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 1.155 2007/07/24 09:00:27 mha 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 #include <unistd.h>
  27
  28 #include "libpq/auth.h"
  29 #include "libpq/crypt.h"
  30 #include "libpq/ip.h"
  31 #include "libpq/libpq.h"
  32 #include "libpq/pqformat.h"
  33 #include "storage/ipc.h"
  34
  35
  36 static void sendAuthRequest(Port *port, AuthRequest areq);
  37 static void auth_failed(Port *port, int status);
  38 static char *recv_password_packet(Port *port);
  39 static int      recv_and_check_password_packet(Port *port);
  40
  41 char       *pg_krb_server_keyfile;
  42 char       *pg_krb_srvnam;
  43 bool            pg_krb_caseins_users;
  44 char       *pg_krb_server_hostname = NULL;
  45
  46 #ifdef USE_PAM
  47 #ifdef HAVE_PAM_PAM_APPL_H
  48 #include <pam/pam_appl.h>
  49 #endif
  50 #ifdef HAVE_SECURITY_PAM_APPL_H
  51 #include <security/pam_appl.h>
  52 #endif
  53
  54 #define PGSQL_PAM_SERVICE "postgresql"  /* Service name passed to PAM */
  55
  56 static int      CheckPAMAuth(Port *port, char *user, char *password);
  57 static int pam_passwd_conv_proc(int num_msg, const struct pam_message ** msg,
  58                                          struct pam_response ** resp, void *appdata_ptr);
  59
  60 static struct pam_conv pam_passw_conv = {
  61         &pam_passwd_conv_proc,
  62         NULL
  63 };
  64
  65 static char *pam_passwd = NULL; /* Workaround for Solaris 2.6 brokenness */
  66 static Port *pam_port_cludge;   /* Workaround for passing "Port *port" into
  67                                                                  * pam_passwd_conv_proc */
  68 #endif   /* USE_PAM */
  69
  70 #ifdef USE_LDAP
  71 #ifndef WIN32
  72 /* We use a deprecated function to keep the codepath the same as win32. */
  73 #define LDAP_DEPRECATED 1
  74 #include <ldap.h>
  75 #else
  76 #include <winldap.h>
  77
  78 /* Correct header from the Platform SDK */
  79 typedef
  80 ULONG(*__ldap_start_tls_sA) (
  81                                                          IN PLDAP ExternalHandle,
  82                                                          OUT PULONG ServerReturnValue,
  83                                                          OUT LDAPMessage ** result,
  84                                                          IN PLDAPControlA * ServerControls,
  85                                                          IN PLDAPControlA * ClientControls
  86 );
  87 #endif
  88
  89 static int      CheckLDAPAuth(Port *port);
  90 #endif
  91
  92
  93 #ifdef KRB5
  94 /*----------------------------------------------------------------
  95  * MIT Kerberos authentication system - protocol version 5
  96  *----------------------------------------------------------------
  97  */
  98
  99 #include <krb5.h>
 100 /* Some old versions of Kerberos do not include <com_err.h> in <krb5.h> */
 101 #if !defined(__COM_ERR_H) && !defined(__COM_ERR_H__)
 102 #include <com_err.h>
 103 #endif
 104
 105 /*
 106  * pg_an_to_ln -- return the local name corresponding to an authentication
 107  *                                name
 108  *
 109  * XXX Assumes that the first aname component is the user name.  This is NOT
 110  *         necessarily so, since an aname can actually be something out of your
 111  *         worst X.400 nightmare, like
 112  *                ORGANIZATION=U. C. Berkeley/NAME=Paul M. Aoki@CS.BERKELEY.EDU
 113  *         Note that the MIT an_to_ln code does the same thing if you don't
 114  *         provide an aname mapping database...it may be a better idea to use
 115  *         krb5_an_to_ln, except that it punts if multiple components are found,
 116  *         and we can't afford to punt.
 117  */
 118 static char *
 119 pg_an_to_ln(char *aname)
 120 {
 121         char       *p;
 122
 123         if ((p = strchr(aname, '/')) || (p = strchr(aname, '@')))
 124                 *p = '\0';
 125         return aname;
 126 }
 127
 128
 129 /*
 130  * Various krb5 state which is not connection specfic, and a flag to
 131  * indicate whether we have initialised it yet.
 132  */
 133 static int      pg_krb5_initialised;
 134 static krb5_context pg_krb5_context;
 135 static krb5_keytab pg_krb5_keytab;
 136 static krb5_principal pg_krb5_server;
 137
 138
 139 static int
 140 pg_krb5_init(void)
 141 {
 142         krb5_error_code retval;
 143         char       *khostname;
 144
 145         if (pg_krb5_initialised)
 146                 return STATUS_OK;
 147
 148         retval = krb5_init_context(&pg_krb5_context);
 149         if (retval)
 150         {
 151                 ereport(LOG,
 152                                 (errmsg("Kerberos initialization returned error %d",
 153                                                 retval)));
 154                 com_err("postgres", retval, "while initializing krb5");
 155                 return STATUS_ERROR;
 156         }
 157
 158         retval = krb5_kt_resolve(pg_krb5_context, pg_krb_server_keyfile, &pg_krb5_keytab);
 159         if (retval)
 160         {
 161                 ereport(LOG,
 162                                 (errmsg("Kerberos keytab resolving returned error %d",
 163                                                 retval)));
 164                 com_err("postgres", retval, "while resolving keytab file \"%s\"",
 165                                 pg_krb_server_keyfile);
 166                 krb5_free_context(pg_krb5_context);
 167                 return STATUS_ERROR;
 168         }
 169
 170         /*
 171          * If no hostname was specified, pg_krb_server_hostname is already NULL.
 172          * If it's set to blank, force it to NULL.
 173          */
 174         khostname = pg_krb_server_hostname;
 175         if (khostname && khostname[0] == '\0')
 176                 khostname = NULL;
 177
 178         retval = krb5_sname_to_principal(pg_krb5_context,
 179                                                                          khostname,
 180                                                                          pg_krb_srvnam,
 181                                                                          KRB5_NT_SRV_HST,
 182                                                                          &pg_krb5_server);
 183         if (retval)
 184         {
 185                 ereport(LOG,
 186                                 (errmsg("Kerberos sname_to_principal(\"%s\", \"%s\") returned error %d",
 187                  khostname ? khostname : "server hostname", pg_krb_srvnam, retval)));
 188                 com_err("postgres", retval,
 189                 "while getting server principal for server \"%s\" for service \"%s\"",
 190                                 khostname ? khostname : "server hostname", pg_krb_srvnam);
 191                 krb5_kt_close(pg_krb5_context, pg_krb5_keytab);
 192                 krb5_free_context(pg_krb5_context);
 193                 return STATUS_ERROR;
 194         }
 195
 196         pg_krb5_initialised = 1;
 197         return STATUS_OK;
 198 }
 199
 200
 201 /*
 202  * pg_krb5_recvauth -- server routine to receive authentication information
 203  *                                         from the client
 204  *
 205  * We still need to compare the username obtained from the client's setup
 206  * packet to the authenticated name.
 207  *
 208  * We have our own keytab file because postgres is unlikely to run as root,
 209  * and so cannot read the default keytab.
 210  */
 211 static int
 212 pg_krb5_recvauth(Port *port)
 213 {
 214         krb5_error_code retval;
 215         int                     ret;
 216         krb5_auth_context auth_context = NULL;
 217         krb5_ticket *ticket;
 218         char       *kusername;
 219
 220         if (get_role_line(port->user_name) == NULL)
 221                 return STATUS_ERROR;
 222
 223         ret = pg_krb5_init();
 224         if (ret != STATUS_OK)
 225                 return ret;
 226
 227         retval = krb5_recvauth(pg_krb5_context, &auth_context,
 228                                                    (krb5_pointer) & port->sock, pg_krb_srvnam,
 229                                                    pg_krb5_server, 0, pg_krb5_keytab, &ticket);
 230         if (retval)
 231         {
 232                 ereport(LOG,
 233                                 (errmsg("Kerberos recvauth returned error %d",
 234                                                 retval)));
 235                 com_err("postgres", retval, "from krb5_recvauth");
 236                 return STATUS_ERROR;
 237         }
 238
 239         /*
 240          * The "client" structure comes out of the ticket and is therefore
 241          * authenticated.  Use it to check the username obtained from the
 242          * postmaster startup packet.
 243          *
 244          * I have no idea why this is considered necessary.
 245          */
 246 #if defined(HAVE_KRB5_TICKET_ENC_PART2)
 247         retval = krb5_unparse_name(pg_krb5_context,
 248                                                            ticket->enc_part2->client, &kusername);
 249 #elif defined(HAVE_KRB5_TICKET_CLIENT)
 250         retval = krb5_unparse_name(pg_krb5_context,
 251                                                            ticket->client, &kusername);
 252 #else
 253 #error "bogus configuration"
 254 #endif
 255         if (retval)
 256         {
 257                 ereport(LOG,
 258                                 (errmsg("Kerberos unparse_name returned error %d",
 259                                                 retval)));
 260                 com_err("postgres", retval, "while unparsing client name");
 261                 krb5_free_ticket(pg_krb5_context, ticket);
 262                 krb5_auth_con_free(pg_krb5_context, auth_context);
 263                 return STATUS_ERROR;
 264         }
 265
 266         kusername = pg_an_to_ln(kusername);
 267         if (pg_krb_caseins_users)
 268                 ret = pg_strncasecmp(port->user_name, kusername, SM_DATABASE_USER);
 269         else
 270                 ret = strncmp(port->user_name, kusername, SM_DATABASE_USER);
 271         if (ret)
 272         {
 273                 ereport(LOG,
 274                                 (errmsg("unexpected Kerberos user name received from client (received \"%s\", expected \"%s\")",
 275                                                 port->user_name, kusername)));
 276                 ret = STATUS_ERROR;
 277         }
 278         else
 279                 ret = STATUS_OK;
 280
 281         krb5_free_ticket(pg_krb5_context, ticket);
 282         krb5_auth_con_free(pg_krb5_context, auth_context);
 283         free(kusername);
 284
 285         return ret;
 286 }
 287 #else
 288
 289 static int
 290 pg_krb5_recvauth(Port *port)
 291 {
 292         ereport(LOG,
 293                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 294                          errmsg("Kerberos 5 not implemented on this server")));
 295         return STATUS_ERROR;
 296 }
 297 #endif   /* KRB5 */
 298
 299 #ifdef ENABLE_GSS
 300 /*----------------------------------------------------------------
 301  * GSSAPI authentication system
 302  *----------------------------------------------------------------
 303  */
 304
 305 #if defined(HAVE_GSSAPI_H)
 306 #include <gssapi.h>
 307 #else
 308 #include <gssapi/gssapi.h>
 309 #endif
 310
 311 #if defined(WIN32) && !defined(WIN32_ONLY_COMPILER)
 312 /*
 313  * MIT Kerberos GSSAPI DLL doesn't properly export the symbols for MingW
 314  * that contain the OIDs required. Redefine here, values copied
 315  * from src/athena/auth/krb5/src/lib/gssapi/generic/gssapi_generic.c
 316  */
 317 static const gss_OID_desc GSS_C_NT_USER_NAME_desc =
 318  {10, (void *)"\x2a\x86\x48\x86\xf7\x12\x01\x02\x01\x02"};
 319 static GSS_DLLIMP gss_OID GSS_C_NT_USER_NAME = &GSS_C_NT_USER_NAME_desc;
 320 #endif
 321
 322
 323 static void
 324 pg_GSS_error(int severity, char *errmsg, OM_uint32 maj_stat, OM_uint32 min_stat)
 325 {
 326         gss_buffer_desc gmsg;
 327         OM_uint32               lmaj_s, lmin_s, msg_ctx;
 328         char                    msg_major[128],
 329                                         msg_minor[128];
 330
 331         /* Fetch major status message */
 332         msg_ctx = 0;
 333         lmaj_s = gss_display_status(&lmin_s, maj_stat, GSS_C_GSS_CODE,
 334                         GSS_C_NO_OID, &msg_ctx, &gmsg);
 335         strlcpy(msg_major, gmsg.value, sizeof(msg_major));
 336         gss_release_buffer(&lmin_s, &gmsg);
 337
 338         if (msg_ctx)
 339                 /* More than one message available.
 340                  * XXX: Should we loop and read all messages?
 341                  * (same below)
 342                  */
 343                 ereport(WARNING,
 344                                 (errmsg_internal("incomplete GSS error report")));
 345
 346         /* Fetch mechanism minor status message */
 347         msg_ctx = 0;
 348         lmaj_s = gss_display_status(&lmin_s, min_stat, GSS_C_MECH_CODE,
 349                         GSS_C_NO_OID, &msg_ctx, &gmsg);
 350         strlcpy(msg_minor, gmsg.value, sizeof(msg_minor));
 351         gss_release_buffer(&lmin_s, &gmsg);
 352
 353         if (msg_ctx)
 354                 ereport(WARNING,
 355                                 (errmsg_internal("incomplete GSS minor error report")));
 356
 357         /* errmsg_internal, since translation of the first part must be
 358          * done before calling this function anyway. */
 359         ereport(severity,
 360                         (errmsg_internal("%s", errmsg),
 361                          errdetail("%s: %s", msg_major, msg_minor)));
 362 }
 363
 364 static int
 365 pg_GSS_recvauth(Port *port)
 366 {
 367         OM_uint32               maj_stat, min_stat, lmin_s, gflags;
 368         char               *kt_path;
 369         int                             mtype;
 370         int                             ret;
 371         StringInfoData  buf;
 372         gss_buffer_desc gbuf;
 373
 374         if (pg_krb_server_keyfile && strlen(pg_krb_server_keyfile) > 0)
 375         {
 376                 /*
 377                  * Set default Kerberos keytab file for the Krb5 mechanism.
 378                  *
 379                  * setenv("KRB5_KTNAME", pg_krb_server_keyfile, 0);
 380                  *              except setenv() not always available.
 381                  */
 382                 if (!getenv("KRB5_KTNAME"))
 383                 {
 384                         kt_path = palloc(MAXPGPATH + 13);
 385                         snprintf(kt_path, MAXPGPATH + 13,
 386                                         "KRB5_KTNAME=%s", pg_krb_server_keyfile);
 387                         putenv(kt_path);
 388                 }
 389         }
 390
 391         /*
 392          * We accept any service principal that's present in our
 393          * keytab. This increases interoperability between kerberos
 394          * implementations that see for example case sensitivity
 395          * differently, while not really opening up any vector
 396          * of attack.
 397          */
 398         port->gss->cred = GSS_C_NO_CREDENTIAL;
 399
 400         /*
 401          * Initialize sequence with an empty context
 402          */
 403         port->gss->ctx = GSS_C_NO_CONTEXT;
 404
 405         /*
 406          * Loop through GSSAPI message exchange. This exchange can consist
 407          * of multiple messags sent in both directions. First message is always
 408          * from the client. All messages from client to server are password
 409          * packets (type 'p').
 410          */
 411         do
 412         {
 413                 mtype = pq_getbyte();
 414                 if (mtype != 'p')
 415                 {
 416                         /* Only log error if client didn't disconnect. */
 417                         if (mtype != EOF)
 418                                 ereport(COMMERROR,
 419                                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
 420                                                  errmsg("expected GSS response, got message type %d",
 421                                                          mtype)));
 422                         return STATUS_ERROR;
 423                 }
 424
 425                 /* Get the actual GSS token */
 426                 initStringInfo(&buf);
 427                 if (pq_getmessage(&buf, 2000))
 428                 {
 429                         /* EOF - pq_getmessage already logged error */
 430                         pfree(buf.data);
 431                         return STATUS_ERROR;
 432                 }
 433
 434                 /* Map to GSSAPI style buffer */
 435                 gbuf.length = buf.len;
 436                 gbuf.value = buf.data;
 437
 438                 elog(DEBUG4, "Processing received GSS token of length %u",
 439                          (unsigned int) gbuf.length);
 440
 441                 maj_stat = gss_accept_sec_context(
 442                                 &min_stat,
 443                                 &port->gss->ctx,
 444                                 port->gss->cred,
 445                                 &gbuf,
 446                                 GSS_C_NO_CHANNEL_BINDINGS,
 447                                 &port->gss->name,
 448                                 NULL,
 449                                 &port->gss->outbuf,
 450                                 &gflags,
 451                                 NULL,
 452                                 NULL);
 453
 454                 /* gbuf no longer used */
 455                 pfree(buf.data);
 456
 457                 elog(DEBUG5, "gss_accept_sec_context major: %d, "
 458                          "minor: %d, outlen: %u, outflags: %x",
 459                          maj_stat, min_stat,
 460                          (unsigned int) port->gss->outbuf.length, gflags);
 461
 462                 if (port->gss->outbuf.length != 0)
 463                 {
 464                         /*
 465                          * Negotiation generated data to be sent to the client.
 466                          */
 467                         OM_uint32       lmin_s;
 468
 469                         elog(DEBUG4, "sending GSS response token of length %u",
 470                                  (unsigned int) port->gss->outbuf.length);
 471
 472                         sendAuthRequest(port, AUTH_REQ_GSS_CONT);
 473
 474                         gss_release_buffer(&lmin_s, &port->gss->outbuf);
 475                 }
 476
 477                 if (maj_stat != GSS_S_COMPLETE && maj_stat != GSS_S_CONTINUE_NEEDED)
 478                 {
 479                         OM_uint32       lmin_s;
 480                         gss_delete_sec_context(&lmin_s, &port->gss->ctx, GSS_C_NO_BUFFER);
 481                         pg_GSS_error(ERROR,
 482                                         gettext_noop("accepting GSS security context failed"),
 483                                         maj_stat, min_stat);
 484                 }
 485
 486                 if (maj_stat == GSS_S_CONTINUE_NEEDED)
 487                         elog(DEBUG4, "GSS continue needed");
 488
 489         } while (maj_stat == GSS_S_CONTINUE_NEEDED);
 490
 491         if (port->gss->cred != GSS_C_NO_CREDENTIAL)
 492         {
 493                 /*
 494                  * Release service principal credentials
 495                  */
 496                 gss_release_cred(&min_stat, port->gss->cred);
 497         }
 498
 499         /*
 500          * GSS_S_COMPLETE indicates that authentication is now complete.
 501          *
 502          * Get the name of the user that authenticated, and compare it to the
 503          * pg username that was specified for the connection.
 504          */
 505         maj_stat = gss_display_name(&min_stat, port->gss->name, &gbuf, NULL);
 506         if (maj_stat != GSS_S_COMPLETE)
 507                 pg_GSS_error(ERROR,
 508                                          gettext_noop("retreiving GSS user name failed"),
 509                                          maj_stat, min_stat);
 510
 511         /*
 512          * Compare the part of the username that comes before the @
 513          * sign only (ignore realm). The GSSAPI libraries won't have
 514          * authenticated the user if he's from an invalid realm.
 515          */
 516         if (strchr(gbuf.value, '@'))
 517         {
 518                 char *cp = strchr(gbuf.value, '@');
 519                 *cp = '\0';
 520         }
 521
 522         if (pg_krb_caseins_users)
 523                 ret = pg_strcasecmp(port->user_name, gbuf.value);
 524         else
 525                 ret = strcmp(port->user_name, gbuf.value);
 526
 527         if (ret)
 528         {
 529                 /* GSS name and PGUSER are not equivalent */
 530                 elog(DEBUG2,
 531                          "provided username (%s) and GSSAPI username (%s) don't match",
 532                          port->user_name, (char *)gbuf.value);
 533
 534                 gss_release_buffer(&lmin_s, &gbuf);
 535                 return STATUS_ERROR;
 536         }
 537
 538         gss_release_buffer(&lmin_s, &gbuf);
 539
 540         return STATUS_OK;
 541 }
 542
 543 #else /* no ENABLE_GSS */
 544 static int
 545 pg_GSS_recvauth(Port *port)
 546 {
 547         ereport(LOG,
 548                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 549                          errmsg("GSSAPI not implemented on this server.")));
 550         return STATUS_ERROR;
 551 }
 552 #endif  /* ENABLE_GSS */
 553
 554 #ifdef ENABLE_SSPI
 555 static void
 556 pg_SSPI_error(int severity, char *errmsg, SECURITY_STATUS r)
 557 {
 558         char sysmsg[256];
 559
 560         if (FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, r, 0, sysmsg, sizeof(sysmsg), NULL) == 0)
 561                 ereport(severity,
 562                         (errmsg_internal("%s", errmsg),
 563                                 errdetail("sspi error %x", (unsigned int)r)));
 564         else
 565                 ereport(severity,
 566                         (errmsg_internal("%s", errmsg),
 567                                 errdetail("%s (%x)", sysmsg, (unsigned int)r)));
 568 }
 569
 570 typedef SECURITY_STATUS
 571 (WINAPI * QUERY_SECURITY_CONTEXT_TOKEN_FN)(
 572     PCtxtHandle, void **);
 573
 574 static int
 575 pg_SSPI_recvauth(Port *port)
 576 {
 577         int                             mtype;
 578         StringInfoData  buf;
 579         SECURITY_STATUS r;
 580         CredHandle              sspicred;
 581         CtxtHandle              *sspictx = NULL,
 582                             newctx;
 583         TimeStamp               expiry;
 584         ULONG                   contextattr;
 585         SecBufferDesc   inbuf;
 586         SecBufferDesc   outbuf;
 587         SecBuffer               OutBuffers[1];
 588         SecBuffer               InBuffers[1];
 589         HANDLE                  token;
 590         TOKEN_USER              *tokenuser;
 591         DWORD                   retlen;
 592         char                    accountname[MAXPGPATH];
 593         char                    domainname[MAXPGPATH];
 594         DWORD                   accountnamesize = sizeof(accountname);
 595         DWORD                   domainnamesize = sizeof(domainname);
 596         SID_NAME_USE    accountnameuse;
 597         HMODULE                 secur32;
 598         QUERY_SECURITY_CONTEXT_TOKEN_FN _QuerySecurityContextToken;
 599
 600
 601         /*
 602          * Acquire a handle to the server credentials.
 603          */
 604         r = AcquireCredentialsHandle(NULL,
 605                 "negotiate",
 606                 SECPKG_CRED_INBOUND,
 607                 NULL,
 608                 NULL,
 609                 NULL,
 610                 NULL,
 611                 &sspicred,
 612                 &expiry);
 613         if (r != SEC_E_OK)
 614                 pg_SSPI_error(ERROR,
 615                                         gettext_noop("could not acquire SSPI credentials handle"), r);
 616
 617         /*
 618          * Loop through SSPI message exchange. This exchange can consist
 619          * of multiple messags sent in both directions. First message is always
 620          * from the client. All messages from client to server are password
 621          * packets (type 'p').
 622          */
 623         do
 624         {
 625                 mtype = pq_getbyte();
 626                 if (mtype != 'p')
 627                 {
 628                         /* Only log error if client didn't disconnect. */
 629                         if (mtype != EOF)
 630                                 ereport(COMMERROR,
 631                                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
 632                                                  errmsg("expected SSPI response, got message type %d",
 633                                                          mtype)));
 634                         return STATUS_ERROR;
 635                 }
 636
 637                 /* Get the actual SSPI token */
 638                 initStringInfo(&buf);
 639                 if (pq_getmessage(&buf, 2000))
 640                 {
 641                         /* EOF - pq_getmessage already logged error */
 642                         pfree(buf.data);
 643                         return STATUS_ERROR;
 644                 }
 645
 646                 /* Map to SSPI style buffer */
 647                 inbuf.ulVersion = SECBUFFER_VERSION;
 648                 inbuf.cBuffers = 1;
 649                 inbuf.pBuffers = InBuffers;
 650                 InBuffers[0].pvBuffer = buf.data;
 651                 InBuffers[0].cbBuffer = buf.len;
 652                 InBuffers[0].BufferType = SECBUFFER_TOKEN;
 653
 654                 /* Prepare output buffer */
 655                 OutBuffers[0].pvBuffer = NULL;
 656                 OutBuffers[0].BufferType = SECBUFFER_TOKEN;
 657                 OutBuffers[0].cbBuffer = 0;
 658                 outbuf.cBuffers = 1;
 659                 outbuf.pBuffers = OutBuffers;
 660                 outbuf.ulVersion = SECBUFFER_VERSION;
 661
 662
 663                 elog(DEBUG4, "Processing received SSPI token of length %u",
 664                          (unsigned int) buf.len);
 665
 666                 r = AcceptSecurityContext(&sspicred,
 667                         sspictx,
 668                         &inbuf,
 669                         ASC_REQ_ALLOCATE_MEMORY,
 670                         SECURITY_NETWORK_DREP,
 671                         &newctx,
 672                         &outbuf,
 673                         &contextattr,
 674                         NULL);
 675
 676                 /* input buffer no longer used */
 677                 pfree(buf.data);
 678
 679                 if (outbuf.cBuffers > 0 && outbuf.pBuffers[0].cbBuffer > 0)
 680                 {
 681                         /*
 682                          * Negotiation generated data to be sent to the client.
 683                          */
 684                         elog(DEBUG4, "sending SSPI response token of length %u",
 685                                  (unsigned int) outbuf.pBuffers[0].cbBuffer);
 686
 687                         port->gss->outbuf.length = outbuf.pBuffers[0].cbBuffer;
 688                         port->gss->outbuf.value = outbuf.pBuffers[0].pvBuffer;
 689
 690                         sendAuthRequest(port, AUTH_REQ_GSS_CONT);
 691
 692                         FreeContextBuffer(outbuf.pBuffers[0].pvBuffer);
 693                 }
 694
 695                 if (r != SEC_E_OK && r != SEC_I_CONTINUE_NEEDED)
 696                 {
 697                         if (sspictx != NULL)
 698                         {
 699                                 DeleteSecurityContext(sspictx);
 700                                 free(sspictx);
 701                         }
 702                         FreeCredentialsHandle(&sspicred);
 703                         pg_SSPI_error(ERROR,
 704                                         gettext_noop("could not accept SSPI security context"), r);
 705                 }
 706
 707                 if (sspictx == NULL)
 708                 {
 709                         sspictx = malloc(sizeof(CtxtHandle));
 710                         if (sspictx == NULL)
 711                                 ereport(ERROR,
 712                                         (errmsg("out of memory")));
 713
 714                         memcpy(sspictx, &newctx, sizeof(CtxtHandle));
 715                 }
 716
 717                 if (r == SEC_I_CONTINUE_NEEDED)
 718                         elog(DEBUG4, "SSPI continue needed");
 719
 720         } while (r == SEC_I_CONTINUE_NEEDED);
 721
 722
 723         /*
 724          * Release service principal credentials
 725          */
 726         FreeCredentialsHandle(&sspicred);
 727
 728
 729         /*
 730          * SEC_E_OK indicates that authentication is now complete.
 731          *
 732          * Get the name of the user that authenticated, and compare it to the
 733          * pg username that was specified for the connection.
 734          *
 735          * MingW is missing the export for QuerySecurityContextToken in
 736          * the secur32 library, so we have to load it dynamically.
 737          */
 738
 739         secur32 = LoadLibrary("SECUR32.DLL");
 740         if (secur32 == NULL)
 741                 ereport(ERROR,
 742                         (errmsg_internal("could not load secur32.dll: %d",
 743                         (int)GetLastError())));
 744
 745         _QuerySecurityContextToken = (QUERY_SECURITY_CONTEXT_TOKEN_FN)
 746                 GetProcAddress(secur32, "QuerySecurityContextToken");
 747         if (_QuerySecurityContextToken == NULL)
 748         {
 749                 FreeLibrary(secur32);
 750                 ereport(ERROR,
 751                         (errmsg_internal("could not locate QuerySecurityContextToken in secur32.dll: %d",
 752                         (int)GetLastError())));
 753         }
 754
 755         r = (_QuerySecurityContextToken)(sspictx, &token);
 756         if (r != SEC_E_OK)
 757         {
 758                 FreeLibrary(secur32);
 759                 pg_SSPI_error(ERROR,
 760                         gettext_noop("could not get security token from context"), r);
 761         }
 762
 763         FreeLibrary(secur32);
 764
 765         /*
 766          * No longer need the security context, everything from here on uses the
 767          * token instead.
 768          */
 769         DeleteSecurityContext(sspictx);
 770         free(sspictx);
 771
 772         if (!GetTokenInformation(token, TokenUser, NULL, 0, &retlen) && GetLastError() != 122)
 773                 ereport(ERROR,
 774                                 (errmsg_internal("could not get token user size: error code %d",
 775                                         (int) GetLastError())));
 776
 777         tokenuser = malloc(retlen);
 778         if (tokenuser == NULL)
 779                 ereport(ERROR,
 780                                 (errmsg("out of memory")));
 781
 782         if (!GetTokenInformation(token, TokenUser, tokenuser, retlen, &retlen))
 783                 ereport(ERROR,
 784                                 (errmsg_internal("could not get user token: error code %d",
 785                                         (int) GetLastError())));
 786
 787         if (!LookupAccountSid(NULL, tokenuser->User.Sid, accountname, &accountnamesize,
 788                                                         domainname, &domainnamesize, &accountnameuse))
 789                 ereport(ERROR,
 790                                 (errmsg_internal("could not lookup acconut sid: error code %d",
 791                                         (int) GetLastError())));
 792
 793         free(tokenuser);
 794
 795         /*
 796          * We have the username (without domain/realm) in accountname, compare
 797          * to the supplied value. In SSPI, always compare case insensitive.
 798          */
 799         if (pg_strcasecmp(port->user_name, accountname))
 800         {
 801                 /* GSS name and PGUSER are not equivalent */
 802                 elog(DEBUG2,
 803                          "provided username (%s) and SSPI username (%s) don't match",
 804                          port->user_name, accountname);
 805
 806                 return STATUS_ERROR;
 807         }
 808
 809         return STATUS_OK;
 810 }
 811 #else   /* no ENABLE_SSPI */
 812 static int
 813 pg_SSPI_recvauth(Port *port)
 814 {
 815         ereport(LOG,
 816                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 817                          errmsg("SSPI not implemented on this server.")));
 818         return STATUS_ERROR;
 819 }
 820 #endif  /* ENABLE_SSPI */
 821
 822
 823 /*
 824  * Tell the user the authentication failed, but not (much about) why.
 825  *
 826  * There is a tradeoff here between security concerns and making life
 827  * unnecessarily difficult for legitimate users.  We would not, for example,
 828  * want to report the password we were expecting to receive...
 829  * But it seems useful to report the username and authorization method
 830  * in use, and these are items that must be presumed known to an attacker
 831  * anyway.
 832  * Note that many sorts of failure report additional information in the
 833  * postmaster log, which we hope is only readable by good guys.
 834  */
 835 static void
 836 auth_failed(Port *port, int status)
 837 {
 838         const char *errstr;
 839
 840         /*
 841          * If we failed due to EOF from client, just quit; there's no point in
 842          * trying to send a message to the client, and not much point in logging
 843          * the failure in the postmaster log.  (Logging the failure might be
 844          * desirable, were it not for the fact that libpq closes the connection
 845          * unceremoniously if challenged for a password when it hasn't got one to
 846          * send.  We'll get a useless log entry for every psql connection under
 847          * password auth, even if it's perfectly successful, if we log STATUS_EOF
 848          * events.)
 849          */
 850         if (status == STATUS_EOF)
 851                 proc_exit(0);
 852
 853         switch (port->auth_method)
 854         {
 855                 case uaReject:
 856                         errstr = gettext_noop("authentication failed for user \"%s\": host rejected");
 857                         break;
 858                 case uaKrb5:
 859                         errstr = gettext_noop("Kerberos 5 authentication failed for user \"%s\"");
 860                         break;
 861                 case uaGSS:
 862                         errstr = gettext_noop("GSSAPI authentication failed for user \"%s\"");
 863                         break;
 864                 case uaSSPI:
 865                         errstr = gettext_noop("SSPI authentication failed for user \"%s\"");
 866                         break;
 867                 case uaTrust:
 868                         errstr = gettext_noop("\"trust\" authentication failed for user \"%s\"");
 869                         break;
 870                 case uaIdent:
 871                         errstr = gettext_noop("Ident authentication failed for user \"%s\"");
 872                         break;
 873                 case uaMD5:
 874                 case uaCrypt:
 875                 case uaPassword:
 876                         errstr = gettext_noop("password authentication failed for user \"%s\"");
 877                         break;
 878 #ifdef USE_PAM
 879                 case uaPAM:
 880                         errstr = gettext_noop("PAM authentication failed for user \"%s\"");
 881                         break;
 882 #endif   /* USE_PAM */
 883 #ifdef USE_LDAP
 884                 case uaLDAP:
 885                         errstr = gettext_noop("LDAP authentication failed for user \"%s\"");
 886                         break;
 887 #endif   /* USE_LDAP */
 888                 default:
 889                         errstr = gettext_noop("authentication failed for user \"%s\": invalid authentication method");
 890                         break;
 891         }
 892
 893         ereport(FATAL,
 894                         (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
 895                          errmsg(errstr, port->user_name)));
 896         /* doesn't return */
 897 }
 898
 899
 900 /*
 901  * Client authentication starts here.  If there is an error, this
 902  * function does not return and the backend process is terminated.
 903  */
 904 void
 905 ClientAuthentication(Port *port)
 906 {
 907         int                     status = STATUS_ERROR;
 908
 909         /*
 910          * Get the authentication method to use for this frontend/database
 911          * combination.  Note: a failure return indicates a problem with the hba
 912          * config file, not with the request.  hba.c should have dropped an error
 913          * message into the postmaster logfile if it failed.
 914          */
 915         if (hba_getauthmethod(port) != STATUS_OK)
 916                 ereport(FATAL,
 917                                 (errcode(ERRCODE_CONFIG_FILE_ERROR),
 918                                  errmsg("missing or erroneous pg_hba.conf file"),
 919                                  errhint("See server log for details.")));
 920
 921         switch (port->auth_method)
 922         {
 923                 case uaReject:
 924
 925                         /*
 926                          * This could have come from an explicit "reject" entry in
 927                          * pg_hba.conf, but more likely it means there was no matching
 928                          * entry.  Take pity on the poor user and issue a helpful error
 929                          * message.  NOTE: this is not a security breach, because all the
 930                          * info reported here is known at the frontend and must be assumed
 931                          * known to bad guys. We're merely helping out the less clueful
 932                          * good guys.
 933                          */
 934                         {
 935                                 char            hostinfo[NI_MAXHOST];
 936
 937                                 pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
 938                                                                    hostinfo, sizeof(hostinfo),
 939                                                                    NULL, 0,
 940                                                                    NI_NUMERICHOST);
 941
 942 #ifdef USE_SSL
 943                                 ereport(FATAL,
 944                                                 (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
 945                                                  errmsg("no pg_hba.conf entry for host \"%s\", user \"%s\", database \"%s\", %s",
 946                                                           hostinfo, port->user_name, port->database_name,
 947                                                                 port->ssl ? _("SSL on") : _("SSL off"))));
 948 #else
 949                                 ereport(FATAL,
 950                                                 (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
 951                                                  errmsg("no pg_hba.conf entry for host \"%s\", user \"%s\", database \"%s\"",
 952                                                    hostinfo, port->user_name, port->database_name)));
 953 #endif
 954                                 break;
 955                         }
 956
 957                 case uaKrb5:
 958                         sendAuthRequest(port, AUTH_REQ_KRB5);
 959                         status = pg_krb5_recvauth(port);
 960                         break;
 961
 962                 case uaGSS:
 963                         sendAuthRequest(port, AUTH_REQ_GSS);
 964                         status = pg_GSS_recvauth(port);
 965                         break;
 966
 967                 case uaSSPI:
 968                         sendAuthRequest(port, AUTH_REQ_SSPI);
 969                         status = pg_SSPI_recvauth(port);
 970                         break;
 971
 972                 case uaIdent:
 973
 974                         /*
 975                          * If we are doing ident on unix-domain sockets, use SCM_CREDS
 976                          * only if it is defined and SO_PEERCRED isn't.
 977                          */
 978 #if !defined(HAVE_GETPEEREID) && !defined(SO_PEERCRED) && \
 979         (defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || \
 980          (defined(HAVE_STRUCT_SOCKCRED) && defined(LOCAL_CREDS)))
 981                         if (port->raddr.addr.ss_family == AF_UNIX)
 982                         {
 983 #if defined(HAVE_STRUCT_FCRED) || defined(HAVE_STRUCT_SOCKCRED)
 984
 985                                 /*
 986                                  * Receive credentials on next message receipt, BSD/OS,
 987                                  * NetBSD. We need to set this before the client sends the
 988                                  * next packet.
 989                                  */
 990                                 int                     on = 1;
 991
 992                                 if (setsockopt(port->sock, 0, LOCAL_CREDS, &on, sizeof(on)) < 0)
 993                                         ereport(FATAL,
 994                                                         (errcode_for_socket_access(),
 995                                            errmsg("could not enable credential reception: %m")));
 996 #endif
 997
 998                                 sendAuthRequest(port, AUTH_REQ_SCM_CREDS);
 999                         }
1000 #endif
1001                         status = authident(port);
1002                         break;
1003
1004                 case uaMD5:
1005                         sendAuthRequest(port, AUTH_REQ_MD5);
1006                         status = recv_and_check_password_packet(port);
1007                         break;
1008
1009                 case uaCrypt:
1010                         sendAuthRequest(port, AUTH_REQ_CRYPT);
1011                         status = recv_and_check_password_packet(port);
1012                         break;
1013
1014                 case uaPassword:
1015                         sendAuthRequest(port, AUTH_REQ_PASSWORD);
1016                         status = recv_and_check_password_packet(port);
1017                         break;
1018
1019 #ifdef USE_PAM
1020                 case uaPAM:
1021                         pam_port_cludge = port;
1022                         status = CheckPAMAuth(port, port->user_name, "");
1023                         break;
1024 #endif   /* USE_PAM */
1025
1026 #ifdef USE_LDAP
1027                 case uaLDAP:
1028                         status = CheckLDAPAuth(port);
1029                         break;
1030 #endif
1031
1032                 case uaTrust:
1033                         status = STATUS_OK;
1034                         break;
1035         }
1036
1037         if (status == STATUS_OK)
1038                 sendAuthRequest(port, AUTH_REQ_OK);
1039         else
1040                 auth_failed(port, status);
1041 }
1042
1043
1044 /*
1045  * Send an authentication request packet to the frontend.
1046  */
1047 static void
1048 sendAuthRequest(Port *port, AuthRequest areq)
1049 {
1050         StringInfoData buf;
1051
1052         pq_beginmessage(&buf, 'R');
1053         pq_sendint(&buf, (int32) areq, sizeof(int32));
1054
1055         /* Add the salt for encrypted passwords. */
1056         if (areq == AUTH_REQ_MD5)
1057                 pq_sendbytes(&buf, port->md5Salt, 4);
1058         else if (areq == AUTH_REQ_CRYPT)
1059                 pq_sendbytes(&buf, port->cryptSalt, 2);
1060
1061 #if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
1062         /* Add the authentication data for the next step of
1063          * the GSSAPI or SSPI negotiation. */
1064         else if (areq == AUTH_REQ_GSS_CONT)
1065         {
1066                 if (port->gss->outbuf.length > 0)
1067                 {
1068                         elog(DEBUG4, "sending GSS token of length %u",
1069                                  (unsigned int) port->gss->outbuf.length);
1070
1071                         pq_sendbytes(&buf, port->gss->outbuf.value, port->gss->outbuf.length);
1072                 }
1073         }
1074 #endif
1075
1076         pq_endmessage(&buf);
1077
1078         /*
1079          * Flush message so client will see it, except for AUTH_REQ_OK, which need
1080          * not be sent until we are ready for queries.
1081          */
1082         if (areq != AUTH_REQ_OK)
1083                 pq_flush();
1084 }
1085
1086
1087 #ifdef USE_PAM
1088
1089 /*
1090  * PAM conversation function
1091  */
1092
1093 static int
1094 pam_passwd_conv_proc(int num_msg, const struct pam_message ** msg,
1095                                          struct pam_response ** resp, void *appdata_ptr)
1096 {
1097         if (num_msg != 1 || msg[0]->msg_style != PAM_PROMPT_ECHO_OFF)
1098         {
1099                 switch (msg[0]->msg_style)
1100                 {
1101                         case PAM_ERROR_MSG:
1102                                 ereport(LOG,
1103                                                 (errmsg("error from underlying PAM layer: %s",
1104                                                                 msg[0]->msg)));
1105                                 return PAM_CONV_ERR;
1106                         default:
1107                                 ereport(LOG,
1108                                                 (errmsg("unsupported PAM conversation %d/%s",
1109                                                                 msg[0]->msg_style, msg[0]->msg)));
1110                                 return PAM_CONV_ERR;
1111                 }
1112         }
1113
1114         if (!appdata_ptr)
1115         {
1116                 /*
1117                  * Workaround for Solaris 2.6 where the PAM library is broken and does
1118                  * not pass appdata_ptr to the conversation routine
1119                  */
1120                 appdata_ptr = pam_passwd;
1121         }
1122
1123         /*
1124          * Password wasn't passed to PAM the first time around - let's go ask the
1125          * client to send a password, which we then stuff into PAM.
1126          */
1127         if (strlen(appdata_ptr) == 0)
1128         {
1129                 char       *passwd;
1130
1131                 sendAuthRequest(pam_port_cludge, AUTH_REQ_PASSWORD);
1132                 passwd = recv_password_packet(pam_port_cludge);
1133
1134                 if (passwd == NULL)
1135                         return PAM_CONV_ERR;    /* client didn't want to send password */
1136
1137                 if (strlen(passwd) == 0)
1138                 {
1139                         ereport(LOG,
1140                                         (errmsg("empty password returned by client")));
1141                         return PAM_CONV_ERR;
1142                 }
1143                 appdata_ptr = passwd;
1144         }
1145
1146         /*
1147          * Explicitly not using palloc here - PAM will free this memory in
1148          * pam_end()
1149          */
1150         *resp = calloc(num_msg, sizeof(struct pam_response));
1151         if (!*resp)
1152         {
1153                 ereport(LOG,
1154                                 (errcode(ERRCODE_OUT_OF_MEMORY),
1155                                  errmsg("out of memory")));
1156                 return PAM_CONV_ERR;
1157         }
1158
1159         (*resp)[0].resp = strdup((char *) appdata_ptr);
1160         (*resp)[0].resp_retcode = 0;
1161
1162         return ((*resp)[0].resp ? PAM_SUCCESS : PAM_CONV_ERR);
1163 }
1164
1165
1166 /*
1167  * Check authentication against PAM.
1168  */
1169 static int
1170 CheckPAMAuth(Port *port, char *user, char *password)
1171 {
1172         int                     retval;
1173         pam_handle_t *pamh = NULL;
1174
1175         /*
1176          * Apparently, Solaris 2.6 is broken, and needs ugly static variable
1177          * workaround
1178          */
1179         pam_passwd = password;
1180
1181         /*
1182          * Set the application data portion of the conversation struct This is
1183          * later used inside the PAM conversation to pass the password to the
1184          * authentication module.
1185          */
1186         pam_passw_conv.appdata_ptr = (char *) password;         /* from password above,
1187                                                                                                                  * not allocated */
1188
1189         /* Optionally, one can set the service name in pg_hba.conf */
1190         if (port->auth_arg && port->auth_arg[0] != '\0')
1191                 retval = pam_start(port->auth_arg, "pgsql@",
1192                                                    &pam_passw_conv, &pamh);
1193         else
1194                 retval = pam_start(PGSQL_PAM_SERVICE, "pgsql@",
1195                                                    &pam_passw_conv, &pamh);
1196
1197         if (retval != PAM_SUCCESS)
1198         {
1199                 ereport(LOG,
1200                                 (errmsg("could not create PAM authenticator: %s",
1201                                                 pam_strerror(pamh, retval))));
1202                 pam_passwd = NULL;              /* Unset pam_passwd */
1203                 return STATUS_ERROR;
1204         }
1205
1206         retval = pam_set_item(pamh, PAM_USER, user);
1207
1208         if (retval != PAM_SUCCESS)
1209         {
1210                 ereport(LOG,
1211                                 (errmsg("pam_set_item(PAM_USER) failed: %s",
1212                                                 pam_strerror(pamh, retval))));
1213                 pam_passwd = NULL;              /* Unset pam_passwd */
1214                 return STATUS_ERROR;
1215         }
1216
1217         retval = pam_set_item(pamh, PAM_CONV, &pam_passw_conv);
1218
1219         if (retval != PAM_SUCCESS)
1220         {
1221                 ereport(LOG,
1222                                 (errmsg("pam_set_item(PAM_CONV) failed: %s",
1223                                                 pam_strerror(pamh, retval))));
1224                 pam_passwd = NULL;              /* Unset pam_passwd */
1225                 return STATUS_ERROR;
1226         }
1227
1228         retval = pam_authenticate(pamh, 0);
1229
1230         if (retval != PAM_SUCCESS)
1231         {
1232                 ereport(LOG,
1233                                 (errmsg("pam_authenticate failed: %s",
1234                                                 pam_strerror(pamh, retval))));
1235                 pam_passwd = NULL;              /* Unset pam_passwd */
1236                 return STATUS_ERROR;
1237         }
1238
1239         retval = pam_acct_mgmt(pamh, 0);
1240
1241         if (retval != PAM_SUCCESS)
1242         {
1243                 ereport(LOG,
1244                                 (errmsg("pam_acct_mgmt failed: %s",
1245                                                 pam_strerror(pamh, retval))));
1246                 pam_passwd = NULL;              /* Unset pam_passwd */
1247                 return STATUS_ERROR;
1248         }
1249
1250         retval = pam_end(pamh, retval);
1251
1252         if (retval != PAM_SUCCESS)
1253         {
1254                 ereport(LOG,
1255                                 (errmsg("could not release PAM authenticator: %s",
1256                                                 pam_strerror(pamh, retval))));
1257         }
1258
1259         pam_passwd = NULL;                      /* Unset pam_passwd */
1260
1261         return (retval == PAM_SUCCESS ? STATUS_OK : STATUS_ERROR);
1262 }
1263 #endif   /* USE_PAM */
1264
1265
1266 #ifdef USE_LDAP
1267
1268 static int
1269 CheckLDAPAuth(Port *port)
1270 {
1271         char       *passwd;
1272         char            server[128];
1273         char            basedn[128];
1274         char            prefix[128];
1275         char            suffix[128];
1276         LDAP       *ldap;
1277         bool            ssl = false;
1278         int                     r;
1279         int                     ldapversion = LDAP_VERSION3;
1280         int                     ldapport = LDAP_PORT;
1281         char            fulluser[NAMEDATALEN + 256 + 1];
1282
1283         if (!port->auth_arg || port->auth_arg[0] == '\0')
1284         {
1285                 ereport(LOG,
1286                                 (errmsg("LDAP configuration URL not specified")));
1287                 return STATUS_ERROR;
1288         }
1289
1290         /*
1291          * Crack the LDAP url. We do a very trivial parse..
1292          * ldap[s]://<server>[:<port>]/<basedn>[;prefix[;suffix]]
1293          */
1294
1295         server[0] = '\0';
1296         basedn[0] = '\0';
1297         prefix[0] = '\0';
1298         suffix[0] = '\0';
1299
1300         /* ldap, including port number */
1301         r = sscanf(port->auth_arg,
1302                            "ldap://%127[^:]:%d/%127[^;];%127[^;];%127s",
1303                            server, &ldapport, basedn, prefix, suffix);
1304         if (r < 3)
1305         {
1306                 /* ldaps, including port number */
1307                 r = sscanf(port->auth_arg,
1308                                    "ldaps://%127[^:]:%d/%127[^;];%127[^;];%127s",
1309                                    server, &ldapport, basedn, prefix, suffix);
1310                 if (r >= 3)
1311                         ssl = true;
1312         }
1313         if (r < 3)
1314         {
1315                 /* ldap, no port number */
1316                 r = sscanf(port->auth_arg,
1317                                    "ldap://%127[^/]/%127[^;];%127[^;];%127s",
1318                                    server, basedn, prefix, suffix);
1319         }
1320         if (r < 2)
1321         {
1322                 /* ldaps, no port number */
1323                 r = sscanf(port->auth_arg,
1324                                    "ldaps://%127[^/]/%127[^;];%127[^;];%127s",
1325                                    server, basedn, prefix, suffix);
1326                 if (r >= 2)
1327                         ssl = true;
1328         }
1329         if (r < 2)
1330         {
1331                 ereport(LOG,
1332                                 (errmsg("invalid LDAP URL: \"%s\"",
1333                                                 port->auth_arg)));
1334                 return STATUS_ERROR;
1335         }
1336
1337         sendAuthRequest(port, AUTH_REQ_PASSWORD);
1338
1339         passwd = recv_password_packet(port);
1340         if (passwd == NULL)
1341                 return STATUS_EOF;              /* client wouldn't send password */
1342
1343         ldap = ldap_init(server, ldapport);
1344         if (!ldap)
1345         {
1346 #ifndef WIN32
1347                 ereport(LOG,
1348                                 (errmsg("could not initialize LDAP: error code %d",
1349                                                 errno)));
1350 #else
1351                 ereport(LOG,
1352                                 (errmsg("could not initialize LDAP: error code %d",
1353                                                 (int) LdapGetLastError())));
1354 #endif
1355                 return STATUS_ERROR;
1356         }
1357
1358         if ((r = ldap_set_option(ldap, LDAP_OPT_PROTOCOL_VERSION, &ldapversion)) != LDAP_SUCCESS)
1359         {
1360                 ldap_unbind(ldap);
1361                 ereport(LOG,
1362                                 (errmsg("could not set LDAP protocol version: error code %d", r)));
1363                 return STATUS_ERROR;
1364         }
1365
1366         if (ssl)
1367         {
1368 #ifndef WIN32
1369                 if ((r = ldap_start_tls_s(ldap, NULL, NULL)) != LDAP_SUCCESS)
1370 #else
1371                 static __ldap_start_tls_sA _ldap_start_tls_sA = NULL;
1372
1373                 if (_ldap_start_tls_sA == NULL)
1374                 {
1375                         /*
1376                          * Need to load this function dynamically because it does not
1377                          * exist on Windows 2000, and causes a load error for the whole
1378                          * exe if referenced.
1379                          */
1380                         HANDLE          ldaphandle;
1381
1382                         ldaphandle = LoadLibrary("WLDAP32.DLL");
1383                         if (ldaphandle == NULL)
1384                         {
1385                                 /*
1386                                  * should never happen since we import other files from
1387                                  * wldap32, but check anyway
1388                                  */
1389                                 ldap_unbind(ldap);
1390                                 ereport(LOG,
1391                                                 (errmsg("could not load wldap32.dll")));
1392                                 return STATUS_ERROR;
1393                         }
1394                         _ldap_start_tls_sA = (__ldap_start_tls_sA) GetProcAddress(ldaphandle, "ldap_start_tls_sA");
1395                         if (_ldap_start_tls_sA == NULL)
1396                         {
1397                                 ldap_unbind(ldap);
1398                                 ereport(LOG,
1399                                                 (errmsg("could not load function _ldap_start_tls_sA in wldap32.dll"),
1400                                                  errdetail("LDAP over SSL is not supported on this platform.")));
1401                                 return STATUS_ERROR;
1402                         }
1403
1404                         /*
1405                          * Leak LDAP handle on purpose, because we need the library to stay
1406                          * open. This is ok because it will only ever be leaked once per
1407                          * process and is automatically cleaned up on process exit.
1408                          */
1409                 }
1410                 if ((r = _ldap_start_tls_sA(ldap, NULL, NULL, NULL, NULL)) != LDAP_SUCCESS)
1411 #endif
1412                 {
1413                         ldap_unbind(ldap);
1414                         ereport(LOG,
1415                                         (errmsg("could not start LDAP TLS session: error code %d", r)));
1416                         return STATUS_ERROR;
1417                 }
1418         }
1419
1420         snprintf(fulluser, sizeof(fulluser), "%s%s%s",
1421                          prefix, port->user_name, suffix);
1422         fulluser[sizeof(fulluser) - 1] = '\0';
1423
1424         r = ldap_simple_bind_s(ldap, fulluser, passwd);
1425         ldap_unbind(ldap);
1426
1427         if (r != LDAP_SUCCESS)
1428         {
1429                 ereport(LOG,
1430                                 (errmsg("LDAP login failed for user \"%s\" on server \"%s\": error code %d",
1431                                                 fulluser, server, r)));
1432                 return STATUS_ERROR;
1433         }
1434
1435         return STATUS_OK;
1436 }
1437 #endif   /* USE_LDAP */
1438
1439 /*
1440  * Collect password response packet from frontend.
1441  *
1442  * Returns NULL if couldn't get password, else palloc'd string.
1443  */
1444 static char *
1445 recv_password_packet(Port *port)
1446 {
1447         StringInfoData buf;
1448
1449         if (PG_PROTOCOL_MAJOR(port->proto) >= 3)
1450         {
1451                 /* Expect 'p' message type */
1452                 int                     mtype;
1453
1454                 mtype = pq_getbyte();
1455                 if (mtype != 'p')
1456                 {
1457                         /*
1458                          * If the client just disconnects without offering a password,
1459                          * don't make a log entry.  This is legal per protocol spec and in
1460                          * fact commonly done by psql, so complaining just clutters the
1461                          * log.
1462                          */
1463                         if (mtype != EOF)
1464                                 ereport(COMMERROR,
1465                                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1466                                         errmsg("expected password response, got message type %d",
1467                                                    mtype)));
1468                         return NULL;            /* EOF or bad message type */
1469                 }
1470         }
1471         else
1472         {
1473                 /* For pre-3.0 clients, avoid log entry if they just disconnect */
1474                 if (pq_peekbyte() == EOF)
1475                         return NULL;            /* EOF */
1476         }
1477
1478         initStringInfo(&buf);
1479         if (pq_getmessage(&buf, 1000))          /* receive password */
1480         {
1481                 /* EOF - pq_getmessage already logged a suitable message */
1482                 pfree(buf.data);
1483                 return NULL;
1484         }
1485
1486         /*
1487          * Apply sanity check: password packet length should agree with length of
1488          * contained string.  Note it is safe to use strlen here because
1489          * StringInfo is guaranteed to have an appended '\0'.
1490          */
1491         if (strlen(buf.data) + 1 != buf.len)
1492                 ereport(COMMERROR,
1493                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1494                                  errmsg("invalid password packet size")));
1495
1496         /* Do not echo password to logs, for security. */
1497         ereport(DEBUG5,
1498                         (errmsg("received password packet")));
1499
1500         /*
1501          * Return the received string.  Note we do not attempt to do any
1502          * character-set conversion on it; since we don't yet know the client's
1503          * encoding, there wouldn't be much point.
1504          */
1505         return buf.data;
1506 }
1507
1508
1509 /*
1510  * Called when we have sent an authorization request for a password.
1511  * Get the response and check it.
1512  */
1513 static int
1514 recv_and_check_password_packet(Port *port)
1515 {
1516         char       *passwd;
1517         int                     result;
1518
1519         passwd = recv_password_packet(port);
1520
1521         if (passwd == NULL)
1522                 return STATUS_EOF;              /* client wouldn't send password */
1523
1524         result = md5_crypt_verify(port, port->user_name, passwd);
1525
1526         pfree(passwd);
1527
1528         return result;
1529 }