granicus.if.org Git - postgresql/blob - src/backend/libpq/auth.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * auth.c
   4  *        Routines to handle network authentication
   5  *
   6  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        $PostgreSQL: pgsql/src/backend/libpq/auth.c,v 1.148 2007/02/08 04:52:18 momjian Exp $
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15
  16 #include "postgres.h"
  17
  18 #include <sys/param.h>
  19 #include <sys/socket.h>
  20 #if defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || defined(HAVE_STRUCT_SOCKCRED)
  21 #include <sys/uio.h>
  22 #include <sys/ucred.h>
  23 #endif
  24 #include <netinet/in.h>
  25 #include <arpa/inet.h>
  26
  27 #include "libpq/auth.h"
  28 #include "libpq/crypt.h"
  29 #include "libpq/ip.h"
  30 #include "libpq/libpq.h"
  31 #include "libpq/pqformat.h"
  32 #include "storage/ipc.h"
  33
  34
  35 static void sendAuthRequest(Port *port, AuthRequest areq);
  36 static void auth_failed(Port *port, int status);
  37 static char *recv_password_packet(Port *port);
  38 static int      recv_and_check_password_packet(Port *port);
  39
  40 char       *pg_krb_server_keyfile;
  41 char       *pg_krb_srvnam;
  42 bool            pg_krb_caseins_users;
  43 char       *pg_krb_server_hostname = NULL;
  44
  45 #ifdef USE_PAM
  46 #ifdef HAVE_PAM_PAM_APPL_H
  47 #include <pam/pam_appl.h>
  48 #endif
  49 #ifdef HAVE_SECURITY_PAM_APPL_H
  50 #include <security/pam_appl.h>
  51 #endif
  52
  53 #define PGSQL_PAM_SERVICE "postgresql"  /* Service name passed to PAM */
  54
  55 static int      CheckPAMAuth(Port *port, char *user, char *password);
  56 static int pam_passwd_conv_proc(int num_msg, const struct pam_message ** msg,
  57                                          struct pam_response ** resp, void *appdata_ptr);
  58
  59 static struct pam_conv pam_passw_conv = {
  60         &pam_passwd_conv_proc,
  61         NULL
  62 };
  63
  64 static char *pam_passwd = NULL; /* Workaround for Solaris 2.6 brokenness */
  65 static Port *pam_port_cludge;   /* Workaround for passing "Port *port" into
  66                                                                  * pam_passwd_conv_proc */
  67 #endif   /* USE_PAM */
  68
  69 #ifdef USE_LDAP
  70 #ifndef WIN32
  71 /* We use a deprecated function to keep the codepath the same as win32. */
  72 #define LDAP_DEPRECATED 1
  73 #include <ldap.h>
  74 #else
  75 #include <winldap.h>
  76
  77 /* Correct header from the Platform SDK */
  78 typedef
  79 ULONG(*__ldap_start_tls_sA) (
  80                                                          IN PLDAP ExternalHandle,
  81                                                          OUT PULONG ServerReturnValue,
  82                                                          OUT LDAPMessage ** result,
  83                                                          IN PLDAPControlA * ServerControls,
  84                                                          IN PLDAPControlA * ClientControls
  85 );
  86 #endif
  87
  88 static int      CheckLDAPAuth(Port *port);
  89 #endif
  90
  91
  92 #ifdef KRB5
  93 /*----------------------------------------------------------------
  94  * MIT Kerberos authentication system - protocol version 5
  95  *----------------------------------------------------------------
  96  */
  97
  98 #include <krb5.h>
  99 /* Some old versions of Kerberos do not include <com_err.h> in <krb5.h> */
 100 #if !defined(__COM_ERR_H) && !defined(__COM_ERR_H__)
 101 #include <com_err.h>
 102 #endif
 103
 104 /*
 105  * pg_an_to_ln -- return the local name corresponding to an authentication
 106  *                                name
 107  *
 108  * XXX Assumes that the first aname component is the user name.  This is NOT
 109  *         necessarily so, since an aname can actually be something out of your
 110  *         worst X.400 nightmare, like
 111  *                ORGANIZATION=U. C. Berkeley/NAME=Paul M. Aoki@CS.BERKELEY.EDU
 112  *         Note that the MIT an_to_ln code does the same thing if you don't
 113  *         provide an aname mapping database...it may be a better idea to use
 114  *         krb5_an_to_ln, except that it punts if multiple components are found,
 115  *         and we can't afford to punt.
 116  */
 117 static char *
 118 pg_an_to_ln(char *aname)
 119 {
 120         char       *p;
 121
 122         if ((p = strchr(aname, '/')) || (p = strchr(aname, '@')))
 123                 *p = '\0';
 124         return aname;
 125 }
 126
 127
 128 /*
 129  * Various krb5 state which is not connection specfic, and a flag to
 130  * indicate whether we have initialised it yet.
 131  */
 132 static int      pg_krb5_initialised;
 133 static krb5_context pg_krb5_context;
 134 static krb5_keytab pg_krb5_keytab;
 135 static krb5_principal pg_krb5_server;
 136
 137
 138 static int
 139 pg_krb5_init(void)
 140 {
 141         krb5_error_code retval;
 142         char       *khostname;
 143
 144         if (pg_krb5_initialised)
 145                 return STATUS_OK;
 146
 147         retval = krb5_init_context(&pg_krb5_context);
 148         if (retval)
 149         {
 150                 ereport(LOG,
 151                                 (errmsg("Kerberos initialization returned error %d",
 152                                                 retval)));
 153                 com_err("postgres", retval, "while initializing krb5");
 154                 return STATUS_ERROR;
 155         }
 156
 157         retval = krb5_kt_resolve(pg_krb5_context, pg_krb_server_keyfile, &pg_krb5_keytab);
 158         if (retval)
 159         {
 160                 ereport(LOG,
 161                                 (errmsg("Kerberos keytab resolving returned error %d",
 162                                                 retval)));
 163                 com_err("postgres", retval, "while resolving keytab file \"%s\"",
 164                                 pg_krb_server_keyfile);
 165                 krb5_free_context(pg_krb5_context);
 166                 return STATUS_ERROR;
 167         }
 168
 169         /*
 170          * If no hostname was specified, pg_krb_server_hostname is already NULL.
 171          * If it's set to blank, force it to NULL.
 172          */
 173         khostname = pg_krb_server_hostname;
 174         if (khostname && khostname[0] == '\0')
 175                 khostname = NULL;
 176
 177         retval = krb5_sname_to_principal(pg_krb5_context,
 178                                                                          khostname,
 179                                                                          pg_krb_srvnam,
 180                                                                          KRB5_NT_SRV_HST,
 181                                                                          &pg_krb5_server);
 182         if (retval)
 183         {
 184                 ereport(LOG,
 185                                 (errmsg("Kerberos sname_to_principal(\"%s\", \"%s\") returned error %d",
 186                  khostname ? khostname : "server hostname", pg_krb_srvnam, retval)));
 187                 com_err("postgres", retval,
 188                 "while getting server principal for server \"%s\" for service \"%s\"",
 189                                 khostname ? khostname : "server hostname", pg_krb_srvnam);
 190                 krb5_kt_close(pg_krb5_context, pg_krb5_keytab);
 191                 krb5_free_context(pg_krb5_context);
 192                 return STATUS_ERROR;
 193         }
 194
 195         pg_krb5_initialised = 1;
 196         return STATUS_OK;
 197 }
 198
 199
 200 /*
 201  * pg_krb5_recvauth -- server routine to receive authentication information
 202  *                                         from the client
 203  *
 204  * We still need to compare the username obtained from the client's setup
 205  * packet to the authenticated name.
 206  *
 207  * We have our own keytab file because postgres is unlikely to run as root,
 208  * and so cannot read the default keytab.
 209  */
 210 static int
 211 pg_krb5_recvauth(Port *port)
 212 {
 213         krb5_error_code retval;
 214         int                     ret;
 215         krb5_auth_context auth_context = NULL;
 216         krb5_ticket *ticket;
 217         char       *kusername;
 218
 219         if (get_role_line(port->user_name) == NULL)
 220                 return STATUS_ERROR;
 221
 222         ret = pg_krb5_init();
 223         if (ret != STATUS_OK)
 224                 return ret;
 225
 226         retval = krb5_recvauth(pg_krb5_context, &auth_context,
 227                                                    (krb5_pointer) & port->sock, pg_krb_srvnam,
 228                                                    pg_krb5_server, 0, pg_krb5_keytab, &ticket);
 229         if (retval)
 230         {
 231                 ereport(LOG,
 232                                 (errmsg("Kerberos recvauth returned error %d",
 233                                                 retval)));
 234                 com_err("postgres", retval, "from krb5_recvauth");
 235                 return STATUS_ERROR;
 236         }
 237
 238         /*
 239          * The "client" structure comes out of the ticket and is therefore
 240          * authenticated.  Use it to check the username obtained from the
 241          * postmaster startup packet.
 242          *
 243          * I have no idea why this is considered necessary.
 244          */
 245 #if defined(HAVE_KRB5_TICKET_ENC_PART2)
 246         retval = krb5_unparse_name(pg_krb5_context,
 247                                                            ticket->enc_part2->client, &kusername);
 248 #elif defined(HAVE_KRB5_TICKET_CLIENT)
 249         retval = krb5_unparse_name(pg_krb5_context,
 250                                                            ticket->client, &kusername);
 251 #else
 252 #error "bogus configuration"
 253 #endif
 254         if (retval)
 255         {
 256                 ereport(LOG,
 257                                 (errmsg("Kerberos unparse_name returned error %d",
 258                                                 retval)));
 259                 com_err("postgres", retval, "while unparsing client name");
 260                 krb5_free_ticket(pg_krb5_context, ticket);
 261                 krb5_auth_con_free(pg_krb5_context, auth_context);
 262                 return STATUS_ERROR;
 263         }
 264
 265         kusername = pg_an_to_ln(kusername);
 266         if (pg_krb_caseins_users)
 267                 ret = pg_strncasecmp(port->user_name, kusername, SM_DATABASE_USER);
 268         else
 269                 ret = strncmp(port->user_name, kusername, SM_DATABASE_USER);
 270         if (ret)
 271         {
 272                 ereport(LOG,
 273                                 (errmsg("unexpected Kerberos user name received from client (received \"%s\", expected \"%s\")",
 274                                                 port->user_name, kusername)));
 275                 ret = STATUS_ERROR;
 276         }
 277         else
 278                 ret = STATUS_OK;
 279
 280         krb5_free_ticket(pg_krb5_context, ticket);
 281         krb5_auth_con_free(pg_krb5_context, auth_context);
 282         free(kusername);
 283
 284         return ret;
 285 }
 286 #else
 287
 288 static int
 289 pg_krb5_recvauth(Port *port)
 290 {
 291         ereport(LOG,
 292                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 293                          errmsg("Kerberos 5 not implemented on this server")));
 294         return STATUS_ERROR;
 295 }
 296 #endif   /* KRB5 */
 297
 298
 299 /*
 300  * Tell the user the authentication failed, but not (much about) why.
 301  *
 302  * There is a tradeoff here between security concerns and making life
 303  * unnecessarily difficult for legitimate users.  We would not, for example,
 304  * want to report the password we were expecting to receive...
 305  * But it seems useful to report the username and authorization method
 306  * in use, and these are items that must be presumed known to an attacker
 307  * anyway.
 308  * Note that many sorts of failure report additional information in the
 309  * postmaster log, which we hope is only readable by good guys.
 310  */
 311 static void
 312 auth_failed(Port *port, int status)
 313 {
 314         const char *errstr;
 315
 316         /*
 317          * If we failed due to EOF from client, just quit; there's no point in
 318          * trying to send a message to the client, and not much point in logging
 319          * the failure in the postmaster log.  (Logging the failure might be
 320          * desirable, were it not for the fact that libpq closes the connection
 321          * unceremoniously if challenged for a password when it hasn't got one to
 322          * send.  We'll get a useless log entry for every psql connection under
 323          * password auth, even if it's perfectly successful, if we log STATUS_EOF
 324          * events.)
 325          */
 326         if (status == STATUS_EOF)
 327                 proc_exit(0);
 328
 329         switch (port->auth_method)
 330         {
 331                 case uaReject:
 332                         errstr = gettext_noop("authentication failed for user \"%s\": host rejected");
 333                         break;
 334                 case uaKrb5:
 335                         errstr = gettext_noop("Kerberos 5 authentication failed for user \"%s\"");
 336                         break;
 337                 case uaTrust:
 338                         errstr = gettext_noop("\"trust\" authentication failed for user \"%s\"");
 339                         break;
 340                 case uaIdent:
 341                         errstr = gettext_noop("Ident authentication failed for user \"%s\"");
 342                         break;
 343                 case uaMD5:
 344                 case uaCrypt:
 345                 case uaPassword:
 346                         errstr = gettext_noop("password authentication failed for user \"%s\"");
 347                         break;
 348 #ifdef USE_PAM
 349                 case uaPAM:
 350                         errstr = gettext_noop("PAM authentication failed for user \"%s\"");
 351                         break;
 352 #endif   /* USE_PAM */
 353 #ifdef USE_LDAP
 354                 case uaLDAP:
 355                         errstr = gettext_noop("LDAP authentication failed for user \"%s\"");
 356                         break;
 357 #endif   /* USE_LDAP */
 358                 default:
 359                         errstr = gettext_noop("authentication failed for user \"%s\": invalid authentication method");
 360                         break;
 361         }
 362
 363         ereport(FATAL,
 364                         (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
 365                          errmsg(errstr, port->user_name)));
 366         /* doesn't return */
 367 }
 368
 369
 370 /*
 371  * Client authentication starts here.  If there is an error, this
 372  * function does not return and the backend process is terminated.
 373  */
 374 void
 375 ClientAuthentication(Port *port)
 376 {
 377         int                     status = STATUS_ERROR;
 378
 379         /*
 380          * Get the authentication method to use for this frontend/database
 381          * combination.  Note: a failure return indicates a problem with the hba
 382          * config file, not with the request.  hba.c should have dropped an error
 383          * message into the postmaster logfile if it failed.
 384          */
 385         if (hba_getauthmethod(port) != STATUS_OK)
 386                 ereport(FATAL,
 387                                 (errcode(ERRCODE_CONFIG_FILE_ERROR),
 388                                  errmsg("missing or erroneous pg_hba.conf file"),
 389                                  errhint("See server log for details.")));
 390
 391         switch (port->auth_method)
 392         {
 393                 case uaReject:
 394
 395                         /*
 396                          * This could have come from an explicit "reject" entry in
 397                          * pg_hba.conf, but more likely it means there was no matching
 398                          * entry.  Take pity on the poor user and issue a helpful error
 399                          * message.  NOTE: this is not a security breach, because all the
 400                          * info reported here is known at the frontend and must be assumed
 401                          * known to bad guys. We're merely helping out the less clueful
 402                          * good guys.
 403                          */
 404                         {
 405                                 char            hostinfo[NI_MAXHOST];
 406
 407                                 pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
 408                                                                    hostinfo, sizeof(hostinfo),
 409                                                                    NULL, 0,
 410                                                                    NI_NUMERICHOST);
 411
 412 #ifdef USE_SSL
 413                                 ereport(FATAL,
 414                                                 (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
 415                                                  errmsg("no pg_hba.conf entry for host \"%s\", user \"%s\", database \"%s\", %s",
 416                                                           hostinfo, port->user_name, port->database_name,
 417                                                                 port->ssl ? _("SSL on") : _("SSL off"))));
 418 #else
 419                                 ereport(FATAL,
 420                                                 (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
 421                                                  errmsg("no pg_hba.conf entry for host \"%s\", user \"%s\", database \"%s\"",
 422                                                    hostinfo, port->user_name, port->database_name)));
 423 #endif
 424                                 break;
 425                         }
 426
 427                 case uaKrb5:
 428                         sendAuthRequest(port, AUTH_REQ_KRB5);
 429                         status = pg_krb5_recvauth(port);
 430                         break;
 431
 432                 case uaIdent:
 433
 434                         /*
 435                          * If we are doing ident on unix-domain sockets, use SCM_CREDS
 436                          * only if it is defined and SO_PEERCRED isn't.
 437                          */
 438 #if !defined(HAVE_GETPEEREID) && !defined(SO_PEERCRED) && \
 439         (defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || \
 440          (defined(HAVE_STRUCT_SOCKCRED) && defined(LOCAL_CREDS)))
 441                         if (port->raddr.addr.ss_family == AF_UNIX)
 442                         {
 443 #if defined(HAVE_STRUCT_FCRED) || defined(HAVE_STRUCT_SOCKCRED)
 444
 445                                 /*
 446                                  * Receive credentials on next message receipt, BSD/OS,
 447                                  * NetBSD. We need to set this before the client sends the
 448                                  * next packet.
 449                                  */
 450                                 int                     on = 1;
 451
 452                                 if (setsockopt(port->sock, 0, LOCAL_CREDS, &on, sizeof(on)) < 0)
 453                                         ereport(FATAL,
 454                                                         (errcode_for_socket_access(),
 455                                            errmsg("could not enable credential reception: %m")));
 456 #endif
 457
 458                                 sendAuthRequest(port, AUTH_REQ_SCM_CREDS);
 459                         }
 460 #endif
 461                         status = authident(port);
 462                         break;
 463
 464                 case uaMD5:
 465                         sendAuthRequest(port, AUTH_REQ_MD5);
 466                         status = recv_and_check_password_packet(port);
 467                         break;
 468
 469                 case uaCrypt:
 470                         sendAuthRequest(port, AUTH_REQ_CRYPT);
 471                         status = recv_and_check_password_packet(port);
 472                         break;
 473
 474                 case uaPassword:
 475                         sendAuthRequest(port, AUTH_REQ_PASSWORD);
 476                         status = recv_and_check_password_packet(port);
 477                         break;
 478
 479 #ifdef USE_PAM
 480                 case uaPAM:
 481                         pam_port_cludge = port;
 482                         status = CheckPAMAuth(port, port->user_name, "");
 483                         break;
 484 #endif   /* USE_PAM */
 485
 486 #ifdef USE_LDAP
 487                 case uaLDAP:
 488                         status = CheckLDAPAuth(port);
 489                         break;
 490 #endif
 491
 492                 case uaTrust:
 493                         status = STATUS_OK;
 494                         break;
 495         }
 496
 497         if (status == STATUS_OK)
 498                 sendAuthRequest(port, AUTH_REQ_OK);
 499         else
 500                 auth_failed(port, status);
 501 }
 502
 503
 504 /*
 505  * Send an authentication request packet to the frontend.
 506  */
 507 static void
 508 sendAuthRequest(Port *port, AuthRequest areq)
 509 {
 510         StringInfoData buf;
 511
 512         pq_beginmessage(&buf, 'R');
 513         pq_sendint(&buf, (int32) areq, sizeof(int32));
 514
 515         /* Add the salt for encrypted passwords. */
 516         if (areq == AUTH_REQ_MD5)
 517                 pq_sendbytes(&buf, port->md5Salt, 4);
 518         else if (areq == AUTH_REQ_CRYPT)
 519                 pq_sendbytes(&buf, port->cryptSalt, 2);
 520
 521         pq_endmessage(&buf);
 522
 523         /*
 524          * Flush message so client will see it, except for AUTH_REQ_OK, which need
 525          * not be sent until we are ready for queries.
 526          */
 527         if (areq != AUTH_REQ_OK)
 528                 pq_flush();
 529 }
 530
 531
 532 #ifdef USE_PAM
 533
 534 /*
 535  * PAM conversation function
 536  */
 537
 538 static int
 539 pam_passwd_conv_proc(int num_msg, const struct pam_message ** msg,
 540                                          struct pam_response ** resp, void *appdata_ptr)
 541 {
 542         if (num_msg != 1 || msg[0]->msg_style != PAM_PROMPT_ECHO_OFF)
 543         {
 544                 switch (msg[0]->msg_style)
 545                 {
 546                         case PAM_ERROR_MSG:
 547                                 ereport(LOG,
 548                                                 (errmsg("error from underlying PAM layer: %s",
 549                                                                 msg[0]->msg)));
 550                                 return PAM_CONV_ERR;
 551                         default:
 552                                 ereport(LOG,
 553                                                 (errmsg("unsupported PAM conversation %d/%s",
 554                                                                 msg[0]->msg_style, msg[0]->msg)));
 555                                 return PAM_CONV_ERR;
 556                 }
 557         }
 558
 559         if (!appdata_ptr)
 560         {
 561                 /*
 562                  * Workaround for Solaris 2.6 where the PAM library is broken and does
 563                  * not pass appdata_ptr to the conversation routine
 564                  */
 565                 appdata_ptr = pam_passwd;
 566         }
 567
 568         /*
 569          * Password wasn't passed to PAM the first time around - let's go ask the
 570          * client to send a password, which we then stuff into PAM.
 571          */
 572         if (strlen(appdata_ptr) == 0)
 573         {
 574                 char       *passwd;
 575
 576                 sendAuthRequest(pam_port_cludge, AUTH_REQ_PASSWORD);
 577                 passwd = recv_password_packet(pam_port_cludge);
 578
 579                 if (passwd == NULL)
 580                         return PAM_CONV_ERR;    /* client didn't want to send password */
 581
 582                 if (strlen(passwd) == 0)
 583                 {
 584                         ereport(LOG,
 585                                         (errmsg("empty password returned by client")));
 586                         return PAM_CONV_ERR;
 587                 }
 588                 appdata_ptr = passwd;
 589         }
 590
 591         /*
 592          * Explicitly not using palloc here - PAM will free this memory in
 593          * pam_end()
 594          */
 595         *resp = calloc(num_msg, sizeof(struct pam_response));
 596         if (!*resp)
 597         {
 598                 ereport(LOG,
 599                                 (errcode(ERRCODE_OUT_OF_MEMORY),
 600                                  errmsg("out of memory")));
 601                 return PAM_CONV_ERR;
 602         }
 603
 604         (*resp)[0].resp = strdup((char *) appdata_ptr);
 605         (*resp)[0].resp_retcode = 0;
 606
 607         return ((*resp)[0].resp ? PAM_SUCCESS : PAM_CONV_ERR);
 608 }
 609
 610
 611 /*
 612  * Check authentication against PAM.
 613  */
 614 static int
 615 CheckPAMAuth(Port *port, char *user, char *password)
 616 {
 617         int                     retval;
 618         pam_handle_t *pamh = NULL;
 619
 620         /*
 621          * Apparently, Solaris 2.6 is broken, and needs ugly static variable
 622          * workaround
 623          */
 624         pam_passwd = password;
 625
 626         /*
 627          * Set the application data portion of the conversation struct This is
 628          * later used inside the PAM conversation to pass the password to the
 629          * authentication module.
 630          */
 631         pam_passw_conv.appdata_ptr = (char *) password;         /* from password above,
 632                                                                                                                  * not allocated */
 633
 634         /* Optionally, one can set the service name in pg_hba.conf */
 635         if (port->auth_arg && port->auth_arg[0] != '\0')
 636                 retval = pam_start(port->auth_arg, "pgsql@",
 637                                                    &pam_passw_conv, &pamh);
 638         else
 639                 retval = pam_start(PGSQL_PAM_SERVICE, "pgsql@",
 640                                                    &pam_passw_conv, &pamh);
 641
 642         if (retval != PAM_SUCCESS)
 643         {
 644                 ereport(LOG,
 645                                 (errmsg("could not create PAM authenticator: %s",
 646                                                 pam_strerror(pamh, retval))));
 647                 pam_passwd = NULL;              /* Unset pam_passwd */
 648                 return STATUS_ERROR;
 649         }
 650
 651         retval = pam_set_item(pamh, PAM_USER, user);
 652
 653         if (retval != PAM_SUCCESS)
 654         {
 655                 ereport(LOG,
 656                                 (errmsg("pam_set_item(PAM_USER) failed: %s",
 657                                                 pam_strerror(pamh, retval))));
 658                 pam_passwd = NULL;              /* Unset pam_passwd */
 659                 return STATUS_ERROR;
 660         }
 661
 662         retval = pam_set_item(pamh, PAM_CONV, &pam_passw_conv);
 663
 664         if (retval != PAM_SUCCESS)
 665         {
 666                 ereport(LOG,
 667                                 (errmsg("pam_set_item(PAM_CONV) failed: %s",
 668                                                 pam_strerror(pamh, retval))));
 669                 pam_passwd = NULL;              /* Unset pam_passwd */
 670                 return STATUS_ERROR;
 671         }
 672
 673         retval = pam_authenticate(pamh, 0);
 674
 675         if (retval != PAM_SUCCESS)
 676         {
 677                 ereport(LOG,
 678                                 (errmsg("pam_authenticate failed: %s",
 679                                                 pam_strerror(pamh, retval))));
 680                 pam_passwd = NULL;              /* Unset pam_passwd */
 681                 return STATUS_ERROR;
 682         }
 683
 684         retval = pam_acct_mgmt(pamh, 0);
 685
 686         if (retval != PAM_SUCCESS)
 687         {
 688                 ereport(LOG,
 689                                 (errmsg("pam_acct_mgmt failed: %s",
 690                                                 pam_strerror(pamh, retval))));
 691                 pam_passwd = NULL;              /* Unset pam_passwd */
 692                 return STATUS_ERROR;
 693         }
 694
 695         retval = pam_end(pamh, retval);
 696
 697         if (retval != PAM_SUCCESS)
 698         {
 699                 ereport(LOG,
 700                                 (errmsg("could not release PAM authenticator: %s",
 701                                                 pam_strerror(pamh, retval))));
 702         }
 703
 704         pam_passwd = NULL;                      /* Unset pam_passwd */
 705
 706         return (retval == PAM_SUCCESS ? STATUS_OK : STATUS_ERROR);
 707 }
 708 #endif   /* USE_PAM */
 709
 710
 711 #ifdef USE_LDAP
 712
 713 static int
 714 CheckLDAPAuth(Port *port)
 715 {
 716         char       *passwd;
 717         char            server[128];
 718         char            basedn[128];
 719         char            prefix[128];
 720         char            suffix[128];
 721         LDAP       *ldap;
 722         bool            ssl = false;
 723         int                     r;
 724         int                     ldapversion = LDAP_VERSION3;
 725         int                     ldapport = LDAP_PORT;
 726         char            fulluser[NAMEDATALEN + 256 + 1];
 727
 728         if (!port->auth_arg || port->auth_arg[0] == '\0')
 729         {
 730                 ereport(LOG,
 731                                 (errmsg("LDAP configuration URL not specified")));
 732                 return STATUS_ERROR;
 733         }
 734
 735         /*
 736          * Crack the LDAP url. We do a very trivial parse..
 737          * ldap[s]://<server>[:<port>]/<basedn>[;prefix[;suffix]]
 738          */
 739
 740         server[0] = '\0';
 741         basedn[0] = '\0';
 742         prefix[0] = '\0';
 743         suffix[0] = '\0';
 744
 745         /* ldap, including port number */
 746         r = sscanf(port->auth_arg,
 747                            "ldap://%127[^:]:%i/%127[^;];%127[^;];%127s",
 748                            server, &ldapport, basedn, prefix, suffix);
 749         if (r < 3)
 750         {
 751                 /* ldaps, including port number */
 752                 r = sscanf(port->auth_arg,
 753                                    "ldaps://%127[^:]:%i/%127[^;];%127[^;];%127s",
 754                                    server, &ldapport, basedn, prefix, suffix);
 755                 if (r >= 3)
 756                         ssl = true;
 757         }
 758         if (r < 3)
 759         {
 760                 /* ldap, no port number */
 761                 r = sscanf(port->auth_arg,
 762                                    "ldap://%127[^/]/%127[^;];%127[^;];%127s",
 763                                    server, basedn, prefix, suffix);
 764         }
 765         if (r < 2)
 766         {
 767                 /* ldaps, no port number */
 768                 r = sscanf(port->auth_arg,
 769                                    "ldaps://%127[^/]/%127[^;];%127[^;];%127s",
 770                                    server, basedn, prefix, suffix);
 771                 if (r >= 2)
 772                         ssl = true;
 773         }
 774         if (r < 2)
 775         {
 776                 ereport(LOG,
 777                                 (errmsg("invalid LDAP URL: \"%s\"",
 778                                                 port->auth_arg)));
 779                 return STATUS_ERROR;
 780         }
 781
 782         sendAuthRequest(port, AUTH_REQ_PASSWORD);
 783
 784         passwd = recv_password_packet(port);
 785         if (passwd == NULL)
 786                 return STATUS_EOF;              /* client wouldn't send password */
 787
 788         ldap = ldap_init(server, ldapport);
 789         if (!ldap)
 790         {
 791 #ifndef WIN32
 792                 ereport(LOG,
 793                                 (errmsg("could not initialize LDAP: error code %d",
 794                                                 errno)));
 795 #else
 796                 ereport(LOG,
 797                                 (errmsg("could not initialize LDAP: error code %d",
 798                                                 (int) LdapGetLastError())));
 799 #endif
 800                 return STATUS_ERROR;
 801         }
 802
 803         if ((r = ldap_set_option(ldap, LDAP_OPT_PROTOCOL_VERSION, &ldapversion)) != LDAP_SUCCESS)
 804         {
 805                 ldap_unbind(ldap);
 806                 ereport(LOG,
 807                                 (errmsg("could not set LDAP protocol version: error code %d", r)));
 808                 return STATUS_ERROR;
 809         }
 810
 811         if (ssl)
 812         {
 813 #ifndef WIN32
 814                 if ((r = ldap_start_tls_s(ldap, NULL, NULL)) != LDAP_SUCCESS)
 815 #else
 816                 static __ldap_start_tls_sA _ldap_start_tls_sA = NULL;
 817
 818                 if (_ldap_start_tls_sA == NULL)
 819                 {
 820                         /*
 821                          * Need to load this function dynamically because it does not
 822                          * exist on Windows 2000, and causes a load error for the whole
 823                          * exe if referenced.
 824                          */
 825                         HANDLE          ldaphandle;
 826
 827                         ldaphandle = LoadLibrary("WLDAP32.DLL");
 828                         if (ldaphandle == NULL)
 829                         {
 830                                 /*
 831                                  * should never happen since we import other files from
 832                                  * wldap32, but check anyway
 833                                  */
 834                                 ldap_unbind(ldap);
 835                                 ereport(LOG,
 836                                                 (errmsg("could not load wldap32.dll")));
 837                                 return STATUS_ERROR;
 838                         }
 839                         _ldap_start_tls_sA = (__ldap_start_tls_sA) GetProcAddress(ldaphandle, "ldap_start_tls_sA");
 840                         if (_ldap_start_tls_sA == NULL)
 841                         {
 842                                 ldap_unbind(ldap);
 843                                 ereport(LOG,
 844                                                 (errmsg("could not load function _ldap_start_tls_sA in wldap32.dll"),
 845                                                  errdetail("LDAP over SSL is not supported on this platform.")));
 846                                 return STATUS_ERROR;
 847                         }
 848
 849                         /*
 850                          * Leak LDAP handle on purpose, because we need the library to stay
 851                          * open. This is ok because it will only ever be leaked once per
 852                          * process and is automatically cleaned up on process exit.
 853                          */
 854                 }
 855                 if ((r = _ldap_start_tls_sA(ldap, NULL, NULL, NULL, NULL)) != LDAP_SUCCESS)
 856 #endif
 857                 {
 858                         ldap_unbind(ldap);
 859                         ereport(LOG,
 860                                         (errmsg("could not start LDAP TLS session: error code %d", r)));
 861                         return STATUS_ERROR;
 862                 }
 863         }
 864
 865         snprintf(fulluser, sizeof(fulluser), "%s%s%s",
 866                          prefix, port->user_name, suffix);
 867         fulluser[sizeof(fulluser) - 1] = '\0';
 868
 869         r = ldap_simple_bind_s(ldap, fulluser, passwd);
 870         ldap_unbind(ldap);
 871
 872         if (r != LDAP_SUCCESS)
 873         {
 874                 ereport(LOG,
 875                                 (errmsg("LDAP login failed for user \"%s\" on server \"%s\": error code %d",
 876                                                 fulluser, server, r)));
 877                 return STATUS_ERROR;
 878         }
 879
 880         return STATUS_OK;
 881 }
 882 #endif   /* USE_LDAP */
 883
 884 /*
 885  * Collect password response packet from frontend.
 886  *
 887  * Returns NULL if couldn't get password, else palloc'd string.
 888  */
 889 static char *
 890 recv_password_packet(Port *port)
 891 {
 892         StringInfoData buf;
 893
 894         if (PG_PROTOCOL_MAJOR(port->proto) >= 3)
 895         {
 896                 /* Expect 'p' message type */
 897                 int                     mtype;
 898
 899                 mtype = pq_getbyte();
 900                 if (mtype != 'p')
 901                 {
 902                         /*
 903                          * If the client just disconnects without offering a password,
 904                          * don't make a log entry.  This is legal per protocol spec and in
 905                          * fact commonly done by psql, so complaining just clutters the
 906                          * log.
 907                          */
 908                         if (mtype != EOF)
 909                                 ereport(COMMERROR,
 910                                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
 911                                         errmsg("expected password response, got message type %d",
 912                                                    mtype)));
 913                         return NULL;            /* EOF or bad message type */
 914                 }
 915         }
 916         else
 917         {
 918                 /* For pre-3.0 clients, avoid log entry if they just disconnect */
 919                 if (pq_peekbyte() == EOF)
 920                         return NULL;            /* EOF */
 921         }
 922
 923         initStringInfo(&buf);
 924         if (pq_getmessage(&buf, 1000))          /* receive password */
 925         {
 926                 /* EOF - pq_getmessage already logged a suitable message */
 927                 pfree(buf.data);
 928                 return NULL;
 929         }
 930
 931         /*
 932          * Apply sanity check: password packet length should agree with length of
 933          * contained string.  Note it is safe to use strlen here because
 934          * StringInfo is guaranteed to have an appended '\0'.
 935          */
 936         if (strlen(buf.data) + 1 != buf.len)
 937                 ereport(COMMERROR,
 938                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
 939                                  errmsg("invalid password packet size")));
 940
 941         /* Do not echo password to logs, for security. */
 942         ereport(DEBUG5,
 943                         (errmsg("received password packet")));
 944
 945         /*
 946          * Return the received string.  Note we do not attempt to do any
 947          * character-set conversion on it; since we don't yet know the client's
 948          * encoding, there wouldn't be much point.
 949          */
 950         return buf.data;
 951 }
 952
 953
 954 /*
 955  * Called when we have sent an authorization request for a password.
 956  * Get the response and check it.
 957  */
 958 static int
 959 recv_and_check_password_packet(Port *port)
 960 {
 961         char       *passwd;
 962         int                     result;
 963
 964         passwd = recv_password_packet(port);
 965
 966         if (passwd == NULL)
 967                 return STATUS_EOF;              /* client wouldn't send password */
 968
 969         result = md5_crypt_verify(port, port->user_name, passwd);
 970
 971         pfree(passwd);
 972
 973         return result;
 974 }