summaryrefslogtreecommitdiff
path: root/src/engine-uiserver.c
blob: 87ae16254979aad4b6c257966c097c3546a5b16c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
/* engine-uiserver.c - Uiserver engine.
   Copyright (C) 2000 Werner Koch (dd9jn)
   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2009 g10 Code GmbH
 
   This file is part of GPGME.

   GPGME is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of
   the License, or (at your option) any later version.
   
   GPGME is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.
   
   You should have received a copy of the GNU Lesser General Public
   License along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA.  */

/* Peculiar: Use special keys from email address for recipient and
   signer (==sender).  Use no data objects with encryption for
   prep_encrypt.  */

#if HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <string.h>
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#include <assert.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <locale.h>
#include <fcntl.h> /* FIXME */
#include <errno.h>

#include "gpgme.h"
#include "util.h"
#include "ops.h"
#include "wait.h"
#include "priv-io.h"
#include "sema.h"
#include "data.h"

#include "assuan.h"
#include "status-table.h"
#include "debug.h"

#include "engine-backend.h"


typedef struct
{
  int fd;	/* FD we talk about.  */
  int server_fd;/* Server FD for this connection.  */
  int dir;	/* Inbound/Outbound, maybe given implicit?  */
  void *data;	/* Handler-specific data.  */
  void *tag;	/* ID from the user for gpgme_remove_io_callback.  */
  char server_fd_str[15]; /* Same as SERVER_FD but as a string.  We
                             need this because _gpgme_io_fd2str can't
                             be used on a closed descriptor.  */
} iocb_data_t;


struct engine_uiserver
{
  assuan_context_t assuan_ctx;

  int lc_ctype_set;
  int lc_messages_set;
  gpgme_protocol_t protocol;

  iocb_data_t status_cb;

  /* Input, output etc are from the servers perspective.  */
  iocb_data_t input_cb;
  gpgme_data_t input_helper_data;  /* Input helper data object.  */
  void *input_helper_memory;       /* Input helper memory block.  */

  iocb_data_t output_cb;

  iocb_data_t message_cb;

  struct
  {
    engine_status_handler_t fnc;
    void *fnc_value;
  } status;

  struct
  {
    engine_colon_line_handler_t fnc;
    void *fnc_value;
    struct
    {
      char *line;
      int linesize;
      int linelen;
    } attic;
    int any; /* any data line seen */
  } colon; 

  gpgme_data_t inline_data;  /* Used to collect D lines.  */

  struct gpgme_io_cbs io_cbs;
};

typedef struct engine_uiserver *engine_uiserver_t;


static void uiserver_io_event (void *engine, 
                            gpgme_event_io_t type, void *type_data);



static char *
uiserver_get_version (const char *file_name)
{
  return strdup ("1.0");
}


static const char *
uiserver_get_req_version (void)
{
  return "1.0";
}


static void
close_notify_handler (int fd, void *opaque)
{
  engine_uiserver_t uiserver = opaque;

  assert (fd != -1);
  if (uiserver->status_cb.fd == fd)
    {
      if (uiserver->status_cb.tag)
	(*uiserver->io_cbs.remove) (uiserver->status_cb.tag);
      uiserver->status_cb.fd = -1;
      uiserver->status_cb.tag = NULL;
    }
  else if (uiserver->input_cb.fd == fd)
    {
      if (uiserver->input_cb.tag)
	(*uiserver->io_cbs.remove) (uiserver->input_cb.tag);
      uiserver->input_cb.fd = -1;
      uiserver->input_cb.tag = NULL;
      if (uiserver->input_helper_data)
        {
          gpgme_data_release (uiserver->input_helper_data);
          uiserver->input_helper_data = NULL;
        }
      if (uiserver->input_helper_memory)
        {
          free (uiserver->input_helper_memory);
          uiserver->input_helper_memory = NULL;
        }
    }
  else if (uiserver->output_cb.fd == fd)
    {
      if (uiserver->output_cb.tag)
	(*uiserver->io_cbs.remove) (uiserver->output_cb.tag);
      uiserver->output_cb.fd = -1;
      uiserver->output_cb.tag = NULL;
    }
  else if (uiserver->message_cb.fd == fd)
    {
      if (uiserver->message_cb.tag)
	(*uiserver->io_cbs.remove) (uiserver->message_cb.tag);
      uiserver->message_cb.fd = -1;
      uiserver->message_cb.tag = NULL;
    }
}


/* This is the default inquiry callback.  We use it to handle the
   Pinentry notifications.  */
static gpgme_error_t
default_inq_cb (engine_uiserver_t uiserver, const char *line)
{
  if (!strncmp (line, "PINENTRY_LAUNCHED", 17) && (line[17]==' '||!line[17]))
    {
      _gpgme_allow_set_foreground_window ((pid_t)strtoul (line+17, NULL, 10));
    }

  return 0;
}


static gpgme_error_t
uiserver_cancel (void *engine)
{
  engine_uiserver_t uiserver = engine;

  if (!uiserver)
    return gpg_error (GPG_ERR_INV_VALUE);

  if (uiserver->status_cb.fd != -1)
    _gpgme_io_close (uiserver->status_cb.fd);
  if (uiserver->input_cb.fd != -1)
    _gpgme_io_close (uiserver->input_cb.fd);
  if (uiserver->output_cb.fd != -1)
    _gpgme_io_close (uiserver->output_cb.fd);
  if (uiserver->message_cb.fd != -1)
    _gpgme_io_close (uiserver->message_cb.fd);

  if (uiserver->assuan_ctx)
    {
      assuan_release (uiserver->assuan_ctx);
      uiserver->assuan_ctx = NULL;
    }

  return 0;
}


static void
uiserver_release (void *engine)
{
  engine_uiserver_t uiserver = engine;

  if (!uiserver)
    return;

  uiserver_cancel (engine);

  free (uiserver->colon.attic.line);
  free (uiserver);
}


static gpgme_error_t
uiserver_new (void **engine, const char *file_name, const char *home_dir)
{
  gpgme_error_t err = 0;
  engine_uiserver_t uiserver;
  char *dft_display = NULL;
  char dft_ttyname[64];
  char *dft_ttytype = NULL;
  char *optstr;

  uiserver = calloc (1, sizeof *uiserver);
  if (!uiserver)
    return gpg_error_from_syserror ();

  uiserver->protocol = GPGME_PROTOCOL_DEFAULT;
  uiserver->status_cb.fd = -1;
  uiserver->status_cb.dir = 1;
  uiserver->status_cb.tag = 0;
  uiserver->status_cb.data = uiserver;

  uiserver->input_cb.fd = -1;
  uiserver->input_cb.dir = 0;
  uiserver->input_cb.tag = 0;
  uiserver->input_cb.server_fd = -1;
  *uiserver->input_cb.server_fd_str = 0;
  uiserver->output_cb.fd = -1;
  uiserver->output_cb.dir = 1;
  uiserver->output_cb.tag = 0;
  uiserver->output_cb.server_fd = -1;
  *uiserver->output_cb.server_fd_str = 0;
  uiserver->message_cb.fd = -1;
  uiserver->message_cb.dir = 0;
  uiserver->message_cb.tag = 0;
  uiserver->message_cb.server_fd = -1;
  *uiserver->message_cb.server_fd_str = 0;

  uiserver->status.fnc = 0;
  uiserver->colon.fnc = 0;
  uiserver->colon.attic.line = 0;
  uiserver->colon.attic.linesize = 0;
  uiserver->colon.attic.linelen = 0;
  uiserver->colon.any = 0;

  uiserver->inline_data = NULL;

  uiserver->io_cbs.add = NULL;
  uiserver->io_cbs.add_priv = NULL;
  uiserver->io_cbs.remove = NULL;
  uiserver->io_cbs.event = NULL;
  uiserver->io_cbs.event_priv = NULL;

  err = assuan_new_ext (&uiserver->assuan_ctx, GPG_ERR_SOURCE_GPGME,
			&_gpgme_assuan_malloc_hooks, _gpgme_assuan_log_cb,
			NULL);
  if (err)
    goto leave;
  assuan_ctx_set_system_hooks (uiserver->assuan_ctx,
			       &_gpgme_assuan_system_hooks);

  err = assuan_socket_connect (uiserver->assuan_ctx,
			       file_name ?
			       file_name : _gpgme_get_uiserver_socket_path (),
			       0, ASSUAN_SOCKET_SERVER_FDPASSING);
  if (err)
    goto leave;

  err = _gpgme_getenv ("DISPLAY", &dft_display);
  if (err)
    goto leave;
  if (dft_display)
    {
      if (asprintf (&optstr, "OPTION display=%s", dft_display) < 0)
        {
	  free (dft_display);
	  err = gpg_error_from_errno (errno);
	  goto leave;
	}
      free (dft_display);

      err = assuan_transact (uiserver->assuan_ctx, optstr, NULL, NULL, NULL,
			     NULL, NULL, NULL);
      free (optstr);
      if (err)
	goto leave;
    }

  if (isatty (1))
    {
      int rc;

      rc = ttyname_r (1, dft_ttyname, sizeof (dft_ttyname));
      if (rc)
	{
	  err = gpg_error_from_errno (rc);
	  goto leave;
	}
      else
	{
	  if (asprintf (&optstr, "OPTION ttyname=%s", dft_ttyname) < 0)
	    {
	      err = gpg_error_from_errno (errno);
	      goto leave;
	    }
	  err = assuan_transact (uiserver->assuan_ctx, optstr, NULL, NULL, NULL,
				 NULL, NULL, NULL);
	  free (optstr);
	  if (err)
	    goto leave;

	  err = _gpgme_getenv ("TERM", &dft_ttytype);
	  if (err)
	    goto leave;
	  if (dft_ttytype)
	    {
	      if (asprintf (&optstr, "OPTION ttytype=%s", dft_ttytype) < 0)
		{
		  free (dft_ttytype);
		  err = gpg_error_from_errno (errno);
		  goto leave;
		}
	      free (dft_ttytype);

	      err = assuan_transact (uiserver->assuan_ctx, optstr, NULL, NULL,
				     NULL, NULL, NULL, NULL);
	      free (optstr);
	      if (err)
		goto leave;
	    }
	}
    }

#ifdef HAVE_W32_SYSTEM
  /* Under Windows we need to use AllowSetForegroundWindow.  Tell
     uiserver to tell us when it needs it.  */
  if (!err)
    {
      err = assuan_transact (uiserver->assuan_ctx, "OPTION allow-pinentry-notify",
                             NULL, NULL, NULL, NULL, NULL, NULL);
      if (gpg_err_code (err) == GPG_ERR_UNKNOWN_OPTION)
        err = 0; /* This is a new feature of uiserver.  */
    }
#endif /*HAVE_W32_SYSTEM*/

 leave:
  if (err)
    uiserver_release (uiserver);
  else
    *engine = uiserver;

  return err;
}


static gpgme_error_t
uiserver_set_locale (void *engine, int category, const char *value)
{
  engine_uiserver_t uiserver = engine;
  gpgme_error_t err;
  char *optstr;
  char *catstr;

  /* FIXME: If value is NULL, we need to reset the option to default.
     But we can't do this.  So we error out here.  UISERVER needs support
     for this.  */
  if (category == LC_CTYPE)
    {
      catstr = "lc-ctype";
      if (!value && uiserver->lc_ctype_set)
	return gpg_error (GPG_ERR_INV_VALUE);
      if (value)
	uiserver->lc_ctype_set = 1;
    }
#ifdef LC_MESSAGES
  else if (category == LC_MESSAGES)
    {
      catstr = "lc-messages";
      if (!value && uiserver->lc_messages_set)
	return gpg_error (GPG_ERR_INV_VALUE);
      if (value)
	uiserver->lc_messages_set = 1;
    }
#endif /* LC_MESSAGES */
  else
    return gpg_error (GPG_ERR_INV_VALUE);

  /* FIXME: Reset value to default.  */
  if (!value) 
    return 0;

  if (asprintf (&optstr, "OPTION %s=%s", catstr, value) < 0)
    err = gpg_error_from_errno (errno);
  else
    {
      err = assuan_transact (uiserver->assuan_ctx, optstr, NULL, NULL,
			     NULL, NULL, NULL, NULL);
      free (optstr);
    }

  return err;
}


static gpgme_error_t
uiserver_set_protocol (void *engine, gpgme_protocol_t protocol)
{
  engine_uiserver_t uiserver = engine;

  if (protocol != GPGME_PROTOCOL_OpenPGP
      && protocol != GPGME_PROTOCOL_CMS
      && protocol != GPGME_PROTOCOL_DEFAULT)
    return gpg_error (GPG_ERR_INV_VALUE);

  uiserver->protocol = protocol;
  return 0;
}


static gpgme_error_t
uiserver_assuan_simple_command (assuan_context_t ctx, char *cmd,
			     engine_status_handler_t status_fnc,
			     void *status_fnc_value)
{
  gpg_error_t err;
  char *line;
  size_t linelen;

  err = assuan_write_line (ctx, cmd);
  if (err)
    return err;

  do
    {
      err = assuan_read_line (ctx, &line, &linelen);
      if (err)
	return err;

      if (*line == '#' || !linelen)
	continue;

      if (linelen >= 2
	  && line[0] == 'O' && line[1] == 'K'
	  && (line[2] == '\0' || line[2] == ' '))
	return 0;
      else if (linelen >= 4
	  && line[0] == 'E' && line[1] == 'R' && line[2] == 'R'
	  && line[3] == ' ')
	err = atoi (&line[4]);
      else if (linelen >= 2
	       && line[0] == 'S' && line[1] == ' ')
	{
	  char *rest;
	  gpgme_status_code_t r;

	  rest = strchr (line + 2, ' ');
	  if (!rest)
	    rest = line + linelen; /* set to an empty string */
	  else
	    *(rest++) = 0;

	  r = _gpgme_parse_status (line + 2);

	  if (r >= 0 && status_fnc)
	    err = status_fnc (status_fnc_value, r, rest);
	  else
	    err = gpg_error (GPG_ERR_GENERAL);
	}
      else
	err = gpg_error (GPG_ERR_GENERAL);
    }
  while (!err);

  return err;
}


typedef enum { INPUT_FD, OUTPUT_FD, MESSAGE_FD } fd_type_t;

#define COMMANDLINELEN 40
static gpgme_error_t
uiserver_set_fd (engine_uiserver_t uiserver, fd_type_t fd_type, const char *opt)
{
  gpg_error_t err = 0;
  char line[COMMANDLINELEN];
  char *which;
  iocb_data_t *iocb_data;
  int dir;

  switch (fd_type)
    {
    case INPUT_FD:
      which = "INPUT";
      iocb_data = &uiserver->input_cb;
      break;

    case OUTPUT_FD:
      which = "OUTPUT";
      iocb_data = &uiserver->output_cb;
      break;

    case MESSAGE_FD:
      which = "MESSAGE";
      iocb_data = &uiserver->message_cb;
      break;

    default:
      return gpg_error (GPG_ERR_INV_VALUE);
    }

  dir = iocb_data->dir;

  /* We try to short-cut the communication by giving UISERVER direct
     access to the file descriptor, rather than using a pipe.  */
  iocb_data->server_fd = _gpgme_data_get_fd (iocb_data->data);
  if (iocb_data->server_fd < 0)
    {
      int fds[2];

      if (_gpgme_io_pipe (fds, 0) < 0)
	return gpg_error_from_errno (errno);

      iocb_data->fd = dir ? fds[0] : fds[1];
      iocb_data->server_fd = dir ? fds[1] : fds[0];

      if (_gpgme_io_set_close_notify (iocb_data->fd,
				      close_notify_handler, uiserver))
	{
	  err = gpg_error (GPG_ERR_GENERAL);
	  goto leave_set_fd;
	}
    }

  err = assuan_sendfd (uiserver->assuan_ctx, iocb_data->server_fd);
  if (err)
    goto leave_set_fd;

  _gpgme_io_close (iocb_data->server_fd);
  iocb_data->server_fd = -1;

  if (opt)
    snprintf (line, COMMANDLINELEN, "%s FD %s", which, opt);
  else
    snprintf (line, COMMANDLINELEN, "%s FD", which);

  err = uiserver_assuan_simple_command (uiserver->assuan_ctx, line, NULL, NULL);

 leave_set_fd:
  if (err)
    {
      _gpgme_io_close (iocb_data->fd);
      iocb_data->fd = -1;
      if (iocb_data->server_fd != -1)
        {
          _gpgme_io_close (iocb_data->server_fd);
          iocb_data->server_fd = -1;
        }
    }

  return err;
}


static const char *
map_data_enc (gpgme_data_t d)
{
  switch (gpgme_data_get_encoding (d))
    {
    case GPGME_DATA_ENCODING_NONE:
      break;
    case GPGME_DATA_ENCODING_BINARY:
      return "--binary";
    case GPGME_DATA_ENCODING_BASE64:
      return "--base64";
    case GPGME_DATA_ENCODING_ARMOR:
      return "--armor";
    default:
      break;
    }
  return NULL;
}


static gpgme_error_t
status_handler (void *opaque, int fd)
{
  struct io_cb_data *data = (struct io_cb_data *) opaque;
  engine_uiserver_t uiserver = (engine_uiserver_t) data->handler_value;
  gpgme_error_t err = 0;
  char *line;
  size_t linelen;

  do
    {
      err = assuan_read_line (uiserver->assuan_ctx, &line, &linelen);
      if (err)
	{
	  /* Try our best to terminate the connection friendly.  */
	  /*	  assuan_write_line (uiserver->assuan_ctx, "BYE"); */
          TRACE3 (DEBUG_CTX, "gpgme:status_handler", uiserver,
		  "fd 0x%x: error from assuan (%d) getting status line : %s",
                  fd, err, gpg_strerror (err));
	}
      else if (linelen >= 3
	       && line[0] == 'E' && line[1] == 'R' && line[2] == 'R'
	       && (line[3] == '\0' || line[3] == ' '))
	{
	  if (line[3] == ' ')
	    err = atoi (&line[4]);
	  if (! err)
	    err = gpg_error (GPG_ERR_GENERAL);
          TRACE2 (DEBUG_CTX, "gpgme:status_handler", uiserver,
		  "fd 0x%x: ERR line - mapped to: %s",
                  fd, err ? gpg_strerror (err) : "ok");
	  /* Try our best to terminate the connection friendly.  */
	  /*	  assuan_write_line (uiserver->assuan_ctx, "BYE"); */
	}
      else if (linelen >= 2
	       && line[0] == 'O' && line[1] == 'K'
	       && (line[2] == '\0' || line[2] == ' '))
	{
	  if (uiserver->status.fnc)
	    err = uiserver->status.fnc (uiserver->status.fnc_value,
				     GPGME_STATUS_EOF, "");
	  
	  if (!err && uiserver->colon.fnc && uiserver->colon.any)
            {
              /* We must tell a colon function about the EOF. We do
                 this only when we have seen any data lines.  Note
                 that this inlined use of colon data lines will
                 eventually be changed into using a regular data
                 channel. */
              uiserver->colon.any = 0;
              err = uiserver->colon.fnc (uiserver->colon.fnc_value, NULL);
            }
          TRACE2 (DEBUG_CTX, "gpgme:status_handler", uiserver,
		  "fd 0x%x: OK line - final status: %s",
                  fd, err ? gpg_strerror (err) : "ok");
	  _gpgme_io_close (uiserver->status_cb.fd);
	  return err;
	}
      else if (linelen > 2
	       && line[0] == 'D' && line[1] == ' '
	       && uiserver->colon.fnc)
        {
	  /* We are using the colon handler even for plain inline data
             - strange name for that function but for historic reasons
             we keep it.  */
          /* FIXME We can't use this for binary data because we
             assume this is a string.  For the current usage of colon
             output it is correct.  */
          char *src = line + 2;
	  char *end = line + linelen;
	  char *dst;
          char **aline = &uiserver->colon.attic.line;
	  int *alinelen = &uiserver->colon.attic.linelen;

	  if (uiserver->colon.attic.linesize < *alinelen + linelen + 1)
	    {
	      char *newline = realloc (*aline, *alinelen + linelen + 1);
	      if (!newline)
		err = gpg_error_from_errno (errno);
	      else
		{
		  *aline = newline;
		  uiserver->colon.attic.linesize = *alinelen + linelen + 1;
		}
	    }
	  if (!err)
	    {
	      dst = *aline + *alinelen;

	      while (!err && src < end)
		{
		  if (*src == '%' && src + 2 < end)
		    {
		      /* Handle escaped characters.  */
		      ++src;
		      *dst = _gpgme_hextobyte (src);
		      (*alinelen)++;
		      src += 2;
		    }
		  else
		    {
		      *dst = *src++;
		      (*alinelen)++;
		    }
		  
		  if (*dst == '\n')
		    {
		      /* Terminate the pending line, pass it to the colon
			 handler and reset it.  */
		      
		      uiserver->colon.any = 1;
		      if (*alinelen > 1 && *(dst - 1) == '\r')
			dst--;
		      *dst = '\0';

		      /* FIXME How should we handle the return code?  */
		      err = uiserver->colon.fnc (uiserver->colon.fnc_value, *aline);
		      if (!err)
			{
			  dst = *aline;
			  *alinelen = 0;
			}
		    }
		  else
		    dst++;
		}
	    }
          TRACE2 (DEBUG_CTX, "gpgme:status_handler", uiserver,
		  "fd 0x%x: D line; final status: %s",
                  fd, err? gpg_strerror (err):"ok");
        }
      else if (linelen > 2
	       && line[0] == 'D' && line[1] == ' '
	       && uiserver->inline_data)
        {
          char *src = line + 2;
	  char *end = line + linelen;
	  char *dst = src;
          ssize_t nwritten;

          linelen = 0;
          while (src < end)
            {
              if (*src == '%' && src + 2 < end)
                {
                  /* Handle escaped characters.  */
                  ++src;
                  *dst++ = _gpgme_hextobyte (src);
                  src += 2;
                }
              else
                *dst++ = *src++;
              
              linelen++;
            }
          
          src = line + 2;
          while (linelen > 0)
            {
              nwritten = gpgme_data_write (uiserver->inline_data, src, linelen);
              if (!nwritten || (nwritten < 0 && errno != EINTR)
                  || nwritten > linelen)
                {
                  err = gpg_error_from_errno (errno);
                  break;
                }
              src += nwritten;
              linelen -= nwritten;
            }

          TRACE2 (DEBUG_CTX, "gpgme:status_handler", uiserver,
		  "fd 0x%x: D inlinedata; final status: %s",
                  fd, err? gpg_strerror (err):"ok");
        }
      else if (linelen > 2
	       && line[0] == 'S' && line[1] == ' ')
	{
	  char *rest;
	  gpgme_status_code_t r;
	  
	  rest = strchr (line + 2, ' ');
	  if (!rest)
	    rest = line + linelen; /* set to an empty string */
	  else
	    *(rest++) = 0;

	  r = _gpgme_parse_status (line + 2);

	  if (r >= 0)
	    {
	      if (uiserver->status.fnc)
		err = uiserver->status.fnc (uiserver->status.fnc_value, r, rest);
	    }
	  else
	    fprintf (stderr, "[UNKNOWN STATUS]%s %s", line + 2, rest);
          TRACE3 (DEBUG_CTX, "gpgme:status_handler", uiserver,
		  "fd 0x%x: S line (%s) - final status: %s",
                  fd, line+2, err? gpg_strerror (err):"ok");
	}
      else if (linelen >= 7
               && line[0] == 'I' && line[1] == 'N' && line[2] == 'Q'
               && line[3] == 'U' && line[4] == 'I' && line[5] == 'R'
               && line[6] == 'E' 
               && (line[7] == '\0' || line[7] == ' '))
        {
          char *keyword = line+7;

          while (*keyword == ' ')
            keyword++;;
          default_inq_cb (uiserver, keyword);
          assuan_write_line (uiserver->assuan_ctx, "END");
        }

    }
  while (!err && assuan_pending_line (uiserver->assuan_ctx));
	  
  return err;
}


static gpgme_error_t
add_io_cb (engine_uiserver_t uiserver, iocb_data_t *iocbd, gpgme_io_cb_t handler)
{
  gpgme_error_t err;

  TRACE_BEG2 (DEBUG_ENGINE, "engine-uiserver:add_io_cb", uiserver,
              "fd %d, dir %d", iocbd->fd, iocbd->dir);
  err = (*uiserver->io_cbs.add) (uiserver->io_cbs.add_priv,
			      iocbd->fd, iocbd->dir,
			      handler, iocbd->data, &iocbd->tag);
  if (err)
    return TRACE_ERR (err);
  if (!iocbd->dir)
    /* FIXME Kludge around poll() problem.  */
    err = _gpgme_io_set_nonblocking (iocbd->fd);
  return TRACE_ERR (err);
}


static gpgme_error_t
start (engine_uiserver_t uiserver, const char *command)
{
  gpgme_error_t err;
  int fdlist[5];
  int nfds;

  /* We need to know the fd used by assuan for reads.  We do this by
     using the assumption that the first returned fd from
     assuan_get_active_fds() is always this one.  */
  nfds = assuan_get_active_fds (uiserver->assuan_ctx, 0 /* read fds */,
                                fdlist, DIM (fdlist));
  if (nfds < 1)
    return gpg_error (GPG_ERR_GENERAL);	/* FIXME */

  /* We "duplicate" the file descriptor, so we can close it here (we
     can't close fdlist[0], as that is closed by libassuan, and
     closing it here might cause libassuan to close some unrelated FD
     later).  Alternatively, we could special case status_fd and
     register/unregister it manually as needed, but this increases
     code duplication and is more complicated as we can not use the
     close notifications etc.  A third alternative would be to let
     Assuan know that we closed the FD, but that complicates the
     Assuan interface.  */

  uiserver->status_cb.fd = _gpgme_io_dup (fdlist[0]);
  if (uiserver->status_cb.fd < 0)
    return gpg_error_from_syserror ();

  if (_gpgme_io_set_close_notify (uiserver->status_cb.fd,
				  close_notify_handler, uiserver))
    {
      _gpgme_io_close (uiserver->status_cb.fd);
      uiserver->status_cb.fd = -1;
      return gpg_error (GPG_ERR_GENERAL);
    }

  err = add_io_cb (uiserver, &uiserver->status_cb, status_handler);
  if (!err && uiserver->input_cb.fd != -1)
    err = add_io_cb (uiserver, &uiserver->input_cb, _gpgme_data_outbound_handler);
  if (!err && uiserver->output_cb.fd != -1)
    err = add_io_cb (uiserver, &uiserver->output_cb, _gpgme_data_inbound_handler);
  if (!err && uiserver->message_cb.fd != -1)
    err = add_io_cb (uiserver, &uiserver->message_cb, _gpgme_data_outbound_handler);

  if (!err)
    err = assuan_write_line (uiserver->assuan_ctx, command);

  if (!err)
    uiserver_io_event (uiserver, GPGME_EVENT_START, NULL);

  return err;
}


static gpgme_error_t
uiserver_reset (void *engine)
{
  engine_uiserver_t uiserver = engine;

  /* We must send a reset because we need to reset the list of
     signers.  Note that RESET does not reset OPTION commands. */
  return uiserver_assuan_simple_command (uiserver->assuan_ctx, "RESET", NULL, NULL);
}


static gpgme_error_t
_uiserver_decrypt (void *engine, int verify,
		   gpgme_data_t ciph, gpgme_data_t plain)
{
  engine_uiserver_t uiserver = engine;
  gpgme_error_t err;
  const char *protocol;
  char *cmd;

  if (!uiserver)
    return gpg_error (GPG_ERR_INV_VALUE);
  if (uiserver->protocol == GPGME_PROTOCOL_DEFAULT)
    protocol = "";
  else if (uiserver->protocol == GPGME_PROTOCOL_OpenPGP)
    protocol = " --protocol=OpenPGP";
  else if (uiserver->protocol == GPGME_PROTOCOL_CMS)
    protocol = " --protocol=CMS";
  else
    return gpgme_error (GPG_ERR_UNSUPPORTED_PROTOCOL);

  if (asprintf (&cmd, "DECRYPT%s%s", protocol,
		verify ? "" : " --no-verify") < 0)
    return gpg_error_from_errno (errno);

  uiserver->input_cb.data = ciph;
  err = uiserver_set_fd (uiserver, INPUT_FD,
			 map_data_enc (uiserver->input_cb.data));
  if (err)
    {
      free (cmd);
      return gpg_error (GPG_ERR_GENERAL);	/* FIXME */
    }
  uiserver->output_cb.data = plain;
  err = uiserver_set_fd (uiserver, OUTPUT_FD, 0);
  if (err)
    {
      free (cmd);
      return gpg_error (GPG_ERR_GENERAL);	/* FIXME */
    }
  uiserver->inline_data = NULL;

  err = start (engine, cmd);
  free (cmd);
  return err;
}


static gpgme_error_t
uiserver_decrypt (void *engine, gpgme_data_t ciph, gpgme_data_t plain)
{
  return _uiserver_decrypt (engine, 0, ciph, plain);
}


static gpgme_error_t
uiserver_decrypt_verify (void *engine, gpgme_data_t ciph, gpgme_data_t plain)
{
  return _uiserver_decrypt (engine, 1, ciph, plain);
}


static gpgme_error_t
set_recipients (engine_uiserver_t uiserver, gpgme_key_t recp[])
{
  gpgme_error_t err = 0;
  assuan_context_t ctx = uiserver->assuan_ctx;
  char *line;
  int linelen;
  int invalid_recipients = 0;
  int i;

  linelen = 10 + 40 + 1;	/* "RECIPIENT " + guess + '\0'.  */
  line = malloc (10 + 40 + 1);
  if (!line)
    return gpg_error_from_errno (errno);
  strcpy (line, "RECIPIENT ");
  for (i=0; !err && recp[i]; i++)
    {
      char *uid;
      int newlen;

      /* We use only the first user ID of the key.  */
      if (!recp[i]->uids || !(uid=recp[i]->uids->uid) || !*uid)
	{
	  invalid_recipients++;
	  continue;
	}

      newlen = 11 + strlen (uid);
      if (linelen < newlen)
	{
	  char *newline = realloc (line, newlen);
	  if (! newline)
	    {
	      int saved_errno = errno;
	      free (line);
	      return gpg_error_from_errno (saved_errno);
	    }
	  line = newline;
	  linelen = newlen;
	}
      /* FIXME: need to do proper escaping  */
      strcpy (&line[10], uid);

      err = uiserver_assuan_simple_command (ctx, line, uiserver->status.fnc,
                                            uiserver->status.fnc_value);
      /* FIXME: This might requires more work.  */
      if (gpg_err_code (err) == GPG_ERR_NO_PUBKEY)
	invalid_recipients++;
      else if (err)
	{
	  free (line);
	  return err;
	}
    }
  free (line);
  return gpg_error (invalid_recipients
		    ? GPG_ERR_UNUSABLE_PUBKEY : GPG_ERR_NO_ERROR);
}


static gpgme_error_t
uiserver_encrypt (void *engine, gpgme_key_t recp[], gpgme_encrypt_flags_t flags,
		  gpgme_data_t plain, gpgme_data_t ciph, int use_armor)
{
  engine_uiserver_t uiserver = engine;
  gpgme_error_t err;
  const char *protocol;
  char *cmd;

  if (!uiserver)
    return gpg_error (GPG_ERR_INV_VALUE);
  if (uiserver->protocol == GPGME_PROTOCOL_DEFAULT)
    protocol = "";
  else if (uiserver->protocol == GPGME_PROTOCOL_OpenPGP)
    protocol = " --protocol=OpenPGP";
  else if (uiserver->protocol == GPGME_PROTOCOL_CMS)
    protocol = " --protocol=CMS";
  else
    return gpgme_error (GPG_ERR_UNSUPPORTED_PROTOCOL);

  if (flags & GPGME_ENCRYPT_PREPARE)
    {
      if (!recp || plain || ciph)
	return gpg_error (GPG_ERR_INV_VALUE);

      if (asprintf (&cmd, "PREP_ENCRYPT%s%s", protocol,
		    (flags & GPGME_ENCRYPT_EXPECT_SIGN)
		    ? " --expect-sign" : "") < 0)
	return gpg_error_from_errno (errno);
    }
  else
    {
      if (!plain || !ciph)
	return gpg_error (GPG_ERR_INV_VALUE);

      if (asprintf (&cmd, "ENCRYPT%s", protocol) < 0)
	return gpg_error_from_errno (errno);
    }

  if (plain)
    {
      uiserver->input_cb.data = plain;
      err = uiserver_set_fd (uiserver, INPUT_FD,
			     map_data_enc (uiserver->input_cb.data));
      if (err)
	{
	  free (cmd);
	  return err;
	}
    }
    
  if (ciph)
    {
      uiserver->output_cb.data = ciph;
      err = uiserver_set_fd (uiserver, OUTPUT_FD, use_armor ? "--armor"
			     : map_data_enc (uiserver->output_cb.data));
      if (err)
	{
	  free (cmd);
	  return err;
	}
    }

  uiserver->inline_data = NULL;

  if (recp)
    {
      err = set_recipients (uiserver, recp);
      if (err)
	{
	  free (cmd);
	  return err;
	}
    }

  err = start (uiserver, cmd);
  free (cmd);
  return err;
}


static gpgme_error_t
uiserver_sign (void *engine, gpgme_data_t in, gpgme_data_t out,
	       gpgme_sig_mode_t mode, int use_armor, int use_textmode,
	       int include_certs, gpgme_ctx_t ctx /* FIXME */)
{
  engine_uiserver_t uiserver = engine;
  gpgme_error_t err = 0;
  const char *protocol;
  char *cmd;
  gpgme_key_t key;

  if (!uiserver || !in || !out)
    return gpg_error (GPG_ERR_INV_VALUE);
  if (uiserver->protocol == GPGME_PROTOCOL_DEFAULT)
    protocol = "";
  else if (uiserver->protocol == GPGME_PROTOCOL_OpenPGP)
    protocol = " --protocol=OpenPGP";
  else if (uiserver->protocol == GPGME_PROTOCOL_CMS)
    protocol = " --protocol=CMS";
  else
    return gpgme_error (GPG_ERR_UNSUPPORTED_PROTOCOL);

  if (asprintf (&cmd, "SIGN%s%s", protocol,
		(mode == GPGME_SIG_MODE_DETACH) ? " --detached" : "") < 0)
    return gpg_error_from_errno (errno);

  key = gpgme_signers_enum (ctx, 0);
  if (key)
    {
      const char *s = NULL;
      
      if (key && key->uids)
        s = key->uids->email;
      
      if (s && strlen (s) < 80)
        {
          char buf[100];
          
          strcpy (stpcpy (buf, "SENDER --info "), s);
          err = uiserver_assuan_simple_command (uiserver->assuan_ctx, buf,
                                                uiserver->status.fnc,
                                                uiserver->status.fnc_value);
        }
      else
        err = gpg_error (GPG_ERR_INV_VALUE);
      gpgme_key_unref (key);
      if (err) 
      {
	free (cmd);
	return err;
      }
  }

  uiserver->input_cb.data = in;
  err = uiserver_set_fd (uiserver, INPUT_FD,
			 map_data_enc (uiserver->input_cb.data));
  if (err)
    {
      free (cmd);
      return err;
    }
  uiserver->output_cb.data = out;
  err = uiserver_set_fd (uiserver, OUTPUT_FD, use_armor ? "--armor"
			 : map_data_enc (uiserver->output_cb.data));
  if (err)
    {
      free (cmd);
      return err;
    }
  uiserver->inline_data = NULL;

  err = start (uiserver, cmd);
  free (cmd);
  return err;
}


/* FIXME: Missing a way to specify --silent.  */
static gpgme_error_t
uiserver_verify (void *engine, gpgme_data_t sig, gpgme_data_t signed_text,
	      gpgme_data_t plaintext)
{
  engine_uiserver_t uiserver = engine;
  gpgme_error_t err;
  const char *protocol;
  char *cmd;

  if (!uiserver)
    return gpg_error (GPG_ERR_INV_VALUE);
  if (uiserver->protocol == GPGME_PROTOCOL_DEFAULT)
    protocol = "";
  else if (uiserver->protocol == GPGME_PROTOCOL_OpenPGP)
    protocol = " --protocol=OpenPGP";
  else if (uiserver->protocol == GPGME_PROTOCOL_CMS)
    protocol = " --protocol=CMS";
  else
    return gpgme_error (GPG_ERR_UNSUPPORTED_PROTOCOL);

  if (asprintf (&cmd, "VERIFY%s", protocol) < 0)
    return gpg_error_from_errno (errno);

  uiserver->input_cb.data = sig;
  err = uiserver_set_fd (uiserver, INPUT_FD,
			 map_data_enc (uiserver->input_cb.data));
  if (err)
    {
      free (cmd);
      return err;
    }
  if (plaintext)
    {
      /* Normal or cleartext signature.  */
      uiserver->output_cb.data = plaintext;
      err = uiserver_set_fd (uiserver, OUTPUT_FD, 0);
    }
  else
    {
      /* Detached signature.  */
      uiserver->message_cb.data = signed_text;
      err = uiserver_set_fd (uiserver, MESSAGE_FD, 0);
    }
  uiserver->inline_data = NULL;

  if (!err)
    err = start (uiserver, cmd);

  free (cmd);
  return err;
}


static void
uiserver_set_status_handler (void *engine, engine_status_handler_t fnc,
			  void *fnc_value) 
{
  engine_uiserver_t uiserver = engine;

  uiserver->status.fnc = fnc;
  uiserver->status.fnc_value = fnc_value;
}


static gpgme_error_t
uiserver_set_colon_line_handler (void *engine, engine_colon_line_handler_t fnc,
			      void *fnc_value) 
{
  engine_uiserver_t uiserver = engine;

  uiserver->colon.fnc = fnc;
  uiserver->colon.fnc_value = fnc_value;
  uiserver->colon.any = 0;
  return 0;
}


static void
uiserver_set_io_cbs (void *engine, gpgme_io_cbs_t io_cbs)
{
  engine_uiserver_t uiserver = engine;
  uiserver->io_cbs = *io_cbs;
}


static void
uiserver_io_event (void *engine, gpgme_event_io_t type, void *type_data)
{
  engine_uiserver_t uiserver = engine;

  TRACE3 (DEBUG_ENGINE, "gpgme:uiserver_io_event", uiserver,
          "event %p, type %d, type_data %p",
          uiserver->io_cbs.event, type, type_data);
  if (uiserver->io_cbs.event)
    (*uiserver->io_cbs.event) (uiserver->io_cbs.event_priv, type, type_data);
}


struct engine_ops _gpgme_engine_ops_uiserver =
  {
    /* Static functions.  */
    _gpgme_get_uiserver_socket_path,
    NULL,
    uiserver_get_version,
    uiserver_get_req_version,
    uiserver_new,

    /* Member functions.  */
    uiserver_release,
    uiserver_reset,
    uiserver_set_status_handler,
    NULL,		/* set_command_handler */
    uiserver_set_colon_line_handler,
    uiserver_set_locale,
    uiserver_set_protocol,
    uiserver_decrypt,
    uiserver_decrypt_verify,
    NULL,		/* delete */
    NULL,		/* edit */
    uiserver_encrypt,
    NULL,		/* encrypt_sign */
    NULL,		/* export */
    NULL,		/* export_ext */
    NULL,		/* genkey */
    NULL,		/* import */
    NULL,		/* keylist */
    NULL,		/* keylist_ext */
    uiserver_sign,
    NULL,		/* trustlist */
    uiserver_verify,
    NULL,		/* getauditlog */
    NULL,               /* opassuan_transact */
    NULL,		/* conf_load */
    NULL,		/* conf_save */
    uiserver_set_io_cbs,
    uiserver_io_event,
    uiserver_cancel,
    NULL		/* cancel_op */
  };