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