Generating A Mini Certificate - Linksys RTP300 - Broadband Router With 2 Phone Ports Administration Manual

The CA public key is used to verify the MC received from the other end. If the MC is invalid, the
call will not switch to secure mode. The MC and the 1024-bit CA public key are concatenated
and base64 encoded into the single parameter Mini Certificate. The 512-bit private key is base64
encoded into the SRTP Private Key parameter, which should be kept secret, like a password.
(Mini Certificate and SRTP Private Key are configured in the Line tabs.)
Because the secure call establishment relies on exchange of information embedded in message
bodies of SIP INFO requests/responses, the service provider must ensure that the network
infrastructure allows the SIP INFO messages to pass through with the message body
unmodified.

Generating a Mini Certificate

Linksys provides a Mini Certificate Generator for the generation of mini certificates and private
keys.
• Partners in North America can find the Mini Certificate Generator on the SPA Utilities
page at the Linksys Partner Connection (LPC) at Linksys.com.
• Partners in Europe, the Middle East, and Africa can find the Mini Certificate Generator on
the Firmware and Tools page at linksys-itsp.com.
NOTE: The partner sites require a logon.
The Mini Certificate Generator uses the following syntax:
gen_mc ca-key user-name user-id expire-date
Where:
• is a text file with the base64 encoded 1024-bit CA private/public key pairs for
ca-key
signing/verifying the MC, such as the following:
9CC9aYU1X5lJuU+EBZmi3AmcqE9U1LxEOGwopaGyGOh3VyhKgi6JaVtQZt87PiJINKW8XQj3B9Qqe3VgYx
WCQNa335YCnDsenASeBxuMIEaBCYd1l1fVEodJZOGwXwfAde0MhcbD0kj7LVlzcsTyk2TZYTccnZ75TuTj
j13qvYs=
5nEtOrkCa84/mEwl3D9tSvVLyliwQ+u/Hd+C8u5SNk7hsAUZaA9TqH8Iw0J/
IqSrsf6scsmundY5j7Z5mK5J9uBxSB8t8vamFGD0pF4zhNtbrVvIXKI9kmp4vph1C5jzO9gDfs3MF+zjyY
rVUFdM+pXtDBxmM+fGUfrpAuXb7/k=
• is the name of the subscriber, such as "Joe Smith". Maximum length is 32
user-name
characters
• is the User ID of the subscriber, which must match exactly the user-id used in the
user-id
INVITE when making the call, such as "14083331234". The maximum length is 16
characters.
• is the expiration date of the MC, such as "00:00:00 1/1/34" (34=2034).
expire-date
Internally the date is encoded as a fixed 12B string: 000000010134
Linksys ATA Administration Guide
Secure Call Implementation
59