TechRepublic is no longer available. . Learn how to restrict Linux users with rbash: limit their command usage and ensure activities are confined to their home directories with our guide.. Linux User Management, Restricted Shells, RBash Usage, Secure Linux Access. . Brittany Day
Pluggable Authentication Modules is a method for authenticating users.. Pluggable Authentication Modules is a method for authenticating users. Using PAM, programmers can provide a more easy and verstile means of performing authentication functions. The ability to change from basic password authentication to the use of smart cards or even biometrics can be changed without having to recompile programs or require serious modifications. Additionally, PAM can be used to modify the terms of access by users as well as system resources. Just a few of the things you can do with PAM: Use a different encryption method for passwords such as MD5, making them harder to brute force decode; Set resource limits on all your users so they can't perform denial of service attacks (number of processes, amount of memory, etc) Enable shadow passwords on the fly Allow specific users to login only at specific times from specific places Within a few hours of installing and configuring your system, you can prevent many attacks before they even occur. For example, use PAM to disable the system-wide usage of .rhosts files in user's home directories by adding these lines to /etc/pam.d/login : # # Disable rsh/rlogin/rexec for users # login auth required pam_rhosts_auth.so no_rhosts Set filesystem limits instead of allowing unlimited as is the default. You can control the per-user limits using the resource-limits PAM module and /etc/pam.d/limits.conf . For example, limits for group 'users' might look like this: @users hard core 0 @users hard nproc 50 @users hard rss 5000 This says to limit the creation of core files to zero bytes, restrict the number of processes to 50, and restrict memory usage per user to 5 Meg. References The main Linux-PAM has a great deal of (sometimes out-of-date) information on configuring and using PAM. The Linux-PAM System Administrators' Guide is a"draft" document that describes the usage of the default PAM modules. This Red Hat whitepaper on Enhanced Console Access describes how you can configure PAM to authorize ordinary users to access system devices such as the floppy. The Red Hat User Guide contains a section on User Authentication with PAM that explains the basics of PAM as well as some more advanced techniques. Keep in mind that there is the potential to create a situation whereby even root doesn't have access to the system, creating all kinds of configuration headaches. Use caution. . Pluggable Authentication Modules is a method for authenticating users. Using PAM, programmers can pr. pluggable, authentication, modules, method, authenticating, users. . Anthony Pell
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