Manage Certificates

Certificate Management in Cisco ISE

A certificate is an electronic document that identifies an individual, a server, a company, or another entity, and associates that entity with a public key. A self-signed certificate is signed by its creator. Certificates can be self-signed or digitally signed by an external CA. A CA-signed digital certificate is considered an industry standard and more secure than a self-signed certificate.

Certificates are used in a network to provide secure access. Certificates identify a Cisco ISE node to an endpoint and secure the communication between that endpoint and the Cisco ISE node.

Cisco ISE uses certificates for:

Communication between Cisco ISE nodes.
Communication between Cisco ISE and external servers such as the syslog and feed servers.
Communication between Cisco ISE and end user portals such as guest, sponsor and BYOD portals.

Manage certificates for all the nodes in your deployment through the Cisco ISE administration portal.

Configure Certificates in Cisco ISE to Enable Secure Access

Cisco ISE relies on public key infrastructure (PKI) to provide secure communication with both endpoints and administrators and between Cisco ISE nodes in a multinode deployment. PKI relies on X.509 digital certificates to transfer public keys for encryption and decryption of messages, and to verify the authenticity of other certificates representing users and devices. Through the Cisco ISE administration portal, you can manage two categories of X.509 certificates:

System Certificates: These are server certificates that identify a Cisco ISE node to client applications. Every Cisco ISE node has its own system certificates that are stored on the node along with the corresponding private keys.

Note

Cisco ISE cannot import more than one certificate with the same private key. If the certificate is renewed and imported without changing the private key, then the existing certificate is replaced with the imported certificate.

Trusted Certificates: These are CA certificates that are used to establish trust for the public keys that are received from users and devices. The Trusted Certificates store also contains certificates that are distributed by the Simple Certificate Enrollment Protocol (SCEP), which enables the registration of mobile devices into the enterprise network. Trusted certificates are managed on the primary PAN, and are automatically replicated to all the other nodes in a Cisco ISE deployment.

In a distributed deployment, you must import the certificate only into the Certificate Trust List (CTL) of the PAN. The certificate gets replicated to the secondary nodes.

To ensure certificate authentication in Cisco ISE is not impacted by minor differences in certificate-driven verification functions, use lowercase hostnames for all Cisco ISE nodes that are deployed in a network.

Certificate Usage

When you import a certificate into Cisco ISE, specify the purpose for which the certificate is to be used. Choose Administration > System > Certificates > System Certificates, and click Import.

Choose one or more of the following uses:

Admin: For internode communication and authenticating the administration portal.
EAP Authentication: For TLS-based EAP authentication.
RADIUS DTLS: For RADIUS DTLS server authentication.
Portal: For communicating with all Cisco ISE end-user portals.
SAML: For verifying that the SAML responses are being received from the correct identity provider.
pxGrid: For communicating with the pxGrid controller.

Associate different certificates from each node for communicating with the administration portal (Admin usage), the pxGrid controller (pxGrid usage), and for TLS-based EAP authentication (EAP Authentication usage). However, you can associate only one certificate from each node for each of these purposes.

With multiple PSNs in a deployment that can service a web portal request, Cisco ISE needs a unique identifier to identify the certificate that must be used for portal communication. When you add or import certificates that are designated for portal use, define a certificate group tag and associate it with the corresponding certificate on each node in your deployment. Associate this certificate group tag to the corresponding end-user portals (guest, sponsor, and personal devices portals). This certificate group tag is the unique identifier that helps Cisco ISE identify the certificate that must be used when communicating with each of these portals. You can only designate one certificate from each node for each of the portals.

Note

An EAP-TLS client certificate should have KeyUsage=Key Agreement and ExtendedKeyUsage=Client Authentication for the following ciphers:

ECDHE-ECDSA-AES128-GCM-SHA256
ECDHE-ECDSA-AES256-GCM-SHA384
ECDHE-ECDSA-AES128-SHA256
ECDHE-ECDSA-AES256-SHA384

An EAP-TLS client certificate should have KeyUsage=Key Encipherment and ExtendedKeyUsage=Client Authentication for the following ciphers:

AES256-SHA256
AES128-SHA256
AES256-SHA
AES128-SHA
DHE-RSA-AES128-SHA
DHE-RSA-AES256-SHA
DHE-RSA-AES128-SHA256
DHE-RSA-AES256-SHA256
ECDHE-RSA-AES256-GCM-SHA384
ECDHE-RSA-AES128-GCM-SHA256
ECDHE-RSA-AES256-SHA384
ECDHE-RSA-AES128-SHA256
ECDHE-RSA-AES256-SHA
ECDHE-RSA-AES128-SHA
EDH-RSA-DES-CBC3-SHA
DES-CBC3-SHA
RC4-SHA
RC4-MD5

To bypass this requirement, choose Administration > System > Settings > Security Settings and check the Accept certificates without validating purpose checkbox.

Certificate Matching in Cisco ISE

When you set up Cisco ISE nodes in a deployment, the nodes communicate with each other. The system checks the FQDN of each Cisco ISE node to ensure that they match (for example ise1.cisco.com and ise2.cisco.com or if you use wildcard certificates then *.cisco.com). In addition, when an external machine presents a certificate to a Cisco ISE server, the external certificate that is presented for authentication is checked (or matched) against the certificate in the Cisco ISE server. If the two certificates match, the authentication succeeds.

For Cisco , matching is performed between the nodes (if there are two), and between Cisco and pxGrid.

Cisco ISE checks for a matching subject name as follows:

Cisco ISE looks at the subject alternative name extension of the certificate. If the subject alternative name contains one or more DNS names, then one of the DNS names must match the FQDN of the Cisco ISE node. If a wildcard certificate is used, then the wildcard domain name must match the domain in the Cisco ISE node’s FQDN.
If there are no DNS names in the subject alternative name, or if the subject alternative name is missing entirely, then the common name in the Subject field of the certificate or the wildcard domain in the Subject field of the certificate must match the FQDN of the node.

If no match is found, the certificate is rejected.

Note

X.509 certificates that are imported into Cisco ISE must be in privacy-enhanced mail (PEM) or distinguished encoding rule format. Files containing a certificate chain (a system certificate along with the sequence of trust certificates that sign it) can be imported, subject to certain restrictions.

Validity of X.509 Certificates

X.509 certificates are valid until a specific date. When a system certificate expires, the Cisco ISE functionality that depends on the certificate is impacted. Cisco ISE notifies you about the pending expiration of a system certificate when the expiration date is within 90 days. This notification appears in several ways:

Colored expiration status icons appear in the System Certificates window. The navigation path is Administration > System > Certificate Management > System Certificates.
Expiration messages appear in the Cisco ISE System Diagnostic report. The navigation path isOperations > Reports > Reports > Diagnostics > System Diagnostic.
Expiration alarms are generated 90 days, 60 days, and 30 days before expiration. Expiration alarms are generated every day in the final 30 days before expiration.

If the expiring certificate is a self-signed certificate, you can extend its expiration date by editing the certificate. For a certificate authority-signed certificate, you must allow sufficient time to acquire the replacement certificate from your certificate authority.

Enable Public Key Infrastructure in Cisco ISE

PKI is a cryptographic technique that enables secure communication and verifies the identity of a user using digital signatures.

Procedure

Step 1

Configure system certificates on each node in your deployment for the following:

TLS-enabled authentication protocols such as EAP-TLS.
Administration portal authentication.
Allow browser and REST clients to access Cisco ISE web portals.
Allow access to pxGrid controller.

By default, a Cisco ISE node is preinstalled with a self-signed certificate that is used for EAP authentication, and for access to administration portal, end user portals, and pxGrid controller. In a typical enterprise environment, this self-signed certificate is replaced with server certificates that are signed by a trusted CA.

Step 2

Populate the Trusted Certificates store with the CA-signed certificates that are used to establish trust with the user, and device certificates that will be presented to Cisco ISE.

To validate the authenticity of a user or device certificate with a certificate chain that consists of a root CA certificate and one or more intermediate CA certificates:

Enable the relevant trust option for the root CA.

In the Cisco ISE GUI, choose Administration > System >Certificates > Certificate Management > Trusted Certificates. In this window, check the check box for the root CA certificate and click Edit. In the Usage area, check the necessary check boxes in the Trusted For area.
If you do not want to enable the trust option for the root CA, import the entire CA-signed certificate chain into the Trusted Certificates store.

For inter-node communications, you must populate the Trusted Certificates store with the trust certificates that validate the Admin system certificate of each node in the Cisco ISE deployment. To use the default self-signed certificate for internode communication, export this certificate from the System Certificates window of each Cisco ISE node and import it into the Trusted Certificates store. If you replace the self-signed certificates with CA-signed certificates, it is only necessary to populate the Trusted Certificates store with the appropriate root CA and intermediate CA certificates. You cannot register a node in a Cisco ISE deployment until you complete this step.

If you use self-signed certificates to secure communication between a client and a PSN in a deployment, when BYOD users move from one location to another, EAP-TLS user authentication fails. For such authentication requests that have to be serviced between a few PSNs, you must secure communication between the client and the PSN with an externally-signed CA certificate or use wildcard certificates that are signed by an external CA.

If you intend to get a publicly signed certificate or if the Cisco ISE deployment is to be operated in FIPS mode, you must ensure that all system and trusted certificates are FIPS-compliant. This means that each certificate must have a minimum key size of 2048 bytes, and use SHA-1 or SHA-256 encryption.

Note

After you obtain a backup from a standalone Cisco ISE node or the PAN, if you change the certificate configuration on one or more nodes in your deployment, you must obtain another backup to restore data. Otherwise, if you try to restore data using the older backup, communication between the nodes might fail.

Wildcard Certificates

A wildcard certificate uses a wildcard notation (an asterisk and period before the domain name) and the certificate can be shared across multiple hosts in an organization. For example, the CN value for the certificate subject would be a generic hostname such as aaa.ise.local and the SAN field would include the same generic hostname and a wildcard notation such as DNS.1=aaa.ise.local and DNS.2=*.ise.local.

If you configure a wildcard certificate to use *.ise.local, you can use the same certificate to secure any other host whose DNS name ends with “.ise.local,” such as :

aaa.ise.local
psn.ise.local
mydevices.ise.local
sponsor.ise.local

Wildcard certificates secure communication in the same way as a regular certificate, and requests are processed using the same validation methods.

The following figure is an example of a wildcard certificate that is used to secure a website.

Figure 1. Example of Wildcard Certificate

Wildcard Certificate Support in Cisco ISE

Cisco ISE supports wildcard certificates. In earlier releases, Cisco ISE verified any certificate enabled for HTTPS to ensure the common name field matches the FQDN of the host exactly. If the fields did not match, the certificate could not be used for HTTPS communication.

In earlier releases, Cisco ISE used that common name value to replace the variable in the url-redirect A-V pair string. For all centralized web authentication, onboarding, posture redirection, and so on, the common name value was used.

Cisco ISE uses the hostname of the ISE node as the common name.

Wildcard Certificates for HTTPS and Extensible Authentication Protocol Communication

You can use wildcard server certificates in Cisco ISE for administration (web-based services) and EAP protocols that use SSL or TLS tunneling. When you use wildcard certificates, you do not need to generate a unique certificate for each Cisco ISE node. Also, you no longer have to populate the SAN field with multiple FQDN values to prevent certificate warnings. Use an asterisk (*) in the SAN field to share a single certificate across multiple nodes in a deployment and prevent certificate name mismatch warnings. However, the use of wildcard certificates is considered less secure than assigning a unique server certificate to each Cisco ISE node.

When assigning public wildcard certificates to the guest portal and importing sub-CA with root-CA certificates, the certificate chain is not sent until Cisco ISE services are restarted.

Note

If you use wildcard certificates, we recommend that you partition your domain space for greater security. For example, instead of *.example.com, you can partition it as *.amer.example.com. If you do not partition your domain, it could lead to serious security issues.

Wildcard certificates use an asterisk (*) and a period before the domain name. For example, the common name value for a certificate’s Subject Name would be a generic hostname such as aaa.ise.local and the SAN field would have the wildcard character such as *.ise.local. Cisco ISE supports wildcard certifications in which the wildcard character (*) is the left-most character in the presented identifier. For example, *.example.com or *.ind.example.com. Cisco ISE does not support certificates in which the presented identifier contains other characters along with the wildcard character. For example, abc*.example.com, or a*b.example.com, or *abc.example.com.

Fully Qualified Domain Name in URL Redirection

Authorization profile redirects are carried out for central web authentication, device registration web authentication, native supplicant provisioning, mobile device management, client provisioning, and posture services. When Cisco ISE builds an authorization profile redirect, the resulting cisco-av-pair includes a string similar to the following:

url-redirect=https://ip:port/guestportal/gateway?sessionId=SessionIdValue&action=cwa

When processing this request, Cisco ISE substitutes actual values for some keywords in this string. For example, SessionIdValue is replaced with the actual session ID of the request. For an eth0 interface, Cisco ISE replaces the IP in the URL with the FQDN of the Cisco ISE node. For non-eth0 interfaces, Cisco ISE uses the IP address in the URL. You can assign a host alias (name) for interfaces eth1 through eth3, which Cisco ISE can then substitute in place of IP address during URL redirection.

To do this, use the ip host command in the configuration mode from the Cisco ISE CLI ISE /admin(config)# prompt:

ip host IP_address host-alias FQDN-string

Where IP_address is the IP address of the network interface (eth1 or eth2 or eth3) and host-alias is the name that you assign to the network interface. FQDN-string is the fully qualified domain name of the network interface. Using this command, you can assign a host-alias or an FQDN-string or both to a network interface.

Here is an example using the ip host command: ip host a.b.c.d sales sales.amerxyz.com

After you assign a host alias to the non-eth0 interface, restart the application services on Cisco ISE using the application start ise command.

Use the no form of this command to remove the association of the host alias with the network interface.

no ip host IP_address host-alias FQDN-string

Use the show running-config command to view the host alias definitions.

If you provide the FQDN-string, Cisco ISE replaces the IP address in the URL with the FQDN. If you provide only the host alias, Cisco ISE combines the host alias with the configured IP domain name to form a complete FQDN and replaces the IP address in the URL with the FQDN. If you do not map a network interface to a host alias, then Cisco ISE uses the IP address of the network interface in the URL.

When you use non-eth0 interfaces for client provisioning or native supplicant or guest flows, ensure that the IP address or host alias for non-eth0 interfaces are configured appropriately in the PSN certificate's SAN fields.

Advantages of Using Wildcard Certificates

Cost savings: Certificates that are signed by third-party CAs are expensive, especially as the number of servers increases. Wildcard certificates can be used on multiple nodes in the Cisco ISE deployment.
Operational efficiency: Wildcard certificates allow all PSNs to share the same certificate for EAP and web services. In addition to significant cost savings, certificate administration is also simplified by creating the certificate once and applying it on all the PSNs.
Reduced authentication errors: Wildcard certificates address issues seen with Apple iOS devices when the client stores trusted certificates within the profile and does not follow the iOS keychain where the signing root is trusted. When an iOS client first communicates with a PSN, it does not explicitly trust the PSN certificate, although a trusted CA has signed the certificate. Using a wildcard certificate, the certificate is the same across all PSNs, so the user only has to accept the certificate once and successive authentications to different PSNs proceed without errors or prompts.
Simplified supplicant configuration: For example, a Microsoft Windows supplicant with PEAP-MSCHAPv2 and a trusted server certificate requires that you specify each of the server certificate to trust, or the user may be prompted to trust each PSN certificate when the client connects using a different PSN. With wildcard certificates, a single server certificate can be trusted rather than individual certificates from each PSN.
Wildcard certificates result in an improved user experience with less prompting and more seamless connectivity.

Disadvantages of Using Wildcard Certificates

The following are some of the security considerations that are related to the use of wildcard certificates:

Loss of auditability and nonrepudiation.
Increased exposure of the private key.
Not common or understood by administrators.

Wildcard certificates are considered less secure than using a unique server certificate in each Cisco ISE node. But cost and other operational factors outweigh the security risk.

Security devices such as Cisco Adaptive Security Appliance also support wildcard certificates.

You must be careful when deploying wildcard certificates. For example, if you create a certificate with *.company.local and an attacker is able to recover the private key, that attacker can spoof any server in the company.local domain. Therefore, it is considered a best practice to partition the domain space to avoid this type of compromise.

To address this possible issue and to limit the scope of use, wildcard certificates may also be used to secure a specific subdomain of your organization. Add an asterisk (*) in the subdomain area of the common name where you want to specify the wildcard.

For example, if you configure a wildcard certificate for *.ise.company.local, that certificate may be used to secure any host whose DNS name ends in “.ise.company.local”, such as:

psn.ise.company.local
mydevices.ise.company.local
sponsor.ise.company.local

Wildcard Certificate Compatibility

Wildcard certificates are usually created with the wildcard listed as the common name of the certificate subject. Cisco ISE supports this type of construction. However, not all endpoint supplicants support the wildcard character in the certificate subject.

All the Microsoft native supplicants that were tested (including Windows Mobile which is now discontinued) do not support wildcard character in the certificate subject.

You can use another supplicant, such as Cisco AnyConnect Network Access Manager that might allow the use of wildcard characters in the Subject field.

You can also use special wildcard certificates such as DigiCert's Wildcard Plus that is designed to work with incompatible devices by including specific subdomains in the Subject Alternative Name of the certificate.

Although the Microsoft supplicant limitation appears to be a deterrent to using wildcard certificates, there are alternative ways to create the wildcard certificate that allow it to work with all the devices tested for secure access, including the Microsoft native supplicants.

To do this, instead of using the wildcard character in the Subject, you must use the wildcard character in the Subject Alternative Name field instead. The Subject Alternative Name field maintains an extension that is designed for checking the domain name (DNS name). See RFC 6125 and RFC 2128 for more information.

Certificate Hierarchy

In the administration portal, view the certificate hierarchy or the certificate trust chain of all endpoint, system, and trusted certificates. The certificate hierarchy includes the certificate, all the intermediate CA certificates, and the root certificate. For example, when you choose to view a system certificate from the the administration portal, the details of the corresponding system certificate are displayed. The certificate hierarchy is displayed at the top of the certificate. Click a certificate in the hierarchy to view its details. The self-signed certificate does not have any hierarchy or trust chain.

In the certificate listing windows, you will see one of the following icons in the Status column:

Green icon: Indicates a valid certificate (valid trust chain).
Red icon: Indicates an error (for example, trust certificate missing or expired).
Yellow icon: Warns that a certificate is about to expire and prompts renewal.

System Certificates

Cisco ISE system certificates are server certificates that identify a Cisco ISE node to other nodes in the deployment and to client applications. System certificates are:

Used for inter-node communication in a Cisco ISE deployment. Check the Admin check box in the Usage area of these certificates.
Used by browser and REST clients who connect to Cisco ISE web portals. Check the Portal check box in the Usage area of these certificates.
Used to form the outer TLS tunnel with PEAP and EAP-FAST. Check the EAP Authentication check box in the Usage area for mutual authentication with EAP-TLS, PEAP, and EAP-FAST.
Used for RADIUS DTLS server authentication.
Used to communicate with SAML identity providers. Check the SAML check box in the Usage area of this certificate. If you choose the SAML option, you cannot use this certificate for any other service.
Used to communicate with the pxGrid controller. Check the pxGrid check box in the Usage area of these certificates.

Install valid system certificates on each node in your Cisco ISE deployment. By default, two self-signed certificates and one signed by the internal Cisco ISE CA are created on a Cisco ISE node during installation time:

A self-signed server certificate designated for EAP, Admin, Portal, and RADIUS DTLS (it has a key size of 2048 and is valid for one year).
A self-signed SAML server certificate that can be used to secure communication with a SAML identity provider (it has a key size of 2048 and is valid for one year).
An internal Cisco ISE CA-signed server certificate that can be used to secure communication with pxGrid clients (it has a key size of 4096 and is valid for one year).

When you set up a deployment and register a secondary node, the certificate that is designated for pxGrid controller is automatically replaced with a certificate that is signed by the primary node's CA. Thus, all pxGrid certificates become part of the same PKI trust hierarchy.

Note

When you export a wildcard system certificate to be imported into the other nodes (for inter-node communication), ensure that you export the certificate and the private key, and specify an encryption password. During import, you will need the certificate, private key, and encryption password.
Cisco ISE supports the use of RSASSA-PSS algorithm only for trusted certificates and endpoint certificates for EAP-TLS authentication. When you view the certificate, the signature algorithm is listed as 1.2.840.113549.1.1.10 instead of the algorithm name.

Cisco ISE does not support system certificates that use RSASSA-PSS as the signature algorithm. This is applicable for the server certificate, root certificate, and intermediate CA certificate.

For supported key and cipher information for your release, see the appropriate version of the Cisco Identity Services Engine Network Component Compatibility guide.

We recommend that you replace the self-signed certificate with a CA-signed certificate for greater security. To obtain a CA-signed certificate, you must:

Create a Certificate-Signing Request and Submit it to a Certificate Authority
Import a Root Certificate to Trusted Certificate Store
Bind a CA-Signed Certificate to a Certificate Signing Request

ISE Community Resource

How To: Implement ISE Server-Side Certificates

Certificate Renewal on Cisco Identity Services Engine Configuration Guide

View System Certificates

The System Certificate window lists all the system certificates added to Cisco ISE.

Before you begin

To perform the following task, you must be a Super Admin or System Admin.

Procedure

Step 1

Choose Administration > System > Certificates > System Certificates.

Step 2

The following columns are displayed in the System Certificates window:

Friendly Name: Name of the certificate.
Usage: The services for which this certificate is used.
Portal group tag: Applicable only for certificates that are designated for portal use. This field specifies which certificate has to be used for portals.
Issued To: Common Name of the certificate subject.
Issued By: Common Name of the certificate issuer
Valid From: Date on which the certificate was created, also known as the "Not Before" certificate attribute.
Valid To (Expiration): Expiration date of the certificate, also known as the "Not After" certificate attribute. The following icons are displayed next to the expiration date:
- Green icon: Expiring in more than 90 days.
- Blue icon: Expiring in 90 days or less.
- Yellow icon: Expiring in 60 days or less.
- Orange icon: Expiring in 30 days or less.
- Red icon: Expired.

Import a System Certificate

You can import a system certificate for any Cisco ISE node from the administration portal.

Note

Changing the certificate of the admin role certificate on a primary PAN node restarts services on all other nodes. The system restarts one node at a time, after the primary PAN restart has complete.

Before you begin

Ensure that you have the system certificate and the private key file on the system that is running on the client browser.
If the system certificate that you import is signed by an external CA, import the relevant root CA and intermediate CA certificates into the Trusted Certificates store (Administration > System > Certificates > Trusted Certificates).
If the system certificate that you import contains basic constraints extension with the CA flag set to true, ensure that the key usage extension is present, and the keyEncipherment bit or the keyAgreement bit or both are set.
To perform the following task, you must be a Super Admin or System Admin.

Procedure

Step 1	Choose Administration > System > Certificates > System Certificates.
Step 2	Click Import. The Import Server Certificate window is displayed.
Step 3	Enter the values for the certificate that you are going to import.
Step 4	Click Submit.

Generate a Self-Signed Certificate

Add a new local certificate by generating a self-signed certificate. Cisco recommends that you only employ self-signed certificates for your internal testing and evaluation needs. If you plan to deploy Cisco ISE in a production environment, use CA-signed certificates whenever possible to ensure more uniform acceptance around a production network.

Note

If you use a self-signed certificate and you want to change the hostname of your Cisco ISE node, log in to the administration portal of the Cisco ISE node, delete the self-signed certificate that has the old hostname, and generate a new self-signed certificate. Otherwise, Cisco ISE continues to use the self-signed certificate with the old hostname.

Before you begin

To perform the following task, you must be a Super Admin or System Admin.

Edit a System Certificate

Use this window to edit a system certificate and to renew a self-signed certificate. When you edit a wildcard certificate, the changes are replicated to all the nodes in the deployment. If you delete a wildcard certificate, that wildcard certificate is removed from all the nodes in the deployment.

Before you begin

To perform the following task, you must be a Super Admin or System Admin.

Procedure

Step 1	Choose Administration > System > Certificates > System Certificates.
Step 2	Check the check box next to the certificate that you want to edit, and click Edit.
Step 3	To renew a self-signed certificate, check the Renewal Period check box and enter the expiration Time to Live (TTL) in days, weeks, months, or years. Choose the required value from the drop-down lists.
Step 4	Click Save. If the Admin check box is checked, then the application server on the Cisco ISE node restarts. In addition, if the Cisco ISE node is the PAN in a deployment, then the application server on all the other nodes in the deployment also restart. The system restarts one node at a time, after the primary PAN restart has completed.

Note

Using Chrome 65 and above to launch Cisco ISE can cause BYOD portal or Guest portal to fail to launch in the browser although URL is redirected successfully. This is because of a new security feature introduced by Google that requires all certificates to have a Subject Alternative Name field. For Cisco ISE Release 2.4 and later, you must fill the Subject Alternative Name field.

To launch with Chrome 65 and above, follow the steps below:

1. Generate a new self-signed certificate from the Cisco ISE GUI by filling the Subject Alternative Name field. Both DNS and IP Address must be filled.

2. Cisco ISE services restart.

3. Redirect the portal in Chrome browser.

4. From browser View Certificate>Details>Copy the certificate by selecting base-64 encoded.

5. Install the certificate in Trusted path.

6. Close the Chrome browser and try to redirect the portal.

Note

When configuring wireless BYOD setup for the browser Firefox 64 and later releases, with operating systems Win RS4 or RS5, you may not be able to add Certificate Exception. This behaviour is expected in case of fresh installs of Firefox 64 and later releases, and does not occur in case of upgrading to Firefox 64 and above from a previous version. The following steps allow you to add certificate exception in this case:

Configure for BYOD flow single or dual PEAP or TLS.
Configure CP Policy with Windows ALL option.
Connect Dot1.x or MAB SSID in end client Windows RS4 or Windows RS5.
Type 1.1.1.1 in FF64 browser for redirection to Guest or BYOD portal.
Click Add Exception > Unable to add certificate, and proceed with flow.

As a workaround, add the certificate manually for Firefox 64. In the Firefox 64 browser, choose Options > Privacy & Settings > View Certificates > Servers > Add Exception.

Delete a System Certificate

You can delete the system certificates that you no longer use.

Although you can delete multiple certificates from the System Certificates store at a time, you must have at least one certificate to use for Admin and EAP authentication. Also, you cannot delete any certificate that is in use for Admin, EAP Authentication, Portals, or pxGrid controller. However, you can delete the pxGrid certificate when the service is disabled.

If you choose to delete a wildcard certificate, the certificate is removed from all the Cisco ISE nodes in the deployment.

Procedure

Step 1

Administration > System > Certificates > System Certificates.

Step 2

Check the check boxes next to the certificates that you want to delete, and click Delete.

A warning message is displayed.

Step 3

Click Yes to delete the certificate.

Export a System Certificate

You can export a system certificate or a certificate and its associated private key. If you export a certificate and its private key for backup purposes, you can reimport them later if needed.

Before you begin

To perform the following task, you must be a Super Admin or System Admin.

Procedure

Step 1

Administration > System > Certificates > System Certificates.

Step 2

Check the check box next to the certificate that you want to export and click Export.

Step 3

Choose whether to export only the certificate, or the certificate and its associated private key.

Tip

We do not recommend exporting the private key that is associated with a certificate because its value may be exposed. If you must export a private key (for example, when you export a wildcard system certificate to be imported into the other Cisco ISE nodes for inter-node communication), specify an encryption password for the private key. You must specify this password while importing this certificate into another Cisco ISE node to decrypt the private key.

Step 4

Enter the password if you have chosen to export the private key. The password should be at least eight characters long.

Step 5

Click Export to save the certificate to the file system that is running your client browser.

If you export only the certificate, the certificate is stored in the PEM format. If you export both the certificate and private key, the certificate is exported as a .zip file that contains the certificate in the PEM format and the encrypted private key file.

Trusted Certificates Store

The Trusted Certificates store contains X.509 certificates that are used for trust and for Simple Certificate Enrollment Protocol (SCEP).

The certificates in the Trusted Certificate store are managed on the primary PAN, and are replicated to every node in the Cisco ISE deployment. Cisco ISE supports wildcard certificates.

Cisco ISE uses the trusted certificates for the following purposes:

To verify client certificates used for authentication by endpoints, and by Cisco ISE administrators accessing ISE-PICthe administration portal using certificate-based administrator authentication.
To enable secure communication between Cisco ISE nodes in a deployment. The Trusted Certificates store must contain the chain of CA certificates needed to establish trust with the system certificate on each node in a deployment.
- If a self-signed certificate is used for the system certificate, the self-signed certificate from each node must be placed in the Trusted Certificates store of the PAN.
- If a CA-signed certificate is used for the system certificate, the CA root certificate, and any intermediate certificates in the trust chain, must be placed in the Trusted Certificates store of the PAN.
To enable Secure LDAP authentication, a certificate from the certificate store must be selected when defining an LDAP identity source that will be accessed over SSL.

To distribute to personal devices preparing to register in the network using the personal devices portals. Cisco ISE implements the SCEP on PSNs to support personal device registration. A registering device uses the SCEP protocol to request a client certificate from a PSN. The PSN contains a registration authority (RA) that acts as an intermediary. The RA receives and validates the request from the registering device and then forwards the request to an external CA or the internal Cisco ISE CA, which issues the client certificate. The CA sends the certificate back to the RA, which returns it to the device.

Each SCEP CA used by Cisco ISE is defined by a SCEP RA profile. When a SCEP RA profile is created, two certificates are automatically added to the Trusted Certificates store:

A CA certificate (a self-signed certificate)
An RA certificate (a Certificate Request Agent certificate), which is signed by the CA.

The SCEP protocol requires that these two certificates be provided by the RA to a registering device. By placing these two certificates in the Trusted Certificates store, they are replicated to all PSN nodes for use by the RA on those nodes.

Note

When a SCEP RA profile is removed, the associated CA chain is also removed from the Trusted Certificates store. However, if the same certificates are referenced by secure syslog, LDAP, system, or trust certificates, only the SCEP profile is deleted.

Note

X.509 certificates imported to Cisco ISE must be in PEM or Distinguished Encoding Rule format. Files containing a certificate chain, a system certificate along with the sequence of trust certificates that sign it, are imported, subject to certain restrictions.
When assigning public wildcard certificates to the guest portal and importing sub-CA with root-CA certificates, the certificate chain is not sent until the Cisco ISE services restart.

ISE Community Resource

Install a Third-Party CA Certificate in ISE 2.0

Certificates in Trusted Certificates Store

The Trusted Certificate store is prepopulated with trusted certificates: manufacturing certificate, root certificate, and other trusted certificates. The Root certificate (Cisco Root CA) signs the Manufacturing (Cisco CA Manufacturing) certificate. These certificates are disabled by default. If you have Cisco IP phones as endpoints in your deployment, enable the root and manufacturing certificates so the Cisco-signed client certificates for the phones are authenticated.

Trusted Certificate Naming Constraints

A trusted certificate in CTL may contain a name constraint extension. This extension defines a namespace for values of all subject name and subject alternative name fields of subsequent certificates in a certificate chain. Cisco ISE does not check constraints that are specified in a root certificate.

Cisco ISE supports the following name constraints:

Directory name

The directory name constraint should be a prefix of the directory name in the subject or subject alternative name field. For example:
- Correct subject prefix:
  
  CA certificate name constraint: Permitted: O=Cisco
  
  Client certificate subject: O=Cisco,CN=Salomon
- Incorrect subject prefix:
  
  CA certificate name constraint: Permitted: O=Cisco
  
  Client certificate subject: CN=Salomon,O=Cisco
DNS
Email
URI (The URI constraint must start with a URI prefix such as http://, https://, ftp://, or ldap://).

Cisco ISE does not support the following name constraints:

IP Address
OtherName

When a trusted certificate contains a constraint that is not supported and the certificate that is being verified does not contain the appropriate field, Cisco ISE rejects the certificate because it cannot verify unsupported constraints.

The following is an example of the name constraints definition within the trusted certificate:


X509v3 Name Constraints: critical
                Permitted:
                  othername:<unsupported>
                  email:.abcde.at
                  email:.abcde.be
                  email:.abcde.bg
                  email:.abcde.by
                  DNS:.dir
                  DirName: DC = dir, DC = emea
                  DirName: C = AT, ST = EMEA, L = AT, O = ABCDE Group, OU = Domestic
                  DirName: C = BG, ST = EMEA, L = BG, O = ABCDE Group, OU = Domestic
                  DirName: C = BE, ST = EMEA, L = BN, O = ABCDE Group, OU = Domestic
                  DirName: C = CH, ST = EMEA, L = CH, O = ABCDE Group, OU = Service Z100
                  URI:.dir
                  IP:172.23.0.171/255.255.255.255
                Excluded:
                  DNS:.dir
                  URI:.dir

An acceptable client certificate subject that matches the above definition is as follows:


           Subject: DC=dir, DC=emea, OU=+DE, OU=OU-Administration, OU=Users, OU=X1, 			CN=cwinwell

View Trusted Certificates

The Trusted Certificates window lists all the trusted certificates that are available in Cisco ISE. To view the trusted certificates, you must be a Super Admin or System Admin.

Before you begin

To perform the following task, you must be a Super Admin or System Admin.

Procedure

Step 1	To view all the certificates, choose Administration > System > Certificates > Trusted Certificates. The Trusted Certificates window displayed, listing all the trusted certificates.
Step 2	Check the check box of the trusted certificate and click Edit, View, Export, or Delete to perform the required task.

Change the Status of a Certificate in Trusted Certificates Store

The status of a certificate must be enabled so that Cisco ISE can use the certificate for establishing trust. When a certificate is imported into the Trusted Certificates store, it is automatically enabled.

Add a Certificate to Trusted Certificates Store

The Trusted Certificate store window allows you to add CA certificates to Cisco ISE.

Before you begin

To perform the following task, you must be a Super Admin or System Admin.
The certificate that you want to add must be in the file system of the computer where your browser is running. The certificate must be in PEM or DER format.
To use the certificate for Admin or EAP authentication, define the basic constraints in the certificate and set the CA flag to true.

Edit a Trusted Certificate

After you add a certificate to the Trusted Certificates store, you can further edit it by using the Edit options.

Before you begin

To perform the following task, you must be a Super Admin or System Admin.

Procedure

Step 1	Administration > System > Certificates > Trusted Certificates.
Step 2	Check the check box next to the certificate that you want to edit, and click Edit.
Step 3	(Optional) Enter a name for the certificate in the Friendly Name field. If you do not specify a friendly name, a default name is generated in the following format: common-name#issuer#nnnnn
Step 4	Define the usage of the certificate by checking the necessary check boxes in the Trusted For area.
Step 5	(Optional) Enter a description for the certificate in the Description field.
Step 6	Click Save.

Delete a Trusted Certificate

You can delete trusted certificates that you no longer need. However, you must not delete Cisco ISE internal CA certificates. Cisco ISE internal CA certificates can be deleted only when you replace the Cisco ISE root certificate chain for the entire deployment.

Procedure

Step 1

Choose Administration > System > Certificates > Trusted Certificates.

Step 2

Check the check boxes next to the certificates that you want to delete, and click Delete.

A warning message is displayed. To delete the Cisco ISE Internal CA certificates, click one of the following options:

Delete: To delete the Cisco ISE internal CA certificates. All endpoint certificates that are signed by the Cisco ISE internal CA become invalid and the endpoints cannot join the network. To allow the endpoints on the network again, import the same Cisco ISE internal CA certificates into the Trusted Certificates store.
Delete & Revoke: Deletes and revokes the Cisco ISE internal CA certificates. All endpoint certificates that are signed by the Cisco ISE internal CA become invalid and the endpoints cannot get on to the network. This operation cannot be undone. You must replace the Cisco ISE root certificate chain for the entire deployment.

Step 3

Click Yes to delete the certificate.

Export a Certificate from Trusted Certificates Store

Before you begin

To perform the following task, you must be a Super Admin or System Admin.

Note

If you export certificates from the internal CA and plan to use the exported certificates to restore from backup, use the CLI command application configure ise. See Export Cisco ISE CA Certificates and Keys.

Procedure

Step 1	Choose Administration > System > Certificates > Trusted Certificates.
Step 2	Check the check box next to the certificate that you want to export, and click Export. You can export only one certificate at a time.
Step 3	Save the PEM file to the file system that is running your client browser.

Import a Root Certificate to Trusted Certificate Store

While importing the root CA and intermediate CA certificates, specify the services for which the trusted CA certificates are to be used.

Before you begin

You must have the root certificate and other intermediate certificates from the CA that signed your certificate signing requests and returned the digitally signed CA certificates.

Procedure

Step 1	Choose Administration > System > Certificates > Trusted Certificates.
Step 2	Click Import.
Step 3	In the Import a new Certificate into the Certificate Store window that is displayed, click Choose File to select the root CA certificate signed and returned by your CA.
Step 4	Enter a Friendly Name. If you do not enter a Friendly Name, Cisco ISE autopopulates this field with a name of the format common-name#issuer#nnnnn, where nnnnn is a unique number. You can also edit the certificate at a later time to change the Friendly Name.
Step 5	Check the check boxes next to the services for which you want to use this trusted certificate.
Step 6	(Optional) In the Description field, enter a description for your certificate.
Step 7	Click Submit.

What to do next

Import the intermediate CA certificates into the Trusted Certificates store (if applicable).

Trusted Certificate Import Settings

Table 1. Trusted Certificate Import Settings
Field Name	Description
Certificate File	Click Browse to choose the certificate file from the computer that is running the browser.
Friendly Name	Enter a friendly name for the certificate. If you do not specify a name, Cisco ISE automatically creates a name in the format <common name># <issuer># <nnnnn>, where <nnnnn> is a unique five-digit number.
Trust for authentication within ISE	Check the check box if you want this certificate to be used to verify server certificates (from other ISE nodes or LDAP servers).
Trust for client authentication and Syslog	(Applicable only if you check the Trust for authentication within ISE check box) Check the check box if you want this certificate to be used to: Authenticate endpoints that connect to ISE using the EAP protocol Trust a Syslog server
Trust for authentication of Cisco Services	Check this check box if you want this certificate to be used to trust external Cisco services such as the feed service.
Validate Certificate Extensions	(Only if you check both the Trust for client authentication and Enable Validation of Certificate Extensions options) Ensure that the “keyUsage” extension is present and the “keyCertSign” bit is set, and that the basic constraints extension is present with the CA flag set to true.
Description	Enter an optional description.

Certificate Chain Import

You can import multiple certificates from a single file that contains a certificate chain received from a Certificate store. All certificates in the file must be in the PEM format, and the certificates must be arranged in the following order:

The last certificate in the file must be the client or server certificate issued by the CA.
All preceding certificates must be the root CA certificate plus any intermediate CA certificates in the signing chain for the issued certificate.

Importing a certificate chain is a two-step process:

Import the certificate chain file into the Trusted Certificate store in the Cisco ISE administration portal. This operation imports all certificates from the file except the last one into the Trusted Certificates store.
Import the certificate chain file using the Bind a CA-Signed Certificate operation. This operation imports the last certificate from the file as a local certificate.

Certificate-Signing Requests

For a CA to issue a signed certificate, you must create a certificate signing request and submit it to the CA.

The list of certificate-signing requests that you have created is available in the Certificate-Signing Requests window. ChooseAdministration > System > Certificates > Certificate-Signing Requests. To obtain signatures from a CA, you must export the certificate-signing request and then send the certificates to the CA. The CA signs and returns your certificates.

You can manage the certificates centrally from the Cisco ISE administration portal. You can create certificate-signing requests for all the nodes in your deployment and export them. Then, you should submit the certificate-signing requests to a CA, obtain the signed certificates from the CA, import the root and intermediary CA certificates given by the CA into the Trusted Certificates store, and bind the CA-signed certificates to the certificate-signing requests.

Create a Certificate-Signing Request and Submit it to a Certificate Authority

You can generate a certificate-signing request to obtain a CA-signed certificate for the nodes in your deployment. You can generate the certificate-signing request for a specific node in the deployment or for all the nodes in your deployment.

Procedure

Step 1	Choose Administration > System > Certificates > Certificate-Signing Requests.
Step 2	Click Generate Certificate-Signing Requests (CSR) to generate the certificate-signing request.
Step 3	Enter the values for generating a certificate-signing request. See Trusted Certificate Settings for information on each of the fields in the window displayed.
Step 4	(Optional) Check the check box of the signing request that you want to download and and click Export to download the request.
Step 5	Copy all the text from “-----BEGIN CERTIFICATE REQUEST-----” through “-----END CERTIFICATE REQUEST-----.” and paste the contents of the request in the certificate request of the chosen CA.
Step 6	Download the signed certificate. Some CAs might email the signed certificate to you. The signed certificate is in the form of a .zip file that contains the newly issued certificate and the public signing certificates of the CA that you must add to the Cisco ISE trusted certificates store. The digitally-signed CA certificate, root CA certificate, and other intermediate CA certificate (if applicable) can be downloaded to the local system running your client browser.

Bind a CA-Signed Certificate to a Certificate Signing Request

After the CA returns the digitally signed certificate, you must bind it to the certificate-signing request. You can perform the bind operation for all the nodes in your deployment, from the Cisco ISE administration portal.

Before you begin

You must have the digitally signed certificate, and the relevant root intermediate CA certificates sent by the CA.
Import the relevant root and intermediate CA certificates to the Trusted Certificates store (Administration > System > Certificates > Trusted Certificates).

Procedure

Step 1

Choose Administration > System > Certificates > Certificate-Signing Requests.

Step 2

Check the check box next to the certificate signing request you must bind with the CA-signed certificate.

Step 3

Click Bind.

Step 4

In the Bind CA Signed Certificate window displayed, click Browse to choose the CA-signed certificate.

Step 5

Enter a value in the Friendly Name field.

Step 6

Check the Validate Certificate Extensions check box if you want Cisco ISE to validate certificate extensions.

If you enable the Validate Certificate Extensions option, and the certificate that you import contains a basic constraints extension with the CA flag set to True, ensure that the key usage extension is present, and that the keyEncipherment bit or the keyAgreement bit, or both, are also set.

Note

Cisco ISE requires EAP-TLS client certificates to have digital signature key usage extension.

Step 7

(Optional) Check the services for which this certificate will be used in the Usage area.

This information is autopopulated if you have enabled the Usage option while generating the certificate signing request. If you do not want to specify the usage at the time of binding the certificate, uncheck the Usage option. You can also choose to edit the certificate at a later time to specify the usage.

Changing the Admin usage certificate on a primary PAN restarts the services on all the other nodes. The system restarts one node at a time, after the primary PAN restarts.

Step 8

Click Submit to bind the certificate-signing request with the CA-signed certificate.

If this certificate is marked for Cisco ISE internode communication usage, the application server on the Cisco ISE node restarts.

Repeat this process to bind the certificate-signing request with the CA-signed certificate on the other nodes in the deployment.

What to do next

Import a Root Certificate to Trusted Certificate Store

Export a Certificate-Signing Request

Before you begin

To perform the following task, you must be a Super Admin or System Admin.

Procedure

Step 1	Choose Administration > System > Certificates > Certificate-Signing Requests.
Step 2	Check the check box next to the certificates that you want to export, and click Export.
Step 3	Click OK to save the file to the file system that is running the client browser.
Step 4	The certificate-signing request is downloaded to your local file system.

Set Up Certificates for Portal Use

Note

Cisco ISE presents the Portal certificate on TCP port 8443 (or the port that you have configured for portal use).

Procedure

Step 1

Create a Certificate-Signing Request and Submit it to a Certificate Authority.

You must choose a Certificate Group Tag that you have already defined or create a new one for the portal. For example, mydevicesportal.

Step 2

Import a Root Certificate to Trusted Certificate Store.

Step 3

Bind a CA-Signed Certificate to a Certificate Signing Request.

Reassign Default Portal Certificate Group Tag to CA-Signed Certificate

By default, all Cisco ISE portals use the self-signed certificate. If you want to use a CA-signed certificate for portals, you can assign the default portal certificate group tag to a CA-signed certificate. You can use an existing CA-signed certificate or generate a CSR and obtain a new CA-signed certificate for portal use. You can reassign any portal group tag from one certificate to another.

Note

When you edit an existing certificate, if the portal tag (guest) that is associated with the certificate is already in use by any of the portals, then you cannot reassign the default portal certificate group tag or any other portal group tag to this certificate. The system displays the list of portals that use the "guest" portal tag.

The following procedure describes how to reassign the default portal certificate group tag to a CA-signed certificate.

Procedure

Step 1	Choose Administration > System > Certificates > System Certificates. Hover the mouse over the i icon next to the Default Portal Certificate Group tag to view the list of portals that use this tag. You can also view the ISE nodes in the deployment that have portal certificates which are assigned this tag.
Step 2	Check the check box next to the CA-signed certificate that you want to use for portals, and click Edit. Be sure to choose a CA-signed certificate that is not in use by any of the portals.
Step 3	Under the Usage area, check the Portal check box and choose the Default Portal Certificate Group Tag.
Step 4	Click Save. A warning message appears.
Step 5	Click Yes to reassign the default portal certificate group tag to the CA-signed certificate.

Associate Portal Certificate Tag Before You Register a Node

If you use the "Default Portal Certificate Group" tag for all the portals in your deployment, before you register a new ISE node, ensure that you import the relevant CA-signed certificate, choose "Portal" as a service, and associate the "Default Portal Certificate Group" tag with this certificate.

When you add a new node to a deployment, the default self-signed certificate is associated with the "Default Portal Certificate Group" tag and the portals are configured to use this tag.

After you register a new node, you cannot change the Certificate Group tag association. Therefore, before you register the node to the deployment, you must do the following:

Procedure

Step 1

Create a self-signed certificate, choose "Portal" as a service, and assign a different certificate group tag (for example, tempportaltag).

Step 2

Change the portal configuration to use the newly created certificate group tag (tempportaltag).

Step 3

Edit the default self-signed certificate and remove the Portal role.

This option removes the Default Portal Certificate Group tag association with the default self-signed certificate.

Step 4

Do one of the following:

Option

Description

Generate a CSR

When you generate the CSR:

Choose "Portal" as a service for which you will use this certificate and associate the "Default Portal Certificate Group" tag.
Send the CSR to a CA and obtain the signed certificate.
Import the root and any other intermediate certificates of the CA that signed your certificate in to the Trusted Certificates store.
Bind the CA-signed certificate with the CSR.

Import the private key and the CA-signed certificate

When you import the CA-signed certificate:

Choose "Portal" as a service for which you will use this certificate and associate the "Default Portal Certificate Group" tag.
Import the root and any other intermediate certificates of the CA that signed your certificate in to the Trusted Certificates store.

Edit an existing CA-signed certificate.

When you edit the existing CA-signed certificate:

Choose "Portal" as a service for which you will use this certificate and associate the "Default Portal Certificate Group" tag.

Step 5

The portal configuration in the deployment is configured to the "Default Portal Certificate Group" tag and the portals are configured to use the CA-signed certificate associated with the "Default Portal Certificate Group" tag on the new node.

User and Endpoint Certificate Renewal

By default, Cisco ISE rejects a request that comes from a device whose certificate has expired. However, you can change this default behavior and configure ISE to process such requests and prompt the user to renew the certificate.

If you choose to allow the user to renew the certificate, Cisco recommends that you configure an authorization policy rule which checks if the certificate has been renewed before processing the request any further. Processing a request from a device whose certificate has expired may pose a potential security threat. Hence, you must configure appropriate authorization profiles and rules to ensure that your organization’s security is not compromised.

Some devices allow you to renew the certificates before and after their expiry. But on Windows devices, you can renew the certificates only before it expires. Apple iOS, Mac OSX, and Android devices allow you to renew the certificates before or after their expiry.

Dictionary Attributes Used in Policy Conditions for Certificate Renewal

Cisco ISE certificate dictionary contains the following attributes that are used in policy conditions to allow a user to renew the certificate:

Days to Expiry: This attribute provides the number of days for which the certificate is valid. You can use this attribute to create a condition that can be used in authorization policy. This attribute can take a value from 0 to 15. A value of 0 indicates that the certificate has already expired. A value of 1 indicates that the certificate has less than 1 day before it expires.
Is Expired: This Boolean attribute indicates whether a certificate has expired or not. If you want to allow certificate renewal only when the certificate is near expiry and not after it has expired, use this attribute in authorization policy condition.

Authorization Policy Condition for Certificate Renewal

You can use the CertRenewalRequired simple condition (available by default) in authorization policy to ensure that a certificate (expired or about to expire) is renewed before Cisco ISE processes the request further.

CWA Redirect to a Renew Certificate

If a user certificate is revoked before its expiry, Cisco ISE checks the CRL published by the CA and rejects the authentication request. In case, if a revoked certificate has expired, the CA may not publish this certificate in its CRL. In this scenario, it is possible for Cisco ISE to renew a certificate that has been revoked. To avoid this, before you renew a certificate, ensure that the request gets redirected to Central Web Authentication (CWA) for a full authentication. You must create an authorization profile to redirect the user for CWA.

Configure Cisco ISE to Allow Users to a Renew Certificate

You must complete the tasks listed in this procedure to configure Cisco ISE to allow users to renew certificates.

Before you begin

Configure a limited access ACL on the WLC to redirect a CWA request.

Procedure

Step 1	Update the Allowed Protocol Configuration
Step 2	Create an Authorization Policy Profile for CWA Redirection
Step 3	Create an Authorization Policy Rule to Renew a Certificate
Step 4	Enable BYOD Settings in Guest Portal

Update the Allowed Protocol Configuration

Procedure

Step 1

Choose Policy > Policy Elements > Results > Authentication > Allowed Protocols > Default Network Access.

Step 2

Check the Allow Authentication of expired certificates to allow certificate renewal in Authorization Policy check box under the EAP-TLS protocol and EAP-TLS inner methods for PEAP and EAP-FAST protocols.

Requests that use the EAP-TLS protocol will go through the NSP flow.

For PEAP and EAP-FAST protocols, you must manually configure Cisco AnyConnect for Cisco ISE to process the request.

Step 3

Click Submit.

What to do next

Create an Authorization Policy Profile for CWA Redirection

Before you begin

Ensure that you have configured a limited access ACL on the WLC.

Procedure

Step 1	Choose Policy > Policy Elements > Results > Authorization > Authorization Profiles.
Step 2	Click Add.
Step 3	Enter a name for the authorization profile. For example, CertRenewal_CWA.
Step 4	Check the Web Redirection (CWA, DRW, MDM, NSP, CPP) check box in the Common Tasks area.
Step 5	Choose Centralized Web Auth from the drop-down list and the limited access ACL.
Step 6	Check the Display Certificates Renewal Message check box. The URL-redirect attribute value changes and includes the number of days for which the certificate is valid.
Step 7	Click Submit.

Note

If you have configured the following Device Registration WebAuth (DRW) policies for wireless devices in Cisco ISE 1.2:

DRW-Redirect policy with Condition = (Wireless_MAB AND Network Access:UseCase EQUALS HostLookup) and Profile = Wireless-drw-redirect
DRW-Allow policy with Condition = (Wireless_MAB AND Network Access:UseCase EQUALS HostLookup) and Profile = Wireless-Permit

After upgrading to ISE 1.3 or above version, you must update the DRW-Allow policy condition as follows:

Condition = (Wireless_MAB AND Network Access:UseCase EQUALS Guest Flow) and Profile = Wireless-Permit

What to do next

Create an Authorization Policy Rule to Renew a Certificate

Before you begin

Ensure that you have created an authorization profile for central web authentication redirection.

Enable Policy Sets on Administration > System > Settings > Policy Settings.

Procedure

Step 1	Choose Work Centers > Device Administration > Policy Sets.
Step 2	Click Create Above.
Step 3	Enter a name for the new rule.
Step 4	Choose the following simple condition and result: If CertRenewalRequired EQUALS True, then choose the authorization profile that you created earlier (CertRenewal_CWA) for the permission.
Step 5	Click Save.

What to do next

When you access the corporate network with a device whose certificate has expired, click Renew to reconfigure your device.

Enable BYOD Settings in Guest Portal

For a user to be able to renew a personal device certificate, you must enable the BYOD settings in the chosen guest portal.

Procedure

Step 1

Choose Work Centers > Guest Access > Portals & Components > Guest Portals.

Select the chosen CWA portal and click Edit.

Step 2

From BYOD Settings, check the Allow employees to use personal devices on the network check box.

Step 3

Click Save.

Certificate Renewal Fails for Apple iOS Devices

When you use ISE to renew the endpoint certificates on Apple iOS devices, you might see a “Profiled Failed to Install” error message. This error message appears if the expiring or expired network profiles were signed by a different Admin HTTPS certificate than the one that is used in processing the renewal, either on the same Policy Service Node (PSN) or on another PSN.

As a workaround, use a multi-domain SSL certificate, which is commonly referred to as Unified Communications Certificate (UCC), or a wildcard certificate for Admin HTTPS on all PSNs in the deployment.

Cisco ISE CA Service

Certificates can be self-signed or digitally signed by an external Certificate Authority (CA). The Cisco ISE Internal Certificate Authority (ISE CA) issues and manages digital certificates for endpoints from a centralized console to allow employees to use their personal devices on the company's network. A CA-signed digital certificate is considered industry standard and more secure. The Primary PAN is the Root CA. The Policy Service Nodes (PSNs) are subordinate CAs to the Primary PAN (SCEP RA). The ISE CA offers the following functionalities:

Certificate Issuance: Validates and signs Certificate Signing Requests (CSRs) for endpoints that connect to your network.
Key Management: Generates and securely stores keys and certificates on both PAN and PSN nodes.
Certificate Storage: Stores certificates issued to users and devices.
Online Certificate Status Protocol (OCSP) Support: Provides an OCSP responder to check for the validity of certificates.

When a CA Service is disabled on the primary administrative node, the CA service is still seen as running on the secondary administration node's CLI. Ideally, the CA service should be seen as disabled. This is a known Cisco ISE issue.

Cisco ISE CA Certificates Provisioned on Administration and Policy Service Nodes

After installation, a Cisco ISE node is provisioned with a Root CA certificate, and a Node CA certificate to manage certificates for endpoints.

Figure 2. Cisco ISE CA Certificates Provisioned on a Standalone Node

When you set up a deployment, the node that you designate as the Primary Administration Node (PAN) becomes the Root CA. The PAN has a Root CA certificate and a Node CA certificate that is signed by the Root CA.

When you register a Secondary Administration Node to the PAN, a Node CA certificate is generated and is signed by the Root CA on the Primary Administration Node.

Any Policy Service Node (PSN) that you register with the PAN is provisioned an Endpoint CA and an OCSP certificate signed by the Node CA of the PAN. The Policy Service Nodes (PSNs) are subordinate CAs to the PAN. When you use the ISE CA, the Endpoint CA on the PSN issues the certificates to the endpoints that access your network.

Figure 3. Cisco ISE CA Certificates Provisioned on Administration and Policy Service Nodes in a Deployment

Cisco ISE CA Chain Regeneration

When you regenerate the Cisco ISE CA chain, all the certificates including the Root CA, Node CA, and Endpoint CA certificates are regenerated. You must regenerate the ISE CA chain when you change the domain name or hostname of your PAN or PSN. When you upgrade from earlier releases to Release 2.0 or later, we recommend that you regenerate the ISE CA chain to move from the two root hierarchy to a single root hierarchy.

Elliptical Curve Cryptography Certificates Support

Cisco ISE CA service supports certificates that are based on Elliptical Curve Cryptography (ECC) algorithms. ECC offers more security and better performance than other cryptographic algorithms even when using a much smaller key size.

The following table compares the key sizes of ECC and RSA and security strength.

ECC Key Size (in bits)	RSA Key Size (in bits)
160	1024
224	2048
256	3072
384	7680
521	15360

Because of the smaller key size, encryption is quicker.

Cisco ISE supports the following ECC curve types. The higher the curve type or key size, the greater is the security.

P-192
P-256
P-384
P-521

ISE does not support explicit parameters in the EC part of a certificate. If you try to import a certificate with explicit parameters, you get the error: Validation of certificate failed: Only named ECParameters supported.

Cisco ISE CA service supports ECC certificates for devices connecting through the BYOD flow. You can also generate ECC certificates from the Certificate Provisioning Portal.

Note

The following table lists the operating systems and versions that support ECC along with the supported curve types. If your devices are not running a supported operating system or on a supported version, you can use RSA-based certificates instead.

Operating System

Supported Versions

Supported Curve Types

Windows

8 and later

P-256, P-384, and P-521

Android

4.4 and later

Note

Android 6.0 requires May 2016 patch to support ECC certificates.

All curve types (except Android 6.0, which does not support the P-192 curve type).

Windows 7 and Apple iOS do not natively support ECC for authentication over EAP-TLS. This release of Cisco ISE does not support the use of ECC certificates on MAC OS X devices.

If the BYOD flow with Enrollment over Secure Transport (EST) protocol is not working properly, check the following:

Certificate Services Endpoint Sub CA certificate chain is complete. To check whether the certificate chain is complete:
1. Choose Administration > System > Certificates > Certificate Authority > Certificate Authority Certificates.
2. Check the check box next to the certificate that you want to check and click View.
Ensure that the CA and EST services are up and running. If the services are not running, go to Administration > System > Certificates > Certificate Authority > Internal CA Settings to enable the CA service.
If you have upgraded to Cisco ISE 2.x from an ISE version prior to 2.0, replace the ISE Root CA certificate chain after the upgrade. To do this:
1. Choose Administration > System > Certificates > Certificate Management > Certificate Signing Requests.
2. Click Generate Certificate Signing Requests (CSR).
3. Choose ISE Root CA from one or more Certificates will be used for drop-down list.
4. Click Replace ISE Root CA Certificate Chain.

Note

This release of Cisco ISE does not support EST clients to authenticate directly against the EST Server residing within Cisco ISE.

While on-boarding an Android or a Windows endpoint, ISE triggers an EST flow if the request is for an ECC-based certificate.

Cisco ISE Certificate Authority Certificates

The Certificate Authority (CA) Certificates page lists all the certificates related to the internal Cisco ISE CA. In previous releases, these CA certificates were present in the Trusted Certificates store and are now moved to the CA Certificates page. These certificates are listed node wise in this page. You can expand a node to view all the ISE CA certificates of that particular node. The Primary and Secondary Administration nodes have the root CA, node CA, subordinate CA, and OCSP responder certificates. The other nodes in the deployment have the endpoint subordinate CA and OCSP certificates.

When you enable the Cisco ISE CA service, these certificates are generated and installed on all the nodes automatically. Also, when you replace the entire ISE Root CA Chain, these certificates are regenerated and installed on all the nodes automatically. There is no manual intervention required.

The Cisco ISE CA certificates follow the following naming convention: Certificate Services <Endpoint Sub CA/Node CA/Root CA/OCSP Responder>-<node_hostname>#certificate_number.

From the CA Certificates page, you can edit, import, export, delete, and view the Cisco ISE CA certificates.

Edit a Cisco ISE CA Certificate

After you add a certificate to the Cisco ISE CA Certificates Store, you can further edit it by using the edit settings.

Before you begin

To perform the following task, you must be a Super Admin or System Admin.

Procedure

Step 1	Choose Administration > System > Certificates > Certificate Authority > Certificate Authority Certificates..
Step 2	In the ISE-PIC GUI, click the Menu icon () and choose .
Step 3	Check the check box next to the certificate that you want to edit, and click Edit.
Step 4	Modify the editable fields as required. See Trusted Certificate Settings for a description of the fields.
Step 5	Click Save to save the changes you have made to the certificate store.

Export a Cisco ISE CA Certificate

To export the Cisco ISE root CA and node CA certificates:

Before you begin

To perform the following task, you must be a Super Admin or System Admin.

Procedure

Step 1	Choose Administration > System > Certificates > Certificate Authority > Certificate Authority Certificates.
Step 2	In the ISE-PIC GUI, click the Menu icon () and choose .
Step 3	Check the check box next to the certificate that you want to export, and click Export. You can export only one certificate at a time.
Step 4	Save the privacy-enhanced mail file to the file system that is running your client browser.

Import a Cisco ISE CA Certificate

If an endpoint tries to authenticate to your network using a certificate issued by Cisco ISE CA from another deployment, you must import the Cisco ISE root CA, node CA, and endpoint sub CA certificates from that deployment in to the Cisco ISE Trusted Certificates store.

Before you begin

To perform the following task, you must be a Super Admin or System Admin.
Export the ISE root CA, node CA, and endpoint sub CA certificates from the deployment where the endpoint certificate is signed and store it on the file system of the computer where your browser is running.

Procedure

Step 1	Log in to the Admin Portal of the deployment where the endpoint is getting authenticated.
Step 2	Choose Administration > System > Certificates > Trusted Certificates.
Step 3	Click Import.
Step 4	Configure the field values as necessary. See Trusted Certificate Import Settings for more information. If client certificate-based authentication is enabled, then Cisco ISE will restart the application server on each node in your deployment, starting with the application server on the PAN and followed, one-by-one, by each additional node.

Certificate Templates

Certificate templates contain properties that are common to all certificates issued by the Certificate Authority (CA) based on that template. The certificate template defines the Subject, Subject Alternative Name (SAN), key type, key size, SCEP RA profile that must be used, validity period of the certificate, and the extended key usage (EKU) that specifies whether the certificate has to be used for client or server authentication or both. The internal Cisco ISE CA (ISE CA) uses a certificate template to issue certificates based on that template.

Cisco ISE comes with the following default certificate templates for the ISE CA. You can create additional certificate templates, if needed. The default certificate templates are:

CA_SERVICE_Certificate_Template—For other network services that use Cisco ISE as the Certificate Authority. For example, use this certificate template while configuring ISE to issue certificates for ASA VPN users. You can modify only the validity period in this certificate template.
EAP_Authentication_Certificate_Template—For EAP authentication.
pxGrid_Certificate_Template—For the pxGrid controller while generating the certificate from the Certificate Provisioning Portal.

Certificate Template Name Extension

The Cisco ISE Internal CA includes an extension to represent the certificate template that was used to create the endpoint certificate. All endpoint certificates issued by the internal CA contain a certificate template name extension. This extension represents the certificate template that was used to create that endpoint certificate. The extension ID is 1.3.6.1.4.1.9.21.2.5. You can use the CERTIFICATE: Template Name attribute in authorization policy conditions and assign appropriate access privileges based on the results of the evaluation.

Use Certificate Template Name in Authorization Policy Conditions

You can use the certificate template name extension in authorization policy rules.

Procedure

Step 1

Choose Policy > Policy Sets, and expand the Default policy set to view the authorization policy rules.

Step 2

Add a new rule or edit an existing rule. This example describes editing the Compliant_Device_Access rule:

Edit the Compliant_Device_Access rule.
Choose Add Attribute/Value.
From Dictionaries, choose the CERTIFICATE: Template Name attribute and Equals operator.
Enter the value of the certificate template name. For example, EAP_Authentication_Certificate_Template.

Step 3

Click Save.

Deploy Cisco ISE CA Certificates for pxGrid Controller

Cisco ISE CA provides a certificate template for the pxGrid controller to generate a certificate from the Certificate Provisioning Portal.

Before you begin

Generate a certificate signing request (CSR) for the pxGrid client and copy the contents of the CSR in to the clipboard.

Procedure

Step 1

Create a network access user account (Administration > Identity Management > Identities > Users > Add).

Make note of the user group to which the user is assigned.

Step 2

Edit the Certificate Provisioning Portal Settings (Administration > Device Portal Management > Certificate Provisioning).

Select the certificate provisioning portal and click Edit.
Click the Portal Settings drop-down list. From the Configure authorized groups Available list, select the user group to which the network access user belongs to and move it to Chosen list.
Click the Certificate Provisioning Portal Settings drop-down list. Choose the pxGrid_Certificate_Template. See Portal Settings for Certificate Provisioning Portal for more information.
Save the portal settings.

Step 3

Launch the Certificate Provisioning Portal. Click the Portal Test URL link.

Log in to the Certificate Provisioning Portal using the user account created in step 1.
Accept the AUP and click Continue.
From the I want to drop-down list, choose Generate a single certificate (with certificate signing request).
In the Certificate Signing Request Details field, paste the contents of the CSR from the clipboard.

From the Certificate Download Format drop-down list, choose PKCS8 format.

Note

If you choose the PKCS12 format, you must convert the single certificate file in to separate certificate and key files. The certificate and key files must be in binary DER encoded or PEM format before you can import them in to Cisco ISE.

From the Choose Certificate Template drop-down list, choose pxGrid_Certificate_Template.
Enter a certificate password.
Click Generate.

The certificate is generated.
Export the certificate.

The certificate along with the certificate chain is exported.

Step 4

Import the Cisco ISE CA chain in to the Trusted Certificates store in the pxGrid client.

Simple Certificate Enrollment Protocol Profiles

To help enable certificate provisioning functions for the variety of mobile devices that users can register on the network, Cisco ISE enables you to configure one or more Simple Certificate Enrollment Protocol (SCEP) Certificate Authority (CA) profiles (called as Cisco ISE External CA Settings) to point Cisco ISE to multiple CA locations. The benefit of allowing for multiple profiles is to help ensure high availability and perform load balancing across the CA locations that you specify. If a request to a particular SCEP CA goes unanswered three consecutive times, Cisco ISE declares that particular server unavailable and automatically moves to the CA with the next lowest known load and response times, then it begins periodic polling until the server comes back online.

For details on how to set up your Microsoft SCEP server to interoperate with Cisco ISE, see

http://www.cisco.com/en/US/solutions/collateral/ns340/ns414/ns742/ns744/docs/howto_60_byod_certificates.pdf.

Issued Certificates

The Admin portal lists all the certificates issued by the internal ISE CA to endpoints (Administration > System > Certificates > Endpoint Certificates). The Issued Certificates page provides you an at-a-glance view of the certificate status. You can mouse over the Status column to find out the reason for revocation if a certificate has been revoked. You can mouse over the Certificate Template column to view additional details such as Key Type, Key Size or Curve Type, Subject, Subject Alternative Name (SAN), and Validity of the certificate. You can click on the endpoint certificate to view the certificate.

All certificates issued by the ISE CA (certificates automatically provisioned through the BYOD flow and certificates obtained from the Certificate Provisioning portal) are listed in the Endpoint Certificates page. You can manage these certificates from this page.

For example, if you want to view the certificates issued to user7, enter user7 in the text box that appears below the Friendly Name field. All the certificates issued by Cisco ISE to this user appear. Remove the search term from the text box to cancel the filter. You can also use the Advanced Filter option to view records based on various search criteria.

This Endpoint Certificates page also provides you the option to revoke an endpoint certificate, if necessary.

The Certificate Management Overview page displays the total number of endpoint certificates issued by each PSN node in your deployment. You can also view the total number of revoked certificates per node and the total number of certificates that have failed. You can filter the data on this page based on any of the attributes.

Note

pxGrid certificates are not listed in the Issued Certificates page.

Backup and Restoration of Cisco ISE CA Certificates and Keys

You must back up the Cisco ISE CA certificates and keys securely to be able to restore them back on a Secondary Administration Node in case of a PAN failure and you want to promote the Secondary Administration Node to function as the root CA or intermediate CA of an external PKI. The Cisco ISE configuration backup does not include the CA certificates and keys. Instead, you should use the Command Line Interface (CLI) to export the CA certificates and keys to a repository and to import them. The application configure ise command now includes export and import options to backup and restore CA certificates and keys.

The following certificates from the Trusted Certificates Store are restored on the Secondary Administration Node:

Cisco ISE Root CA certificate
Cisco ISE Sub CA certificate
Cisco ISE Endpoint RA certificate
Cisco ISE OCSP Responder certificate

You must back up and restore Cisco ISE CA certificates and keys when you:

Have a Secondary Administration Node in the deployment
Replace the entire Cisco ISE CA root chain
Configure Cisco ISE root CA to act as a subordinate CA of an external PKI
Upgrade from Release 1.2 to a later release
Restore data from a configuration backup. In this case, you must first regenerate the Cisco ISE CA root chain and then back up and restore the ISE CA certificates and keys.

Export Cisco ISE CA Certificates and Keys

You must export the CA certificates and keys from the PAN to import them on the Secondary Administration Node. This option enables the Secondary Administration Node to issue and manage certificates for endpoints when the PAN is down and you promote the Secondary Administration Node to be the PAN.

Before you begin

Ensure that you have created a repository to store the CA certificates and keys.

Procedure

Step 1	Enter application configure ise command from the Cisco ISE CLI.
Step 2	Enter 7 to export the certificates and keys.
Step 3	Enter the repository name.
Step 4	Enter an encryption key. A success message appears with the list of certificates that were exported, along with the subject, issuer, and serial number. Example: The following 4 CA key pairs were exported to repository 'sftp' at 'ise_ca_key_pairs_of_ise-vm1': Subject:CN=Cisco ISE Self-Signed CA of ise-vm1 Issuer:CN=Cisco ISE Self-Signed CA of ise-vm1 Serial#:0x621867df-568341cd-944cc77f-c9820765 Subject:CN=Cisco ISE Endpoint CA of ise-vm1 Issuer:CN=Cisco ISE Self-Signed CA of ise-vm1 Serial#:0x7027269d-d80a406d-831d5c26-f5e105fa Subject:CN=Cisco ISE Endpoint RA of ise-vm1 Issuer:CN=Cisco ISE Endpoint CA of ise-vm1 Serial#:0x1a65ec14-4f284da7-9532f0a0-8ae0e5c2 Subject:CN=Cisco ISE OCSP Responder Certificate of ise-vm1 Issuer:CN=Cisco ISE Self-Signed CA of ise-vm1 Serial#:0x6f6d4097-21f74c4d-8832ba95-4c320fb1 ISE CA keys export completed successfully

Import Cisco ISE CA Certificates and Keys

After you register the Secondary Administration Node, you must export the CA certificates and keys from the PAN and import them in to the Secondary Administration Node.

Procedure

Step 1

Enter application configure ise command from the Cisco ISE CLI.

Step 2

Enter 8 to import the CA certificates and keys.

Step 3

Enter the repository name.

Step 4

Enter the name of the file that you want to import. The file name should be in the format ise_ca_key_pairs_of_<vm hostname>.

Step 5

Enter the encryption key to decrypt the file.

A success message appears.

Example:

The following 4 CA key pairs were imported:
        Subject:CN=Cisco ISE Self-Signed CA of ise-vm1
        Issuer:CN=Cisco ISE Self-Signed CA of ise-vm1
        Serial#:0x21ce1000-8008472c-a6bc4fd9-272c8da4

        Subject:CN=Cisco ISE Endpoint CA of ise-vm1
        Issuer:CN=Cisco ISE Self-Signed CA of ise-vm1
        Serial#:0x05fa86d0-092542b4-8ff68ed4-f1964a56

        Subject:CN=Cisco ISE Endpoint RA of ise-vm1
        Issuer:CN=Cisco ISE Endpoint CA of ise-vm1
        Serial#:0x77932e02-e8c84b3d-b27e2f1c-e9f246ca

        Subject:CN=Cisco ISE OCSP Responder Certificate of ise-vm1
        Issuer:CN=Cisco ISE Self-Signed CA of ise-vm1
        Serial#:0x5082017f-330e412f-8d63305d-e13fd2a5

Stopping ISE Certificate Authority Service...
Starting ISE Certificate Authority Service...
ISE CA keys import completed successfully

Note

Encryption of exported keys file was introduced in Cisco ISE Release 2.6. The export of keys from Cisco ISE Release 2.4 and earlier versions and import of keys in Cisco ISE Release 2.6 and later versions will not be successful.

Generate Root CA and Subordinate CAs on the Primary PAN and PSN

When you set up the deployment, Cisco ISE generates a root CA on the primary PAN and subordinate CA certificates on the PSNs for the Cisco ISE CA service. However, when you change the domain name or the hostname of the primary PAN or PSN, you must regenerate root CA on the primary PAN and sub CAs on the PSNs respectively.

If you want to change the hostname on a PSN, instead of regenerating the root CA and subordinate CAs on the primary PAN and PSNs respectively, you can deregister the PSN before changing the hostname, and register it back. A new subordinate certificate gets provisioned automatically on the PSN.

Procedure

Step 1	Choose Administration > System > Certificates > Certificate Signing Requests
Step 2	Click Generate Certificate Signing Requests (CSR).
Step 3	Choose ISE Root CA from the Certificate(s) will be used for drop-down list.
Step 4	Click Replace ISE Root CA Certificate chain. The root CA and subordinate CA certificates get generated for all the nodes in your deployment.

What to do next

If you have a secondary PAN in the deployment, obtain a backup of the Cisco ISE CA certificates and keys from the primary PAN and restore it on the secondary PAN. This ensures that the secondary PAN can function as the root CA in case of a primary PAN failure and you promote the secondary PAN to be the primary PAN.

Configure Cisco ISE Root CA as Subordinate CA of an External PKI

If you want the root CA on the primary PAN to act as a subordinate CA of an external PKI, generate an ISE intermediate CA certificate signing request, send it to the external CA, obtain the root and CA-signed certificates, import the root CA certificate in to the Trusted Certificates Store, and bind the CA-signed certificate to the CSR. In this case, the external CA is the root CA, the Primary PAN is a subordinate CA of the external CA, and the PSNs are subordinate CAs of the primary PAN.

Procedure

Step 1	Choose Administration > System > Certificates > Certificate Signing Requests.
Step 2	Click Generate Certificate Signing Requests (CSR).
Step 3	Choose ISE Intermediate CA from the Certificate(s) will be used for drop-down list.
Step 4	Click Generate.
Step 5	Export the CSR, send it to the external CA, and obtain the CA-signed certificate.
Step 6	Import the root CA certificate from the external CA in to the Trusted Certificates store.
Step 7	Bind the CA-signed certificate with the CSR.

What to do next

If you have a secondary PAN in the deployment, obtain a backup of the Cisco ISE CA certificates and keys from the primary PAN and restore it on the secondary PAN. Server and root certificates are then automatically replicated in the secondary PAN. This ensures that the secondary PAN can function as subordinate CA of the external PKI in case of administration node failover.

Configure Cisco ISE to Use Certificates for Authenticating Personal Devices

You can configure Cisco ISE to issue and manage certificates for endpoints (personal devices) that connect to your network. You can use the internal Cisco ISE CA service to sign the certificate signing request from endpoints or forward the CSR to an external CA.

Before you begin

Obtain a backup of the Cisco ISE CA certificates and keys from the primary PAN and store them in a secure location for disaster recovery purposes.
If you have a secondary PAN in the deployment, back up the Cisco ISE CA certificates and keys from the primary PAN and restore them on the secondary PAN.

Procedure

Step 1	Add Users to Employee User Group. You can add users to the internal identity store or to an external identity store such as Microsoft Active Directory.
Step 2	Create a Certificate Authentication Profile for TLS-Based Authentication .
Step 3	Create an Identity Source Sequence for TLS-Based Authentication.
Step 4	Create a client provisioning policy: Configure Certificate Authority Settings Create a CA Template Create a Native Supplicant Profile to be Used in Client-Provisioning Policy Download Agent Resources from Cisco for Windows and MAC OS X Operating Systems Create Client-Provisioning Policy Rules for Apple iOS, Android, and MAC OS X Devices
Step 5	Configure the Dot1X Authentication Policy Rule for TLS-Based Authentication
Step 6	Configure authorization policy rules for TLS-based authentications. Create Authorization Profiles for Central Web Authentication and Supplicant-Provisioning Flows Create Authorization Policy Rules When you use ECDHE-RSA based certificates, while connecting to the wireless SSID from your personal device, you will be prompted to enter the password a second time.

Add Users to Employee User Group

The following procedure describes how to add users to the Employee user group in the Cisco ISE identity store. If you are using an external identity store, make sure that you have an Employee user group to which you can add users.

Procedure

Step 1	Choose Administration > Identity Management > Identities > Users.
Step 2	Click Add.
Step 3	Enter the user details.
Step 4	In the Passwords section, choose the Login Password and TACACS+ Enable Password to set the access level to a network device.
Step 5	Select Employee from the User Group drop-down list. All users who belong to the Employee user group share the same set of privileges.
Step 6	Click Submit.

What to do next

Create a Certificate Authentication Profile for TLS-Based Authentication

To use certificates for authenticating endpoints that connect to your network, you must define a certificate authentication profile in Cisco ISE or edit the default Preloaded_Certificate_Profile. The certificate authentication profile includes the certificate field that should be used as the principal username. For example, if the username is in the Common Name field, then you can define a certificate authentication profile with the Principal Username being the Subject - Common Name, which can be verified against the identity store.

Procedure

Step 1	Choose Administration > Identity Management > External Identity Sources > Certificate Authentication Profile.
Step 2	Enter a name for your certificate authentication profile. For example, CAP.
Step 3	Choose Subject - Common Name as the Principal Username X509 Attribute.
Step 4	Click Save.

What to do next

Create an Identity Source Sequence for TLS-Based Authentication

After you create a certificate authentication profile, you must add it to the identity source sequence so that Cisco ISE can obtain the attribute from the certificate and match it against the identity sources that you have defined in the identity source sequence.

Before you begin

Ensure that you have completed the following tasks:

Add users to the Employee user group.
Create a certificate authentication profile for certificate-based authentication.

Procedure

Step 1	Choose Administration > Identity Management > Identity Source Sequences.
Step 2	Click Add.
Step 3	Enter a name for the identity source sequence. For example, Dot1X.
Step 4	Check the Select Certificate Authentication Profile check box and select the certificate authentication profile that you created earlier, namely CAP.
Step 5	Move the identity source that contains your user information to the Selected list box in the Authentication Search List area. You can add additional identity sources and Cisco ISE searches these data stores sequentially until a match is found.
Step 6	Click the Treat as if the user was not found and proceed to the next store in the sequence radio button.
Step 7	Click Submit.

What to do next

Configure Certificate Authority Settings

You must configure the external CA settings if you are going to use an external CA for signing the CSRs. The external CA settings was known as the SCEP RA profile in previous releases of Cisco ISE. If you are using the Cisco ISE CA, then you do not have to explicitly configure the CA settings. You can review the Internal CA settings at Administration > System > Certificates > Internal CA Settings.

Once users’ devices receive their validated certificate, they reside on the device as described in the following table.

Table 2. Device Certificate Location

Device

Certificate Storage Location

Access Method

iPhone/iPad

Standard certificate store

Settings > General > Profile

Android

Encrypted certificate store

Invisible to end users.

Note

Certificates can be removed using Settings > Location & Security > Clear Storage.

Windows

Standard certificate store

Launch mmc.exe from the /cmd prompt or view in the certificate snap-in.

Mac

Standard certificate store

Application > Utilities > Keychain Access

Before you begin

If you are going to use an external Certificate Authority (CA) for signing the certificate signing request (CSR), then you must have the URL of the external CA.

Procedure

Step 1	Choose Administration > System > Certificates > External CA Settings.
Step 2	Click Add.
Step 3	Enter a name for the external CA setting. For example, EXTERNAL_SCEP.
Step 4	Enter the external CA server URL in the URL text box. Click Test Connection to check if the external CA is reachable. Click the + button to enter additional CA server URLs.
Step 5	Click Submit.

What to do next

Create a CA Template

The certificate template defines the SCEP RA profile that must be used (for the internal or external CA), Key Type, Key Size or Curve Type, Subject, Subject Alternative Name (SAN), validity period of the certificate, and the Extended Key Usage. This example assumes that you are going to use the internal Cisco ISE CA. For an external CA template, the validity period is determined by the external CA and you cannot specify it.

You can create a new CA template or edit the default certificate template, EAP_Authentication_Certificate_Template.

By default, the following CA templates are available in Cisco ISE:

CA_SERVICE_Certificate_Template—For other network services that use the ISE CA. For example, use this certificate template while configuring ISE to issue certificates for ASA VPN users.
EAP_Authentication_Certificate_Template—For EAP authentication.
pxGrid_Certificate_Template—For pxGrid controller while generating the certificate from the Certificate Provisioning Portal.

Note

Certificate templates that use the ECC key type can be used only with the internal Cisco ISE CA.

Before you begin

Ensure that you have configured the CA settings.

Procedure

Step 1

Choose Administration > System > CA Service > Internal CA Certificate Template.

Step 2

Enter a name for the internal CA template. For example, Internal_CA_Template.

Step 3

(Optional) Enter values for the Organizational Unit, Organization, City, State, and Country fields.

We do not support UTF-8 characters in the certificate template fields (Organizational Unit, Organization, City, State, and Country). Certificate provisioning fails if UTF-8 characters are used in the certificate template.

The username of the internal user generating the certificate is used as the Common Name of the certificate. Cisco ISE Internal CA does not support "+" or "*" characters in the Common Name field. Ensure that your username does not include "+" or "*" special characters.

Step 4

Specify the Subject Alternative Name (SAN) and the validity period of the certificate.

Step 5

Specify a Key Type. Choose RSA or ECC.

The following table lists the operating systems and versions that support ECC along with the curve types that are supported. If your devices are not running a supported operating system or on a supported version, you can use RSA-based certificates instead.

Operating System

Supported Versions

Supported Curve Types

Windows

8 and later

P-256, P-384, and P-521

Android

4.4 and later

Note

Android 6.0 requires May 2016 patch to support ECC certificates.

All curve types (except Android 6.0, which does not support the P-192 curve type).

Windows 7 and Apple iOS do not natively support ECC for EAP-TLS authentication. This release of Cisco ISE does not support the use of ECC certificates on MAC OS X devices.

If the devices in your network run an operating system that is not supported (Windows 7, MAC OS X, or Apple iOS, we recommend that you choose RSA as the Key Type.

Step 6

(Applicable if you choose the RSA Key Type) Specify a key size. You must choose 1024 or a higher key size.

Step 7

(Applicable only if you choose the ECC Key Type) Specify the Curve Type. The default is P-384.

Step 8

Choose ISE Internal CA as the SCEP RA Profile.

Step 9

Enter the validity period in days. The default is 730 days. Valid range is between 1 and 730.

Step 10

Specify the Extended Key Usage. Check the Client Authentication check box if you want the certificate to be used for client authentication. Check the Server Authentication check box if you want the certificate to be used for server authentication.

Step 11

Click Submit.

The internal CA certificate template is created and will be used by the client provisioning policy.

What to do next

Create a Native Supplicant Profile to be Used in Client-Provisioning Policy

You can create native supplicant profiles to enable users to bring personal devices to your Corporate network. Cisco ISE uses different policy rules for different operating systems. Each client provisioning policy rule contains a native supplicant profile, which specifies which provisioning wizard is to be used for which operating system.

Before you begin

Configure the CA certificate template in Cisco ISE.
Open up TCP port 8905 and UDP port 8905 to enable client agents and supplicant provisioning wizard installation. For more information about port usage, see the "Cisco ISE Appliance Ports Reference" appendix in the Cisco Identity Services Engine Hardware Installation Guide.

Procedure

Step 1

Choose Policy > Policy Elements > Results > Client Provisioning > Resources.

Step 2

Choose Add > Native Supplicant Profile.

Step 3

Enter a name for the native supplicant profile. For example, EAP_TLS_INTERNAL.

Step 4

Choose ALL from the Operating System drop-down list.

Note

The MAC OS version 10.10 user should manually connect to the provisioned SSID for dual-SSID PEAP flow.

Step 5

Check the Wired or Wireless check box.

Step 6

Choose TLS from the Allowed Protocol drop-down list.

Step 7

Choose the CA certificate template that you created earlier.

Step 8

Click Submit.

What to do next

Download Agent Resources from Cisco for Windows and MAC OS X Operating Systems

For Windows and MAC OS X operating systems, you must download the remote resources from the Cisco site.

Before you begin

Ensure that you are able to access the appropriate remote location to download client provisioning resources to Cisco ISE, by verifying that the proxy settings for your network are correctly configured.

Procedure

Step 1	Choose Policy > Policy Elements > Resources > Client Provisioning > Resources.
Step 2	Choose Add > Agent resources from Cisco site.
Step 3	Check the check boxes next to the Windows and MAC OS X packages. Be sure to include the latest versions.
Step 4	Click Save.

What to do next

Create Client-Provisioning Policy Rules for Apple iOS, Android, and MAC OS X Devices

Client provisioning resource policies determine which users receive which version (or versions) of resources (agents, agent compliance modules, and agent customization packages/profiles) from Cisco ISE upon login and user session initiation.

When you download the agent compliance module, it always overwrites the existing one, if any, available in the system.

To enable employees to bring iOS, Android, MAC OS X devices, you must create policy rules for each of these devices on the Client Provisioning Policy page.

Before you begin

You must have configured the required native supplicant profiles and downloaded the required agents from the Client Provisioning Policy pages.

Procedure

Step 1	Choose Policy > Client Provisioning.
Step 2	Create client provisioning policy rules for Apple iOS, Android, and MAC OS X devices.
Step 3	Click Save.

What to do next

Configure the Dot1X Authentication Policy Rule for TLS-Based Authentication

This task shows how to update the Dot1X authentication policy rule for TLS-based authentications.

Before you begin

Ensure that you have the certificate authentication profile created for TLS-based authentication.

Procedure

Step 1	Choose Policy > Policy Sets.
Step 2	Click the arrow icon from the View column to open the Set view screen and view, manage, and update the authentication policy. The default rule-based authentication policy includes a rule for Dot1X authentication.
Step 3	To edit the conditions for the Dot1X authentication policy rule, hover over the cell in the Conditions column and click . The Conditions Studio opens.
Step 4	From the Actions column in the Dot1X policy rule, click the cog icon and then from the drop-down menu, insert a new policy set by selecting any of the insert or duplicate options, as necessary. A new row appears in the Policy Sets table.
Step 5	Enter a name for the rule. For example, eap-tls.
Step 6	From the Conditions column, click the (+) symbol.
Step 7	Create the required conditions in the Conditions Studio Page. In the Editor section, click the Click To Add an Attribute text box, and select the required Dictionary and Attribute (for example, Network Access:UserName Equals User1). You can drag and drop a Library condition to the Click To Add An Attribute text box.
Step 8	Click Use.
Step 9	Leave the default rule as is.
Step 10	Click Save.

What to do next

Create Authorization Profiles for Central Web Authentication and Supplicant-Provisioning Flows

You must define authorization profiles to determine the access that must be granted to the user after the certificate-based authentication is successful.

Before you begin

Ensure that you have configured the required access control lists (ACLs) on the wireless LAN controller (WLC). Refer to the TrustSec How-To Guide: Using Certificates for Differentiated Access for information on how to create the ACLs on the WLC.

This example assumes that you have created the following ACLs on the WLC.

NSP-ACL - For native supplicant provisioning
BLACKHOLE - For restricting access to block listed devices
NSP-ACL-Google - For provisioning Android devices

Procedure

Step 1	Choose Policy > Policy Elements > Results > Authorization > Authorization Profiles.
Step 2	Click Add to create a new authorization profile.
Step 3	Enter a name for the authorization profile.
Step 4	From the Access Type drop-down list, choose ACCESS_ACCEPT.
Step 5	Click Add to add the authorization profiles for central web authentication, central web authentication for Google Play, native supplicant provisioning, and native supplicant provisioning for Google.
Step 6	Click Save.

What to do next

Create Authorization Policy Rules

Cisco ISE evaluates the authorization policy rules and grants the user access to the network resources based on the authorization profile specified in the policy rule.

Before you begin

Ensure that you have created the required authorization profiles.

Procedure

Step 1	Choose Policy > Policy Sets, and expand the policy set to view the authorization policy rules.
Step 2	Insert additional policy rules above the default rule.
Step 3	Click Save.

CA Service Policy Reference

This section provides reference information for the authorization and client provisioning policy rules that you must create before you can enable the Cisco ISE CA service.

Client-Provisioning Policy Rules for Certificate Services

This section lists the client provisioning policy rules that you must create while using the Cisco ISE certificate services. The following table provides the details.


Rule Name	Identity Groups	Operating Systems	Other Conditions	Results
iOS	Any	Apple iOS All	Condition(s)	EAP_TLS_INTERNAL (the native supplicant profile that you created earlier). If you are using an external CA, select the native supplicant profile that you have created for the external CA.
Android	Any	Android	Condition(s)	EAP_TLS_INTERNAL (the native supplicant profile that you created earlier). If you are using an external CA, select the native supplicant profile that you have created for the external CA.
MAC OS X	Any	MACOSX	Condition(s)	Under the Native Supplicant Configuration, specify the following: Config Wizard: Select the MAC OS X supplicant wizard that you downloaded from the Cisco site. Wizard Profile: Choose the EAP_TLS_INTERNAL native supplicant profile that you created earlier. If you are using an external CA, select the native supplicant profile that you have created for the external CA.

Authorization Profiles for Certificate Services

This section lists the authorization profiles that you must create for enabling certificate-based authentication in Cisco ISE. You must have already created the ACLs (NSP-ACL and NSP-ACL-Google) on the wireless LAN controller (WLC).

CWA - This profile is for devices that go through the central web authentication flow. Check the Web Authentication check box, choose Centralized from the drop-down list, and enter NSP-ACL in the ACL text box.
CWA_GooglePlay - This profile is for Android devices that go through the central web authentication flow. This profile enables Android devices to access Google Play Store and download the Cisco Network Setup Assistant. Check the Web Authentication check box, choose Centralized from the drop-down list, and enter NSP-ACL-Google in the ACL text box.
NSP - This profile is for non-Android devices that go through the supplicant provisioning flow. Check the Web Authentication check box, choose Supplicant Provisioning from the drop-down list, and enter NSP-ACL in the ACL text box.
NSP-Google - This profile is for Android devices that go through the supplicant provisioning flow. Check the Web Authentication check box, choose Supplicant Provisioning from the drop-down list, and enter NSP-ACL-Google in the ACL text box.

Review the default Blackhole_Wireless_Access authorization profile. The Advanced Attributes Settings should be:

Cisco:cisco-av-pair = url-redirect=https://ip:port/blacklistportal/gateway?portal=PortalID
Cisco:cisco-av-pair = url-redirect-acl=BLACKHOLE

Authorization Policy Rules for Certificate Services

This section lists the authorization policy rules that you must create while enabling the Cisco ISE CA service.

Corporate Assets-This rule is for corporate devices that connect to the corporate wireless SSID using 802.1X and MSCHAPV2 protocol.
Android_SingleSSID-This rule is for Android devices that access the Google Play Store to download the Cisco Network Setup Assistant for provisioning. This rule is specific to single SSID setup.
Android_DualSSID-This rule is for Android devices that access the Google Play Store to download the Cisco Network Setup Assistant for provisioning. This rule is specific to dual SSID setup.
CWA-This rule is for devices that go through the central web authentication flow.
NSP-This rule is for devices that go through the native supplicant provisioning flow using a certificate for EAP-TLS authentication.
EAP-TLS-This rule is for devices that have completed the supplicant provisioning flow and are provisioned with a certificate. They will be given access to the network.

The following table lists the attributes and values that you must choose while configuring authorization policy rules for the Cisco ISE CA service. This example assumes that you have the corresponding authorization profiles configured in Cisco ISE as well.


Rule Name	Conditions	Permissions (Authorization Profiles to be Applied)
Corporate Assets	Corp_Assets AND (Wireless 802.1X AND Network Access:AuthenticationMethod EQUALS MSCHAPV2)	PermitAccess
Android_SingleSSID	(Wireless 802.1X AND Network Access:AuthenticationMethod EQUALS MSCHAPV2 AND Session:Device-OS EQUALS Android)	NSP_Google
Android_DualSSID	(Wireless_MAB AND Session:Device-OS EQUALS Android)	CWA_GooglePlay
CWA	Wireless_MAB	CWA
NSP	(Wireless 802.1X AND Network Access:AuthenticationMethod EQUALS MSCHAPV2)	NSP
EAP-TLS	(Wireless 802.1X AND Network Access:AuthenticationMethod EQUALS x509_PKI	PermitAccess

Cisco ISE CA Issues Certificates to ASA VPN Users

ISE CA issues certificates to client machines connecting over ASA VPN. Using this feature, you can automatically provision certificates to end devices that connect over ASA VPN.

Cisco ISE uses the Simple Certificate Enrollment Protocol (SCEP) for enrollment and to provision certificates to the client machines. The AnyConnect client sends the SCEP request to the ASA over an HTTPS connection. The ASA evaluates the request and enforces policies before it relays the request to Cisco ISE over an HTTP connection established between Cisco ISE and ASA. The response from the Cisco ISE CA is relayed back to the client. The ASA cannot read the contents of the SCEP message and functions as a proxy for the Cisco ISE CA. The Cisco ISE CA decrypts the SCEP message from the client and sends the response in an encrypted form.

The ISE CA SCEP URL is http://<IP Address or FQDN of ISE CA server>:9090/auth/caservice/pkiclient.exe. If you are using FQDN of the ISE node, the DNS server connected to ASA must be able to resolve the FQDN.

You can configure certificate renewal before expiration in the AnyConnect Client profile. If the certificate has already expired, the renewal flow is similar to a new enrollment.

Supported versions include:

Cisco ASA 5500 Series Adaptive Security Appliances that run software version 8.x
Cisco AnyConnect VPN version 2.4 or later

VPN Connection Certificate-Provisioning Flow

Figure 4. Certificate Provisioning for ASA VPN Users

The user initiates a VPN connection.
The AnyConnect client scans the client machine and sends the attributes such as the unique device identifier (for example, IMEI) to the ASA.
The ASA requests certificate-based authentication from the client. The authentication fails because there is no certificate.
The ASA proceeds to primary user authentication (AAA) using the username/password and passes the information to the authentication server (ISE).
1. If authentication fails, the connection is terminated immediately.
2. If authentication passes, limited access is granted. You can configure dynamic access policies (DAP) for client machines that request a certificate using the aaa.cisco.sceprequired attribute. You can set the value for this attribute to “true” and apply ACLs and web ACLs.
The VPN connection is established after the relevant policies and ACLs are applied. The client starts key generation for SCEP only after AAA authentication succeeds and the VPN connection is established.
The client starts the SCEP enrollment and sends SCEP requests to ASA over HTTP.
ASA looks up the session information of the request and relays the request to ISE CA, if the session is allowed for enrollment.
ASA relays the response from ISE CA back to the client.
If enrollment succeeds, the client presents a configurable message to the user and disconnects the VPN session.
The user can again authenticate using the certificate and a normal VPN connection is established.

Configure Cisco ISE CA to Issue Certificates to ASA VPN Users

You must perform the following configurations on Cisco ISE and ASA to provision certificates to ASA VPN users.

Before you begin

Ensure that the VPN user account is present in Cisco ISE internal or external identity source.
Ensure that the ASA and the Cisco ISE Policy Service Nodes are synchronized using the same NTP server.

Procedure

Step 1	Define the ASA as a network access device in Cisco ISE. See Add a Network Device in Cisco ISE for information on how to add ASA as a network device.
Step 2	Configure Group Policy in ASA.
Step 3	Configure AnyConnect Connection Profile for SCEP Enrollment.
Step 4	Configure a VPN Client Profile in ASDM.
Step 5	Import ISE Server Certificates in to ASA.

Add a Network Device in Cisco ISE

You can add a network device in Cisco ISE or use the default network device.

You can also add a network device in the Network Devices (Work Centers > Device Administration > Network Resources > Network Devices) window.

Before you begin

The AAA function must be enabled on the network device to be added. See Command to Enable AAA Functions.

Procedure

Step 1	Choose Administration > Network Resources > Network Devices.
Step 2	Click Add.
Step 3	Enter the corresponding values in the Name, Description, and IP Address fields.
Step 4	Choose the required values from the Device Profile, Model Name, Software Version, and Network Device Group drop-down lists.
Step 5	(Optional) Check the RADIUS Authentication Settings check box to configure the RADIUS protocol for authentication.
Step 6	(Optional) Check the TACACS Authentication Settings check box to configure the TACACS protocol for authentication.
Step 7	(Optional) Check the SNMP Settings check box to configure SNMP for the Cisco ISE profiling service to collect information from the network device.
Step 8	(Optional) Check the Advanced Trustsec Settings check box to configure a Cisco TrustSec-enabled device.
Step 9	Click Submit.

Configure Group Policy in ASA

Configure a group policy in ASA to define the ISE CA URL for AnyConnect to forward the SCEP enrollment request.

Procedure

Step 1	Log in to Cisco ASA ASDM.
Step 2	From the Remote Access VPN navigation pane on the left, click Group Policies.
Step 3	Click Add to create a group policy.
Step 4	Enter a name for the group policy. For example, ISE_CA_SCEP.
Step 5	In the SCEP forwarding URL field, uncheck the Inherit check box and enter the ISE SCEP URL with port number. If you are using the FQDN of the ISE node, the DNS server connected to ASA must be able to resolve the FQDN of the ISE node. Example: http://ise01.cisco.com:9090/auth/caservice/pkiclient.exe.
Step 6	Click OK to save the group policy.

Configure AnyConnect Connection Profile for SCEP Enrollment

Configure an AnyConnect connection profile in ASA to specify the ISE CA server, authentication method, and ISE CA SCEP URL.

Procedure

Step 1	Log in to Cisco ASA ASDM.
Step 2	From the Remote Access VPN navigation pane on the left, click AnyConnect Connection Profiles.
Step 3	Click Add to create a connection profile.
Step 4	Enter a name for the connection profile. For example, Cert-Group.
Step 5	(Optional) Enter a description for the connection profile in the Aliases field. For example, SCEP-Call-ASA.
Step 6	In the Authentication area, specify the following: Method—Click the Both radio button AAA Server Group—Click Manage and choose your ISE server
Step 7	In the Client Address Assignment area, select the DHCP server and client address pools to use.
Step 8	In the Default Group Policy area, click Manage and select the Group Policy that you have created with the ISE SCEP URL and port number. Example: For example, ISE_CA_SCEP.
Step 9	Choose Advanced > General and check the Enable Simple Certificate Enrollment Protocol check box for this connection profile.
Step 10	Click OK. Your AnyConnect connection profile is created.

What to do next

Configure a VPN Client Profile in ASDM

Configure a VPN client profile in AnyConnect for SCEP enrollment.

Procedure

Step 1	Log in to Cisco ASA ASDM.
Step 2	From the Remote Access VPN navigation pane on the left, click AnyConnect Client Profile.
Step 3	Select the client profile that you want to use and click Edit.
Step 4	Click Certificate Enrollment from the Profile navigation pane on the left.
Step 5	Check the Certificate Enrollment check box.
Step 6	Enter the values in the following fields: Certificate Expiration Threshold—The number of days before the certificate expiration date that AnyConnect warns users their certificate is going to expire (not supported when SCEP is enabled). The default is zero (no warning displayed). The range of values is zero to 180 days. Automatic SCEP Host—Enter the host name and connection profile (tunnel group) of the ASA that has SCEP certificate retrieval configured. Enter a Fully Qualified Domain Name (FQDN) or a connection profile name of the ASA. For example, the hostname asa.cisco.com and the connection profile name Cert_Group. CA URL—Identifies the SCEP CA server. Enter the FQDN or IP Address of the ISE server. For example, http://ise01.cisco.com:9090/auth/caservice/pkiclient.exe.
Step 7	Enter values for the Certificate Contents that define how the client requests the contents of the certificate.
Step 8	Click OK. The AnyConnect client profile is created. Refer to the Cisco AnyConnect Secure Mobility Client for your version of AnyConnect for additional information.

Import Cisco ISE CA Certificates into ASA

Import the Cisco ISE internal CA certificates into the ASA.

Before you begin

Export the Cisco ISE internal CA certificates. Go to Administration > System > Certificates > Certificate Authority > Certificate Authority Certificates. Check the check boxes next to Certificate Services Node CA and Certificate Services Root CA certificates and export them, one certificate at a time.

Procedure

Step 1	Log in to Cisco ASA ASDM.
Step 2	From the Remote Access VPN navigation pane on the left, choose Certificate Management > CA Certificates.
Step 3	Click Add and select the Cisco ISE internal CA certificates to import them in to ASA.

Revoke an Endpoint Certificate

If you need to revoke a certificate issued to an employee's personal device, you can revoke it from the Endpoint Certificates page. For example, if an employee's device has been stolen or lost, you can log in to the Cisco ISE Admin portal and revoke the certificate issued to that device from the Endpoint Certificates page. You can filter the data on this page based on the Friendly Name, Device Unique Id, or Serial Number.

If a PSN (sub CA) is compromised, you can revoke all certificates issued by that PSN by filtering on the Issued By field from the Endpoint Certificates page.

When you revoke a certificate issued to an employee, if there is an active session (authenticated using that certificate), the session is terminated immediately. Revoking a certificate ensures that unauthorized users do not have any access to resources as soon as the certificate is revoked.

Procedure

Step 1	Choose Administration > System > Certificates > Certificate Authority > Issued Certificates.
Step 2	Check the check box next to the endpoint certificate that you want to revoke and click Revoke. You can search for the certificate based on the Friendly Name and Device Type.
Step 3	Enter the reason for revoking the certificate.
Step 4	Click Yes.

OCSP Services

The Online Certificate Status Protocol (OCSP) is a protocol that is used for checking the status of x.509 digital certificates. This protocol is an alternative to the Certificate Revocation List (CRL) and addresses issues that result in handling CRLs.

Cisco ISE has the capability to communicate with OCSP servers over HTTP to validate the status of certificates in authentications. The OCSP configuration is configured in a reusable configuration object that can be referenced from any certificate authority (CA) certificate that is configured in Cisco ISE.

You can configure CRL and/or OCSP verification per CA. If both are selected, then Cisco ISE first performs verification over OCSP. If a communication problem is detected with both the primary and secondary OCSP servers, or if an unknown status is returned for a given certificate, Cisco ISE switches to checking the CRL.

Cisco ISE CA Service Online Certificate Status Protocol Responder

The Cisco ISE CA OCSP responder is a server that communicates with OCSP clients. The OCSP clients for the Cisco ISE CA include the internal Cisco ISE OCSP client and OCSP clients on the Adaptive Security Appliance (ASA). The OCSP clients should communicate with the OCSP responder using the OCSP request/response structure defined in RFC 2560, 5019.

The Cisco ISE CA issues a certificate to the OCSP responder. The OCSP responder listens on port 2560 for any incoming requests. This port is configured to allow only OCSP traffic.

The OCSP responder accepts a request that follows the structure defined in RFC 2560, 5019. Nonce extension is supported in the OCSP request. The OCSP responder obtains the status of the certificate and creates an OCSP response and signs it. The OCSP response is not cached on the OCSP responder, although you can cache the OCSP response on the client for a maximum period of 24 hours. The OCSP client should validate the signature in the OCSP response.

The self-signed CA certificate (or the intermediate CA certificate if ISE acts as an intermediate CA of an external CA) on the PAN issues the OCSP responder certificate. This CA certificate on the PAN issues the OCSP certificates on the PAN and PSNs. This self-signed CA certificate is also the root certificate for the entire deployment. All the OCSP certificates across the deployment are placed in the Trusted Certificates Store for ISE to validate any response signed using these certificates.

Note

Cisco ISE receives from OCSP responder servers a thisUpdate value, which indicates the time since the last certificate revocation. If the thisUpdate value is greater than 7 days, the OCSP certificate verification fails in Cisco ISE.

OCSP Certificate Status Values

OCSP services return the following values for a given certificate request:

Good—Indicates a positive response to the status inquiry. It means that the certificate is not revoked, and the state is good only until the next time interval (time to live) value.
Revoked—The certificate was revoked.
Unknown—The certificate status is unknown. OCSP service returns this value if the certificate was not issued by the CA of this OCSP responder.
Error—No response was received for the OCSP request.

OCSP High Availability

Cisco ISE has the capability to configure up to two OCSP servers per CA, and they are called primary and secondary OCSP servers. Each OCSP server configuration contains the following parameters:

URL—The OCSP server URL.
Nonce—A random number that is sent in the request. This option ensures that old communications cannot be reused in replay attacks.
Validate response—Cisco ISE validates the response signature that is received from the OCSP server.

In case of timeout (which is 5 seconds), when Cisco ISE communicates with the primary OCSP server, it switches to the secondary OCSP server.

Cisco ISE uses the secondary OCSP server for a configurable amount of time before attempting to use the primary server again.

OCSP Failures

The three general OCSP failure scenarios are as follows:

Failed OCSP cache or OCSP client side (Cisco ISE) failures.
Failed OCSP responder scenarios, for example:

The first primary OCSP responder not responding, and the secondary OCSP responder responding to the Cisco ISE OCSP request.

Errors or responses not received from Cisco ISE OCSP requests.

An OCSP responder may not provide a response to the Cisco ISE OCSP request or it may return an OCSP Response Status as not successful. OCSP Response Status values can be as follows:
- tryLater
- signRequired
- unauthorized
- internalError
- malformedRequest
  
  There are many date-time checks, signature validity checks and so on, in the OCSP request. For more details, refer to RFC 2560 X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSP which describes all the possible states, including the error states.
Failed OCSP reports

Add OCSP Client Profiles

You can use the OCSP Client Profile page to add new OCSP client profiles to Cisco ISE.

Before you begin

If the Certificate Authority (CA) is running the OCSP service on a nonstandard port (other than 80 or 443), you must configure ACLs on the switch to allow for communication between Cisco ISE and the CA on that port. For example:

permit tcp <source ip> <destination ip> eq <OCSP port number>

Procedure

Step 1	Choose Administration > System > Certificates > Certificate Management > OCSP Client Profile.
Step 2	Enter the values to add an OCSP Client Profile.
Step 3	Click Submit.

OCSP Statistics Counters

Cisco ISE uses OCSP counters to log and monitor the data and health of the OCSP servers. Logging occurs every five minutes. Cisco ISE sends a syslog message to the Monitoring node and it is preserved in the local store. The local store contains data from the previous five minutes. After Cisco ISE sends the syslog message, the counters are recalculated for the next interval. This means, after five minutes, a new five-minute window interval starts again.

The following table lists the OCSP syslog messages and their descriptions.

Table 3. OCSP Syslog Messages
Message	Description
OCSPPrimaryNotResponsiveCount	The number of nonresponsive primary requests
OCSPSecondaryNotResponsiveCount	The number of nonresponsive secondary requests
OCSPPrimaryCertsGoodCount	The number of ‘good’ certificates that are returned for a given CA using the primary OCSP server
OCSPSecondaryCertsGoodCount	The number of ‘good’ statuses that are returned for a given CA using the primary OCSP server
OCSPPrimaryCertsRevokedCount	The number of ‘revoked’ statuses that are returned for a given CA using the primary OCSP server
OCSPSecondaryCertsRevokedCount	The number of ‘revoked’ statuses that are returned for a given CA using the secondary OCSP server
OCSPPrimaryCertsUnknownCount	The number of ‘Unknown’ statuses that are returned for a given CA using the primary OCSP server
OCSPSecondaryCertsUnknownCount	The number of ‘Unknown’ statuses that are returned for a given CA using the secondary OCSP server
OCSPPrimaryCertsFoundCount	The number of certificates that were found in cache from a primary origin
OCSPSecondaryCertsFoundCount	The number of certificates that were found in cache from a secondary origin
ClearCacheInvokedCount	How many times clear cache was triggered since the interval
OCSPCertsCleanedUpCount	How many cached entries were cleaned since the t interval
NumOfCertsFoundInCache	Number of the fulfilled requests from the cache
OCSPCacheCertsCount	Number of certificates that were found in the OCSP cache

Requirements for CA to Interoperate with Cisco ISE

Client Certificate Requirements for Certificate-Based Authentication

While using a CA server with Cisco ISE, make sure that the following requirements are met:

Key size should be 1024, 2048, or higher. In CA server, the key size is defined using certificate template. You can define the key size on Cisco ISE using the supplicant profile.
Key usage should allow signing and encryption in extension.
While using GetCACapabilities through the SCEP protocol, cryptography algorithm and request hash should be supported. It is recommended to use RSA and SHA1.

Online Certificate Status Protocol (OCSP) is supported. This is not directly used in BYOD, but a CA which can act as an OCSP server can be used for certificate revocation.

Note

Enterprise Java Beans Certificate Authority (EJBCA) is not supported by Cisco ISE for proxy SCEP. EJBCA is supported by Cisco ISE for standard EAP authentication like PEAP, EAP-TLS, and so on.

If you use an enterprise PKI to issue certificates for Apple iOS devices, ensure that you configure key usage in the SCEP template and enable the Key Encipherment option.

If you use Microsoft CA, edit the Key Usage Extension in the certificate template. In the Encryption area, click the Allow Key Exchange only with Key Encryption (Key encipherment) radio button and check the Allow Encryption of User Data check box.
Cisco ISE supports the use of RSASSA-PSS algorithm for trusted certificates and endpoint certificates for EAP-TLS authentication. When you view the certificate, the signature algorithm is listed as 1.2.840.113549.1.1.10 instead of the algorithm name.

Note

If you use the Cisco ISE internal CA for the BYOD flow, the Admin certificate should not be signed using the RSASSA-PSS algorithm (by an external CA). The Cisco ISE internal CA cannot verify an Admin certificate that is signed using this algorithm and the request would fail.

For certificate-based authentication with Cisco ISE, the client certificate should meet the following requirements:

Table 4. Client-Certificate Requirements for RSA and ECC

RSA

Supported Key Sizes

1024, 2048, and 4096 bits

Supported Secure Hash Algorithms (SHA)

SHA-1 and SHA-2 (includes SHA-256)

ECC ¹ ²

Supported Curve Types

P-192, P-256, P-384, and P-521

Supported Secure Hash Algorithm (SHA)

SHA-256

Client Machine Operating Systems and Supported Curve Types

Windows

8 and later

P-256, P-384, and P-521

Android

4.4 and later

Note

Android 6.0 requires May 2016 patch to support ECC certificates.

All curve types (except Androidv6.0, which does not support the P-192 curve type).

¹ Windows 7 and Apple iOS do not natively support ECC for EAP-TLS authentication.

² This release of Cisco ISE does not support the use of ECC certificates on MAC OS X devices.

Cisco Identity Services Engine Administrator Guide, Release 2.3

Bias-Free Language

Results

Chapter: Manage Certificates

Manage Certificates

Certificate Management in Cisco ISE

Configure Certificates in Cisco ISE to Enable Secure Access

Certificate Usage

Certificate Matching in Cisco ISE

Validity of X.509 Certificates

Enable Public Key Infrastructure in Cisco ISE

Procedure

Wildcard Certificates

Wildcard Certificate Support in Cisco ISE

Wildcard Certificates for HTTPS and Extensible Authentication Protocol Communication

Fully Qualified Domain Name in URL Redirection

Advantages of Using Wildcard Certificates

Disadvantages of Using Wildcard Certificates

Wildcard Certificate Compatibility

Certificate Hierarchy

System Certificates

View System Certificates

Before you begin

Procedure

Import a System Certificate

Before you begin

Procedure

Generate a Self-Signed Certificate

Before you begin

Edit a System Certificate

Before you begin

Procedure

Delete a System Certificate

Procedure

Export a System Certificate

Before you begin

Procedure

Trusted Certificates Store

Certificates in Trusted Certificates Store

Trusted Certificate Naming Constraints

View Trusted Certificates

Before you begin

Procedure

Change the Status of a Certificate in Trusted Certificates Store

Add a Certificate to Trusted Certificates Store

Before you begin

Edit a Trusted Certificate

Before you begin

Procedure

Delete a Trusted Certificate

Procedure

Export a Certificate from Trusted Certificates Store

Before you begin

Procedure

Import a Root Certificate to Trusted Certificate Store

Before you begin

Procedure

What to do next

Trusted Certificate Import Settings

Certificate Chain Import

Certificate-Signing Requests

Create a Certificate-Signing Request and Submit it to a Certificate Authority

Procedure

Bind a CA-Signed Certificate to a Certificate Signing Request

Before you begin

Procedure

What to do next

Export a Certificate-Signing Request

Before you begin

Procedure

Set Up Certificates for Portal Use

Procedure

Reassign Default Portal Certificate Group Tag to CA-Signed Certificate

Procedure

Associate Portal Certificate Tag Before You Register a Node

Procedure

User and Endpoint Certificate Renewal

Dictionary Attributes Used in Policy Conditions for Certificate Renewal

Authorization Policy Condition for Certificate Renewal

CWA Redirect to a Renew Certificate