File and Directory Permissions
To help ensure secure authentication, and prevent tampering, information leakage and spoofing, files and directories used by the client and server must be configured with correct permissions and ownership. If these conditions aren't met, Secure Shell connections and public key authentication may fail.
Notes:
- The StrictModes setting helps ensure enforcement of a satisfactory level of security and is enabled by default on both the server and the client.
- Files must be owned by root or by the owner of the home directory in which the files reside.
- Where permission requirements are enforced, the permissions must be at the level indicated in the table below, or more restrictive (less than or equal to the octal value shown in brackets).
- Files and directories shown in parentheses are the defaults.
Client-side files and directories
File or |
Maximum |
Required when |
Required when |
|---|---|---|---|
Secure Shell directory (~/.ssh2/) |
700 |
No requirements |
User-only write access [755] |
User home directory and |
744 |
No requirements |
User-only write access [755] |
User’s private keys |
600 |
User-only read/write access [600] |
User-only read/write access [600] |
User's public keys |
600 |
No requirements |
No requirements |
User's identification file (~/.ssh2/identification) |
600 |
No requirements |
User-only write access [644] |
User's host keys directory (~/.ssh2/hostkeys) |
700 |
No requirements |
No requirements |
Host public key files |
600 |
No requirements |
No requirements |
User's configuration file (~/.ssh2/ssh2_config) |
600 |
No requirements |
User-only write access [644] |
Client PKI Services Manager public key (specified using PkidPublicKey) |
600 |
No requirements |
No requirements |
Global configuration directory (/etc/ssh2/) |
755 |
No requirements |
No requirements |
Global host keys directory (/etc/ssh2/hostkeys) |
755 |
No requirements |
No requirements |
Global host public key files |
644 |
No requirements |
No requirements |
Global user configuration file (/etc/ssh2/ssh2_config) |
644 |
No requirements |
No requirements |
Server-side files and directories (user-specific)
File or |
Maximum |
Required when |
Required when |
|---|---|---|---|
Secure Shell directory (~/.ssh2/) |
700 |
No requirements |
User-only write access [755] |
User home directory and |
744 |
No requirements |
User-only write access [755] |
User's authorization file on the server (~/.ssh2/authorization) |
600 |
User-only write access [644] |
User-only write access [644] |
User’s secure shell environment file on the server (~/.ssh2/environment) |
600 |
No requirements |
No requirements |
User's login behavior file (~/.hushlogin) |
600 |
No requirements |
No requirements |
Server-side files and directories (global)
File or |
Maximum |
Required when |
Required when |
|---|---|---|---|
Server configuration directory (/etc/ssh2) |
644 |
No requirements |
No requirements |
Server private key file (/etc/ssh2/hostkey) |
600 |
Root-only read/write access [600] |
Root-only read/write access [600] |
Server public key file (/etc/ssh2/hostkey.pub |
600 |
No requirements |
No requirements |
Server RADIUS authentication configuration file (/etc/ssh2/radius_config) |
600 |
No requirements |
No requirements |
Subconfiguration file directory (/etc/ssh2/subconfig) |
700 |
No requirements |
No requirements |
Subconfiguration files |
600 |
No requirements |
No requirements |
Global Secure Shell environment file (/etc/ssh2/environment) |
600 |
No requirements |
No requirements |
Client PKI Services Manager public key (specified using PkidPublicKey) |
600 |
No requirements |
No requirements |
 |