1 /* $OpenBSD: asn_mime.c,v 1.35 2025/01/17 05:02:18 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 77 typedef struct { 78 char *param_name; /* Param name e.g. "micalg" */ 79 char *param_value; /* Param value e.g. "sha1" */ 80 } MIME_PARAM; 81 82 DECLARE_STACK_OF(MIME_PARAM) 83 84 typedef 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 90 DECLARE_STACK_OF(MIME_HEADER) 91 92 static int asn1_output_data(BIO *out, BIO *data, ASN1_VALUE *val, int flags, 93 const ASN1_ITEM *it); 94 static char * strip_ends(char *name); 95 static char * strip_start(char *name); 96 static char * strip_end(char *name); 97 static MIME_HEADER *mime_hdr_new(char *name, char *value); 98 static int mime_hdr_addparam(MIME_HEADER *mhdr, char *name, char *value); 99 static STACK_OF(MIME_HEADER) *mime_parse_hdr(BIO *bio); 100 static int mime_hdr_cmp(const MIME_HEADER * const *a, 101 const MIME_HEADER * const *b); 102 static int mime_param_cmp(const MIME_PARAM * const *a, 103 const MIME_PARAM * const *b); 104 static void mime_param_free(MIME_PARAM *param); 105 static int mime_bound_check(char *line, int linelen, char *bound, int blen); 106 static int multi_split(BIO *bio, char *bound, STACK_OF(BIO) **ret); 107 static int strip_eol(char *linebuf, int *plen); 108 static MIME_HEADER *mime_hdr_find(STACK_OF(MIME_HEADER) *hdrs, char *name); 109 static MIME_PARAM *mime_param_find(MIME_HEADER *hdr, char *name); 110 static 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 */ 115 116 int 117 i2d_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 */ 147 148 static int 149 B64_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 */ 171 172 int 173 PEM_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 } 183 184 static ASN1_VALUE * 185 b64_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 */ 204 205 static int 206 asn1_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 */ 276 277 int 278 SMIME_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 */ 371 372 373 static int 374 asn1_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 /* 383 * If data is not detached or resigning then the output BIO is 384 * already set up to finalise when it is written through. 385 */ 386 if (!(flags & SMIME_DETACHED) || (flags & PKCS7_REUSE_DIGEST)) { 387 SMIME_crlf_copy(data, out, flags); 388 return 1; 389 } 390 391 if (!aux || !aux->asn1_cb) { 392 ASN1error(ASN1_R_STREAMING_NOT_SUPPORTED); 393 return 0; 394 } 395 396 sarg.out = out; 397 sarg.ndef_bio = NULL; 398 sarg.boundary = NULL; 399 400 /* Let ASN1 code prepend any needed BIOs */ 401 402 if (aux->asn1_cb(ASN1_OP_DETACHED_PRE, &val, it, &sarg) <= 0) 403 return 0; 404 405 /* Copy data across, passing through filter BIOs for processing */ 406 SMIME_crlf_copy(data, sarg.ndef_bio, flags); 407 408 /* Finalize structure */ 409 if (aux->asn1_cb(ASN1_OP_DETACHED_POST, &val, it, &sarg) <= 0) 410 rv = 0; 411 412 /* Now remove any digests prepended to the BIO */ 413 414 while (sarg.ndef_bio != out) { 415 tmpbio = BIO_pop(sarg.ndef_bio); 416 BIO_free(sarg.ndef_bio); 417 sarg.ndef_bio = tmpbio; 418 } 419 420 return rv; 421 } 422 423 /* SMIME reader: handle multipart/signed and opaque signing. 424 * in multipart case the content is placed in a memory BIO 425 * pointed to by "bcont". In opaque this is set to NULL 426 */ 427 428 ASN1_VALUE * 429 SMIME_read_ASN1(BIO *bio, BIO **bcont, const ASN1_ITEM *it) 430 { 431 BIO *asnin; 432 STACK_OF(MIME_HEADER) *headers = NULL; 433 STACK_OF(BIO) *parts = NULL; 434 MIME_HEADER *hdr; 435 MIME_PARAM *prm; 436 ASN1_VALUE *val; 437 int ret; 438 439 if (bcont) 440 *bcont = NULL; 441 442 if (!(headers = mime_parse_hdr(bio))) { 443 ASN1error(ASN1_R_MIME_PARSE_ERROR); 444 return NULL; 445 } 446 447 if (!(hdr = mime_hdr_find(headers, "content-type")) || !hdr->value) { 448 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 449 ASN1error(ASN1_R_NO_CONTENT_TYPE); 450 return NULL; 451 } 452 453 /* Handle multipart/signed */ 454 455 if (!strcmp(hdr->value, "multipart/signed")) { 456 /* Split into two parts */ 457 prm = mime_param_find(hdr, "boundary"); 458 if (!prm || !prm->param_value) { 459 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 460 ASN1error(ASN1_R_NO_MULTIPART_BOUNDARY); 461 return NULL; 462 } 463 ret = multi_split(bio, prm->param_value, &parts); 464 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 465 if (!ret || (sk_BIO_num(parts) != 2) ) { 466 ASN1error(ASN1_R_NO_MULTIPART_BODY_FAILURE); 467 sk_BIO_pop_free(parts, BIO_vfree); 468 return NULL; 469 } 470 471 /* Parse the signature piece */ 472 asnin = sk_BIO_value(parts, 1); 473 474 if (!(headers = mime_parse_hdr(asnin))) { 475 ASN1error(ASN1_R_MIME_SIG_PARSE_ERROR); 476 sk_BIO_pop_free(parts, BIO_vfree); 477 return NULL; 478 } 479 480 /* Get content type */ 481 482 if (!(hdr = mime_hdr_find(headers, "content-type")) || 483 !hdr->value) { 484 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 485 sk_BIO_pop_free(parts, BIO_vfree); 486 ASN1error(ASN1_R_NO_SIG_CONTENT_TYPE); 487 return NULL; 488 } 489 490 if (strcmp(hdr->value, "application/x-pkcs7-signature") && 491 strcmp(hdr->value, "application/pkcs7-signature")) { 492 ASN1error(ASN1_R_SIG_INVALID_MIME_TYPE); 493 ERR_asprintf_error_data("type: %s", hdr->value); 494 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 495 sk_BIO_pop_free(parts, BIO_vfree); 496 return NULL; 497 } 498 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 499 /* Read in ASN1 */ 500 if (!(val = b64_read_asn1(asnin, it))) { 501 ASN1error(ASN1_R_ASN1_SIG_PARSE_ERROR); 502 sk_BIO_pop_free(parts, BIO_vfree); 503 return NULL; 504 } 505 506 if (bcont) { 507 *bcont = sk_BIO_value(parts, 0); 508 BIO_free(asnin); 509 sk_BIO_free(parts); 510 } else sk_BIO_pop_free(parts, BIO_vfree); 511 return val; 512 } 513 514 /* OK, if not multipart/signed try opaque signature */ 515 516 if (strcmp (hdr->value, "application/x-pkcs7-mime") && 517 strcmp (hdr->value, "application/pkcs7-mime")) { 518 ASN1error(ASN1_R_INVALID_MIME_TYPE); 519 ERR_asprintf_error_data("type: %s", hdr->value); 520 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 521 return NULL; 522 } 523 524 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 525 526 if (!(val = b64_read_asn1(bio, it))) { 527 ASN1error(ASN1_R_ASN1_PARSE_ERROR); 528 return NULL; 529 } 530 return val; 531 } 532 533 /* Copy text from one BIO to another making the output CRLF at EOL */ 534 int 535 SMIME_crlf_copy(BIO *in, BIO *out, int flags) 536 { 537 BIO *bf; 538 char eol; 539 int len; 540 char linebuf[MAX_SMLEN]; 541 542 /* Buffer output so we don't write one line at a time. This is 543 * useful when streaming as we don't end up with one OCTET STRING 544 * per line. 545 */ 546 bf = BIO_new(BIO_f_buffer()); 547 if (!bf) 548 return 0; 549 out = BIO_push(bf, out); 550 if (flags & SMIME_BINARY) { 551 while ((len = BIO_read(in, linebuf, MAX_SMLEN)) > 0) 552 BIO_write(out, linebuf, len); 553 } else { 554 if (flags & SMIME_TEXT) 555 BIO_printf(out, "Content-Type: text/plain\r\n\r\n"); 556 while ((len = BIO_gets(in, linebuf, MAX_SMLEN)) > 0) { 557 eol = strip_eol(linebuf, &len); 558 if (len) 559 BIO_write(out, linebuf, len); 560 if (eol) 561 BIO_write(out, "\r\n", 2); 562 } 563 } 564 (void)BIO_flush(out); 565 BIO_pop(out); 566 BIO_free(bf); 567 return 1; 568 } 569 LCRYPTO_ALIAS(SMIME_crlf_copy); 570 571 /* Strip off headers if they are text/plain */ 572 int 573 SMIME_text(BIO *in, BIO *out) 574 { 575 char iobuf[4096]; 576 int len; 577 STACK_OF(MIME_HEADER) *headers; 578 MIME_HEADER *hdr; 579 580 if (!(headers = mime_parse_hdr(in))) { 581 ASN1error(ASN1_R_MIME_PARSE_ERROR); 582 return 0; 583 } 584 if (!(hdr = mime_hdr_find(headers, "content-type")) || !hdr->value) { 585 ASN1error(ASN1_R_MIME_NO_CONTENT_TYPE); 586 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 587 return 0; 588 } 589 if (strcmp (hdr->value, "text/plain")) { 590 ASN1error(ASN1_R_INVALID_MIME_TYPE); 591 ERR_asprintf_error_data("type: %s", hdr->value); 592 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 593 return 0; 594 } 595 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 596 while ((len = BIO_read(in, iobuf, sizeof(iobuf))) > 0) 597 BIO_write(out, iobuf, len); 598 if (len < 0) 599 return 0; 600 return 1; 601 } 602 LCRYPTO_ALIAS(SMIME_text); 603 604 /* 605 * Split a multipart/XXX message body into component parts: result is 606 * canonical parts in a STACK of bios 607 */ 608 static int 609 multi_split(BIO *bio, char *bound, STACK_OF(BIO) **ret) 610 { 611 char linebuf[MAX_SMLEN]; 612 int len, blen; 613 int eol = 0, next_eol = 0; 614 BIO *bpart = NULL; 615 STACK_OF(BIO) *parts; 616 char state, part, first; 617 618 blen = strlen(bound); 619 part = 0; 620 state = 0; 621 first = 1; 622 parts = sk_BIO_new_null(); 623 *ret = parts; 624 if (parts == NULL) 625 return 0; 626 while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) { 627 state = mime_bound_check(linebuf, len, bound, blen); 628 if (state == 1) { 629 first = 1; 630 part++; 631 } else if (state == 2) { 632 if (sk_BIO_push(parts, bpart) == 0) 633 return 0; 634 return 1; 635 } else if (part) { 636 /* Strip CR+LF from linebuf */ 637 next_eol = strip_eol(linebuf, &len); 638 if (first) { 639 first = 0; 640 if (bpart != NULL) { 641 if (sk_BIO_push(parts, bpart) == 0) 642 return 0; 643 } 644 bpart = BIO_new(BIO_s_mem()); 645 if (bpart == NULL) 646 return 0; 647 BIO_set_mem_eof_return(bpart, 0); 648 } else if (eol) 649 BIO_write(bpart, "\r\n", 2); 650 eol = next_eol; 651 if (len) 652 BIO_write(bpart, linebuf, len); 653 } 654 } 655 BIO_free(bpart); 656 return 0; 657 } 658 659 /* This is the big one: parse MIME header lines up to message body */ 660 661 #define MIME_INVALID 0 662 #define MIME_START 1 663 #define MIME_TYPE 2 664 #define MIME_NAME 3 665 #define MIME_VALUE 4 666 #define MIME_QUOTE 5 667 #define MIME_COMMENT 6 668 669 static STACK_OF(MIME_HEADER) * 670 mime_parse_hdr(BIO *bio) 671 { 672 char *p, *q, c; 673 char *ntmp; 674 char linebuf[MAX_SMLEN]; 675 MIME_HEADER *mhdr = NULL; 676 STACK_OF(MIME_HEADER) *headers; 677 int len, state, save_state = 0; 678 679 headers = sk_MIME_HEADER_new(mime_hdr_cmp); 680 if (!headers) 681 return NULL; 682 while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) { 683 /* If whitespace at line start then continuation line */ 684 if (mhdr && isspace((unsigned char)linebuf[0])) 685 state = MIME_NAME; 686 else 687 state = MIME_START; 688 ntmp = NULL; 689 690 /* Go through all characters */ 691 for (p = linebuf, q = linebuf; 692 (c = *p) && (c != '\r') && (c != '\n'); p++) { 693 694 /* State machine to handle MIME headers 695 * if this looks horrible that's because it *is* 696 */ 697 698 switch (state) { 699 case MIME_START: 700 if (c == ':') { 701 state = MIME_TYPE; 702 *p = 0; 703 ntmp = strip_ends(q); 704 q = p + 1; 705 } 706 break; 707 708 case MIME_TYPE: 709 if (c == ';') { 710 *p = 0; 711 mhdr = mime_hdr_new(ntmp, 712 strip_ends(q)); 713 if (mhdr == NULL) 714 goto merr; 715 if (sk_MIME_HEADER_push(headers, 716 mhdr) == 0) 717 goto merr; 718 ntmp = NULL; 719 q = p + 1; 720 state = MIME_NAME; 721 } else if (c == '(') { 722 save_state = state; 723 state = MIME_COMMENT; 724 } 725 break; 726 727 case MIME_COMMENT: 728 if (c == ')') { 729 state = save_state; 730 } 731 break; 732 733 case MIME_NAME: 734 if (c == '=') { 735 state = MIME_VALUE; 736 *p = 0; 737 ntmp = strip_ends(q); 738 q = p + 1; 739 } 740 break; 741 742 case MIME_VALUE: 743 if (c == ';') { 744 state = MIME_NAME; 745 *p = 0; 746 mime_hdr_addparam(mhdr, ntmp, 747 strip_ends(q)); 748 ntmp = NULL; 749 q = p + 1; 750 } else if (c == '"') { 751 state = MIME_QUOTE; 752 } else if (c == '(') { 753 save_state = state; 754 state = MIME_COMMENT; 755 } 756 break; 757 758 case MIME_QUOTE: 759 if (c == '"') { 760 state = MIME_VALUE; 761 } 762 break; 763 } 764 } 765 766 if (state == MIME_TYPE) { 767 mhdr = mime_hdr_new(ntmp, strip_ends(q)); 768 if (mhdr == NULL) 769 goto merr; 770 if (sk_MIME_HEADER_push(headers, mhdr) == 0) 771 goto merr; 772 } else if (state == MIME_VALUE) 773 mime_hdr_addparam(mhdr, ntmp, strip_ends(q)); 774 775 if (p == linebuf) 776 break; /* Blank line means end of headers */ 777 } 778 779 return headers; 780 781 merr: 782 if (mhdr != NULL) 783 mime_hdr_free(mhdr); 784 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 785 return NULL; 786 } 787 788 static char * 789 strip_ends(char *name) 790 { 791 return strip_end(strip_start(name)); 792 } 793 794 /* Strip a parameter of whitespace from start of param */ 795 static char * 796 strip_start(char *name) 797 { 798 char *p, c; 799 800 /* Look for first non white space or quote */ 801 for (p = name; (c = *p); p++) { 802 if (c == '"') { 803 /* Next char is start of string if non null */ 804 if (p[1]) 805 return p + 1; 806 /* Else null string */ 807 return NULL; 808 } 809 if (!isspace((unsigned char)c)) 810 return p; 811 } 812 return NULL; 813 } 814 815 /* As above but strip from end of string : maybe should handle brackets? */ 816 static char * 817 strip_end(char *name) 818 { 819 char *p, c; 820 821 if (!name) 822 return NULL; 823 824 /* Look for first non white space or quote */ 825 for (p = name + strlen(name) - 1; p >= name; p--) { 826 c = *p; 827 if (c == '"') { 828 if (p - 1 == name) 829 return NULL; 830 *p = 0; 831 return name; 832 } 833 if (isspace((unsigned char)c)) 834 *p = 0; 835 else 836 return name; 837 } 838 return NULL; 839 } 840 841 static MIME_HEADER * 842 mime_hdr_new(char *name, char *value) 843 { 844 MIME_HEADER *mhdr; 845 char *tmpname = NULL, *tmpval = NULL, *p; 846 847 if (name) { 848 if (!(tmpname = strdup(name))) 849 goto err; 850 for (p = tmpname; *p; p++) 851 *p = tolower((unsigned char)*p); 852 } 853 if (value) { 854 if (!(tmpval = strdup(value))) 855 goto err; 856 for (p = tmpval; *p; p++) 857 *p = tolower((unsigned char)*p); 858 } 859 mhdr = malloc(sizeof(MIME_HEADER)); 860 if (!mhdr) 861 goto err; 862 mhdr->name = tmpname; 863 mhdr->value = tmpval; 864 if (!(mhdr->params = sk_MIME_PARAM_new(mime_param_cmp))) { 865 free(mhdr); 866 goto err; 867 } 868 return mhdr; 869 err: 870 free(tmpname); 871 free(tmpval); 872 return NULL; 873 } 874 875 static int 876 mime_hdr_addparam(MIME_HEADER *mhdr, char *name, char *value) 877 { 878 char *tmpname = NULL, *tmpval = NULL, *p; 879 MIME_PARAM *mparam; 880 881 if (name) { 882 tmpname = strdup(name); 883 if (!tmpname) 884 goto err; 885 for (p = tmpname; *p; p++) 886 *p = tolower((unsigned char)*p); 887 } 888 if (value) { 889 tmpval = strdup(value); 890 if (!tmpval) 891 goto err; 892 } 893 /* Parameter values are case sensitive so leave as is */ 894 mparam = malloc(sizeof(MIME_PARAM)); 895 if (!mparam) 896 goto err; 897 mparam->param_name = tmpname; 898 mparam->param_value = tmpval; 899 if (sk_MIME_PARAM_push(mhdr->params, mparam) == 0) { 900 free(mparam); 901 goto err; 902 } 903 return 1; 904 err: 905 free(tmpname); 906 free(tmpval); 907 return 0; 908 } 909 910 static int 911 mime_hdr_cmp(const MIME_HEADER * const *a, const MIME_HEADER * const *b) 912 { 913 if (!(*a)->name || !(*b)->name) 914 return !!(*a)->name - !!(*b)->name; 915 return (strcmp((*a)->name, (*b)->name)); 916 } 917 918 static int 919 mime_param_cmp(const MIME_PARAM * const *a, const MIME_PARAM * const *b) 920 { 921 if (!(*a)->param_name || !(*b)->param_name) 922 return !!(*a)->param_name - !!(*b)->param_name; 923 return (strcmp((*a)->param_name, (*b)->param_name)); 924 } 925 926 /* Find a header with a given name (if possible) */ 927 928 static MIME_HEADER * 929 mime_hdr_find(STACK_OF(MIME_HEADER) *hdrs, char *name) 930 { 931 MIME_HEADER htmp; 932 int idx; 933 htmp.name = name; 934 idx = sk_MIME_HEADER_find(hdrs, &htmp); 935 if (idx < 0) 936 return NULL; 937 return sk_MIME_HEADER_value(hdrs, idx); 938 } 939 940 static MIME_PARAM * 941 mime_param_find(MIME_HEADER *hdr, char *name) 942 { 943 MIME_PARAM param; 944 int idx; 945 param.param_name = name; 946 idx = sk_MIME_PARAM_find(hdr->params, ¶m); 947 if (idx < 0) 948 return NULL; 949 return sk_MIME_PARAM_value(hdr->params, idx); 950 } 951 952 static void 953 mime_hdr_free(MIME_HEADER *hdr) 954 { 955 free(hdr->name); 956 free(hdr->value); 957 if (hdr->params) 958 sk_MIME_PARAM_pop_free(hdr->params, mime_param_free); 959 free(hdr); 960 } 961 962 static void 963 mime_param_free(MIME_PARAM *param) 964 { 965 free(param->param_name); 966 free(param->param_value); 967 free(param); 968 } 969 970 /* Check for a multipart boundary. Returns: 971 * 0 : no boundary 972 * 1 : part boundary 973 * 2 : final boundary 974 */ 975 static int 976 mime_bound_check(char *line, int linelen, char *bound, int blen) 977 { 978 if (linelen == -1) 979 linelen = strlen(line); 980 if (blen == -1) 981 blen = strlen(bound); 982 /* Quickly eliminate if line length too short */ 983 if (blen + 2 > linelen) 984 return 0; 985 /* Check for part boundary */ 986 if (!strncmp(line, "--", 2) && !strncmp(line + 2, bound, blen)) { 987 if (!strncmp(line + blen + 2, "--", 2)) 988 return 2; 989 else 990 return 1; 991 } 992 return 0; 993 } 994 995 static int 996 strip_eol(char *linebuf, int *plen) 997 { 998 int len = *plen; 999 char *p, c; 1000 int is_eol = 0; 1001 1002 for (p = linebuf + len - 1; len > 0; len--, p--) { 1003 c = *p; 1004 if (c == '\n') 1005 is_eol = 1; 1006 else if (c != '\r') 1007 break; 1008 } 1009 *plen = len; 1010 return is_eol; 1011 } 1012