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

   1 /*-------------------------------------------------------------------------
   2  *
   3  * fe-auth.c
   4  *         The front-end (client) authorization routines
   5  *
   6  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  * NOTE: the error message strings returned by this module must not
  10  * exceed INITIAL_EXPBUFFER_SIZE (currently 256 bytes).
  11  *
  12  * IDENTIFICATION
  13  *        $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-auth.c,v 1.78 2003/05/16 04:58:03 tgl Exp $
  14  *
  15  *-------------------------------------------------------------------------
  16  */
  17
  18 /*
  19  * INTERFACE ROUTINES
  20  *         frontend (client) routines:
  21  *              fe_sendauth                             send authentication information
  22  *              fe_getauthname                  get user's name according to the client side
  23  *                                                              of the authentication system
  24  *              fe_setauthsvc                   set frontend authentication service
  25  *              fe_getauthsvc                   get current frontend authentication service
  26  *
  27  *
  28  *
  29  */
  30
  31 #include "postgres_fe.h"
  32
  33 #ifdef WIN32
  34 #include "win32.h"
  35 #else
  36 #include <unistd.h>
  37 #include <fcntl.h>
  38 #include <errno.h>
  39 #include <sys/types.h>
  40 #include <sys/param.h>                  /* for MAXHOSTNAMELEN on most */
  41 #include <sys/socket.h>
  42 #if defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || defined(HAVE_STRUCT_SOCKCRED)
  43 #include <sys/uio.h>
  44 #include <sys/ucred.h>
  45 #endif
  46 #ifndef  MAXHOSTNAMELEN
  47 #include <netdb.h>                              /* for MAXHOSTNAMELEN on some */
  48 #endif
  49 #include <pwd.h>
  50 #endif
  51
  52 #ifdef HAVE_CRYPT_H
  53 #include <crypt.h>
  54 #endif
  55
  56 #include "libpq-fe.h"
  57 #include "libpq-int.h"
  58 #include "fe-auth.h"
  59 #include "libpq/crypt.h"
  60
  61
  62 /*
  63  * common definitions for generic fe/be routines
  64  */
  65
  66 #define STARTUP_MSG             7               /* Initialise a connection */
  67 #define STARTUP_KRB4_MSG        10      /* krb4 session follows */
  68 #define STARTUP_KRB5_MSG        11      /* krb5 session follows */
  69 #define STARTUP_PASSWORD_MSG    14              /* Password follows */
  70
  71 struct authsvc
  72 {
  73         const char *name;                       /* service nickname (for command line) */
  74         MsgType         msgtype;                /* startup packet header type */
  75         int                     allowed;                /* initially allowed (before command line
  76                                                                  * option parsing)? */
  77 };
  78
  79 /*
  80  * Command-line parsing routines use this structure to map nicknames
  81  * onto service types (and the startup packets to use with them).
  82  *
  83  * Programs receiving an authentication request use this structure to
  84  * decide which authentication service types are currently permitted.
  85  * By default, all authentication systems compiled into the system are
  86  * allowed.  Unauthenticated connections are disallowed unless there
  87  * isn't any authentication system.
  88  */
  89 static const struct authsvc authsvcs[] = {
  90 #ifdef KRB4
  91         {"krb4", STARTUP_KRB4_MSG, 1},
  92         {"kerberos", STARTUP_KRB4_MSG, 1},
  93 #endif   /* KRB4 */
  94 #ifdef KRB5
  95         {"krb5", STARTUP_KRB5_MSG, 1},
  96         {"kerberos", STARTUP_KRB5_MSG, 1},
  97 #endif   /* KRB5 */
  98         {UNAUTHNAME, STARTUP_MSG,
  99 #if defined(KRB4) || defined(KRB5)
 100                 0
 101 #else                                                   /* !(KRB4 || KRB5) */
 102                 1
 103 #endif   /* !(KRB4 || KRB5) */
 104         },
 105         {"password", STARTUP_PASSWORD_MSG, 0}
 106 };
 107
 108 static const int n_authsvcs = sizeof(authsvcs) / sizeof(struct authsvc);
 109
 110 #ifdef KRB4
 111 /*
 112  * MIT Kerberos authentication system - protocol version 4
 113  */
 114
 115 #include "krb.h"
 116
 117 /* for some reason, this is not defined in krb.h ... */
 118 extern char *tkt_string(void);
 119
 120 /*
 121  * pg_krb4_init -- initialization performed before any Kerberos calls are made
 122  *
 123  * For v4, all we need to do is make sure the library routines get the right
 124  * ticket file if we want them to see a special one.  (They will open the file
 125  * themselves.)
 126  */
 127 static void
 128 pg_krb4_init()
 129 {
 130         char       *realm;
 131         static int      init_done = 0;
 132
 133         if (init_done)
 134                 return;
 135         init_done = 1;
 136
 137         /*
 138          * If the user set PGREALM, then we use a ticket file with a special
 139          * name: <usual-ticket-file-name>@<PGREALM-value>
 140          */
 141         if ((realm = getenv("PGREALM")))
 142         {
 143                 char            tktbuf[MAXPGPATH];
 144
 145                 (void) snprintf(tktbuf, sizeof(tktbuf), "%s@%s", tkt_string(), realm);
 146                 krb_set_tkt_string(tktbuf);
 147         }
 148 }
 149
 150 /*
 151  * pg_krb4_authname -- returns a pointer to static space containing whatever
 152  *                                         name the user has authenticated to the system
 153  *
 154  * We obtain this information by digging around in the ticket file.
 155  */
 156 static char *
 157 pg_krb4_authname(char *PQerrormsg)
 158 {
 159         char            instance[INST_SZ + 1];
 160         char            realm[REALM_SZ + 1];
 161         int                     status;
 162         static char name[SNAME_SZ + 1] = "";
 163
 164         if (name[0])
 165                 return name;
 166
 167         pg_krb4_init();
 168
 169         name[SNAME_SZ] = '\0';
 170         status = krb_get_tf_fullname(tkt_string(), name, instance, realm);
 171         if (status != KSUCCESS)
 172         {
 173                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 174                                  "pg_krb4_authname: krb_get_tf_fullname: %s\n",
 175                                  krb_err_txt[status]);
 176                 return (char *) NULL;
 177         }
 178         return name;
 179 }
 180
 181 /*
 182  * pg_krb4_sendauth -- client routine to send authentication information to
 183  *                                         the server
 184  *
 185  * This routine does not do mutual authentication, nor does it return enough
 186  * information to do encrypted connections.  But then, if we want to do
 187  * encrypted connections, we'll have to redesign the whole RPC mechanism
 188  * anyway.
 189  *
 190  * If the user is too lazy to feed us a hostname, we try to come up with
 191  * something other than "localhost" since the hostname is used as an
 192  * instance and instance names in v4 databases are usually actual hostnames
 193  * (canonicalized to omit all domain suffixes).
 194  */
 195 static int
 196 pg_krb4_sendauth(char *PQerrormsg, int sock,
 197                                  struct sockaddr_in * laddr,
 198                                  struct sockaddr_in * raddr,
 199                                  const char *hostname)
 200 {
 201         long            krbopts = 0;    /* one-way authentication */
 202         KTEXT_ST        clttkt;
 203         int                     status;
 204         char            hostbuf[MAXHOSTNAMELEN];
 205         const char *realm = getenv("PGREALM");          /* NULL == current realm */
 206
 207         if (!hostname || !(*hostname))
 208         {
 209                 if (gethostname(hostbuf, MAXHOSTNAMELEN) < 0)
 210                         strcpy(hostbuf, "localhost");
 211                 hostname = hostbuf;
 212         }
 213
 214         pg_krb4_init();
 215
 216         status = krb_sendauth(krbopts,
 217                                                   sock,
 218                                                   &clttkt,
 219                                                   PG_KRB_SRVNAM,
 220                                                   hostname,
 221                                                   realm,
 222                                                   (u_long) 0,
 223                                                   (MSG_DAT *) NULL,
 224                                                   (CREDENTIALS *) NULL,
 225                                                   NULL,
 226                                                   laddr,
 227                                                   raddr,
 228                                                   PG_KRB4_VERSION);
 229         if (status != KSUCCESS)
 230         {
 231                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 232                                  libpq_gettext("Kerberos 4 error: %s\n"),
 233                                  krb_err_txt[status]);
 234                 return STATUS_ERROR;
 235         }
 236         return STATUS_OK;
 237 }
 238 #endif   /* KRB4 */
 239
 240 #ifdef KRB5
 241 /*
 242  * MIT Kerberos authentication system - protocol version 5
 243  */
 244
 245 #include <krb5.h>
 246 #include <com_err.h>
 247
 248 /*
 249  * pg_an_to_ln -- return the local name corresponding to an authentication
 250  *                                name
 251  *
 252  * XXX Assumes that the first aname component is the user name.  This is NOT
 253  *         necessarily so, since an aname can actually be something out of your
 254  *         worst X.400 nightmare, like
 255  *                ORGANIZATION=U. C. Berkeley/NAME=Paul M. Aoki@CS.BERKELEY.EDU
 256  *         Note that the MIT an_to_ln code does the same thing if you don't
 257  *         provide an aname mapping database...it may be a better idea to use
 258  *         krb5_an_to_ln, except that it punts if multiple components are found,
 259  *         and we can't afford to punt.
 260  */
 261 static char *
 262 pg_an_to_ln(char *aname)
 263 {
 264         char       *p;
 265
 266         if ((p = strchr(aname, '/')) || (p = strchr(aname, '@')))
 267                 *p = '\0';
 268         return aname;
 269 }
 270
 271
 272 /*
 273  * Various krb5 state which is not connection specific, and a flag to
 274  * indicate whether we have initialised it yet.
 275  */
 276 static int      pg_krb5_initialised;
 277 static krb5_context pg_krb5_context;
 278 static krb5_ccache pg_krb5_ccache;
 279 static krb5_principal pg_krb5_client;
 280 static char *pg_krb5_name;
 281
 282
 283 static int
 284 pg_krb5_init(char *PQerrormsg)
 285 {
 286         krb5_error_code retval;
 287
 288         if (pg_krb5_initialised)
 289                 return STATUS_OK;
 290
 291         retval = krb5_init_context(&pg_krb5_context);
 292         if (retval)
 293         {
 294                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 295                                  "pg_krb5_init: krb5_init_context: %s\n",
 296                                  error_message(retval));
 297                 return STATUS_ERROR;
 298         }
 299
 300         retval = krb5_cc_default(pg_krb5_context, &pg_krb5_ccache);
 301         if (retval)
 302         {
 303                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 304                                  "pg_krb5_init: krb5_cc_default: %s\n",
 305                                  error_message(retval));
 306                 krb5_free_context(pg_krb5_context);
 307                 return STATUS_ERROR;
 308         }
 309
 310         retval = krb5_cc_get_principal(pg_krb5_context, pg_krb5_ccache,
 311                                                                    &pg_krb5_client);
 312         if (retval)
 313         {
 314                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 315                                  "pg_krb5_init: krb5_cc_get_principal: %s\n",
 316                                  error_message(retval));
 317                 krb5_cc_close(pg_krb5_context, pg_krb5_ccache);
 318                 krb5_free_context(pg_krb5_context);
 319                 return STATUS_ERROR;
 320         }
 321
 322         retval = krb5_unparse_name(pg_krb5_context, pg_krb5_client, &pg_krb5_name);
 323         if (retval)
 324         {
 325                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 326                                  "pg_krb5_init: krb5_unparse_name: %s\n",
 327                                  error_message(retval));
 328                 krb5_free_principal(pg_krb5_context, pg_krb5_client);
 329                 krb5_cc_close(pg_krb5_context, pg_krb5_ccache);
 330                 krb5_free_context(pg_krb5_context);
 331                 return STATUS_ERROR;
 332         }
 333
 334         pg_krb5_name = pg_an_to_ln(pg_krb5_name);
 335
 336         pg_krb5_initialised = 1;
 337         return STATUS_OK;
 338 }
 339
 340
 341 /*
 342  * pg_krb5_authname -- returns a pointer to static space containing whatever
 343  *                                         name the user has authenticated to the system
 344   */
 345 static const char *
 346 pg_krb5_authname(char *PQerrormsg)
 347 {
 348         if (pg_krb5_init(PQerrormsg) != STATUS_OK)
 349                 return NULL;
 350
 351         return pg_krb5_name;
 352 }
 353
 354
 355 /*
 356  * pg_krb5_sendauth -- client routine to send authentication information to
 357  *                                         the server
 358  */
 359 static int
 360 pg_krb5_sendauth(char *PQerrormsg, int sock,
 361                                  struct sockaddr_in * laddr,
 362                                  struct sockaddr_in * raddr,
 363                                  const char *hostname)
 364 {
 365         krb5_error_code retval;
 366         int                     ret;
 367         krb5_principal server;
 368         krb5_auth_context auth_context = NULL;
 369         krb5_error *err_ret = NULL;
 370         int                     flags;
 371
 372         ret = pg_krb5_init(PQerrormsg);
 373         if (ret != STATUS_OK)
 374                 return ret;
 375
 376         retval = krb5_sname_to_principal(pg_krb5_context, hostname, PG_KRB_SRVNAM,
 377                                                                          KRB5_NT_SRV_HST, &server);
 378         if (retval)
 379         {
 380                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 381                                  "pg_krb5_sendauth: krb5_sname_to_principal: %s\n",
 382                                  error_message(retval));
 383                 return STATUS_ERROR;
 384         }
 385
 386         /*
 387          * libpq uses a non-blocking socket. But kerberos needs a blocking
 388          * socket, and we have to block somehow to do mutual authentication
 389          * anyway. So we temporarily make it blocking.
 390          */
 391         flags = fcntl(sock, F_GETFL);
 392         if (flags < 0 || fcntl(sock, F_SETFL, (long) (flags & ~O_NONBLOCK)))
 393         {
 394                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 395                                  libpq_gettext("could not set socket to blocking mode: %s\n"), strerror(errno));
 396                 krb5_free_principal(pg_krb5_context, server);
 397                 return STATUS_ERROR;
 398         }
 399
 400         retval = krb5_sendauth(pg_krb5_context, &auth_context,
 401                                                    (krb5_pointer) & sock, PG_KRB_SRVNAM,
 402                                                    pg_krb5_client, server,
 403                                                    AP_OPTS_MUTUAL_REQUIRED,
 404                                                    NULL, 0,             /* no creds, use ccache instead */
 405                                                    pg_krb5_ccache, &err_ret, NULL, NULL);
 406         if (retval)
 407         {
 408                 if (retval == KRB5_SENDAUTH_REJECTED && err_ret)
 409                 {
 410 #if defined(HAVE_KRB5_ERROR_TEXT_DATA)
 411                         snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 412                           libpq_gettext("Kerberos 5 authentication rejected: %*s\n"),
 413                                          err_ret->text.length, err_ret->text.data);
 414 #elif defined(HAVE_KRB5_ERROR_E_DATA)
 415                         snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 416                           libpq_gettext("Kerberos 5 authentication rejected: %*s\n"),
 417                                          err_ret->e_data->length,
 418                                          (const char *) err_ret->e_data->data);
 419 #else
 420 #error "bogus configuration"
 421 #endif
 422                 }
 423                 else
 424                 {
 425                         snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 426                                          "krb5_sendauth: %s\n", error_message(retval));
 427                 }
 428
 429                 if (err_ret)
 430                         krb5_free_error(pg_krb5_context, err_ret);
 431
 432                 ret = STATUS_ERROR;
 433         }
 434
 435         krb5_free_principal(pg_krb5_context, server);
 436
 437         if (fcntl(sock, F_SETFL, (long) flags))
 438         {
 439                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 440                                  libpq_gettext("could not restore non-blocking mode on socket: %s\n"),
 441                                  strerror(errno));
 442                 ret = STATUS_ERROR;
 443         }
 444
 445         return ret;
 446 }
 447 #endif   /* KRB5 */
 448
 449 static int
 450 pg_local_sendauth(char *PQerrormsg, PGconn *conn)
 451 {
 452 #if defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || \
 453         (defined(HAVE_STRUCT_SOCKCRED) && defined(LOCAL_CREDS)) && \
 454         !defined(HAVE_GETPEEREID) && !defined(SO_PEERCRED)
 455         char            buf;
 456         struct iovec iov;
 457         struct msghdr msg;
 458
 459 #ifdef HAVE_STRUCT_CMSGCRED
 460         /* Prevent padding */
 461         char            cmsgmem[sizeof(struct cmsghdr) + sizeof(struct cmsgcred)];
 462
 463         /* Point to start of first structure */
 464         struct cmsghdr *cmsg = (struct cmsghdr *) cmsgmem;
 465 #endif
 466 #ifdef HAVE_STRUCT_SOCKCRED
 467         /* Prevent padding */
 468         char            cmsgmem[sizeof(struct cmsghdr) + sizeof(struct sockcred)];
 469
 470         /* Point to start of first structure */
 471         struct cmsghdr *cmsg = (struct cmsghdr *) cmsgmem;
 472 #endif
 473
 474         /*
 475          * The backend doesn't care what we send here, but it wants exactly
 476          * one character to force recvmsg() to block and wait for us.
 477          */
 478         buf = '\0';
 479         iov.iov_base = &buf;
 480         iov.iov_len = 1;
 481
 482         memset(&msg, 0, sizeof(msg));
 483         msg.msg_iov = &iov;
 484         msg.msg_iovlen = 1;
 485
 486 #ifdef HAVE_STRUCT_CMSGCRED
 487         /* Create control header, FreeBSD */
 488         msg.msg_control = cmsg;
 489         msg.msg_controllen = sizeof(cmsgmem);
 490         memset(cmsg, 0, sizeof(cmsgmem));
 491         cmsg->cmsg_len = sizeof(cmsgmem);
 492         cmsg->cmsg_level = SOL_SOCKET;
 493         cmsg->cmsg_type = SCM_CREDS;
 494 #endif
 495
 496         if (sendmsg(conn->sock, &msg, 0) == -1)
 497         {
 498                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 499                                  "pg_local_sendauth: sendmsg: %s\n", strerror(errno));
 500                 return STATUS_ERROR;
 501         }
 502         return STATUS_OK;
 503 #else
 504         snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 505                 libpq_gettext("SCM_CRED authentication method not supported\n"));
 506         return STATUS_ERROR;
 507 #endif
 508 }
 509
 510 static int
 511 pg_password_sendauth(PGconn *conn, const char *password, AuthRequest areq)
 512 {
 513         int                     ret;
 514         char       *crypt_pwd;
 515
 516         /* Encrypt the password if needed. */
 517
 518         switch (areq)
 519         {
 520                 case AUTH_REQ_MD5:
 521                         {
 522                                 char       *crypt_pwd2;
 523
 524                                 if (!(crypt_pwd = malloc(MD5_PASSWD_LEN + 1)) ||
 525                                         !(crypt_pwd2 = malloc(MD5_PASSWD_LEN + 1)))
 526                                 {
 527                                         perror("malloc");
 528                                         return STATUS_ERROR;
 529                                 }
 530                                 if (!EncryptMD5(password, conn->pguser,
 531                                                                 strlen(conn->pguser), crypt_pwd2))
 532                                 {
 533                                         free(crypt_pwd);
 534                                         free(crypt_pwd2);
 535                                         return STATUS_ERROR;
 536                                 }
 537                                 if (!EncryptMD5(crypt_pwd2 + strlen("md5"), conn->md5Salt,
 538                                                                 sizeof(conn->md5Salt), crypt_pwd))
 539                                 {
 540                                         free(crypt_pwd);
 541                                         free(crypt_pwd2);
 542                                         return STATUS_ERROR;
 543                                 }
 544                                 free(crypt_pwd2);
 545                                 break;
 546                         }
 547                 case AUTH_REQ_CRYPT:
 548                         {
 549                                 char            salt[3];
 550
 551                                 StrNCpy(salt, conn->cryptSalt, 3);
 552                                 crypt_pwd = crypt(password, salt);
 553                                 break;
 554                         }
 555                 case AUTH_REQ_PASSWORD:
 556                         /* discard const so we can assign it */
 557                         crypt_pwd = (char *) password;
 558                         break;
 559                 default:
 560                         return STATUS_ERROR;
 561         }
 562         ret = pqPacketSend(conn, 'p', crypt_pwd, strlen(crypt_pwd) + 1);
 563         if (areq == AUTH_REQ_MD5)
 564                 free(crypt_pwd);
 565         return ret;
 566 }
 567
 568 /*
 569  * fe_sendauth -- client demux routine for outgoing authentication information
 570  */
 571 int
 572 fe_sendauth(AuthRequest areq, PGconn *conn, const char *hostname,
 573                         const char *password, char *PQerrormsg)
 574 {
 575 #if !defined(KRB4) && !defined(KRB5)
 576         (void) hostname;                        /* not used */
 577 #endif
 578
 579         switch (areq)
 580         {
 581                 case AUTH_REQ_OK:
 582                         break;
 583
 584                 case AUTH_REQ_KRB4:
 585 #ifdef KRB4
 586                         if (pg_krb4_sendauth(PQerrormsg, conn->sock, &conn->laddr.in,
 587                                                                  &conn->raddr.in,
 588                                                                  hostname) != STATUS_OK)
 589                         {
 590                                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 591                                         libpq_gettext("Kerberos 4 authentication failed\n"));
 592                                 return STATUS_ERROR;
 593                         }
 594                         break;
 595 #else
 596                         snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 597                          libpq_gettext("Kerberos 4 authentication not supported\n"));
 598                         return STATUS_ERROR;
 599 #endif
 600
 601                 case AUTH_REQ_KRB5:
 602 #ifdef KRB5
 603                         if (pg_krb5_sendauth(PQerrormsg, conn->sock, &conn->laddr.in,
 604                                                                  &conn->raddr.in,
 605                                                                  hostname) != STATUS_OK)
 606                         {
 607                                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 608                                         libpq_gettext("Kerberos 5 authentication failed\n"));
 609                                 return STATUS_ERROR;
 610                         }
 611                         break;
 612 #else
 613                         snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 614                          libpq_gettext("Kerberos 5 authentication not supported\n"));
 615                         return STATUS_ERROR;
 616 #endif
 617
 618                 case AUTH_REQ_MD5:
 619                 case AUTH_REQ_CRYPT:
 620                 case AUTH_REQ_PASSWORD:
 621                         if (password == NULL || *password == '\0')
 622                         {
 623                                 (void) snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 624                                                                 "fe_sendauth: no password supplied\n");
 625                                 return STATUS_ERROR;
 626                         }
 627                         if (pg_password_sendauth(conn, password, areq) != STATUS_OK)
 628                         {
 629                                 (void) snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 630                                  "fe_sendauth: error sending password authentication\n");
 631                                 return STATUS_ERROR;
 632                         }
 633                         break;
 634
 635                 case AUTH_REQ_SCM_CREDS:
 636                         if (pg_local_sendauth(PQerrormsg, conn) != STATUS_OK)
 637                                 return STATUS_ERROR;
 638                         break;
 639
 640                 default:
 641                         snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 642                                          libpq_gettext("authentication method %u not supported\n"), areq);
 643                         return STATUS_ERROR;
 644         }
 645
 646         return STATUS_OK;
 647 }
 648
 649 /*
 650  * fe_setauthsvc
 651  * fe_getauthsvc
 652  *
 653  * Set/return the authentication service currently selected for use by the
 654  * frontend. (You can only use one in the frontend, obviously.)
 655  *
 656  * NB: This is not thread-safe if different threads try to select different
 657  * authentication services!  It's OK for fe_getauthsvc to select the default,
 658  * since that will be the same for all threads, but direct application use
 659  * of fe_setauthsvc is not thread-safe.  However, use of fe_setauthsvc is
 660  * deprecated anyway...
 661  */
 662
 663 static int      pg_authsvc = -1;
 664
 665 void
 666 fe_setauthsvc(const char *name, char *PQerrormsg)
 667 {
 668         int                     i;
 669
 670         for (i = 0; i < n_authsvcs; ++i)
 671                 if (strcmp(name, authsvcs[i].name) == 0)
 672                 {
 673                         pg_authsvc = i;
 674                         break;
 675                 }
 676         if (i == n_authsvcs)
 677         {
 678                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 679                                  libpq_gettext("invalid authentication service name \"%s\", ignored\n"),
 680                                  name);
 681         }
 682         return;
 683 }
 684
 685 MsgType
 686 fe_getauthsvc(char *PQerrormsg)
 687 {
 688         if (pg_authsvc < 0 || pg_authsvc >= n_authsvcs)
 689         {
 690                 fe_setauthsvc(DEFAULT_CLIENT_AUTHSVC, PQerrormsg);
 691                 if (pg_authsvc < 0 || pg_authsvc >= n_authsvcs)
 692                 {
 693                         /* Can only get here if DEFAULT_CLIENT_AUTHSVC is misdefined */
 694                         return 0;
 695                 }
 696         }
 697         return authsvcs[pg_authsvc].msgtype;
 698 }
 699
 700 /*
 701  * fe_getauthname -- returns a pointer to dynamic space containing whatever
 702  *                                       name the user has authenticated to the system
 703  * if there is an error, return the error message in PQerrormsg
 704  */
 705 char *
 706 fe_getauthname(char *PQerrormsg)
 707 {
 708         const char *name = (char *) NULL;
 709         char       *authn = (char *) NULL;
 710         MsgType         authsvc;
 711
 712         authsvc = fe_getauthsvc(PQerrormsg);
 713
 714         /* this just guards against broken DEFAULT_CLIENT_AUTHSVC, see above */
 715         if (authsvc == 0)
 716                 return NULL;                    /* leave original error message in place */
 717
 718 #ifdef KRB4
 719         if (authsvc == STARTUP_KRB4_MSG)
 720                 name = pg_krb4_authname(PQerrormsg);
 721 #endif
 722 #ifdef KRB5
 723         if (authsvc == STARTUP_KRB5_MSG)
 724                 name = pg_krb5_authname(PQerrormsg);
 725 #endif
 726
 727         if (authsvc == STARTUP_MSG
 728                 || (authsvc == STARTUP_KRB4_MSG && !name)
 729                 || (authsvc == STARTUP_KRB5_MSG && !name))
 730         {
 731 #ifdef WIN32
 732                 char            username[128];
 733                 DWORD           namesize = sizeof(username) - 1;
 734
 735                 if (GetUserName(username, &namesize))
 736                         name = username;
 737 #else
 738                 struct passwd *pw = getpwuid(geteuid());
 739
 740                 if (pw)
 741                         name = pw->pw_name;
 742 #endif
 743         }
 744
 745         if (authsvc != STARTUP_MSG && authsvc != STARTUP_KRB4_MSG && authsvc != STARTUP_KRB5_MSG)
 746                 snprintf(PQerrormsg, PQERRORMSG_LENGTH,
 747                                  libpq_gettext("fe_getauthname: invalid authentication system: %d\n"),
 748                                  authsvc);
 749
 750         if (name && (authn = (char *) malloc(strlen(name) + 1)))
 751                 strcpy(authn, name);
 752         return authn;
 753 }