pop3.c

   1 /*@ S-nail - a mail user agent derived from Berkeley Mail.
   2  *@ POP3 (RFCs 1939, 2595) client.
   3  *
   4  * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
   5  * Copyright (c) 2012 - 2014 Steffen "Daode" Nurpmeso <sdaoden@users.sf.net>.
   6  */
   7 /*
   8  * Copyright (c) 2002
   9  *      Gunnar Ritter.  All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *      This product includes software developed by Gunnar Ritter
  22  *      and his contributors.
  23  * 4. Neither the name of Gunnar Ritter nor the names of his contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY GUNNAR RITTER AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL GUNNAR RITTER OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  */
  39
  40 #ifndef HAVE_AMALGAMATION
  41 # include "nail.h"
  42 #endif
  43
  44 EMPTY_FILE(pop3)
  45 #ifdef HAVE_POP3
  46 #ifdef HAVE_MD5
  47 # include "md5.h"
  48 #endif
  49
  50 #define POP3_ANSWER()   POP3_XANSWER(return STOP);
  51 #define POP3_XANSWER(ACTIONSTOP) \
  52 {\
  53         if (pop3_answer(mp) == STOP) {\
  54                 ACTIONSTOP;\
  55         }\
  56 }
  57
  58 #define POP3_OUT(X,Y)   POP3_XOUT(X, Y, return STOP);
  59 #define POP3_XOUT(X,Y,ACTIONSTOP) \
  60 {\
  61         if (pop3_finish(mp) == STOP) {\
  62                 ACTIONSTOP;\
  63         }\
  64         if (options & OPT_VERBOSE)\
  65                 fprintf(stderr, ">>> %s", X);\
  66         mp->mb_active |= Y;\
  67         if (swrite(&mp->mb_sock, X) == STOP) {\
  68                 ACTIONSTOP;\
  69         }\
  70 }
  71
  72 static char             *_pop3_buf;
  73 static size_t           _pop3_bufsize;
  74 static sigjmp_buf       _pop3_jmp;
  75 static sighandler_type  _pop3_savealrm;
  76 static int              _pop3_keepalive;
  77 static int volatile     _pop3_lock;
  78
  79 /* Perform entire login handshake */
  80 static enum okay        _pop3_login(struct mailbox *mp, char *xuser, char *pass,
  81                                 char const *uhp, char const *xserver);
  82
  83 /* APOP: get greeting credential or NULL */
  84 #ifdef HAVE_MD5
  85 static char *           _pop3_lookup_apop_timestamp(char const *bp);
  86 #endif
  87
  88 static bool_t           _pop3_use_starttls(char const *uhp);
  89
  90 /* APOP: shall we use it (for *uhp*)? */
  91 static bool_t           _pop3_no_apop(char const *uhp);
  92
  93 /* Several authentication methods */
  94 static enum okay        _pop3_auth_plain(struct mailbox *mp, char *xuser,
  95                                 char *pass);
  96 #ifdef HAVE_MD5
  97 static enum okay        _pop3_auth_apop(struct mailbox *mp, char *xuser,
  98                                 char *pass, char const *ts);
  99 #endif
 100
 101 static void pop3_timer_off(void);
 102 static enum okay pop3_answer(struct mailbox *mp);
 103 static enum okay pop3_finish(struct mailbox *mp);
 104 static void pop3catch(int s);
 105 static void _pop3_maincatch(int s);
 106 static enum okay pop3_noop1(struct mailbox *mp);
 107 static void pop3alarm(int s);
 108 static enum okay pop3_stat(struct mailbox *mp, off_t *size, int *cnt);
 109 static enum okay pop3_list(struct mailbox *mp, int n, size_t *size);
 110 static void pop3_init(struct mailbox *mp, int n);
 111 static void pop3_dates(struct mailbox *mp);
 112 static void pop3_setptr(struct mailbox *mp);
 113 static enum okay pop3_get(struct mailbox *mp, struct message *m,
 114                 enum needspec need);
 115 static enum okay pop3_exit(struct mailbox *mp);
 116 static enum okay pop3_delete(struct mailbox *mp, int n);
 117 static enum okay pop3_update(struct mailbox *mp);
 118
 119 static enum okay
 120 _pop3_login(struct mailbox *mp, char *xuser, char *pass, char const *uhp,
 121         char const *xserver)
 122 {
 123 #ifdef HAVE_MD5
 124         char *ts;
 125 #endif
 126         char *cp;
 127         enum okay rv = STOP;
 128
 129         /* Get the greeting, check wether APOP is advertised */
 130         POP3_XANSWER(goto jleave);
 131 #ifdef HAVE_MD5
 132         ts = _pop3_lookup_apop_timestamp(_pop3_buf);
 133 #endif
 134
 135         if ((cp = strchr(xserver, ':')) != NULL) { /* TODO GENERIC URI PARSE! */
 136                 size_t l = (size_t)(cp - xserver);
 137                 char *x = salloc(l + 1);
 138                 memcpy(x, xserver, l);
 139                 x[l] = '\0';
 140                 xserver = x;
 141         }
 142
 143         /* If not yet secured, can we upgrade to TLS? */
 144 #ifdef HAVE_SSL
 145         if (mp->mb_sock.s_use_ssl == 0 && _pop3_use_starttls(uhp)) {
 146                 POP3_XOUT("STLS\r\n", MB_COMD, goto jleave);
 147                 POP3_XANSWER(goto jleave);
 148                 if (ssl_open(xserver, &mp->mb_sock, uhp) != OKAY)
 149                         goto jleave;
 150         }
 151 #else
 152         if (_pop3_use_starttls(uhp)) {
 153                 fprintf(stderr, "No SSL support compiled in.\n");
 154                 goto jleave;
 155         }
 156 #endif
 157
 158         /* Use the APOP single roundtrip? */
 159         if (! _pop3_no_apop(uhp)) {
 160 #ifdef HAVE_MD5
 161                 if (ts != NULL) {
 162                         rv = _pop3_auth_apop(mp, xuser, pass, ts);
 163                         if (rv != OKAY)
 164                                 fprintf(stderr, tr(276,
 165                                         "POP3 `APOP' authentication failed, "
 166                                         "maybe try setting *pop3-no-apop*\n"));
 167                         goto jleave;
 168                 } else
 169 #endif
 170                 if (options & OPT_VERBOSE)
 171                         fprintf(stderr, tr(204, "No POP3 `APOP' support "
 172                                 "available, sending password in clear text\n"));
 173         }
 174         rv = _pop3_auth_plain(mp, xuser, pass);
 175 jleave:
 176         return rv;
 177 }
 178
 179 static char *
 180 _pop3_lookup_apop_timestamp(char const *bp)
 181 {
 182         /*
 183          * RFC 1939:
 184          * A POP3 server which implements the APOP command will include
 185          * a timestamp in its banner greeting.  The syntax of the timestamp
 186          * corresponds to the `msg-id' in [RFC822]
 187          * RFC 822:
 188          * msg-id       = "<" addr-spec ">"
 189          * addr-spec    = local-part "@" domain
 190          */
 191         char const *cp, *ep;
 192         size_t tl;
 193         char *rp = NULL;
 194         bool_t hadat = FAL0;
 195
 196         if ((cp = strchr(bp, '<')) == NULL)
 197                 goto jleave;
 198
 199         /* xxx What about malformed APOP timestamp (<@>) here? */
 200         for (ep = cp; *ep; ep++) {
 201                 if (spacechar(*ep))
 202                         goto jleave;
 203                 else if (*ep == '@')
 204                         hadat = TRU1;
 205                 else if (*ep == '>') {
 206                         if (! hadat)
 207                                 goto jleave;
 208                         break;
 209                 }
 210         }
 211         if (*ep != '>')
 212                 goto jleave;
 213
 214         tl = (size_t)(++ep - cp);
 215         rp = salloc(tl + 1);
 216         memcpy(rp, cp, tl);
 217         rp[tl] = '\0';
 218 jleave:
 219         return rp;
 220 }
 221
 222 static bool_t
 223 _pop3_use_starttls(char const *uhp)
 224 {
 225         char *var;
 226
 227         if (ok_blook(pop3_use_starttls))
 228                 return TRU1;
 229         var = savecat("pop3-use-starttls-", uhp);
 230         return vok_blook(var);
 231 }
 232
 233 static bool_t
 234 _pop3_no_apop(char const *uhp)
 235 {
 236         bool_t ret;
 237
 238         if (!(ret = ok_blook(pop3_no_apop))) {
 239 #define __S     "pop3-no-apop-"
 240 #define __SL    sizeof(__S)
 241                 size_t i = strlen(uhp);
 242                 char *var = ac_alloc(i + __SL);
 243                 memcpy(var, __S, __SL - 1);
 244                 memcpy(var + __SL - 1, uhp, i + 1);
 245                 ret = vok_blook(var);
 246                 ac_free(var);
 247 #undef __SL
 248 #undef __S
 249         }
 250         return ret;
 251 }
 252
 253 #ifdef HAVE_MD5
 254 static enum okay
 255 _pop3_auth_apop(struct mailbox *mp, char *xuser, char *pass, char const *ts)
 256 {
 257         enum okay rv = STOP;
 258         unsigned char digest[16];
 259         char hex[MD5TOHEX_SIZE];
 260         md5_ctx ctx;
 261         size_t tl, i;
 262         char *user, *cp;
 263
 264         for (tl = strlen(ts);;) {
 265                 user = xuser;
 266                 if (! getcredentials(&user, &pass))
 267                         break;
 268
 269                 md5_init(&ctx);
 270                 md5_update(&ctx, (unsigned char*)UNCONST(ts), tl);
 271                 md5_update(&ctx, (unsigned char*)pass, strlen(pass));
 272                 md5_final(digest, &ctx);
 273                 md5tohex(hex, digest);
 274
 275                 i = strlen(user);
 276                 cp = ac_alloc(5 + i + 1 + MD5TOHEX_SIZE + 3);
 277
 278                 memcpy(cp, "APOP ", 5);
 279                 memcpy(cp + 5, user, i);
 280                 i += 5;
 281                 cp[i++] = ' ';
 282                 memcpy(cp + i, hex, MD5TOHEX_SIZE);
 283                 i += MD5TOHEX_SIZE;
 284                 memcpy(cp + i, "\r\n\0", 3);
 285                 POP3_XOUT(cp, MB_COMD, goto jcont);
 286                 POP3_XANSWER(goto jcont);
 287                 rv = OKAY;
 288 jcont:
 289                 ac_free(cp);
 290                 if (rv == OKAY)
 291                         break;
 292                 pass = NULL;
 293         }
 294         return rv;
 295 }
 296 #endif /* HAVE_MD5 */
 297
 298 static enum okay
 299 _pop3_auth_plain(struct mailbox *mp, char *xuser, char *pass)
 300 {
 301         enum okay rv = STOP;
 302         char *user, *cp;
 303         size_t ul, pl;
 304
 305         /* The USER/PASS plain text version */
 306         for (;;) {
 307                 user = xuser;
 308                 if (! getcredentials(&user, &pass))
 309                         break;
 310
 311                 ul = strlen(user);
 312                 pl = strlen(pass);
 313                 cp = ac_alloc(MAX(ul, pl) + 5 + 2 +1);
 314
 315                 memcpy(cp, "USER ", 5);
 316                 memcpy(cp + 5, user, ul);
 317                 memcpy(cp + 5 + ul, "\r\n\0", 3);
 318                 POP3_XOUT(cp, MB_COMD, goto jcont);
 319                 POP3_XANSWER(goto jcont);
 320
 321                 memcpy(cp, "PASS ", 5);
 322                 memcpy(cp + 5, pass, pl);
 323                 memcpy(cp + 5 + pl, "\r\n\0", 3);
 324                 POP3_XOUT(cp, MB_COMD, goto jcont);
 325                 POP3_XANSWER(goto jcont);
 326                 rv = OKAY;
 327 jcont:
 328                 ac_free(cp);
 329                 if (rv == OKAY)
 330                         break;
 331                 pass = NULL;
 332         }
 333         return rv;
 334 }
 335
 336 static void
 337 pop3_timer_off(void)
 338 {
 339         if (_pop3_keepalive > 0) {
 340                 alarm(0);
 341                 safe_signal(SIGALRM, _pop3_savealrm);
 342         }
 343 }
 344
 345 static enum okay
 346 pop3_answer(struct mailbox *mp)
 347 {
 348         int sz;
 349         enum okay ok = STOP;
 350
 351 retry:
 352         if ((sz = sgetline(&_pop3_buf, &_pop3_bufsize, NULL, &mp->mb_sock))
 353                         > 0) {
 354                 if ((mp->mb_active & (MB_COMD|MB_MULT)) == MB_MULT)
 355                         goto multiline;
 356                 if (options & OPT_VERBOSE)
 357                         fputs(_pop3_buf, stderr);
 358                 switch (*_pop3_buf) {
 359                 case '+':
 360                         ok = OKAY;
 361                         mp->mb_active &= ~MB_COMD;
 362                         break;
 363                 case '-':
 364                         ok = STOP;
 365                         mp->mb_active = MB_NONE;
 366                         fprintf(stderr, tr(218, "POP3 error: %s"), _pop3_buf);
 367                         break;
 368                 default:
 369                         /*
 370                          * If the answer starts neither with '+' nor with
 371                          * '-', it must be part of a multiline response,
 372                          * e. g. because the user interrupted a file
 373                          * download. Get lines until a single dot appears.
 374                          */
 375 multiline:
 376                         while (_pop3_buf[0] != '.' || _pop3_buf[1] != '\r' ||
 377                                         _pop3_buf[2] != '\n' ||
 378                                         _pop3_buf[3] != '\0') {
 379                                 sz = sgetline(&_pop3_buf, &_pop3_bufsize,
 380                                                 NULL, &mp->mb_sock);
 381                                 if (sz <= 0)
 382                                         goto eof;
 383                         }
 384                         mp->mb_active &= ~MB_MULT;
 385                         if (mp->mb_active != MB_NONE)
 386                                 goto retry;
 387                 }
 388         } else {
 389         eof:    ok = STOP;
 390                 mp->mb_active = MB_NONE;
 391         }
 392         return ok;
 393 }
 394
 395 static enum okay
 396 pop3_finish(struct mailbox *mp)
 397 {
 398         while (mp->mb_sock.s_fd > 0 && mp->mb_active != MB_NONE)
 399                 (void)pop3_answer(mp);
 400         return OKAY;
 401 }
 402
 403 static void
 404 pop3catch(int s)
 405 {
 406         termios_state_reset();
 407         switch (s) {
 408         case SIGINT:
 409                 fprintf(stderr, tr(102, "Interrupt\n"));
 410                 siglongjmp(_pop3_jmp, 1);
 411                 break;
 412         case SIGPIPE:
 413                 fprintf(stderr, "Received SIGPIPE during POP3 operation\n");
 414                 break;
 415         }
 416 }
 417
 418 static void
 419 _pop3_maincatch(int s)
 420 {
 421         (void)s;
 422         if (interrupts++ == 0) {
 423                 fprintf(stderr, tr(102, "Interrupt\n"));
 424                 return;
 425         }
 426         onintr(0);
 427 }
 428
 429 static enum okay
 430 pop3_noop1(struct mailbox *mp)
 431 {
 432         POP3_OUT("NOOP\r\n", MB_COMD)
 433         POP3_ANSWER()
 434         return OKAY;
 435 }
 436
 437 FL enum okay
 438 pop3_noop(void)
 439 {
 440         sighandler_type volatile saveint, savepipe;
 441         enum okay ok = STOP;
 442
 443         _pop3_lock = 1;
 444         if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 445                 safe_signal(SIGINT, &_pop3_maincatch);
 446         savepipe = safe_signal(SIGPIPE, SIG_IGN);
 447         if (sigsetjmp(_pop3_jmp, 1) == 0) {
 448                 if (savepipe != SIG_IGN)
 449                         safe_signal(SIGPIPE, pop3catch);
 450                 ok = pop3_noop1(&mb);
 451         }
 452         safe_signal(SIGINT, saveint);
 453         safe_signal(SIGPIPE, savepipe);
 454         _pop3_lock = 0;
 455         return ok;
 456 }
 457
 458 /*ARGSUSED*/
 459 static void
 460 pop3alarm(int s)
 461 {
 462         sighandler_type volatile saveint, savepipe;
 463         UNUSED(s);
 464
 465         if (_pop3_lock++ == 0) {
 466                 if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 467                         safe_signal(SIGINT, &_pop3_maincatch);
 468                 savepipe = safe_signal(SIGPIPE, SIG_IGN);
 469                 if (sigsetjmp(_pop3_jmp, 1)) {
 470                         safe_signal(SIGINT, saveint);
 471                         safe_signal(SIGPIPE, savepipe);
 472                         goto brk;
 473                 }
 474                 if (savepipe != SIG_IGN)
 475                         safe_signal(SIGPIPE, pop3catch);
 476                 if (pop3_noop1(&mb) != OKAY) {
 477                         safe_signal(SIGINT, saveint);
 478                         safe_signal(SIGPIPE, savepipe);
 479                         goto out;
 480                 }
 481                 safe_signal(SIGINT, saveint);
 482                 safe_signal(SIGPIPE, savepipe);
 483         }
 484 brk:
 485         alarm(_pop3_keepalive);
 486 out:
 487         --_pop3_lock;
 488 }
 489
 490 static enum okay
 491 pop3_stat(struct mailbox *mp, off_t *size, int *cnt)
 492 {
 493         char *cp;
 494         enum okay ok = OKAY;
 495
 496         POP3_OUT("STAT\r\n", MB_COMD)
 497         POP3_ANSWER()
 498         for (cp = _pop3_buf; *cp != '\0' && !spacechar(*cp); ++cp)
 499                 ;
 500         while (*cp != '\0' && spacechar(*cp))
 501                 ++cp;
 502
 503         if (*cp != '\0') {
 504                 *cnt = (int)strtol(cp, NULL, 10);
 505                 while (*cp != '\0' && !spacechar(*cp))
 506                         ++cp;
 507                 while (*cp != '\0' && spacechar(*cp))
 508                         ++cp;
 509                 if (*cp != '\0')
 510                         *size = (int)strtol(cp, NULL, 10);
 511                 else
 512                         ok = STOP;
 513         } else
 514                 ok = STOP;
 515
 516         if (ok == STOP)
 517                 fprintf(stderr, tr(260, "invalid POP3 STAT response: %s\n"),
 518                         _pop3_buf);
 519         return ok;
 520 }
 521
 522 static enum okay
 523 pop3_list(struct mailbox *mp, int n, size_t *size)
 524 {
 525         char o[LINESIZE], *cp;
 526
 527         snprintf(o, sizeof o, "LIST %u\r\n", n);
 528         POP3_OUT(o, MB_COMD)
 529         POP3_ANSWER()
 530         for (cp = _pop3_buf; *cp != '\0' && !spacechar(*cp); ++cp)
 531                 ;
 532         while (*cp != '\0' && spacechar(*cp))
 533                 ++cp;
 534         while (*cp != '\0' && !spacechar(*cp))
 535                 ++cp;
 536         while (*cp != '\0' && spacechar(*cp))
 537                 ++cp;
 538         if (*cp != '\0')
 539                 *size = (size_t)strtol(cp, NULL, 10);
 540         else
 541                 *size = 0;
 542         return OKAY;
 543 }
 544
 545 static void
 546 pop3_init(struct mailbox *mp, int n)
 547 {
 548         struct message *m = &message[n];
 549         char *cp;
 550
 551         m->m_flag = MUSED|MNEW|MNOFROM|MNEWEST;
 552         m->m_block = 0;
 553         m->m_offset = 0;
 554         pop3_list(mp, m - message + 1, &m->m_xsize);
 555         if ((cp = hfield1("status", m)) != NULL) {
 556                 while (*cp != '\0') {
 557                         if (*cp == 'R')
 558                                 m->m_flag |= MREAD;
 559                         else if (*cp == 'O')
 560                                 m->m_flag &= ~MNEW;
 561                         cp++;
 562                 }
 563         }
 564 }
 565
 566 /*ARGSUSED*/
 567 static void
 568 pop3_dates(struct mailbox *mp)
 569 {
 570         int     i;
 571         (void)mp;
 572
 573         for (i = 0; i < msgCount; i++)
 574                 substdate(&message[i]);
 575 }
 576
 577 static void
 578 pop3_setptr(struct mailbox *mp)
 579 {
 580         int i;
 581
 582         message = scalloc(msgCount + 1, sizeof *message);
 583         for (i = 0; i < msgCount; i++)
 584                 pop3_init(mp, i);
 585         setdot(message);
 586         message[msgCount].m_size = 0;
 587         message[msgCount].m_lines = 0;
 588         pop3_dates(mp);
 589 }
 590
 591 FL int
 592 pop3_setfile(const char *server, int nmail, int isedit)
 593 {
 594         struct sock     so;
 595         sighandler_type saveint;
 596         sighandler_type savepipe;
 597         char * volatile user, * volatile pass;
 598         const char *cp, *uhp, * volatile sp = server;
 599         int use_ssl = 0;
 600
 601         if (nmail)
 602                 return 1;
 603         if (strncmp(sp, "pop3://", 7) == 0) {
 604                 sp = &sp[7];
 605                 use_ssl = 0;
 606 #ifdef HAVE_SSL
 607         } else if (strncmp(sp, "pop3s://", 8) == 0) {
 608                 sp = &sp[8];
 609                 use_ssl = 1;
 610 #endif
 611         }
 612         uhp = sp;
 613         pass = lookup_password_for_token(uhp);
 614         if ((cp = last_at_before_slash(sp)) != NULL) {
 615                 user = salloc(cp - sp + 1);
 616                 memcpy(user, sp, cp - sp);
 617                 user[cp - sp] = '\0';
 618                 sp = &cp[1];
 619                 user = urlxdec(user);
 620         } else
 621                 user = NULL;
 622         if (sopen(sp, &so, use_ssl, uhp, (use_ssl ? "pop3s" : "pop3"))
 623                         != OKAY) {
 624                 return -1;
 625         }
 626         quit();
 627         edit = (isedit != 0);
 628         if (mb.mb_sock.s_fd >= 0)
 629                 sclose(&mb.mb_sock);
 630         if (mb.mb_itf) {
 631                 fclose(mb.mb_itf);
 632                 mb.mb_itf = NULL;
 633         }
 634         if (mb.mb_otf) {
 635                 fclose(mb.mb_otf);
 636                 mb.mb_otf = NULL;
 637         }
 638         initbox(server);
 639         mb.mb_type = MB_VOID;
 640         _pop3_lock = 1;
 641         mb.mb_sock = so;
 642         saveint = safe_signal(SIGINT, SIG_IGN);
 643         savepipe = safe_signal(SIGPIPE, SIG_IGN);
 644         if (sigsetjmp(_pop3_jmp, 1)) {
 645                 sclose(&mb.mb_sock);
 646                 safe_signal(SIGINT, saveint);
 647                 safe_signal(SIGPIPE, savepipe);
 648                 _pop3_lock = 0;
 649                 return 1;
 650         }
 651         if (saveint != SIG_IGN)
 652                 safe_signal(SIGINT, pop3catch);
 653         if (savepipe != SIG_IGN)
 654                 safe_signal(SIGPIPE, pop3catch);
 655         if ((cp = ok_vlook(pop3_keepalive)) != NULL) {
 656                 if ((_pop3_keepalive = (int)strtol(cp, NULL, 10)) > 0) {
 657                         _pop3_savealrm = safe_signal(SIGALRM, pop3alarm);
 658                         alarm(_pop3_keepalive);
 659                 }
 660         }
 661         mb.mb_sock.s_desc = "POP3";
 662         mb.mb_sock.s_onclose = pop3_timer_off;
 663         if (_pop3_login(&mb, user, pass, uhp, sp) != OKAY ||
 664                         pop3_stat(&mb, &mailsize, &msgCount) != OKAY) {
 665                 sclose(&mb.mb_sock);
 666                 pop3_timer_off();
 667                 safe_signal(SIGINT, saveint);
 668                 safe_signal(SIGPIPE, savepipe);
 669                 _pop3_lock = 0;
 670                 return 1;
 671         }
 672         mb.mb_type = MB_POP3;
 673         mb.mb_perm = (options & OPT_R_FLAG) ? 0 : MB_DELE;
 674         pop3_setptr(&mb);
 675         setmsize(msgCount);
 676         sawcom = FAL0;
 677         safe_signal(SIGINT, saveint);
 678         safe_signal(SIGPIPE, savepipe);
 679         _pop3_lock = 0;
 680         if (!edit && msgCount == 0) {
 681                 if (mb.mb_type == MB_POP3 && !ok_blook(emptystart))
 682                         fprintf(stderr, tr(258, "No mail at %s\n"), server);
 683                 return 1;
 684         }
 685         return 0;
 686 }
 687
 688 static enum okay
 689 pop3_get(struct mailbox *mp, struct message *m, enum needspec volatile need)
 690 {
 691         sighandler_type volatile saveint = SIG_IGN, savepipe = SIG_IGN;
 692         off_t offset;
 693         char o[LINESIZE], *line = NULL, *lp;
 694         size_t linesize = 0, linelen, size;
 695         int number = m - message + 1, emptyline = 0, lines;
 696
 697         if (mp->mb_sock.s_fd < 0) {
 698                 fprintf(stderr, tr(219, "POP3 connection already closed.\n"));
 699                 return STOP;
 700         }
 701         if (_pop3_lock++ == 0) {
 702                 if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 703                         safe_signal(SIGINT, &_pop3_maincatch);
 704                 savepipe = safe_signal(SIGPIPE, SIG_IGN);
 705                 if (sigsetjmp(_pop3_jmp, 1)) {
 706                         safe_signal(SIGINT, saveint);
 707                         safe_signal(SIGPIPE, savepipe);
 708                         _pop3_lock--;
 709                         return STOP;
 710                 }
 711                 if (savepipe != SIG_IGN)
 712                         safe_signal(SIGPIPE, pop3catch);
 713         }
 714         fseek(mp->mb_otf, 0L, SEEK_END);
 715         offset = ftell(mp->mb_otf);
 716 retry:  switch (need) {
 717         case NEED_HEADER:
 718                 snprintf(o, sizeof o, "TOP %u 0\r\n", number);
 719                 break;
 720         case NEED_BODY:
 721                 snprintf(o, sizeof o, "RETR %u\r\n", number);
 722                 break;
 723         case NEED_UNSPEC:
 724                 abort();
 725         }
 726         POP3_OUT(o, MB_COMD|MB_MULT)
 727         if (pop3_answer(mp) == STOP) {
 728                 if (need == NEED_HEADER) {
 729                         /*
 730                          * The TOP POP3 command is optional, so retry
 731                          * with the entire message.
 732                          */
 733                         need = NEED_BODY;
 734                         goto retry;
 735                 }
 736                 if (interrupts)
 737                         onintr(0);
 738                 return STOP;
 739         }
 740         size = 0;
 741         lines = 0;
 742         while (sgetline(&line, &linesize, &linelen, &mp->mb_sock) > 0) {
 743                 if (line[0] == '.' && line[1] == '\r' && line[2] == '\n' &&
 744                                 line[3] == '\0') {
 745                         mp->mb_active &= ~MB_MULT;
 746                         break;
 747                 }
 748                 if (line[0] == '.') {
 749                         lp = &line[1];
 750                         linelen--;
 751                 } else
 752                         lp = line;
 753                 /* TODO >>
 754                  * Need to mask 'From ' lines. This cannot be done properly
 755                  * since some servers pass them as 'From ' and others as
 756                  * '>From '. Although one could identify the first kind of
 757                  * server in principle, it is not possible to identify the
 758                  * second as '>From ' may also come from a server of the
 759                  * first type as actual data. So do what is absolutely
 760                  * necessary only - mask 'From '.
 761                  *
 762                  * If the line is the first line of the message header, it
 763                  * is likely a real 'From ' line. In this case, it is just
 764                  * ignored since it violates all standards.
 765                  * TODO i have *never* seen the latter?!?!?
 766                  * TODO <<
 767                  */
 768                 /*
 769                  * Since we simply copy over data without doing any transfer
 770                  * encoding reclassification/adjustment we *have* to perform
 771                  * RFC 4155 compliant From_ quoting here
 772                  */
 773                 if (is_head(lp, linelen)) {
 774                         if (lines == 0)
 775                                 continue;
 776                         fputc('>', mp->mb_otf);
 777                         ++size;
 778                 }
 779                 lines++;
 780                 if (lp[linelen-1] == '\n' && (linelen == 1 ||
 781                                         lp[linelen-2] == '\r')) {
 782                         emptyline = linelen <= 2;
 783                         if (linelen > 2)
 784                                 fwrite(lp, 1, linelen - 2, mp->mb_otf);
 785                         fputc('\n', mp->mb_otf);
 786                         size += linelen - 1;
 787                 } else {
 788                         emptyline = 0;
 789                         fwrite(lp, 1, linelen, mp->mb_otf);
 790                         size += linelen;
 791                 }
 792         }
 793         if (!emptyline) {
 794                 /*
 795                  * This is very ugly; but some POP3 daemons don't end a
 796                  * message with \r\n\r\n, and we need \n\n for mbox format.
 797                  */
 798                 fputc('\n', mp->mb_otf);
 799                 lines++;
 800                 size++;
 801         }
 802         m->m_size = size;
 803         m->m_lines = lines;
 804         m->m_block = mailx_blockof(offset);
 805         m->m_offset = mailx_offsetof(offset);
 806         fflush(mp->mb_otf);
 807         switch (need) {
 808         case NEED_HEADER:
 809                 m->m_have |= HAVE_HEADER;
 810                 break;
 811         case NEED_BODY:
 812                 m->m_have |= HAVE_HEADER|HAVE_BODY;
 813                 m->m_xlines = m->m_lines;
 814                 m->m_xsize = m->m_size;
 815                 break;
 816         case NEED_UNSPEC:
 817                 break;
 818         }
 819         if (line)
 820                 free(line);
 821         if (saveint != SIG_IGN)
 822                 safe_signal(SIGINT, saveint);
 823         if (savepipe != SIG_IGN)
 824                 safe_signal(SIGPIPE, savepipe);
 825         _pop3_lock--;
 826         if (interrupts)
 827                 onintr(0);
 828         return OKAY;
 829 }
 830
 831 FL enum okay
 832 pop3_header(struct message *m)
 833 {
 834         return pop3_get(&mb, m,
 835                 ok_blook(pop3_bulk_load) ? NEED_BODY : NEED_HEADER);
 836 }
 837
 838 FL enum okay
 839 pop3_body(struct message *m)
 840 {
 841         return pop3_get(&mb, m, NEED_BODY);
 842 }
 843
 844 static enum okay
 845 pop3_exit(struct mailbox *mp)
 846 {
 847         POP3_OUT("QUIT\r\n", MB_COMD)
 848         POP3_ANSWER()
 849         return OKAY;
 850 }
 851
 852 static enum okay
 853 pop3_delete(struct mailbox *mp, int n)
 854 {
 855         char o[LINESIZE];
 856
 857         snprintf(o, sizeof o, "DELE %u\r\n", n);
 858         POP3_OUT(o, MB_COMD)
 859         POP3_ANSWER()
 860         return OKAY;
 861 }
 862
 863 static enum okay
 864 pop3_update(struct mailbox *mp)
 865 {
 866         struct message *m;
 867         int dodel, c, gotcha, held;
 868
 869         if (!edit) {
 870                 holdbits();
 871                 for (m = &message[0], c = 0; m < &message[msgCount]; m++) {
 872                         if (m->m_flag & MBOX)
 873                                 c++;
 874                 }
 875                 if (c > 0)
 876                         makembox();
 877         }
 878         for (m = &message[0], gotcha=0, held=0; m < &message[msgCount]; m++) {
 879                 if (edit) {
 880                         dodel = m->m_flag & MDELETED;
 881                 } else {
 882                         dodel = !((m->m_flag&MPRESERVE) ||
 883                                         (m->m_flag&MTOUCH) == 0);
 884                 }
 885                 if (dodel) {
 886                         pop3_delete(mp, m - message + 1);
 887                         gotcha++;
 888                 } else
 889                         held++;
 890         }
 891         if (gotcha && edit) {
 892                 printf(tr(168, "\"%s\" "), displayname);
 893                 printf((ok_blook(bsdcompat) || ok_blook(bsdmsgs))
 894                         ? tr(170, "complete\n") : tr(212, "updated.\n"));
 895         } else if (held && !edit) {
 896                 if (held == 1)
 897                         printf(tr(155, "Held 1 message in %s\n"), displayname);
 898                 else
 899                         printf(tr(156, "Held %d messages in %s\n"), held,
 900                                 displayname);
 901         }
 902         fflush(stdout);
 903         return OKAY;
 904 }
 905
 906 FL void
 907 pop3_quit(void)
 908 {
 909         sighandler_type volatile saveint, savepipe;
 910
 911         if (mb.mb_sock.s_fd < 0) {
 912                 fprintf(stderr, tr(219,
 913                                 "POP3 connection already closed.\n"));
 914                 return;
 915         }
 916         _pop3_lock = 1;
 917         saveint = safe_signal(SIGINT, SIG_IGN);
 918         savepipe = safe_signal(SIGPIPE, SIG_IGN);
 919         if (sigsetjmp(_pop3_jmp, 1)) {
 920                 safe_signal(SIGINT, saveint);
 921                 safe_signal(SIGPIPE, saveint);
 922                 _pop3_lock = 0;
 923                 return;
 924         }
 925         if (saveint != SIG_IGN)
 926                 safe_signal(SIGINT, pop3catch);
 927         if (savepipe != SIG_IGN)
 928                 safe_signal(SIGPIPE, pop3catch);
 929         pop3_update(&mb);
 930         pop3_exit(&mb);
 931         sclose(&mb.mb_sock);
 932         safe_signal(SIGINT, saveint);
 933         safe_signal(SIGPIPE, savepipe);
 934         _pop3_lock = 0;
 935 }
 936 #endif /* HAVE_POP3 */