Troubleshoot SAML SSO

Here are some common issues and how to resolve them.

Error message: SAML fails to verify assertions

You see the following error message:

Failed to verify the assertion - The 'Audience' field in the saml response 
from the IdP does not match the configuration

Mitigation

1. The SAML errors are recorded in the splunkd.log on the search head. You can see the complete error message by running a search on that search head:

index=_internal sourcetype=splunkd SAML error

You should see the following:

09-18-2017 14:58:06.939 +0000 ERROR Saml - Failed to verify the assertion - The 'Audience' 
field in the saml response from the IdP does not match the configuration, Error 
details=Expected=https://<instance_name>.com, found=https://<wrong_instance_name>.com/

2. Modify authentication.conf with the entityId found in the error message in step 1.

[saml]
entityId= https://<instance_name>.com/ (found from ERROR message) 

3. Reload authentication.conf from Splunk Web at Settings > Access Controls > Authentication Method > Reload Authentication configuration

Error message: Leaf certificate does not match

You receive the following message:

No leaf certificate matched one from the assertion

This error occurs when the signature certificate on Splunk does not match the certificate that the IdP uses to sign SAML messages.

Mitigation

If your signature verification certificate is a self-signed certificate:

Make sure that the certificate specified in the idpCertPath attribute in authentication.conf is the same as the certificate the IdP uses to sign SAML messages. You can use OpenSSL to determine the details of the certificate that Splunk uses for signature verification.

For example, the following command:

openssl x509 -in etc/auth/idpCerts/idpCert.pem -text -noout |  grep 'Serial\|Issuer:\|Subject:'

Should produce information similar to this:

Serial Number: 1478287046063 (0x15830c635af)
Issuer: C=US, ST=CA, L=San Francisco, O=Splunk, OU=Splunk Service, 
CN=5165ffd1bf1a0363c8a5cd8062337fb4
Subject: C=US, ST=CA, L=San Francisco, O=Splunk, OU=Splunk Service, 
CN=5165ffd1bf1a0363c8a5cd8062337fb4

If the signature verification certificate is part of a certificate chain

Make sure that the signing certificates match and are consistently named. For example, a simple chain would have three files in the following order:

• the root CA, for example: "cert_1.pem"
• the intermediate certificate, for example: "cert_2.pem"
• the leaf certificate or the signing certificate, for example: "cert_3.pem"

In this example, make sure that the "cert_3.pem" (the leaf) is the same certificate that the IdP uses to sign responses.

If you have multiple chains, or chains with more than one intermediate CA

In most cases, the certificate chain consist of a single root certificate, a single intermediate certificate, and a single signing certificate. However, you may have multiple chains configured, or more than one intermediate CA.

If you have multiple chains configured, structure your certificate chain as follows:

$SPLUNK_HOME/etc/auth/idpCerts
idpCertChain_1 idpCertChain_2
$SPLUNK_HOME/etc/auth/idpCerts/idpCertChain_1
cert_1.pem  cert_2.pem  cert_3.pem
$SPLUNK_HOME/etc/auth/idpCerts/idpCertChain_2
cert_1.pem  cert_2.pem  cert_3.pem

If you have more than one intermediate CA

If you have more than one intermediate CA, structure your certificate chain as follows:

$SPLUNK_HOME/etc/auth/idpCerts
idpCertChain_1
$SPLUNK_HOME/etc/auth/idpCerts/idpCertChain_1
cert_1.pem cert_2.pem cert_3.pem cert_4.pem cert_5.pem

Error message: Attribute query request error

Issue: You experience the following message

ERROR AuthenticationManagerSAML - Requesting user info from ID returned an error. Error in Attribute
query request, AttributeQueryTransaction err=Cannot resolve hostname, AttributeQueryTransaction 
descr=Error resolving: Name or service not known, AttributeQueryTransaction statusCode=502

Mitigation

• Make sure that the cipherSuite is specified correctly in the SAML stanza. For example:
  • cipherSuite = TLSv1+MEDIUM:@STRENGTH
  • cipherSuite = ALL:!aNULL:!eNULL:!LOW:!EXP:RC4+RSA:+HIGH:+MEDIUM

• Make sure all SOAP password requirements are met.

• Make sure your SSL settings for SAML are configured correctly in authentication.conf.

Issue: You experience the following message:

ERROR AuthenticationManagerSAML - Attribute query request failed. Status 
code=urn:oasis:names:tc:SAML:2.0:status:UnknownPrincipal, Status msg=No attributes found for 
requested subject

Mitigation

• Make sure that the role, mail, and realName attributes are mapped to be returned back as part of AuthnRequest and the Attribute Query Request.

Error message: SAML user missing roles

You experience the following message:

ERROR UserManagerPro - user="samluser1" had no roles

Mitigation

Make sure that rolemap_SAML contains the correct role mapping with ";" at the end of each role name.

User cannot login

User cannot log in after successful assertion validation. No valid Splunk role is found in the local mapping or in the assertion.

Mitigation

• Make sure that rolemap_SAML stanza contains proper mapping between roles returned from IdP and the appropriate Splunk role.

• Make sure there are no spaces between, before, or after each role defined in authentication.conf. For example:

user = User;Employee

User cannot access SAML login page

Authentication is configured as SAML and the settings appear to be correct, but the login screen shows the page for Splunk authentication instead.

Mitigation

• Make sure that in web.conf, appServerPorts is set to a valid port and not '0'.

• Make sure web.conf does not contain a value for trustedIP.

Error message: Failed to validate SAML logout response

When you log out of Splunk Enterprise or Splunk Cloud, you see the following error message:

Failed to validate SAML logout response received from IdP

Mitigation

This might be caused by case-sensitive IdPs that expect Splunk software to preserve uppercase letters in usernames. You can change the username to lowercase in the IdP or configure the IdP to accept the lowercase version of a username.

Cannot authenticate users for CLI commands

Unable to authenticate SSO users for CLI commands

Mitigation

You can add the SAML users as native Splunk users.

API and CLI commands cannot be performed by users that are defined only in SAML. This is because the user password is never sent in the SAML assertion.