Writing a custom IUserPasswordStore and SignInManager.PasswordSignInAsync in Identity 2.1 - asp.net-identity-2

Question

Building a custom IUserPasswordStore to connect to a legacy system's username/password table. The password is hashed with custom code in the table so I need to write custom code for PasswordSignInAsync.
Do I need to override PasswordSignInAsync or is there a method I can provide that just does the hashing of the password? If I do override the entire PasswordSignInAsync is there sample code somewhere showing me what needs to be done in the method?

Answer 1

That was easier than I thought.
Override CheckPasswordAsync in UserManager.

Answer 2

For someone who wants to see the complete setup in .NET 6, this is how it looks like:
Step 1:
Add CustomUserManager to override CheckPasswordAsync:
using Microsoft.AspNetCore.Identity;
using Microsoft.Extensions.Options;
public class CustomUserManager<TUser> : UserManager<TUser> where TUser : IdentityUser
{
public CustomUserManager(IUserStore<TUser> store, IOptions<IdentityOptions> optionsAccessor,
IPasswordHasher<TUser> passwordHasher, IEnumerable<IUserValidator<TUser>> userValidators,
IEnumerable<IPasswordValidator<TUser>> passwordValidators, ILookupNormalizer keyNormalizer,
IdentityErrorDescriber errors, IServiceProvider services, ILogger<UserManager<TUser>> logger)
: base(store, optionsAccessor, passwordHasher, userValidators, passwordValidators, keyNormalizer,
errors, services, logger)
{
}
// THIS IS ONLY CALLED FOR USERS STORED IN YOUR IDENTITY DATABASE
public override Task<bool> CheckPasswordAsync(TUser user, string password)
{
// Add custom check using user.UserName and password
return Task.FromResult(true); // Replace this with your custom check
}
}
Step 2:
Register it in your Program.cs
builder.Services
.AddDefaultIdentity<ApplicationUser>(options =>
{
options.SignIn.RequireConfirmedAccount = false;
})
.AddUserManager<CustomUserManager<ApplicationUser>>() <----- THIS GUY
.AddEntityFrameworkStores<ApplicationDbContext>();
ApplicationUser and ApplicationDbContext look like this:
public class ApplicationUser : IdentityUser
{
}
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
: base(options)
{
}
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
// Customize the ASP.NET Identity model and override the defaults if needed.
// For example, you can rename the ASP.NET Identity table names and more.
// Add your customizations after calling base.OnModelCreating(builder);
}
}
Step 3:
Try to Login using this:
var result = await _signInManager.PasswordSignInAsync("SomeUserNameInYourIdentityDatabase", "SomePassword", isPersistent: true, lockoutOnFailure: false);