Xtreme Power Conversion Corporation
Web/SNMP Cards
Page 38
UPS Management
It can be seen that the key fingerprint is exactly the same.
SSL Certificates
HTTPS is not a protocol itself, but it actually refers to HTTP communication over SSL (Secure Sockets Layer) con-
nection. HTTPS uses public-key cryptography to protect the communication. With HTTPS, the server sends back
its identification in the form of a digital certificate. The certificate usually contains the server name, the trusted
certificate authority (CA), and the server’s public encryption key.
The server certificate includes a digital signature from a certification authority. Each browser is normally equipped
with a set of CA root certificates of commercial authorities. The web browsers perform a set of verifications over
the digital certificate in order to validate the certificate and start the HTTPS communication. The main checks are
substantially the following:
• The client verifies that the issuing Certificate Authority (CA) is on its list of trusted CAs.
• The client checks the server’s certificate validity period
Further to this, the client may compare the actual DNS name of the server to the DNS name on the certificate
(though this last point may be browser dependent).
Below is a sample of the results of these checks, when browser attempts to establish an HTTP connection to the
web server embedded in the SNMP/Web adapter (the sample is take from Internet Explorer, but similar indications
can be obtained with the most common browsers):