Bearer Authentication policy for ASP.NET Core 5.0

BearerPolicyEvaluator.cs

public sealed class BearerPolicyEvaluator : IPolicyEvaluator
{
	private const string Scheme = "Bearer";

	public Task<AuthenticateResult> AuthenticateAsync(AuthorizationPolicy _, HttpContext context)
	{
		if (!context.Request.Headers.ContainsKey("Authorization"))
			return Task.FromResult(AuthenticateResult.Fail("No Authorization header found!"));

		string authHeader = context.Request.Headers["Authorization"];

		string bearerToken = authHeader?.Replace("Bearer ", string.Empty);

		if (!string.Equals(bearerToken, "authToken", StringComparison.Ordinal))
		{
			return Task.FromResult(AuthenticateResult.Fail("Invalid token"));
		}

		var claims = new[]
		{
			new Claim(ClaimTypes.NameIdentifier, "1000"),
			new Claim(ClaimTypes.Name, "Deepu Madhusoodanan")
		};

		var identity = new ClaimsIdentity(claims, Scheme);

		var principal = new ClaimsPrincipal(identity);

		var ticket = new AuthenticationTicket(principal, Scheme);

		var authenticateResult = AuthenticateResult.Success(ticket);

		return Task.FromResult(authenticateResult);
	}

	public Task<PolicyAuthorizationResult> AuthorizeAsync(AuthorizationPolicy _,
		AuthenticateResult authenticationResult, HttpContext context,
		object resource)
	{
		var authorizeResult = authenticationResult.Succeeded
			? PolicyAuthorizationResult.Success()
			: PolicyAuthorizationResult.Challenge();

		return Task.FromResult(authorizeResult);
	}
}