src/auth/ntlm/UserRequest.cc

   1 /*
   2  * Copyright (C) 1996-2021 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #include "squid.h"
  10 #include "AccessLogEntry.h"
  11 #include "auth/CredentialsCache.h"
  12 #include "auth/ntlm/Config.h"
  13 #include "auth/ntlm/User.h"
  14 #include "auth/ntlm/UserRequest.h"
  15 #include "auth/State.h"
  16 #include "cbdata.h"
  17 #include "client_side.h"
  18 #include "fatal.h"
  19 #include "format/Format.h"
  20 #include "globals.h"
  21 #include "helper.h"
  22 #include "helper/Reply.h"
  23 #include "http/Stream.h"
  24 #include "HttpRequest.h"
  25 #include "MemBuf.h"
  26 #include "SquidTime.h"
  27
  28 Auth::Ntlm::UserRequest::UserRequest() :
  29     server_blob(nullptr),
  30     client_blob(nullptr),
  31     waiting(0),
  32     request(nullptr)
  33 {}
  34
  35 Auth::Ntlm::UserRequest::~UserRequest()
  36 {
  37     assert(LockCount()==0);
  38     safe_free(server_blob);
  39     safe_free(client_blob);
  40
  41     releaseAuthServer();
  42
  43     if (request) {
  44         HTTPMSGUNLOCK(request);
  45         request = NULL;
  46     }
  47 }
  48
  49 const char *
  50 Auth::Ntlm::UserRequest::connLastHeader()
  51 {
  52     return NULL;
  53 }
  54
  55 int
  56 Auth::Ntlm::UserRequest::authenticated() const
  57 {
  58     if (user() != NULL && user()->credentials() == Auth::Ok) {
  59         debugs(29, 9, HERE << "user authenticated.");
  60         return 1;
  61     }
  62
  63     debugs(29, 9, HERE << "user not fully authenticated.");
  64     return 0;
  65 }
  66
  67 const char *
  68 Auth::Ntlm::UserRequest::credentialsStr()
  69 {
  70     static char buf[MAX_AUTHTOKEN_LEN];
  71     int printResult;
  72     if (user()->credentials() == Auth::Pending) {
  73         printResult = snprintf(buf, sizeof(buf), "YR %s\n", client_blob);
  74     } else {
  75         printResult = snprintf(buf, sizeof(buf), "KK %s\n", client_blob);
  76     }
  77
  78     // truncation is OK because we are used only for logging
  79     if (printResult < 0) {
  80         debugs(29, 2, "Can not build ntlm authentication credentials.");
  81         buf[0] = '\0';
  82     } else if (printResult >= (int)sizeof(buf))
  83         debugs(29, 2, "Ntlm authentication credentials truncated.");
  84
  85     return buf;
  86 }
  87
  88 Auth::Direction
  89 Auth::Ntlm::UserRequest::module_direction()
  90 {
  91     /* null auth_user is checked for by Auth::UserRequest::direction() */
  92
  93     if (waiting || client_blob)
  94         return Auth::CRED_LOOKUP; /* need helper response to continue */
  95
  96     if (user()->auth_type != Auth::AUTH_NTLM)
  97         return Auth::CRED_ERROR;
  98
  99     switch (user()->credentials()) {
 100
 101     case Auth::Handshake:
 102         assert(server_blob);
 103         return Auth::CRED_CHALLENGE;
 104
 105     case Auth::Ok:
 106         return Auth::CRED_VALID;
 107
 108     case Auth::Failed:
 109         return Auth::CRED_ERROR; // XXX: really? not VALID or CHALLENGE?
 110
 111     default:
 112         debugs(29, DBG_IMPORTANT, "WARNING: NTLM Authentication in unexpected state: " << user()->credentials());
 113         return Auth::CRED_ERROR;
 114     }
 115 }
 116
 117 void
 118 Auth::Ntlm::UserRequest::startHelperLookup(HttpRequest *, AccessLogEntry::Pointer &al, AUTHCB * handler, void *data)
 119 {
 120     static char buf[MAX_AUTHTOKEN_LEN];
 121
 122     assert(data);
 123     assert(handler);
 124
 125     if (static_cast<Auth::Ntlm::Config*>(Auth::SchemeConfig::Find("ntlm"))->authenticateProgram == NULL) {
 126         debugs(29, DBG_CRITICAL, "ERROR: NTLM Start: no NTLM program configured.");
 127         handler(data);
 128         return;
 129     }
 130
 131     debugs(29, 8, HERE << "credentials state is '" << user()->credentials() << "'");
 132
 133     const char *keyExtras = helperRequestKeyExtras(request, al);
 134     int printResult = 0;
 135     if (user()->credentials() == Auth::Pending) {
 136         if (keyExtras)
 137             printResult = snprintf(buf, sizeof(buf), "YR %s %s\n", client_blob, keyExtras);
 138         else
 139             printResult = snprintf(buf, sizeof(buf), "YR %s\n", client_blob); //CHECKME: can ever client_blob be 0 here?
 140     } else {
 141         if (keyExtras)
 142             printResult = snprintf(buf, sizeof(buf), "KK %s %s\n", client_blob, keyExtras);
 143         else
 144             printResult = snprintf(buf, sizeof(buf), "KK %s\n", client_blob);
 145     }
 146     waiting = 1;
 147
 148     if (printResult < 0 || printResult >= (int)sizeof(buf)) {
 149         if (printResult < 0)
 150             debugs(29, DBG_CRITICAL, "ERROR: Can not build ntlm authentication helper request");
 151         else
 152             debugs(29, DBG_CRITICAL, "ERROR: Ntlm authentication helper request too big for the " << sizeof(buf) << "-byte buffer.");
 153         handler(data);
 154         return;
 155     }
 156
 157     safe_free(client_blob);
 158     helperStatefulSubmit(ntlmauthenticators, buf, Auth::Ntlm::UserRequest::HandleReply,
 159                          new Auth::StateData(this, handler, data), reservationId);
 160 }
 161
 162 /**
 163  * Atomic action: properly release the NTLM auth helpers which may have been reserved
 164  * for this request connections use.
 165  */
 166 void
 167 Auth::Ntlm::UserRequest::releaseAuthServer()
 168 {
 169     if (reservationId) {
 170         debugs(29, 6, reservationId);
 171         ntlmauthenticators->cancelReservation(reservationId);
 172         reservationId.clear();
 173     } else
 174         debugs(29, 6, HERE << "No NTLM auth server to release.");
 175 }
 176
 177 void
 178 Auth::Ntlm::UserRequest::authenticate(HttpRequest * aRequest, ConnStateData * conn, Http::HdrType type)
 179 {
 180     /* Check that we are in the client side, where we can generate
 181      * auth challenges */
 182
 183     if (conn == NULL || !cbdataReferenceValid(conn)) {
 184         user()->credentials(Auth::Failed);
 185         debugs(29, DBG_IMPORTANT, "WARNING: NTLM Authentication attempt to perform authentication without a connection!");
 186         return;
 187     }
 188
 189     if (waiting) {
 190         debugs(29, DBG_IMPORTANT, "WARNING: NTLM Authentication waiting for helper reply!");
 191         return;
 192     }
 193
 194     if (server_blob) {
 195         debugs(29, 2, HERE << "need to challenge client '" << server_blob << "'!");
 196         return;
 197     }
 198
 199     /* get header */
 200     const char *proxy_auth = aRequest->header.getStr(type);
 201
 202     /* locate second word */
 203     const char *blob = proxy_auth;
 204
 205     /* if proxy_auth is actually NULL, we'd better not manipulate it. */
 206     if (blob) {
 207         while (xisspace(*blob) && *blob)
 208             ++blob;
 209
 210         while (!xisspace(*blob) && *blob)
 211             ++blob;
 212
 213         while (xisspace(*blob) && *blob)
 214             ++blob;
 215     }
 216
 217     switch (user()->credentials()) {
 218
 219     case Auth::Unchecked:
 220         /* we've received a ntlm request. pass to a helper */
 221         debugs(29, 9, HERE << "auth state ntlm none. Received blob: '" << proxy_auth << "'");
 222         user()->credentials(Auth::Pending);
 223         safe_free(client_blob);
 224         client_blob=xstrdup(blob);
 225         assert(conn->getAuth() == NULL);
 226         conn->setAuth(this, "new NTLM handshake request");
 227         request = aRequest;
 228         HTTPMSGLOCK(request);
 229         break;
 230
 231     case Auth::Pending:
 232         debugs(29, DBG_IMPORTANT, HERE << "need to ask helper");
 233         break;
 234
 235     case Auth::Handshake:
 236         /* we should have received a blob from the client. Hand it off to
 237          * some helper */
 238         safe_free(client_blob);
 239         client_blob = xstrdup(blob);
 240         if (request)
 241             HTTPMSGUNLOCK(request);
 242         request = aRequest;
 243         HTTPMSGLOCK(request);
 244         break;
 245
 246     case Auth::Ok:
 247         fatal("Auth::Ntlm::UserRequest::authenticate: unexpected auth state DONE! Report a bug to the squid developers.\n");
 248         break;
 249
 250     case Auth::Failed:
 251         /* we've failed somewhere in authentication */
 252         debugs(29, 9, HERE << "auth state ntlm failed. " << proxy_auth);
 253         break;
 254     }
 255 }
 256
 257 void
 258 Auth::Ntlm::UserRequest::HandleReply(void *data, const Helper::Reply &reply)
 259 {
 260     Auth::StateData *r = static_cast<Auth::StateData *>(data);
 261
 262     debugs(29, 8, reply.reservationId << " got reply=" << reply);
 263
 264     if (!cbdataReferenceValid(r->data)) {
 265         debugs(29, DBG_IMPORTANT, "ERROR: NTLM Authentication invalid callback data(" << reply.reservationId <<")");
 266         delete r;
 267         return;
 268     }
 269
 270     Auth::UserRequest::Pointer auth_user_request = r->auth_user_request;
 271     assert(auth_user_request != NULL);
 272
 273     // add new helper kv-pair notes to the credentials object
 274     // so that any transaction using those credentials can access them
 275     static const NotePairs::Names appendables = { SBuf("group"), SBuf("tag") };
 276     auth_user_request->user()->notes.replaceOrAddOrAppend(&reply.notes, appendables);
 277     // remove any private credentials detail which got added.
 278     auth_user_request->user()->notes.remove("token");
 279
 280     Auth::Ntlm::UserRequest *lm_request = dynamic_cast<Auth::Ntlm::UserRequest *>(auth_user_request.getRaw());
 281     assert(lm_request != NULL);
 282     assert(lm_request->waiting);
 283
 284     lm_request->waiting = 0;
 285     safe_free(lm_request->client_blob);
 286
 287     assert(auth_user_request->user() != NULL);
 288     assert(auth_user_request->user()->auth_type == Auth::AUTH_NTLM);
 289
 290     if (!lm_request->reservationId)
 291         lm_request->reservationId = reply.reservationId;
 292     else
 293         assert(lm_request->reservationId == reply.reservationId);
 294
 295     switch (reply.result) {
 296     case Helper::TT:
 297         /* we have been given a blob to send to the client */
 298         safe_free(lm_request->server_blob);
 299         lm_request->request->flags.mustKeepalive = true;
 300         if (lm_request->request->flags.proxyKeepalive) {
 301             const char *serverBlob = reply.notes.findFirst("token");
 302             lm_request->server_blob = xstrdup(serverBlob);
 303             auth_user_request->user()->credentials(Auth::Handshake);
 304             auth_user_request->setDenyMessage("Authentication in progress");
 305             debugs(29, 4, HERE << "Need to challenge the client with a server token: '" << serverBlob << "'");
 306         } else {
 307             auth_user_request->user()->credentials(Auth::Failed);
 308             auth_user_request->setDenyMessage("NTLM authentication requires a persistent connection");
 309         }
 310         break;
 311
 312     case Helper::Okay: {
 313         /* we're finished, release the helper */
 314         const char *userLabel = reply.notes.findFirst("user");
 315         if (!userLabel) {
 316             auth_user_request->user()->credentials(Auth::Failed);
 317             safe_free(lm_request->server_blob);
 318             lm_request->releaseAuthServer();
 319             debugs(29, DBG_CRITICAL, "ERROR: NTLM Authentication helper returned no username. Result: " << reply);
 320             break;
 321         }
 322         auth_user_request->user()->username(userLabel);
 323         auth_user_request->setDenyMessage("Login successful");
 324         safe_free(lm_request->server_blob);
 325         lm_request->releaseAuthServer();
 326
 327         debugs(29, 4, HERE << "Successfully validated user via NTLM. Username '" << userLabel << "'");
 328         /* connection is authenticated */
 329         debugs(29, 4, HERE << "authenticated user " << auth_user_request->user()->username());
 330         /* see if this is an existing user */
 331         auto local_auth_user = lm_request->user();
 332         auto cached_user = Auth::Ntlm::User::Cache()->lookup(auth_user_request->user()->userKey());
 333         if (!cached_user) {
 334             local_auth_user->addToNameCache();
 335         } else {
 336             /* we can't seamlessly recheck the username due to the
 337              * challenge-response nature of the protocol.
 338              * Just free the temporary auth_user after merging as
 339              * much of it new state into the existing one as possible */
 340             cached_user->absorb(local_auth_user);
 341             /* from here on we are working with the original cached credentials. */
 342             local_auth_user = cached_user;
 343             auth_user_request->user(local_auth_user);
 344         }
 345         /* set these to now because this is either a new login from an
 346          * existing user or a new user */
 347         local_auth_user->expiretime = current_time.tv_sec;
 348         auth_user_request->user()->credentials(Auth::Ok);
 349         debugs(29, 4, HERE << "Successfully validated user via NTLM. Username '" << auth_user_request->user()->username() << "'");
 350     }
 351     break;
 352
 353     case Helper::Error:
 354         /* authentication failure (wrong password, etc.) */
 355         auth_user_request->denyMessageFromHelper("NTLM", reply);
 356         auth_user_request->user()->credentials(Auth::Failed);
 357         safe_free(lm_request->server_blob);
 358         lm_request->releaseAuthServer();
 359         debugs(29, 4, "Failed validating user via NTLM. Result: " << reply);
 360         break;
 361
 362     case Helper::Unknown:
 363         debugs(29, DBG_IMPORTANT, "ERROR: NTLM Authentication Helper crashed (" << reply.reservationId << ")");
 364     /* continue to the next case */
 365
 366     case Helper::TimedOut:
 367     case Helper::BrokenHelper:
 368         /* TODO kick off a refresh process. This can occur after a YR or after
 369          * a KK. If after a YR release the helper and resubmit the request via
 370          * Authenticate NTLM start.
 371          * If after a KK deny the user's request w/ 407 and mark the helper as
 372          * Needing YR. */
 373         if (reply.result == Helper::Unknown)
 374             auth_user_request->setDenyMessage("Internal Error");
 375         else
 376             auth_user_request->denyMessageFromHelper("NTLM", reply);
 377         auth_user_request->user()->credentials(Auth::Failed);
 378         safe_free(lm_request->server_blob);
 379         lm_request->releaseAuthServer();
 380         debugs(29, DBG_IMPORTANT, "ERROR: NTLM Authentication validating user. Result: " << reply);
 381         break;
 382     }
 383
 384     if (lm_request->request) {
 385         HTTPMSGUNLOCK(lm_request->request);
 386         lm_request->request = NULL;
 387     }
 388     r->handler(r->data);
 389     delete r;
 390 }
 391