src/auth/negotiate/UserRequest.cc

   1 /*
   2  * Copyright (C) 1996-2020 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/negotiate/Config.h"
  13 #include "auth/negotiate/User.h"
  14 #include "auth/negotiate/UserRequest.h"
  15 #include "auth/State.h"
  16 #include "auth/User.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 "HttpHeaderTools.h"
  25 #include "HttpReply.h"
  26 #include "HttpRequest.h"
  27 #include "MemBuf.h"
  28 #include "SquidTime.h"
  29
  30 Auth::Negotiate::UserRequest::UserRequest() :
  31     server_blob(nullptr),
  32     client_blob(nullptr),
  33     waiting(0),
  34     request(nullptr)
  35 {}
  36
  37 Auth::Negotiate::UserRequest::~UserRequest()
  38 {
  39     assert(LockCount()==0);
  40     safe_free(server_blob);
  41     safe_free(client_blob);
  42
  43     releaseAuthServer();
  44
  45     if (request) {
  46         HTTPMSGUNLOCK(request);
  47         request = NULL;
  48     }
  49 }
  50
  51 const char *
  52 Auth::Negotiate::UserRequest::connLastHeader()
  53 {
  54     return NULL;
  55 }
  56
  57 int
  58 Auth::Negotiate::UserRequest::authenticated() const
  59 {
  60     if (user() != NULL && user()->credentials() == Auth::Ok) {
  61         debugs(29, 9, HERE << "user authenticated.");
  62         return 1;
  63     }
  64
  65     debugs(29, 9, HERE << "user not fully authenticated.");
  66     return 0;
  67 }
  68
  69 const char *
  70 Auth::Negotiate::UserRequest::credentialsStr()
  71 {
  72     static char buf[MAX_AUTHTOKEN_LEN];
  73     int printResult = 0;
  74     if (user()->credentials() == Auth::Pending) {
  75         printResult = snprintf(buf, sizeof(buf), "YR %s\n", client_blob); //CHECKME: can ever client_blob be 0 here?
  76     } else {
  77         printResult = snprintf(buf, sizeof(buf), "KK %s\n", client_blob);
  78     }
  79
  80     // truncation is OK because we are used only for logging
  81     if (printResult < 0) {
  82         debugs(29, 2, "Can not build negotiate authentication credentials.");
  83         buf[0] = '\0';
  84     } else if (printResult >= (int)sizeof(buf))
  85         debugs(29, 2, "Negotiate authentication credentials truncated.");
  86
  87     return buf;
  88 }
  89
  90 Auth::Direction
  91 Auth::Negotiate::UserRequest::module_direction()
  92 {
  93     /* null auth_user is checked for by Auth::UserRequest::direction() */
  94
  95     if (waiting || client_blob)
  96         return Auth::CRED_LOOKUP; /* need helper response to continue */
  97
  98     if (user()->auth_type != Auth::AUTH_NEGOTIATE)
  99         return Auth::CRED_ERROR;
 100
 101     switch (user()->credentials()) {
 102
 103     case Auth::Handshake:
 104         assert(server_blob);
 105         return Auth::CRED_CHALLENGE;
 106
 107     case Auth::Ok:
 108         return Auth::CRED_VALID;
 109
 110     case Auth::Failed:
 111         return Auth::CRED_ERROR; // XXX: really? not VALID or CHALLENGE?
 112
 113     default:
 114         debugs(29, DBG_IMPORTANT, "WARNING: Negotiate Authentication in unexpected state: " << user()->credentials());
 115         return Auth::CRED_ERROR;
 116     }
 117 }
 118
 119 void
 120 Auth::Negotiate::UserRequest::startHelperLookup(HttpRequest *, AccessLogEntry::Pointer &al, AUTHCB * handler, void *data)
 121 {
 122     static char buf[MAX_AUTHTOKEN_LEN];
 123
 124     assert(data);
 125     assert(handler);
 126
 127     assert(user() != NULL);
 128     assert(user()->auth_type == Auth::AUTH_NEGOTIATE);
 129
 130     if (static_cast<Auth::Negotiate::Config*>(Auth::SchemeConfig::Find("negotiate"))->authenticateProgram == NULL) {
 131         debugs(29, DBG_CRITICAL, "ERROR: No Negotiate authentication program configured.");
 132         handler(data);
 133         return;
 134     }
 135
 136     debugs(29, 8, HERE << "credentials state is '" << user()->credentials() << "'");
 137
 138     const char *keyExtras = helperRequestKeyExtras(request, al);
 139     int printResult = 0;
 140     if (user()->credentials() == Auth::Pending) {
 141         if (keyExtras)
 142             printResult = snprintf(buf, sizeof(buf), "YR %s %s\n", client_blob, keyExtras);
 143         else
 144             printResult = snprintf(buf, sizeof(buf), "YR %s\n", client_blob); //CHECKME: can ever client_blob be 0 here?
 145     } else {
 146         if (keyExtras)
 147             printResult = snprintf(buf, sizeof(buf), "KK %s %s\n", client_blob, keyExtras);
 148         else
 149             printResult = snprintf(buf, sizeof(buf), "KK %s\n", client_blob);
 150     }
 151
 152     if (printResult < 0 || printResult >= (int)sizeof(buf)) {
 153         if (printResult < 0)
 154             debugs(29, DBG_CRITICAL, "ERROR: Can not build negotiate authentication helper request");
 155         else
 156             debugs(29, DBG_CRITICAL, "ERROR: Negotiate authentication helper request too big for the " << sizeof(buf) << "-byte buffer");
 157         handler(data);
 158         return;
 159     }
 160
 161     waiting = 1;
 162
 163     safe_free(client_blob);
 164
 165     helperStatefulSubmit(negotiateauthenticators, buf, Auth::Negotiate::UserRequest::HandleReply,
 166                          new Auth::StateData(this, handler, data), reservationId);
 167 }
 168
 169 /**
 170  * Atomic action: properly release the Negotiate auth helpers which may have been reserved
 171  * for this request connections use.
 172  */
 173 void
 174 Auth::Negotiate::UserRequest::releaseAuthServer()
 175 {
 176     if (reservationId) {
 177         debugs(29, 6, reservationId);
 178         negotiateauthenticators->cancelReservation(reservationId);
 179         reservationId.clear();
 180     } else
 181         debugs(29, 6, HERE << "No Negotiate auth server to release.");
 182 }
 183
 184 void
 185 Auth::Negotiate::UserRequest::authenticate(HttpRequest * aRequest, ConnStateData * conn, Http::HdrType type)
 186 {
 187     /* Check that we are in the client side, where we can generate
 188      * auth challenges */
 189
 190     if (conn == NULL || !cbdataReferenceValid(conn)) {
 191         user()->credentials(Auth::Failed);
 192         debugs(29, DBG_IMPORTANT, "WARNING: Negotiate Authentication attempt to perform authentication without a connection!");
 193         return;
 194     }
 195
 196     if (waiting) {
 197         debugs(29, DBG_IMPORTANT, "WARNING: Negotiate Authentication waiting for helper reply!");
 198         return;
 199     }
 200
 201     if (server_blob) {
 202         debugs(29, 2, HERE << "need to challenge client '" << server_blob << "'!");
 203         return;
 204     }
 205
 206     /* get header */
 207     const char *proxy_auth = aRequest->header.getStr(type);
 208
 209     /* locate second word */
 210     const char *blob = proxy_auth;
 211
 212     if (blob) {
 213         while (xisspace(*blob) && *blob)
 214             ++blob;
 215
 216         while (!xisspace(*blob) && *blob)
 217             ++blob;
 218
 219         while (xisspace(*blob) && *blob)
 220             ++blob;
 221     }
 222
 223     switch (user()->credentials()) {
 224
 225     case Auth::Unchecked:
 226         /* we've received a negotiate request. pass to a helper */
 227         debugs(29, 9, HERE << "auth state negotiate none. Received blob: '" << proxy_auth << "'");
 228         user()->credentials(Auth::Pending);
 229         safe_free(client_blob);
 230         client_blob=xstrdup(blob);
 231         assert(conn->getAuth() == NULL);
 232         conn->setAuth(this, "new Negotiate handshake request");
 233         request = aRequest;
 234         HTTPMSGLOCK(request);
 235         break;
 236
 237     case Auth::Pending:
 238         debugs(29, DBG_IMPORTANT, HERE << "need to ask helper");
 239         break;
 240
 241     case Auth::Handshake:
 242         /* we should have received a blob from the client. Hand it off to
 243          * some helper */
 244         safe_free(client_blob);
 245         client_blob = xstrdup(blob);
 246         if (request)
 247             HTTPMSGUNLOCK(request);
 248         request = aRequest;
 249         HTTPMSGLOCK(request);
 250         break;
 251
 252     case Auth::Ok:
 253         fatal("Auth::Negotiate::UserRequest::authenticate: unexpected auth state DONE! Report a bug to the squid developers.\n");
 254         break;
 255
 256     case Auth::Failed:
 257         /* we've failed somewhere in authentication */
 258         debugs(29, 9, HERE << "auth state negotiate failed. " << proxy_auth);
 259         break;
 260     }
 261 }
 262
 263 void
 264 Auth::Negotiate::UserRequest::HandleReply(void *data, const Helper::Reply &reply)
 265 {
 266     Auth::StateData *r = static_cast<Auth::StateData *>(data);
 267
 268     debugs(29, 8, reply.reservationId << " got reply=" << reply);
 269
 270     if (!cbdataReferenceValid(r->data)) {
 271         debugs(29, DBG_IMPORTANT, "ERROR: Negotiate Authentication invalid callback data (" << reply.reservationId << ")");
 272         delete r;
 273         return;
 274     }
 275
 276     Auth::UserRequest::Pointer auth_user_request = r->auth_user_request;
 277     assert(auth_user_request != NULL);
 278
 279     // add new helper kv-pair notes to the credentials object
 280     // so that any transaction using those credentials can access them
 281     static const NotePairs::Names appendables = { SBuf("group"), SBuf("tag") };
 282     auth_user_request->user()->notes.replaceOrAddOrAppend(&reply.notes, appendables);
 283     // remove any private credentials detail which got added.
 284     auth_user_request->user()->notes.remove("token");
 285
 286     Auth::Negotiate::UserRequest *lm_request = dynamic_cast<Auth::Negotiate::UserRequest *>(auth_user_request.getRaw());
 287     assert(lm_request != NULL);
 288     assert(lm_request->waiting);
 289
 290     lm_request->waiting = 0;
 291     safe_free(lm_request->client_blob);
 292
 293     assert(auth_user_request->user() != NULL);
 294     assert(auth_user_request->user()->auth_type == Auth::AUTH_NEGOTIATE);
 295
 296     if (!lm_request->reservationId)
 297         lm_request->reservationId = reply.reservationId;
 298     else
 299         assert(reply.reservationId == lm_request->reservationId);
 300
 301     switch (reply.result) {
 302     case Helper::TT:
 303         /* we have been given a blob to send to the client */
 304         safe_free(lm_request->server_blob);
 305         lm_request->request->flags.mustKeepalive = true;
 306         if (lm_request->request->flags.proxyKeepalive) {
 307             const char *tokenNote = reply.notes.findFirst("token");
 308             lm_request->server_blob = xstrdup(tokenNote);
 309             auth_user_request->user()->credentials(Auth::Handshake);
 310             auth_user_request->setDenyMessage("Authentication in progress");
 311             debugs(29, 4, HERE << "Need to challenge the client with a server token: '" << tokenNote << "'");
 312         } else {
 313             auth_user_request->user()->credentials(Auth::Failed);
 314             auth_user_request->setDenyMessage("Negotiate authentication requires a persistent connection");
 315         }
 316         break;
 317
 318     case Helper::Okay: {
 319         const char *userNote = reply.notes.findFirst("user");
 320         const char *tokenNote = reply.notes.findFirst("token");
 321         if (userNote == NULL || tokenNote == NULL) {
 322             // XXX: handle a success with no username better
 323             /* protocol error */
 324             fatalf("authenticateNegotiateHandleReply: *** Unsupported helper response ***, '%s'\n", reply.other().content());
 325             break;
 326         }
 327
 328         /* we're finished, release the helper */
 329         auth_user_request->user()->username(userNote);
 330         auth_user_request->setDenyMessage("Login successful");
 331         safe_free(lm_request->server_blob);
 332         lm_request->server_blob = xstrdup(tokenNote);
 333         lm_request->releaseAuthServer();
 334
 335         /* connection is authenticated */
 336         debugs(29, 4, HERE << "authenticated user " << auth_user_request->user()->username());
 337         auto local_auth_user = lm_request->user();
 338         auto cached_user = Auth::Negotiate::User::Cache()->lookup(auth_user_request->user()->userKey());
 339         if (!cached_user) {
 340             local_auth_user->addToNameCache();
 341         } else {
 342             /* we can't seamlessly recheck the username due to the
 343              * challenge-response nature of the protocol.
 344              * Just free the temporary auth_user after merging as
 345              * much of it new state into the existing one as possible */
 346             cached_user->absorb(local_auth_user);
 347             /* from here on we are working with the original cached credentials. */
 348             local_auth_user = cached_user;
 349             auth_user_request->user(local_auth_user);
 350         }
 351         /* set these to now because this is either a new login from an
 352          * existing user or a new user */
 353         local_auth_user->expiretime = current_time.tv_sec;
 354         auth_user_request->user()->credentials(Auth::Ok);
 355         debugs(29, 4, HERE << "Successfully validated user via Negotiate. Username '" << auth_user_request->user()->username() << "'");
 356     }
 357     break;
 358
 359     case Helper::Error:
 360         /* authentication failure (wrong password, etc.) */
 361         auth_user_request->denyMessageFromHelper("Negotiate", reply);
 362         auth_user_request->user()->credentials(Auth::Failed);
 363         safe_free(lm_request->server_blob);
 364         if (const char *tokenNote = reply.notes.findFirst("token"))
 365             lm_request->server_blob = xstrdup(tokenNote);
 366         lm_request->releaseAuthServer();
 367         debugs(29, 4, "Failed validating user via Negotiate. Result: " << reply);
 368         break;
 369
 370     case Helper::Unknown:
 371         debugs(29, DBG_IMPORTANT, "ERROR: Negotiate Authentication Helper crashed (" << reply.reservationId << ")");
 372     /* continue to the next case */
 373
 374     case Helper::TimedOut:
 375     case Helper::BrokenHelper:
 376         /* TODO kick off a refresh process. This can occur after a YR or after
 377          * a KK. If after a YR release the helper and resubmit the request via
 378          * Authenticate Negotiate start.
 379          * If after a KK deny the user's request w/ 407 and mark the helper as
 380          * Needing YR. */
 381         if (reply.result == Helper::Unknown)
 382             auth_user_request->setDenyMessage("Internal Error");
 383         else
 384             auth_user_request->denyMessageFromHelper("Negotiate", reply);
 385         auth_user_request->user()->credentials(Auth::Failed);
 386         safe_free(lm_request->server_blob);
 387         lm_request->releaseAuthServer();
 388         debugs(29, DBG_IMPORTANT, "ERROR: Negotiate Authentication validating user. Result: " << reply);
 389         break;
 390     }
 391
 392     if (lm_request->request) {
 393         HTTPMSGUNLOCK(lm_request->request);
 394         lm_request->request = NULL;
 395     }
 396     r->handler(r->data);
 397     delete r;
 398 }
 399