The SSH daemon must be configured to use a FIPS 140-2 compliant cryptographic algorithm.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-224044	TSS0-SH-000020	SV-224044r877882_rule		High

Description
Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000120-GPOS-00061, SRG-OS-000250-GPOS-00093

STIG	Date
IBM z/OS TSS Security Technical Implementation Guide	2023-03-20

Details

Check Text ( C-25717r516758_chk )
Locate the SSH daemon configuration file which may be found in /etc/ssh/ directory. Alternately: From UNIX System Services ISPF Shell navigate to ribbon select tools. Select option 1 - Work with Processes. If SSH Daemon is not active, this is not a finding. Examine SSH daemon configuration file. sshd_config If there are no Ciphers lines or the ciphers list contains any cipher not starting with "3des" or "aes", this is a finding. If the MACs line is not configured to "hmac-sha1" or greater, this is a finding. Examine the z/OS-specific sshd server system-wide configuration: zos_sshd_config If any of the following is untrue, this is a finding. FIPSMODE=YES CiphersSource=ICSF MACsSource=ICSF

Check Text ( C-25717r516758_chk )

Locate the SSH daemon configuration file which may be found in /etc/ssh/ directory.

Alternately:
From UNIX System Services ISPF Shell navigate to ribbon select tools.
Select option 1 - Work with Processes.

If SSH Daemon is not active, this is not a finding.

Examine SSH daemon configuration file.
sshd_config

If there are no Ciphers lines or the ciphers list contains any cipher not starting with "3des" or "aes", this is a finding.

If the MACs line is not configured to "hmac-sha1" or greater, this is a finding.

Examine the z/OS-specific sshd server system-wide configuration:
zos_sshd_config

If any of the following is untrue, this is a finding.

FIPSMODE=YES
CiphersSource=ICSF
MACsSource=ICSF

Fix Text (F-25705r516759_fix)
Edit the SSH daemon configuration and remove any ciphers not starting with "3des" or "aes". If necessary, add a "Ciphers" line using FIPS 140-2 compliant algorithms.