AuthorizeView Policy: Blazor Page not displaying

Question

IdentityServer returns AuthenticationScheme: Bearer was forbidden.

I checked the AccessToken and it contains the scope "account.read" however blazor does not display the page

Am I missing something?

Startup.cs

        services.AddAuthorization(options =>
        {
            options.AddPolicy("Account", policy => policy.RequireClaim(JwtClaimTypes.Scope, "account"));
            options.AddPolicy("AccountWrite", policy => policy.RequireClaim(JwtClaimTypes.Scope, "account", "account.write"));
            options.AddPolicy("AccountRead", policy => policy.RequireClaim(JwtClaimTypes.Scope, "account", "account.read")); 
        });

Blazor Page

<AuthorizeView> <p> you are logged in </p> <AuthorizeView>
<AuthorizeView Policy="AccountRead">
<p> you have account.read access </p>
</AuthorizeView>

Answer 1

The issue is due to the current lack of support for Blazor to read claims the are sent as arrays.

e.g. user: ["c","r","u","d"]

Can't be read.

To rectify this you need to add ClaimsPrincipalFactory.

e.g.

public class ArrayClaimsPrincipalFactory<TAccount> : AccountClaimsPrincipalFactory<TAccount> where TAccount : RemoteUserAccount
{
    public ArrayClaimsPrincipalFactory(IAccessTokenProviderAccessor accessor)
    : base(accessor)
    { }


    // when a user belongs to multiple roles, IS4 returns a single claim with a serialised array of values
    // this class improves the original factory by deserializing the claims in the correct way
    public async override ValueTask<ClaimsPrincipal> CreateUserAsync(TAccount account, RemoteAuthenticationUserOptions options)
    {
        var user = await base.CreateUserAsync(account, options);

        var claimsIdentity = (ClaimsIdentity)user.Identity;

        if (account != null)
        {
            foreach (var kvp in account.AdditionalProperties)
            {
                var name = kvp.Key;
                var value = kvp.Value;
                if (value != null &&
                    (value is JsonElement element && element.ValueKind == JsonValueKind.Array))
                {
                    claimsIdentity.RemoveClaim(claimsIdentity.FindFirst(kvp.Key));

                    var claims = element.EnumerateArray()
                        .Select(x => new Claim(kvp.Key, x.ToString()));

                    claimsIdentity.AddClaims(claims);
                }
            }
        }

        return user;
    }
}

Then register this in your program/startup(depending on if you use .core hosted or not)like so:

builder.Services.AddOidcAuthentication(options =>
        {
            builder.Configuration.Bind("oidc", options.ProviderOptions);
        })
        .AddAccountClaimsPrincipalFactory<ArrayClaimsPrincipalFactory<RemoteUserAccount>>();