How to add claims in ASP.NET Identity

The correct place to add claims, assuming you are using the ASP.NET MVC 5 project template is in ApplicationUser.cs. Just search for Add custom user claims here. This will lead you to the GenerateUserIdentityAsync method. This is the method that is called when the ASP.NET Identity system has retrieved an ApplicationUser object and needs to turn that into a ClaimsIdentity. You will see this line of code:

// Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);

After that is the comment:

// Add custom user claims here

And finally, it returns the identity:

return userIdentity;

So if you wanted to add a custom claim, your GenerateUserIdentityAsync might look something like:

// Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);

// Add custom user claims here
userIdentity.AddClaim(new Claim("myCustomClaim", "value of claim"));

return userIdentity;

Perhaps the following article can help:

var claims = new List<Claim>();
claims.Add(new Claim(ClaimTypes.Name, "Brock"));
claims.Add(new Claim(ClaimTypes.Email, "[email protected]"));
var id = new ClaimsIdentity(claims,DefaultAuthenticationTypes.ApplicationCookie);

var ctx = Request.GetOwinContext();
var authenticationManager = ctx.Authentication;
authenticationManager.SignIn(id);

you can do the following in WEB API C #

var identity = new ClaimsIdentity(context.Options.AuthenticationType);          
        foreach(var Rol in roles)
        {
            identity.AddClaim(new Claim(ClaimTypes.Role, Rol));
        }
        identity.AddClaim(new Claim(ClaimTypes.Name, context.UserName));
        identity.AddClaim(new Claim(ClaimTypes.Email, user.Correo));
        identity.AddClaim(new Claim(ClaimTypes.MobilePhone, user.Celular));
        identity.AddClaim(new Claim("FullName", user.FullName));
        identity.AddClaim(new Claim("Empresa", user.Empresa));
        identity.AddClaim(new Claim("ConnectionStringsName", user.ConnectionStringsName));

....

If you want to add custom claims at the time of registration then this code will work:

            var user = new ApplicationUser
            {
                UserName = model.UserName,
                Email = model.Email
            };
            var result = await UserManager.CreateAsync(user, model.Password);
            // Associate the role with the new user 
            await UserManager.AddToRoleAsync(user.Id, model.UserRole);
            // Create customized claim 
            await UserManager.AddClaimAsync(user.Id, new Claim("newCustomClaim", "claimValue"));
            if (result.Succeeded)
            {...etc