问题

I am building a WebAPI and I have some metadata columns in my model like InsertUser and UpdateUser. I am using Microsoft.Identity to authenticate users like so

services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
  .AddMicrosoftIdentityWebApi(_configuration.GetSection("AzureAd"))
  .EnableTokenAcquisitionToCallDownstreamApi()
  .AddMicrosoftGraph(_configuration.GetSection("MicrosoftGraph"))
  .AddInMemoryTokenCaches();

I want to make a call to Graph after successful authentication and store the DisplayName somewhere so I can use it in my DataContext in SaveChanges. How can I achieve this?

DataContext.cs

public override int SaveChanges()
{
    var entries = ChangeTracker
        .Entries()
        .Where(e => e.Entity is BaseEntity && (
                e.State == EntityState.Added
                || e.State == EntityState.Modified));

    foreach (var entityEntry in entries)
    {
        ((BaseEntity)entityEntry.Entity).UpdateTimestamp = DateTime.UtcNow;
        ((BaseEntity)entityEntry.Entity).UpdateUser = "System"; //Change to logged in user

        if (entityEntry.State == EntityState.Added)
        {
            ((BaseEntity)entityEntry.Entity).InsertTimestamp = DateTime.UtcNow;
            ((BaseEntity)entityEntry.Entity).InsertUser = "System"; //Change to logged in user
        }
    }

    return base.SaveChanges();
}

I tried following some tutorials and have tried storing it into the ClaimsIdentity

Startup.cs

services.Configure<JwtBearerOptions>(JwtBearerDefaults.AuthenticationScheme, options =>
{
    options.Events ??= new JwtBearerEvents
    {
        OnTokenValidated = async context =>
        {
            var userProfileService = context.HttpContext.RequestServices.GetRequiredService<IUserProfile>();
            var user = await userProfileService.RetrieveUserProfileAsync();

            var identity = context.Principal.Identity as ClaimsIdentity;
            if (identity != null)
            {
                identity.AddClaim(new Claim("DisplayName", user.DisplayName));
            }
        }
    };
});
services.AddScoped<IUserProfile, UserProfile>();

UserProfile.cs

using Microsoft.Graph;

namespace WebAPI.Services
{
    public interface IUserProfile
    {
        Task<User> RetrieveUserProfileAsync();
    }
    public class UserProfile : IUserProfile
    {
        private readonly GraphServiceClient _graphServiceClient;

        public UserProfile(GraphServiceClient graphServiceClient)
        {
            _graphServiceClient = graphServiceClient;
        }

        public async Task<User> RetrieveUserProfileAsync()
        {
            var user = await _graphServiceClient.Me.Request().GetAsync();
            return user;
        }
    }
}

And to test I've added this when an API call is made

var claimsIdentity = _httpContextAccessor.HttpContext?.User?.Identity as ClaimsIdentity;
var userProfileDisplayName = claimsIdentity?.FindFirst("DisplayName")?.Value;
Console.WriteLine($"User: {userProfileDisplayName}");

But it prints just User: . What am I doing wrong and how could I fix it?

services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
  .AddMicrosoftIdentityWebApi(_configuration.GetSection("AzureAd"))
  .EnableTokenAcquisitionToCallDownstreamApi()
  .AddMicrosoftGraph(_configuration.GetSection("MicrosoftGraph"))
  .AddInMemoryTokenCaches();

public override int SaveChanges()
{
    var entries = ChangeTracker
        .Entries()
        .Where(e => e.Entity is BaseEntity && (
                e.State == EntityState.Added
                || e.State == EntityState.Modified));

    foreach (var entityEntry in entries)
    {
        ((BaseEntity)entityEntry.Entity).UpdateTimestamp = DateTime.UtcNow;
        ((BaseEntity)entityEntry.Entity).UpdateUser = "System"; //Change to logged in user

        if (entityEntry.State == EntityState.Added)
        {
            ((BaseEntity)entityEntry.Entity).InsertTimestamp = DateTime.UtcNow;
            ((BaseEntity)entityEntry.Entity).InsertUser = "System"; //Change to logged in user
        }
    }

    return base.SaveChanges();
}

services.Configure<JwtBearerOptions>(JwtBearerDefaults.AuthenticationScheme, options =>
{
    options.Events ??= new JwtBearerEvents
    {
        OnTokenValidated = async context =>
        {
            var userProfileService = context.HttpContext.RequestServices.GetRequiredService<IUserProfile>();
            var user = await userProfileService.RetrieveUserProfileAsync();

            var identity = context.Principal.Identity as ClaimsIdentity;
            if (identity != null)
            {
                identity.AddClaim(new Claim("DisplayName", user.DisplayName));
            }
        }
    };
});
services.AddScoped<IUserProfile, UserProfile>();

using Microsoft.Graph;

namespace WebAPI.Services
{
    public interface IUserProfile
    {
        Task<User> RetrieveUserProfileAsync();
    }
    public class UserProfile : IUserProfile
    {
        private readonly GraphServiceClient _graphServiceClient;

        public UserProfile(GraphServiceClient graphServiceClient)
        {
            _graphServiceClient = graphServiceClient;
        }

        public async Task<User> RetrieveUserProfileAsync()
        {
            var user = await _graphServiceClient.Me.Request().GetAsync();
            return user;
        }
    }
}

var claimsIdentity = _httpContextAccessor.HttpContext?.User?.Identity as ClaimsIdentity;
var userProfileDisplayName = claimsIdentity?.FindFirst("DisplayName")?.Value;
Console.WriteLine($"User: {userProfileDisplayName}");

答案1

得分: 0

不要紧，我找到了问题。在 **Startup.cs** 的 **OnTokenValidated** 方法中，我添加了这一行代码以覆盖来自令牌声明的用户上下文，现在它可以正常工作了。

```C#
OnTokenValidated = async context =>
{
  // 先前的代码

  var identity = context.Principal.Identity as ClaimsIdentity;
  context.HttpContext.User = new ClaimsPrincipal(identity) ?? context.HttpContext.User;

  // 其余的代码
}

所以在我的 DataContext.cs 中，我可以这样存储显示名称：

var currentUserDisplayName = _httpContextAccessor.HttpContext?.User?.FindFirst("name")?.Value ?? "System";

<details>
<summary>英文:</summary>

Nevermind, I found the issue. In **Startup.cs**, in **OnTokenValidated** I added this line to overwrite the User context from the token claims and it works now.

```C#
OnTokenValidated = async context =&gt;
{
  // Prior Code

  var identity = context.Principal.Identity as ClaimsIdentity;
  context.HttpContext.User = new ClaimsPrincipal(identity) ?? context.HttpContext.User;

  // Rest of the Code
}

So in my DataContext.cs I can store the display name like so

var currentUserDisplayName = _httpContextAccessor.HttpContext?.User?.FindFirst("name")?.Value ?? "System";