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