SAP audit log

This blog will explain the SAP audit log.

Questions that will be answered are:

What is the intended goal of the SAP audit log?
How to switch on the SAP audit log?
What are the recommended settings for the SAP audit log?
What are the common issues with audit logging?
Can I get anonymous access to the audit logging?
How can I get statistics on audit logging?
How can I get a where used list from the audit logging?
How can I archive audit log data for long term storage?
How can I delete audit logging?

Goal of SAP audit log

The goal of the SAP audit log is to capture all audit and security relevant actions. The audit logging function can capture failed logon attempts, dangerous actions like debug & replace, execution of transactions and programs, and many more.

SAP has a note for the frequently asked questions:

Older versions: 539404 – FAQ: Answers to questions about the Security Audit Log.
Newer versions (as of 7.50): 2191612 – FAQ | Use of Security Audit Log as of SAP NetWeaver 7.50

Also interesting read is this note: 3352573 – How to check transactions executed by an user in AS ABAP.

Audit log and privacy

The audit log will capture actions performed in the system. It will not only capture the actions, but also the user ID and terminal ID. This makes the tool a bit of a big brother is watching you tool. Auditors are normally used to dealing with sensitive topics. But next to answering audit questions the audit can also be misused to check ‘is this person doing a lot of work in the system’. For this reason access to audit log should only be given to persons who understand the sensitivity and people privacy. This includes in giving information to managers extracted from the audit log.

Anonymous audit log reporting

In the SAP audit log user names and terminal ID’s are visible. This is in many cases privacy information. Due to privacy rules and regulations the audit log access might be very restricted or cumbersome. Especially when the audit logging is to be used for analysis purposes, rather than for audit. If OSS note 2883981 – RSAU_READ* | anonymized display of Security Audit Log data is applied, a new transaction is created. This new transaction, RSAU_READ_LOG_ADM, shows all the information, but now with user ID and terminal ID columns in anonymous mode.

Switching on the audit log

For switching on the audit log first the corresponding system parameters must be set:

rsau/enable: set to 1 to enable
rsau/local/file: set the file location in format “/usr/sap/<SID>/<instno>/log/
audit_<SAP_instance_number>” (yes, unfortunately audit log still uses a file)
rsau/max_diskspace_local: max disk space (set to at least 1 GB)
rsau/selection_slots: default is 2, but typically this is set to 10 slots

Unfortunately these parameters are not dynamic, which means a system restart is required to activate these parameters.

After the activation you can go to transaction SM19 (or in newer version to RSAU_CONFIG) to switch on the audit logging in detail.

First step is to create a profile and activate it.

Next step is to setup the filters.

Audit log filters

The audit log filters are used to filter events. If you select all events this will cause logging shadow and make the function unreliable.

To configure the filters use transaction RSAU_CONFIG (this is replacing old SM19 transaction).

Main client versus 000, 001 and 066 client

SAP has multiple clients. The 000, 001 and 066 client are only used by system admins. For these clients you can setup a special filter and log ALL actions for ALL users. This will not cause too many entries.

If you want to fully avoid SAPSYS entries, follow the instructions from this blog section.

Main client logging settings

In the main client you have to be selective on the checks.

The audit log has 3 classification of checks:

Critical (always switch these on!)
Severe (if possible switch on as well)
Uncritical (be very selective for switching these on)

Key filters recommendations

ALWAYS switch on the critical checks. This will include:

Debug & replace actions
Debug start
Changes to audit log configuration itself
User creation
Failed logon attempts
User locks due to wrong password

From the severe and uncritical sections the following checks are useful:

Logon failed: this can help to detect logon attempts with standard users (see blog on SAP standard users): the audit log will capture the terminal ID from which the attempt happened
Start of report failed: will avoid discussions if people really could start or not
Report started: though in many productive systems SE38 etc is not allowed for directly starting a report outside a transaction code, this still will happen by admins and firefighter. This check will log which direct report is started
Transaction locked and unlocked: capture locking and unlocking of transactions with SM01 in old systems (and SM01_DEV and SM01_CUS in newer systems)
Transaction started: this will avoid discussion if people key in the tcode or not (do remember that audit log captures the start; it can still be user is not authorized to continue with the transaction). And many RBE (reverse business engineering) type of tools rely on this audit log tracing rather than the ST03 logging. Reason is that the audit log is on user level rather then aggregated level and is usually kept longer.
User deleted, user locked and user unlocked
Password changed for user

SE92 audit log details

Using transaction SE92 you can get a more easy overview of the settings definitions as provided by SAP for the audit log details. Read more in this blog.

RSAU_CONFIG configuration overview

Using transaction RSAU_CONFIG you can get a more easy overview of the actual activation and configuration.

Audit log reporting

Transaction codes SM20 or RSAU_READ_LOG can be used to view the audit log results.

Be careful to whom you give the rights to read the audit log.

Audit log settings overview

You can use transaction RSAU_CONFIG_SHOW to get an overview of the audit log settings.

New checks

With every new SAP release SAP improves the audit log. By default the audit logging is not updated after an upgrade. Therefore it is wise to check for new items added to the audit log after an upgrade.

Determining changes to audit log settings

OSS note 2680888 – SAL | Report for determination of differences in event parameters is delivering new report RSAU_READ_LOG_DIFF to show changes done to the audit log configuration:

Delete SAP audit log files

Start transaction RSAU_ADMIN and start the option for log file reorganization:

Or you can run/schedule program RSAUPURG.

Restricted access to this function is a must.

Archiving audit logging

There might be requirements from security or business side that require you to find a solution for long term storage of the audit log data. Deletion as explained above could not be an option for you.

To archive audit logging data, activate the settings for archiving object BC_SAL. Read this blog on the exact technical execution of archiving runs.

OSS notes to be applied for the audit log archiving function:

Issues with audit logging

There are some known issues with the audit logging.

Logging shadow

If too much items are selected in the filters the audit logging will grow very fast. If the audit log is full, it will start to overwrite the earlier entries. The earlier entries are then lost. This is called logging shadow. Depending on your requirements, you have to increase the disk space, and better: check which item in the audit log settings you don’t need, but do cause extensive amount of logging.

Large SAP systems with multiple application servers

On large SAP systems with multiple application servers, the file handling can cause issues. If the system is setup using shared files and the names of the profile configuration per application server for the file name is identical, this will cause nasty issue. The issue is that the audit logging from several application servers will overwrite each other entries. This is hard to detect. Solutions: don’t use shared file, or change the profile parameter per application server to include the application server name into the audit log file name. To do this set the FN_AUDIT parameter to this value: SQL_++++++++.AUD. Upon runtime the +’s will be replaced with the application server name.

See point 25 in the audit log FAQ note 539404 – FAQ: Answers to questions about the Security Audit Log. And point 12 in the new (as of Netweaver 7.50) note 2191612 – FAQ | Use of Security Audit Log as of SAP NetWeaver 7.50.

Audit logging integrity

Based on the settings in OSS note 2033317 – Integrity protection format for Security Audit Log, you can switch on the audit logging integrity. This way you can prove nobody tampered with the audit log. But this also means you cannot read the audit logfile on file level or by any third party tool. Please consider this carefully and read the note about other effects and prerequisites first before switching on.

Where used list and audit log statistics

On newer versions (or via notes below) there are 2 new programs available:

RSAU_GET_STAT for statistical information
RSAU_GET_WUSL for a where used list of security events

To get this function apply these OSS notes:

Audit log self check

To get this function apply the same notes as for the audit log statistics:

Then you can run program RSAU_SELF_CHECK_DIA.

If you want to run the Still Alive Check:

You first have to make sure to activate Audit test event AU0:

Auditing user SAP*

If you need to audit user SAP*, the * is a wildcard. You have to use the escaped version: SAP#*. See SAP help link.

Background OSS notes and blogs

Logging incidents for SAL (SAP Audit Log): 3295213 – Required information for analyzing issues with the Security Audit Log (AS ABAP) within the new SAL environment.

Useful background OSS notes and blogs are:

Known bugs and bug fixing OSS notes

Bug fixing OSS notes: