sm/call-agent.c

   1 /* call-agent.c - Divert GPGSM operations to the agent
   2  * Copyright (C) 2001, 2002, 2003, 2005, 2007,
   3  *               2008, 2009 Free Software Foundation, Inc.
   4  *
   5  * This file is part of GnuPG.
   6  *
   7  * GnuPG is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * GnuPG is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <errno.h>
  26 #include <unistd.h>
  27 #include <time.h>
  28 #include <assert.h>
  29 #ifdef HAVE_LOCALE_H
  30 #include <locale.h>
  31 #endif
  32
  33 #include "gpgsm.h"
  34 #include <gcrypt.h>
  35 #include <assuan.h>
  36 #include "i18n.h"
  37 #include "asshelp.h"
  38 #include "keydb.h" /* fixme: Move this to import.c */
  39 #include "membuf.h"
  40
  41
  42 static assuan_context_t agent_ctx = NULL;
  43
  44
  45 struct cipher_parm_s
  46 {
  47   ctrl_t ctrl;
  48   assuan_context_t ctx;
  49   const unsigned char *ciphertext;
  50   size_t ciphertextlen;
  51 };
  52
  53 struct genkey_parm_s
  54 {
  55   ctrl_t ctrl;
  56   assuan_context_t ctx;
  57   const unsigned char *sexp;
  58   size_t sexplen;
  59 };
  60
  61 struct learn_parm_s
  62 {
  63   int error;
  64   ctrl_t ctrl;
  65   assuan_context_t ctx;
  66   membuf_t *data;
  67 };
  68
  69
  70 \f
  71 /* Try to connect to the agent via socket or fork it off and work by
  72    pipes.  Handle the server's initial greeting */
  73 static int
  74 start_agent (ctrl_t ctrl)
  75 {
  76   int rc;
  77
  78   if (agent_ctx)
  79     rc = 0;      /* fixme: We need a context for each thread or
  80                     serialize the access to the agent (which is
  81                     suitable given that the agent is not MT. */
  82   else
  83     {
  84       rc = start_new_gpg_agent (&agent_ctx,
  85                                 GPG_ERR_SOURCE_DEFAULT,
  86                                 opt.homedir,
  87                                 opt.agent_program,
  88                                 opt.lc_ctype, opt.lc_messages,
  89                                 opt.session_env,
  90                                 opt.verbose, DBG_ASSUAN,
  91                                 gpgsm_status2, ctrl);
  92
  93       if (!rc)
  94         {
  95           /* Tell the agent that we support Pinentry notifications.  No
  96              error checking so that it will work also with older
  97              agents.  */
  98           assuan_transact (agent_ctx, "OPTION allow-pinentry-notify",
  99                            NULL, NULL, NULL, NULL, NULL, NULL);
 100         }
 101     }
 102
 103   if (!ctrl->agent_seen)
 104     {
 105       ctrl->agent_seen = 1;
 106       audit_log_ok (ctrl->audit, AUDIT_AGENT_READY, rc);
 107     }
 108
 109   return rc;
 110 }
 111
 112
 113
 114 static gpg_error_t
 115 membuf_data_cb (void *opaque, const void *buffer, size_t length)
 116 {
 117   membuf_t *data = opaque;
 118
 119   if (buffer)
 120     put_membuf (data, buffer, length);
 121   return 0;
 122 }
 123
 124
 125 /* This is the default inquiry callback.  It mainly handles the
 126    Pinentry notifications.  */
 127 static gpg_error_t
 128 default_inq_cb (void *opaque, const char *line)
 129 {
 130   gpg_error_t err;
 131   ctrl_t ctrl = opaque;
 132
 133   if (!strncmp (line, "PINENTRY_LAUNCHED", 17) && (line[17]==' '||!line[17]))
 134     {
 135       err = gpgsm_proxy_pinentry_notify (ctrl, line);
 136       if (err)
 137         log_error (_("failed to proxy %s inquiry to client\n"),
 138                    "PINENTRY_LAUNCHED");
 139       /* We do not pass errors to avoid breaking other code.  */
 140     }
 141   else
 142     log_error ("ignoring gpg-agent inquiry `%s'\n", line);
 143
 144   return 0;
 145 }
 146
 147
 148
 149 \f
 150 /* Call the agent to do a sign operation using the key identified by
 151    the hex string KEYGRIP. */
 152 int
 153 gpgsm_agent_pksign (ctrl_t ctrl, const char *keygrip, const char *desc,
 154                     unsigned char *digest, size_t digestlen, int digestalgo,
 155                     unsigned char **r_buf, size_t *r_buflen )
 156 {
 157   int rc, i;
 158   char *p, line[ASSUAN_LINELENGTH];
 159   membuf_t data;
 160   size_t len;
 161
 162   *r_buf = NULL;
 163   rc = start_agent (ctrl);
 164   if (rc)
 165     return rc;
 166
 167   if (digestlen*2 + 50 > DIM(line))
 168     return gpg_error (GPG_ERR_GENERAL);
 169
 170   rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
 171   if (rc)
 172     return rc;
 173
 174   snprintf (line, DIM(line)-1, "SIGKEY %s", keygrip);
 175   line[DIM(line)-1] = 0;
 176   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 177   if (rc)
 178     return rc;
 179
 180   if (desc)
 181     {
 182       snprintf (line, DIM(line)-1, "SETKEYDESC %s", desc);
 183       line[DIM(line)-1] = 0;
 184       rc = assuan_transact (agent_ctx, line,
 185                             NULL, NULL, NULL, NULL, NULL, NULL);
 186       if (rc)
 187         return rc;
 188     }
 189
 190   sprintf (line, "SETHASH %d ", digestalgo);
 191   p = line + strlen (line);
 192   for (i=0; i < digestlen ; i++, p += 2 )
 193     sprintf (p, "%02X", digest[i]);
 194   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 195   if (rc)
 196     return rc;
 197
 198   init_membuf (&data, 1024);
 199   rc = assuan_transact (agent_ctx, "PKSIGN",
 200                         membuf_data_cb, &data, default_inq_cb, ctrl,
 201                         NULL, NULL);
 202   if (rc)
 203     {
 204       xfree (get_membuf (&data, &len));
 205       return rc;
 206     }
 207   *r_buf = get_membuf (&data, r_buflen);
 208
 209   if (!gcry_sexp_canon_len (*r_buf, *r_buflen, NULL, NULL))
 210     {
 211       xfree (*r_buf); *r_buf = NULL;
 212       return gpg_error (GPG_ERR_INV_VALUE);
 213     }
 214
 215   return *r_buf? 0 : out_of_core ();
 216 }
 217
 218
 219 /* Call the scdaemon to do a sign operation using the key identified by
 220    the hex string KEYID. */
 221 int
 222 gpgsm_scd_pksign (ctrl_t ctrl, const char *keyid, const char *desc,
 223                   unsigned char *digest, size_t digestlen, int digestalgo,
 224                   unsigned char **r_buf, size_t *r_buflen )
 225 {
 226   int rc, i;
 227   char *p, line[ASSUAN_LINELENGTH];
 228   membuf_t data;
 229   size_t len;
 230   const char *hashopt;
 231   unsigned char *sigbuf;
 232   size_t sigbuflen;
 233
 234   (void)desc;
 235
 236   *r_buf = NULL;
 237
 238   switch(digestalgo)
 239     {
 240     case GCRY_MD_SHA1:  hashopt = "--hash=sha1"; break;
 241     case GCRY_MD_RMD160:hashopt = "--hash=rmd160"; break;
 242     case GCRY_MD_MD5:   hashopt = "--hash=md5"; break;
 243     case GCRY_MD_SHA256:hashopt = "--hash=sha256"; break;
 244     default:
 245       return gpg_error (GPG_ERR_DIGEST_ALGO);
 246     }
 247
 248   rc = start_agent (ctrl);
 249   if (rc)
 250     return rc;
 251
 252   if (digestlen*2 + 50 > DIM(line))
 253     return gpg_error (GPG_ERR_GENERAL);
 254
 255   p = stpcpy (line, "SCD SETDATA " );
 256   for (i=0; i < digestlen ; i++, p += 2 )
 257     sprintf (p, "%02X", digest[i]);
 258   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 259   if (rc)
 260     return rc;
 261
 262   init_membuf (&data, 1024);
 263
 264   snprintf (line, DIM(line)-1, "SCD PKSIGN %s %s", hashopt, keyid);
 265   line[DIM(line)-1] = 0;
 266   rc = assuan_transact (agent_ctx, line,
 267                         membuf_data_cb, &data, default_inq_cb, ctrl,
 268                         NULL, NULL);
 269   if (rc)
 270     {
 271       xfree (get_membuf (&data, &len));
 272       return rc;
 273     }
 274   sigbuf = get_membuf (&data, &sigbuflen);
 275
 276   /* Create an S-expression from it which is formatted like this:
 277      "(7:sig-val(3:rsa(1:sSIGBUFLEN:SIGBUF)))" Fixme: If a card ever
 278      creates non-RSA keys we need to change things. */
 279   *r_buflen = 21 + 11 + sigbuflen + 4;
 280   p = xtrymalloc (*r_buflen);
 281   *r_buf = (unsigned char*)p;
 282   if (!p)
 283     {
 284       xfree (sigbuf);
 285       return 0;
 286     }
 287   p = stpcpy (p, "(7:sig-val(3:rsa(1:s" );
 288   sprintf (p, "%u:", (unsigned int)sigbuflen);
 289   p += strlen (p);
 290   memcpy (p, sigbuf, sigbuflen);
 291   p += sigbuflen;
 292   strcpy (p, ")))");
 293   xfree (sigbuf);
 294
 295   assert (gcry_sexp_canon_len (*r_buf, *r_buflen, NULL, NULL));
 296   return  0;
 297 }
 298
 299
 300
 301 \f
 302 /* Handle a CIPHERTEXT inquiry.  Note, we only send the data,
 303    assuan_transact talkes care of flushing and writing the end */
 304 static gpg_error_t
 305 inq_ciphertext_cb (void *opaque, const char *line)
 306 {
 307   struct cipher_parm_s *parm = opaque;
 308   int rc;
 309
 310   if (!strncmp (line, "CIPHERTEXT", 10) && (line[10]==' '||!line[10]))
 311     {
 312       assuan_begin_confidential (parm->ctx);
 313       rc = assuan_send_data (parm->ctx, parm->ciphertext, parm->ciphertextlen);
 314       assuan_end_confidential (parm->ctx);
 315     }
 316   else
 317     rc = default_inq_cb (parm->ctrl, line);
 318
 319   return rc;
 320 }
 321
 322
 323 /* Call the agent to do a decrypt operation using the key identified by
 324    the hex string KEYGRIP. */
 325 int
 326 gpgsm_agent_pkdecrypt (ctrl_t ctrl, const char *keygrip, const char *desc,
 327                        ksba_const_sexp_t ciphertext,
 328                        char **r_buf, size_t *r_buflen )
 329 {
 330   int rc;
 331   char line[ASSUAN_LINELENGTH];
 332    membuf_t data;
 333   struct cipher_parm_s cipher_parm;
 334   size_t n, len;
 335   char *p, *buf, *endp;
 336   size_t ciphertextlen;
 337
 338   if (!keygrip || strlen(keygrip) != 40 || !ciphertext || !r_buf || !r_buflen)
 339     return gpg_error (GPG_ERR_INV_VALUE);
 340   *r_buf = NULL;
 341
 342   ciphertextlen = gcry_sexp_canon_len (ciphertext, 0, NULL, NULL);
 343   if (!ciphertextlen)
 344     return gpg_error (GPG_ERR_INV_VALUE);
 345
 346   rc = start_agent (ctrl);
 347   if (rc)
 348     return rc;
 349
 350   rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
 351   if (rc)
 352     return rc;
 353
 354   assert ( DIM(line) >= 50 );
 355   snprintf (line, DIM(line)-1, "SETKEY %s", keygrip);
 356   line[DIM(line)-1] = 0;
 357   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 358   if (rc)
 359     return rc;
 360
 361   if (desc)
 362     {
 363       snprintf (line, DIM(line)-1, "SETKEYDESC %s", desc);
 364       line[DIM(line)-1] = 0;
 365       rc = assuan_transact (agent_ctx, line,
 366                             NULL, NULL, NULL, NULL, NULL, NULL);
 367       if (rc)
 368         return rc;
 369     }
 370
 371   init_membuf (&data, 1024);
 372   cipher_parm.ctrl = ctrl;
 373   cipher_parm.ctx = agent_ctx;
 374   cipher_parm.ciphertext = ciphertext;
 375   cipher_parm.ciphertextlen = ciphertextlen;
 376   rc = assuan_transact (agent_ctx, "PKDECRYPT",
 377                         membuf_data_cb, &data,
 378                         inq_ciphertext_cb, &cipher_parm, NULL, NULL);
 379   if (rc)
 380     {
 381       xfree (get_membuf (&data, &len));
 382       return rc;
 383     }
 384
 385   put_membuf (&data, "", 1); /* Make sure it is 0 terminated. */
 386   buf = get_membuf (&data, &len);
 387   if (!buf)
 388     return gpg_error (GPG_ERR_ENOMEM);
 389   assert (len); /* (we forced Nul termination.)  */
 390
 391   if (*buf == '(')
 392     {
 393       if (len < 13 || memcmp (buf, "(5:value", 8) ) /* "(5:valueN:D)\0" */
 394         return gpg_error (GPG_ERR_INV_SEXP);
 395       len -= 11;   /* Count only the data of the second part. */
 396       p = buf + 8; /* Skip leading parenthesis and the value tag. */
 397     }
 398   else
 399     {
 400       /* For compatibility with older gpg-agents handle the old style
 401          incomplete S-exps. */
 402       len--;      /* Do not count the Nul. */
 403       p = buf;
 404     }
 405
 406   n = strtoul (p, &endp, 10);
 407   if (!n || *endp != ':')
 408     return gpg_error (GPG_ERR_INV_SEXP);
 409   endp++;
 410   if (endp-p+n > len)
 411     return gpg_error (GPG_ERR_INV_SEXP); /* Oops: Inconsistent S-Exp. */
 412
 413   memmove (buf, endp, n);
 414
 415   *r_buflen = n;
 416   *r_buf = buf;
 417   return 0;
 418 }
 419
 420
 421
 422
 423 \f
 424 /* Handle a KEYPARMS inquiry.  Note, we only send the data,
 425    assuan_transact takes care of flushing and writing the end */
 426 static gpg_error_t
 427 inq_genkey_parms (void *opaque, const char *line)
 428 {
 429   struct genkey_parm_s *parm = opaque;
 430   int rc;
 431
 432   if (!strncmp (line, "KEYPARAM", 8) && (line[8]==' '||!line[8]))
 433     {
 434       rc = assuan_send_data (parm->ctx, parm->sexp, parm->sexplen);
 435     }
 436   else
 437     rc = default_inq_cb (parm->ctrl, line);
 438
 439   return rc;
 440 }
 441
 442
 443 \f
 444 /* Call the agent to generate a newkey */
 445 int
 446 gpgsm_agent_genkey (ctrl_t ctrl,
 447                     ksba_const_sexp_t keyparms, ksba_sexp_t *r_pubkey)
 448 {
 449   int rc;
 450   struct genkey_parm_s gk_parm;
 451   membuf_t data;
 452   size_t len;
 453   unsigned char *buf;
 454
 455   *r_pubkey = NULL;
 456   rc = start_agent (ctrl);
 457   if (rc)
 458     return rc;
 459
 460   rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
 461   if (rc)
 462     return rc;
 463
 464   init_membuf (&data, 1024);
 465   gk_parm.ctrl = ctrl;
 466   gk_parm.ctx = agent_ctx;
 467   gk_parm.sexp = keyparms;
 468   gk_parm.sexplen = gcry_sexp_canon_len (keyparms, 0, NULL, NULL);
 469   if (!gk_parm.sexplen)
 470     return gpg_error (GPG_ERR_INV_VALUE);
 471   rc = assuan_transact (agent_ctx, "GENKEY",
 472                         membuf_data_cb, &data,
 473                         inq_genkey_parms, &gk_parm, NULL, NULL);
 474   if (rc)
 475     {
 476       xfree (get_membuf (&data, &len));
 477       return rc;
 478     }
 479   buf = get_membuf (&data, &len);
 480   if (!buf)
 481     return gpg_error (GPG_ERR_ENOMEM);
 482   if (!gcry_sexp_canon_len (buf, len, NULL, NULL))
 483     {
 484       xfree (buf);
 485       return gpg_error (GPG_ERR_INV_SEXP);
 486     }
 487   *r_pubkey = buf;
 488   return 0;
 489 }
 490
 491 \f
 492 /* Call the agent to read the public key part for a given keygrip.  If
 493    FROMCARD is true, the key is directly read from the current
 494    smartcard. In this case HEXKEYGRIP should be the keyID
 495    (e.g. OPENPGP.3). */
 496 int
 497 gpgsm_agent_readkey (ctrl_t ctrl, int fromcard, const char *hexkeygrip,
 498                      ksba_sexp_t *r_pubkey)
 499 {
 500   int rc;
 501   membuf_t data;
 502   size_t len;
 503   unsigned char *buf;
 504   char line[ASSUAN_LINELENGTH];
 505
 506   *r_pubkey = NULL;
 507   rc = start_agent (ctrl);
 508   if (rc)
 509     return rc;
 510
 511   rc = assuan_transact (agent_ctx, "RESET",NULL, NULL, NULL, NULL, NULL, NULL);
 512   if (rc)
 513     return rc;
 514
 515   snprintf (line, DIM(line)-1, "%sREADKEY %s",
 516             fromcard? "SCD ":"", hexkeygrip);
 517   line[DIM(line)-1] = 0;
 518
 519   init_membuf (&data, 1024);
 520   rc = assuan_transact (agent_ctx, line,
 521                         membuf_data_cb, &data,
 522                         default_inq_cb, ctrl, NULL, NULL);
 523   if (rc)
 524     {
 525       xfree (get_membuf (&data, &len));
 526       return rc;
 527     }
 528   buf = get_membuf (&data, &len);
 529   if (!buf)
 530     return gpg_error (GPG_ERR_ENOMEM);
 531   if (!gcry_sexp_canon_len (buf, len, NULL, NULL))
 532     {
 533       xfree (buf);
 534       return gpg_error (GPG_ERR_INV_SEXP);
 535     }
 536   *r_pubkey = buf;
 537   return 0;
 538 }
 539
 540
 541 \f
 542 /* Take the serial number from LINE and return it verbatim in a newly
 543    allocated string.  We make sure that only hex characters are
 544    returned. */
 545 static char *
 546 store_serialno (const char *line)
 547 {
 548   const char *s;
 549   char *p;
 550
 551   for (s=line; hexdigitp (s); s++)
 552     ;
 553   p = xtrymalloc (s + 1 - line);
 554   if (p)
 555     {
 556       memcpy (p, line, s-line);
 557       p[s-line] = 0;
 558     }
 559   return p;
 560 }
 561
 562
 563 /* Callback for the gpgsm_agent_serialno fucntion.  */
 564 static gpg_error_t
 565 scd_serialno_status_cb (void *opaque, const char *line)
 566 {
 567   char **r_serialno = opaque;
 568   const char *keyword = line;
 569   int keywordlen;
 570
 571   for (keywordlen=0; *line && !spacep (line); line++, keywordlen++)
 572     ;
 573   while (spacep (line))
 574     line++;
 575
 576   if (keywordlen == 8 && !memcmp (keyword, "SERIALNO", keywordlen))
 577     {
 578       xfree (*r_serialno);
 579       *r_serialno = store_serialno (line);
 580     }
 581
 582   return 0;
 583 }
 584
 585
 586 /* Call the agent to read the serial number of the current card.  */
 587 int
 588 gpgsm_agent_scd_serialno (ctrl_t ctrl, char **r_serialno)
 589 {
 590   int rc;
 591   char *serialno = NULL;
 592
 593   *r_serialno = NULL;
 594   rc = start_agent (ctrl);
 595   if (rc)
 596     return rc;
 597
 598   rc = assuan_transact (agent_ctx, "SCD SERIALNO",
 599                         NULL, NULL,
 600                         default_inq_cb, ctrl,
 601                         scd_serialno_status_cb, &serialno);
 602   if (!rc && !serialno)
 603     rc = gpg_error (GPG_ERR_INTERNAL);
 604   if (rc)
 605     {
 606       xfree (serialno);
 607       return rc;
 608     }
 609   *r_serialno = serialno;
 610   return 0;
 611 }
 612
 613
 614 \f
 615 /* Callback for the gpgsm_agent_serialno fucntion.  */
 616 static gpg_error_t
 617 scd_keypairinfo_status_cb (void *opaque, const char *line)
 618 {
 619   strlist_t *listaddr = opaque;
 620   const char *keyword = line;
 621   int keywordlen;
 622   strlist_t sl;
 623   char *p;
 624
 625   for (keywordlen=0; *line && !spacep (line); line++, keywordlen++)
 626     ;
 627   while (spacep (line))
 628     line++;
 629
 630   if (keywordlen == 11 && !memcmp (keyword, "KEYPAIRINFO", keywordlen))
 631     {
 632       sl = append_to_strlist (listaddr, line);
 633       p = sl->d;
 634       /* Make sure that we only have two tokes so that future
 635          extensions of the format won't change the format expected by
 636          the caller.  */
 637       while (*p && !spacep (p))
 638         p++;
 639       if (*p)
 640         {
 641           while (spacep (p))
 642             p++;
 643           while (*p && !spacep (p))
 644             p++;
 645           *p = 0;
 646         }
 647     }
 648
 649   return 0;
 650 }
 651
 652
 653 /* Call the agent to read the keypairinfo lines of the current card.
 654    The list is returned as a string made up of the keygrip, a space
 655    and the keyid.  */
 656 int
 657 gpgsm_agent_scd_keypairinfo (ctrl_t ctrl, strlist_t *r_list)
 658 {
 659   int rc;
 660   strlist_t list = NULL;
 661
 662   *r_list = NULL;
 663   rc = start_agent (ctrl);
 664   if (rc)
 665     return rc;
 666
 667   rc = assuan_transact (agent_ctx, "SCD LEARN --force",
 668                         NULL, NULL,
 669                         default_inq_cb, ctrl,
 670                         scd_keypairinfo_status_cb, &list);
 671   if (!rc && !list)
 672     rc = gpg_error (GPG_ERR_NO_DATA);
 673   if (rc)
 674     {
 675       free_strlist (list);
 676       return rc;
 677     }
 678   *r_list = list;
 679   return 0;
 680 }
 681
 682
 683 \f
 684 static gpg_error_t
 685 istrusted_status_cb (void *opaque, const char *line)
 686 {
 687   struct rootca_flags_s *flags = opaque;
 688
 689   if (!strncmp (line, "TRUSTLISTFLAG", 13) && (line[13]==' ' || !line[13]))
 690     {
 691       for (line += 13; *line == ' '; line++)
 692         ;
 693       if (!strncmp (line, "relax", 5) && (line[5] == ' ' || !line[5]))
 694         flags->relax = 1;
 695       else if (!strncmp (line, "cm", 2) && (line[2] == ' ' || !line[2]))
 696         flags->chain_model = 1;
 697     }
 698   return 0;
 699 }
 700
 701
 702
 703 /* Ask the agent whether the certificate is in the list of trusted
 704    keys.  The certificate is either specified by the CERT object or by
 705    the fingerprint HEXFPR.  ROOTCA_FLAGS is guaranteed to be cleared
 706    on error. */
 707 int
 708 gpgsm_agent_istrusted (ctrl_t ctrl, ksba_cert_t cert, const char *hexfpr,
 709                        struct rootca_flags_s *rootca_flags)
 710 {
 711   int rc;
 712   char line[ASSUAN_LINELENGTH];
 713
 714   memset (rootca_flags, 0, sizeof *rootca_flags);
 715
 716   if (cert && hexfpr)
 717     return gpg_error (GPG_ERR_INV_ARG);
 718
 719   rc = start_agent (ctrl);
 720   if (rc)
 721     return rc;
 722
 723   if (hexfpr)
 724     {
 725       snprintf (line, DIM(line)-1, "ISTRUSTED %s", hexfpr);
 726       line[DIM(line)-1] = 0;
 727     }
 728   else
 729     {
 730       char *fpr;
 731
 732       fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
 733       if (!fpr)
 734         {
 735           log_error ("error getting the fingerprint\n");
 736           return gpg_error (GPG_ERR_GENERAL);
 737         }
 738
 739       snprintf (line, DIM(line)-1, "ISTRUSTED %s", fpr);
 740       line[DIM(line)-1] = 0;
 741       xfree (fpr);
 742     }
 743
 744   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL,
 745                         istrusted_status_cb, rootca_flags);
 746   if (!rc)
 747     rootca_flags->valid = 1;
 748   return rc;
 749 }
 750
 751 /* Ask the agent to mark CERT as a trusted Root-CA one */
 752 int
 753 gpgsm_agent_marktrusted (ctrl_t ctrl, ksba_cert_t cert)
 754 {
 755   int rc;
 756   char *fpr, *dn, *dnfmt;
 757   char line[ASSUAN_LINELENGTH];
 758
 759   rc = start_agent (ctrl);
 760   if (rc)
 761     return rc;
 762
 763   fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
 764   if (!fpr)
 765     {
 766       log_error ("error getting the fingerprint\n");
 767       return gpg_error (GPG_ERR_GENERAL);
 768     }
 769
 770   dn = ksba_cert_get_issuer (cert, 0);
 771   if (!dn)
 772     {
 773       xfree (fpr);
 774       return gpg_error (GPG_ERR_GENERAL);
 775     }
 776   dnfmt = gpgsm_format_name2 (dn, 0);
 777   xfree (dn);
 778   if (!dnfmt)
 779     return gpg_error_from_syserror ();
 780   snprintf (line, DIM(line)-1, "MARKTRUSTED %s S %s", fpr, dnfmt);
 781   line[DIM(line)-1] = 0;
 782   ksba_free (dnfmt);
 783   xfree (fpr);
 784
 785   rc = assuan_transact (agent_ctx, line, NULL, NULL,
 786                         default_inq_cb, ctrl, NULL, NULL);
 787   return rc;
 788 }
 789
 790
 791 \f
 792 /* Ask the agent whether the a corresponding secret key is available
 793    for the given keygrip */
 794 int
 795 gpgsm_agent_havekey (ctrl_t ctrl, const char *hexkeygrip)
 796 {
 797   int rc;
 798   char line[ASSUAN_LINELENGTH];
 799
 800   rc = start_agent (ctrl);
 801   if (rc)
 802     return rc;
 803
 804   if (!hexkeygrip || strlen (hexkeygrip) != 40)
 805     return gpg_error (GPG_ERR_INV_VALUE);
 806
 807   snprintf (line, DIM(line)-1, "HAVEKEY %s", hexkeygrip);
 808   line[DIM(line)-1] = 0;
 809
 810   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 811   return rc;
 812 }
 813
 814 \f
 815 static gpg_error_t
 816 learn_status_cb (void *opaque, const char *line)
 817 {
 818   struct learn_parm_s *parm = opaque;
 819
 820   /* Pass progress data to the caller.  */
 821   if (!strncmp (line, "PROGRESS", 8) && (line[8]==' ' || !line[8]))
 822     {
 823       if (parm->ctrl)
 824         {
 825           for (line += 8; *line == ' '; line++)
 826             ;
 827           if (gpgsm_status (parm->ctrl, STATUS_PROGRESS, line))
 828             return gpg_error (GPG_ERR_ASS_CANCELED);
 829         }
 830     }
 831   return 0;
 832 }
 833
 834 static gpg_error_t
 835 learn_cb (void *opaque, const void *buffer, size_t length)
 836 {
 837   struct learn_parm_s *parm = opaque;
 838   size_t len;
 839   char *buf;
 840   ksba_cert_t cert;
 841   int rc;
 842
 843   if (parm->error)
 844     return 0;
 845
 846   if (buffer)
 847     {
 848       put_membuf (parm->data, buffer, length);
 849       return 0;
 850     }
 851   /* END encountered - process what we have */
 852   buf = get_membuf (parm->data, &len);
 853   if (!buf)
 854     {
 855       parm->error = gpg_error (GPG_ERR_ENOMEM);
 856       return 0;
 857     }
 858
 859   if (gpgsm_status (parm->ctrl, STATUS_PROGRESS, "learncard C 0 0"))
 860     return gpg_error (GPG_ERR_ASS_CANCELED);
 861
 862   /* FIXME: this should go into import.c */
 863   rc = ksba_cert_new (&cert);
 864   if (rc)
 865     {
 866       parm->error = rc;
 867       return 0;
 868     }
 869   rc = ksba_cert_init_from_mem (cert, buf, len);
 870   if (rc)
 871     {
 872       log_error ("failed to parse a certificate: %s\n", gpg_strerror (rc));
 873       ksba_cert_release (cert);
 874       parm->error = rc;
 875       return 0;
 876     }
 877
 878   /* We do not store a certifciate with missing issuers as ephemeral
 879      because we can assume that the --learn-card command has been used
 880      on purpose.  */
 881   rc = gpgsm_basic_cert_check (parm->ctrl, cert);
 882   if (rc && gpg_err_code (rc) != GPG_ERR_MISSING_CERT)
 883     log_error ("invalid certificate: %s\n", gpg_strerror (rc));
 884   else
 885     {
 886       int existed;
 887
 888       if (!keydb_store_cert (cert, 0, &existed))
 889         {
 890           if (opt.verbose > 1 && existed)
 891             log_info ("certificate already in DB\n");
 892           else if (opt.verbose && !existed)
 893             log_info ("certificate imported\n");
 894         }
 895     }
 896
 897   ksba_cert_release (cert);
 898   init_membuf (parm->data, 4096);
 899   return 0;
 900 }
 901
 902 /* Call the agent to learn about a smartcard */
 903 int
 904 gpgsm_agent_learn (ctrl_t ctrl)
 905 {
 906   int rc;
 907   struct learn_parm_s learn_parm;
 908   membuf_t data;
 909   size_t len;
 910
 911   rc = start_agent (ctrl);
 912   if (rc)
 913     return rc;
 914
 915   init_membuf (&data, 4096);
 916   learn_parm.error = 0;
 917   learn_parm.ctrl = ctrl;
 918   learn_parm.ctx = agent_ctx;
 919   learn_parm.data = &data;
 920   rc = assuan_transact (agent_ctx, "LEARN --send",
 921                         learn_cb, &learn_parm,
 922                         NULL, NULL,
 923                         learn_status_cb, &learn_parm);
 924   xfree (get_membuf (&data, &len));
 925   if (rc)
 926     return rc;
 927   return learn_parm.error;
 928 }
 929
 930 \f
 931 /* Ask the agent to change the passphrase of the key identified by
 932    HEXKEYGRIP. If DESC is not NULL, display instead of the default
 933    description message. */
 934 int
 935 gpgsm_agent_passwd (ctrl_t ctrl, const char *hexkeygrip, const char *desc)
 936 {
 937   int rc;
 938   char line[ASSUAN_LINELENGTH];
 939
 940   rc = start_agent (ctrl);
 941   if (rc)
 942     return rc;
 943
 944   if (!hexkeygrip || strlen (hexkeygrip) != 40)
 945     return gpg_error (GPG_ERR_INV_VALUE);
 946
 947   if (desc)
 948     {
 949       snprintf (line, DIM(line)-1, "SETKEYDESC %s", desc);
 950       line[DIM(line)-1] = 0;
 951       rc = assuan_transact (agent_ctx, line,
 952                             NULL, NULL, NULL, NULL, NULL, NULL);
 953       if (rc)
 954         return rc;
 955     }
 956
 957   snprintf (line, DIM(line)-1, "PASSWD %s", hexkeygrip);
 958   line[DIM(line)-1] = 0;
 959
 960   rc = assuan_transact (agent_ctx, line, NULL, NULL,
 961                         default_inq_cb, ctrl, NULL, NULL);
 962   return rc;
 963 }
 964
 965
 966 \f
 967 /* Ask the agent to pop up a confirmation dialog with the text DESC
 968    and an okay and cancel button.  */
 969 gpg_error_t
 970 gpgsm_agent_get_confirmation (ctrl_t ctrl, const char *desc)
 971 {
 972   int rc;
 973   char line[ASSUAN_LINELENGTH];
 974
 975   rc = start_agent (ctrl);
 976   if (rc)
 977     return rc;
 978
 979   snprintf (line, DIM(line)-1, "GET_CONFIRMATION %s", desc);
 980   line[DIM(line)-1] = 0;
 981
 982   rc = assuan_transact (agent_ctx, line, NULL, NULL,
 983                         default_inq_cb, ctrl, NULL, NULL);
 984   return rc;
 985 }
 986
 987
 988 \f
 989 /* Return 0 if the agent is alive.  This is useful to make sure that
 990    an agent has been started. */
 991 gpg_error_t
 992 gpgsm_agent_send_nop (ctrl_t ctrl)
 993 {
 994   int rc;
 995
 996   rc = start_agent (ctrl);
 997   if (!rc)
 998     rc = assuan_transact (agent_ctx, "NOP",
 999                           NULL, NULL, NULL, NULL, NULL, NULL);
1000   return rc;
1001 }
1002
1003
1004 \f
1005 static gpg_error_t
1006 keyinfo_status_cb (void *opaque, const char *line)
1007 {
1008   char **serialno = opaque;
1009   const char *s, *s2;
1010
1011   if (!strncmp (line, "KEYINFO ", 8) && !*serialno)
1012     {
1013       s = strchr (line+8, ' ');
1014       if (s && s[1] == 'T' && s[2] == ' ' && s[3])
1015         {
1016           s += 3;
1017           s2 = strchr (s, ' ');
1018           if ( s2 > s )
1019             {
1020               *serialno = xtrymalloc ((s2 - s)+1);
1021               if (*serialno)
1022                 {
1023                   memcpy (*serialno, s, s2 - s);
1024                   (*serialno)[s2 - s] = 0;
1025                 }
1026             }
1027         }
1028     }
1029   return 0;
1030 }
1031
1032 /* Return the serial number for a secret key.  If the returned serial
1033    number is NULL, the key is not stored on a smartcard.  Caller needs
1034    to free R_SERIALNO.  */
1035 gpg_error_t
1036 gpgsm_agent_keyinfo (ctrl_t ctrl, const char *hexkeygrip, char **r_serialno)
1037 {
1038   gpg_error_t err;
1039   char line[ASSUAN_LINELENGTH];
1040   char *serialno = NULL;
1041
1042   *r_serialno = NULL;
1043
1044   err = start_agent (ctrl);
1045   if (err)
1046     return err;
1047
1048   if (!hexkeygrip || strlen (hexkeygrip) != 40)
1049     return gpg_error (GPG_ERR_INV_VALUE);
1050
1051   snprintf (line, DIM(line)-1, "KEYINFO %s", hexkeygrip);
1052   line[DIM(line)-1] = 0;
1053
1054   err = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL,
1055                          keyinfo_status_cb, &serialno);
1056   if (!err && serialno)
1057     {
1058       /* Sanity check for bad characters.  */
1059       if (strpbrk (serialno, ":\n\r"))
1060         err = GPG_ERR_INV_VALUE;
1061     }
1062   if (err)
1063     xfree (serialno);
1064   else
1065     *r_serialno = serialno;
1066   return err;
1067 }
1068