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 1.147 2007/01/05 22:19:29 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         ret = pg_krb5_init();
 220         if (ret != STATUS_OK)
 221                 return ret;
 222
 223         retval = krb5_recvauth(pg_krb5_context, &auth_context,
 224                                                    (krb5_pointer) & port->sock, pg_krb_srvnam,
 225                                                    pg_krb5_server, 0, pg_krb5_keytab, &ticket);
 226         if (retval)
 227         {
 228                 ereport(LOG,
 229                                 (errmsg("Kerberos recvauth returned error %d",
 230                                                 retval)));
 231                 com_err("postgres", retval, "from krb5_recvauth");
 232                 return STATUS_ERROR;
 233         }
 234
 235         /*
 236          * The "client" structure comes out of the ticket and is therefore
 237          * authenticated.  Use it to check the username obtained from the
 238          * postmaster startup packet.
 239          *
 240          * I have no idea why this is considered necessary.
 241          */
 242 #if defined(HAVE_KRB5_TICKET_ENC_PART2)
 243         retval = krb5_unparse_name(pg_krb5_context,
 244                                                            ticket->enc_part2->client, &kusername);
 245 #elif defined(HAVE_KRB5_TICKET_CLIENT)
 246         retval = krb5_unparse_name(pg_krb5_context,
 247                                                            ticket->client, &kusername);
 248 #else
 249 #error "bogus configuration"
 250 #endif
 251         if (retval)
 252         {
 253                 ereport(LOG,
 254                                 (errmsg("Kerberos unparse_name returned error %d",
 255                                                 retval)));
 256                 com_err("postgres", retval, "while unparsing client name");
 257                 krb5_free_ticket(pg_krb5_context, ticket);
 258                 krb5_auth_con_free(pg_krb5_context, auth_context);
 259                 return STATUS_ERROR;
 260         }
 261
 262         kusername = pg_an_to_ln(kusername);
 263         if (pg_krb_caseins_users)
 264                 ret = pg_strncasecmp(port->user_name, kusername, SM_DATABASE_USER);
 265         else
 266                 ret = strncmp(port->user_name, kusername, SM_DATABASE_USER);
 267         if (ret)
 268         {
 269                 ereport(LOG,
 270                                 (errmsg("unexpected Kerberos user name received from client (received \"%s\", expected \"%s\")",
 271                                                 port->user_name, kusername)));
 272                 ret = STATUS_ERROR;
 273         }
 274         else
 275                 ret = STATUS_OK;
 276
 277         krb5_free_ticket(pg_krb5_context, ticket);
 278         krb5_auth_con_free(pg_krb5_context, auth_context);
 279         free(kusername);
 280
 281         return ret;
 282 }
 283 #else
 284
 285 static int
 286 pg_krb5_recvauth(Port *port)
 287 {
 288         ereport(LOG,
 289                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 290                          errmsg("Kerberos 5 not implemented on this server")));
 291         return STATUS_ERROR;
 292 }
 293 #endif   /* KRB5 */
 294
 295
 296 /*
 297  * Tell the user the authentication failed, but not (much about) why.
 298  *
 299  * There is a tradeoff here between security concerns and making life
 300  * unnecessarily difficult for legitimate users.  We would not, for example,
 301  * want to report the password we were expecting to receive...
 302  * But it seems useful to report the username and authorization method
 303  * in use, and these are items that must be presumed known to an attacker
 304  * anyway.
 305  * Note that many sorts of failure report additional information in the
 306  * postmaster log, which we hope is only readable by good guys.
 307  */
 308 static void
 309 auth_failed(Port *port, int status)
 310 {
 311         const char *errstr;
 312
 313         /*
 314          * If we failed due to EOF from client, just quit; there's no point in
 315          * trying to send a message to the client, and not much point in logging
 316          * the failure in the postmaster log.  (Logging the failure might be
 317          * desirable, were it not for the fact that libpq closes the connection
 318          * unceremoniously if challenged for a password when it hasn't got one to
 319          * send.  We'll get a useless log entry for every psql connection under
 320          * password auth, even if it's perfectly successful, if we log STATUS_EOF
 321          * events.)
 322          */
 323         if (status == STATUS_EOF)
 324                 proc_exit(0);
 325
 326         switch (port->auth_method)
 327         {
 328                 case uaReject:
 329                         errstr = gettext_noop("authentication failed for user \"%s\": host rejected");
 330                         break;
 331                 case uaKrb5:
 332                         errstr = gettext_noop("Kerberos 5 authentication failed for user \"%s\"");
 333                         break;
 334                 case uaTrust:
 335                         errstr = gettext_noop("\"trust\" authentication failed for user \"%s\"");
 336                         break;
 337                 case uaIdent:
 338                         errstr = gettext_noop("Ident authentication failed for user \"%s\"");
 339                         break;
 340                 case uaMD5:
 341                 case uaCrypt:
 342                 case uaPassword:
 343                         errstr = gettext_noop("password authentication failed for user \"%s\"");
 344                         break;
 345 #ifdef USE_PAM
 346                 case uaPAM:
 347                         errstr = gettext_noop("PAM authentication failed for user \"%s\"");
 348                         break;
 349 #endif   /* USE_PAM */
 350 #ifdef USE_LDAP
 351                 case uaLDAP:
 352                         errstr = gettext_noop("LDAP authentication failed for user \"%s\"");
 353                         break;
 354 #endif   /* USE_LDAP */
 355                 default:
 356                         errstr = gettext_noop("authentication failed for user \"%s\": invalid authentication method");
 357                         break;
 358         }
 359
 360         ereport(FATAL,
 361                         (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
 362                          errmsg(errstr, port->user_name)));
 363         /* doesn't return */
 364 }
 365
 366
 367 /*
 368  * Client authentication starts here.  If there is an error, this
 369  * function does not return and the backend process is terminated.
 370  */
 371 void
 372 ClientAuthentication(Port *port)
 373 {
 374         int                     status = STATUS_ERROR;
 375
 376         /*
 377          * Get the authentication method to use for this frontend/database
 378          * combination.  Note: a failure return indicates a problem with the hba
 379          * config file, not with the request.  hba.c should have dropped an error
 380          * message into the postmaster logfile if it failed.
 381          */
 382         if (hba_getauthmethod(port) != STATUS_OK)
 383                 ereport(FATAL,
 384                                 (errcode(ERRCODE_CONFIG_FILE_ERROR),
 385                                  errmsg("missing or erroneous pg_hba.conf file"),
 386                                  errhint("See server log for details.")));
 387
 388         switch (port->auth_method)
 389         {
 390                 case uaReject:
 391
 392                         /*
 393                          * This could have come from an explicit "reject" entry in
 394                          * pg_hba.conf, but more likely it means there was no matching
 395                          * entry.  Take pity on the poor user and issue a helpful error
 396                          * message.  NOTE: this is not a security breach, because all the
 397                          * info reported here is known at the frontend and must be assumed
 398                          * known to bad guys. We're merely helping out the less clueful
 399                          * good guys.
 400                          */
 401                         {
 402                                 char            hostinfo[NI_MAXHOST];
 403
 404                                 pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
 405                                                                    hostinfo, sizeof(hostinfo),
 406                                                                    NULL, 0,
 407                                                                    NI_NUMERICHOST);
 408
 409 #ifdef USE_SSL
 410                                 ereport(FATAL,
 411                                                 (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
 412                                                  errmsg("no pg_hba.conf entry for host \"%s\", user \"%s\", database \"%s\", %s",
 413                                                           hostinfo, port->user_name, port->database_name,
 414                                                                 port->ssl ? _("SSL on") : _("SSL off"))));
 415 #else
 416                                 ereport(FATAL,
 417                                                 (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
 418                                                  errmsg("no pg_hba.conf entry for host \"%s\", user \"%s\", database \"%s\"",
 419                                                    hostinfo, port->user_name, port->database_name)));
 420 #endif
 421                                 break;
 422                         }
 423
 424                 case uaKrb5:
 425                         sendAuthRequest(port, AUTH_REQ_KRB5);
 426                         status = pg_krb5_recvauth(port);
 427                         break;
 428
 429                 case uaIdent:
 430
 431                         /*
 432                          * If we are doing ident on unix-domain sockets, use SCM_CREDS
 433                          * only if it is defined and SO_PEERCRED isn't.
 434                          */
 435 #if !defined(HAVE_GETPEEREID) && !defined(SO_PEERCRED) && \
 436         (defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || \
 437          (defined(HAVE_STRUCT_SOCKCRED) && defined(LOCAL_CREDS)))
 438                         if (port->raddr.addr.ss_family == AF_UNIX)
 439                         {
 440 #if defined(HAVE_STRUCT_FCRED) || defined(HAVE_STRUCT_SOCKCRED)
 441
 442                                 /*
 443                                  * Receive credentials on next message receipt, BSD/OS,
 444                                  * NetBSD. We need to set this before the client sends the
 445                                  * next packet.
 446                                  */
 447                                 int                     on = 1;
 448
 449                                 if (setsockopt(port->sock, 0, LOCAL_CREDS, &on, sizeof(on)) < 0)
 450                                         ereport(FATAL,
 451                                                         (errcode_for_socket_access(),
 452                                            errmsg("could not enable credential reception: %m")));
 453 #endif
 454
 455                                 sendAuthRequest(port, AUTH_REQ_SCM_CREDS);
 456                         }
 457 #endif
 458                         status = authident(port);
 459                         break;
 460
 461                 case uaMD5:
 462                         sendAuthRequest(port, AUTH_REQ_MD5);
 463                         status = recv_and_check_password_packet(port);
 464                         break;
 465
 466                 case uaCrypt:
 467                         sendAuthRequest(port, AUTH_REQ_CRYPT);
 468                         status = recv_and_check_password_packet(port);
 469                         break;
 470
 471                 case uaPassword:
 472                         sendAuthRequest(port, AUTH_REQ_PASSWORD);
 473                         status = recv_and_check_password_packet(port);
 474                         break;
 475
 476 #ifdef USE_PAM
 477                 case uaPAM:
 478                         pam_port_cludge = port;
 479                         status = CheckPAMAuth(port, port->user_name, "");
 480                         break;
 481 #endif   /* USE_PAM */
 482
 483 #ifdef USE_LDAP
 484                 case uaLDAP:
 485                         status = CheckLDAPAuth(port);
 486                         break;
 487 #endif
 488
 489                 case uaTrust:
 490                         status = STATUS_OK;
 491                         break;
 492         }
 493
 494         if (status == STATUS_OK)
 495                 sendAuthRequest(port, AUTH_REQ_OK);
 496         else
 497                 auth_failed(port, status);
 498 }
 499
 500
 501 /*
 502  * Send an authentication request packet to the frontend.
 503  */
 504 static void
 505 sendAuthRequest(Port *port, AuthRequest areq)
 506 {
 507         StringInfoData buf;
 508
 509         pq_beginmessage(&buf, 'R');
 510         pq_sendint(&buf, (int32) areq, sizeof(int32));
 511
 512         /* Add the salt for encrypted passwords. */
 513         if (areq == AUTH_REQ_MD5)
 514                 pq_sendbytes(&buf, port->md5Salt, 4);
 515         else if (areq == AUTH_REQ_CRYPT)
 516                 pq_sendbytes(&buf, port->cryptSalt, 2);
 517
 518         pq_endmessage(&buf);
 519
 520         /*
 521          * Flush message so client will see it, except for AUTH_REQ_OK, which need
 522          * not be sent until we are ready for queries.
 523          */
 524         if (areq != AUTH_REQ_OK)
 525                 pq_flush();
 526 }
 527
 528
 529 #ifdef USE_PAM
 530
 531 /*
 532  * PAM conversation function
 533  */
 534
 535 static int
 536 pam_passwd_conv_proc(int num_msg, const struct pam_message ** msg,
 537                                          struct pam_response ** resp, void *appdata_ptr)
 538 {
 539         if (num_msg != 1 || msg[0]->msg_style != PAM_PROMPT_ECHO_OFF)
 540         {
 541                 switch (msg[0]->msg_style)
 542                 {
 543                         case PAM_ERROR_MSG:
 544                                 ereport(LOG,
 545                                                 (errmsg("error from underlying PAM layer: %s",
 546                                                                 msg[0]->msg)));
 547                                 return PAM_CONV_ERR;
 548                         default:
 549                                 ereport(LOG,
 550                                                 (errmsg("unsupported PAM conversation %d/%s",
 551                                                                 msg[0]->msg_style, msg[0]->msg)));
 552                                 return PAM_CONV_ERR;
 553                 }
 554         }
 555
 556         if (!appdata_ptr)
 557         {
 558                 /*
 559                  * Workaround for Solaris 2.6 where the PAM library is broken and does
 560                  * not pass appdata_ptr to the conversation routine
 561                  */
 562                 appdata_ptr = pam_passwd;
 563         }
 564
 565         /*
 566          * Password wasn't passed to PAM the first time around - let's go ask the
 567          * client to send a password, which we then stuff into PAM.
 568          */
 569         if (strlen(appdata_ptr) == 0)
 570         {
 571                 char       *passwd;
 572
 573                 sendAuthRequest(pam_port_cludge, AUTH_REQ_PASSWORD);
 574                 passwd = recv_password_packet(pam_port_cludge);
 575
 576                 if (passwd == NULL)
 577                         return PAM_CONV_ERR;    /* client didn't want to send password */
 578
 579                 if (strlen(passwd) == 0)
 580                 {
 581                         ereport(LOG,
 582                                         (errmsg("empty password returned by client")));
 583                         return PAM_CONV_ERR;
 584                 }
 585                 appdata_ptr = passwd;
 586         }
 587
 588         /*
 589          * Explicitly not using palloc here - PAM will free this memory in
 590          * pam_end()
 591          */
 592         *resp = calloc(num_msg, sizeof(struct pam_response));
 593         if (!*resp)
 594         {
 595                 ereport(LOG,
 596                                 (errcode(ERRCODE_OUT_OF_MEMORY),
 597                                  errmsg("out of memory")));
 598                 return PAM_CONV_ERR;
 599         }
 600
 601         (*resp)[0].resp = strdup((char *) appdata_ptr);
 602         (*resp)[0].resp_retcode = 0;
 603
 604         return ((*resp)[0].resp ? PAM_SUCCESS : PAM_CONV_ERR);
 605 }
 606
 607
 608 /*
 609  * Check authentication against PAM.
 610  */
 611 static int
 612 CheckPAMAuth(Port *port, char *user, char *password)
 613 {
 614         int                     retval;
 615         pam_handle_t *pamh = NULL;
 616
 617         /*
 618          * Apparently, Solaris 2.6 is broken, and needs ugly static variable
 619          * workaround
 620          */
 621         pam_passwd = password;
 622
 623         /*
 624          * Set the application data portion of the conversation struct This is
 625          * later used inside the PAM conversation to pass the password to the
 626          * authentication module.
 627          */
 628         pam_passw_conv.appdata_ptr = (char *) password;         /* from password above,
 629                                                                                                                  * not allocated */
 630
 631         /* Optionally, one can set the service name in pg_hba.conf */
 632         if (port->auth_arg && port->auth_arg[0] != '\0')
 633                 retval = pam_start(port->auth_arg, "pgsql@",
 634                                                    &pam_passw_conv, &pamh);
 635         else
 636                 retval = pam_start(PGSQL_PAM_SERVICE, "pgsql@",
 637                                                    &pam_passw_conv, &pamh);
 638
 639         if (retval != PAM_SUCCESS)
 640         {
 641                 ereport(LOG,
 642                                 (errmsg("could not create PAM authenticator: %s",
 643                                                 pam_strerror(pamh, retval))));
 644                 pam_passwd = NULL;              /* Unset pam_passwd */
 645                 return STATUS_ERROR;
 646         }
 647
 648         retval = pam_set_item(pamh, PAM_USER, user);
 649
 650         if (retval != PAM_SUCCESS)
 651         {
 652                 ereport(LOG,
 653                                 (errmsg("pam_set_item(PAM_USER) failed: %s",
 654                                                 pam_strerror(pamh, retval))));
 655                 pam_passwd = NULL;              /* Unset pam_passwd */
 656                 return STATUS_ERROR;
 657         }
 658
 659         retval = pam_set_item(pamh, PAM_CONV, &pam_passw_conv);
 660
 661         if (retval != PAM_SUCCESS)
 662         {
 663                 ereport(LOG,
 664                                 (errmsg("pam_set_item(PAM_CONV) failed: %s",
 665                                                 pam_strerror(pamh, retval))));
 666                 pam_passwd = NULL;              /* Unset pam_passwd */
 667                 return STATUS_ERROR;
 668         }
 669
 670         retval = pam_authenticate(pamh, 0);
 671
 672         if (retval != PAM_SUCCESS)
 673         {
 674                 ereport(LOG,
 675                                 (errmsg("pam_authenticate failed: %s",
 676                                                 pam_strerror(pamh, retval))));
 677                 pam_passwd = NULL;              /* Unset pam_passwd */
 678                 return STATUS_ERROR;
 679         }
 680
 681         retval = pam_acct_mgmt(pamh, 0);
 682
 683         if (retval != PAM_SUCCESS)
 684         {
 685                 ereport(LOG,
 686                                 (errmsg("pam_acct_mgmt failed: %s",
 687                                                 pam_strerror(pamh, retval))));
 688                 pam_passwd = NULL;              /* Unset pam_passwd */
 689                 return STATUS_ERROR;
 690         }
 691
 692         retval = pam_end(pamh, retval);
 693
 694         if (retval != PAM_SUCCESS)
 695         {
 696                 ereport(LOG,
 697                                 (errmsg("could not release PAM authenticator: %s",
 698                                                 pam_strerror(pamh, retval))));
 699         }
 700
 701         pam_passwd = NULL;                      /* Unset pam_passwd */
 702
 703         return (retval == PAM_SUCCESS ? STATUS_OK : STATUS_ERROR);
 704 }
 705 #endif   /* USE_PAM */
 706
 707
 708 #ifdef USE_LDAP
 709
 710 static int
 711 CheckLDAPAuth(Port *port)
 712 {
 713         char       *passwd;
 714         char            server[128];
 715         char            basedn[128];
 716         char            prefix[128];
 717         char            suffix[128];
 718         LDAP       *ldap;
 719         bool            ssl = false;
 720         int                     r;
 721         int                     ldapversion = LDAP_VERSION3;
 722         int                     ldapport = LDAP_PORT;
 723         char            fulluser[NAMEDATALEN + 256 + 1];
 724
 725         if (!port->auth_arg || port->auth_arg[0] == '\0')
 726         {
 727                 ereport(LOG,
 728                                 (errmsg("LDAP configuration URL not specified")));
 729                 return STATUS_ERROR;
 730         }
 731
 732         /*
 733          * Crack the LDAP url. We do a very trivial parse..
 734          * ldap[s]://<server>[:<port>]/<basedn>[;prefix[;suffix]]
 735          */
 736
 737         server[0] = '\0';
 738         basedn[0] = '\0';
 739         prefix[0] = '\0';
 740         suffix[0] = '\0';
 741
 742         /* ldap, including port number */
 743         r = sscanf(port->auth_arg,
 744                            "ldap://%127[^:]:%i/%127[^;];%127[^;];%127s",
 745                            server, &ldapport, basedn, prefix, suffix);
 746         if (r < 3)
 747         {
 748                 /* ldaps, including port number */
 749                 r = sscanf(port->auth_arg,
 750                                    "ldaps://%127[^:]:%i/%127[^;];%127[^;];%127s",
 751                                    server, &ldapport, basedn, prefix, suffix);
 752                 if (r >= 3)
 753                         ssl = true;
 754         }
 755         if (r < 3)
 756         {
 757                 /* ldap, no port number */
 758                 r = sscanf(port->auth_arg,
 759                                    "ldap://%127[^/]/%127[^;];%127[^;];%127s",
 760                                    server, basedn, prefix, suffix);
 761         }
 762         if (r < 2)
 763         {
 764                 /* ldaps, no port number */
 765                 r = sscanf(port->auth_arg,
 766                                    "ldaps://%127[^/]/%127[^;];%127[^;];%127s",
 767                                    server, basedn, prefix, suffix);
 768                 if (r >= 2)
 769                         ssl = true;
 770         }
 771         if (r < 2)
 772         {
 773                 ereport(LOG,
 774                                 (errmsg("invalid LDAP URL: \"%s\"",
 775                                                 port->auth_arg)));
 776                 return STATUS_ERROR;
 777         }
 778
 779         sendAuthRequest(port, AUTH_REQ_PASSWORD);
 780
 781         passwd = recv_password_packet(port);
 782         if (passwd == NULL)
 783                 return STATUS_EOF;              /* client wouldn't send password */
 784
 785         ldap = ldap_init(server, ldapport);
 786         if (!ldap)
 787         {
 788 #ifndef WIN32
 789                 ereport(LOG,
 790                                 (errmsg("could not initialize LDAP: error code %d",
 791                                                 errno)));
 792 #else
 793                 ereport(LOG,
 794                                 (errmsg("could not initialize LDAP: error code %d",
 795                                                 (int) LdapGetLastError())));
 796 #endif
 797                 return STATUS_ERROR;
 798         }
 799
 800         if ((r = ldap_set_option(ldap, LDAP_OPT_PROTOCOL_VERSION, &ldapversion)) != LDAP_SUCCESS)
 801         {
 802                 ldap_unbind(ldap);
 803                 ereport(LOG,
 804                                 (errmsg("could not set LDAP protocol version: error code %d", r)));
 805                 return STATUS_ERROR;
 806         }
 807
 808         if (ssl)
 809         {
 810 #ifndef WIN32
 811                 if ((r = ldap_start_tls_s(ldap, NULL, NULL)) != LDAP_SUCCESS)
 812 #else
 813                 static __ldap_start_tls_sA _ldap_start_tls_sA = NULL;
 814
 815                 if (_ldap_start_tls_sA == NULL)
 816                 {
 817                         /*
 818                          * Need to load this function dynamically because it does not
 819                          * exist on Windows 2000, and causes a load error for the whole
 820                          * exe if referenced.
 821                          */
 822                         HANDLE          ldaphandle;
 823
 824                         ldaphandle = LoadLibrary("WLDAP32.DLL");
 825                         if (ldaphandle == NULL)
 826                         {
 827                                 /*
 828                                  * should never happen since we import other files from
 829                                  * wldap32, but check anyway
 830                                  */
 831                                 ldap_unbind(ldap);
 832                                 ereport(LOG,
 833                                                 (errmsg("could not load wldap32.dll")));
 834                                 return STATUS_ERROR;
 835                         }
 836                         _ldap_start_tls_sA = (__ldap_start_tls_sA) GetProcAddress(ldaphandle, "ldap_start_tls_sA");
 837                         if (_ldap_start_tls_sA == NULL)
 838                         {
 839                                 ldap_unbind(ldap);
 840                                 ereport(LOG,
 841                                                 (errmsg("could not load function _ldap_start_tls_sA in wldap32.dll"),
 842                                                  errdetail("LDAP over SSL is not supported on this platform.")));
 843                                 return STATUS_ERROR;
 844                         }
 845
 846                         /*
 847                          * Leak LDAP handle on purpose, because we need the library to stay
 848                          * open. This is ok because it will only ever be leaked once per
 849                          * process and is automatically cleaned up on process exit.
 850                          */
 851                 }
 852                 if ((r = _ldap_start_tls_sA(ldap, NULL, NULL, NULL, NULL)) != LDAP_SUCCESS)
 853 #endif
 854                 {
 855                         ldap_unbind(ldap);
 856                         ereport(LOG,
 857                                         (errmsg("could not start LDAP TLS session: error code %d", r)));
 858                         return STATUS_ERROR;
 859                 }
 860         }
 861
 862         snprintf(fulluser, sizeof(fulluser), "%s%s%s",
 863                          prefix, port->user_name, suffix);
 864         fulluser[sizeof(fulluser) - 1] = '\0';
 865
 866         r = ldap_simple_bind_s(ldap, fulluser, passwd);
 867         ldap_unbind(ldap);
 868
 869         if (r != LDAP_SUCCESS)
 870         {
 871                 ereport(LOG,
 872                                 (errmsg("LDAP login failed for user \"%s\" on server \"%s\": error code %d",
 873                                                 fulluser, server, r)));
 874                 return STATUS_ERROR;
 875         }
 876
 877         return STATUS_OK;
 878 }
 879 #endif   /* USE_LDAP */
 880
 881 /*
 882  * Collect password response packet from frontend.
 883  *
 884  * Returns NULL if couldn't get password, else palloc'd string.
 885  */
 886 static char *
 887 recv_password_packet(Port *port)
 888 {
 889         StringInfoData buf;
 890
 891         if (PG_PROTOCOL_MAJOR(port->proto) >= 3)
 892         {
 893                 /* Expect 'p' message type */
 894                 int                     mtype;
 895
 896                 mtype = pq_getbyte();
 897                 if (mtype != 'p')
 898                 {
 899                         /*
 900                          * If the client just disconnects without offering a password,
 901                          * don't make a log entry.  This is legal per protocol spec and in
 902                          * fact commonly done by psql, so complaining just clutters the
 903                          * log.
 904                          */
 905                         if (mtype != EOF)
 906                                 ereport(COMMERROR,
 907                                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
 908                                         errmsg("expected password response, got message type %d",
 909                                                    mtype)));
 910                         return NULL;            /* EOF or bad message type */
 911                 }
 912         }
 913         else
 914         {
 915                 /* For pre-3.0 clients, avoid log entry if they just disconnect */
 916                 if (pq_peekbyte() == EOF)
 917                         return NULL;            /* EOF */
 918         }
 919
 920         initStringInfo(&buf);
 921         if (pq_getmessage(&buf, 1000))          /* receive password */
 922         {
 923                 /* EOF - pq_getmessage already logged a suitable message */
 924                 pfree(buf.data);
 925                 return NULL;
 926         }
 927
 928         /*
 929          * Apply sanity check: password packet length should agree with length of
 930          * contained string.  Note it is safe to use strlen here because
 931          * StringInfo is guaranteed to have an appended '\0'.
 932          */
 933         if (strlen(buf.data) + 1 != buf.len)
 934                 ereport(COMMERROR,
 935                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
 936                                  errmsg("invalid password packet size")));
 937
 938         /* Do not echo password to logs, for security. */
 939         ereport(DEBUG5,
 940                         (errmsg("received password packet")));
 941
 942         /*
 943          * Return the received string.  Note we do not attempt to do any
 944          * character-set conversion on it; since we don't yet know the client's
 945          * encoding, there wouldn't be much point.
 946          */
 947         return buf.data;
 948 }
 949
 950
 951 /*
 952  * Called when we have sent an authorization request for a password.
 953  * Get the response and check it.
 954  */
 955 static int
 956 recv_and_check_password_packet(Port *port)
 957 {
 958         char       *passwd;
 959         int                     result;
 960
 961         passwd = recv_password_packet(port);
 962
 963         if (passwd == NULL)
 964                 return STATUS_EOF;              /* client wouldn't send password */
 965
 966         result = md5_crypt_verify(port, port->user_name, passwd);
 967
 968         pfree(passwd);
 969
 970         return result;
 971 }