Principal
A principal is a security identity representing an entity, such as a person, application, service, machine, or process, in an authentication or authorization system.
Authorization in Action
A principal is an entity, such as a person, machine, or process, that can initiate an action in an authorization system.
- How it is used
- Frames the requesting actor in authorization decisions and policy evaluation.
- How deep it goes
- Defines the term, distinguishes related identity terms, and follows it through PARC, ACL, Cedar, OPA, and request mapping.
- Examples
- Uses a parent acting for a child, folder ACL entries, Alice’s report request, and Cedar document-sharing payloads.
- What you can do after
- Apply it via Cedar or policy enforcement components by mapping requests to principal, action, resource, and context.
Azure Security
A security principal is an identity or identity-bearing entity, such as a user, group, service principal, or managed identity, that can receive permissions in an authorization system.
- How it is used
- Identifies the user, group, application, or managed identity that receives Azure RBAC permissions.
- How deep it goes
- Defines principals in authentication and Azure RBAC, then relates them to credentials, tokens, roles, scopes, and assignments.
- Examples
- Uses a user, administrator group, storage-account application, managed identity, and Virtual Machine Contributor assignment.
- What you can do after
- Operate/configure it by assigning or removing Azure RBAC roles for a selected principal and scope.
Microsoft Azure in Action
A security principal is an identity-bearing object, such as a user, group, or application, that can request access to an Azure resource.
- How it is used
- Identifies the identity receiving Azure access through role-based access control.
- How deep it goes
- Defines identity types and connects them to role assignments, but does not descend into authentication or permission-evaluation internals.
- Examples
- Uses Joe, the sysadmin group, and the Alpaca-Ma-Bags application as concrete principal examples.
- What you can do after
- Apply it via Azure RBAC by selecting an identity, role, and scope for a role assignment.
Apache Kafka in Action
A principal is the authenticated security identity representing a user or system when accessing protected resources.
- How it is used
- Represents authenticated Kafka clients during authorization and access-control decisions.
- How deep it goes
- Defines identity naming, TLS/SASL authentication context, principal mapping, and ACL evaluation, but does not enumerate all SASL options.
- Examples
- Uses certificate Distinguished Names, CN mapping rules, named service principals, and online-shop topic permissions.
- What you can do after
- Operate/configure Kafka client identities, map certificate names, and assign least-privilege ACLs to services.
Kafka for Architects
A principal is an identity representing a client, broker, user, or service in a security system.
- How it is used
- Identifies authenticated Kafka participants for authorization rules and quota assignment.
- How deep it goes
- Connects identity derivation, SASL authentication, ACL structure, and quota targeting, with configuration examples but no implementation internals.
- Examples
- Uses TLS certificate identities, SASL clients, quota assignments, and a card-service producer ACL as concrete examples.
- What you can do after
- Configure authentication identities, assign quotas, and write ACLs that govern Kafka resource operations.
Related concepts
- role assignmentpart of · A role assignment is an access-control configuration that grants a principal an authorization role or specified permissions for a defined scope.
- PARC modelpart of · The PARC model is an authorization framework that describes an access decision using a principal, action, resource, and conditions or context.
- ClaimsPrincipalimplemented by · ClaimsPrincipal is a .NET security class representing a principal through one or more identities and their associated claims.
- policy templateused by · A policy template is a reusable authorization policy structure containing placeholders that are filled with specific principals, resources, or other values later.
- subjectcontrasts with · A subject is an entity designated as the focus of representation, data modeling, or an authorization policy.
- role-based access controluses · Role-based access control is an authorization model that assigns permissions to roles and grants users or other principals access through their assigned roles.
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