1.2. The Identity Management Domain
- IdM servers, which work as domain controllers
- IdM clients, which are enrolled with the servers
1.2.1. Identity Management Servers
188.8.131.52. Services Hosted by IdM Servers
- IdM uses the Kerberos protocol to support single sign-on. With Kerberos, users only need to present the correct username and password once and can access IdM services without the system prompting for credentials again.
- Kerberos is divided into two parts:
For details on how Kerberos works, see the System-Level Authentication Guide.
krb5kdcservice is the Kerberos Authentication service and Key Distribution Center (KDC) daemon.
kadminservice is the Kerberos database administration program.
- For information on how to authenticate using Kerberos in IdM, see Section 5.2, “Logging into IdM Using Kerberos”.
- For information on managing Kerberos in IdM, see Chapter 29, Managing the Kerberos Domain.
- LDAP directory server:
- The IdM internal LDAP directory server instance stores all IdM information, such as information related to Kerberos, user accounts, host entries, services, policies, DNS, and others.The LDAP directory server instance is based on the same technology as Red Hat Directory Server. However, it is tuned to IdM-specific tasks.
NoteThis guide refers to this component as Directory Server.
- Certificate Authority:
- The integrated Certificate Authority (CA) is based on the same technology as Red Hat Certificate System.
pkiis the Command-Line Interface for accessing Certificate System services.
- For more details on installing an IdM server with different CA configurations, see Section 2.3.2, “Determining What CA Configuration to Use”.
NoteThis guide refers to this component as Certificate System when addressing the implementation and as certificate authority when addressing the services provided by the implementation.For information relating to Red Hat Certificate System, a standalone Red Hat product, see Product Documentation for Red Hat Certificate System.
- Domain Name System (DNS):
- IdM uses DNS for dynamic service discovery. The IdM client installation utility can use information from DNS to automatically configure the client machine. After the client is enrolled in the IdM domain, it uses DNS to locate IdM servers and services within the domain.The
BIND (Berkeley Internet Name Domain)implementation of the DNS (Domain Name System) protocols in Red Hat Enterprise Linux includes the
named-pkcs11is a version of the
BINDDNS server built with native support for the PKCS#11 cryptographic standard.
- For more information about service discovery, see the System-Level Authentication Guide.
- For information on the
BINDDNS server, see the the Networking Guide.
- For information on using DNS with IdM and important prerequisites, see Section 2.1.5, “Host Name and DNS Configuration”.
- For details on installing an IdM server with or without integrated DNS, see Section 2.3.1, “Determining Whether to Use Integrated DNS”.
- Network Time Protocol:
- Many services require that servers and clients have the same system time, within a certain variance. For example, Kerberos tickets use time stamps to determine their validity and to prevent replay attacks. If the times between the server and client skew outside the allowed range, the Kerberos tickets are invalidated.By default, IdM uses the Network Time Protocol (NTP) to synchronize clocks over a network via the
ntpdservice. With NTP, a central server acts as an authoritative clock and the clients synchronize their times to match the server clock. The IdM server is configured as the NTP server for the IdM domain during the server installation process.
NoteRunning an NTP server on an IdM server installed on a virtual machine can lead to inaccurate time synchronization in some environments. To avoid potential problems, do not run NTP on IdM servers installed on virtual machines. For more information on the reliability of an NTP server on a virtual machine, see this Knowledgebase solution.
- Apache HTTP Server:
- The Apache HTTP web server provides the IdM Web UI, and also manages communication between the Certificate Authority and other IdM services.
- For more information about the Apache HTTP Server, see the System Administrator’s Guide.
- Samba / Winbind:
- Samba implements the Server Message Block (SMB) protocol, also known as the Common Internet File System (CIFS) protocol), in Red Hat Enterprise Linux. Via the
smbservice, the SMB protocol enables you to access resources on a server, such as file shares and shared printers. If you have configured a Trust with an Active Directory (AD) environment, the Winbind service manages communication between IdM servers and AD servers.
- One-time password (OTP) authentication:
- One-time passwords (OTP) are passwords that are generated by an authentication token for only one session, as part of two-factor authentication. OTP authentication is implemented in Red Hat Enterprise Linux via the
- For more information about OTP authentication, see Section 22.3, “One-Time Passwords”.
- Custodia is a Secrets Services provider, it stores and shares access to secret material such as passwords, keys, tokens, certificates.
- OpenDNSSEC is a DNS manager that automates the process of keeping track of DNS security extensions (DNSSEC) keys and the signing of zones. The
ipa-dnskeysyncdservuce manages synchronization between the IdM Directory Server and OpenDNSSEC.
Figure 1.1. The Identity Management Server: Unifying Services
1.2.2. Identity Management Clients
184.108.40.206. Services Hosted by IdM Clients
- System Security Services Daemon:
- The System Security Services Daemon (SSSD) is the client-side application that manages user authentication and caching credentials.Caching enables the local system to continue normal authentication operations if the IdM server becomes unavailable or if the client goes offline.
certmongerservice monitors and renews the certificates on the client. It can request new certificates for the services on the system.For more information about
certmonger, see the System-Level Authentication Guide.
Figure 1.2. Interactions Between IdM Services