Files

297 lines
14 KiB
C#

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.RateLimiting;
using MongoDB.Driver;
using QuestionsApi.Models;
using QuestionsApi.Services;
using System.Security.Claims;
using System.Security.Cryptography;
namespace QuestionsApi.Controllers;
[ApiController]
[Route("api/Auth/external")]
public sealed class ExternalAuthController(
IEnumerable<IExternalAuthProvider> providerServices,
ExternalIdentityStore identities,
ExternalAuthTransactionStore transactions,
AuthUserStore users,
JwtTokenService tokens,
LegalPolicy legal,
IConfiguration configuration,
ILogger<ExternalAuthController> logger) : ControllerBase
{
private readonly Dictionary<string, IExternalAuthProvider> _providers = providerServices
.ToDictionary(value => value.Id, StringComparer.OrdinalIgnoreCase);
[HttpGet("providers")]
[AllowAnonymous]
public IActionResult Providers() => Ok(new
{
providers = _providers.Values.Where(value => value.IsConfigured)
.OrderBy(value => value.DisplayName)
.Select(value => new { id = value.Id, name = value.DisplayName })
});
[HttpPost("{provider}/start")]
[AllowAnonymous]
[EnableRateLimiting("external-start")]
public async Task<IActionResult> Start(string provider, ExternalAuthStartRequest? request)
{
if (!TryProvider(provider, out var service)) return NotFound(new { message = "Provider is unavailable." });
var purpose = (request?.Purpose ?? "login").Trim().ToLowerInvariant();
if (purpose is not ("login" or "link")) return BadRequest(new { message = "Purpose must be login or link." });
string? userId = null;
if (purpose == "link")
{
userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
if (string.IsNullOrWhiteSpace(userId)) return Unauthorized();
if (await identities.GetForUserAsync(userId, service.Id) is not null)
return Conflict(new { message = $"This account is already connected to {service.DisplayName}." });
}
var now = DateTime.UtcNow;
var lifetime = Math.Clamp(configuration.GetValue("ExternalAuth:TransactionTtlMinutes", 5), 2, 15);
var transaction = new ExternalAuthTransaction
{
Id = Base64Url(RandomNumberGenerator.GetBytes(32)),
Provider = service.Id,
Purpose = purpose,
UserId = userId,
Nonce = GoogleExternalAuthProvider.NewNonce(),
CodeVerifier = GoogleExternalAuthProvider.NewVerifier(),
CreatedUtc = now,
ExpiresUtc = now.AddMinutes(lifetime)
};
await transactions.CreateAsync(transaction);
return Ok(new
{
transactionId = transaction.Id,
provider = service.Id,
authUrl = service.BuildAuthorizationUrl(transaction),
transaction.ExpiresUtc
});
}
[HttpGet("{provider}/callback")]
[AllowAnonymous]
[EnableRateLimiting("external-complete")]
public async Task<IActionResult> Callback(
string provider,
[FromQuery] string? transactionId,
[FromQuery] string? state,
CancellationToken cancellationToken)
{
if (!TryProvider(provider, out var service))
return CallbackPage(false, "External sign-in", "This provider is unavailable.");
var callbackTransactionId = string.IsNullOrWhiteSpace(transactionId) ? state : transactionId;
var transaction = await ActiveTransactionAsync(callbackTransactionId ?? "");
if (transaction is null || transaction.Status != "pending" || transaction.Provider != service.Id)
return CallbackPage(false, service.DisplayName, "This sign-in request has expired. Return to RanaZe and try again.");
var claims = await service.VerifyCallbackAsync(Request.Query, transaction, cancellationToken);
if (claims is null)
{
logger.LogWarning("{Provider} external identity verification failed", service.Id);
return CallbackPage(false, service.DisplayName, $"{service.DisplayName} could not verify this sign-in.");
}
if (transaction.Purpose == "link")
{
if (string.IsNullOrWhiteSpace(transaction.UserId) ||
!await identities.TryLinkAsync(transaction.UserId, service.Id, claims) ||
!await transactions.MarkVerifiedAsync(transaction.Id, claims, "linked", transaction.UserId))
return CallbackPage(false, service.DisplayName,
$"That {service.DisplayName} identity is already connected to another account.");
return CallbackPage(true, service.DisplayName, $"{service.DisplayName} is now connected to your RanaZe account.");
}
var identity = await identities.GetAsync(service.Id, claims.Subject);
var user = identity is null ? null : await users.GetByIdAsync(identity.UserId);
var status = user is null ? "requires_account" : "complete";
if (!await transactions.MarkVerifiedAsync(transaction.Id, claims, status, user?.Id))
return CallbackPage(false, service.DisplayName, "This sign-in request has already been used.");
if (user is not null)
{
await identities.TouchAsync(identity!.Id);
user.RefreshToken = JwtTokenService.NewRefreshToken();
user.RefreshTokenExpiry = DateTime.UtcNow.AddDays(7);
await users.UpdateAsync(user);
}
return CallbackPage(true, service.DisplayName,
$"{service.DisplayName} verified your identity. You can return to RanaZe.");
}
[HttpGet("{provider}/status/{transactionId}")]
[AllowAnonymous]
[EnableRateLimiting("external-poll")]
public async Task<IActionResult> Status(string provider, string transactionId)
{
Response.Headers.CacheControl = "no-store";
if (!TryProvider(provider, out var service)) return NotFound(new { message = "Provider is unavailable." });
var transaction = await ActiveTransactionAsync(transactionId);
if (transaction is null || transaction.Provider != service.Id)
return NotFound(new { message = $"{service.DisplayName} sign-in expired." });
if (transaction.Status == "requires_account")
return Ok(new
{
status = transaction.Status,
provider = service.Id,
providerName = service.DisplayName,
email = transaction.EmailVerified ? transaction.ProviderEmail : null,
emailVerified = transaction.EmailVerified
});
if (transaction.Status is "pending" or "linked" or "failed")
return Ok(new { status = transaction.Status, provider = service.Id, message = transaction.Error });
if (transaction.Status != "complete" || string.IsNullOrWhiteSpace(transaction.UserId))
return Conflict(new { message = $"{service.DisplayName} sign-in is incomplete." });
var user = await users.GetByIdAsync(transaction.UserId);
if (user is null || transaction.Subject is null ||
await identities.GetAsync(service.Id, transaction.Subject) is not { } identity ||
identity.UserId != user.Id)
return Conflict(new { message = $"{service.DisplayName} account link is no longer valid." });
if (string.IsNullOrWhiteSpace(user.RefreshToken) || user.RefreshTokenExpiry <= DateTime.UtcNow)
{
user.RefreshToken = JwtTokenService.NewRefreshToken();
user.RefreshTokenExpiry = DateTime.UtcNow.AddDays(7);
await users.UpdateAsync(user);
}
var (accessToken, jti, expiresUtc) = tokens.Generate(user);
return Ok(new
{
status = "complete",
accessToken,
refreshToken = user.RefreshToken,
user.Username,
user.Role,
jti,
exp = expiresUtc,
legal = legal.Status(user)
});
}
[HttpPost("{provider}/complete")]
[AllowAnonymous]
[EnableRateLimiting("external-complete")]
public async Task<IActionResult> Complete(string provider, CompleteExternalAuthRequest request)
{
if (!TryProvider(provider, out var service)) return NotFound(new { message = "Provider is unavailable." });
var transaction = await ActiveTransactionAsync(request.TransactionId);
if (transaction?.Status == "complete") return Ok(new { status = "complete" });
if (transaction is null || transaction.Provider != service.Id || transaction.Status != "requires_account" ||
string.IsNullOrWhiteSpace(transaction.Subject))
return BadRequest(new { message = $"{service.DisplayName} sign-in is not ready or has expired." });
if (await identities.GetAsync(service.Id, transaction.Subject) is not null)
return Conflict(new { message = $"That {service.DisplayName} identity is already connected." });
var claims = new ExternalProviderClaims(
transaction.Subject, transaction.ProviderEmail, transaction.EmailVerified);
AuthUser user;
var createdUser = false;
if (request.Action == "create")
{
if (!request.AcceptLegal)
return BadRequest(new { message = "You must accept the current legal agreements." });
var username = request.Username.Trim();
var email = service.Id == ExternalAuthProviders.Google
? AuthValidation.NormalizeEmail(transaction.ProviderEmail ?? "")
: AuthValidation.NormalizeEmail(request.Email ?? "");
if (service.Id == ExternalAuthProviders.Google && !transaction.EmailVerified)
return BadRequest(new { message = "Google did not provide a verified email address." });
if (AuthValidation.ValidateNewAccount(username, email, request.Password) is { } validation)
return BadRequest(new { message = validation });
if (await users.GetByUsernameAsync(username) is not null)
return Conflict(new { message = "Username already exists." });
if (await users.EmailExistsAsync(email))
return Conflict(new
{
message = "That email already belongs to a RanaZe account. Link the existing account with its password."
});
user = new AuthUser
{
Username = username,
Email = email,
NormalizedEmail = email,
PasswordHash = BCrypt.Net.BCrypt.HashPassword(request.Password),
Role = "USER",
CreatedUtc = DateTime.UtcNow
};
legal.Accept(user, $"{service.Id}_registration");
try
{
await users.CreateAsync(user);
createdUser = true;
}
catch (MongoWriteException exception) when (
exception.WriteError.Category == ServerErrorCategory.DuplicateKey)
{
return Conflict(new { message = "That username or email is already in use." });
}
}
else if (request.Action == "link")
{
var candidates = await users.GetByLoginCandidatesAsync(request.Username);
user = candidates.FirstOrDefault(candidate =>
BCrypt.Net.BCrypt.Verify(request.Password, candidate.PasswordHash))!;
if (user is null) return Unauthorized(new { message = "The account credentials are incorrect." });
if (await identities.GetForUserAsync(user.Id, service.Id) is not null)
return Conflict(new { message = $"That RanaZe account already has a {service.DisplayName} identity." });
}
else
{
return BadRequest(new { message = "Action must be create or link." });
}
if (!await identities.TryLinkAsync(user.Id, service.Id, claims))
{
if (createdUser) await users.DeleteAsync(user.Id);
return Conflict(new { message = $"That {service.DisplayName} identity is already connected." });
}
if (!await transactions.MarkCompleteAsync(transaction.Id, transaction.Subject, user.Id))
{
if (createdUser)
{
await identities.Collection.DeleteManyAsync(value => value.UserId == user.Id);
await users.DeleteAsync(user.Id);
}
return Conflict(new { message = "This external sign-in was already completed." });
}
return Ok(new { status = "complete" });
}
private bool TryProvider(string provider, out IExternalAuthProvider service)
{
if (_providers.TryGetValue(provider.Trim(), out service!) && service.IsConfigured) return true;
service = null!;
return false;
}
private async Task<ExternalAuthTransaction?> ActiveTransactionAsync(string id)
{
if (string.IsNullOrWhiteSpace(id) || id.Length > 128) return null;
var transaction = await transactions.GetAsync(id);
return transaction is not null && transaction.ExpiresUtc > DateTime.UtcNow ? transaction : null;
}
private ContentResult CallbackPage(bool success, string provider, string message)
{
Response.Headers.CacheControl = "no-store";
Response.Headers.ContentSecurityPolicy = "default-src 'none'; style-src 'unsafe-inline'; script-src 'unsafe-inline'";
Response.Headers.XFrameOptions = "DENY";
Response.Headers["Referrer-Policy"] = "no-referrer";
var color = success ? "#22c55e" : "#ef4444";
var safeProvider = System.Net.WebUtility.HtmlEncode(provider);
var safeMessage = System.Net.WebUtility.HtmlEncode(message);
var html = $$"""
<!doctype html><html><head><meta charset="utf-8"><meta name="viewport" content="width=device-width">
<title>RanaZe {{safeProvider}} sign-in</title><style>body{font-family:system-ui;background:#081324;color:#f8fafc;display:grid;place-items:center;min-height:100vh;margin:0}.card{max-width:34rem;padding:2rem;border:1px solid #33415d;border-radius:8px}h1{color:{{color}};font-size:1.4rem}</style></head>
<body><main class="card"><h1>{{safeProvider}} sign-in {{(success ? "complete" : "failed")}}</h1><p>{{safeMessage}}</p></main>
<script>if(window.opener){setTimeout(()=>window.close(),1200);}</script></body></html>
""";
return Content(html, "text/html; charset=utf-8");
}
private static string Base64Url(byte[] bytes) =>
Convert.ToBase64String(bytes).TrimEnd('=').Replace('+', '-').Replace('/', '_');
}