Dotnet-WebAPI/AppContext/AppContext.cs

using System.Security.Cryptography;
using AppContext.Entities;
using Microsoft.AspNetCore.Cryptography.KeyDerivation;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;

namespace AppContext;

public class AppContext : DbContext
{
    public DbSet<UserEntity> Users { get; init; }
    public DbSet<TacticEntity> Tactics { get; init; }
    public DbSet<TeamEntity> Teams { get; init; }
    public DbSet<MemberEntity> Members { get; init; }
    public DbSet<TacticStepEntity> TacticSteps { get; set; }

    public AppContext()
    {
        
    }

    public AppContext(DbContextOptions<AppContext> options) : base(options)
    {
        
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        base.OnConfiguring(optionsBuilder);
        if (optionsBuilder.IsConfigured)
        {
            return;
        }
        
        var pgsqliteDsn = Environment.GetEnvironmentVariable("PGSQL_DSN");

        if (pgsqliteDsn != null)
        {
            optionsBuilder.UseNpgsql(pgsqliteDsn);
        }
        else
        {
            optionsBuilder.UseSqlite("Data Source=database.db");
        }

    }

    protected override void OnModelCreating(ModelBuilder builder)
    {
        base.OnModelCreating(builder);
        builder.Entity<UserEntity>()
            .Property(e => e.Password)
            .HasConversion(
                v => HashString(v),
                v => v
            );

        builder.Entity<MemberEntity>()
            .HasKey("UserId", "TeamId");
    }

    private static string HashString(string str)
    {
        byte[] salt = RandomNumberGenerator.GetBytes(128 / 8);
        return Convert.ToBase64String(KeyDerivation.Pbkdf2(
            password: str,
            salt,
            prf: KeyDerivationPrf.HMACSHA256,
            iterationCount: 50000,
            numBytesRequested: 256 / 8
        ));
    }
}