1/* 2 * Copyright (c) 1998-2003, 2006, 2013 Proofpoint, Inc. and its suppliers. 3 * All rights reserved. 4 * Copyright (c) 1994, 1996-1997 Eric P. Allman. All rights reserved. 5 * Copyright (c) 1994 6 * The Regents of the University of California. All rights reserved. 7 * 8 * By using this file, you agree to the terms and conditions set 9 * forth in the LICENSE file which can be found at the top level of 10 * the sendmail distribution. 11 * 12 */ 13 14#include <sendmail.h> 15#include <string.h> 16 17SM_RCSID("@(#)$Id: mime.c,v 8.149 2013-11-22 20:51:56 ca Exp $") 18 19/* 20** MIME support. 21** 22** I am indebted to John Beck of Hewlett-Packard, who contributed 23** his code to me for inclusion. As it turns out, I did not use 24** his code since he used a "minimum change" approach that used 25** several temp files, and I wanted a "minimum impact" approach 26** that would avoid copying. However, looking over his code 27** helped me cement my understanding of the problem. 28** 29** I also looked at, but did not directly use, Nathaniel 30** Borenstein's "code.c" module. Again, it functioned as 31** a file-to-file translator, which did not fit within my 32** design bounds, but it was a useful base for understanding 33** the problem. 34*/ 35 36/* use "old" mime 7 to 8 algorithm by default */ 37#ifndef MIME7TO8_OLD 38# define MIME7TO8_OLD 1 39#endif 40 41#if MIME8TO7 42static int isboundary __P((char *, char **)); 43static int mimeboundary __P((char *, char **)); 44static int mime_getchar __P((SM_FILE_T *, char **, int *)); 45static int mime_getchar_crlf __P((SM_FILE_T *, char **, int *)); 46 47/* character set for hex and base64 encoding */ 48static char Base16Code[] = "0123456789ABCDEF"; 49static char Base64Code[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; 50 51/* types of MIME boundaries */ 52# define MBT_SYNTAX 0 /* syntax error */ 53# define MBT_NOTSEP 1 /* not a boundary */ 54# define MBT_INTERMED 2 /* intermediate boundary (no trailing --) */ 55# define MBT_FINAL 3 /* final boundary (trailing -- included) */ 56 57static char *MimeBoundaryNames[] = 58{ 59 "SYNTAX", "NOTSEP", "INTERMED", "FINAL" 60}; 61 62static bool MapNLtoCRLF; 63 64/* 65** MIME8TO7 -- output 8 bit body in 7 bit format 66** 67** The header has already been output -- this has to do the 68** 8 to 7 bit conversion. It would be easy if we didn't have 69** to deal with nested formats (multipart/xxx and message/rfc822). 70** 71** We won't be called if we don't have to do a conversion, and 72** appropriate MIME-Version: and Content-Type: fields have been 73** output. Any Content-Transfer-Encoding: field has not been 74** output, and we can add it here. 75** 76** Parameters: 77** mci -- mailer connection information. 78** header -- the header for this body part. 79** e -- envelope. 80** boundaries -- the currently pending message boundaries. 81** NULL if we are processing the outer portion. 82** flags -- to tweak processing. 83** level -- recursion level. 84** 85** Returns: 86** An indicator of what terminated the message part: 87** MBT_FINAL -- the final boundary 88** MBT_INTERMED -- an intermediate boundary 89** MBT_NOTSEP -- an end of file 90** SM_IO_EOF -- I/O error occurred 91*/ 92 93struct args 94{ 95 char *a_field; /* name of field */ 96 char *a_value; /* value of that field */ 97}; 98 99int 100mime8to7(mci, header, e, boundaries, flags, level) 101 register MCI *mci; 102 HDR *header; 103 register ENVELOPE *e; 104 char **boundaries; 105 int flags; 106 int level; 107{ 108 register char *p; 109 int linelen; 110 int blen; 111 int bt; 112 off_t offset; 113 size_t sectionsize, sectionhighbits; 114 int i; 115 char *type; 116 char *subtype; 117 char *cte; 118 char **pvp; 119 int argc = 0; 120 char *bp; 121 bool use_qp = false; 122 struct args argv[MAXMIMEARGS]; 123 char bbuf[128]; 124 char buf[MAXLINE]; 125 char pvpbuf[MAXLINE]; 126 extern unsigned char MimeTokenTab[256]; 127 128 if (level > MAXMIMENESTING) 129 { 130 if (!bitset(EF_TOODEEP, e->e_flags)) 131 { 132 if (tTd(43, 4)) 133 sm_dprintf("mime8to7: too deep, level=%d\n", 134 level); 135 usrerr("mime8to7: recursion level %d exceeded", 136 level); 137 e->e_flags |= EF_DONT_MIME|EF_TOODEEP; 138 } 139 } 140 if (tTd(43, 1)) 141 { 142 sm_dprintf("mime8to7: flags = %x, boundaries =", flags); 143 if (boundaries[0] == NULL) 144 sm_dprintf(" <none>"); 145 else 146 { 147 for (i = 0; boundaries[i] != NULL; i++) 148 sm_dprintf(" %s", boundaries[i]); 149 } 150 sm_dprintf("\n"); 151 } 152 MapNLtoCRLF = true; 153 p = hvalue("Content-Transfer-Encoding", header); 154 if (p == NULL || 155 (pvp = prescan(p, '\0', pvpbuf, sizeof(pvpbuf), NULL, 156 MimeTokenTab, false)) == NULL || 157 pvp[0] == NULL) 158 { 159 cte = NULL; 160 } 161 else 162 { 163 cataddr(pvp, NULL, buf, sizeof(buf), '\0', false); 164 cte = sm_rpool_strdup_x(e->e_rpool, buf); 165 } 166 167 type = subtype = NULL; 168 p = hvalue("Content-Type", header); 169 if (p == NULL) 170 { 171 if (bitset(M87F_DIGEST, flags)) 172 p = "message/rfc822"; 173 else 174 p = "text/plain"; 175 } 176 if (p != NULL && 177 (pvp = prescan(p, '\0', pvpbuf, sizeof(pvpbuf), NULL, 178 MimeTokenTab, false)) != NULL && 179 pvp[0] != NULL) 180 { 181 if (tTd(43, 40)) 182 { 183 for (i = 0; pvp[i] != NULL; i++) 184 sm_dprintf("pvp[%d] = \"%s\"\n", i, pvp[i]); 185 } 186 type = *pvp++; 187 if (*pvp != NULL && strcmp(*pvp, "/") == 0 && 188 *++pvp != NULL) 189 { 190 subtype = *pvp++; 191 } 192 193 /* break out parameters */ 194 while (*pvp != NULL && argc < MAXMIMEARGS) 195 { 196 /* skip to semicolon separator */ 197 while (*pvp != NULL && strcmp(*pvp, ";") != 0) 198 pvp++; 199 if (*pvp++ == NULL || *pvp == NULL) 200 break; 201 202 /* complain about empty values */ 203 if (strcmp(*pvp, ";") == 0) 204 { 205 usrerr("mime8to7: Empty parameter in Content-Type header"); 206 207 /* avoid bounce loops */ 208 e->e_flags |= EF_DONT_MIME; 209 continue; 210 } 211 212 /* extract field name */ 213 argv[argc].a_field = *pvp++; 214 215 /* see if there is a value */ 216 if (*pvp != NULL && strcmp(*pvp, "=") == 0 && 217 (*++pvp == NULL || strcmp(*pvp, ";") != 0)) 218 { 219 argv[argc].a_value = *pvp; 220 argc++; 221 } 222 } 223 } 224 225 /* check for disaster cases */ 226 if (type == NULL) 227 type = "-none-"; 228 if (subtype == NULL) 229 subtype = "-none-"; 230 231 /* don't propagate some flags more than one level into the message */ 232 flags &= ~M87F_DIGEST; 233 234 /* 235 ** Check for cases that can not be encoded. 236 ** 237 ** For example, you can't encode certain kinds of types 238 ** or already-encoded messages. If we find this case, 239 ** just copy it through. 240 */ 241 242 (void) sm_snprintf(buf, sizeof(buf), "%.100s/%.100s", type, subtype); 243 if (wordinclass(buf, 'n') || (cte != NULL && !wordinclass(cte, 'e'))) 244 flags |= M87F_NO8BIT; 245 246# ifdef USE_B_CLASS 247 if (wordinclass(buf, 'b') || wordinclass(type, 'b')) 248 MapNLtoCRLF = false; 249# endif 250 if (wordinclass(buf, 'q') || wordinclass(type, 'q')) 251 use_qp = true; 252 253 /* 254 ** Multipart requires special processing. 255 ** 256 ** Do a recursive descent into the message. 257 */ 258 259 if (sm_strcasecmp(type, "multipart") == 0 && 260 (!bitset(M87F_NO8BIT, flags) || bitset(M87F_NO8TO7, flags)) && 261 !bitset(EF_TOODEEP, e->e_flags) 262 ) 263 { 264 265 if (sm_strcasecmp(subtype, "digest") == 0) 266 flags |= M87F_DIGEST; 267 268 for (i = 0; i < argc; i++) 269 { 270 if (sm_strcasecmp(argv[i].a_field, "boundary") == 0) 271 break; 272 } 273 if (i >= argc || argv[i].a_value == NULL) 274 { 275 usrerr("mime8to7: Content-Type: \"%s\": %s boundary", 276 i >= argc ? "missing" : "bogus", p); 277 p = "---"; 278 279 /* avoid bounce loops */ 280 e->e_flags |= EF_DONT_MIME; 281 } 282 else 283 { 284 p = argv[i].a_value; 285 unfoldstripquotes(p); 286 } 287 if (sm_strlcpy(bbuf, p, sizeof(bbuf)) >= sizeof(bbuf)) 288 { 289 usrerr("mime8to7: multipart boundary \"%s\" too long", 290 p); 291 292 /* avoid bounce loops */ 293 e->e_flags |= EF_DONT_MIME; 294 } 295 296 if (tTd(43, 1)) 297 sm_dprintf("mime8to7: multipart boundary \"%s\"\n", 298 bbuf); 299 for (i = 0; i < MAXMIMENESTING; i++) 300 { 301 if (boundaries[i] == NULL) 302 break; 303 } 304 if (i >= MAXMIMENESTING) 305 { 306 if (tTd(43, 4)) 307 sm_dprintf("mime8to7: too deep, i=%d\n", i); 308 if (!bitset(EF_TOODEEP, e->e_flags)) 309 usrerr("mime8to7: multipart nesting boundary too deep"); 310 311 /* avoid bounce loops */ 312 e->e_flags |= EF_DONT_MIME|EF_TOODEEP; 313 } 314 else 315 { 316 boundaries[i] = bbuf; 317 boundaries[i + 1] = NULL; 318 } 319 mci->mci_flags |= MCIF_INMIME; 320 321 /* skip the early "comment" prologue */ 322 if (!putline("", mci)) 323 goto writeerr; 324 mci->mci_flags &= ~MCIF_INHEADER; 325 bt = MBT_FINAL; 326 while ((blen = sm_io_fgets(e->e_dfp, SM_TIME_DEFAULT, buf, 327 sizeof(buf))) >= 0) 328 { 329 bt = mimeboundary(buf, boundaries); 330 if (bt != MBT_NOTSEP) 331 break; 332 if (!putxline(buf, blen, mci, 333 PXLF_MAPFROM|PXLF_STRIP8BIT)) 334 goto writeerr; 335 if (tTd(43, 99)) 336 sm_dprintf(" ...%s", buf); 337 } 338 if (sm_io_eof(e->e_dfp)) 339 bt = MBT_FINAL; 340 while (bt != MBT_FINAL) 341 { 342 auto HDR *hdr = NULL; 343 344 (void) sm_strlcpyn(buf, sizeof(buf), 2, "--", bbuf); 345 if (!putline(buf, mci)) 346 goto writeerr; 347 if (tTd(43, 35)) 348 sm_dprintf(" ...%s\n", buf); 349 collect(e->e_dfp, false, &hdr, e, false); 350 if (tTd(43, 101)) 351 putline("+++after collect", mci); 352 if (!putheader(mci, hdr, e, flags)) 353 goto writeerr; 354 if (tTd(43, 101)) 355 putline("+++after putheader", mci); 356 bt = mime8to7(mci, hdr, e, boundaries, flags, 357 level + 1); 358 if (bt == SM_IO_EOF) 359 goto writeerr; 360 } 361 (void) sm_strlcpyn(buf, sizeof(buf), 3, "--", bbuf, "--"); 362 if (!putline(buf, mci)) 363 goto writeerr; 364 if (tTd(43, 35)) 365 sm_dprintf(" ...%s\n", buf); 366 boundaries[i] = NULL; 367 mci->mci_flags &= ~MCIF_INMIME; 368 369 /* skip the late "comment" epilogue */ 370 while ((blen = sm_io_fgets(e->e_dfp, SM_TIME_DEFAULT, buf, 371 sizeof(buf))) >= 0) 372 { 373 bt = mimeboundary(buf, boundaries); 374 if (bt != MBT_NOTSEP) 375 break; 376 if (!putxline(buf, blen, mci, 377 PXLF_MAPFROM|PXLF_STRIP8BIT)) 378 goto writeerr; 379 if (tTd(43, 99)) 380 sm_dprintf(" ...%s", buf); 381 } 382 if (sm_io_eof(e->e_dfp)) 383 bt = MBT_FINAL; 384 if (tTd(43, 3)) 385 sm_dprintf("\t\t\tmime8to7=>%s (multipart)\n", 386 MimeBoundaryNames[bt]); 387 return bt; 388 } 389 390 /* 391 ** Message/xxx types -- recurse exactly once. 392 ** 393 ** Class 's' is predefined to have "rfc822" only. 394 */ 395 396 if (sm_strcasecmp(type, "message") == 0) 397 { 398 if (!wordinclass(subtype, 's') || 399 bitset(EF_TOODEEP, e->e_flags)) 400 { 401 flags |= M87F_NO8BIT; 402 } 403 else 404 { 405 auto HDR *hdr = NULL; 406 407 if (!putline("", mci)) 408 goto writeerr; 409 410 mci->mci_flags |= MCIF_INMIME; 411 collect(e->e_dfp, false, &hdr, e, false); 412 if (tTd(43, 101)) 413 putline("+++after collect", mci); 414 if (!putheader(mci, hdr, e, flags)) 415 goto writeerr; 416 if (tTd(43, 101)) 417 putline("+++after putheader", mci); 418 if (hvalue("MIME-Version", hdr) == NULL && 419 !bitset(M87F_NO8TO7, flags) && 420 !putline("MIME-Version: 1.0", mci)) 421 goto writeerr; 422 bt = mime8to7(mci, hdr, e, boundaries, flags, 423 level + 1); 424 mci->mci_flags &= ~MCIF_INMIME; 425 return bt; 426 } 427 } 428 429 /* 430 ** Non-compound body type 431 ** 432 ** Compute the ratio of seven to eight bit characters; 433 ** use that as a heuristic to decide how to do the 434 ** encoding. 435 */ 436 437 sectionsize = sectionhighbits = 0; 438 if (!bitset(M87F_NO8BIT|M87F_NO8TO7, flags)) 439 { 440 /* remember where we were */ 441 offset = sm_io_tell(e->e_dfp, SM_TIME_DEFAULT); 442 if (offset == -1) 443 syserr("mime8to7: cannot sm_io_tell on %cf%s", 444 DATAFL_LETTER, e->e_id); 445 446 /* do a scan of this body type to count character types */ 447 while ((blen = sm_io_fgets(e->e_dfp, SM_TIME_DEFAULT, buf, 448 sizeof(buf))) >= 0) 449 { 450 if (mimeboundary(buf, boundaries) != MBT_NOTSEP) 451 break; 452 for (i = 0; i < blen; i++) 453 { 454 /* count bytes with the high bit set */ 455 sectionsize++; 456 if (bitset(0200, buf[i])) 457 sectionhighbits++; 458 } 459 460 /* 461 ** Heuristic: if 1/4 of the first 4K bytes are 8-bit, 462 ** assume base64. This heuristic avoids double-reading 463 ** large graphics or video files. 464 */ 465 466 if (sectionsize >= 4096 && 467 sectionhighbits > sectionsize / 4) 468 break; 469 } 470 471 /* return to the original offset for processing */ 472 /* XXX use relative seeks to handle >31 bit file sizes? */ 473 if (sm_io_seek(e->e_dfp, SM_TIME_DEFAULT, offset, SEEK_SET) < 0) 474 syserr("mime8to7: cannot sm_io_fseek on %cf%s", 475 DATAFL_LETTER, e->e_id); 476 else 477 sm_io_clearerr(e->e_dfp); 478 } 479 480 /* 481 ** Heuristically determine encoding method. 482 ** If more than 1/8 of the total characters have the 483 ** eighth bit set, use base64; else use quoted-printable. 484 ** However, only encode binary encoded data as base64, 485 ** since otherwise the NL=>CRLF mapping will be a problem. 486 */ 487 488 if (tTd(43, 8)) 489 { 490 sm_dprintf("mime8to7: %ld high bit(s) in %ld byte(s), cte=%s, type=%s/%s\n", 491 (long) sectionhighbits, (long) sectionsize, 492 cte == NULL ? "[none]" : cte, 493 type == NULL ? "[none]" : type, 494 subtype == NULL ? "[none]" : subtype); 495 } 496 if (cte != NULL && sm_strcasecmp(cte, "binary") == 0) 497 sectionsize = sectionhighbits; 498 linelen = 0; 499 bp = buf; 500 if (sectionhighbits == 0) 501 { 502 /* no encoding necessary */ 503 if (cte != NULL && 504 bitset(MCIF_CVT8TO7|MCIF_CVT7TO8|MCIF_INMIME, 505 mci->mci_flags) && 506 !bitset(M87F_NO8TO7, flags)) 507 { 508 /* 509 ** Skip _unless_ in MIME mode and potentially 510 ** converting from 8 bit to 7 bit MIME. See 511 ** putheader() for the counterpart where the 512 ** CTE header is skipped in the opposite 513 ** situation. 514 */ 515 516 (void) sm_snprintf(buf, sizeof(buf), 517 "Content-Transfer-Encoding: %.200s", cte); 518 if (!putline(buf, mci)) 519 goto writeerr; 520 if (tTd(43, 36)) 521 sm_dprintf(" ...%s\n", buf); 522 } 523 if (!putline("", mci)) 524 goto writeerr; 525 mci->mci_flags &= ~MCIF_INHEADER; 526 while ((blen = sm_io_fgets(e->e_dfp, SM_TIME_DEFAULT, buf, 527 sizeof(buf))) >= 0) 528 { 529 if (!bitset(MCIF_INLONGLINE, mci->mci_flags)) 530 { 531 bt = mimeboundary(buf, boundaries); 532 if (bt != MBT_NOTSEP) 533 break; 534 } 535 if (!putxline(buf, blen, mci, 536 PXLF_MAPFROM|PXLF_NOADDEOL)) 537 goto writeerr; 538 } 539 if (sm_io_eof(e->e_dfp)) 540 bt = MBT_FINAL; 541 } 542 else if (!MapNLtoCRLF || 543 (sectionsize / 8 < sectionhighbits && !use_qp)) 544 { 545 /* use base64 encoding */ 546 int c1, c2; 547 548 if (tTd(43, 36)) 549 sm_dprintf(" ...Content-Transfer-Encoding: base64\n"); 550 if (!putline("Content-Transfer-Encoding: base64", mci)) 551 goto writeerr; 552 (void) sm_snprintf(buf, sizeof(buf), 553 "X-MIME-Autoconverted: from 8bit to base64 by %s id %s", 554 MyHostName, e->e_id); 555 if (!putline(buf, mci) || !putline("", mci)) 556 goto writeerr; 557 mci->mci_flags &= ~MCIF_INHEADER; 558 while ((c1 = mime_getchar_crlf(e->e_dfp, boundaries, &bt)) != 559 SM_IO_EOF) 560 { 561 if (linelen > 71) 562 { 563 *bp = '\0'; 564 if (!putline(buf, mci)) 565 goto writeerr; 566 linelen = 0; 567 bp = buf; 568 } 569 linelen += 4; 570 *bp++ = Base64Code[(c1 >> 2)]; 571 c1 = (c1 & 0x03) << 4; 572 c2 = mime_getchar_crlf(e->e_dfp, boundaries, &bt); 573 if (c2 == SM_IO_EOF) 574 { 575 *bp++ = Base64Code[c1]; 576 *bp++ = '='; 577 *bp++ = '='; 578 break; 579 } 580 c1 |= (c2 >> 4) & 0x0f; 581 *bp++ = Base64Code[c1]; 582 c1 = (c2 & 0x0f) << 2; 583 c2 = mime_getchar_crlf(e->e_dfp, boundaries, &bt); 584 if (c2 == SM_IO_EOF) 585 { 586 *bp++ = Base64Code[c1]; 587 *bp++ = '='; 588 break; 589 } 590 c1 |= (c2 >> 6) & 0x03; 591 *bp++ = Base64Code[c1]; 592 *bp++ = Base64Code[c2 & 0x3f]; 593 } 594 *bp = '\0'; 595 if (!putline(buf, mci)) 596 goto writeerr; 597 } 598 else 599 { 600 /* use quoted-printable encoding */ 601 int c1, c2; 602 int fromstate; 603 BITMAP256 badchars; 604 605 /* set up map of characters that must be mapped */ 606 clrbitmap(badchars); 607 for (c1 = 0x00; c1 < 0x20; c1++) 608 setbitn(c1, badchars); 609 clrbitn('\t', badchars); 610 for (c1 = 0x7f; c1 < 0x100; c1++) 611 setbitn(c1, badchars); 612 setbitn('=', badchars); 613 if (bitnset(M_EBCDIC, mci->mci_mailer->m_flags)) 614 for (p = "!\"#$@[\\]^`{|}~"; *p != '\0'; p++) 615 setbitn(*p, badchars); 616 617 if (tTd(43, 36)) 618 sm_dprintf(" ...Content-Transfer-Encoding: quoted-printable\n"); 619 if (!putline("Content-Transfer-Encoding: quoted-printable", 620 mci)) 621 goto writeerr; 622 (void) sm_snprintf(buf, sizeof(buf), 623 "X-MIME-Autoconverted: from 8bit to quoted-printable by %s id %s", 624 MyHostName, e->e_id); 625 if (!putline(buf, mci) || !putline("", mci)) 626 goto writeerr; 627 mci->mci_flags &= ~MCIF_INHEADER; 628 fromstate = 0; 629 c2 = '\n'; 630 while ((c1 = mime_getchar(e->e_dfp, boundaries, &bt)) != 631 SM_IO_EOF) 632 { 633 if (c1 == '\n') 634 { 635 if (c2 == ' ' || c2 == '\t') 636 { 637 *bp++ = '='; 638 *bp++ = Base16Code[(c2 >> 4) & 0x0f]; 639 *bp++ = Base16Code[c2 & 0x0f]; 640 } 641 if (buf[0] == '.' && bp == &buf[1]) 642 { 643 buf[0] = '='; 644 *bp++ = Base16Code[('.' >> 4) & 0x0f]; 645 *bp++ = Base16Code['.' & 0x0f]; 646 } 647 *bp = '\0'; 648 if (!putline(buf, mci)) 649 goto writeerr; 650 linelen = fromstate = 0; 651 bp = buf; 652 c2 = c1; 653 continue; 654 } 655 if (c2 == ' ' && linelen == 4 && fromstate == 4 && 656 bitnset(M_ESCFROM, mci->mci_mailer->m_flags)) 657 { 658 *bp++ = '='; 659 *bp++ = '2'; 660 *bp++ = '0'; 661 linelen += 3; 662 } 663 else if (c2 == ' ' || c2 == '\t') 664 { 665 *bp++ = c2; 666 linelen++; 667 } 668 if (linelen > 72 && 669 (linelen > 75 || c1 != '.' || 670 (linelen > 73 && c2 == '.'))) 671 { 672 if (linelen > 73 && c2 == '.') 673 bp--; 674 else 675 c2 = '\n'; 676 *bp++ = '='; 677 *bp = '\0'; 678 if (!putline(buf, mci)) 679 goto writeerr; 680 linelen = fromstate = 0; 681 bp = buf; 682 if (c2 == '.') 683 { 684 *bp++ = '.'; 685 linelen++; 686 } 687 } 688 if (bitnset(bitidx(c1), badchars)) 689 { 690 *bp++ = '='; 691 *bp++ = Base16Code[(c1 >> 4) & 0x0f]; 692 *bp++ = Base16Code[c1 & 0x0f]; 693 linelen += 3; 694 } 695 else if (c1 != ' ' && c1 != '\t') 696 { 697 if (linelen < 4 && c1 == "From"[linelen]) 698 fromstate++; 699 *bp++ = c1; 700 linelen++; 701 } 702 c2 = c1; 703 } 704 705 /* output any saved character */ 706 if (c2 == ' ' || c2 == '\t') 707 { 708 *bp++ = '='; 709 *bp++ = Base16Code[(c2 >> 4) & 0x0f]; 710 *bp++ = Base16Code[c2 & 0x0f]; 711 linelen += 3; 712 } 713 714 if (linelen > 0 || boundaries[0] != NULL) 715 { 716 *bp = '\0'; 717 if (!putline(buf, mci)) 718 goto writeerr; 719 } 720 721 } 722 if (tTd(43, 3)) 723 sm_dprintf("\t\t\tmime8to7=>%s (basic)\n", MimeBoundaryNames[bt]); 724 return bt; 725 726 writeerr: 727 return SM_IO_EOF; 728} 729/* 730** MIME_GETCHAR -- get a character for MIME processing 731** 732** Treats boundaries as SM_IO_EOF. 733** 734** Parameters: 735** fp -- the input file. 736** boundaries -- the current MIME boundaries. 737** btp -- if the return value is SM_IO_EOF, *btp is set to 738** the type of the boundary. 739** 740** Returns: 741** The next character in the input stream. 742*/ 743 744static int 745mime_getchar(fp, boundaries, btp) 746 register SM_FILE_T *fp; 747 char **boundaries; 748 int *btp; 749{ 750 int c; 751 static unsigned char *bp = NULL; 752 static int buflen = 0; 753 static bool atbol = true; /* at beginning of line */ 754 static int bt = MBT_SYNTAX; /* boundary type of next SM_IO_EOF */ 755 static unsigned char buf[128]; /* need not be a full line */ 756 int start = 0; /* indicates position of - in buffer */ 757 758 if (buflen == 1 && *bp == '\n') 759 { 760 /* last \n in buffer may be part of next MIME boundary */ 761 c = *bp; 762 } 763 else if (buflen > 0) 764 { 765 buflen--; 766 return *bp++; 767 } 768 else 769 c = sm_io_getc(fp, SM_TIME_DEFAULT); 770 bp = buf; 771 buflen = 0; 772 if (c == '\n') 773 { 774 /* might be part of a MIME boundary */ 775 *bp++ = c; 776 atbol = true; 777 c = sm_io_getc(fp, SM_TIME_DEFAULT); 778 if (c == '\n') 779 { 780 (void) sm_io_ungetc(fp, SM_TIME_DEFAULT, c); 781 return c; 782 } 783 start = 1; 784 } 785 if (c != SM_IO_EOF) 786 *bp++ = c; 787 else 788 bt = MBT_FINAL; 789 if (atbol && c == '-') 790 { 791 /* check for a message boundary */ 792 c = sm_io_getc(fp, SM_TIME_DEFAULT); 793 if (c != '-') 794 { 795 if (c != SM_IO_EOF) 796 *bp++ = c; 797 else 798 bt = MBT_FINAL; 799 buflen = bp - buf - 1; 800 bp = buf; 801 return *bp++; 802 } 803 804 /* got "--", now check for rest of separator */ 805 *bp++ = '-'; 806 while (bp < &buf[sizeof(buf) - 2] && 807 (c = sm_io_getc(fp, SM_TIME_DEFAULT)) != SM_IO_EOF && 808 c != '\n') 809 { 810 *bp++ = c; 811 } 812 *bp = '\0'; /* XXX simply cut off? */ 813 bt = mimeboundary((char *) &buf[start], boundaries); 814 switch (bt) 815 { 816 case MBT_FINAL: 817 case MBT_INTERMED: 818 /* we have a message boundary */ 819 buflen = 0; 820 *btp = bt; 821 return SM_IO_EOF; 822 } 823 824 if (bp < &buf[sizeof(buf) - 2] && c != SM_IO_EOF) 825 *bp++ = c; 826 } 827 828 atbol = c == '\n'; 829 buflen = bp - buf - 1; 830 if (buflen < 0) 831 { 832 *btp = bt; 833 return SM_IO_EOF; 834 } 835 bp = buf; 836 return *bp++; 837} 838/* 839** MIME_GETCHAR_CRLF -- do mime_getchar, but translate NL => CRLF 840** 841** Parameters: 842** fp -- the input file. 843** boundaries -- the current MIME boundaries. 844** btp -- if the return value is SM_IO_EOF, *btp is set to 845** the type of the boundary. 846** 847** Returns: 848** The next character in the input stream. 849*/ 850 851static int 852mime_getchar_crlf(fp, boundaries, btp) 853 register SM_FILE_T *fp; 854 char **boundaries; 855 int *btp; 856{ 857 static bool sendlf = false; 858 int c; 859 860 if (sendlf) 861 { 862 sendlf = false; 863 return '\n'; 864 } 865 c = mime_getchar(fp, boundaries, btp); 866 if (c == '\n' && MapNLtoCRLF) 867 { 868 sendlf = true; 869 return '\r'; 870 } 871 return c; 872} 873/* 874** MIMEBOUNDARY -- determine if this line is a MIME boundary & its type 875** 876** Parameters: 877** line -- the input line. 878** boundaries -- the set of currently pending boundaries. 879** 880** Returns: 881** MBT_NOTSEP -- if this is not a separator line 882** MBT_INTERMED -- if this is an intermediate separator 883** MBT_FINAL -- if this is a final boundary 884** MBT_SYNTAX -- if this is a boundary for the wrong 885** enclosure -- i.e., a syntax error. 886*/ 887 888static int 889mimeboundary(line, boundaries) 890 register char *line; 891 char **boundaries; 892{ 893 int type = MBT_NOTSEP; 894 int i; 895 int savec; 896 897 if (line[0] != '-' || line[1] != '-' || boundaries == NULL) 898 return MBT_NOTSEP; 899 i = strlen(line); 900 if (i > 0 && line[i - 1] == '\n') 901 i--; 902 903 /* strip off trailing whitespace */ 904 while (i > 0 && (line[i - 1] == ' ' || line[i - 1] == '\t' 905#if _FFR_MIME_CR_OK 906 || line[i - 1] == '\r' 907#endif 908 )) 909 i--; 910 savec = line[i]; 911 line[i] = '\0'; 912 913 if (tTd(43, 5)) 914 sm_dprintf("mimeboundary: line=\"%s\"... ", line); 915 916 /* check for this as an intermediate boundary */ 917 if (isboundary(&line[2], boundaries) >= 0) 918 type = MBT_INTERMED; 919 else if (i > 2 && strncmp(&line[i - 2], "--", 2) == 0) 920 { 921 /* check for a final boundary */ 922 line[i - 2] = '\0'; 923 if (isboundary(&line[2], boundaries) >= 0) 924 type = MBT_FINAL; 925 line[i - 2] = '-'; 926 } 927 928 line[i] = savec; 929 if (tTd(43, 5)) 930 sm_dprintf("%s\n", MimeBoundaryNames[type]); 931 return type; 932} 933/* 934** DEFCHARSET -- return default character set for message 935** 936** The first choice for character set is for the mailer 937** corresponding to the envelope sender. If neither that 938** nor the global configuration file has a default character 939** set defined, return "unknown-8bit" as recommended by 940** RFC 1428 section 3. 941** 942** Parameters: 943** e -- the envelope for this message. 944** 945** Returns: 946** The default character set for that mailer. 947*/ 948 949char * 950defcharset(e) 951 register ENVELOPE *e; 952{ 953 if (e != NULL && e->e_from.q_mailer != NULL && 954 e->e_from.q_mailer->m_defcharset != NULL) 955 return e->e_from.q_mailer->m_defcharset; 956 if (DefaultCharSet != NULL) 957 return DefaultCharSet; 958 return "unknown-8bit"; 959} 960/* 961** ISBOUNDARY -- is a given string a currently valid boundary? 962** 963** Parameters: 964** line -- the current input line. 965** boundaries -- the list of valid boundaries. 966** 967** Returns: 968** The index number in boundaries if the line is found. 969** -1 -- otherwise. 970** 971*/ 972 973static int 974isboundary(line, boundaries) 975 char *line; 976 char **boundaries; 977{ 978 register int i; 979 980 for (i = 0; i <= MAXMIMENESTING && boundaries[i] != NULL; i++) 981 { 982 if (strcmp(line, boundaries[i]) == 0) 983 return i; 984 } 985 return -1; 986} 987#endif /* MIME8TO7 */ 988 989#if MIME7TO8 990static int mime_fromqp __P((unsigned char *, unsigned char **, int)); 991 992/* 993** MIME7TO8 -- output 7 bit encoded MIME body in 8 bit format 994** 995** This is a hack. Supports translating the two 7-bit body-encodings 996** (quoted-printable and base64) to 8-bit coded bodies. 997** 998** There is not much point in supporting multipart here, as the UA 999** will be able to deal with encoded MIME bodies if it can parse MIME 1000** multipart messages. 1001** 1002** Note also that we won't be called unless it is a text/plain MIME 1003** message, encoded base64 or QP and mailer flag '9' has been defined 1004** on mailer. 1005** 1006** Contributed by Marius Olaffson <marius@rhi.hi.is>. 1007** 1008** Parameters: 1009** mci -- mailer connection information. 1010** header -- the header for this body part. 1011** e -- envelope. 1012** 1013** Returns: 1014** true iff body was written successfully 1015*/ 1016 1017static char index_64[128] = 1018{ 1019 -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, 1020 -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, 1021 -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63, 1022 52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1,-1,-1,-1, 1023 -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11,12,13,14, 1024 15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1, 1025 -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40, 1026 41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1 1027}; 1028 1029# define CHAR64(c) (((c) < 0 || (c) > 127) ? -1 : index_64[(c)]) 1030 1031bool 1032mime7to8(mci, header, e) 1033 register MCI *mci; 1034 HDR *header; 1035 register ENVELOPE *e; 1036{ 1037 int pxflags, blen; 1038 register char *p; 1039 char *cte; 1040 char **pvp; 1041 unsigned char *fbufp; 1042 char buf[MAXLINE]; 1043 unsigned char fbuf[MAXLINE + 1]; 1044 char pvpbuf[MAXLINE]; 1045 extern unsigned char MimeTokenTab[256]; 1046 1047 p = hvalue("Content-Transfer-Encoding", header); 1048 if (p == NULL || 1049 (pvp = prescan(p, '\0', pvpbuf, sizeof(pvpbuf), NULL, 1050 MimeTokenTab, false)) == NULL || 1051 pvp[0] == NULL) 1052 { 1053 /* "can't happen" -- upper level should have caught this */ 1054 syserr("mime7to8: unparsable CTE %s", p == NULL ? "<NULL>" : p); 1055 1056 /* avoid bounce loops */ 1057 e->e_flags |= EF_DONT_MIME; 1058 1059 /* cheap failsafe algorithm -- should work on text/plain */ 1060 if (p != NULL) 1061 { 1062 (void) sm_snprintf(buf, sizeof(buf), 1063 "Content-Transfer-Encoding: %s", p); 1064 if (!putline(buf, mci)) 1065 goto writeerr; 1066 } 1067 if (!putline("", mci)) 1068 goto writeerr; 1069 mci->mci_flags &= ~MCIF_INHEADER; 1070 while ((blen = sm_io_fgets(e->e_dfp, SM_TIME_DEFAULT, buf, 1071 sizeof(buf))) >= 0) 1072 { 1073 if (!putxline(buf, blen, mci, PXLF_MAPFROM)) 1074 goto writeerr; 1075 } 1076 return true; 1077 } 1078 cataddr(pvp, NULL, buf, sizeof(buf), '\0', false); 1079 cte = sm_rpool_strdup_x(e->e_rpool, buf); 1080 1081 mci->mci_flags |= MCIF_INHEADER; 1082 if (!putline("Content-Transfer-Encoding: 8bit", mci)) 1083 goto writeerr; 1084 (void) sm_snprintf(buf, sizeof(buf), 1085 "X-MIME-Autoconverted: from %.200s to 8bit by %s id %s", 1086 cte, MyHostName, e->e_id); 1087 if (!putline(buf, mci) || !putline("", mci)) 1088 goto writeerr; 1089 mci->mci_flags &= ~MCIF_INHEADER; 1090 1091 /* 1092 ** Translate body encoding to 8-bit. Supports two types of 1093 ** encodings; "base64" and "quoted-printable". Assume qp if 1094 ** it is not base64. 1095 */ 1096 1097 pxflags = PXLF_MAPFROM; 1098 if (sm_strcasecmp(cte, "base64") == 0) 1099 { 1100 int c1, c2, c3, c4; 1101 1102 fbufp = fbuf; 1103 while ((c1 = sm_io_getc(e->e_dfp, SM_TIME_DEFAULT)) != 1104 SM_IO_EOF) 1105 { 1106 if (SM_ISSPACE(c1)) 1107 continue; 1108 1109 do 1110 { 1111 c2 = sm_io_getc(e->e_dfp, SM_TIME_DEFAULT); 1112 } while (SM_ISSPACE(c2)); 1113 if (c2 == SM_IO_EOF) 1114 break; 1115 1116 do 1117 { 1118 c3 = sm_io_getc(e->e_dfp, SM_TIME_DEFAULT); 1119 } while (SM_ISSPACE(c3)); 1120 if (c3 == SM_IO_EOF) 1121 break; 1122 1123 do 1124 { 1125 c4 = sm_io_getc(e->e_dfp, SM_TIME_DEFAULT); 1126 } while (SM_ISSPACE(c4)); 1127 if (c4 == SM_IO_EOF) 1128 break; 1129 1130 if (c1 == '=' || c2 == '=') 1131 continue; 1132 c1 = CHAR64(c1); 1133 c2 = CHAR64(c2); 1134 1135#if MIME7TO8_OLD 1136#define CHK_EOL if (*--fbufp != '\n' || (fbufp > fbuf && *--fbufp != '\r')) \ 1137 ++fbufp; 1138#else /* MIME7TO8_OLD */ 1139#define CHK_EOL if (*--fbufp != '\n' || (fbufp > fbuf && *--fbufp != '\r')) \ 1140 { \ 1141 ++fbufp; \ 1142 pxflags |= PXLF_NOADDEOL; \ 1143 } 1144#endif /* MIME7TO8_OLD */ 1145 1146#define PUTLINE64 \ 1147 do \ 1148 { \ 1149 if (*fbufp++ == '\n' || fbufp >= &fbuf[MAXLINE]) \ 1150 { \ 1151 CHK_EOL; \ 1152 if (!putxline((char *) fbuf, fbufp - fbuf, mci, pxflags)) \ 1153 goto writeerr; \ 1154 pxflags &= ~PXLF_NOADDEOL; \ 1155 fbufp = fbuf; \ 1156 } \ 1157 } while (0) 1158 1159 *fbufp = (c1 << 2) | ((c2 & 0x30) >> 4); 1160 PUTLINE64; 1161 if (c3 == '=') 1162 continue; 1163 c3 = CHAR64(c3); 1164 *fbufp = ((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2); 1165 PUTLINE64; 1166 if (c4 == '=') 1167 continue; 1168 c4 = CHAR64(c4); 1169 *fbufp = ((c3 & 0x03) << 6) | c4; 1170 PUTLINE64; 1171 } 1172 } 1173 else 1174 { 1175 int off; 1176 1177 /* quoted-printable */ 1178 pxflags |= PXLF_NOADDEOL; 1179 fbufp = fbuf; 1180 while (sm_io_fgets(e->e_dfp, SM_TIME_DEFAULT, buf, 1181 sizeof(buf)) >= 0) 1182 { 1183 off = mime_fromqp((unsigned char *) buf, &fbufp, 1184 &fbuf[MAXLINE] - fbufp); 1185again: 1186 if (off < -1) 1187 continue; 1188 1189 if (fbufp - fbuf > 0) 1190 { 1191 if (!putxline((char *) fbuf, fbufp - fbuf - 1, 1192 mci, pxflags)) 1193 goto writeerr; 1194 } 1195 fbufp = fbuf; 1196 if (off >= 0 && buf[off] != '\0') 1197 { 1198 off = mime_fromqp((unsigned char *) (buf + off), 1199 &fbufp, 1200 &fbuf[MAXLINE] - fbufp); 1201 goto again; 1202 } 1203 } 1204 } 1205 1206 /* force out partial last line */ 1207 if (fbufp > fbuf) 1208 { 1209 *fbufp = '\0'; 1210 if (!putxline((char *) fbuf, fbufp - fbuf, mci, pxflags)) 1211 goto writeerr; 1212 } 1213 1214 /* 1215 ** The decoded text may end without an EOL. Since this function 1216 ** is only called for text/plain MIME messages, it is safe to 1217 ** add an extra one at the end just in case. This is a hack, 1218 ** but so is auto-converting MIME in the first place. 1219 */ 1220 1221 if (!putline("", mci)) 1222 goto writeerr; 1223 1224 if (tTd(43, 3)) 1225 sm_dprintf("\t\t\tmime7to8 => %s to 8bit done\n", cte); 1226 return true; 1227 1228 writeerr: 1229 return false; 1230} 1231/* 1232** The following is based on Borenstein's "codes.c" module, with simplifying 1233** changes as we do not deal with multipart, and to do the translation in-core, 1234** with an attempt to prevent overrun of output buffers. 1235** 1236** What is needed here are changes to defend this code better against 1237** bad encodings. Questionable to always return 0xFF for bad mappings. 1238*/ 1239 1240static char index_hex[128] = 1241{ 1242 -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, 1243 -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, 1244 -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, 1245 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,-1,-1, -1,-1,-1,-1, 1246 -1,10,11,12, 13,14,15,-1, -1,-1,-1,-1, -1,-1,-1,-1, 1247 -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, 1248 -1,10,11,12, 13,14,15,-1, -1,-1,-1,-1, -1,-1,-1,-1, 1249 -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1 1250}; 1251 1252# define HEXCHAR(c) (((c) < 0 || (c) > 127) ? -1 : index_hex[(c)]) 1253 1254/* 1255** MIME_FROMQP -- decode quoted printable string 1256** 1257** Parameters: 1258** infile -- input (encoded) string 1259** outfile -- output string 1260** maxlen -- size of output buffer 1261** 1262** Returns: 1263** -2 if decoding failure 1264** -1 if infile completely decoded into outfile 1265** >= 0 is the position in infile decoding 1266** reached before maxlen was reached 1267*/ 1268 1269static int 1270mime_fromqp(infile, outfile, maxlen) 1271 unsigned char *infile; 1272 unsigned char **outfile; 1273 int maxlen; /* Max # of chars allowed in outfile */ 1274{ 1275 int c1, c2; 1276 int nchar = 0; 1277 unsigned char *b; 1278 1279 /* decrement by one for trailing '\0', at least one other char */ 1280 if (--maxlen < 1) 1281 return 0; 1282 1283 b = infile; 1284 while ((c1 = *infile++) != '\0' && nchar < maxlen) 1285 { 1286 if (c1 == '=') 1287 { 1288 if ((c1 = *infile++) == '\0') 1289 break; 1290 1291 if (c1 == '\n' || (c1 = HEXCHAR(c1)) == -1) 1292 { 1293 /* ignore it and the rest of the buffer */ 1294 return -2; 1295 } 1296 else 1297 { 1298 do 1299 { 1300 if ((c2 = *infile++) == '\0') 1301 { 1302 c2 = -1; 1303 break; 1304 } 1305 } while ((c2 = HEXCHAR(c2)) == -1); 1306 1307 if (c2 == -1) 1308 break; 1309 nchar++; 1310 *(*outfile)++ = c1 << 4 | c2; 1311 } 1312 } 1313 else 1314 { 1315 nchar++; 1316 *(*outfile)++ = c1; 1317 if (c1 == '\n') 1318 break; 1319 } 1320 } 1321 *(*outfile)++ = '\0'; 1322 if (nchar >= maxlen) 1323 return (infile - b - 1); 1324 return -1; 1325} 1326#endif /* MIME7TO8 */ 1327