smb-encrypt

smb-encrypt is a Samba configuration parameter that controls the encryption of SMB (Server Message Block) traffic between a Samba server and its clients. Enabling SMB encryption helps protect sensitive data during transit, ensuring that communications are secure even over untrusted networks.

Overview

• Purpose: To encrypt data transmitted between the Samba server and its clients, protecting it from eavesdropping and interception.

• Configuration Level: This setting can be applied globally in the [global] section of smb.conf or on a per-share basis within individual share definitions.

• Encryption Modes: Common values for smb encrypt include:

  • desired: Encrypt the connection if the client supports it; however, non-encrypted connections are still allowed.

  • required: Enforce encryption for all connections; non-encrypted clients will be denied access.

  • enabled: Force encryption on all connections without negotiation.

  • off: Disable SMB encryption.

Configuration Examples

Global Configuration

To require encryption for all SMB traffic on the server, add the following line in your [global] section of smb.conf:

[global]
   smb encrypt = required

Per-Share Configuration

You can also enforce encryption on specific shares. For example, to require encryption for a share named secure_share:

[secure_share]
   path = /srv/samba/secure
   read only = no
   smb encrypt = required

In this configuration, any client accessing secure_share must use an encrypted connection.

Use Cases

• Sensitive Data Transfer: Enforce encryption on shares containing confidential or sensitive data to protect it from interception.

• Remote Access Over Untrusted Networks: When clients connect from outside a secure corporate network (e.g., over the Internet), encryption ensures data privacy.

• Regulatory Compliance: Meet compliance requirements (such as HIPAA, PCI-DSS, or GDPR) that mandate encrypted data transmission.

Considerations

• Performance Impact: Encrypted connections may incur a performance overhead. Test the configuration to ensure that it meets your performance requirements.

• Client Compatibility: Ensure that client systems support SMB encryption. Most modern Windows and Unix clients do, but older systems may not.

• Balanced Security: Choose the appropriate mode based on your environment. Use desired in less-critical environments where performance is a priority, and required or enabled where security is paramount.

Conclusion

The smb-encrypt parameter is essential for securing SMB communications in a Samba environment. By configuring it either globally or on a per-share basis, administrators can protect data in transit, ensure compliance with security policies, and provide a secure network experience for all users.