8241c8bf106a0fe9cb993db78bce88d722244693
[claws.git] / src / plugins / pgpmime / pgpmime.c
1 /*
2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
3  * Copyright (C) 1999-2003 Hiroyuki Yamamoto & the Sylpheed-Claws team
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18  */
19
20 #ifdef HAVE_CONFIG_H
21 #  include "config.h"
22 #endif
23
24 #ifdef USE_GPGME
25
26 #include "defs.h"
27 #include <glib.h>
28 #include <gpgme.h>
29 #include <ctype.h>
30
31 #include "utils.h"
32 #include "privacy.h"
33 #include "procmime.h"
34
35 #include "pgpmime.h"
36 #include <plugins/pgpcore/sgpgme.h>
37 #include <plugins/pgpcore/prefs_gpg.h>
38 #include <plugins/pgpcore/passphrase.h>
39
40 #include "prefs_common.h"
41
42 typedef struct _PrivacyDataPGP PrivacyDataPGP;
43
44 struct _PrivacyDataPGP
45 {
46         PrivacyData     data;
47         
48         gboolean        done_sigtest;
49         gboolean        is_signed;
50         gpgme_verify_result_t   sigstatus;
51         gpgme_ctx_t     ctx;
52         gboolean        is_pkcs7;
53 };
54
55 static PrivacySystem pgpmime_system;
56
57 static gint pgpmime_check_signature(MimeInfo *mimeinfo);
58
59 static PrivacyDataPGP *pgpmime_new_privacydata()
60 {
61         PrivacyDataPGP *data;
62
63         data = g_new0(PrivacyDataPGP, 1);
64         data->data.system = &pgpmime_system;
65         data->done_sigtest = FALSE;
66         data->is_signed = FALSE;
67         data->sigstatus = NULL;
68         gpgme_new(&data->ctx);
69         
70         return data;
71 }
72
73 static void pgpmime_free_privacydata(PrivacyData *_data)
74 {
75         PrivacyDataPGP *data = (PrivacyDataPGP *) _data;
76         gpgme_release(data->ctx);
77         g_free(data);
78 }
79
80 static gboolean pgpmime_is_signed(MimeInfo *mimeinfo)
81 {
82         MimeInfo *parent;
83         MimeInfo *signature;
84         const gchar *protocol;
85         PrivacyDataPGP *data = NULL;
86         
87         g_return_val_if_fail(mimeinfo != NULL, FALSE);
88         if (mimeinfo->privacy != NULL) {
89                 data = (PrivacyDataPGP *) mimeinfo->privacy;
90                 if (data->done_sigtest)
91                         return data->is_signed;
92         }
93         
94         /* check parent */
95         parent = procmime_mimeinfo_parent(mimeinfo);
96         if (parent == NULL)
97                 return FALSE;
98         if ((parent->type != MIMETYPE_MULTIPART) ||
99             g_ascii_strcasecmp(parent->subtype, "signed"))
100                 return FALSE;
101         protocol = procmime_mimeinfo_get_parameter(parent, "protocol");
102         if ((protocol == NULL) || 
103             (g_ascii_strcasecmp(protocol, "application/pgp-signature") &&
104              g_ascii_strcasecmp(protocol, "application/pkcs7-signature") &&
105              g_ascii_strcasecmp(protocol, "application/x-pkcs7-signature")))
106                 return FALSE;
107
108         /* check if mimeinfo is the first child */
109         if (parent->node->children->data != mimeinfo)
110                 return FALSE;
111
112         /* check signature */
113         signature = parent->node->children->next != NULL ? 
114             (MimeInfo *) parent->node->children->next->data : NULL;
115         if (signature == NULL)
116                 return FALSE;
117         if ((signature->type != MIMETYPE_APPLICATION) ||
118             (g_ascii_strcasecmp(signature->subtype, "pgp-signature") &&
119              g_ascii_strcasecmp(signature->subtype, "pkcs7-signature") &&
120              g_ascii_strcasecmp(signature->subtype, "x-pkcs7-signature")))
121                 return FALSE;
122
123         if (data == NULL) {
124                 data = pgpmime_new_privacydata();
125                 mimeinfo->privacy = (PrivacyData *) data;
126         }
127         
128         if (!g_ascii_strcasecmp(signature->subtype, "pkcs7-signature") ||
129             !g_ascii_strcasecmp(signature->subtype, "x-pkcs7-signature"))
130                 data->is_pkcs7 = TRUE;
131         else
132                 data->is_pkcs7 = FALSE;
133
134         data->done_sigtest = TRUE;
135         data->is_signed = TRUE;
136
137         return TRUE;
138 }
139
140 static gchar *get_canonical_content(FILE *fp, const gchar *boundary)
141 {
142         gchar *ret;
143         GString *textbuffer;
144         guint boundary_len;
145         gchar buf[BUFFSIZE];
146
147         boundary_len = strlen(boundary);
148         while (fgets(buf, sizeof(buf), fp) != NULL)
149                 if (IS_BOUNDARY(buf, boundary, boundary_len))
150                         break;
151
152         textbuffer = g_string_new("");
153         while (fgets(buf, sizeof(buf), fp) != NULL) {
154                 gchar *buf2;
155
156                 if (IS_BOUNDARY(buf, boundary, boundary_len))
157                         break;
158                 
159                 buf2 = canonicalize_str(buf);
160                 g_string_append(textbuffer, buf2);
161                 g_free(buf2);
162         }
163         g_string_truncate(textbuffer, textbuffer->len - 2);
164                 
165         ret = textbuffer->str;
166         g_string_free(textbuffer, FALSE);
167
168         return ret;
169 }
170
171 static gint pgpmime_check_signature(MimeInfo *mimeinfo)
172 {
173         PrivacyDataPGP *data;
174         MimeInfo *parent, *signature;
175         FILE *fp;
176         gchar *boundary;
177         gchar *textstr;
178         gpgme_data_t sigdata = NULL, textdata = NULL;
179         gpgme_error_t err;
180         g_return_val_if_fail(mimeinfo != NULL, -1);
181         g_return_val_if_fail(mimeinfo->privacy != NULL, -1);
182         data = (PrivacyDataPGP *) mimeinfo->privacy;
183         gpgme_new(&data->ctx);
184         
185         debug_print("Checking %s/MIME signature\n", data->is_pkcs7?"S":"PGP");
186
187         if (data->is_pkcs7) {
188                 err = gpgme_set_protocol(data->ctx, GPGME_PROTOCOL_CMS);
189         } else
190                 err = gpgme_set_protocol(data->ctx, GPGME_PROTOCOL_OpenPGP);
191
192         if (err) {
193                 debug_print ("gpgme_set_protocol failed: %s\n",
194                    gpgme_strerror (err));
195         }
196         parent = procmime_mimeinfo_parent(mimeinfo);
197
198         fp = g_fopen(parent->data.filename, "rb");
199         g_return_val_if_fail(fp != NULL, SIGNATURE_INVALID);
200         
201         boundary = g_hash_table_lookup(parent->typeparameters, "boundary");
202         if (!boundary)
203                 return 0;
204
205         textstr = get_canonical_content(fp, boundary);
206
207         err = gpgme_data_new_from_mem(&textdata, textstr, strlen(textstr), 0);
208         if (err) {
209                 debug_print ("gpgme_data_new_from_mem failed: %s\n",
210                    gpgme_strerror (err));
211         }
212         signature = (MimeInfo *) mimeinfo->node->next->data;
213         sigdata = sgpgme_data_from_mimeinfo(signature);
214
215         err = 0;
216         if (signature->encoding_type == ENC_BASE64) {
217                 err = gpgme_data_set_encoding (sigdata, GPGME_DATA_ENCODING_BASE64);
218         }
219         
220         if (err) {
221                 debug_print ("gpgme_data_set_encoding failed: %s\n",
222                         gpgme_strerror (err));
223         }
224
225         data->sigstatus =
226                 sgpgme_verify_signature (data->ctx, sigdata, textdata, NULL);
227
228         gpgme_data_release(sigdata);
229         gpgme_data_release(textdata);
230         g_free(textstr);
231         fclose(fp);
232         
233         return 0;
234 }
235
236 static SignatureStatus pgpmime_get_sig_status(MimeInfo *mimeinfo)
237 {
238         PrivacyDataPGP *data = (PrivacyDataPGP *) mimeinfo->privacy;
239         
240         g_return_val_if_fail(data != NULL, SIGNATURE_INVALID);
241
242         if (data->sigstatus == NULL && 
243             prefs_gpg_get_config()->auto_check_signatures)
244                 pgpmime_check_signature(mimeinfo);
245         
246         return sgpgme_sigstat_gpgme_to_privacy(data->ctx, data->sigstatus);
247 }
248
249 static gchar *pgpmime_get_sig_info_short(MimeInfo *mimeinfo)
250 {
251         PrivacyDataPGP *data = (PrivacyDataPGP *) mimeinfo->privacy;
252         
253         g_return_val_if_fail(data != NULL, g_strdup("Error"));
254
255         if (data->sigstatus == NULL && 
256             prefs_gpg_get_config()->auto_check_signatures)
257                 pgpmime_check_signature(mimeinfo);
258         
259         return sgpgme_sigstat_info_short(data->ctx, data->sigstatus);
260 }
261
262 static gchar *pgpmime_get_sig_info_full(MimeInfo *mimeinfo)
263 {
264         PrivacyDataPGP *data = (PrivacyDataPGP *) mimeinfo->privacy;
265         
266         g_return_val_if_fail(data != NULL, g_strdup("Error"));
267
268         if (data->sigstatus == NULL && 
269             prefs_gpg_get_config()->auto_check_signatures)
270                 pgpmime_check_signature(mimeinfo);
271         
272         return sgpgme_sigstat_info_full(data->ctx, data->sigstatus);
273 }
274
275 static gboolean pgpmime_is_encrypted(MimeInfo *mimeinfo)
276 {
277         MimeInfo *tmpinfo;
278         const gchar *tmpstr;
279         
280         if (mimeinfo->type != MIMETYPE_MULTIPART)
281                 return FALSE;
282         if (g_ascii_strcasecmp(mimeinfo->subtype, "encrypted"))
283                 return FALSE;
284         tmpstr = procmime_mimeinfo_get_parameter(mimeinfo, "protocol");
285         if ((tmpstr == NULL) || g_ascii_strcasecmp(tmpstr, "application/pgp-encrypted"))
286                 return FALSE;
287         if (g_node_n_children(mimeinfo->node) != 2)
288                 return FALSE;
289         
290         tmpinfo = (MimeInfo *) g_node_nth_child(mimeinfo->node, 0)->data;
291         if (tmpinfo->type != MIMETYPE_APPLICATION)
292                 return FALSE;
293         if (g_ascii_strcasecmp(tmpinfo->subtype, "pgp-encrypted"))
294                 return FALSE;
295         
296         tmpinfo = (MimeInfo *) g_node_nth_child(mimeinfo->node, 1)->data;
297         if (tmpinfo->type != MIMETYPE_APPLICATION)
298                 return FALSE;
299         if (g_ascii_strcasecmp(tmpinfo->subtype, "octet-stream"))
300                 return FALSE;
301         
302         return TRUE;
303 }
304
305 static MimeInfo *pgpmime_decrypt(MimeInfo *mimeinfo)
306 {
307         MimeInfo *encinfo, *decinfo, *parseinfo;
308         gpgme_data_t cipher = NULL, plain = NULL;
309         static gint id = 0;
310         FILE *dstfp;
311         gchar *fname;
312         gpgme_verify_result_t sigstat = NULL;
313         PrivacyDataPGP *data = NULL;
314         gpgme_ctx_t ctx;
315         gchar *chars;
316         size_t len;
317
318         if (gpgme_new(&ctx) != GPG_ERR_NO_ERROR)
319                 return NULL;
320
321         
322         g_return_val_if_fail(pgpmime_is_encrypted(mimeinfo), NULL);
323         
324         encinfo = (MimeInfo *) g_node_nth_child(mimeinfo->node, 1)->data;
325
326         cipher = sgpgme_data_from_mimeinfo(encinfo);
327         plain = sgpgme_decrypt_verify(cipher, &sigstat, ctx);
328
329         gpgme_data_release(cipher);
330         if (plain == NULL) {
331                 debug_print("plain is null!\n");
332                 gpgme_release(ctx);
333                 return NULL;
334         }
335
336         fname = g_strdup_printf("%s%cplaintext.%08x",
337                 get_mime_tmp_dir(), G_DIR_SEPARATOR, ++id);
338
339         if ((dstfp = g_fopen(fname, "wb")) == NULL) {
340                 FILE_OP_ERROR(fname, "fopen");
341                 g_free(fname);
342                 gpgme_data_release(plain);
343                 gpgme_release(ctx);
344                 debug_print("can't open!\n");
345                 return NULL;
346         }
347
348         fprintf(dstfp, "MIME-Version: 1.0\n");
349
350         chars = gpgme_data_release_and_get_mem(plain, &len);
351         if (len > 0)
352                 fwrite(chars, len, 1, dstfp);
353         fclose(dstfp);
354
355         parseinfo = procmime_scan_file(fname);
356         g_free(fname);
357         if (parseinfo == NULL) {
358                 gpgme_release(ctx);
359                 return NULL;
360         }
361         decinfo = g_node_first_child(parseinfo->node) != NULL ?
362                 g_node_first_child(parseinfo->node)->data : NULL;
363         if (decinfo == NULL) {
364                 gpgme_release(ctx);
365                 return NULL;
366         }
367
368         g_node_unlink(decinfo->node);
369         procmime_mimeinfo_free_all(parseinfo);
370
371         decinfo->tmp = TRUE;
372
373         if (sigstat != NULL && sigstat->signatures != NULL) {
374                 if (decinfo->privacy != NULL) {
375                         data = (PrivacyDataPGP *) decinfo->privacy;
376                 } else {
377                         data = pgpmime_new_privacydata();
378                         decinfo->privacy = (PrivacyData *) data;        
379                 }
380                 data->done_sigtest = TRUE;
381                 data->is_signed = TRUE;
382                 data->sigstatus = sigstat;
383                 if (data->ctx)
384                         gpgme_release(data->ctx);
385                 data->ctx = ctx;
386         } else
387                 gpgme_release(ctx);
388
389         return decinfo;
390 }
391
392 gboolean pgpmime_sign(MimeInfo *mimeinfo, PrefsAccount *account)
393 {
394         MimeInfo *msgcontent, *sigmultipart, *newinfo;
395         gchar *textstr, *micalg;
396         FILE *fp;
397         gchar *boundary, *sigcontent;
398         gpgme_ctx_t ctx;
399         gpgme_data_t gpgtext, gpgsig;
400         size_t len;
401         struct passphrase_cb_info_s info;
402         gpgme_sign_result_t result = NULL;
403
404         memset (&info, 0, sizeof info);
405
406         /* remove content node from message */
407         msgcontent = (MimeInfo *) mimeinfo->node->children->data;
408         g_node_unlink(msgcontent->node);
409
410         /* create temporary multipart for content */
411         sigmultipart = procmime_mimeinfo_new();
412         sigmultipart->type = MIMETYPE_MULTIPART;
413         sigmultipart->subtype = g_strdup("signed");
414         boundary = generate_mime_boundary("Signature");
415         g_hash_table_insert(sigmultipart->typeparameters, g_strdup("boundary"),
416                             g_strdup(boundary));
417         g_hash_table_insert(sigmultipart->typeparameters, g_strdup("protocol"),
418                             g_strdup("application/pgp-signature"));
419         g_node_append(sigmultipart->node, msgcontent->node);
420         g_node_append(mimeinfo->node, sigmultipart->node);
421
422         /* write message content to temporary file */
423         fp = my_tmpfile();
424         procmime_write_mimeinfo(sigmultipart, fp);
425         rewind(fp);
426
427         /* read temporary file into memory */
428         textstr = get_canonical_content(fp, boundary);
429
430         fclose(fp);
431
432         gpgme_data_new_from_mem(&gpgtext, textstr, strlen(textstr), 0);
433         gpgme_data_new(&gpgsig);
434         gpgme_new(&ctx);
435         gpgme_set_textmode(ctx, 1);
436         gpgme_set_armor(ctx, 1);
437         gpgme_signers_clear (ctx);
438
439         if (!sgpgme_setup_signers(ctx, account)) {
440                 gpgme_release(ctx);
441                 return FALSE;
442         }
443
444         if (!getenv("GPG_AGENT_INFO")) {
445                 info.c = ctx;
446                 gpgme_set_passphrase_cb (ctx, gpgmegtk_passphrase_cb, &info);
447         }
448
449         if (gpgme_op_sign(ctx, gpgtext, gpgsig, GPGME_SIG_MODE_DETACH) != GPG_ERR_NO_ERROR) {
450                 gpgme_release(ctx);
451                 return FALSE;
452         }
453         result = gpgme_op_sign_result(ctx);
454         if (result && result->signatures) {
455             if (gpgme_get_protocol(ctx) == GPGME_PROTOCOL_OpenPGP) {
456                 micalg = g_strdup_printf("PGP-%s", gpgme_hash_algo_name(
457                             result->signatures->hash_algo));
458             } else {
459                 micalg = g_strdup(gpgme_hash_algo_name(
460                             result->signatures->hash_algo));
461             }
462         } else {
463             /* can't get result (maybe no signing key?) */
464             return FALSE;
465         }
466
467         gpgme_release(ctx);
468         sigcontent = gpgme_data_release_and_get_mem(gpgsig, &len);
469         gpgme_data_release(gpgtext);
470         g_free(textstr);
471
472         /* add signature */
473         g_hash_table_insert(sigmultipart->typeparameters, g_strdup("micalg"),
474                             micalg);
475
476         newinfo = procmime_mimeinfo_new();
477         newinfo->type = MIMETYPE_APPLICATION;
478         newinfo->subtype = g_strdup("pgp-signature");
479         newinfo->content = MIMECONTENT_MEM;
480         newinfo->data.mem = g_malloc(len + 1);
481         g_memmove(newinfo->data.mem, sigcontent, len);
482         newinfo->data.mem[len] = '\0';
483         g_node_append(sigmultipart->node, newinfo->node);
484
485         g_free(sigcontent);
486
487         return TRUE;
488 }
489 gchar *pgpmime_get_encrypt_data(GSList *recp_names)
490 {
491         return sgpgme_get_encrypt_data(recp_names);
492 }
493
494 gboolean pgpmime_encrypt(MimeInfo *mimeinfo, const gchar *encrypt_data)
495 {
496         MimeInfo *msgcontent, *encmultipart, *newinfo;
497         FILE *fp;
498         gchar *boundary, *enccontent;
499         size_t len;
500         gchar *textstr;
501         gpgme_data_t gpgtext = NULL, gpgenc = NULL;
502         gpgme_ctx_t ctx = NULL;
503         gpgme_key_t *kset = NULL;
504         gchar **fprs = g_strsplit(encrypt_data, " ", -1);
505         gint i = 0;
506         while (fprs[i] && strlen(fprs[i])) {
507                 i++;
508         }
509         
510         kset = g_malloc(sizeof(gpgme_key_t)*(i+1));
511         memset(kset, 0, sizeof(gpgme_key_t)*(i+1));
512         gpgme_new(&ctx);
513         i = 0;
514         while (fprs[i] && strlen(fprs[i])) {
515                 gpgme_key_t key;
516                 gpgme_error_t err;
517                 err = gpgme_get_key(ctx, fprs[i], &key, 0);
518                 if (err) {
519                         debug_print("can't add key '%s'[%d] (%s)\n", fprs[i],i, gpgme_strerror(err));
520                         break;
521                 }
522                 debug_print("found %s at %d\n", fprs[i], i);
523                 kset[i] = key;
524                 i++;
525         }
526         
527         debug_print("Encrypting message content\n");
528
529         /* remove content node from message */
530         msgcontent = (MimeInfo *) mimeinfo->node->children->data;
531         g_node_unlink(msgcontent->node);
532
533         /* create temporary multipart for content */
534         encmultipart = procmime_mimeinfo_new();
535         encmultipart->type = MIMETYPE_MULTIPART;
536         encmultipart->subtype = g_strdup("encrypted");
537         boundary = generate_mime_boundary("Encrypt");
538         g_hash_table_insert(encmultipart->typeparameters, g_strdup("boundary"),
539                             g_strdup(boundary));
540         g_hash_table_insert(encmultipart->typeparameters, g_strdup("protocol"),
541                             g_strdup("application/pgp-encrypted"));
542         g_node_append(encmultipart->node, msgcontent->node);
543
544         /* write message content to temporary file */
545         fp = my_tmpfile();
546         procmime_write_mimeinfo(encmultipart, fp);
547         rewind(fp);
548
549         /* read temporary file into memory */
550         textstr = get_canonical_content(fp, boundary);
551
552         fclose(fp);
553
554         /* encrypt data */
555         gpgme_data_new_from_mem(&gpgtext, textstr, strlen(textstr), 0);
556         gpgme_data_new(&gpgenc);
557         gpgme_set_armor(ctx, 1);
558         gpgme_data_rewind(gpgtext);
559         
560         gpgme_op_encrypt(ctx, kset, GPGME_ENCRYPT_ALWAYS_TRUST, gpgtext, gpgenc);
561
562         gpgme_release(ctx);
563         enccontent = gpgme_data_release_and_get_mem(gpgenc, &len);
564         gpgme_data_release(gpgtext);
565         g_free(textstr);
566
567         /* create encrypted multipart */
568         g_node_unlink(msgcontent->node);
569         procmime_mimeinfo_free_all(msgcontent);
570         g_node_append(mimeinfo->node, encmultipart->node);
571
572         newinfo = procmime_mimeinfo_new();
573         newinfo->type = MIMETYPE_APPLICATION;
574         newinfo->subtype = g_strdup("pgp-encrypted");
575         newinfo->content = MIMECONTENT_MEM;
576         newinfo->data.mem = g_strdup("Version: 1\n");
577         g_node_append(encmultipart->node, newinfo->node);
578
579         newinfo = procmime_mimeinfo_new();
580         newinfo->type = MIMETYPE_APPLICATION;
581         newinfo->subtype = g_strdup("octet-stream");
582         newinfo->content = MIMECONTENT_MEM;
583         newinfo->data.mem = g_malloc(len + 1);
584         g_memmove(newinfo->data.mem, enccontent, len);
585         newinfo->data.mem[len] = '\0';
586         g_node_append(encmultipart->node, newinfo->node);
587
588         g_free(enccontent);
589
590         return TRUE;
591 }
592
593 static PrivacySystem pgpmime_system = {
594         "pgpmime",                      /* id */
595         "PGP MIME",                     /* name */
596
597         pgpmime_free_privacydata,       /* free_privacydata */
598
599         pgpmime_is_signed,              /* is_signed(MimeInfo *) */
600         pgpmime_check_signature,        /* check_signature(MimeInfo *) */
601         pgpmime_get_sig_status,         /* get_sig_status(MimeInfo *) */
602         pgpmime_get_sig_info_short,     /* get_sig_info_short(MimeInfo *) */
603         pgpmime_get_sig_info_full,      /* get_sig_info_full(MimeInfo *) */
604
605         pgpmime_is_encrypted,           /* is_encrypted(MimeInfo *) */
606         pgpmime_decrypt,                /* decrypt(MimeInfo *) */
607
608         TRUE,
609         pgpmime_sign,
610
611         TRUE,
612         pgpmime_get_encrypt_data,
613         pgpmime_encrypt,
614 };
615
616 void pgpmime_init()
617 {
618         privacy_register_system(&pgpmime_system);
619 }
620
621 void pgpmime_done()
622 {
623         privacy_unregister_system(&pgpmime_system);
624 }
625
626 #endif /* USE_GPGME */