cifscreds

cifscreds is a Linux command-line utility used to manage user credentials for accessing CIFS (Common Internet File System) network file systems, such as those mounted via SMB (Server Message Block). It allows users to add, update, and delete credentials (username and password) for CIFS network shares, which can be cached in the kernel for future authentication.

Purpose

• Manage Credentials for CIFS Mounts: cifscreds simplifies the process of managing credentials required to access CIFS network shares. This is particularly useful for shares requiring user authentication, such as those found on Windows servers or Samba shares.

• Automate Authentication: Instead of entering credentials each time the share is accessed, users can cache their credentials, enabling automatic authentication when accessing the CIFS mount.

• Kerberos Authentication Support: cifscreds also supports caching Kerberos tickets, which can be used for seamless authentication to CIFS mounts in Kerberos-enabled environments.

Basic Syntax

cifscreds <command> [options] <target>

• <command>: Specifies the operation to perform (add, clear, update, or clearall).

• <target>: Specifies the CIFS server (hostname or IP address) or share for which the credentials are being managed.

Common Commands

1. Add Credentials

   This command caches the credentials for a specified CIFS server or share:

   cifscreds add <target>

   The command prompts for the username and password.

2. Update Credentials

   This command updates the cached credentials for a specific CIFS server or share:

   cifscreds update <target>

   It will prompt for the new password.

3. Clear Credentials

   This command clears the cached credentials for a specific CIFS server or share:

   cifscreds clear <target>

4. Clear All Credentials

   This command clears all cached credentials in the kernel for CIFS mounts:

   cifscreds clearall

Example Usage

1. Add Credentials for a CIFS Share

   To cache the credentials (username and password) for a share on fileserver.company.com:

   cifscreds add fileserver.company.com

   The command will prompt for a username and password.

2. Update Credentials

   If the password for the CIFS share has changed, you can update the cached credentials:

   cifscreds update fileserver.company.com

3. Clear Credentials

   To remove the cached credentials for a specific share:

   cifscreds clear fileserver.company.com

4. Clear All Credentials

   To remove all cached credentials from the kernel:

   cifscreds clearall

Security Considerations

• User-Specific: The cached credentials are stored in the kernel and are specific to the user who ran the cifscreds command. This ensures that credentials are not shared across users.

• Password Prompt: The command prompts for passwords in a secure manner and does not expose them in the command line or shell history.

• Time-Limited Caching: Depending on system configuration, credentials cached by cifscreds may have a time limit after which they expire. Re-authentication may be required once they expire.

Use Cases

• CIFS Network Mounts with Credentials: For users who frequently access CIFS shares that require authentication, cifscreds provides an efficient way to manage credentials without needing to store them in fstab or other configuration files.

• Kerberos Environments: In networks using Kerberos, cifscreds can cache Kerberos tickets for CIFS shares, enabling transparent authentication across Kerberos-enabled CIFS/SMB servers.

Conclusion

cifscreds is a powerful utility for managing CIFS share credentials in Linux. It allows for seamless and secure access to network shares by caching credentials, simplifying the authentication process for users who frequently interact with CIFS/SMB file systems. Whether for individual file access or large-scale network shares, cifscreds helps streamline the authentication process while maintaining secure handling of credentials.