Introduction to certificates

Hypertext Transfer Protocol Secure (HTTPS) is an extension of the Hypertext Transfer Protocol (HTTP) for secure communication over a computer network. In HTTPS, the communication protocol is encrypted using Transport Layer Security (TLS), or its predecessor, Secure Sockets Layer (SSL).

In XProtect VMS, secure communication is obtained by using TLS/SSL with asymmetric encryption (RSA).

TLS/SSL uses a pair of keys—one private, one public—to authenticate, secure, and manage secure connections.

A certificate authority (CA) is anyone who can issue root certificates. This can be an internet service that issues root certificates, or anyone who manually generates and distributes a certificate. A CA can issue certificates to web services, that is to any software using https communication. This certificate contains two keys, a private key and a public key. The public key is installed on the clients of a web service (service clients) by installing a public certificate. The private key is used for signing server certificates that must be installed on the server. Whenever a service client calls the web service, the web service sends the server certificate, including the public key, to the client. The service client can validate the server certificate using the already installed public CA certificate. The client and the server can now use the public and private server certificates to exchange a secret key and thereby establish a secure TLS/SSL connection.

For manually distributed certificates, certificates must be installed before the client can make such a verification.

See Transport Layer Security for more information about TLS.

In XProtect VMS, the following locations are where you can enable TLS/SSL encryption:

  • In the communication between the management server and the recording servers, event servers, and mobile servers
  • On the recording server in the communication with clients, servers, and integrations that retrieve data streams from the recording server
  • In the communication between clients and the mobile server

In this guide, the following are referred to as clients:

  • XProtect Smart Client
  • Management Client
  • Management Server (for System Monitor and for images and AVI video clips in email notifications)
  • XProtect Mobile Server
  • XProtect Event Server
  • XProtect LPR
  • Milestone Open Network Bridge
  • XProtect DLNA Server
  • Sites that retrieve data streams from the recording server through Milestone Interconnect
  • Third-party MIP SDK integrations that support HTTPS
  • For solutions built with MIP SDK 2018 R3 or earlier that access recording servers:
    • If the integrations are made using MIP SDK libraries, they need to be rebuilt with MIP SDK 2019 R1
    • If the integrations communicate directly with the Recording Server APIs without using MIP SDK libraries, the integrators must add HTTPS support themselves
    • If in doubt, ask your vendor who supplied the integration

    • Certificate distribution

    The graphic illustrates the basic concept of how certificates are signed, trusted, and distributed in XProtect VMS.

    A certificate authority (CA) is anyone who can issue root certificates. A CA certificate acts as a trusted third-party, trusted by both the subject/owner (server) and by the party that verifies the certificate (clients) (see Create CA certificate).

    The public certificate must be trusted on all client computers. In this way the clients can verify the validity of the certificates issued by the CA (see Install certificates on the clients).

    The CA certificate is used to issue private server authentication certificates to the servers (see Create SSL certificate).

    The created private SSL certificates must be imported to the Windows Certificate Store on all servers (see Import SSL certificate).

    Requirements for the private SSL certificate:

    • Issued to the server so that the server's host name is included in the certificate, either as subject (owner) or in the list of DNS names that the certificate is issued to
    • Trusted on all computers running services or applications that communicate with the service on the servers, by trusting the CA certificate that was used to issue the SSL certificate
    • The service account that runs the server must have access to the private key of the certificate on the server.

    Certificates have an expiry date. You will not receive a warning when a certificate is about to expire. If a certificate expires, the clients will no longer trust the server with the expired certificate and thus cannot communicate with it.
    To renew the certificates, follow the steps in this guide as you did when you created certificates.