Cisco Systems ASA5515K9, ASA 5500 Trust Relationships for Cisco UMA Deployments

50-5
Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter50 Configuring Cisco Mobility Advantage
Information about the Cisco Mobility Advantage Proxy Feature
In scenario 2 (Figure 50-3), PAT can be used to converge all client traffic into one source IP, so that the
firewall does not have to open up a wildcard pinhole for inbound traffic.
hostname(config)# access-list cumc extended permit tcp any host 172.16.27.41 eq 5443
versus
hostname(config)# access-list cumc extended permit tcp host 192.0.2.183 host 172.16.27.41
eq 5443
Trust Relationships for Cisco UMA Deployments
To establish a trust relationship between the Cisco UMC client and the ASA, the ASA uses the Cisco
UMA server certificate and keypair or the ASA obtains a certificate with the Cisco UMA server FQDN
(certificate impersonation). Between the ASA and the Cisco UMA server, the ASA and Cisco UMA
server use self-signed certificates or certificates issued by a local certificate authority.
Figure 50-4 shows how you can import the Cisco UMA server certificate onto the ASA. When the Cisco
UMA server has already enrolled with a third-party CA, you can import the certificate with the private
key onto the ASA. Then, the ASA has the full credentials of the Cisco UMA server. When a Cisco UMA
client connects to the Cisco UMA server, the ASA intercepts the handshake and uses the Cisco UMA
server certificate to perform the handshake with the client. The ASA also performs a handshake with the
server.
Figure50-4 How the Security Appliance Represents Cisco UMA – Private Key Sharing
Figure 50-5 shows another way to establish the trust relationship. Figure50-5 shows a green field
deployment, because each component of the deployment has been newly installed. The ASA enrolls with
the third-party CA by using the Cisco UMA server FQDN as if the ASA is the Cisco UMA server. When
the Cisco UMA client connects to the ASA, the ASA presents the certificate that has the Cisco UMA
server FQDN. The Cisco UMA client believes it is communicating to with the Cisco UMA server.
271643
Internet
Inspected and
Modified
(if needed)
Certificate
Authority
Certificate
Certificate with
Private Key
ASA
Enroll with FQDN
of Cisco UMA
Key 1 Key 2
TLS (Self-signed,
or from local CA)
TLS (Cisco UMA Certificate)
3rd Party CA
Cisco UMA
Cisco UMC Client