Let’s begin.<\/p>\n
<\/a>What Is Authorization?<\/h2>\nBefore we dive deeper into the implementation of view-based authorization, let’s take a step back and review the concept of authorization.<\/p>\n
Authorization refers to the process of determining what actions or resources a user is permitted to access.<\/strong> It is based on their identity and associated permissions. In other words, it ensures that the users only interact with the parts of an application that they are authorized to use.<\/strong><\/p>\nOften it’s the process that comes after authentication<\/a>. While authentication verifies who a user claims to be, authorization determines the level of access granted to authenticated users.<\/strong><\/p>\n<\/a>View-Based Authorization<\/h2>\nIn view-based authorization, we conditionally display or enable different view parts, such as buttons, links, and form fields, based on the user’s authorization status.<\/strong><\/p>\nUnlike other forms of authorization such as route-based or resource-based authorization<\/a>, which focus on controlling access to entire routes or data resources, view-based authorization targets individual components within the user interface.<\/p>\nHere, we often leverage user roles or policies to determine access to UI elements. We can check whether the current user belongs to a specific role and accordingly render UI elements for them. View-based authorization also allows us to move the authorization logic from the backend to the presentation layer. We can apply authorization rules directly on the razor views without cluttering the controller or backend APIs with authorization-related code.<\/p>\n
<\/a>Role-Based Access Control (RBAC)<\/h2>\nBuilding upon the concept of view-based authorization, Role-Based Access Control (RBAC)<\/a> can help us refine the access within ASP.NET Core Razor views.<\/p>\nRBAC is an authorization technique where access decisions are determined by a user’s role within the system.<\/strong> It allows us to restrict access to specific UI elements based on the roles associated with the current user:<\/p>\n@if (User.IsInRole(\"Admin\"))\r\n{\r\n <a class=\"btn btn-danger\" href=\"\/Delete?id=@document.Id\">Delete<\/a>\r\n}<\/pre>\nHere, we only display the Delete<\/em> link to users who belong to the Admin<\/em> role. Thus, users who do not have administrator access are unable to delete resources.<\/p>\n<\/a>Policy-Based Access Control (PBAC)<\/h2>\nExpanding on the concept of view-based authorization and Role-Based Access Control, let’s explore Policy-Based Access Control (PBAC)<\/a>.<\/p>\nPBAC is an authorization model where we decide user access based on policies. A policy<\/em> refers to a set of rules that define whether a user is authorized to access a particular resource or perform a specific action.<\/strong> Policies are dependent on claims, <\/em>which are individual pieces of information about an authenticated user. When a user requests access to a resource, we evaluate these policy requirements against the role or claims associated with the user.<\/strong><\/p>\nThese policies allow for fine-grained control over access to UI components within ASP.NET Core Razor views:<\/p>\n
@if ((await AuthorizationService.AuthorizeAsync(User, \"EditDocument\")).Succeeded)\r\n{\r\n <a class=\"btn btn-primary\" href=\"\/Edit?id=@document.Id\">Edit<\/a>\r\n}<\/pre>\nHere, we use the AuthorizeAsync()<\/code> method to check whether the current user is authorized according to the EditDocument<\/em> policy defined in the application’s policy configuration. If the user is authorized, we display the Edit<\/em> link.<\/p>\n<\/a>Implement View-Based Authorization in ASP.NET Core<\/h2>\nLet’s create an application in which, based on a user’s roles and policies, we’ll conditionally display UI elements in the view.<\/p>\n
Firstly, we use the dotnet new webapp<\/code> command to create a new ASP.NET Core Razor Pages project in which to implement view-based authorization. We’ll be using the SQLite Entity Framework package to manage database persistence.<\/p>\nNow let’s create a Document<\/code> class:<\/p>\npublic class Document\r\n{\r\n public int Id { get; set; }\r\n public required string Title { get; set; }\r\n public string Content { get; set; } = string.Empty;\r\n}<\/pre>\nThis class will act as the base model for our application.<\/p>\n
Next, let’s create a context class<\/a> named DocumentContext<\/code> that inherits from IdentityDbContext<IdentityUser><\/code>. This will allow us to extend the capabilities of IdentityDbContext<\/code> to include default user and role management features provided by ASP.NET Core Identity.<\/p>\n<\/a>Identity Configuration<\/h3>\nNow let’s set up the default user and role management using DocumentContext<\/code> as the database:<\/p>\nbuilder.Services.AddDefaultIdentity<IdentityUser>(options =>\r\n{\r\n options.SignIn.RequireConfirmedAccount = true;\r\n})\r\n.AddRoles<IdentityRole>()\r\n.AddEntityFrameworkStores<DocumentContext>();<\/pre>\nHere, we configure the default Identity system with IdentityUser<\/code> as the user type. IdentityUser<\/code> is the built-in user model provided by ASP.NET Core Identity, which includes properties like Id<\/code>, UserName<\/code>, and Email<\/code>.<\/p>\nWe also extend the Identity system to support role-based authorization. It registers IdentityRole<\/code> as the role type associated with users.<\/p>\n<\/a>Policy Configuration<\/h3>\nNext, let’s set up some policies in the application to restrict access to the resources:<\/p>\n
builder.Services.AddAuthorizationBuilder()\r\n .AddPolicy(\"EditDocument\", policy => policy.RequireClaim(\"Permission\", \"CanEdit\"))\r\n .AddPolicy(\"DeleteDocument\", policy => policy.RequireRole(\"Admin\"));<\/pre>\nThe EditDocument\u00a0<\/em>policy requires the users to have a Permission<\/em> claim with the value CanEdit, <\/em>while\u00a0<\/em>the DeleteDocument<\/em> policy requires the user to be an admin.<\/p>\nAt this point, we can create and apply initial migrations to generate our Documents<\/em> table and default ASP.NET Identity tables such as AspNetUsers<\/em>\u00a0and AspNetRoles<\/em>.<\/p>\n<\/a>User Creation for View-Based Authorization<\/h3>\nTo demonstrate how view-based authorization works for different users, let’s seed our application with different user roles:<\/p>\n
private static void SeedUser(UserManager<IdentityUser> userManager, string email, string password,\r\n string roleName, params Claim[] claims)\r\n{\r\n var user = userManager.FindByEmailAsync(email).Result;\r\n\r\n if (user is null)\r\n {\r\n user = new IdentityUser { UserName = email, Email = email, EmailConfirmed = true };\r\n userManager.CreateAsync(user, password);\r\n }\r\n\r\n if (!userManager.IsInRoleAsync(user, roleName).Result)\r\n {\r\n userManager.AddToRoleAsync(user, roleName);\r\n }\r\n\r\n foreach (var claim in claims)\r\n {\r\n if (!userManager.GetClaimsAsync(user)\r\n .Result\r\n .Any(c => c.Type == claim.Type && c.Value == claim.Value))\r\n {\r\n userManager.AddClaimAsync(user, claim);\r\n }\r\n }\r\n}<\/pre>\nUsing the SeedUser()<\/code> method, we can create users in the AspNetUsers <\/em>table and assign them specific roles or claims. Let’s create three different types of users – admin<\/em>, editor<\/em>, and user<\/em>:<\/p>\nSeedUser(userManager,\r\n \"admin@docmanager.com\",\r\n \"Admin123!\",\r\n \"Admin\",\r\n new Claim(\"Permission\", \"CanEdit\"));\r\n\r\nSeedUser(userManager,\r\n \"editor@docmanager.com\",\r\n \"Editor123!\",\r\n \"Editor\",\r\n new Claim(\"Permission\", \"CanEdit\"));\r\n\r\nSeedUser(userManager, \"user@docmanager.com\", \"User123!\", \"User\");<\/pre>\nThe roles “Admin”, “Editor”, and “User” represent different levels of access or privileges within the application. In addition, we give a claim to the “Editor” and “Admin” users, which asserts that those users can edit documents within the application.<\/p>\n
<\/a>View-Based Authorization in Action<\/h2>\nNow that we have our tables, users, and their respective roles set up, let’s see our Document Management application in action.<\/p>\n
Let’s create an Index page that a logged-in user lands on:<\/p>\n
<table class=\"table table-striped\">\r\n <thead>\r\n <tr>\r\n <th>Title<\/th>\r\n <th>Actions<\/th>\r\n <\/tr>\r\n <\/thead>\r\n <tbody>\r\n @foreach (var document in Model.Documents)\r\n {\r\n <tr>\r\n <td>@document.Title<\/td>\r\n <td>\r\n @if ((await AuthorizationService.AuthorizeAsync(User, \"EditDocument\")).Succeeded)\r\n {\r\n <a class=\"btn btn-primary\" href=\"\/Edit?id=@document.Id\">Edit<\/a>\r\n }\r\n @if (User.IsInRole(\"Admin\"))\r\n {\r\n <a class=\"btn btn-danger\" href=\"\/Delete?id=@document.Id\">Delete<\/a>\r\n }\r\n <\/td>\r\n <\/tr>\r\n }\r\n <\/tbody>\r\n<\/table>\r\n<hr\/>\r\n<p><a class=\"btn btn-success\" href=\"\/Add\">Add New Document<\/a><\/p><\/pre>\nWe inject the AuthorizationService<\/code> into the view. Using this, we can dynamically perform authorization checks directly within the Razor Page. Finally, authorization policies (\"EditDocument\"<\/code>) and role-based checks (User.IsInRole(\"Admin\")<\/code>) dictate which actions are available to the user.<\/p>\n<\/a>User Interface Differences<\/h3>\nLet’s see how the application user interface varies for different types of users.<\/p>\n
A “User” doesn’t have the permission to edit or delete documents. Thus, all they see is an option to add new documents:<\/p>\n
![\"UI](\"https:\/\/code-maze.com\/wp-content\/uploads\/2024\/05\/msedge_BPIhYjB9Ud.png\")
<\/a><\/p>\nAn “Editor” has permission to edit the existing documents. Thus, in addition to the ability to add new documents, they can also perform “Edit” actions:<\/p>\n
![\"UI](\"https:\/\/code-maze.com\/wp-content\/uploads\/2024\/05\/msedge_QicJrrJjgr.png\")
<\/a><\/p>\nFinally, an “Admin” has all the permissions, so they can add, edit, and delete a document:<\/p>\n
![\"UI](\"https:\/\/code-maze.com\/wp-content\/uploads\/2024\/05\/msedge_dS9kJaGb5V.png\")
<\/a><\/p>\nHere, we render different action buttons conditionally based on the user’s permissions, thus ensuring a controlled user experience where each user only sees what’s relevant to them.<\/p>\n
<\/a>Benefits of View-Based Authorization<\/h2>\nView-based authorization offers several advantages that enhance the flexibility and user experience of web applications.<\/p>\n
It allows us to dynamically control the visibility of UI elements based on a user’s permissions and roles. In other words, users only see the content they are authorized to access, leading to a more intuitive user interface.<\/p>\n
Because we embed the authorization logic directly into the client-side code, our application becomes more responsive, and the backend services are less complex. As the views become more self-contained with the authorization logic, it becomes easier to update authorization rules without impacting the overall application architecture.<\/p>\n
<\/a>Drawbacks of View-Based Authorization<\/h2>\nIf our application depends solely on conditionally rendered view controls, a malicious user can easily bypass the authorization.\u00a0<\/p>\n
Often it’s the process that comes after authentication<\/a>. While authentication verifies who a user claims to be, authorization determines the level of access granted to authenticated users.<\/strong><\/p>\n In view-based authorization, we conditionally display or enable different view parts, such as buttons, links, and form fields, based on the user’s authorization status.<\/strong><\/p>\n Unlike other forms of authorization such as route-based or resource-based authorization<\/a>, which focus on controlling access to entire routes or data resources, view-based authorization targets individual components within the user interface.<\/p>\n Here, we often leverage user roles or policies to determine access to UI elements. We can check whether the current user belongs to a specific role and accordingly render UI elements for them. View-based authorization also allows us to move the authorization logic from the backend to the presentation layer. We can apply authorization rules directly on the razor views without cluttering the controller or backend APIs with authorization-related code.<\/p>\n Building upon the concept of view-based authorization, Role-Based Access Control (RBAC)<\/a> can help us refine the access within ASP.NET Core Razor views.<\/p>\n RBAC is an authorization technique where access decisions are determined by a user’s role within the system.<\/strong> It allows us to restrict access to specific UI elements based on the roles associated with the current user:<\/p>\n Here, we only display the Delete<\/em> link to users who belong to the Admin<\/em> role. Thus, users who do not have administrator access are unable to delete resources.<\/p>\n Expanding on the concept of view-based authorization and Role-Based Access Control, let’s explore Policy-Based Access Control (PBAC)<\/a>.<\/p>\n PBAC is an authorization model where we decide user access based on policies. A policy<\/em> refers to a set of rules that define whether a user is authorized to access a particular resource or perform a specific action.<\/strong> Policies are dependent on claims, <\/em>which are individual pieces of information about an authenticated user. When a user requests access to a resource, we evaluate these policy requirements against the role or claims associated with the user.<\/strong><\/p>\n These policies allow for fine-grained control over access to UI components within ASP.NET Core Razor views:<\/p>\n Here, we use the Let’s create an application in which, based on a user’s roles and policies, we’ll conditionally display UI elements in the view.<\/p>\n Firstly, we use the Now let’s create a This class will act as the base model for our application.<\/p>\n Next, let’s create a context class<\/a> named Now let’s set up the default user and role management using Here, we configure the default Identity system with We also extend the Identity system to support role-based authorization. It registers Next, let’s set up some policies in the application to restrict access to the resources:<\/p>\n The EditDocument\u00a0<\/em>policy requires the users to have a Permission<\/em> claim with the value CanEdit, <\/em>while\u00a0<\/em>the DeleteDocument<\/em> policy requires the user to be an admin.<\/p>\n At this point, we can create and apply initial migrations to generate our Documents<\/em> table and default ASP.NET Identity tables such as AspNetUsers<\/em>\u00a0and AspNetRoles<\/em>.<\/p>\n To demonstrate how view-based authorization works for different users, let’s seed our application with different user roles:<\/p>\n Using the The roles “Admin”, “Editor”, and “User” represent different levels of access or privileges within the application. In addition, we give a claim to the “Editor” and “Admin” users, which asserts that those users can edit documents within the application.<\/p>\n Now that we have our tables, users, and their respective roles set up, let’s see our Document Management application in action.<\/p>\n Let’s create an Index page that a logged-in user lands on:<\/p>\n We inject the Let’s see how the application user interface varies for different types of users.<\/p>\n A “User” doesn’t have the permission to edit or delete documents. Thus, all they see is an option to add new documents:<\/p>\n An “Editor” has permission to edit the existing documents. Thus, in addition to the ability to add new documents, they can also perform “Edit” actions:<\/p>\n Finally, an “Admin” has all the permissions, so they can add, edit, and delete a document:<\/p>\n Here, we render different action buttons conditionally based on the user’s permissions, thus ensuring a controlled user experience where each user only sees what’s relevant to them.<\/p>\n View-based authorization offers several advantages that enhance the flexibility and user experience of web applications.<\/p>\n It allows us to dynamically control the visibility of UI elements based on a user’s permissions and roles. In other words, users only see the content they are authorized to access, leading to a more intuitive user interface.<\/p>\n Because we embed the authorization logic directly into the client-side code, our application becomes more responsive, and the backend services are less complex. As the views become more self-contained with the authorization logic, it becomes easier to update authorization rules without impacting the overall application architecture.<\/p>\n If our application depends solely on conditionally rendered view controls, a malicious user can easily bypass the authorization.\u00a0<\/p>\n<\/a>View-Based Authorization<\/h2>\n
<\/a>Role-Based Access Control (RBAC)<\/h2>\n
@if (User.IsInRole(\"Admin\"))\r\n{\r\n <a class=\"btn btn-danger\" href=\"\/Delete?id=@document.Id\">Delete<\/a>\r\n}<\/pre>\n<\/a>Policy-Based Access Control (PBAC)<\/h2>\n
@if ((await AuthorizationService.AuthorizeAsync(User, \"EditDocument\")).Succeeded)\r\n{\r\n <a class=\"btn btn-primary\" href=\"\/Edit?id=@document.Id\">Edit<\/a>\r\n}<\/pre>\nAuthorizeAsync()<\/code> method to check whether the current user is authorized according to the EditDocument<\/em> policy defined in the application’s policy configuration. If the user is authorized, we display the Edit<\/em> link.<\/p>\n<\/a>Implement View-Based Authorization in ASP.NET Core<\/h2>\n
dotnet new webapp<\/code> command to create a new ASP.NET Core Razor Pages project in which to implement view-based authorization. We’ll be using the SQLite Entity Framework package to manage database persistence.<\/p>\nDocument<\/code> class:<\/p>\npublic class Document\r\n{\r\n public int Id { get; set; }\r\n public required string Title { get; set; }\r\n public string Content { get; set; } = string.Empty;\r\n}<\/pre>\nDocumentContext<\/code> that inherits from IdentityDbContext<IdentityUser><\/code>. This will allow us to extend the capabilities of IdentityDbContext<\/code> to include default user and role management features provided by ASP.NET Core Identity.<\/p>\n<\/a>Identity Configuration<\/h3>\n
DocumentContext<\/code> as the database:<\/p>\nbuilder.Services.AddDefaultIdentity<IdentityUser>(options =>\r\n{\r\n options.SignIn.RequireConfirmedAccount = true;\r\n})\r\n.AddRoles<IdentityRole>()\r\n.AddEntityFrameworkStores<DocumentContext>();<\/pre>\nIdentityUser<\/code> as the user type. IdentityUser<\/code> is the built-in user model provided by ASP.NET Core Identity, which includes properties like Id<\/code>, UserName<\/code>, and Email<\/code>.<\/p>\nIdentityRole<\/code> as the role type associated with users.<\/p>\n<\/a>Policy Configuration<\/h3>\n
builder.Services.AddAuthorizationBuilder()\r\n .AddPolicy(\"EditDocument\", policy => policy.RequireClaim(\"Permission\", \"CanEdit\"))\r\n .AddPolicy(\"DeleteDocument\", policy => policy.RequireRole(\"Admin\"));<\/pre>\n
<\/a>User Creation for View-Based Authorization<\/h3>\n
private static void SeedUser(UserManager<IdentityUser> userManager, string email, string password,\r\n string roleName, params Claim[] claims)\r\n{\r\n var user = userManager.FindByEmailAsync(email).Result;\r\n\r\n if (user is null)\r\n {\r\n user = new IdentityUser { UserName = email, Email = email, EmailConfirmed = true };\r\n userManager.CreateAsync(user, password);\r\n }\r\n\r\n if (!userManager.IsInRoleAsync(user, roleName).Result)\r\n {\r\n userManager.AddToRoleAsync(user, roleName);\r\n }\r\n\r\n foreach (var claim in claims)\r\n {\r\n if (!userManager.GetClaimsAsync(user)\r\n .Result\r\n .Any(c => c.Type == claim.Type && c.Value == claim.Value))\r\n {\r\n userManager.AddClaimAsync(user, claim);\r\n }\r\n }\r\n}<\/pre>\nSeedUser()<\/code> method, we can create users in the AspNetUsers <\/em>table and assign them specific roles or claims. Let’s create three different types of users – admin<\/em>, editor<\/em>, and user<\/em>:<\/p>\nSeedUser(userManager,\r\n \"admin@docmanager.com\",\r\n \"Admin123!\",\r\n \"Admin\",\r\n new Claim(\"Permission\", \"CanEdit\"));\r\n\r\nSeedUser(userManager,\r\n \"editor@docmanager.com\",\r\n \"Editor123!\",\r\n \"Editor\",\r\n new Claim(\"Permission\", \"CanEdit\"));\r\n\r\nSeedUser(userManager, \"user@docmanager.com\", \"User123!\", \"User\");<\/pre>\n
<\/a>View-Based Authorization in Action<\/h2>\n
<table class=\"table table-striped\">\r\n <thead>\r\n <tr>\r\n <th>Title<\/th>\r\n <th>Actions<\/th>\r\n <\/tr>\r\n <\/thead>\r\n <tbody>\r\n @foreach (var document in Model.Documents)\r\n {\r\n <tr>\r\n <td>@document.Title<\/td>\r\n <td>\r\n @if ((await AuthorizationService.AuthorizeAsync(User, \"EditDocument\")).Succeeded)\r\n {\r\n <a class=\"btn btn-primary\" href=\"\/Edit?id=@document.Id\">Edit<\/a>\r\n }\r\n @if (User.IsInRole(\"Admin\"))\r\n {\r\n <a class=\"btn btn-danger\" href=\"\/Delete?id=@document.Id\">Delete<\/a>\r\n }\r\n <\/td>\r\n <\/tr>\r\n }\r\n <\/tbody>\r\n<\/table>\r\n<hr\/>\r\n<p><a class=\"btn btn-success\" href=\"\/Add\">Add New Document<\/a><\/p><\/pre>\nAuthorizationService<\/code> into the view. Using this, we can dynamically perform authorization checks directly within the Razor Page. Finally, authorization policies (\"EditDocument\"<\/code>) and role-based checks (User.IsInRole(\"Admin\")<\/code>) dictate which actions are available to the user.<\/p>\n<\/a>User Interface Differences<\/h3>\n
<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a>Benefits of View-Based Authorization<\/h2>\n
<\/a>Drawbacks of View-Based Authorization<\/h2>\n