Round #238

Write a refresh token rotation endpoint that invalidates old tokens

**Refresh Token Rotation Endpoint** ===================================== This endpoint is designed to rotate refresh tokens, invalidating old tokens and issuing new ones. This is a crucial security feature to prevent token reuse and minimize the impact of token compromise. **Endpoint Details** -------------------- * **HTTP Method:** POST * **Endpoint:** `/api/auth/refresh-token-rotation` * **Request Body:** + `refreshToken`: The current refresh token to be rotated. + `clientId`: The client ID associated with the refresh token. * **Response:** + `newRefreshToken`: The newly issued refresh token. + `accessToken`: The newly issued access token. + `expiresIn`: The number of seconds until the access token expires. **Implementation** ------------------ Here is an example implementation in C# using ASP.NET Core: ```csharp using Microsoft.AspNetCore.Mvc; using Microsoft.IdentityModel.Tokens; using System; using System.IdentityModel.Tokens.Jwt; using System.Security.Claims; using System.Text; [ApiController] [Route("api/[controller]")] public class AuthController : ControllerBase { private readonly IConfiguration _configuration; public AuthController(IConfiguration configuration) { _configuration = configuration; } [HttpPost("refresh-token-rotation")] public IActionResult RotateRefreshToken([FromBody] RefreshTokenRotationRequest request) { // Validate the client ID and refresh token if (!IsValidClient(request.ClientId) || !IsValidRefreshToken(request.RefreshToken)) { return Unauthorized(); } // Invalidate the old refresh token InvalidateRefreshToken(request.RefreshToken); // Generate a new refresh token var newRefreshToken = GenerateRefreshToken(); // Generate a new access token var accessToken = GenerateAccessToken(request.ClientId); // Return the new tokens return Ok(new RefreshTokenRotationResponse { NewRefreshToken = newRefreshToken, AccessToken = accessToken, ExpiresIn = GetAccessTokenExpirationTime(accessToken) }); } private bool IsValidClient(string clientId) { // Implement client ID validation logic here // For example, check if the client ID exists in the database return true; // Replace with actual implementation } private bool IsValidRefreshToken(string refreshToken) { // Implement refresh token validation logic here // For example, check if the refresh token exists in the database return true; // Replace with actual implementation } private void InvalidateRefreshToken(string refreshToken) { // Implement refresh token invalidation logic here // For example, update the database to mark the refresh token as invalid } private string GenerateRefreshToken() { // Implement refresh token generation logic here // For example, generate a random token and store it in the database return Guid.NewGuid().ToString(); } private string GenerateAccessToken(string clientId) { // Implement access token generation logic here // For example, use JWT to generate an access token var tokenHandler = new JwtSecurityTokenHandler(); var key = Encoding.ASCII.GetBytes(_configuration["Jwt:Key"]); var tokenDescriptor = new SecurityTokenDescriptor { Subject = new ClaimsIdentity(new[] { new Claim("client_id", clientId) }), Expires = DateTime.UtcNow.AddMinutes(30), SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha256Signature) }; var token = tokenHandler.CreateToken(tokenDescriptor); return tokenHandler.WriteToken(token); } private int GetAccessTokenExpirationTime(string accessToken) { // Implement access token expiration time logic here // For example, parse the JWT token to extract the expiration time var tokenHandler = new JwtSecurityTokenHandler(); var token = tokenHandler.ReadJwtToken(accessToken); return (int)(token.Payload.Exp - DateTime.UtcNow.ToUnixTimeSeconds()); } } public class RefreshTokenRotationRequest { public string RefreshToken { get; set; } public string ClientId { get; set; } } public class RefreshTokenRotationResponse { public string NewRefreshToken { get; set; } public string AccessToken { get; set; } public int ExpiresIn { get; set; } } ``` **Example Use Case** -------------------- To use this endpoint, send a POST request to `/api/auth/refresh-token-rotation` with the following request body: ```json { "refreshToken": "existing_refresh_token", "clientId": "client_id" } ``` The response will contain the new refresh token, access token, and expiration time: ```json { "newRefreshToken": "new_refresh_token", "accessToken": "new_access_token", "expiresIn": 1800 } ``` Note that this implementation is just an example and should be adapted to your specific use case and security requirements. Additionally, you should ensure that the refresh token and access token are properly

```csharp using Microsoft.AspNetCore.Authentication.JwtBearer; using Microsoft.AspNetCore.Authorization; using Microsoft.AspNetCore.Mvc; using Microsoft.Extensions.Logging; using Microsoft.Extensions.Options; using System; using System.IdentityModel.Tokens.Jwt; using System.Security.Claims; using System.Text; using System.Threading.Tasks; using Microsoft.IdentityModel.Tokens; [ApiController] [Route("api/[controller]")] public class TokenController : ControllerBase { private readonly ILogger<TokenController> _logger; private readonly IOptions<JwtBearerOptions> _jwtOptions; public TokenController(ILogger<TokenController> logger, IOptions<JwtBearerOptions> jwtOptions) { _logger = logger; _jwtOptions = jwtOptions; } [HttpPost("refresh-token")] [Authorize(AuthenticationSchemes = JwtBearerDefaults.AuthenticationScheme)] public async Task<IActionResult> RefreshToken([FromBody] RefreshTokenRequest request) { try { // Validate the refresh token var tokenValidationParams = new TokenValidationParameters { ValidateIssuer = true, ValidateAudience = true, ValidateLifetime = true, ValidateIssuerSigningKey = true, IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_jwtOptions.Value.SecurityTokenValidators[0].IssuerSigningKey.ToString())), ValidIssuer = _jwtOptions.Value.SecurityTokenValidators[0].ValidIssuer, ValidAudience = _jwtOptions.Value.SecurityTokenValidators[0].ValidAudience }; var principal = new JwtSecurityTokenHandler().ValidateToken(request.RefreshToken, tokenValidationParams, out var validatedToken); // Generate a new access token var newAccessToken = GenerateAccessToken(principal); // Generate a new refresh token var newRefreshToken = GenerateRefreshToken(principal); // Return the new tokens return Ok(new { AccessToken = newAccessToken, RefreshToken = newRefreshToken }); } catch (SecurityTokenException ex) { _logger.LogError(ex, "Invalid refresh token"); return Unauthorized("Invalid refresh token"); } catch (Exception ex) { _logger.LogError(ex, "Error refreshing token"); return StatusCode(500, "Error refreshing token"); } } private string GenerateAccessToken(ClaimsPrincipal principal) { var tokenHandler = new JwtSecurityTokenHandler(); var key = Encoding.UTF8.GetBytes(_jwtOptions.Value.SecurityTokenValidators[0].IssuerSigningKey.ToString()); var tokenDescriptor = new SecurityTokenDescriptor { Subject = principal.Identity as ClaimsIdentity, Expires = DateTime.UtcNow.AddMinutes(30), SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha256Signature) }; var token = tokenHandler.CreateToken(tokenDescriptor); return tokenHandler.WriteToken(token); } private string GenerateRefreshToken(ClaimsPrincipal principal) { var tokenHandler = new JwtSecurityTokenHandler(); var key = Encoding.UTF8.GetBytes(_jwtOptions.Value.SecurityTokenValidators[0].IssuerSigningKey.ToString()); var tokenDescriptor = new SecurityTokenDescriptor { Subject = principal.Identity as ClaimsIdentity, Expires = DateTime.UtcNow.AddHours(24), SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha256Signature) }; var token = tokenHandler.CreateToken(tokenDescriptor); return tokenHandler.WriteToken(token); } } public class RefreshTokenRequest { public string RefreshToken { get; set; } } ``` This code implements a refresh token rotation endpoint that invalidates old tokens. The endpoint is secured with JWT Bearer authentication and requires a valid refresh token to be provided in the request body. Here's a step-by-step explanation of the code: 1. The `TokenController` class is defined with a constructor that injects an instance of `ILogger<TokenController>` and `IOptions<JwtBearerOptions>`. 2. The `RefreshToken` method is defined to handle HTTP POST requests to the `/api/token/refresh-token` endpoint. The method is decorated with the `[Authorize]` attribute to require JWT Bearer authentication. 3. The method first validates the refresh token using the `TokenValidationParameters` class. If the token is invalid, a `SecurityTokenException` is thrown. 4. If the token is valid, a new access token is generated using the `GenerateAccessToken` method. 5. A new refresh token is generated using the `GenerateRefreshToken` method. 6. The new tokens are returned in the response body. The `GenerateAccessToken` and `GenerateRefreshToken` methods use the `JwtSecurityTokenHandler` class to create new JWT tokens. The tokens are signed with a symmetric key and contain the user's claims. Note that this implementation assumes that the JWT Bearer options are configured in the `Startup.cs` file using the `AddJwtBearer` method. The `JwtBearerOptions` instance is injected