ZyXEL Communications P-2802H-I Series, User Manual

Page: 228 / 418

Chapter 15 Certificates
P-2802H(W)(L)-I Series User’s Guide
228
15.12 Verifying a Trusted Remote Host’s Certificate
Certificates issued by certification authorities have the certification authority’s signature for
you to check. Self-signed certificates only have the signature of the host itself. This means that
you must be very careful when deciding to import (and thereby trust) a remote host’s self-
signed certificate.
15.12.1 Trusted Remote Host Certificate Fingerprints
A certificate’s fingerprints are message digests calculated using the MD5 or SHA1 algorithms.
The following procedure describes how to use a certificate’s fingerprint to verify that you have
the remote host’s actual certificate.
1 Browse to where you have the remote host’s certificate saved on your computer.
2 Make sure that the certificate has a “.cer” or “.crt” file name extension.
Figure 127 Remote Host Certificates
3
Double-click the certificate’s icon to open the Certificate window. Click the Details tab
and scroll down to the Thumbprint Algorithm and Thumbprint fields.
Figure 128 Certificate Details
Verify (over the phone for example) that the remote host has the same information in the
Thumbprint Algorithm and Thumbprint fields.