Add role control

API/ROLAC.API/Authorization/HasPermissionAttribute.cs

@@ -0,0 +1,32 @@
+using Microsoft.AspNetCore.Authorization;
+
+namespace ROLAC.API.Authorization;
+
+/// <summary>
+/// Gates an action/controller on a configurable permission. Usage:
+/// <c>[HasPermission(Modules.Members, PermissionActions.Write)]</c>.
+/// Encodes the policy name <c>PERM:&lt;module&gt;:&lt;action&gt;</c>, which
+/// <see cref="PermissionPolicyProvider"/> turns into a <see cref="PermissionRequirement"/>.
+/// </summary>
+[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true)]
+public class HasPermissionAttribute : AuthorizeAttribute
+{
+    public const string PolicyPrefix = "PERM:";
+
+    public HasPermissionAttribute(string module, string action)
+        => Policy = $"{PolicyPrefix}{module}:{action}";
+
+    /// <summary>Parses a policy name back into (module, action), or null if not a PERM policy.</summary>
+    public static (string Module, string Action)? Parse(string policyName)
+    {
+        if (!policyName.StartsWith(PolicyPrefix, StringComparison.Ordinal))
+            return null;
+
+        var body  = policyName[PolicyPrefix.Length..];
+        var split = body.IndexOf(':');
+        if (split <= 0 || split == body.Length - 1)
+            return null;
+
+        return (body[..split], body[(split + 1)..]);
+    }
+}