Webapi Response 500 Internal Server Error - asp.net-mvc

Question

I made an asp.net core web api and implemented some logic to register user.
But the issue is that whenever I call the controller from postman, it gives me 500 Internal Server Error.I also implemented an simple IActionResult to return welcome message, that also don't work. Here is my code.
[ApiController]
[Route("api/[controller]")]
public class AuthController : Controller
{
private readonly IAuthRepository _repo;
public AuthController(IAuthRepository repo)
{
_repo = repo;
}
[HttpPost("register")]
public async Task<IActionResult> Register([FromBody]CreateUserDTO createUserDto)
{
createUserDto.Username=createUserDto.Username.ToLower();
if(await _repo.UserExists(createUserDto.Username))
return BadRequest("User With This User Name Already Exists");
var userToCreate=new User
{
UserName=createUserDto.Username
};
var createdUser=await _repo.Register(userToCreate,createUserDto.Password);
return Ok("user registered");
}
[HttpGet]
public IActionResult Get()
{
var message="welcome message";
return Ok(message);
}
}
Looking to hear from you soon.
Thanks

Answer 1

I figured out the problem.
The problem was with my AuthRepository constructor where I wasn't specifying the public modifier.
Here is my AuthRepository code (working)
public class AuthRepository : IAuthRepository
{
private readonly ApplicationDatabase _db;
public AuthRepository(ApplicationDatabase db)
{
_db = db;
}
public async Task<User> Login(string username, string password)
{
var user=await _db.Users.Where(x=>x.UserName==username).FirstOrDefaultAsync();
if (user==null)
return null;
if(!verifyPasswordHash(password,user.PasswordHash,user.PasswordSalt))
return null;
return user;
}
private bool verifyPasswordHash(string password, byte[] passwordHash, byte[] passwordSalt)
{
using(var hmac=new System.Security.Cryptography.HMACSHA512(passwordSalt))
{
var computedPasswordHash=hmac.ComputeHash(System.Text.Encoding.UTF8.GetBytes(password));
for (int i = 0; i < computedPasswordHash.Length; i++)
{
if (computedPasswordHash[i]!=passwordHash[i])
{
return false;
}
}
}
return true;
}
public async Task<User> Register(User user, string password)
{
byte[] passwordHash,passwordSalt;
CreatePasswordHashSalt(password,out passwordHash,out passwordSalt);
user.PasswordHash=passwordHash;
user.PasswordSalt=passwordSalt;
await _db.Users.AddAsync(user);
_db.SaveChangesAsync();
return user;
}
private void CreatePasswordHashSalt(string password, out byte[] passwordHash, out byte[] passwordSalt)
{
using(var hmac=new System.Security.Cryptography.HMACSHA512())
{
passwordSalt=hmac.Key;
passwordHash=hmac.ComputeHash(System.Text.Encoding.UTF8.GetBytes(password));
}
}
public async Task<bool> UserExists(string username)
{
if(await _db.Users.AnyAsync(x=>x.UserName==username))
return true;
return false;
}
}