Making Images More Secure
- Security for a device is always a concern.
+ Security is of increasing concern for embedded devices.
Consider the issues and problems discussed in just this
sampling of work found across the Internet:
@@ -3872,15 +3872,14 @@ Gateways via their Web Interfaces"
image secure.
Consequently, this section provides some guidance and suggestions
for consideration when you want to make your image more secure.
-
-
-
- Because the security requirements and risks are
- different for every type of device, this section cannot
- provide a complete reference on securing your custom OS.
- It is strongly recommended that you also consult other sources
- of information on embedded Linux system hardening and on
- security.
+
+ Because the security requirements and risks are
+ different for every type of device, this section cannot
+ provide a complete reference on securing your custom OS.
+ It is strongly recommended that you also consult other sources
+ of information on embedded Linux system hardening and on
+ security.
+
@@ -3928,7 +3927,7 @@ Gateways via their Web Interfaces"
Ensure you remove or disable debugging functionality
before producing the final image.
For information on how to do this, see the
- "Considerations Specific to the OpenEmbedded Build System
+ "Considerations Specific to the OpenEmbedded Build System"
section.
@@ -4009,38 +4008,34 @@ Gateways via their Web Interfaces"
during production.
- It is possible to set a root password for the image.
- When you set up root passwords for multiple images,
- you should not duplicate them.
- See the note on passwords at the end of this list.
+ It is possible to set a root password for the image
+ and also to set passwords for any extra users you might
+ add (e.g. administrative or service type users).
+ When you set up passwords for multiple images or
+ users, you should not duplicate passwords.
- To set up a root password,
- use the extrausers
- class, which is the preferred method.
- For an example on how to set up the root password,
- see the
+ To set up passwords, use the
+ extrausers class, which is the
+ preferred method.
+ For an example on how to set up both root and user
+ passwords, see the
"extrausers.bbclass"
section.
- You can also see the the example in the
- How do I set or change the root password Wiki
- page as an alternative method.
+ When adding extra user accounts or setting a
+ root password, be cautious about setting the
+ same password on every device.
+ If you do this, and the password you have set
+ is exposed, then every device is now potentially
+ compromised.
+ If you need this access but want to ensure
+ security, consider setting a different,
+ random password for each device.
+ Typically, you do this as a separate step after
+ you deploy the image onto the device.
-
- It is possible to add an additional user account
- for later administrative or service access.
- As with root passwords, be sure to not duplicate
- passwords for generic users (e.g. tester, qa, and
- so forth) across multiple devices.
- See the note on passwords following this list.
-
-
- As with the root password, you also use the
- extrausers
- class.
-
Consider enabling a Mandatory Access Control (MAC)
framework (such as SMACK or SELinux) and tuning it
@@ -4050,17 +4045,6 @@ Gateways via their Web Interfaces"
- A Note about Passwords
- When adding extra user accounts or deciding on root
- passwords for multiple devices, be cautious about setting
- the same passwords for multiple users or devices.
- If you want the device to remain secure from unauthorized
- access, and the password set on all devices becomes
- compromised, then every device becomes compromised.
- If you need this access but want to ensure security,
- consider setting a different, random passwords for each
- user or device.
-