The audit logging feature provides a detailed record of every transaction handled by the IdP to allow tracing of user activity, statistical analysis of usage, legal record keeping, etc. It is highly extensible, allowing the format to be customized, selection of fields to log on a per-profile basis, and the addition of custom audit fields using additional Java code or scriptlets without modifying core code in most cases. Unlike the diagnostic logs, the audit log is meant to be machine-readable.
The primary audit stream deals with the request/response profile handling of the IdP itself (this also includes logging the requests and responses associated with the SAML proxying support). This is routed by default through a logger named "Shibboleth-Audit" to a file called idp-audit.log.
Another audit record stream exists for logging decisions made by users regarding attribute release and terms of use acceptance and is routed by default through a logger named "Shibboleth-Consent-Audit" to a file called idp-consent-audit.log.
Prior to V4.3, the audit log does not include records of individual authentication success or failure results; only the diagnostic (“process”) log includes (unstructured) records of those events. V4.3 introduces a separate stream of authentication audit events for each supported login flow. By default this feature is not enabled, but if done, these records appear in the same audit stream as the primary auditing. It is straightforward (and usually advisable) to route these records by category to a separate file or destination since the record format is not the same as the primary records.
Finally, the primary audit log supports the ability to create multiple log records in different formats or with different fields at the same time for the same events (and optionally route them to different categories for output to different destinations). The authentication auditing does not support this feature for simplicity (and because of the relative paucity of fields).
General Configuration
As with the diagnostic logs, the actual logging is handled by the Logback implementation and so the portion of configuration that deals with how the logs are written and managed is in the conf/logback.xml file through the manipulation of the two <logger> elements and related content for the "Shibboleth-Audit" and "Shibboleth-Consent-Audit" categories.
However, there is minimal formatting applied there, just direct output of the audit message. The configuration of the audit format(s) to use for particular transactions is handled separately, in conf/audit.xml, to allow customizing of the audit fields themselves, using formatting tokens that are themselves configured within the IdP and are extensible. You can think of it like a second logging abstraction on top of the underlying one to avoid reliance on Logback-specific extensions.
There are really two halves to the auditing system: field extraction and log output. While suitable defaults are provided, both halves can be changed using conf/audit.xml (or conf/intercept/consent-intercept-config.xml for the “Shibboleth-Consent-Audit” category). Extending field extraction typically requires additional Java code or scripts to pull new data out of the request state and make it available to the log output stage, but there are a lot of built-in fields.
Field extraction is the process of populating a labeled field in an AuditContext object that is built up over the life of a transaction. The context is just a map of field names to collections of values and the field names are just conventions built-in to the software to provide a standard set of useful fields to audit.
Fields are extracted at various points through the life of a transaction so that adequate detail can be exposed about the request, the processing of the request, and the response. These extraction points are associated with collections of field extraction beans that do the actual work to pull data out of the state of the transaction and store it for output.
The built-in extraction points and beans are as follows (empty beans are not provided to reduce clutter, but you can add them, per the example below):
shibboleth.FlowStartAuditExtractors
Extractors that run immediately after the flow starts operating and the ability to add fields is possible
shibboleth.PostDecodeAuditExtractors
Extractors focused on the input message, runs after decoding the input message
shibboleth.PostLookupAuditExtractors
Runs after establishing the sender's identity, supplements the input side with information about the relying party
shibboleth.PostAssertionAuditExtractors
Extractors focused on authentication, session, and attribute information, runs after those processes and after the initial creation of the outgoing assertion (if relevant to the request)
shibboleth.PostResponseAuditExtractors
Extractors focused on the outgoing message, runs after construction of the message
shibboleth.LogoutRequestAuditExtractors
Extractors focused on information specific to a SAML LogoutRequest message, runs after decoding of the message
shibboleth.LogoutAuditExtractors
Extractors focused on information in a non-SAML logout
shibboleth.ErrorViewAuditExtractors
Extracts subject, session, and attribute information, runs in the event that a local error is generated
shibboleth.consent.PreConsentAuditExtractors
Extracts basic information about the consent step, runs before a decision is made
Empty map beans are declared in conf/intercept/consent-intercept-config.xml
shibboleth.consent.ConsentAuditExtractors
Extracts information about the decision, runs after a decision is made
Empty map beans are declared in conf/intercept/consent-intercept-config.xml
shibboleth.PostRequestAuditExtractors
Extractors for an AuthnRequest built for proxied SAML SSO
shibboleth.PostInboundResponseAuditExtractors
Extractors for a Response from proxied SAML SSO
shibboleth.PostInboundAssertionAuditExtractors
Extractors for Assertions from proxied SAML SSO
Each entry in these maps is a key containing the string label to associate (the name of the field), and a value containing a Function<ProfileRequestContext,Object> instance. Functions can return either single objects that get converted to a string for logging, or a Collection of objects that are converted to strings and separated by commas within the logged field.
In this manner, you can add your own fields by implementing a function (or writing a script) to return any data you can find in the context tree and associating it with a custom field label by adding it to one of the maps named above.
In V4.3+, a similar extractor exists for each login flow in the IdP, allowing different auditing behavior per-flow. All these beans have names based on the underlying login flow (e.g. shibboleth.authn.Password.AuditExtractors, etc.)
A skeletal example follows to demonstrate how to create a map to contain a custom field extraction rule:
Adding custom fields to the audit log via audit.xml
<!-- Adds a function to extract a custom field called MYFIELD after the final response has been generated. -->
<bean id="shibboleth.PostResponseAuditExtractors" parent="shibboleth.DefaultPostResponseAuditExtractors">
<property name="sourceMap">
<map merge="true">
<entry key="MYFIELD" value-ref="MyExtractionFunctionBean" />
</map>
</property>
</bean>
A real world example: if you're logging fields containing a URL, you may need to escape characters in a URL because of the delimiter you choose to use in the log format. You can do this using a script:
Encoding 'pipe' character appearing in CAS service URLs
<bean id="shibboleth.CASValidationAuditExtractors" parent="shibboleth.DefaultCASValidationAuditExtractors" lazy-init="true">
<property name="sourceMap">
<map merge="true">
<entry>
<key>
<util:constant static-field="net.shibboleth.idp.cas.protocol.CASAuditFields.SERVICE_URL"/>
</key>
<bean parent="shibboleth.ContextFunctions.Scripted" factory-method="inlineScript">
<constructor-arg>
<value>
<![CDATA[
var serviceLookupFunctionClass = Java.type("net.shibboleth.idp.cas.audit.impl.ServiceLookupFunction");
var serviceLookupFunction = new serviceLookupFunctionClass();
var service = serviceLookupFunction.apply(input);
if (service != null) {
var serviceNew = service.replace(/\|/g, '%7C');
}
else {
var serviceNew = null;
}
serviceNew;
]]>
</value>
</constructor-arg>
</bean>
</entry>
</map>
</property>
</bean>
A rather more convoluted example is to dump the values or arbitrary attributes into the log. To do this we define an abstract bean to emit the attribute values (in an arbitrary format) for any attribute (most of this is really error and null handling):
Output Attribute Values
<bean id="AttributeValueExtraction" parent="shibboleth.ContextFunctions.Scripted" factory-method="inlineScript" abstract="true">
<constructor-arg>
<value>
<![CDATA[
var getinfo = function() {
var rpContext = input.getSubcontext("net.shibboleth.idp.profile.context.RelyingPartyContext");
if (null === rpContext) {
return null;
}
var attrContext = rpContext.getSubcontext("net.shibboleth.idp.attribute.context.AttributeContext");
if (null === attrContext) {
return null;
}
var attributes = null
attributes = attrContext.getUnfilteredIdPAttributes();
if (null === attributes) {
return null;
}
attribute = attributes.get(custom);
if (null === attribute || attribute.getValues().isEmpty()) {
return null;
}
var iter = attribute.getValues().iterator();
var result = "";
while (iter.hasNext()) {
result = result + " " + iter.next().toString();
}
return result;
}
getinfo();
]]>
</value>
</constructor-arg>
</bean>
Then a bean to emit a specific attribute can be easily created:
The generic fields that are supported out of the box are as follows (note that not every field is always populated; that depends on the timing of errors and the specific transaction being audited):
The more SAML-oriented fields that are supported out of the box are as follows (note that not every field is always populated; that depends on the timing of errors and the specific transaction being audited):
Field
Description
Field
Description
SP
Service provider name
IDP
Identity provider name
p
Protocol
b
Inbound binding
bb
Outbound binding
RS 4.1
RelayState
n
NameID value
f
NameID format
SPQ
NameID SPNameQualifier
pf
NameIDPolicy required format
PSPQ
NameIDPolicy required SPNameQualifier
i
Assertion ID
d
Assertion timestamp
I
Inbound message ID
D
Inbound message timestamp
II
InResponseTo
III
Outbound message ID
DD
Outbound message timestamp
t
AuthenticationInstant
x
SessionIndex
ac
AuthenticationContext
S
Status code
SS
Sub-status code
SM
Status message
pasv
IsPassive
fauth
ForceAuthn
SCC 4.2
Scoping ProxyCount from an AuthnRequest
SCI 4.2
Scoping IdP list from an AuthnRequest
SCR 4.2
Scoping Requester ID(s) from an AuthnRequest
PRC 4.2
ProxyRestriction ProxyCount
PRA 4.2
ProxyRestriction Audiences
XX
Signed inbound messages
X
Encrypted assertions
XA
Encryption algorithm
A few fields are defined for auditing specific information during authentication, which is a V4.3 feature; many are specific to particular login flows.
Field
Description
Field
Description
tu
Transformed username submitted for validation (Password flow only)
AR
Results of authentication attempt, either “Success” or classified error strings
CV
Specific CredentialValidator bean used (Password flow only)
X509S
Certificate subject (X.509 flows only)
X509I
Certificate issuer (X.509 flows only)
DuoCID
Duo client identifier/integration key (Duo flow only)