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Cisco ASA 5500 Series Configuration Guide using ASDM
Chapter44 Configuring Digital Certificates
Authenticating Using the Local CA
Note Be sure to review all optional settings carefully before you enable the configured local CA. After
you enable it, the certificate issuer name and key size server values cannot be changed.
The self-signed certificate key usage extension enables key encryption, key signature, CRL signature,
and certificate signature.
Step3 When you enable the local CA for the first time, you must enter and confirm an alphanumeric Enable
passphrase, which must have a minimum of seven, alphanumeric characters. The passphrase protects the
local CA certificate and the local CA certificate key pair archived in storage, and secures the local CA
server from unauthorized or accidental shutdown. The passphrase is required to unlock the PKCS12
archive if the local CA certificate or key pair is lost and must be restored.
Note The Enable passphrase is required to enable the local CA server. Be sure to keep a record of the
Enable passphrase in a safe location.
Step4 Click Apply to save the local CA certificate and key pair, so the configuration is not lost if you reboot
the ASA.
Step5 To change or reconfigure the local CA after the local CA has been configured for the first time, you must
shut down the local CA server on the ASA by unchecking the Enable Certificate Authority Server
check box. In this state, the configuration and all associated files remain in storage and enrollment is
disabled.
After the configured local CA has been enabled, the following two settings are display-only:
•The Issuer Name field, which lists the issuer subject name and domain name, and is formed using
the username and the subject-name-default DN setting as cn=FQDN. The local CA server is the
entity that grants the certificate. The default certificate name is provided in the format,
cn=hostname.domainname.
•The CA Server Key Size setting, which is used for the server certificate generated for the local CA
server. Key sizes can be 512, 768, 1024, or 2048 bits per key. The default is 1024 bits per key.
Step6 From the drop-down list, choose the client key size of the key pair to be generated for each user
certificate issued by the local CA server. Key sizes can be 512, 768, 1024, or 2048 bits per key. The
default is 1024 bits per key.
Step7 Enter the CA certificate lifetime value, which specifies the number of days that the CA server certificate
is valid. The default is 3650 days (10 years). Make sure that you limit the validity period of the certificate
to less than the recommended end date of 03:14:08 UTC, January 19, 2038.
The local CA server automatically generates a replacement CA certificate 30 days before expiration,
which enables the replacement certificate to be exported and imported onto any other devices for local
CA certificate validation of user certificates that have been issued by the local CA after they have
expired.
To notify users of the upcoming expiration, the following syslog message appears in the Latest ASDM
Syslog Messages pane:
%ASA-1-717049: Local CA Server certificate is due to expire in days days and a replacement
certificate is available for export.
Note When notified of this automatic rollover, the administrator must take action to make sure that
the new local CA certificate is imported to all necessary devices before it expires.