aswi20220x00-gitlab/Backend/Core/Authentication/JwtUtils.cs @ c349bab3

using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Text;
using Core.Entities;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Options;
using Microsoft.IdentityModel.Tokens;

namespace Core.Authentication;

public interface IJwtUtils
{
    public string GenerateJwtToken(User user, DateTime? expiration = null);
    public Guid? ValidateJwtToken(string token);
}

public class JwtUtils : IJwtUtils
{
    private const int EXPIRATION_SECONDS = 8 * 60 * 60; // 8 hod

    private readonly JwtConfig _jwtConfig;
    private readonly TokenValidationParameters _tokenValidationParameters;

    public JwtUtils(IOptions<JwtConfig> jwtConfig, TokenValidationParameters tokenValidationParameters)
    {
        _jwtConfig = jwtConfig.Value;
        _tokenValidationParameters = tokenValidationParameters;
    }

    public static TokenValidationParameters GetTokenValidationParameters(ConfigurationManager configuration)
    {
        return new TokenValidationParameters
        {
            RequireExpirationTime = true,
            ValidateIssuerSigningKey = false,
            IssuerSigningKey =
                new SymmetricSecurityKey(Encoding.UTF8.GetBytes(configuration["JwtConfig:Secret"])),
            ValidateIssuer = false,
            ValidIssuer = configuration["JwtConfig:Issuer"],
            ValidateAudience = false,
            ValidateLifetime = true
        };
    }


    public string GenerateJwtToken(User user, DateTime? expiration = null)
    {
        expiration ??= DateTime.Now.AddHours(10);

        var tokenHandler = new JwtSecurityTokenHandler();
        var key = Encoding.ASCII.GetBytes(_jwtConfig.Secret);
        var tokenDescriptor = new SecurityTokenDescriptor
        {
            Subject = new ClaimsIdentity(new[] {new Claim("id", user.Id.ToString())}),
            Expires = expiration,
            SigningCredentials =
                new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha256Signature)
        };
        var token = tokenHandler.CreateToken(tokenDescriptor);
        return tokenHandler.WriteToken(token);
    }

    public Guid? ValidateJwtToken(string? token)
    {
        if (token == null)
            return null;

        var tokenHandler = new JwtSecurityTokenHandler();
        var key = Encoding.ASCII.GetBytes(_jwtConfig.Secret);
        try
        {
            tokenHandler.ValidateToken(token, _tokenValidationParameters, out SecurityToken validatedToken);

            var jwtToken = (JwtSecurityToken) validatedToken;
            var userId = Guid.Parse(jwtToken.Claims.First(x => x.Type == "id").Value);

            // return user id from JWT token if validation successful
            return userId;
        }
        catch
        {
            // return null if validation fails
            return null;
        }
    }
}