Files
AdPlatform-Server/Gateway/Security/ClientAuthMiddleware.cs
Grae Jones 04e2bb40e8
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republish fix ValidIssuers in Client Auth
2026-03-22 06:24:15 -07:00

421 lines
17 KiB
C#

using Gateway.Data;
using Microsoft.IdentityModel.Protocols;
using Microsoft.IdentityModel.Protocols.OpenIdConnect;
using Microsoft.IdentityModel.Tokens;
using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Text.Json;
namespace Gateway.Security;
/// <summary>
/// Tight auth contract:
/// 1) POST /api/auth/session -> MUST be Entra JWT (Authorization: Bearer <entraJwt>)
/// 2) All other /api/* -> MUST be valid session token (X-Session-Token OR Authorization: Bearer <sessionToken>)
/// 3) Dev bypass -> optional (Development or Auth:AllowDevBypass=true)
///
/// Populates ClientContext for downstream services.
/// Emits Warning logs so Azure Log Stream shows request-level auth flow.
/// Adds debug headers (X-Correlation-Id, X-Auth-Path, X-Auth-Fail).
/// </summary>
public sealed class ClientAuthMiddleware
{
private readonly RequestDelegate _next;
private readonly ILogger<ClientAuthMiddleware> _logger;
private readonly IConfiguration _config;
// Exact paths that do not require authentication
private static readonly HashSet<string> _anonymousExact = new(StringComparer.OrdinalIgnoreCase)
{
"/",
"/health"
};
// Prefix paths that do not require authentication
private static readonly string[] _anonymousPrefixes =
{
"/swagger",
"/api/test"
};
// Cache OpenID config manager (avoid fetching metadata every request)
private static ConfigurationManager<OpenIdConnectConfiguration>? _oidcConfigManager;
private static readonly object _oidcLock = new();
public ClientAuthMiddleware(RequestDelegate next, ILogger<ClientAuthMiddleware> logger, IConfiguration config)
{
_next = next;
_logger = logger;
_config = config;
}
public async Task InvokeAsync(HttpContext context, ClientContext clientContext, SqlService sql)
{
var pathRaw = context.Request.Path.Value ?? "";
var path = pathRaw.ToLowerInvariant();
var corrId = EnsureCorrelationId(context);
// Always visible in ACA log stream
_logger.LogWarning("[Auth] HIT {Method} {Path} | Corr={Corr}", context.Request.Method, pathRaw, corrId);
// Anonymous paths
if (IsAnonymousPath(path))
{
SetAuthDebugHeaders(context, corrId, authPath: "anonymous", authFail: null);
await _next(context);
return;
}
// ---------------------------------------------------------------------
// 1) SESSION EXCHANGE: MUST be Entra JWT
// ---------------------------------------------------------------------
if (path.StartsWith("/api/auth/session", StringComparison.OrdinalIgnoreCase))
{
if (await TryJwtAuthAsync(context, clientContext, corrId))
{
SetAuthDebugHeaders(context, corrId, authPath: "jwt(session-exchange)", authFail: null);
_logger.LogWarning("[Auth] Session exchange authorized via JWT | Email={Email} | Corr={Corr}",
clientContext.Email, corrId);
await _next(context);
return;
}
SetAuthDebugHeaders(context, corrId, authPath: "jwt(session-exchange)", authFail: "jwt-required");
_logger.LogWarning("[Auth] Session exchange denied: valid Entra JWT required | Corr={Corr}", corrId);
context.Response.StatusCode = 401;
await context.Response.WriteAsJsonAsync(new
{
ok = false,
error = "Valid Entra authentication required",
correlationId = corrId
});
return;
}
// ---------------------------------------------------------------------
// 2) ALL OTHER /api/auth/*: MUST be session (or dev bypass)
// (signoff, refresh, me, switch-client, etc.)
// ---------------------------------------------------------------------
if (path.StartsWith("/api/auth", StringComparison.OrdinalIgnoreCase))
{
if (TryDevBypass(context, clientContext, corrId))
{
SetAuthDebugHeaders(context, corrId, authPath: "dev-bypass(auth)", authFail: null);
await _next(context);
return;
}
if (await TrySessionAuthAsync(context, clientContext, sql, corrId))
{
SetAuthDebugHeaders(context, corrId, authPath: "session(auth)", authFail: null);
await _next(context);
return;
}
SetAuthDebugHeaders(context, corrId, authPath: "session(auth)", authFail: "session-required");
_logger.LogWarning("[Auth] /api/auth denied: valid session required | Corr={Corr}", corrId);
context.Response.StatusCode = 401;
await context.Response.WriteAsJsonAsync(new
{
ok = false,
error = "Valid session required",
correlationId = corrId
});
return;
}
// ---------------------------------------------------------------------
// 3) ALL OTHER REQUESTS (typically /api/*): MUST be session (or dev bypass)
// NO JWT FALLBACK. Keeps Bearer=<sessionToken> unambiguous.
// ---------------------------------------------------------------------
if (TryDevBypass(context, clientContext, corrId))
{
SetAuthDebugHeaders(context, corrId, authPath: "dev-bypass", authFail: null);
await _next(context);
return;
}
if (await TrySessionAuthAsync(context, clientContext, sql, corrId))
{
SetAuthDebugHeaders(context, corrId, authPath: "session", authFail: null);
await _next(context);
return;
}
SetAuthDebugHeaders(context, corrId, authPath: "session", authFail: "session-required");
_logger.LogWarning("[Auth] UNAUTHORIZED: valid session required | {Path} | Corr={Corr}", pathRaw, corrId);
context.Response.StatusCode = 401;
await context.Response.WriteAsJsonAsync(new
{
ok = false,
error = "Valid session required",
correlationId = corrId
});
}
private static bool IsAnonymousPath(string pathLower)
{
if (_anonymousExact.Contains(pathLower))
return true;
return _anonymousPrefixes.Any(p => pathLower.StartsWith(p, StringComparison.OrdinalIgnoreCase));
}
private static string EnsureCorrelationId(HttpContext context)
{
const string header = "X-Correlation-Id";
if (!context.Request.Headers.TryGetValue(header, out var existing) ||
string.IsNullOrWhiteSpace(existing.FirstOrDefault()))
{
var id = Guid.NewGuid().ToString("N");
context.Request.Headers[header] = id;
return id;
}
return existing.First()!;
}
private static void SetAuthDebugHeaders(HttpContext context, string corrId, string authPath, string? authFail)
{
context.Response.Headers["X-Correlation-Id"] = corrId;
context.Response.Headers["X-Auth-Path"] = authPath;
if (!string.IsNullOrWhiteSpace(authFail))
context.Response.Headers["X-Auth-Fail"] = authFail;
}
/// <summary>
/// Session token authentication: Validate against our session database.
/// Accepts X-Session-Token header OR Authorization: Bearer <sessionToken>.
/// </summary>
private async Task<bool> TrySessionAuthAsync(HttpContext context, ClientContext clientContext, SqlService sql, string corrId)
{
string? token = null;
if (context.Request.Headers.TryGetValue("X-Session-Token", out var sessionHeader))
token = sessionHeader.FirstOrDefault();
if (string.IsNullOrWhiteSpace(token) &&
context.Request.Headers.TryGetValue("Authorization", out var authHeader))
{
var headerValue = authHeader.FirstOrDefault();
if (!string.IsNullOrWhiteSpace(headerValue) &&
headerValue.StartsWith("Bearer ", StringComparison.OrdinalIgnoreCase))
{
token = headerValue["Bearer ".Length..].Trim();
}
}
if (string.IsNullOrWhiteSpace(token))
{
_logger.LogWarning("[Auth] Session auth skipped (no token) | Corr={Corr}", corrId);
return false;
}
try
{
_logger.LogWarning("[Auth] Session validation starting | Corr={Corr}", corrId);
var rqst = JsonSerializer.Serialize(new { sessionToken = token });
var resp = await sql.ExecProcAsync("dbo.spClientSession", "validate", rqst, ct: context.RequestAborted);
if (string.IsNullOrWhiteSpace(resp))
{
_logger.LogWarning("[Auth] Session validation failed: empty response | Corr={Corr}", corrId);
return false;
}
using var doc = JsonDocument.Parse(resp);
var root = doc.RootElement;
if (root.TryGetProperty("ok", out var okProp) && okProp.ValueKind == JsonValueKind.True)
{
var data = root.TryGetProperty("data", out var dataProp) ? dataProp : root;
clientContext.SessionId = data.TryGetProperty("sessionId", out var sid) ? sid.GetString() : null;
clientContext.ClientId = data.TryGetProperty("clientId", out var cid) ? cid.GetString() : null;
clientContext.ClientName = data.TryGetProperty("clientName", out var cn) ? cn.GetString() : null;
clientContext.ClientCategory = data.TryGetProperty("clientCategory", out var ccat) ? ccat.GetString() : null;
clientContext.UserId = data.TryGetProperty("userId", out var uid) ? uid.GetString() : null;
clientContext.Email = data.TryGetProperty("userEmail", out var ue) ? ue.GetString() : null;
clientContext.Role = data.TryGetProperty("role", out var role) ? role.GetString() : null;
clientContext.IsDevBypass = false;
_logger.LogWarning("[Auth] Session validated OK | ClientId={ClientId} Email={Email} | Corr={Corr}",
clientContext.ClientId, clientContext.Email, corrId);
return clientContext.IsAuthenticated;
}
_logger.LogWarning("[Auth] Session validation failed: ok=false | Corr={Corr}", corrId);
return false;
}
catch (Exception ex)
{
_logger.LogError(ex, "[Auth] Session validation error | Corr={Corr}", corrId);
return false;
}
}
/// <summary>
/// Development bypass: Accept X-Dev-ClientId header.
/// Only works when ASPNETCORE_ENVIRONMENT=Development or Auth:AllowDevBypass=true.
/// </summary>
private bool TryDevBypass(HttpContext context, ClientContext clientContext, string corrId)
{
var env = _config["ASPNETCORE_ENVIRONMENT"] ?? Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");
var allowBypass = _config.GetValue<bool>("Auth:AllowDevBypass");
if (!string.Equals(env, "Development", StringComparison.OrdinalIgnoreCase) && !allowBypass)
return false;
if (!context.Request.Headers.TryGetValue("X-Dev-ClientId", out var devClientId))
return false;
var clientId = devClientId.FirstOrDefault();
if (string.IsNullOrWhiteSpace(clientId))
return false;
clientContext.ClientId = clientId;
clientContext.IsDevBypass = true;
if (context.Request.Headers.TryGetValue("X-Dev-TenantId", out var devTenantId))
clientContext.TenantId = devTenantId.FirstOrDefault();
if (context.Request.Headers.TryGetValue("X-Dev-ClientName", out var devName))
clientContext.ClientName = devName.FirstOrDefault();
_logger.LogWarning("[Auth] Dev bypass OK | ClientId={ClientId} | Corr={Corr}", clientId, corrId);
return true;
}
/// <summary>
/// JWT authentication: Validate Entra ID Bearer token.
/// Used ONLY for /api/auth/session.
/// </summary>
private async Task<bool> TryJwtAuthAsync(HttpContext context, ClientContext clientContext, string corrId)
{
if (!context.Request.Headers.TryGetValue("Authorization", out var authHeader))
{
_logger.LogWarning("[Auth] JWT skipped (no Authorization) | Corr={Corr}", corrId);
return false;
}
var headerValue = authHeader.FirstOrDefault();
if (string.IsNullOrWhiteSpace(headerValue) ||
!headerValue.StartsWith("Bearer ", StringComparison.OrdinalIgnoreCase))
{
_logger.LogWarning("[Auth] JWT skipped (Authorization not Bearer) | Corr={Corr}", corrId);
return false;
}
var token = headerValue["Bearer ".Length..].Trim();
if (string.IsNullOrWhiteSpace(token))
{
_logger.LogWarning("[Auth] JWT skipped (empty bearer token) | Corr={Corr}", corrId);
return false;
}
var tenantId = _config["Auth:EntraId:TenantId"] ?? _config["ENTRA_TENANT_ID"];
var clientId = _config["Auth:EntraId:ClientId"] ?? _config["ENTRA_CLIENT_ID"];
var instance = _config["Auth:EntraId:Instance"] ?? "https://login.microsoftonline.com/";
var audienceOverride = _config["Auth:EntraId:Audience"]; // optional (e.g. api://xxx or App ID URI)
if (string.IsNullOrWhiteSpace(tenantId) || string.IsNullOrWhiteSpace(clientId))
{
_logger.LogWarning("[Auth] JWT disabled (missing TenantId/ClientId) | Corr={Corr}", corrId);
return false;
}
try
{
// Diagnostics (safe enough for logs; do NOT log full token)
var handler = new JwtSecurityTokenHandler();
if (handler.CanReadToken(token))
{
var jwt = handler.ReadJwtToken(token);
_logger.LogWarning("[Auth] JWT presented | iss={Iss} aud={Aud} sub={Sub} | Corr={Corr}",
jwt.Issuer, jwt.Audiences.FirstOrDefault(), jwt.Subject, corrId);
}
var authority = $"{instance.TrimEnd('/')}/{tenantId}/v2.0";
var metadataAddress = $"{authority}/.well-known/openid-configuration";
var mgr = GetOrCreateConfigManager(metadataAddress);
var openIdConfig = await mgr.GetConfigurationAsync(context.RequestAborted);
var validAudiences = new List<string> { clientId, $"api://{clientId}" };
if (!string.IsNullOrWhiteSpace(audienceOverride))
validAudiences.Add(audienceOverride);
// fix applied
var validationParams = new TokenValidationParameters
{
ValidateIssuer = true,
ValidIssuers = new[]
{
$"https://login.microsoftonline.com/{tenantId}/v2.0",
$"https://sts.windows.net/{tenantId}/"
},
ValidateAudience = true,
ValidAudiences = validAudiences,
ValidateLifetime = true,
IssuerSigningKeys = openIdConfig.SigningKeys,
ClockSkew = TimeSpan.FromMinutes(5)
};
var principal = handler.ValidateToken(token, validationParams, out _);
clientContext.ClientId =
principal.FindFirstValue("oid") ??
principal.FindFirstValue(ClaimTypes.NameIdentifier) ??
principal.FindFirstValue("sub");
clientContext.Email =
principal.FindFirstValue("preferred_username") ??
principal.FindFirstValue(ClaimTypes.Email) ??
principal.FindFirstValue("upn");
clientContext.ClientName =
principal.FindFirstValue("name") ??
principal.FindFirstValue(ClaimTypes.Name);
clientContext.IsDevBypass = false;
_logger.LogWarning("[Auth] JWT validated OK | oid={Oid} email={Email} | Corr={Corr}",
clientContext.ClientId, clientContext.Email, corrId);
return clientContext.IsAuthenticated;
}
catch (SecurityTokenException ex)
{
_logger.LogWarning("[Auth] JWT validation FAILED: {Msg} | Corr={Corr}", ex.Message, corrId);
return false;
}
catch (Exception ex)
{
_logger.LogError(ex, "[Auth] JWT validation ERROR | Corr={Corr}", corrId);
return false;
}
}
private static ConfigurationManager<OpenIdConnectConfiguration> GetOrCreateConfigManager(string metadataAddress)
{
lock (_oidcLock)
{
_oidcConfigManager ??= new ConfigurationManager<OpenIdConnectConfiguration>(
metadataAddress,
new OpenIdConnectConfigurationRetriever());
return _oidcConfigManager;
}
}
}