ZyXEL Communications P-660HN-F1, User Manual

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Chapter 15 Certificates
ADSL Series User’s Guide
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15.1.3 Verifying a Certificate
Before you import a trusted CA or trusted remote host certificate into the ZyXEL Device, you should
verify that you have the actual certificate. This is especially true of trusted CA certificates since the
ZyXEL Device also trusts any valid certificate signed by any of the imported trusted CA certificates.
You can use a certificate’s fingerprint to verify it. A certificate’s fingerprint is a message digest
calculated using the MD5 or SHA1 algorithms. The following procedure describes how to check a
certificate’s fingerprint to verify that you have the actual certificate.
1
Browse to where you have the certificate saved on your computer.
2
Make sure that the certificate has a “.cer” or “.crt” file name extension.
Figure 95
Certificates on Your Computer
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 96
Certificate Details
4
Use a secure method to verify that the certificate owner has the same information in the
Thumbprint Algorithm and Thumbprint fields. The secure method may very based on your
situation. Possible examples would be over the telephone or through an HTTPS connection.