The OL 8 SSH server must be configured to use strong entropy.
An XCCDF Rule
Description
<VulnDiscussion>The most important characteristic of a random number generator is its randomness, namely its ability to deliver random numbers that are impossible to predict. Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. The SSH implementation in OL 8 uses the OPENSSL library, which does not use high-entropy sources by default. By using the SSH_USE_STRONG_RNG environment variable, the OPENSSL random generator is reseeded from "/dev/random". This setting is not recommended on computers without the hardware random generator because insufficient entropy causes the connection to be blocked until enough entropy is available.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-248563r991593_rule
- Severity
- Low
- References
- Updated
Remediation - Manual Procedure
Configure the operating system SSH server to use strong entropy.
Add or modify the following line in the "/etc/sysconfig/sshd" file.
SSH_USE_STRONG_RNG=32