1/* $OpenBSD: asn_mime.c,v 1.34 2024/03/29 04:35:42 tb Exp $ */ 2/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL 3 * project. 4 */ 5/* ==================================================================== 6 * Copyright (c) 1999-2008 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing@OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 */ 54 55#include <ctype.h> 56#include <stdio.h> 57#include <stdlib.h> 58#include <string.h> 59 60#include <openssl/asn1.h> 61#include <openssl/asn1t.h> 62#include <openssl/err.h> 63#include <openssl/x509.h> 64 65#include "asn1_local.h" 66#include "evp_local.h" 67 68/* Generalised MIME like utilities for streaming ASN1. Although many 69 * have a PKCS7/CMS like flavour others are more general purpose. 70 */ 71 72/* MIME format structures 73 * Note that all are translated to lower case apart from 74 * parameter values. Quotes are stripped off 75 */ 76 77typedef struct { 78 char *param_name; /* Param name e.g. "micalg" */ 79 char *param_value; /* Param value e.g. "sha1" */ 80} MIME_PARAM; 81 82DECLARE_STACK_OF(MIME_PARAM) 83 84typedef struct { 85 char *name; /* Name of line e.g. "content-type" */ 86 char *value; /* Value of line e.g. "text/plain" */ 87 STACK_OF(MIME_PARAM) *params; /* Zero or more parameters */ 88} MIME_HEADER; 89 90DECLARE_STACK_OF(MIME_HEADER) 91 92static int asn1_output_data(BIO *out, BIO *data, ASN1_VALUE *val, int flags, 93 const ASN1_ITEM *it); 94static char * strip_ends(char *name); 95static char * strip_start(char *name); 96static char * strip_end(char *name); 97static MIME_HEADER *mime_hdr_new(char *name, char *value); 98static int mime_hdr_addparam(MIME_HEADER *mhdr, char *name, char *value); 99static STACK_OF(MIME_HEADER) *mime_parse_hdr(BIO *bio); 100static int mime_hdr_cmp(const MIME_HEADER * const *a, 101 const MIME_HEADER * const *b); 102static int mime_param_cmp(const MIME_PARAM * const *a, 103 const MIME_PARAM * const *b); 104static void mime_param_free(MIME_PARAM *param); 105static int mime_bound_check(char *line, int linelen, char *bound, int blen); 106static int multi_split(BIO *bio, char *bound, STACK_OF(BIO) **ret); 107static int strip_eol(char *linebuf, int *plen); 108static MIME_HEADER *mime_hdr_find(STACK_OF(MIME_HEADER) *hdrs, char *name); 109static MIME_PARAM *mime_param_find(MIME_HEADER *hdr, char *name); 110static void mime_hdr_free(MIME_HEADER *hdr); 111 112#define MAX_SMLEN 1024 113 114/* Output an ASN1 structure in BER format streaming if necessary */ 115 116int 117i2d_ASN1_bio_stream(BIO *out, ASN1_VALUE *val, BIO *in, int flags, 118 const ASN1_ITEM *it) 119{ 120 BIO *bio, *tbio; 121 int ret; 122 123 /* Without streaming, write out the ASN.1 structure's content. */ 124 if ((flags & SMIME_STREAM) == 0) 125 return ASN1_item_i2d_bio(it, out, val); 126 127 /* If streaming, create a stream BIO and copy all content through it. */ 128 if ((bio = BIO_new_NDEF(out, val, it)) == NULL) { 129 ASN1error(ERR_R_MALLOC_FAILURE); 130 return 0; 131 } 132 133 ret = SMIME_crlf_copy(in, bio, flags); 134 (void)BIO_flush(bio); 135 136 /* Free up successive BIOs until we hit the old output BIO. */ 137 do { 138 tbio = BIO_pop(bio); 139 BIO_free(bio); 140 bio = tbio; 141 } while (bio != out); 142 143 return ret; 144} 145 146/* Base 64 read and write of ASN1 structure */ 147 148static int 149B64_write_ASN1(BIO *out, ASN1_VALUE *val, BIO *in, int flags, 150 const ASN1_ITEM *it) 151{ 152 BIO *b64; 153 int r; 154 155 b64 = BIO_new(BIO_f_base64()); 156 if (!b64) { 157 ASN1error(ERR_R_MALLOC_FAILURE); 158 return 0; 159 } 160 /* prepend the b64 BIO so all data is base64 encoded. 161 */ 162 out = BIO_push(b64, out); 163 r = i2d_ASN1_bio_stream(out, val, in, flags, it); 164 (void)BIO_flush(out); 165 BIO_pop(out); 166 BIO_free(b64); 167 return r; 168} 169 170/* Streaming ASN1 PEM write */ 171 172int 173PEM_write_bio_ASN1_stream(BIO *out, ASN1_VALUE *val, BIO *in, int flags, 174 const char *hdr, const ASN1_ITEM *it) 175{ 176 int r; 177 178 BIO_printf(out, "-----BEGIN %s-----\n", hdr); 179 r = B64_write_ASN1(out, val, in, flags, it); 180 BIO_printf(out, "-----END %s-----\n", hdr); 181 return r; 182} 183 184static ASN1_VALUE * 185b64_read_asn1(BIO *bio, const ASN1_ITEM *it) 186{ 187 BIO *b64; 188 ASN1_VALUE *val; 189 if (!(b64 = BIO_new(BIO_f_base64()))) { 190 ASN1error(ERR_R_MALLOC_FAILURE); 191 return 0; 192 } 193 bio = BIO_push(b64, bio); 194 val = ASN1_item_d2i_bio(it, bio, NULL); 195 if (!val) 196 ASN1error(ASN1_R_DECODE_ERROR); 197 (void)BIO_flush(bio); 198 bio = BIO_pop(bio); 199 BIO_free(b64); 200 return val; 201} 202 203/* Generate the MIME "micalg" parameter from RFC3851, RFC4490 */ 204 205static int 206asn1_write_micalg(BIO *out, STACK_OF(X509_ALGOR) *mdalgs) 207{ 208 const EVP_MD *md; 209 int i, have_unknown = 0, write_comma, ret = 0, md_nid; 210 211 have_unknown = 0; 212 write_comma = 0; 213 for (i = 0; i < sk_X509_ALGOR_num(mdalgs); i++) { 214 if (write_comma) 215 BIO_write(out, ",", 1); 216 write_comma = 1; 217 md_nid = OBJ_obj2nid(sk_X509_ALGOR_value(mdalgs, i)->algorithm); 218 md = EVP_get_digestbynid(md_nid); 219 if (md && md->md_ctrl) { 220 int rv; 221 char *micstr; 222 rv = md->md_ctrl(NULL, EVP_MD_CTRL_MICALG, 0, &micstr); 223 if (rv > 0) { 224 BIO_puts(out, micstr); 225 free(micstr); 226 continue; 227 } 228 if (rv != -2) 229 goto err; 230 } 231 switch (md_nid) { 232 case NID_sha1: 233 BIO_puts(out, "sha1"); 234 break; 235 236 case NID_md5: 237 BIO_puts(out, "md5"); 238 break; 239 240 case NID_sha256: 241 BIO_puts(out, "sha-256"); 242 break; 243 244 case NID_sha384: 245 BIO_puts(out, "sha-384"); 246 break; 247 248 case NID_sha512: 249 BIO_puts(out, "sha-512"); 250 break; 251 252 case NID_id_GostR3411_94: 253 BIO_puts(out, "gostr3411-94"); 254 goto err; 255 break; 256 257 default: 258 if (have_unknown) 259 write_comma = 0; 260 else { 261 BIO_puts(out, "unknown"); 262 have_unknown = 1; 263 } 264 break; 265 266 } 267 } 268 269 ret = 1; 270 271 err: 272 return ret; 273} 274 275/* SMIME sender */ 276 277int 278SMIME_write_ASN1(BIO *bio, ASN1_VALUE *val, BIO *data, int flags, 279 int ctype_nid, int econt_nid, STACK_OF(X509_ALGOR) *mdalgs, 280 const ASN1_ITEM *it) 281{ 282 char bound[33], c; 283 int i; 284 const char *mime_prefix, *mime_eol, *cname = "smime.p7m"; 285 const char *msg_type = NULL; 286 287 if (flags & SMIME_OLDMIME) 288 mime_prefix = "application/x-pkcs7-"; 289 else 290 mime_prefix = "application/pkcs7-"; 291 292 if (flags & SMIME_CRLFEOL) 293 mime_eol = "\r\n"; 294 else 295 mime_eol = "\n"; 296 if ((flags & SMIME_DETACHED) && data) { 297 /* We want multipart/signed */ 298 /* Generate a random boundary */ 299 arc4random_buf(bound, 32); 300 for (i = 0; i < 32; i++) { 301 c = bound[i] & 0xf; 302 if (c < 10) 303 c += '0'; 304 else 305 c += 'A' - 10; 306 bound[i] = c; 307 } 308 bound[32] = 0; 309 BIO_printf(bio, "MIME-Version: 1.0%s", mime_eol); 310 BIO_printf(bio, "Content-Type: multipart/signed;"); 311 BIO_printf(bio, " protocol=\"%ssignature\";", mime_prefix); 312 BIO_puts(bio, " micalg=\""); 313 asn1_write_micalg(bio, mdalgs); 314 BIO_printf(bio, "\"; boundary=\"----%s\"%s%s", 315 bound, mime_eol, mime_eol); 316 BIO_printf(bio, "This is an S/MIME signed message%s%s", 317 mime_eol, mime_eol); 318 /* Now write out the first part */ 319 BIO_printf(bio, "------%s%s", bound, mime_eol); 320 if (!asn1_output_data(bio, data, val, flags, it)) 321 return 0; 322 BIO_printf(bio, "%s------%s%s", mime_eol, bound, mime_eol); 323 324 /* Headers for signature */ 325 326 BIO_printf(bio, "Content-Type: %ssignature;", mime_prefix); 327 BIO_printf(bio, " name=\"smime.p7s\"%s", mime_eol); 328 BIO_printf(bio, "Content-Transfer-Encoding: base64%s", 329 mime_eol); 330 BIO_printf(bio, "Content-Disposition: attachment;"); 331 BIO_printf(bio, " filename=\"smime.p7s\"%s%s", 332 mime_eol, mime_eol); 333 B64_write_ASN1(bio, val, NULL, 0, it); 334 BIO_printf(bio, "%s------%s--%s%s", mime_eol, bound, 335 mime_eol, mime_eol); 336 return 1; 337 } 338 339 /* Determine smime-type header */ 340 341 if (ctype_nid == NID_pkcs7_enveloped) 342 msg_type = "enveloped-data"; 343 else if (ctype_nid == NID_pkcs7_signed) { 344 if (econt_nid == NID_id_smime_ct_receipt) 345 msg_type = "signed-receipt"; 346 else if (sk_X509_ALGOR_num(mdalgs) >= 0) 347 msg_type = "signed-data"; 348 else 349 msg_type = "certs-only"; 350 } else if (ctype_nid == NID_id_smime_ct_compressedData) { 351 msg_type = "compressed-data"; 352 cname = "smime.p7z"; 353 } 354 /* MIME headers */ 355 BIO_printf(bio, "MIME-Version: 1.0%s", mime_eol); 356 BIO_printf(bio, "Content-Disposition: attachment;"); 357 BIO_printf(bio, " filename=\"%s\"%s", cname, mime_eol); 358 BIO_printf(bio, "Content-Type: %smime;", mime_prefix); 359 if (msg_type) 360 BIO_printf(bio, " smime-type=%s;", msg_type); 361 BIO_printf(bio, " name=\"%s\"%s", cname, mime_eol); 362 BIO_printf(bio, "Content-Transfer-Encoding: base64%s%s", 363 mime_eol, mime_eol); 364 if (!B64_write_ASN1(bio, val, data, flags, it)) 365 return 0; 366 BIO_printf(bio, "%s", mime_eol); 367 return 1; 368} 369 370/* Handle output of ASN1 data */ 371 372 373static int 374asn1_output_data(BIO *out, BIO *data, ASN1_VALUE *val, int flags, 375 const ASN1_ITEM *it) 376{ 377 BIO *tmpbio; 378 const ASN1_AUX *aux = it->funcs; 379 ASN1_STREAM_ARG sarg; 380 int rv = 1; 381 382 /* If data is not deteched or resigning then the output BIO is 383 * already set up to finalise when it is written through. 384 */ 385 if (!(flags & SMIME_DETACHED) || (flags & PKCS7_REUSE_DIGEST)) { 386 SMIME_crlf_copy(data, out, flags); 387 return 1; 388 } 389 390 if (!aux || !aux->asn1_cb) { 391 ASN1error(ASN1_R_STREAMING_NOT_SUPPORTED); 392 return 0; 393 } 394 395 sarg.out = out; 396 sarg.ndef_bio = NULL; 397 sarg.boundary = NULL; 398 399 /* Let ASN1 code prepend any needed BIOs */ 400 401 if (aux->asn1_cb(ASN1_OP_DETACHED_PRE, &val, it, &sarg) <= 0) 402 return 0; 403 404 /* Copy data across, passing through filter BIOs for processing */ 405 SMIME_crlf_copy(data, sarg.ndef_bio, flags); 406 407 /* Finalize structure */ 408 if (aux->asn1_cb(ASN1_OP_DETACHED_POST, &val, it, &sarg) <= 0) 409 rv = 0; 410 411 /* Now remove any digests prepended to the BIO */ 412 413 while (sarg.ndef_bio != out) { 414 tmpbio = BIO_pop(sarg.ndef_bio); 415 BIO_free(sarg.ndef_bio); 416 sarg.ndef_bio = tmpbio; 417 } 418 419 return rv; 420} 421 422/* SMIME reader: handle multipart/signed and opaque signing. 423 * in multipart case the content is placed in a memory BIO 424 * pointed to by "bcont". In opaque this is set to NULL 425 */ 426 427ASN1_VALUE * 428SMIME_read_ASN1(BIO *bio, BIO **bcont, const ASN1_ITEM *it) 429{ 430 BIO *asnin; 431 STACK_OF(MIME_HEADER) *headers = NULL; 432 STACK_OF(BIO) *parts = NULL; 433 MIME_HEADER *hdr; 434 MIME_PARAM *prm; 435 ASN1_VALUE *val; 436 int ret; 437 438 if (bcont) 439 *bcont = NULL; 440 441 if (!(headers = mime_parse_hdr(bio))) { 442 ASN1error(ASN1_R_MIME_PARSE_ERROR); 443 return NULL; 444 } 445 446 if (!(hdr = mime_hdr_find(headers, "content-type")) || !hdr->value) { 447 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 448 ASN1error(ASN1_R_NO_CONTENT_TYPE); 449 return NULL; 450 } 451 452 /* Handle multipart/signed */ 453 454 if (!strcmp(hdr->value, "multipart/signed")) { 455 /* Split into two parts */ 456 prm = mime_param_find(hdr, "boundary"); 457 if (!prm || !prm->param_value) { 458 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 459 ASN1error(ASN1_R_NO_MULTIPART_BOUNDARY); 460 return NULL; 461 } 462 ret = multi_split(bio, prm->param_value, &parts); 463 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 464 if (!ret || (sk_BIO_num(parts) != 2) ) { 465 ASN1error(ASN1_R_NO_MULTIPART_BODY_FAILURE); 466 sk_BIO_pop_free(parts, BIO_vfree); 467 return NULL; 468 } 469 470 /* Parse the signature piece */ 471 asnin = sk_BIO_value(parts, 1); 472 473 if (!(headers = mime_parse_hdr(asnin))) { 474 ASN1error(ASN1_R_MIME_SIG_PARSE_ERROR); 475 sk_BIO_pop_free(parts, BIO_vfree); 476 return NULL; 477 } 478 479 /* Get content type */ 480 481 if (!(hdr = mime_hdr_find(headers, "content-type")) || 482 !hdr->value) { 483 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 484 sk_BIO_pop_free(parts, BIO_vfree); 485 ASN1error(ASN1_R_NO_SIG_CONTENT_TYPE); 486 return NULL; 487 } 488 489 if (strcmp(hdr->value, "application/x-pkcs7-signature") && 490 strcmp(hdr->value, "application/pkcs7-signature")) { 491 ASN1error(ASN1_R_SIG_INVALID_MIME_TYPE); 492 ERR_asprintf_error_data("type: %s", hdr->value); 493 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 494 sk_BIO_pop_free(parts, BIO_vfree); 495 return NULL; 496 } 497 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 498 /* Read in ASN1 */ 499 if (!(val = b64_read_asn1(asnin, it))) { 500 ASN1error(ASN1_R_ASN1_SIG_PARSE_ERROR); 501 sk_BIO_pop_free(parts, BIO_vfree); 502 return NULL; 503 } 504 505 if (bcont) { 506 *bcont = sk_BIO_value(parts, 0); 507 BIO_free(asnin); 508 sk_BIO_free(parts); 509 } else sk_BIO_pop_free(parts, BIO_vfree); 510 return val; 511 } 512 513 /* OK, if not multipart/signed try opaque signature */ 514 515 if (strcmp (hdr->value, "application/x-pkcs7-mime") && 516 strcmp (hdr->value, "application/pkcs7-mime")) { 517 ASN1error(ASN1_R_INVALID_MIME_TYPE); 518 ERR_asprintf_error_data("type: %s", hdr->value); 519 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 520 return NULL; 521 } 522 523 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 524 525 if (!(val = b64_read_asn1(bio, it))) { 526 ASN1error(ASN1_R_ASN1_PARSE_ERROR); 527 return NULL; 528 } 529 return val; 530} 531 532/* Copy text from one BIO to another making the output CRLF at EOL */ 533int 534SMIME_crlf_copy(BIO *in, BIO *out, int flags) 535{ 536 BIO *bf; 537 char eol; 538 int len; 539 char linebuf[MAX_SMLEN]; 540 541 /* Buffer output so we don't write one line at a time. This is 542 * useful when streaming as we don't end up with one OCTET STRING 543 * per line. 544 */ 545 bf = BIO_new(BIO_f_buffer()); 546 if (!bf) 547 return 0; 548 out = BIO_push(bf, out); 549 if (flags & SMIME_BINARY) { 550 while ((len = BIO_read(in, linebuf, MAX_SMLEN)) > 0) 551 BIO_write(out, linebuf, len); 552 } else { 553 if (flags & SMIME_TEXT) 554 BIO_printf(out, "Content-Type: text/plain\r\n\r\n"); 555 while ((len = BIO_gets(in, linebuf, MAX_SMLEN)) > 0) { 556 eol = strip_eol(linebuf, &len); 557 if (len) 558 BIO_write(out, linebuf, len); 559 if (eol) 560 BIO_write(out, "\r\n", 2); 561 } 562 } 563 (void)BIO_flush(out); 564 BIO_pop(out); 565 BIO_free(bf); 566 return 1; 567} 568LCRYPTO_ALIAS(SMIME_crlf_copy); 569 570/* Strip off headers if they are text/plain */ 571int 572SMIME_text(BIO *in, BIO *out) 573{ 574 char iobuf[4096]; 575 int len; 576 STACK_OF(MIME_HEADER) *headers; 577 MIME_HEADER *hdr; 578 579 if (!(headers = mime_parse_hdr(in))) { 580 ASN1error(ASN1_R_MIME_PARSE_ERROR); 581 return 0; 582 } 583 if (!(hdr = mime_hdr_find(headers, "content-type")) || !hdr->value) { 584 ASN1error(ASN1_R_MIME_NO_CONTENT_TYPE); 585 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 586 return 0; 587 } 588 if (strcmp (hdr->value, "text/plain")) { 589 ASN1error(ASN1_R_INVALID_MIME_TYPE); 590 ERR_asprintf_error_data("type: %s", hdr->value); 591 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 592 return 0; 593 } 594 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 595 while ((len = BIO_read(in, iobuf, sizeof(iobuf))) > 0) 596 BIO_write(out, iobuf, len); 597 if (len < 0) 598 return 0; 599 return 1; 600} 601LCRYPTO_ALIAS(SMIME_text); 602 603/* 604 * Split a multipart/XXX message body into component parts: result is 605 * canonical parts in a STACK of bios 606 */ 607static int 608multi_split(BIO *bio, char *bound, STACK_OF(BIO) **ret) 609{ 610 char linebuf[MAX_SMLEN]; 611 int len, blen; 612 int eol = 0, next_eol = 0; 613 BIO *bpart = NULL; 614 STACK_OF(BIO) *parts; 615 char state, part, first; 616 617 blen = strlen(bound); 618 part = 0; 619 state = 0; 620 first = 1; 621 parts = sk_BIO_new_null(); 622 *ret = parts; 623 if (parts == NULL) 624 return 0; 625 while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) { 626 state = mime_bound_check(linebuf, len, bound, blen); 627 if (state == 1) { 628 first = 1; 629 part++; 630 } else if (state == 2) { 631 if (sk_BIO_push(parts, bpart) == 0) 632 return 0; 633 return 1; 634 } else if (part) { 635 /* Strip CR+LF from linebuf */ 636 next_eol = strip_eol(linebuf, &len); 637 if (first) { 638 first = 0; 639 if (bpart != NULL) { 640 if (sk_BIO_push(parts, bpart) == 0) 641 return 0; 642 } 643 bpart = BIO_new(BIO_s_mem()); 644 if (bpart == NULL) 645 return 0; 646 BIO_set_mem_eof_return(bpart, 0); 647 } else if (eol) 648 BIO_write(bpart, "\r\n", 2); 649 eol = next_eol; 650 if (len) 651 BIO_write(bpart, linebuf, len); 652 } 653 } 654 BIO_free(bpart); 655 return 0; 656} 657 658/* This is the big one: parse MIME header lines up to message body */ 659 660#define MIME_INVALID 0 661#define MIME_START 1 662#define MIME_TYPE 2 663#define MIME_NAME 3 664#define MIME_VALUE 4 665#define MIME_QUOTE 5 666#define MIME_COMMENT 6 667 668static STACK_OF(MIME_HEADER) * 669mime_parse_hdr(BIO *bio) 670{ 671 char *p, *q, c; 672 char *ntmp; 673 char linebuf[MAX_SMLEN]; 674 MIME_HEADER *mhdr = NULL; 675 STACK_OF(MIME_HEADER) *headers; 676 int len, state, save_state = 0; 677 678 headers = sk_MIME_HEADER_new(mime_hdr_cmp); 679 if (!headers) 680 return NULL; 681 while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) { 682 /* If whitespace at line start then continuation line */ 683 if (mhdr && isspace((unsigned char)linebuf[0])) 684 state = MIME_NAME; 685 else 686 state = MIME_START; 687 ntmp = NULL; 688 689 /* Go through all characters */ 690 for (p = linebuf, q = linebuf; 691 (c = *p) && (c != '\r') && (c != '\n'); p++) { 692 693 /* State machine to handle MIME headers 694 * if this looks horrible that's because it *is* 695 */ 696 697 switch (state) { 698 case MIME_START: 699 if (c == ':') { 700 state = MIME_TYPE; 701 *p = 0; 702 ntmp = strip_ends(q); 703 q = p + 1; 704 } 705 break; 706 707 case MIME_TYPE: 708 if (c == ';') { 709 *p = 0; 710 mhdr = mime_hdr_new(ntmp, 711 strip_ends(q)); 712 if (mhdr == NULL) 713 goto merr; 714 if (sk_MIME_HEADER_push(headers, 715 mhdr) == 0) 716 goto merr; 717 ntmp = NULL; 718 q = p + 1; 719 state = MIME_NAME; 720 } else if (c == '(') { 721 save_state = state; 722 state = MIME_COMMENT; 723 } 724 break; 725 726 case MIME_COMMENT: 727 if (c == ')') { 728 state = save_state; 729 } 730 break; 731 732 case MIME_NAME: 733 if (c == '=') { 734 state = MIME_VALUE; 735 *p = 0; 736 ntmp = strip_ends(q); 737 q = p + 1; 738 } 739 break; 740 741 case MIME_VALUE: 742 if (c == ';') { 743 state = MIME_NAME; 744 *p = 0; 745 mime_hdr_addparam(mhdr, ntmp, 746 strip_ends(q)); 747 ntmp = NULL; 748 q = p + 1; 749 } else if (c == '"') { 750 state = MIME_QUOTE; 751 } else if (c == '(') { 752 save_state = state; 753 state = MIME_COMMENT; 754 } 755 break; 756 757 case MIME_QUOTE: 758 if (c == '"') { 759 state = MIME_VALUE; 760 } 761 break; 762 } 763 } 764 765 if (state == MIME_TYPE) { 766 mhdr = mime_hdr_new(ntmp, strip_ends(q)); 767 if (mhdr == NULL) 768 goto merr; 769 if (sk_MIME_HEADER_push(headers, mhdr) == 0) 770 goto merr; 771 } else if (state == MIME_VALUE) 772 mime_hdr_addparam(mhdr, ntmp, strip_ends(q)); 773 774 if (p == linebuf) 775 break; /* Blank line means end of headers */ 776 } 777 778 return headers; 779 780 merr: 781 if (mhdr != NULL) 782 mime_hdr_free(mhdr); 783 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 784 return NULL; 785} 786 787static char * 788strip_ends(char *name) 789{ 790 return strip_end(strip_start(name)); 791} 792 793/* Strip a parameter of whitespace from start of param */ 794static char * 795strip_start(char *name) 796{ 797 char *p, c; 798 799 /* Look for first non white space or quote */ 800 for (p = name; (c = *p); p++) { 801 if (c == '"') { 802 /* Next char is start of string if non null */ 803 if (p[1]) 804 return p + 1; 805 /* Else null string */ 806 return NULL; 807 } 808 if (!isspace((unsigned char)c)) 809 return p; 810 } 811 return NULL; 812} 813 814/* As above but strip from end of string : maybe should handle brackets? */ 815static char * 816strip_end(char *name) 817{ 818 char *p, c; 819 820 if (!name) 821 return NULL; 822 823 /* Look for first non white space or quote */ 824 for (p = name + strlen(name) - 1; p >= name; p--) { 825 c = *p; 826 if (c == '"') { 827 if (p - 1 == name) 828 return NULL; 829 *p = 0; 830 return name; 831 } 832 if (isspace((unsigned char)c)) 833 *p = 0; 834 else 835 return name; 836 } 837 return NULL; 838} 839 840static MIME_HEADER * 841mime_hdr_new(char *name, char *value) 842{ 843 MIME_HEADER *mhdr; 844 char *tmpname = NULL, *tmpval = NULL, *p; 845 846 if (name) { 847 if (!(tmpname = strdup(name))) 848 goto err; 849 for (p = tmpname; *p; p++) 850 *p = tolower((unsigned char)*p); 851 } 852 if (value) { 853 if (!(tmpval = strdup(value))) 854 goto err; 855 for (p = tmpval; *p; p++) 856 *p = tolower((unsigned char)*p); 857 } 858 mhdr = malloc(sizeof(MIME_HEADER)); 859 if (!mhdr) 860 goto err; 861 mhdr->name = tmpname; 862 mhdr->value = tmpval; 863 if (!(mhdr->params = sk_MIME_PARAM_new(mime_param_cmp))) { 864 free(mhdr); 865 goto err; 866 } 867 return mhdr; 868 err: 869 free(tmpname); 870 free(tmpval); 871 return NULL; 872} 873 874static int 875mime_hdr_addparam(MIME_HEADER *mhdr, char *name, char *value) 876{ 877 char *tmpname = NULL, *tmpval = NULL, *p; 878 MIME_PARAM *mparam; 879 880 if (name) { 881 tmpname = strdup(name); 882 if (!tmpname) 883 goto err; 884 for (p = tmpname; *p; p++) 885 *p = tolower((unsigned char)*p); 886 } 887 if (value) { 888 tmpval = strdup(value); 889 if (!tmpval) 890 goto err; 891 } 892 /* Parameter values are case sensitive so leave as is */ 893 mparam = malloc(sizeof(MIME_PARAM)); 894 if (!mparam) 895 goto err; 896 mparam->param_name = tmpname; 897 mparam->param_value = tmpval; 898 if (sk_MIME_PARAM_push(mhdr->params, mparam) == 0) { 899 free(mparam); 900 goto err; 901 } 902 return 1; 903 err: 904 free(tmpname); 905 free(tmpval); 906 return 0; 907} 908 909static int 910mime_hdr_cmp(const MIME_HEADER * const *a, const MIME_HEADER * const *b) 911{ 912 if (!(*a)->name || !(*b)->name) 913 return !!(*a)->name - !!(*b)->name; 914 return (strcmp((*a)->name, (*b)->name)); 915} 916 917static int 918mime_param_cmp(const MIME_PARAM * const *a, const MIME_PARAM * const *b) 919{ 920 if (!(*a)->param_name || !(*b)->param_name) 921 return !!(*a)->param_name - !!(*b)->param_name; 922 return (strcmp((*a)->param_name, (*b)->param_name)); 923} 924 925/* Find a header with a given name (if possible) */ 926 927static MIME_HEADER * 928mime_hdr_find(STACK_OF(MIME_HEADER) *hdrs, char *name) 929{ 930 MIME_HEADER htmp; 931 int idx; 932 htmp.name = name; 933 idx = sk_MIME_HEADER_find(hdrs, &htmp); 934 if (idx < 0) 935 return NULL; 936 return sk_MIME_HEADER_value(hdrs, idx); 937} 938 939static MIME_PARAM * 940mime_param_find(MIME_HEADER *hdr, char *name) 941{ 942 MIME_PARAM param; 943 int idx; 944 param.param_name = name; 945 idx = sk_MIME_PARAM_find(hdr->params, ¶m); 946 if (idx < 0) 947 return NULL; 948 return sk_MIME_PARAM_value(hdr->params, idx); 949} 950 951static void 952mime_hdr_free(MIME_HEADER *hdr) 953{ 954 free(hdr->name); 955 free(hdr->value); 956 if (hdr->params) 957 sk_MIME_PARAM_pop_free(hdr->params, mime_param_free); 958 free(hdr); 959} 960 961static void 962mime_param_free(MIME_PARAM *param) 963{ 964 free(param->param_name); 965 free(param->param_value); 966 free(param); 967} 968 969/* Check for a multipart boundary. Returns: 970 * 0 : no boundary 971 * 1 : part boundary 972 * 2 : final boundary 973 */ 974static int 975mime_bound_check(char *line, int linelen, char *bound, int blen) 976{ 977 if (linelen == -1) 978 linelen = strlen(line); 979 if (blen == -1) 980 blen = strlen(bound); 981 /* Quickly eliminate if line length too short */ 982 if (blen + 2 > linelen) 983 return 0; 984 /* Check for part boundary */ 985 if (!strncmp(line, "--", 2) && !strncmp(line + 2, bound, blen)) { 986 if (!strncmp(line + blen + 2, "--", 2)) 987 return 2; 988 else 989 return 1; 990 } 991 return 0; 992} 993 994static int 995strip_eol(char *linebuf, int *plen) 996{ 997 int len = *plen; 998 char *p, c; 999 int is_eol = 0; 1000 1001 for (p = linebuf + len - 1; len > 0; len--, p--) { 1002 c = *p; 1003 if (c == '\n') 1004 is_eol = 1; 1005 else if (c != '\r') 1006 break; 1007 } 1008 *plen = len; 1009 return is_eol; 1010} 1011