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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 #include "pgpmime.h"
  35 #include "sgpgme.h"
  36 #include "prefs_common.h"
  37 #include "prefs_gpg.h"
  38 #include "passphrase.h"
  39
  40 typedef struct _PrivacyDataPGP PrivacyDataPGP;
  41
  42 struct _PrivacyDataPGP
  43 {
  44         PrivacyData     data;
  45
  46         gboolean        done_sigtest;
  47         gboolean        is_signed;
  48         gpgme_verify_result_t   sigstatus;
  49         gpgme_ctx_t     ctx;
  50 };
  51
  52 static PrivacySystem pgpmime_system;
  53
  54 static gint pgpmime_check_signature(MimeInfo *mimeinfo);
  55
  56 static PrivacyDataPGP *pgpmime_new_privacydata()
  57 {
  58         PrivacyDataPGP *data;
  59
  60         data = g_new0(PrivacyDataPGP, 1);
  61         data->data.system = &pgpmime_system;
  62         data->done_sigtest = FALSE;
  63         data->is_signed = FALSE;
  64         data->sigstatus = NULL;
  65         gpgme_new(&data->ctx);
  66
  67         return data;
  68 }
  69
  70 static void pgpmime_free_privacydata(PrivacyData *_data)
  71 {
  72         PrivacyDataPGP *data = (PrivacyDataPGP *) _data;
  73         gpgme_release(data->ctx);
  74         g_free(data);
  75 }
  76
  77 static gboolean pgpmime_is_signed(MimeInfo *mimeinfo)
  78 {
  79         MimeInfo *parent;
  80         MimeInfo *signature;
  81         const gchar *protocol;
  82         PrivacyDataPGP *data = NULL;
  83
  84         g_return_val_if_fail(mimeinfo != NULL, FALSE);
  85         if (mimeinfo->privacy != NULL) {
  86                 data = (PrivacyDataPGP *) mimeinfo->privacy;
  87                 if (data->done_sigtest)
  88                         return data->is_signed;
  89         }
  90
  91         /* check parent */
  92         parent = procmime_mimeinfo_parent(mimeinfo);
  93         if (parent == NULL)
  94                 return FALSE;
  95         if ((parent->type != MIMETYPE_MULTIPART) ||
  96             g_ascii_strcasecmp(parent->subtype, "signed"))
  97                 return FALSE;
  98         protocol = procmime_mimeinfo_get_parameter(parent, "protocol");
  99         if ((protocol == NULL) || g_ascii_strcasecmp(protocol, "application/pgp-signature"))
 100                 return FALSE;
 101
 102         /* check if mimeinfo is the first child */
 103         if (parent->node->children->data != mimeinfo)
 104                 return FALSE;
 105
 106         /* check signature */
 107         signature = parent->node->children->next != NULL ?
 108             (MimeInfo *) parent->node->children->next->data : NULL;
 109         if (signature == NULL)
 110                 return FALSE;
 111         if ((signature->type != MIMETYPE_APPLICATION) ||
 112             g_ascii_strcasecmp(signature->subtype, "pgp-signature"))
 113                 return FALSE;
 114
 115         if (data == NULL) {
 116                 data = pgpmime_new_privacydata();
 117                 mimeinfo->privacy = (PrivacyData *) data;
 118         }
 119         data->done_sigtest = TRUE;
 120         data->is_signed = TRUE;
 121
 122         return TRUE;
 123 }
 124
 125 static gchar *get_canonical_content(FILE *fp, const gchar *boundary)
 126 {
 127         gchar *ret;
 128         GString *textbuffer;
 129         guint boundary_len;
 130         gchar buf[BUFFSIZE];
 131
 132         boundary_len = strlen(boundary);
 133         while (fgets(buf, sizeof(buf), fp) != NULL)
 134                 if (IS_BOUNDARY(buf, boundary, boundary_len))
 135                         break;
 136
 137         textbuffer = g_string_new("");
 138         while (fgets(buf, sizeof(buf), fp) != NULL) {
 139                 gchar *buf2;
 140
 141                 if (IS_BOUNDARY(buf, boundary, boundary_len))
 142                         break;
 143
 144                 buf2 = canonicalize_str(buf);
 145                 g_string_append(textbuffer, buf2);
 146                 g_free(buf2);
 147         }
 148         g_string_truncate(textbuffer, textbuffer->len - 2);
 149
 150         ret = textbuffer->str;
 151         g_string_free(textbuffer, FALSE);
 152
 153         return ret;
 154 }
 155
 156 static gint pgpmime_check_signature(MimeInfo *mimeinfo)
 157 {
 158         PrivacyDataPGP *data;
 159         MimeInfo *parent, *signature;
 160         FILE *fp;
 161         gchar *boundary;
 162         gchar *textstr;
 163         gpgme_data_t sigdata = NULL, textdata = NULL;
 164         gpgme_error_t err;
 165         g_return_val_if_fail(mimeinfo != NULL, -1);
 166         g_return_val_if_fail(mimeinfo->privacy != NULL, -1);
 167         data = (PrivacyDataPGP *) mimeinfo->privacy;
 168         gpgme_new(&data->ctx);
 169
 170         debug_print("Checking PGP/MIME signature\n");
 171         parent = procmime_mimeinfo_parent(mimeinfo);
 172
 173         fp = fopen(parent->data.filename, "rb");
 174         g_return_val_if_fail(fp != NULL, SIGNATURE_INVALID);
 175
 176         boundary = g_hash_table_lookup(parent->typeparameters, "boundary");
 177         if (!boundary)
 178                 return 0;
 179
 180         textstr = get_canonical_content(fp, boundary);
 181
 182         err = gpgme_data_new_from_mem(&textdata, textstr, strlen(textstr), 0);
 183         if (err) {
 184                 debug_print ("gpgme_data_new_from_mem failed: %s\n",
 185                    gpgme_strerror (err));
 186         }
 187         signature = (MimeInfo *) mimeinfo->node->next->data;
 188         sigdata = sgpgme_data_from_mimeinfo(signature);
 189
 190         data->sigstatus =
 191                 sgpgme_verify_signature (data->ctx, sigdata, textdata, NULL);
 192
 193         gpgme_data_release(sigdata);
 194         gpgme_data_release(textdata);
 195         g_free(textstr);
 196         fclose(fp);
 197
 198         return 0;
 199 }
 200
 201 static SignatureStatus pgpmime_get_sig_status(MimeInfo *mimeinfo)
 202 {
 203         PrivacyDataPGP *data = (PrivacyDataPGP *) mimeinfo->privacy;
 204
 205         g_return_val_if_fail(data != NULL, SIGNATURE_INVALID);
 206
 207         if (data->sigstatus == NULL &&
 208             prefs_gpg_get_config()->auto_check_signatures)
 209                 pgpmime_check_signature(mimeinfo);
 210
 211         return sgpgme_sigstat_gpgme_to_privacy(data->ctx, data->sigstatus);
 212 }
 213
 214 static gchar *pgpmime_get_sig_info_short(MimeInfo *mimeinfo)
 215 {
 216         PrivacyDataPGP *data = (PrivacyDataPGP *) mimeinfo->privacy;
 217
 218         g_return_val_if_fail(data != NULL, g_strdup("Error"));
 219
 220         if (data->sigstatus == NULL &&
 221             prefs_gpg_get_config()->auto_check_signatures)
 222                 pgpmime_check_signature(mimeinfo);
 223
 224         return sgpgme_sigstat_info_short(data->ctx, data->sigstatus);
 225 }
 226
 227 static gchar *pgpmime_get_sig_info_full(MimeInfo *mimeinfo)
 228 {
 229         PrivacyDataPGP *data = (PrivacyDataPGP *) mimeinfo->privacy;
 230
 231         g_return_val_if_fail(data != NULL, g_strdup("Error"));
 232
 233         if (data->sigstatus == NULL &&
 234             prefs_gpg_get_config()->auto_check_signatures)
 235                 pgpmime_check_signature(mimeinfo);
 236
 237         return sgpgme_sigstat_info_full(data->ctx, data->sigstatus);
 238 }
 239
 240 static gboolean pgpmime_is_encrypted(MimeInfo *mimeinfo)
 241 {
 242         MimeInfo *tmpinfo;
 243         const gchar *tmpstr;
 244
 245         if (mimeinfo->type != MIMETYPE_MULTIPART)
 246                 return FALSE;
 247         if (g_ascii_strcasecmp(mimeinfo->subtype, "encrypted"))
 248                 return FALSE;
 249         tmpstr = procmime_mimeinfo_get_parameter(mimeinfo, "protocol");
 250         if ((tmpstr == NULL) || g_ascii_strcasecmp(tmpstr, "application/pgp-encrypted"))
 251                 return FALSE;
 252         if (g_node_n_children(mimeinfo->node) != 2)
 253                 return FALSE;
 254
 255         tmpinfo = (MimeInfo *) g_node_nth_child(mimeinfo->node, 0)->data;
 256         if (tmpinfo->type != MIMETYPE_APPLICATION)
 257                 return FALSE;
 258         if (g_ascii_strcasecmp(tmpinfo->subtype, "pgp-encrypted"))
 259                 return FALSE;
 260
 261         tmpinfo = (MimeInfo *) g_node_nth_child(mimeinfo->node, 1)->data;
 262         if (tmpinfo->type != MIMETYPE_APPLICATION)
 263                 return FALSE;
 264         if (g_ascii_strcasecmp(tmpinfo->subtype, "octet-stream"))
 265                 return FALSE;
 266
 267         return TRUE;
 268 }
 269
 270 static MimeInfo *pgpmime_decrypt(MimeInfo *mimeinfo)
 271 {
 272         MimeInfo *encinfo, *decinfo, *parseinfo;
 273         gpgme_data_t cipher = NULL, plain = NULL;
 274         static gint id = 0;
 275         FILE *dstfp;
 276         gint nread;
 277         gchar *fname;
 278         gchar buf[BUFFSIZE];
 279         gpgme_verify_result_t sigstat = NULL;
 280         PrivacyDataPGP *data = NULL;
 281         gpgme_ctx_t ctx;
 282
 283         if (gpgme_new(&ctx) != GPG_ERR_NO_ERROR)
 284                 return NULL;
 285
 286
 287         g_return_val_if_fail(pgpmime_is_encrypted(mimeinfo), NULL);
 288
 289         encinfo = (MimeInfo *) g_node_nth_child(mimeinfo->node, 1)->data;
 290
 291         cipher = sgpgme_data_from_mimeinfo(encinfo);
 292         plain = sgpgme_decrypt_verify(cipher, &sigstat, ctx);
 293
 294         gpgme_data_release(cipher);
 295         if (plain == NULL) {
 296                 debug_print("plain is null!\n");
 297                 gpgme_release(ctx);
 298                 return NULL;
 299         }
 300
 301         fname = g_strdup_printf("%s%cplaintext.%08x",
 302                 get_mime_tmp_dir(), G_DIR_SEPARATOR, ++id);
 303
 304         if ((dstfp = fopen(fname, "wb")) == NULL) {
 305                 FILE_OP_ERROR(fname, "fopen");
 306                 g_free(fname);
 307                 gpgme_data_release(plain);
 308                 gpgme_release(ctx);
 309                 debug_print("can't open!\n");
 310                 return NULL;
 311         }
 312
 313         fprintf(dstfp, "MIME-Version: 1.0\n");
 314
 315         while ((nread = gpgme_data_read(plain, buf, sizeof(buf))) > 0) {
 316                 debug_print("read %d:%s\n", nread, buf);
 317                 fwrite (buf, nread, 1, dstfp);
 318         }
 319         debug_print("nread %d!\n", nread);
 320         fclose(dstfp);
 321
 322         gpgme_data_release(plain);
 323
 324         parseinfo = procmime_scan_file(fname);
 325         g_free(fname);
 326         if (parseinfo == NULL) {
 327                 gpgme_release(ctx);
 328                 return NULL;
 329         }
 330         decinfo = g_node_first_child(parseinfo->node) != NULL ?
 331                 g_node_first_child(parseinfo->node)->data : NULL;
 332         if (decinfo == NULL) {
 333                 gpgme_release(ctx);
 334                 return NULL;
 335         }
 336
 337         g_node_unlink(decinfo->node);
 338         procmime_mimeinfo_free_all(parseinfo);
 339
 340         decinfo->tmp = TRUE;
 341
 342         if (sigstat != NULL && sigstat->signatures != NULL) {
 343                 if (decinfo->privacy != NULL) {
 344                         data = (PrivacyDataPGP *) decinfo->privacy;
 345                 } else {
 346                         data = pgpmime_new_privacydata();
 347                         decinfo->privacy = (PrivacyData *) data;
 348                 }
 349                 data->done_sigtest = TRUE;
 350                 data->is_signed = TRUE;
 351                 data->sigstatus = sigstat;
 352                 if (data->ctx)
 353                         gpgme_release(data->ctx);
 354                 data->ctx = ctx;
 355         } else
 356                 gpgme_release(ctx);
 357
 358         return decinfo;
 359 }
 360
 361 gboolean pgpmime_sign(MimeInfo *mimeinfo, PrefsAccount *account)
 362 {
 363         MimeInfo *msgcontent, *sigmultipart, *newinfo;
 364         gchar *textstr, *micalg;
 365         FILE *fp;
 366         gchar *boundary, *sigcontent;
 367         gpgme_ctx_t ctx;
 368         gpgme_data_t gpgtext, gpgsig;
 369         size_t len;
 370         struct passphrase_cb_info_s info;
 371         gpgme_sign_result_t result = NULL;
 372
 373         memset (&info, 0, sizeof info);
 374
 375         /* remove content node from message */
 376         msgcontent = (MimeInfo *) mimeinfo->node->children->data;
 377         g_node_unlink(msgcontent->node);
 378
 379         /* create temporary multipart for content */
 380         sigmultipart = procmime_mimeinfo_new();
 381         sigmultipart->type = MIMETYPE_MULTIPART;
 382         sigmultipart->subtype = g_strdup("signed");
 383         boundary = generate_mime_boundary("Signature");
 384         g_hash_table_insert(sigmultipart->typeparameters, g_strdup("boundary"),
 385                             g_strdup(boundary));
 386         g_hash_table_insert(sigmultipart->typeparameters, g_strdup("protocol"),
 387                             g_strdup("application/pgp-signature"));
 388         g_node_append(sigmultipart->node, msgcontent->node);
 389         g_node_append(mimeinfo->node, sigmultipart->node);
 390
 391         /* write message content to temporary file */
 392         fp = my_tmpfile();
 393         procmime_write_mimeinfo(sigmultipart, fp);
 394         rewind(fp);
 395
 396         /* read temporary file into memory */
 397         textstr = get_canonical_content(fp, boundary);
 398
 399         fclose(fp);
 400
 401         gpgme_data_new_from_mem(&gpgtext, textstr, strlen(textstr), 0);
 402         gpgme_data_new(&gpgsig);
 403         gpgme_new(&ctx);
 404         gpgme_set_textmode(ctx, 1);
 405         gpgme_set_armor(ctx, 1);
 406         gpgme_signers_clear (ctx);
 407
 408         if (!sgpgme_setup_signers(ctx, account)) {
 409                 gpgme_release(ctx);
 410                 return FALSE;
 411         }
 412
 413         if (!getenv("GPG_AGENT_INFO")) {
 414                 info.c = ctx;
 415                 gpgme_set_passphrase_cb (ctx, gpgmegtk_passphrase_cb, &info);
 416         }
 417
 418         if (gpgme_op_sign(ctx, gpgtext, gpgsig, GPGME_SIG_MODE_DETACH) != GPG_ERR_NO_ERROR) {
 419                 gpgme_release(ctx);
 420                 return FALSE;
 421         }
 422         result = gpgme_op_sign_result(ctx);
 423         if (result && result->signatures) {
 424             if (gpgme_get_protocol(ctx) == GPGME_PROTOCOL_OpenPGP) {
 425                 micalg = g_strdup_printf("PGP-%s", gpgme_hash_algo_name(
 426                             result->signatures->hash_algo));
 427             } else {
 428                 micalg = g_strdup(gpgme_hash_algo_name(
 429                             result->signatures->hash_algo));
 430             }
 431         } else {
 432             /* can't get result (maybe no signing key?) */
 433             return FALSE;
 434         }
 435
 436         gpgme_release(ctx);
 437         sigcontent = gpgme_data_release_and_get_mem(gpgsig, &len);
 438         gpgme_data_release(gpgtext);
 439         g_free(textstr);
 440
 441         /* add signature */
 442         g_hash_table_insert(sigmultipart->typeparameters, g_strdup("micalg"),
 443                             micalg);
 444
 445         newinfo = procmime_mimeinfo_new();
 446         newinfo->type = MIMETYPE_APPLICATION;
 447         newinfo->subtype = g_strdup("pgp-signature");
 448         newinfo->content = MIMECONTENT_MEM;
 449         newinfo->data.mem = g_malloc(len + 1);
 450         g_memmove(newinfo->data.mem, sigcontent, len);
 451         newinfo->data.mem[len] = '\0';
 452         g_node_append(sigmultipart->node, newinfo->node);
 453
 454         g_free(sigcontent);
 455
 456         return TRUE;
 457 }
 458 gchar *pgpmime_get_encrypt_data(GSList *recp_names)
 459 {
 460         return sgpgme_get_encrypt_data(recp_names);
 461 }
 462
 463 gboolean pgpmime_encrypt(MimeInfo *mimeinfo, const gchar *encrypt_data)
 464 {
 465         MimeInfo *msgcontent, *encmultipart, *newinfo;
 466         FILE *fp;
 467         gchar *boundary, *enccontent;
 468         size_t len;
 469         gchar *textstr;
 470         gpgme_data_t gpgtext = NULL, gpgenc = NULL;
 471         gpgme_ctx_t ctx = NULL;
 472         gpgme_key_t *kset = NULL;
 473         gchar **fprs = g_strsplit(encrypt_data, " ", -1);
 474         gint i = 0;
 475         while (fprs[i] && strlen(fprs[i])) {
 476                 i++;
 477         }
 478
 479         kset = g_malloc(sizeof(gpgme_key_t)*(i+1));
 480         memset(kset, 0, sizeof(gpgme_key_t)*(i+1));
 481         gpgme_new(&ctx);
 482         i = 0;
 483         while (fprs[i] && strlen(fprs[i])) {
 484                 gpgme_key_t key;
 485                 gpgme_error_t err;
 486                 err = gpgme_get_key(ctx, fprs[i], &key, 0);
 487                 if (err) {
 488                         debug_print("can't add key '%s'[%d] (%s)\n", fprs[i],i, gpgme_strerror(err));
 489                         break;
 490                 }
 491                 debug_print("found %s at %d\n", fprs[i], i);
 492                 kset[i] = key;
 493                 i++;
 494         }
 495
 496         debug_print("Encrypting message content\n");
 497
 498         /* remove content node from message */
 499         msgcontent = (MimeInfo *) mimeinfo->node->children->data;
 500         g_node_unlink(msgcontent->node);
 501
 502         /* create temporary multipart for content */
 503         encmultipart = procmime_mimeinfo_new();
 504         encmultipart->type = MIMETYPE_MULTIPART;
 505         encmultipart->subtype = g_strdup("encrypted");
 506         boundary = generate_mime_boundary("Encrypt");
 507         g_hash_table_insert(encmultipart->typeparameters, g_strdup("boundary"),
 508                             g_strdup(boundary));
 509         g_hash_table_insert(encmultipart->typeparameters, g_strdup("protocol"),
 510                             g_strdup("application/pgp-encrypted"));
 511         g_node_append(encmultipart->node, msgcontent->node);
 512
 513         /* write message content to temporary file */
 514         fp = my_tmpfile();
 515         procmime_write_mimeinfo(encmultipart, fp);
 516         rewind(fp);
 517
 518         /* read temporary file into memory */
 519         textstr = get_canonical_content(fp, boundary);
 520
 521         fclose(fp);
 522
 523         /* encrypt data */
 524         gpgme_data_new_from_mem(&gpgtext, textstr, strlen(textstr), 0);
 525         gpgme_data_new(&gpgenc);
 526         gpgme_set_armor(ctx, 1);
 527         gpgme_data_seek(gpgtext, 0, SEEK_SET);
 528
 529         gpgme_op_encrypt(ctx, kset, GPGME_ENCRYPT_ALWAYS_TRUST, gpgtext, gpgenc);
 530
 531         gpgme_release(ctx);
 532         enccontent = gpgme_data_release_and_get_mem(gpgenc, &len);
 533         gpgme_data_release(gpgtext);
 534         g_free(textstr);
 535
 536         /* create encrypted multipart */
 537         g_node_unlink(msgcontent->node);
 538         procmime_mimeinfo_free_all(msgcontent);
 539         g_node_append(mimeinfo->node, encmultipart->node);
 540
 541         newinfo = procmime_mimeinfo_new();
 542         newinfo->type = MIMETYPE_APPLICATION;
 543         newinfo->subtype = g_strdup("pgp-encrypted");
 544         newinfo->content = MIMECONTENT_MEM;
 545         newinfo->data.mem = g_strdup("Version: 1\n");
 546         g_node_append(encmultipart->node, newinfo->node);
 547
 548         newinfo = procmime_mimeinfo_new();
 549         newinfo->type = MIMETYPE_APPLICATION;
 550         newinfo->subtype = g_strdup("octet-stream");
 551         newinfo->content = MIMECONTENT_MEM;
 552         newinfo->data.mem = g_malloc(len + 1);
 553         g_memmove(newinfo->data.mem, enccontent, len);
 554         newinfo->data.mem[len] = '\0';
 555         g_node_append(encmultipart->node, newinfo->node);
 556
 557         g_free(enccontent);
 558
 559         return TRUE;
 560 }
 561
 562 static PrivacySystem pgpmime_system = {
 563         "pgpmime",                      /* id */
 564         "PGP MIME",                     /* name */
 565
 566         pgpmime_free_privacydata,       /* free_privacydata */
 567
 568         pgpmime_is_signed,              /* is_signed(MimeInfo *) */
 569         pgpmime_check_signature,        /* check_signature(MimeInfo *) */
 570         pgpmime_get_sig_status,         /* get_sig_status(MimeInfo *) */
 571         pgpmime_get_sig_info_short,     /* get_sig_info_short(MimeInfo *) */
 572         pgpmime_get_sig_info_full,      /* get_sig_info_full(MimeInfo *) */
 573
 574         pgpmime_is_encrypted,           /* is_encrypted(MimeInfo *) */
 575         pgpmime_decrypt,                /* decrypt(MimeInfo *) */
 576
 577         TRUE,
 578         pgpmime_sign,
 579
 580         TRUE,
 581         pgpmime_get_encrypt_data,
 582         pgpmime_encrypt,
 583 };
 584
 585 void pgpmime_init()
 586 {
 587         privacy_register_system(&pgpmime_system);
 588 }
 589
 590 void pgpmime_done()
 591 {
 592         privacy_unregister_system(&pgpmime_system);
 593 }
 594
 595 #endif /* USE_GPGME */