SCEP

Simple Certificate Enrollment Protocol is an open-source certificate management protocol that enables IT administrators to issue certificates automatically. In addition, it provides some certificate use cases. One such is the integration with Mobile Device Management (MDM) systems. MDM uses the SCEP server to push a payload with the Simple Certificate Enrollment Protocol URL. The idea is for a PKI certificate enrollment of multiple devices used by the workforce of an organization. That way, the authentication connection between mobile devices, apps, and the organization's systems becomes seamless.

Simple Certificate Enrollment Protocol also uses its protocol to give a one-time password (OTP) via an out-of-bound (OOB) mechanism. The structure requires the submission of an OTP and certificate signing request for verification after creating a key pair. When the certificate is ready, a user places the request and performs the installation.

Simple Certificate Enrollment Protocol involves certain key elements for an enrollment process. First, it must standardize the exchange of information with a Certificate Authority (CA) before authenticating a request or issuing the certificate. The core components in the Simple Certificate Enrollment Protocol gateway include the following.

• SCEP URL: The Simple Certificate Enrollment Protocol URL instructs devices on communicating with the CA or PKI to obtain enrollment for the client certificate.
• SCEP Shared Secret: A shared secret refers to a case-sensitive and secure password between a Simple Certificate Enrollment Protocol server and the CA. It authenticates or verifies the domain and identities of the CA certificate vis-a-vis the appropriate server for signing certificates.
• SCEP Certificate Signing Request: Simple Certificate Enrollment Protocol certificate request precedes the first two processes. It involves creating and distributing a configuration profile that enables managed devices to auto-enroll for certificates via a request to the CA. After the authentication process, a signed certificate gets deployed to the device.
• SCEP Signing Certificate: MDM requires users to upload the Simple Certificate Enrollment Protocol signed certificate signed by the CA issuing certificates. It must include the entire certificate chain ( Intermediate CA, Root CA, End-entity Certificate, and signing certificate).

A SCEP client refers to implementing the Cisco system's Simple Certificate Enrollment Protocol with an automatic provision of client certificates via a Simple Certificate Enrollment Protocolserver and a CA. Part of its procedure entails an automatic renewal before the expiration.

In most organizations, some PCs or devices do not get joined to the domain for reasons best known to them. Nevertheless, these devices need clients for efficient operation and guidance against cyber threats. Therefore, a manual installation of a Simple Certificate Enrollment Protocol client becomes a necessity. In addition, it requires utilizing an account with limited administrative privileges.

The procedure entails logging into the server, navigating the software library to application management and packages, and following this to the configuration Manager Client Package and Properties window. Finally, the entire procedure leads to downloading the SCEP client.

One challenging aspect is the ability to locate the Simple Certificate Enrollment Protocol client installation media. Most times, the client-only copy gets bundled with the client installation package. However, copying the policy XML file and the SCEP install exe helps. The administrator has to manually run them on a target client to get a SCEP client with a similar configuration to a regularly deployed SCEP client.

SCEP client implements some features of SCEP, including:

• Automatic enrollment of client certificates via a pre-shared secret
• Manual enrollment of client certificate
• Acquisition of the CA certificates

Simple Certificate Enrollment Protocol is typically installed on servers or devices that require digital certificates. SCEP is used to automate the process of requesting and issuing digital certificates, making it a crucial component for many organizations that rely on certificate-based authentication and encryption.

Here are some common places where Simple Certificate Enrollment Protocol can be installed:

• Certificate Authorities (CAs): SCEP is often installed on the servers that operate as Certificate Authorities. These CAs are responsible for issuing digital certificates to devices or users. SCEP allows these CAs to automate the certificate issuance process.
• Network Devices: Some network devices, like routers, firewalls, and VPN gateways, can have SCEP clients or agents installed to request and renew certificates for secure communication and authentication. This is particularly common in enterprise environments.
• Mobile Device Management (MDM) Solutions: Many MDM solutions support SCEP to facilitate the distribution of digital certificates to mobile devices. SCEP can be integrated into MDM systems to manage certificates for smartphones and tablets.
• Web Servers: Web servers often use digital certificates for secure HTTPS connections. SCEP can be used to automate the renewal and provisioning of SSL/TLS certificates for web servers.
• Email Servers: Some email servers use digital certificates for secure email communication (e.g., S/MIME certificates). Simple Certificate Enrollment Protocol can be used to manage and issue these certificates.
• IoT Devices: In the context of the Internet of Things (IoT), SCEP can be installed on IoT devices to obtain and renew certificates, ensuring secure communication between devices and the IoT platform.
• Client Devices: SCEP clients can also be installed on individual devices, such as computers and mobile devices, to request and manage their own certificates, particularly in BYOD (Bring Your Own Device) scenarios.

The specific installation location of SCEP depends on the use case and the organization's certificate management strategy. In many cases, SCEP is integrated into existing systems or services that require certificates, enabling automation and simplifying certificate management.