1 /* $OpenBSD: asn_mime.c,v 1.29 2021/12/25 13:17:48 jsing 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_locl.h" 66 #include "evp_locl.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 #define mime_debug(x) /* x */ 114 115 /* Output an ASN1 structure in BER format streaming if necessary */ 116 117 int 118 i2d_ASN1_bio_stream(BIO *out, ASN1_VALUE *val, BIO *in, int flags, 119 const ASN1_ITEM *it) 120 { 121 /* If streaming create stream BIO and copy all content through it */ 122 if (flags & SMIME_STREAM) { 123 BIO *bio, *tbio; 124 bio = BIO_new_NDEF(out, val, it); 125 if (!bio) { 126 ASN1error(ERR_R_MALLOC_FAILURE); 127 return 0; 128 } 129 SMIME_crlf_copy(in, bio, flags); 130 (void)BIO_flush(bio); 131 /* Free up successive BIOs until we hit the old output BIO */ 132 do { 133 tbio = BIO_pop(bio); 134 BIO_free(bio); 135 bio = tbio; 136 } while (bio != out); 137 } 138 /* else just write out ASN1 structure which will have all content 139 * stored internally 140 */ 141 else 142 ASN1_item_i2d_bio(it, out, val); 143 return 1; 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 /* 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 */ 426 427 ASN1_VALUE * 428 SMIME_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 */ 533 int 534 SMIME_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 } 568 569 /* Strip off headers if they are text/plain */ 570 int 571 SMIME_text(BIO *in, BIO *out) 572 { 573 char iobuf[4096]; 574 int len; 575 STACK_OF(MIME_HEADER) *headers; 576 MIME_HEADER *hdr; 577 578 if (!(headers = mime_parse_hdr(in))) { 579 ASN1error(ASN1_R_MIME_PARSE_ERROR); 580 return 0; 581 } 582 if (!(hdr = mime_hdr_find(headers, "content-type")) || !hdr->value) { 583 ASN1error(ASN1_R_MIME_NO_CONTENT_TYPE); 584 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 585 return 0; 586 } 587 if (strcmp (hdr->value, "text/plain")) { 588 ASN1error(ASN1_R_INVALID_MIME_TYPE); 589 ERR_asprintf_error_data("type: %s", hdr->value); 590 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 591 return 0; 592 } 593 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 594 while ((len = BIO_read(in, iobuf, sizeof(iobuf))) > 0) 595 BIO_write(out, iobuf, len); 596 if (len < 0) 597 return 0; 598 return 1; 599 } 600 601 /* 602 * Split a multipart/XXX message body into component parts: result is 603 * canonical parts in a STACK of bios 604 */ 605 static int 606 multi_split(BIO *bio, char *bound, STACK_OF(BIO) **ret) 607 { 608 char linebuf[MAX_SMLEN]; 609 int len, blen; 610 int eol = 0, next_eol = 0; 611 BIO *bpart = NULL; 612 STACK_OF(BIO) *parts; 613 char state, part, first; 614 615 blen = strlen(bound); 616 part = 0; 617 state = 0; 618 first = 1; 619 parts = sk_BIO_new_null(); 620 *ret = parts; 621 if (parts == NULL) 622 return 0; 623 while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) { 624 state = mime_bound_check(linebuf, len, bound, blen); 625 if (state == 1) { 626 first = 1; 627 part++; 628 } else if (state == 2) { 629 if (sk_BIO_push(parts, bpart) == 0) 630 return 0; 631 return 1; 632 } else if (part) { 633 /* Strip CR+LF from linebuf */ 634 next_eol = strip_eol(linebuf, &len); 635 if (first) { 636 first = 0; 637 if (bpart != NULL) { 638 if (sk_BIO_push(parts, bpart) == 0) 639 return 0; 640 } 641 bpart = BIO_new(BIO_s_mem()); 642 if (bpart == NULL) 643 return 0; 644 BIO_set_mem_eof_return(bpart, 0); 645 } else if (eol) 646 BIO_write(bpart, "\r\n", 2); 647 eol = next_eol; 648 if (len) 649 BIO_write(bpart, linebuf, len); 650 } 651 } 652 BIO_free(bpart); 653 return 0; 654 } 655 656 /* This is the big one: parse MIME header lines up to message body */ 657 658 #define MIME_INVALID 0 659 #define MIME_START 1 660 #define MIME_TYPE 2 661 #define MIME_NAME 3 662 #define MIME_VALUE 4 663 #define MIME_QUOTE 5 664 #define MIME_COMMENT 6 665 666 667 static 668 STACK_OF(MIME_HEADER) *mime_parse_hdr(BIO *bio) 669 { 670 char *p, *q, c; 671 char *ntmp; 672 char linebuf[MAX_SMLEN]; 673 MIME_HEADER *mhdr = NULL; 674 STACK_OF(MIME_HEADER) *headers; 675 int len, state, save_state = 0; 676 677 headers = sk_MIME_HEADER_new(mime_hdr_cmp); 678 if (!headers) 679 return NULL; 680 while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) { 681 /* If whitespace at line start then continuation line */ 682 if (mhdr && isspace((unsigned char)linebuf[0])) 683 state = MIME_NAME; 684 else 685 state = MIME_START; 686 ntmp = NULL; 687 688 /* Go through all characters */ 689 for (p = linebuf, q = linebuf; 690 (c = *p) && (c != '\r') && (c != '\n'); p++) { 691 692 /* State machine to handle MIME headers 693 * if this looks horrible that's because it *is* 694 */ 695 696 switch (state) { 697 case MIME_START: 698 if (c == ':') { 699 state = MIME_TYPE; 700 *p = 0; 701 ntmp = strip_ends(q); 702 q = p + 1; 703 } 704 break; 705 706 case MIME_TYPE: 707 if (c == ';') { 708 mime_debug("Found End Value\n"); 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 mime_debug("Found Quote\n"); 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 mime_debug("Found Match Quote\n"); 761 state = MIME_VALUE; 762 } 763 break; 764 } 765 } 766 767 if (state == MIME_TYPE) { 768 mhdr = mime_hdr_new(ntmp, strip_ends(q)); 769 if (mhdr == NULL) 770 goto merr; 771 if (sk_MIME_HEADER_push(headers, mhdr) == 0) 772 goto merr; 773 } else if (state == MIME_VALUE) 774 mime_hdr_addparam(mhdr, ntmp, strip_ends(q)); 775 776 if (p == linebuf) 777 break; /* Blank line means end of headers */ 778 } 779 780 return headers; 781 782 merr: 783 if (mhdr != NULL) 784 mime_hdr_free(mhdr); 785 sk_MIME_HEADER_pop_free(headers, mime_hdr_free); 786 return NULL; 787 } 788 789 static char * 790 strip_ends(char *name) 791 { 792 return strip_end(strip_start(name)); 793 } 794 795 /* Strip a parameter of whitespace from start of param */ 796 static char * 797 strip_start(char *name) 798 { 799 char *p, c; 800 801 /* Look for first non white space or quote */ 802 for (p = name; (c = *p); p++) { 803 if (c == '"') { 804 /* Next char is start of string if non null */ 805 if (p[1]) 806 return p + 1; 807 /* Else null string */ 808 return NULL; 809 } 810 if (!isspace((unsigned char)c)) 811 return p; 812 } 813 return NULL; 814 } 815 816 /* As above but strip from end of string : maybe should handle brackets? */ 817 static char * 818 strip_end(char *name) 819 { 820 char *p, c; 821 822 if (!name) 823 return NULL; 824 825 /* Look for first non white space or quote */ 826 for (p = name + strlen(name) - 1; p >= name; p--) { 827 c = *p; 828 if (c == '"') { 829 if (p - 1 == name) 830 return NULL; 831 *p = 0; 832 return name; 833 } 834 if (isspace((unsigned char)c)) 835 *p = 0; 836 else 837 return name; 838 } 839 return NULL; 840 } 841 842 static MIME_HEADER * 843 mime_hdr_new(char *name, char *value) 844 { 845 MIME_HEADER *mhdr; 846 char *tmpname = NULL, *tmpval = NULL, *p; 847 848 if (name) { 849 if (!(tmpname = strdup(name))) 850 goto err; 851 for (p = tmpname; *p; p++) 852 *p = tolower((unsigned char)*p); 853 } 854 if (value) { 855 if (!(tmpval = strdup(value))) 856 goto err; 857 for (p = tmpval; *p; p++) 858 *p = tolower((unsigned char)*p); 859 } 860 mhdr = malloc(sizeof(MIME_HEADER)); 861 if (!mhdr) 862 goto err; 863 mhdr->name = tmpname; 864 mhdr->value = tmpval; 865 if (!(mhdr->params = sk_MIME_PARAM_new(mime_param_cmp))) { 866 free(mhdr); 867 goto err; 868 } 869 return mhdr; 870 err: 871 free(tmpname); 872 free(tmpval); 873 return NULL; 874 } 875 876 static int 877 mime_hdr_addparam(MIME_HEADER *mhdr, char *name, char *value) 878 { 879 char *tmpname = NULL, *tmpval = NULL, *p; 880 MIME_PARAM *mparam; 881 882 if (name) { 883 tmpname = strdup(name); 884 if (!tmpname) 885 goto err; 886 for (p = tmpname; *p; p++) 887 *p = tolower((unsigned char)*p); 888 } 889 if (value) { 890 tmpval = strdup(value); 891 if (!tmpval) 892 goto err; 893 } 894 /* Parameter values are case sensitive so leave as is */ 895 mparam = malloc(sizeof(MIME_PARAM)); 896 if (!mparam) 897 goto err; 898 mparam->param_name = tmpname; 899 mparam->param_value = tmpval; 900 if (sk_MIME_PARAM_push(mhdr->params, mparam) == 0) { 901 free(mparam); 902 goto err; 903 } 904 return 1; 905 err: 906 free(tmpname); 907 free(tmpval); 908 return 0; 909 } 910 911 static int 912 mime_hdr_cmp(const MIME_HEADER * const *a, const MIME_HEADER * const *b) 913 { 914 if (!(*a)->name || !(*b)->name) 915 return !!(*a)->name - !!(*b)->name; 916 return (strcmp((*a)->name, (*b)->name)); 917 } 918 919 static int 920 mime_param_cmp(const MIME_PARAM * const *a, const MIME_PARAM * const *b) 921 { 922 if (!(*a)->param_name || !(*b)->param_name) 923 return !!(*a)->param_name - !!(*b)->param_name; 924 return (strcmp((*a)->param_name, (*b)->param_name)); 925 } 926 927 /* Find a header with a given name (if possible) */ 928 929 static MIME_HEADER * 930 mime_hdr_find(STACK_OF(MIME_HEADER) *hdrs, char *name) 931 { 932 MIME_HEADER htmp; 933 int idx; 934 htmp.name = name; 935 idx = sk_MIME_HEADER_find(hdrs, &htmp); 936 if (idx < 0) 937 return NULL; 938 return sk_MIME_HEADER_value(hdrs, idx); 939 } 940 941 static MIME_PARAM * 942 mime_param_find(MIME_HEADER *hdr, char *name) 943 { 944 MIME_PARAM param; 945 int idx; 946 param.param_name = name; 947 idx = sk_MIME_PARAM_find(hdr->params, ¶m); 948 if (idx < 0) 949 return NULL; 950 return sk_MIME_PARAM_value(hdr->params, idx); 951 } 952 953 static void 954 mime_hdr_free(MIME_HEADER *hdr) 955 { 956 free(hdr->name); 957 free(hdr->value); 958 if (hdr->params) 959 sk_MIME_PARAM_pop_free(hdr->params, mime_param_free); 960 free(hdr); 961 } 962 963 static void 964 mime_param_free(MIME_PARAM *param) 965 { 966 free(param->param_name); 967 free(param->param_value); 968 free(param); 969 } 970 971 /* Check for a multipart boundary. Returns: 972 * 0 : no boundary 973 * 1 : part boundary 974 * 2 : final boundary 975 */ 976 static int 977 mime_bound_check(char *line, int linelen, char *bound, int blen) 978 { 979 if (linelen == -1) 980 linelen = strlen(line); 981 if (blen == -1) 982 blen = strlen(bound); 983 /* Quickly eliminate if line length too short */ 984 if (blen + 2 > linelen) 985 return 0; 986 /* Check for part boundary */ 987 if (!strncmp(line, "--", 2) && !strncmp(line + 2, bound, blen)) { 988 if (!strncmp(line + blen + 2, "--", 2)) 989 return 2; 990 else 991 return 1; 992 } 993 return 0; 994 } 995 996 static int 997 strip_eol(char *linebuf, int *plen) 998 { 999 int len = *plen; 1000 char *p, c; 1001 int is_eol = 0; 1002 1003 for (p = linebuf + len - 1; len > 0; len--, p--) { 1004 c = *p; 1005 if (c == '\n') 1006 is_eol = 1; 1007 else if (c != '\r') 1008 break; 1009 } 1010 *plen = len; 1011 return is_eol; 1012 } 1013