Umbraco-CMS/src/Umbraco.Web/Security/IBackOfficeUserPasswordChecker.cs

using System.Threading.Tasks;
using Umbraco.Core.Models.Identity;

namespace Umbraco.Web.Security
{
    /// <summary>
    /// Used by the BackOfficeUserManager to check the username/password which allows for developers to more easily
    /// set the logic for this procedure.
    /// </summary>
    public interface IBackOfficeUserPasswordChecker
    {
        /// <summary>
        /// Checks a password for a user
        /// </summary>
        /// <param name="user"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        /// <remarks>
        /// This will allow a developer to auto-link a local account which is required if the user queried doesn't exist locally.
        /// The user parameter will always contain the username, if the user doesn't exist locally, the other properties will not be filled in.
        /// A developer can then create a local account by filling in the properties and using UserManager.CreateAsync
        /// </remarks>
        Task<BackOfficeUserPasswordCheckerResult> CheckPasswordAsync(BackOfficeIdentityUser user, string password);
    }
}