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
i2d_ASN1_bio_stream(BIO * out,ASN1_VALUE * val,BIO * in,int flags,const ASN1_ITEM * it)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
B64_write_ASN1(BIO * out,ASN1_VALUE * val,BIO * in,int flags,const ASN1_ITEM * it)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
PEM_write_bio_ASN1_stream(BIO * out,ASN1_VALUE * val,BIO * in,int flags,const char * hdr,const ASN1_ITEM * it)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 *
b64_read_asn1(BIO * bio,const ASN1_ITEM * it)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
asn1_write_micalg(BIO * out,STACK_OF (X509_ALGOR)* mdalgs)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
SMIME_write_ASN1(BIO * bio,ASN1_VALUE * val,BIO * data,int flags,int ctype_nid,int econt_nid,STACK_OF (X509_ALGOR)* mdalgs,const ASN1_ITEM * it)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
asn1_output_data(BIO * out,BIO * data,ASN1_VALUE * val,int flags,const ASN1_ITEM * it)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 *
SMIME_read_ASN1(BIO * bio,BIO ** bcont,const ASN1_ITEM * it)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
SMIME_crlf_copy(BIO * in,BIO * out,int flags)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
SMIME_text(BIO * in,BIO * out)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
multi_split(BIO * bio,char * bound,STACK_OF (BIO)** ret)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
STACK_OF(MIME_HEADER)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 *
strip_ends(char * name)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 *
strip_start(char * name)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 *
strip_end(char * name)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 *
mime_hdr_new(char * name,char * value)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
mime_hdr_addparam(MIME_HEADER * mhdr,char * name,char * value)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
mime_hdr_cmp(const MIME_HEADER * const * a,const MIME_HEADER * const * b)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
mime_param_cmp(const MIME_PARAM * const * a,const MIME_PARAM * const * b)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 *
mime_hdr_find(STACK_OF (MIME_HEADER)* hdrs,char * name)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 *
mime_param_find(MIME_HEADER * hdr,char * name)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
mime_hdr_free(MIME_HEADER * hdr)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
mime_param_free(MIME_PARAM * param)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
mime_bound_check(char * line,int linelen,char * bound,int blen)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
strip_eol(char * linebuf,int * plen)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