SharpGrip AuthorizationChecker

Builds

Introduction

SharpGrip AuthorizationChecker is a security system that provides an easy and effective way to check access on objects.

Installation

Reference NuGet package SharpGrip.AuthorizationChecker (https://www.nuget.org/packages/SharpGrip.AuthorizationChecker).

Add the AuthorizationChecker security system to your service collection via the extension method.

public void ConfigureServices(IServiceCollection services)
{
    services.AddAuthorizationChecker();
}

Configuration

Properties

Property	Default value	Description
AccessDecisionStrategy	AccessDecisionStrategy.Affirmative	The access decision strategy used to determine if a given mode is allowed on a given subject.
UnanimousVoteAllowIfAllAbstain	false	Configures the access result outcome on AccessDecisionStrategy.Unanimous access decision strategies if all the subject's voters abstain from voting.

Access decision strategies

Strategy	Description
AccessDecisionStrategy.Affirmative	Grants access as soon as there is one IVoter instance granting access.
AccessDecisionStrategy.Majority	Grants access if there are more IVoter instances granting access than denying it.
AccessDecisionStrategy.Unanimous	Grants access if there are no IVoter instances denying access.

Via the services.AddAuthorizationChecker() extension method

using SharpGrip.AuthorizationChecker.Extensions;
using SharpGrip.AuthorizationChecker.Options;

public void ConfigureServices(IServiceCollection services)
{
    services.AddAuthorizationChecker(options =>
    {
        options.AccessDecisionStrategy = AccessDecisionStrategy.Majority;
        options.UnanimousVoteAllowIfAllAbstain = true;
    });
}

Via the services.Configure() method

using SharpGrip.AuthorizationChecker.Extensions;
using SharpGrip.AuthorizationChecker.Options;

public void ConfigureServices(IServiceCollection services)
{
    services.AddAuthorizationChecker();

    services.Configure<AuthorizationCheckerOptions>(options =>
    {
        options.AccessDecisionStrategy = AccessDecisionStrategy.Majority;
        options.UnanimousVoteAllowIfAllAbstain = true;
    });
}

Usage

Adding voters

Create a new class and implement either the IVoter<TSubject> or the IVoter<TSubject, TUser> interface.

IVoter<TSubject>

public class CarVoter : IVoter<Car>
{
    /// <summary>
    /// Determines if this <see cref="IVoter{TSubject}"/> instance will vote on the mode and subject.
    /// </summary>
    /// <param name="mode">The mode.</param>
    /// <param name="subject">The subject.</param>
    /// <returns>True if this <see cref="IVoter{TSubject}"/> instance will vote, False otherwise.</returns>
    public bool WillVote(string mode, Car subject)
    {
        return true;
    }

    /// <summary>
    /// Votes on the mode and subject.
    /// </summary>
    /// <param name="mode">The mode.</param>
    /// <param name="subject">The subject.</param>
    /// <returns>True if this <see cref="IVoter{TSubject}"/> instance allows access, False otherwise.</returns>
    public bool Vote(string mode, Car subject)
    {
        return mode switch
        {
            "create" => false,
            "read" => true,
            "update" => false,
            "delete" => true,
            _ => false
        };
    }
}

IVoter<TSubject, TUser>

public class CarVoter : IVoter<Car, User>
{
    /// <summary>
    /// Determines if this <see cref="IVoter{TSubject, TUser}"/> instance will vote on the mode and subject.
    /// </summary>
    /// <param name="mode">The mode.</param>
    /// <param name="subject">The subject.</param>
    /// <param name="user">The user.</param>
    /// <returns>True if this <see cref="IVoter{TSubject, TUser}"/> instance will vote, False otherwise.</returns>
    public bool WillVote(string mode, Car subject, User user)
    {
        return true;
    }

    /// <summary>
    /// Votes on the mode and subject.
    /// </summary>
    /// <param name="mode">The mode.</param>
    /// <param name="subject">The subject.</param>
    /// <param name="user">The user.</param>
    /// <returns>True if this <see cref="IVoter{TSubject, TUser}"/> instance allows access, False otherwise.</returns>
    public bool Vote(string mode, Car subject, User user)
    {
        return mode switch
        {
            "create" => true,
            "read" => false,
            "update" => true,
            "delete" => false,
            _ => true
        };
    }
}

Checking access

Inject the IAuthorizationChecker service and call one of the methods below:

Checking access directly

Car car = new Car();
User user = new User();

// Resolves to `IVoter<TSubject>` voter instances using the configured (or default) access decision strategy.
bool result = authorizationChecker.IsAllowed("edit", car);

// Resolves to `IVoter<TSubject, TUser>` voter instances using the configured (or default) access decision strategy.
bool result = authorizationChecker.IsAllowed("edit", car, user);

// Resolves to `IVoter<TSubject>` voter instances using the provided (`AccessDecisionStrategy.Unanimous`) access decision strategy.
bool result = authorizationChecker.IsAllowed("edit", car, AccessDecisionStrategy.Unanimous);

// Resolves to `IVoter<TSubject, TUser>` voter instances using the provided (`AccessDecisionStrategy.Unanimous`) access decision strategy.
bool result = authorizationChecker.IsAllowed("edit", car, user, AccessDecisionStrategy.Unanimous);

Retrieving the authorization result and checking access

Car car = new Car();
User user = new User();

// Resolves to `IVoter<TSubject>` voter instances using the configured (or default) access decision strategy.
IAuthorizationResult<Car> authorizationResult = authorizationChecker.GetAuthorizationResult("edit", car);
bool result = authorizationResult.IsAllowed();

// Resolves to `IVoter<TSubject, TUser>` voter instances using the configured (or default) access decision strategy.
IAuthorizationResult<Car> authorizationResult = authorizationChecker.GetAuthorizationResult("edit", car, user);
bool result = authorizationResult.IsAllowed();

// Resolves to `IVoter<TSubject>` voter instances using the provided (`AccessDecisionStrategy.Unanimous`) access decision strategy.
IAuthorizationResult<Car> authorizationResult = authorizationChecker.GetAuthorizationResult("edit", car, AccessDecisionStrategy.Unanimous);
bool result = authorizationResult.IsAllowed();

// Resolves to `IVoter<TSubject, TUser>` voter instances using the provided (`AccessDecisionStrategy.Unanimous`) access decision strategy.
IAuthorizationResult<Car> authorizationResult = authorizationChecker.GetAuthorizationResult("edit", car, user, AccessDecisionStrategy.Unanimous);
bool result = authorizationResult.IsAllowed();