1 /*
2 * Copyright 2008-2020 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <stdio.h>
11 #include "crypto/ctype.h"
12 #include "internal/cryptlib.h"
13 #include <openssl/rand.h>
14 #include <openssl/x509.h>
15 #include <openssl/asn1.h>
16 #include <openssl/asn1t.h>
17 #include "crypto/evp.h"
18 #include "internal/bio.h"
19 #include "asn1_local.h"
20
21 /*
22 * Generalised MIME like utilities for streaming ASN1. Although many have a
23 * PKCS7/CMS like flavour others are more general purpose.
24 */
25
26 /*
27 * MIME format structures Note that all are translated to lower case apart
28 * from parameter values. Quotes are stripped off
29 */
30
31 struct mime_param_st {
32 char *param_name; /* Param name e.g. "micalg" */
33 char *param_value; /* Param value e.g. "sha1" */
34 };
35
36 struct mime_header_st {
37 char *name; /* Name of line e.g. "content-type" */
38 char *value; /* Value of line e.g. "text/plain" */
39 STACK_OF(MIME_PARAM) *params; /* Zero or more parameters */
40 };
41
42 static int asn1_output_data(BIO *out, BIO *data, ASN1_VALUE *val, int flags,
43 const ASN1_ITEM *it);
44 static char *strip_ends(char *name);
45 static char *strip_start(char *name);
46 static char *strip_end(char *name);
47 static MIME_HEADER *mime_hdr_new(const char *name, const char *value);
48 static int mime_hdr_addparam(MIME_HEADER *mhdr, const char *name, const char *value);
49 static STACK_OF(MIME_HEADER) *mime_parse_hdr(BIO *bio);
50 static int mime_hdr_cmp(const MIME_HEADER *const *a,
51 const MIME_HEADER *const *b);
52 static int mime_param_cmp(const MIME_PARAM *const *a,
53 const MIME_PARAM *const *b);
54 static void mime_param_free(MIME_PARAM *param);
55 static int mime_bound_check(char *line, int linelen, const char *bound, int blen);
56 static int multi_split(BIO *bio, const char *bound, STACK_OF(BIO) **ret);
57 static int strip_eol(char *linebuf, int *plen, int flags);
58 static MIME_HEADER *mime_hdr_find(STACK_OF(MIME_HEADER) *hdrs, const char *name);
59 static MIME_PARAM *mime_param_find(MIME_HEADER *hdr, const char *name);
60 static void mime_hdr_free(MIME_HEADER *hdr);
61
62 #define MAX_SMLEN 1024
63 #define mime_debug(x) /* x */
64
65 /* Output an ASN1 structure in BER format streaming if necessary */
66
i2d_ASN1_bio_stream(BIO * out,ASN1_VALUE * val,BIO * in,int flags,const ASN1_ITEM * it)67 int i2d_ASN1_bio_stream(BIO *out, ASN1_VALUE *val, BIO *in, int flags,
68 const ASN1_ITEM *it)
69 {
70 /* If streaming create stream BIO and copy all content through it */
71 if (flags & SMIME_STREAM) {
72 BIO *bio, *tbio;
73 bio = BIO_new_NDEF(out, val, it);
74 if (!bio) {
75 ASN1err(ASN1_F_I2D_ASN1_BIO_STREAM, ERR_R_MALLOC_FAILURE);
76 return 0;
77 }
78 SMIME_crlf_copy(in, bio, flags);
79 (void)BIO_flush(bio);
80 /* Free up successive BIOs until we hit the old output BIO */
81 do {
82 tbio = BIO_pop(bio);
83 BIO_free(bio);
84 bio = tbio;
85 } while (bio != out);
86 }
87 /*
88 * else just write out ASN1 structure which will have all content stored
89 * internally
90 */
91 else
92 ASN1_item_i2d_bio(it, out, val);
93 return 1;
94 }
95
96 /* Base 64 read and write of ASN1 structure */
97
B64_write_ASN1(BIO * out,ASN1_VALUE * val,BIO * in,int flags,const ASN1_ITEM * it)98 static int B64_write_ASN1(BIO *out, ASN1_VALUE *val, BIO *in, int flags,
99 const ASN1_ITEM *it)
100 {
101 BIO *b64;
102 int r;
103 b64 = BIO_new(BIO_f_base64());
104 if (b64 == NULL) {
105 ASN1err(ASN1_F_B64_WRITE_ASN1, ERR_R_MALLOC_FAILURE);
106 return 0;
107 }
108 /*
109 * prepend the b64 BIO so all data is base64 encoded.
110 */
111 out = BIO_push(b64, out);
112 r = i2d_ASN1_bio_stream(out, val, in, flags, it);
113 (void)BIO_flush(out);
114 BIO_pop(out);
115 BIO_free(b64);
116 return r;
117 }
118
119 /* Streaming ASN1 PEM write */
120
PEM_write_bio_ASN1_stream(BIO * out,ASN1_VALUE * val,BIO * in,int flags,const char * hdr,const ASN1_ITEM * it)121 int PEM_write_bio_ASN1_stream(BIO *out, ASN1_VALUE *val, BIO *in, int flags,
122 const char *hdr, const ASN1_ITEM *it)
123 {
124 int r;
125 BIO_printf(out, "-----BEGIN %s-----\n", hdr);
126 r = B64_write_ASN1(out, val, in, flags, it);
127 BIO_printf(out, "-----END %s-----\n", hdr);
128 return r;
129 }
130
b64_read_asn1(BIO * bio,const ASN1_ITEM * it)131 static ASN1_VALUE *b64_read_asn1(BIO *bio, const ASN1_ITEM *it)
132 {
133 BIO *b64;
134 ASN1_VALUE *val;
135
136 if ((b64 = BIO_new(BIO_f_base64())) == NULL) {
137 ASN1err(ASN1_F_B64_READ_ASN1, ERR_R_MALLOC_FAILURE);
138 return 0;
139 }
140 bio = BIO_push(b64, bio);
141 val = ASN1_item_d2i_bio(it, bio, NULL);
142 if (!val)
143 ASN1err(ASN1_F_B64_READ_ASN1, ASN1_R_DECODE_ERROR);
144 (void)BIO_flush(bio);
145 BIO_pop(bio);
146 BIO_free(b64);
147 return val;
148 }
149
150 /* Generate the MIME "micalg" parameter from RFC3851, RFC4490 */
151
asn1_write_micalg(BIO * out,STACK_OF (X509_ALGOR)* mdalgs)152 static int asn1_write_micalg(BIO *out, STACK_OF(X509_ALGOR) *mdalgs)
153 {
154 const EVP_MD *md;
155 int i, have_unknown = 0, write_comma, ret = 0, md_nid;
156 have_unknown = 0;
157 write_comma = 0;
158 for (i = 0; i < sk_X509_ALGOR_num(mdalgs); i++) {
159 if (write_comma)
160 BIO_write(out, ",", 1);
161 write_comma = 1;
162 md_nid = OBJ_obj2nid(sk_X509_ALGOR_value(mdalgs, i)->algorithm);
163 md = EVP_get_digestbynid(md_nid);
164 if (md && md->md_ctrl) {
165 int rv;
166 char *micstr;
167 rv = md->md_ctrl(NULL, EVP_MD_CTRL_MICALG, 0, &micstr);
168 if (rv > 0) {
169 BIO_puts(out, micstr);
170 OPENSSL_free(micstr);
171 continue;
172 }
173 if (rv != -2)
174 goto err;
175 }
176 switch (md_nid) {
177 case NID_sha1:
178 BIO_puts(out, "sha1");
179 break;
180
181 case NID_md5:
182 BIO_puts(out, "md5");
183 break;
184
185 case NID_sha256:
186 BIO_puts(out, "sha-256");
187 break;
188
189 case NID_sha384:
190 BIO_puts(out, "sha-384");
191 break;
192
193 case NID_sha512:
194 BIO_puts(out, "sha-512");
195 break;
196
197 case NID_id_GostR3411_94:
198 BIO_puts(out, "gostr3411-94");
199 goto err;
200
201 case NID_id_GostR3411_2012_256:
202 BIO_puts(out, "gostr3411-2012-256");
203 goto err;
204
205 case NID_id_GostR3411_2012_512:
206 BIO_puts(out, "gostr3411-2012-512");
207 goto err;
208
209 default:
210 if (have_unknown)
211 write_comma = 0;
212 else {
213 BIO_puts(out, "unknown");
214 have_unknown = 1;
215 }
216 break;
217
218 }
219 }
220
221 ret = 1;
222 err:
223
224 return ret;
225
226 }
227
228 /* SMIME sender */
229
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)230 int SMIME_write_ASN1(BIO *bio, ASN1_VALUE *val, BIO *data, int flags,
231 int ctype_nid, int econt_nid,
232 STACK_OF(X509_ALGOR) *mdalgs, const ASN1_ITEM *it)
233 {
234 char bound[33], c;
235 int i;
236 const char *mime_prefix, *mime_eol, *cname = "smime.p7m";
237 const char *msg_type = NULL;
238 if (flags & SMIME_OLDMIME)
239 mime_prefix = "application/x-pkcs7-";
240 else
241 mime_prefix = "application/pkcs7-";
242
243 if (flags & SMIME_CRLFEOL)
244 mime_eol = "\r\n";
245 else
246 mime_eol = "\n";
247 if ((flags & SMIME_DETACHED) && data) {
248 /* We want multipart/signed */
249 /* Generate a random boundary */
250 if (RAND_bytes((unsigned char *)bound, 32) <= 0)
251 return 0;
252 for (i = 0; i < 32; i++) {
253 c = bound[i] & 0xf;
254 if (c < 10)
255 c += '0';
256 else
257 c += 'A' - 10;
258 bound[i] = c;
259 }
260 bound[32] = 0;
261 BIO_printf(bio, "MIME-Version: 1.0%s", mime_eol);
262 BIO_printf(bio, "Content-Type: multipart/signed;");
263 BIO_printf(bio, " protocol=\"%ssignature\";", mime_prefix);
264 BIO_puts(bio, " micalg=\"");
265 asn1_write_micalg(bio, mdalgs);
266 BIO_printf(bio, "\"; boundary=\"----%s\"%s%s",
267 bound, mime_eol, mime_eol);
268 BIO_printf(bio, "This is an S/MIME signed message%s%s",
269 mime_eol, mime_eol);
270 /* Now write out the first part */
271 BIO_printf(bio, "------%s%s", bound, mime_eol);
272 if (!asn1_output_data(bio, data, val, flags, it))
273 return 0;
274 BIO_printf(bio, "%s------%s%s", mime_eol, bound, mime_eol);
275
276 /* Headers for signature */
277
278 BIO_printf(bio, "Content-Type: %ssignature;", mime_prefix);
279 BIO_printf(bio, " name=\"smime.p7s\"%s", mime_eol);
280 BIO_printf(bio, "Content-Transfer-Encoding: base64%s", mime_eol);
281 BIO_printf(bio, "Content-Disposition: attachment;");
282 BIO_printf(bio, " filename=\"smime.p7s\"%s%s", mime_eol, mime_eol);
283 B64_write_ASN1(bio, val, NULL, 0, it);
284 BIO_printf(bio, "%s------%s--%s%s", mime_eol, bound,
285 mime_eol, mime_eol);
286 return 1;
287 }
288
289 /* Determine smime-type header */
290
291 if (ctype_nid == NID_pkcs7_enveloped)
292 msg_type = "enveloped-data";
293 else if (ctype_nid == NID_pkcs7_signed) {
294 if (econt_nid == NID_id_smime_ct_receipt)
295 msg_type = "signed-receipt";
296 else if (sk_X509_ALGOR_num(mdalgs) >= 0)
297 msg_type = "signed-data";
298 else
299 msg_type = "certs-only";
300 } else if (ctype_nid == NID_id_smime_ct_compressedData) {
301 msg_type = "compressed-data";
302 cname = "smime.p7z";
303 }
304 /* MIME headers */
305 BIO_printf(bio, "MIME-Version: 1.0%s", mime_eol);
306 BIO_printf(bio, "Content-Disposition: attachment;");
307 BIO_printf(bio, " filename=\"%s\"%s", cname, mime_eol);
308 BIO_printf(bio, "Content-Type: %smime;", mime_prefix);
309 if (msg_type)
310 BIO_printf(bio, " smime-type=%s;", msg_type);
311 BIO_printf(bio, " name=\"%s\"%s", cname, mime_eol);
312 BIO_printf(bio, "Content-Transfer-Encoding: base64%s%s",
313 mime_eol, mime_eol);
314 if (!B64_write_ASN1(bio, val, data, flags, it))
315 return 0;
316 BIO_printf(bio, "%s", mime_eol);
317 return 1;
318 }
319
320 /* Handle output of ASN1 data */
321
asn1_output_data(BIO * out,BIO * data,ASN1_VALUE * val,int flags,const ASN1_ITEM * it)322 static int asn1_output_data(BIO *out, BIO *data, ASN1_VALUE *val, int flags,
323 const ASN1_ITEM *it)
324 {
325 BIO *tmpbio;
326 const ASN1_AUX *aux = it->funcs;
327 ASN1_STREAM_ARG sarg;
328 int rv = 1;
329
330 /*
331 * If data is not detached or resigning then the output BIO is already
332 * set up to finalise when it is written through.
333 */
334 if (!(flags & SMIME_DETACHED) || (flags & PKCS7_REUSE_DIGEST)) {
335 SMIME_crlf_copy(data, out, flags);
336 return 1;
337 }
338
339 if (!aux || !aux->asn1_cb) {
340 ASN1err(ASN1_F_ASN1_OUTPUT_DATA, ASN1_R_STREAMING_NOT_SUPPORTED);
341 return 0;
342 }
343
344 sarg.out = out;
345 sarg.ndef_bio = NULL;
346 sarg.boundary = NULL;
347
348 /* Let ASN1 code prepend any needed BIOs */
349
350 if (aux->asn1_cb(ASN1_OP_DETACHED_PRE, &val, it, &sarg) <= 0)
351 return 0;
352
353 /* Copy data across, passing through filter BIOs for processing */
354 SMIME_crlf_copy(data, sarg.ndef_bio, flags);
355
356 /* Finalize structure */
357 if (aux->asn1_cb(ASN1_OP_DETACHED_POST, &val, it, &sarg) <= 0)
358 rv = 0;
359
360 /* Now remove any digests prepended to the BIO */
361
362 while (sarg.ndef_bio != out) {
363 tmpbio = BIO_pop(sarg.ndef_bio);
364 BIO_free(sarg.ndef_bio);
365 sarg.ndef_bio = tmpbio;
366 }
367
368 return rv;
369
370 }
371
372 /*
373 * SMIME reader: handle multipart/signed and opaque signing. in multipart
374 * case the content is placed in a memory BIO pointed to by "bcont". In
375 * opaque this is set to NULL
376 */
377
SMIME_read_ASN1(BIO * bio,BIO ** bcont,const ASN1_ITEM * it)378 ASN1_VALUE *SMIME_read_ASN1(BIO *bio, BIO **bcont, const ASN1_ITEM *it)
379 {
380 BIO *asnin;
381 STACK_OF(MIME_HEADER) *headers = NULL;
382 STACK_OF(BIO) *parts = NULL;
383 MIME_HEADER *hdr;
384 MIME_PARAM *prm;
385 ASN1_VALUE *val;
386 int ret;
387
388 if (bcont)
389 *bcont = NULL;
390
391 if ((headers = mime_parse_hdr(bio)) == NULL) {
392 ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_MIME_PARSE_ERROR);
393 return NULL;
394 }
395
396 if ((hdr = mime_hdr_find(headers, "content-type")) == NULL
397 || hdr->value == NULL) {
398 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
399 ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_NO_CONTENT_TYPE);
400 return NULL;
401 }
402
403 /* Handle multipart/signed */
404
405 if (strcmp(hdr->value, "multipart/signed") == 0) {
406 /* Split into two parts */
407 prm = mime_param_find(hdr, "boundary");
408 if (!prm || !prm->param_value) {
409 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
410 ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_NO_MULTIPART_BOUNDARY);
411 return NULL;
412 }
413 ret = multi_split(bio, prm->param_value, &parts);
414 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
415 if (!ret || (sk_BIO_num(parts) != 2)) {
416 ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_NO_MULTIPART_BODY_FAILURE);
417 sk_BIO_pop_free(parts, BIO_vfree);
418 return NULL;
419 }
420
421 /* Parse the signature piece */
422 asnin = sk_BIO_value(parts, 1);
423
424 if ((headers = mime_parse_hdr(asnin)) == NULL) {
425 ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_MIME_SIG_PARSE_ERROR);
426 sk_BIO_pop_free(parts, BIO_vfree);
427 return NULL;
428 }
429
430 /* Get content type */
431
432 if ((hdr = mime_hdr_find(headers, "content-type")) == NULL
433 || hdr->value == NULL) {
434 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
435 ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_NO_SIG_CONTENT_TYPE);
436 sk_BIO_pop_free(parts, BIO_vfree);
437 return NULL;
438 }
439
440 if (strcmp(hdr->value, "application/x-pkcs7-signature") &&
441 strcmp(hdr->value, "application/pkcs7-signature")) {
442 ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_SIG_INVALID_MIME_TYPE);
443 ERR_add_error_data(2, "type: ", hdr->value);
444 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
445 sk_BIO_pop_free(parts, BIO_vfree);
446 return NULL;
447 }
448 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
449 /* Read in ASN1 */
450 if ((val = b64_read_asn1(asnin, it)) == NULL) {
451 ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_ASN1_SIG_PARSE_ERROR);
452 sk_BIO_pop_free(parts, BIO_vfree);
453 return NULL;
454 }
455
456 if (bcont) {
457 *bcont = sk_BIO_value(parts, 0);
458 BIO_free(asnin);
459 sk_BIO_free(parts);
460 } else
461 sk_BIO_pop_free(parts, BIO_vfree);
462 return val;
463 }
464
465 /* OK, if not multipart/signed try opaque signature */
466
467 if (strcmp(hdr->value, "application/x-pkcs7-mime") &&
468 strcmp(hdr->value, "application/pkcs7-mime")) {
469 ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_INVALID_MIME_TYPE);
470 ERR_add_error_data(2, "type: ", hdr->value);
471 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
472 return NULL;
473 }
474
475 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
476
477 if ((val = b64_read_asn1(bio, it)) == NULL) {
478 ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_ASN1_PARSE_ERROR);
479 return NULL;
480 }
481 return val;
482
483 }
484
485 /* Copy text from one BIO to another making the output CRLF at EOL */
SMIME_crlf_copy(BIO * in,BIO * out,int flags)486 int SMIME_crlf_copy(BIO *in, BIO *out, int flags)
487 {
488 BIO *bf;
489 char eol;
490 int len;
491 char linebuf[MAX_SMLEN];
492 /*
493 * Buffer output so we don't write one line at a time. This is useful
494 * when streaming as we don't end up with one OCTET STRING per line.
495 */
496 bf = BIO_new(BIO_f_buffer());
497 if (bf == NULL)
498 return 0;
499 out = BIO_push(bf, out);
500 if (flags & SMIME_BINARY) {
501 while ((len = BIO_read(in, linebuf, MAX_SMLEN)) > 0)
502 BIO_write(out, linebuf, len);
503 } else {
504 int eolcnt = 0;
505 if (flags & SMIME_TEXT)
506 BIO_printf(out, "Content-Type: text/plain\r\n\r\n");
507 while ((len = BIO_gets(in, linebuf, MAX_SMLEN)) > 0) {
508 eol = strip_eol(linebuf, &len, flags);
509 if (len) {
510 /* Not EOF: write out all CRLF */
511 if (flags & SMIME_ASCIICRLF) {
512 int i;
513 for (i = 0; i < eolcnt; i++)
514 BIO_write(out, "\r\n", 2);
515 eolcnt = 0;
516 }
517 BIO_write(out, linebuf, len);
518 if (eol)
519 BIO_write(out, "\r\n", 2);
520 } else if (flags & SMIME_ASCIICRLF)
521 eolcnt++;
522 else if (eol)
523 BIO_write(out, "\r\n", 2);
524 }
525 }
526 (void)BIO_flush(out);
527 BIO_pop(out);
528 BIO_free(bf);
529 return 1;
530 }
531
532 /* Strip off headers if they are text/plain */
SMIME_text(BIO * in,BIO * out)533 int SMIME_text(BIO *in, BIO *out)
534 {
535 char iobuf[4096];
536 int len;
537 STACK_OF(MIME_HEADER) *headers;
538 MIME_HEADER *hdr;
539
540 if ((headers = mime_parse_hdr(in)) == NULL) {
541 ASN1err(ASN1_F_SMIME_TEXT, ASN1_R_MIME_PARSE_ERROR);
542 return 0;
543 }
544 if ((hdr = mime_hdr_find(headers, "content-type")) == NULL
545 || hdr->value == NULL) {
546 ASN1err(ASN1_F_SMIME_TEXT, ASN1_R_MIME_NO_CONTENT_TYPE);
547 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
548 return 0;
549 }
550 if (strcmp(hdr->value, "text/plain")) {
551 ASN1err(ASN1_F_SMIME_TEXT, ASN1_R_INVALID_MIME_TYPE);
552 ERR_add_error_data(2, "type: ", hdr->value);
553 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
554 return 0;
555 }
556 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
557 while ((len = BIO_read(in, iobuf, sizeof(iobuf))) > 0)
558 BIO_write(out, iobuf, len);
559 if (len < 0)
560 return 0;
561 return 1;
562 }
563
564 /*
565 * Split a multipart/XXX message body into component parts: result is
566 * canonical parts in a STACK of bios
567 */
568
multi_split(BIO * bio,const char * bound,STACK_OF (BIO)** ret)569 static int multi_split(BIO *bio, const char *bound, STACK_OF(BIO) **ret)
570 {
571 char linebuf[MAX_SMLEN];
572 int len, blen;
573 int eol = 0, next_eol = 0;
574 BIO *bpart = NULL;
575 STACK_OF(BIO) *parts;
576 char state, part, first;
577
578 blen = strlen(bound);
579 part = 0;
580 state = 0;
581 first = 1;
582 parts = sk_BIO_new_null();
583 *ret = parts;
584 if (*ret == NULL)
585 return 0;
586 while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) {
587 state = mime_bound_check(linebuf, len, bound, blen);
588 if (state == 1) {
589 first = 1;
590 part++;
591 } else if (state == 2) {
592 if (!sk_BIO_push(parts, bpart)) {
593 BIO_free(bpart);
594 return 0;
595 }
596 return 1;
597 } else if (part) {
598 /* Strip CR+LF from linebuf */
599 next_eol = strip_eol(linebuf, &len, 0);
600 if (first) {
601 first = 0;
602 if (bpart)
603 if (!sk_BIO_push(parts, bpart)) {
604 BIO_free(bpart);
605 return 0;
606 }
607 bpart = BIO_new(BIO_s_mem());
608 if (bpart == NULL)
609 return 0;
610 BIO_set_mem_eof_return(bpart, 0);
611 } else if (eol)
612 BIO_write(bpart, "\r\n", 2);
613 eol = next_eol;
614 if (len)
615 BIO_write(bpart, linebuf, len);
616 }
617 }
618 BIO_free(bpart);
619 return 0;
620 }
621
622 /* This is the big one: parse MIME header lines up to message body */
623
624 #define MIME_INVALID 0
625 #define MIME_START 1
626 #define MIME_TYPE 2
627 #define MIME_NAME 3
628 #define MIME_VALUE 4
629 #define MIME_QUOTE 5
630 #define MIME_COMMENT 6
631
STACK_OF(MIME_HEADER)632 static STACK_OF(MIME_HEADER) *mime_parse_hdr(BIO *bio)
633 {
634 char *p, *q, c;
635 char *ntmp;
636 char linebuf[MAX_SMLEN];
637 MIME_HEADER *mhdr = NULL, *new_hdr = NULL;
638 STACK_OF(MIME_HEADER) *headers;
639 int len, state, save_state = 0;
640
641 headers = sk_MIME_HEADER_new(mime_hdr_cmp);
642 if (headers == NULL)
643 return NULL;
644 while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) {
645 /* If whitespace at line start then continuation line */
646 if (mhdr && ossl_isspace(linebuf[0]))
647 state = MIME_NAME;
648 else
649 state = MIME_START;
650 ntmp = NULL;
651 /* Go through all characters */
652 for (p = linebuf, q = linebuf; (c = *p) && (c != '\r') && (c != '\n');
653 p++) {
654
655 /*
656 * State machine to handle MIME headers if this looks horrible
657 * that's because it *is*
658 */
659
660 switch (state) {
661 case MIME_START:
662 if (c == ':') {
663 state = MIME_TYPE;
664 *p = 0;
665 ntmp = strip_ends(q);
666 q = p + 1;
667 }
668 break;
669
670 case MIME_TYPE:
671 if (c == ';') {
672 mime_debug("Found End Value\n");
673 *p = 0;
674 new_hdr = mime_hdr_new(ntmp, strip_ends(q));
675 if (new_hdr == NULL)
676 goto err;
677 if (!sk_MIME_HEADER_push(headers, new_hdr))
678 goto err;
679 mhdr = new_hdr;
680 new_hdr = NULL;
681 ntmp = NULL;
682 q = p + 1;
683 state = MIME_NAME;
684 } else if (c == '(') {
685 save_state = state;
686 state = MIME_COMMENT;
687 }
688 break;
689
690 case MIME_COMMENT:
691 if (c == ')') {
692 state = save_state;
693 }
694 break;
695
696 case MIME_NAME:
697 if (c == '=') {
698 state = MIME_VALUE;
699 *p = 0;
700 ntmp = strip_ends(q);
701 q = p + 1;
702 }
703 break;
704
705 case MIME_VALUE:
706 if (c == ';') {
707 state = MIME_NAME;
708 *p = 0;
709 mime_hdr_addparam(mhdr, ntmp, strip_ends(q));
710 ntmp = NULL;
711 q = p + 1;
712 } else if (c == '"') {
713 mime_debug("Found Quote\n");
714 state = MIME_QUOTE;
715 } else if (c == '(') {
716 save_state = state;
717 state = MIME_COMMENT;
718 }
719 break;
720
721 case MIME_QUOTE:
722 if (c == '"') {
723 mime_debug("Found Match Quote\n");
724 state = MIME_VALUE;
725 }
726 break;
727 }
728 }
729
730 if (state == MIME_TYPE) {
731 new_hdr = mime_hdr_new(ntmp, strip_ends(q));
732 if (new_hdr == NULL)
733 goto err;
734 if (!sk_MIME_HEADER_push(headers, new_hdr))
735 goto err;
736 mhdr = new_hdr;
737 new_hdr = NULL;
738 } else if (state == MIME_VALUE)
739 mime_hdr_addparam(mhdr, ntmp, strip_ends(q));
740 if (p == linebuf)
741 break; /* Blank line means end of headers */
742 }
743
744 return headers;
745
746 err:
747 mime_hdr_free(new_hdr);
748 sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
749 return NULL;
750 }
751
strip_ends(char * name)752 static char *strip_ends(char *name)
753 {
754 return strip_end(strip_start(name));
755 }
756
757 /* Strip a parameter of whitespace from start of param */
strip_start(char * name)758 static char *strip_start(char *name)
759 {
760 char *p, c;
761 /* Look for first non white space or quote */
762 for (p = name; (c = *p); p++) {
763 if (c == '"') {
764 /* Next char is start of string if non null */
765 if (p[1])
766 return p + 1;
767 /* Else null string */
768 return NULL;
769 }
770 if (!ossl_isspace(c))
771 return p;
772 }
773 return NULL;
774 }
775
776 /* As above but strip from end of string : maybe should handle brackets? */
strip_end(char * name)777 static char *strip_end(char *name)
778 {
779 char *p, c;
780 if (!name)
781 return NULL;
782 /* Look for first non white space or quote */
783 for (p = name + strlen(name) - 1; p >= name; p--) {
784 c = *p;
785 if (c == '"') {
786 if (p - 1 == name)
787 return NULL;
788 *p = 0;
789 return name;
790 }
791 if (ossl_isspace(c))
792 *p = 0;
793 else
794 return name;
795 }
796 return NULL;
797 }
798
mime_hdr_new(const char * name,const char * value)799 static MIME_HEADER *mime_hdr_new(const char *name, const char *value)
800 {
801 MIME_HEADER *mhdr = NULL;
802 char *tmpname = NULL, *tmpval = NULL, *p;
803
804 if (name) {
805 if ((tmpname = OPENSSL_strdup(name)) == NULL)
806 return NULL;
807 for (p = tmpname; *p; p++)
808 *p = ossl_tolower(*p);
809 }
810 if (value) {
811 if ((tmpval = OPENSSL_strdup(value)) == NULL)
812 goto err;
813 for (p = tmpval; *p; p++)
814 *p = ossl_tolower(*p);
815 }
816 mhdr = OPENSSL_malloc(sizeof(*mhdr));
817 if (mhdr == NULL)
818 goto err;
819 mhdr->name = tmpname;
820 mhdr->value = tmpval;
821 if ((mhdr->params = sk_MIME_PARAM_new(mime_param_cmp)) == NULL)
822 goto err;
823 return mhdr;
824
825 err:
826 OPENSSL_free(tmpname);
827 OPENSSL_free(tmpval);
828 OPENSSL_free(mhdr);
829 return NULL;
830 }
831
mime_hdr_addparam(MIME_HEADER * mhdr,const char * name,const char * value)832 static int mime_hdr_addparam(MIME_HEADER *mhdr, const char *name, const char *value)
833 {
834 char *tmpname = NULL, *tmpval = NULL, *p;
835 MIME_PARAM *mparam = NULL;
836
837 if (name) {
838 tmpname = OPENSSL_strdup(name);
839 if (!tmpname)
840 goto err;
841 for (p = tmpname; *p; p++)
842 *p = ossl_tolower(*p);
843 }
844 if (value) {
845 tmpval = OPENSSL_strdup(value);
846 if (!tmpval)
847 goto err;
848 }
849 /* Parameter values are case sensitive so leave as is */
850 mparam = OPENSSL_malloc(sizeof(*mparam));
851 if (mparam == NULL)
852 goto err;
853 mparam->param_name = tmpname;
854 mparam->param_value = tmpval;
855 if (!sk_MIME_PARAM_push(mhdr->params, mparam))
856 goto err;
857 return 1;
858 err:
859 OPENSSL_free(tmpname);
860 OPENSSL_free(tmpval);
861 OPENSSL_free(mparam);
862 return 0;
863 }
864
mime_hdr_cmp(const MIME_HEADER * const * a,const MIME_HEADER * const * b)865 static int mime_hdr_cmp(const MIME_HEADER *const *a,
866 const MIME_HEADER *const *b)
867 {
868 if (!(*a)->name || !(*b)->name)
869 return ! !(*a)->name - ! !(*b)->name;
870
871 return strcmp((*a)->name, (*b)->name);
872 }
873
mime_param_cmp(const MIME_PARAM * const * a,const MIME_PARAM * const * b)874 static int mime_param_cmp(const MIME_PARAM *const *a,
875 const MIME_PARAM *const *b)
876 {
877 if (!(*a)->param_name || !(*b)->param_name)
878 return ! !(*a)->param_name - ! !(*b)->param_name;
879 return strcmp((*a)->param_name, (*b)->param_name);
880 }
881
882 /* Find a header with a given name (if possible) */
883
mime_hdr_find(STACK_OF (MIME_HEADER)* hdrs,const char * name)884 static MIME_HEADER *mime_hdr_find(STACK_OF(MIME_HEADER) *hdrs, const char *name)
885 {
886 MIME_HEADER htmp;
887 int idx;
888
889 htmp.name = (char *)name;
890 htmp.value = NULL;
891 htmp.params = NULL;
892
893 idx = sk_MIME_HEADER_find(hdrs, &htmp);
894 return sk_MIME_HEADER_value(hdrs, idx);
895 }
896
mime_param_find(MIME_HEADER * hdr,const char * name)897 static MIME_PARAM *mime_param_find(MIME_HEADER *hdr, const char *name)
898 {
899 MIME_PARAM param;
900 int idx;
901
902 param.param_name = (char *)name;
903 param.param_value = NULL;
904 idx = sk_MIME_PARAM_find(hdr->params, ¶m);
905 return sk_MIME_PARAM_value(hdr->params, idx);
906 }
907
mime_hdr_free(MIME_HEADER * hdr)908 static void mime_hdr_free(MIME_HEADER *hdr)
909 {
910 if (hdr == NULL)
911 return;
912 OPENSSL_free(hdr->name);
913 OPENSSL_free(hdr->value);
914 if (hdr->params)
915 sk_MIME_PARAM_pop_free(hdr->params, mime_param_free);
916 OPENSSL_free(hdr);
917 }
918
mime_param_free(MIME_PARAM * param)919 static void mime_param_free(MIME_PARAM *param)
920 {
921 OPENSSL_free(param->param_name);
922 OPENSSL_free(param->param_value);
923 OPENSSL_free(param);
924 }
925
926 /*-
927 * Check for a multipart boundary. Returns:
928 * 0 : no boundary
929 * 1 : part boundary
930 * 2 : final boundary
931 */
mime_bound_check(char * line,int linelen,const char * bound,int blen)932 static int mime_bound_check(char *line, int linelen, const char *bound, int blen)
933 {
934 if (linelen == -1)
935 linelen = strlen(line);
936 if (blen == -1)
937 blen = strlen(bound);
938 /* Quickly eliminate if line length too short */
939 if (blen + 2 > linelen)
940 return 0;
941 /* Check for part boundary */
942 if ((strncmp(line, "--", 2) == 0)
943 && strncmp(line + 2, bound, blen) == 0) {
944 if (strncmp(line + blen + 2, "--", 2) == 0)
945 return 2;
946 else
947 return 1;
948 }
949 return 0;
950 }
951
strip_eol(char * linebuf,int * plen,int flags)952 static int strip_eol(char *linebuf, int *plen, int flags)
953 {
954 int len = *plen;
955 char *p, c;
956 int is_eol = 0;
957
958 for (p = linebuf + len - 1; len > 0; len--, p--) {
959 c = *p;
960 if (c == '\n') {
961 is_eol = 1;
962 } else if (is_eol && flags & SMIME_ASCIICRLF && c == 32) {
963 /* Strip trailing space on a line; 32 == ASCII for ' ' */
964 continue;
965 } else if (c != '\r') {
966 break;
967 }
968 }
969 *plen = len;
970 return is_eol;
971 }
972