sm/call-agent.c

   1 /* call-agent.c - divert operations to the agent
   2  *      Copyright (C) 2001, 2002, 2003, 2005 Free Software Foundation, Inc.
   3  *
   4  * This file is part of GnuPG.
   5  *
   6  * GnuPG is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GnuPG is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19  * USA.
  20  */
  21
  22 #include <config.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <errno.h>
  27 #include <unistd.h>
  28 #include <time.h>
  29 #include <assert.h>
  30 #ifdef HAVE_LOCALE_H
  31 #include <locale.h>
  32 #endif
  33
  34 #include "gpgsm.h"
  35 #include <gcrypt.h>
  36 #include <assuan.h>
  37 #include "i18n.h"
  38 #include "asshelp.h"
  39 #include "keydb.h" /* fixme: Move this to import.c */
  40 #include "../common/membuf.h"
  41
  42
  43 static assuan_context_t agent_ctx = NULL;
  44 static int force_pipe_server = 0;
  45
  46 struct cipher_parm_s
  47 {
  48   assuan_context_t ctx;
  49   const unsigned char *ciphertext;
  50   size_t ciphertextlen;
  51 };
  52
  53 struct genkey_parm_s
  54 {
  55   assuan_context_t ctx;
  56   const unsigned char *sexp;
  57   size_t sexplen;
  58 };
  59
  60 struct learn_parm_s
  61 {
  62   int error;
  63   assuan_context_t ctx;
  64   membuf_t *data;
  65 };
  66
  67
  68 \f
  69 /* Try to connect to the agent via socket or fork it off and work by
  70    pipes.  Handle the server's initial greeting */
  71 static int
  72 start_agent (ctrl_t ctrl)
  73 {
  74   int rc = 0;
  75   char *infostr, *p;
  76   assuan_context_t ctx;
  77
  78   if (agent_ctx)
  79     return 0; /* fixme: We need a context for each thread or serialize
  80                  the access to the agent (which is suitable given that
  81                  the agent is not MT. */
  82
  83   infostr = force_pipe_server? NULL : getenv ("GPG_AGENT_INFO");
  84   if (!infostr || !*infostr)
  85     {
  86       const char *pgmname;
  87       const char *argv[3];
  88       char *sockname;
  89       int no_close_list[3];
  90       int i;
  91
  92       /* First check whether we can connect at the standard
  93          socket.  */
  94       sockname = make_filename (opt.homedir, "S.gpg-agent", NULL);
  95       rc = assuan_socket_connect (&ctx, sockname, 0);
  96       xfree (sockname);
  97
  98       if (rc)
  99         {
 100           /* With no success start a new server.  */
 101           if (opt.verbose)
 102             log_info (_("no running gpg-agent - starting one\n"));
 103
 104           gpgsm_status (ctrl, STATUS_PROGRESS, "starting_agent ? 0 0");
 105
 106           if (fflush (NULL))
 107             {
 108               gpg_error_t tmperr = gpg_error (gpg_err_code_from_errno (errno));
 109               log_error ("error flushing pending output: %s\n",
 110                          strerror (errno));
 111               return tmperr;
 112             }
 113
 114           if (!opt.agent_program || !*opt.agent_program)
 115             opt.agent_program = GNUPG_DEFAULT_AGENT;
 116           if ( !(pgmname = strrchr (opt.agent_program, '/')))
 117             pgmname = opt.agent_program;
 118           else
 119             pgmname++;
 120
 121           argv[0] = pgmname;
 122           argv[1] = "--server";
 123           argv[2] = NULL;
 124
 125           i=0;
 126           if (log_get_fd () != -1)
 127             no_close_list[i++] = log_get_fd ();
 128           no_close_list[i++] = fileno (stderr);
 129           no_close_list[i] = -1;
 130
 131           /* Connect to the agent and perform initial handshaking. */
 132           rc = assuan_pipe_connect (&ctx, opt.agent_program, argv,
 133                                     no_close_list);
 134         }
 135     }
 136   else
 137     {
 138       int prot;
 139       int pid;
 140
 141       infostr = xstrdup (infostr);
 142       if ( !(p = strchr (infostr, PATHSEP_C)) || p == infostr)
 143         {
 144           log_error (_("malformed GPG_AGENT_INFO environment variable\n"));
 145           xfree (infostr);
 146           force_pipe_server = 1;
 147           return start_agent (ctrl);
 148         }
 149       *p++ = 0;
 150       pid = atoi (p);
 151       while (*p && *p != PATHSEP_C)
 152         p++;
 153       prot = *p? atoi (p+1) : 0;
 154       if (prot != 1)
 155         {
 156           log_error (_("gpg-agent protocol version %d is not supported\n"),
 157                      prot);
 158           xfree (infostr);
 159           force_pipe_server = 1;
 160           return start_agent (ctrl);
 161         }
 162
 163       rc = assuan_socket_connect (&ctx, infostr, pid);
 164       xfree (infostr);
 165       if (gpg_err_code (rc) == GPG_ERR_ASS_CONNECT_FAILED)
 166         {
 167           log_error (_("can't connect to the agent - trying fall back\n"));
 168           force_pipe_server = 1;
 169           return start_agent (ctrl);
 170         }
 171     }
 172
 173   if (rc)
 174     {
 175       log_error ("can't connect to the agent: %s\n", gpg_strerror (rc));
 176       return gpg_error (GPG_ERR_NO_AGENT);
 177     }
 178   agent_ctx = ctx;
 179
 180   if (DBG_ASSUAN)
 181     log_debug ("connection to agent established\n");
 182
 183   rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
 184   if (rc)
 185     return rc;
 186
 187   return send_pinentry_environment (agent_ctx, GPG_ERR_SOURCE_DEFAULT,
 188                                     opt.display, opt.ttyname, opt.ttytype,
 189                                     opt.lc_ctype, opt.lc_messages);
 190 }
 191
 192
 193 static int
 194 membuf_data_cb (void *opaque, const void *buffer, size_t length)
 195 {
 196   membuf_t *data = opaque;
 197
 198   if (buffer)
 199     put_membuf (data, buffer, length);
 200   return 0;
 201 }
 202
 203
 204
 205 \f
 206 /* Call the agent to do a sign operation using the key identified by
 207    the hex string KEYGRIP. */
 208 int
 209 gpgsm_agent_pksign (ctrl_t ctrl, const char *keygrip, const char *desc,
 210                     unsigned char *digest, size_t digestlen, int digestalgo,
 211                     unsigned char **r_buf, size_t *r_buflen )
 212 {
 213   int rc, i;
 214   char *p, line[ASSUAN_LINELENGTH];
 215   membuf_t data;
 216   size_t len;
 217
 218   *r_buf = NULL;
 219   rc = start_agent (ctrl);
 220   if (rc)
 221     return rc;
 222
 223   if (digestlen*2 + 50 > DIM(line))
 224     return gpg_error (GPG_ERR_GENERAL);
 225
 226   rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
 227   if (rc)
 228     return rc;
 229
 230   snprintf (line, DIM(line)-1, "SIGKEY %s", keygrip);
 231   line[DIM(line)-1] = 0;
 232   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 233   if (rc)
 234     return rc;
 235
 236   if (desc)
 237     {
 238       snprintf (line, DIM(line)-1, "SETKEYDESC %s", desc);
 239       line[DIM(line)-1] = 0;
 240       rc = assuan_transact (agent_ctx, line,
 241                             NULL, NULL, NULL, NULL, NULL, NULL);
 242       if (rc)
 243         return rc;
 244     }
 245
 246   sprintf (line, "SETHASH %d ", digestalgo);
 247   p = line + strlen (line);
 248   for (i=0; i < digestlen ; i++, p += 2 )
 249     sprintf (p, "%02X", digest[i]);
 250   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 251   if (rc)
 252     return rc;
 253
 254   init_membuf (&data, 1024);
 255   rc = assuan_transact (agent_ctx, "PKSIGN",
 256                         membuf_data_cb, &data, NULL, NULL, NULL, NULL);
 257   if (rc)
 258     {
 259       xfree (get_membuf (&data, &len));
 260       return rc;
 261     }
 262   *r_buf = get_membuf (&data, r_buflen);
 263
 264   if (!gcry_sexp_canon_len (*r_buf, *r_buflen, NULL, NULL))
 265     {
 266       xfree (*r_buf); *r_buf = NULL;
 267       return gpg_error (GPG_ERR_INV_VALUE);
 268     }
 269
 270   return *r_buf? 0 : out_of_core ();
 271 }
 272
 273
 274 /* Call the scdaemon to do a sign operation using the key identified by
 275    the hex string KEYID. */
 276 int
 277 gpgsm_scd_pksign (ctrl_t ctrl, const char *keyid, const char *desc,
 278                   unsigned char *digest, size_t digestlen, int digestalgo,
 279                   unsigned char **r_buf, size_t *r_buflen )
 280 {
 281   int rc, i;
 282   char *p, line[ASSUAN_LINELENGTH];
 283   membuf_t data;
 284   size_t len;
 285   const char *hashopt;
 286   unsigned char *sigbuf;
 287   size_t sigbuflen;
 288
 289   *r_buf = NULL;
 290
 291   switch(digestalgo)
 292     {
 293     case GCRY_MD_SHA1:  hashopt = "--hash=sha1"; break;
 294     case GCRY_MD_RMD160:hashopt = "--hash=rmd160"; break;
 295     case GCRY_MD_MD5:   hashopt = "--hash=md5"; break;
 296     case GCRY_MD_SHA256:hashopt = "--hash=sha256"; break;
 297     default:
 298       return gpg_error (GPG_ERR_DIGEST_ALGO);
 299     }
 300
 301   rc = start_agent (ctrl);
 302   if (rc)
 303     return rc;
 304
 305   if (digestlen*2 + 50 > DIM(line))
 306     return gpg_error (GPG_ERR_GENERAL);
 307
 308   p = stpcpy (line, "SCD SETDATA " );
 309   for (i=0; i < digestlen ; i++, p += 2 )
 310     sprintf (p, "%02X", digest[i]);
 311   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 312   if (rc)
 313     return rc;
 314
 315   init_membuf (&data, 1024);
 316
 317   snprintf (line, DIM(line)-1, "SCD PKSIGN %s %s", hashopt, keyid);
 318   line[DIM(line)-1] = 0;
 319   rc = assuan_transact (agent_ctx, line,
 320                         membuf_data_cb, &data, NULL, NULL, NULL, NULL);
 321   if (rc)
 322     {
 323       xfree (get_membuf (&data, &len));
 324       return rc;
 325     }
 326   sigbuf = get_membuf (&data, &sigbuflen);
 327
 328   /* Create an S-expression from it which is formatted like this:
 329      "(7:sig-val(3:rsa(1:sSIGBUFLEN:SIGBUF)))" Fixme: If a card ever
 330      creates non-RSA keys we need to change things. */
 331   *r_buflen = 21 + 11 + sigbuflen + 4;
 332   p = xtrymalloc (*r_buflen);
 333   *r_buf = (unsigned char*)p;
 334   if (!p)
 335     {
 336       xfree (sigbuf);
 337       return 0;
 338     }
 339   p = stpcpy (p, "(7:sig-val(3:rsa(1:s" );
 340   sprintf (p, "%u:", (unsigned int)sigbuflen);
 341   p += strlen (p);
 342   memcpy (p, sigbuf, sigbuflen);
 343   p += sigbuflen;
 344   strcpy (p, ")))");
 345   xfree (sigbuf);
 346
 347   assert (gcry_sexp_canon_len (*r_buf, *r_buflen, NULL, NULL));
 348   return  0;
 349 }
 350
 351
 352
 353 \f
 354 /* Handle a CIPHERTEXT inquiry.  Note, we only send the data,
 355    assuan_transact talkes care of flushing and writing the end */
 356 static int
 357 inq_ciphertext_cb (void *opaque, const char *keyword)
 358 {
 359   struct cipher_parm_s *parm = opaque;
 360   int rc;
 361
 362   assuan_begin_confidential (parm->ctx);
 363   rc = assuan_send_data (parm->ctx, parm->ciphertext, parm->ciphertextlen);
 364   assuan_end_confidential (parm->ctx);
 365   return rc;
 366 }
 367
 368
 369 /* Call the agent to do a decrypt operation using the key identified by
 370    the hex string KEYGRIP. */
 371 int
 372 gpgsm_agent_pkdecrypt (ctrl_t ctrl, const char *keygrip, const char *desc,
 373                        ksba_const_sexp_t ciphertext,
 374                        char **r_buf, size_t *r_buflen )
 375 {
 376   int rc;
 377   char line[ASSUAN_LINELENGTH];
 378   membuf_t data;
 379   struct cipher_parm_s cipher_parm;
 380   size_t n, len;
 381   char *p, *buf, *endp;
 382   size_t ciphertextlen;
 383
 384   if (!keygrip || strlen(keygrip) != 40 || !ciphertext || !r_buf || !r_buflen)
 385     return gpg_error (GPG_ERR_INV_VALUE);
 386   *r_buf = NULL;
 387
 388   ciphertextlen = gcry_sexp_canon_len (ciphertext, 0, NULL, NULL);
 389   if (!ciphertextlen)
 390     return gpg_error (GPG_ERR_INV_VALUE);
 391
 392   rc = start_agent (ctrl);
 393   if (rc)
 394     return rc;
 395
 396   rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
 397   if (rc)
 398     return rc;
 399
 400   assert ( DIM(line) >= 50 );
 401   snprintf (line, DIM(line)-1, "SETKEY %s", keygrip);
 402   line[DIM(line)-1] = 0;
 403   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 404   if (rc)
 405     return rc;
 406
 407   if (desc)
 408     {
 409       snprintf (line, DIM(line)-1, "SETKEYDESC %s", desc);
 410       line[DIM(line)-1] = 0;
 411       rc = assuan_transact (agent_ctx, line,
 412                             NULL, NULL, NULL, NULL, NULL, NULL);
 413       if (rc)
 414         return rc;
 415     }
 416
 417   init_membuf (&data, 1024);
 418   cipher_parm.ctx = agent_ctx;
 419   cipher_parm.ciphertext = ciphertext;
 420   cipher_parm.ciphertextlen = ciphertextlen;
 421   rc = assuan_transact (agent_ctx, "PKDECRYPT",
 422                         membuf_data_cb, &data,
 423                         inq_ciphertext_cb, &cipher_parm, NULL, NULL);
 424   if (rc)
 425     {
 426       xfree (get_membuf (&data, &len));
 427       return rc;
 428     }
 429
 430   put_membuf (&data, "", 1); /* Make sure it is 0 terminated. */
 431   buf = get_membuf (&data, &len);
 432   if (!buf)
 433     return gpg_error (GPG_ERR_ENOMEM);
 434   assert (len); /* (we forced Nul termination.)  */
 435
 436   if (*buf == '(')
 437     {
 438       if (len < 13 || memcmp (buf, "(5:value", 8) ) /* "(5:valueN:D)\0" */
 439         return gpg_error (GPG_ERR_INV_SEXP);
 440       len -= 11;   /* Count only the data of the second part. */
 441       p = buf + 8; /* Skip leading parenthesis and the value tag. */
 442     }
 443   else
 444     {
 445       /* For compatibility with older gpg-agents handle the old style
 446          incomplete S-exps. */
 447       len--;      /* Do not count the Nul. */
 448       p = buf;
 449     }
 450
 451   n = strtoul (p, &endp, 10);
 452   if (!n || *endp != ':')
 453     return gpg_error (GPG_ERR_INV_SEXP);
 454   endp++;
 455   if (endp-p+n > len)
 456     return gpg_error (GPG_ERR_INV_SEXP); /* Oops: Inconsistent S-Exp. */
 457
 458   memmove (buf, endp, n);
 459
 460   *r_buflen = n;
 461   *r_buf = buf;
 462   return 0;
 463 }
 464
 465
 466
 467
 468 \f
 469 /* Handle a KEYPARMS inquiry.  Note, we only send the data,
 470    assuan_transact takes care of flushing and writing the end */
 471 static int
 472 inq_genkey_parms (void *opaque, const char *keyword)
 473 {
 474   struct genkey_parm_s *parm = opaque;
 475   int rc;
 476
 477   rc = assuan_send_data (parm->ctx, parm->sexp, parm->sexplen);
 478   return rc;
 479 }
 480
 481
 482 \f
 483 /* Call the agent to generate a newkey */
 484 int
 485 gpgsm_agent_genkey (ctrl_t ctrl,
 486                     ksba_const_sexp_t keyparms, ksba_sexp_t *r_pubkey)
 487 {
 488   int rc;
 489   struct genkey_parm_s gk_parm;
 490   membuf_t data;
 491   size_t len;
 492   unsigned char *buf;
 493
 494   *r_pubkey = NULL;
 495   rc = start_agent (ctrl);
 496   if (rc)
 497     return rc;
 498
 499   rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
 500   if (rc)
 501     return rc;
 502
 503   init_membuf (&data, 1024);
 504   gk_parm.ctx = agent_ctx;
 505   gk_parm.sexp = keyparms;
 506   gk_parm.sexplen = gcry_sexp_canon_len (keyparms, 0, NULL, NULL);
 507   if (!gk_parm.sexplen)
 508     return gpg_error (GPG_ERR_INV_VALUE);
 509   rc = assuan_transact (agent_ctx, "GENKEY",
 510                         membuf_data_cb, &data,
 511                         inq_genkey_parms, &gk_parm, NULL, NULL);
 512   if (rc)
 513     {
 514       xfree (get_membuf (&data, &len));
 515       return rc;
 516     }
 517   buf = get_membuf (&data, &len);
 518   if (!buf)
 519     return gpg_error (GPG_ERR_ENOMEM);
 520   if (!gcry_sexp_canon_len (buf, len, NULL, NULL))
 521     {
 522       xfree (buf);
 523       return gpg_error (GPG_ERR_INV_SEXP);
 524     }
 525   *r_pubkey = buf;
 526   return 0;
 527 }
 528
 529 \f
 530 /* Call the agent to read the public key part for a given keygrip.  If
 531    FROMCARD is true, the key is directly read from the current
 532    smartcard. In this case HEXKEYGRIP should be the keyID
 533    (e.g. OPENPGP.3). */
 534 int
 535 gpgsm_agent_readkey (ctrl_t ctrl, int fromcard, const char *hexkeygrip,
 536                      ksba_sexp_t *r_pubkey)
 537 {
 538   int rc;
 539   membuf_t data;
 540   size_t len;
 541   unsigned char *buf;
 542   char line[ASSUAN_LINELENGTH];
 543
 544   *r_pubkey = NULL;
 545   rc = start_agent (ctrl);
 546   if (rc)
 547     return rc;
 548
 549   rc = assuan_transact (agent_ctx, "RESET",NULL, NULL, NULL, NULL, NULL, NULL);
 550   if (rc)
 551     return rc;
 552
 553   snprintf (line, DIM(line)-1, "%sREADKEY %s",
 554             fromcard? "SCD ":"", hexkeygrip);
 555   line[DIM(line)-1] = 0;
 556
 557   init_membuf (&data, 1024);
 558   rc = assuan_transact (agent_ctx, line,
 559                         membuf_data_cb, &data,
 560                         NULL, NULL, NULL, NULL);
 561   if (rc)
 562     {
 563       xfree (get_membuf (&data, &len));
 564       return rc;
 565     }
 566   buf = get_membuf (&data, &len);
 567   if (!buf)
 568     return gpg_error (GPG_ERR_ENOMEM);
 569   if (!gcry_sexp_canon_len (buf, len, NULL, NULL))
 570     {
 571       xfree (buf);
 572       return gpg_error (GPG_ERR_INV_SEXP);
 573     }
 574   *r_pubkey = buf;
 575   return 0;
 576 }
 577
 578 \f
 579
 580 static int
 581 istrusted_status_cb (void *opaque, const char *line)
 582 {
 583   struct rootca_flags_s *flags = opaque;
 584
 585   if (!strncmp (line, "TRUSTLISTFLAG", 13) && (line[13]==' ' || !line[13]))
 586     {
 587       for (line += 13; *line == ' '; line++)
 588         ;
 589       if (!strncmp (line, "relax", 5) && (line[5] == ' ' || !line[5]))
 590         flags->relax = 1;
 591     }
 592   return 0;
 593 }
 594
 595
 596
 597 /* Ask the agent whether the certificate is in the list of trusted
 598    keys.  ROOTCA_FLAGS is guaranteed to be cleared on error. */
 599 int
 600 gpgsm_agent_istrusted (ctrl_t ctrl, ksba_cert_t cert,
 601                        struct rootca_flags_s *rootca_flags)
 602 {
 603   int rc;
 604   char *fpr;
 605   char line[ASSUAN_LINELENGTH];
 606
 607   memset (rootca_flags, 0, sizeof *rootca_flags);
 608
 609   rc = start_agent (ctrl);
 610   if (rc)
 611     return rc;
 612
 613   fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
 614   if (!fpr)
 615     {
 616       log_error ("error getting the fingerprint\n");
 617       return gpg_error (GPG_ERR_GENERAL);
 618     }
 619
 620   snprintf (line, DIM(line)-1, "ISTRUSTED %s", fpr);
 621   line[DIM(line)-1] = 0;
 622   xfree (fpr);
 623
 624   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL,
 625                         istrusted_status_cb, rootca_flags);
 626   return rc;
 627 }
 628
 629 /* Ask the agent to mark CERT as a trusted Root-CA one */
 630 int
 631 gpgsm_agent_marktrusted (ctrl_t ctrl, ksba_cert_t cert)
 632 {
 633   int rc;
 634   char *fpr, *dn;
 635   char line[ASSUAN_LINELENGTH];
 636
 637   rc = start_agent (ctrl);
 638   if (rc)
 639     return rc;
 640
 641   fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
 642   if (!fpr)
 643     {
 644       log_error ("error getting the fingerprint\n");
 645       return gpg_error (GPG_ERR_GENERAL);
 646     }
 647
 648   dn = ksba_cert_get_issuer (cert, 0);
 649   if (!dn)
 650     {
 651       xfree (fpr);
 652       return gpg_error (GPG_ERR_GENERAL);
 653     }
 654   snprintf (line, DIM(line)-1, "MARKTRUSTED %s S %s", fpr, dn);
 655   line[DIM(line)-1] = 0;
 656   ksba_free (dn);
 657   xfree (fpr);
 658
 659   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 660   return rc;
 661 }
 662
 663
 664 \f
 665 /* Ask the agent whether the a corresponding secret key is available
 666    for the given keygrip */
 667 int
 668 gpgsm_agent_havekey (ctrl_t ctrl, const char *hexkeygrip)
 669 {
 670   int rc;
 671   char line[ASSUAN_LINELENGTH];
 672
 673   rc = start_agent (ctrl);
 674   if (rc)
 675     return rc;
 676
 677   if (!hexkeygrip || strlen (hexkeygrip) != 40)
 678     return gpg_error (GPG_ERR_INV_VALUE);
 679
 680   snprintf (line, DIM(line)-1, "HAVEKEY %s", hexkeygrip);
 681   line[DIM(line)-1] = 0;
 682
 683   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 684   return rc;
 685 }
 686
 687 \f
 688 static int
 689 learn_cb (void *opaque, const void *buffer, size_t length)
 690 {
 691   struct learn_parm_s *parm = opaque;
 692   size_t len;
 693   char *buf;
 694   ksba_cert_t cert;
 695   int rc;
 696
 697   if (parm->error)
 698     return 0;
 699
 700   if (buffer)
 701     {
 702       put_membuf (parm->data, buffer, length);
 703       return 0;
 704     }
 705   /* END encountered - process what we have */
 706   buf = get_membuf (parm->data, &len);
 707   if (!buf)
 708     {
 709       parm->error = gpg_error (GPG_ERR_ENOMEM);
 710       return 0;
 711     }
 712
 713
 714   /* FIXME: this should go into import.c */
 715   rc = ksba_cert_new (&cert);
 716   if (rc)
 717     {
 718       parm->error = rc;
 719       return 0;
 720     }
 721   rc = ksba_cert_init_from_mem (cert, buf, len);
 722   if (rc)
 723     {
 724       log_error ("failed to parse a certificate: %s\n", gpg_strerror (rc));
 725       ksba_cert_release (cert);
 726       parm->error = rc;
 727       return 0;
 728     }
 729
 730   rc = gpgsm_basic_cert_check (cert);
 731   if (gpg_err_code (rc) == GPG_ERR_MISSING_CERT)
 732     { /* For later use we store it in the ephemeral database. */
 733       log_info ("issuer certificate missing - storing as ephemeral\n");
 734       keydb_store_cert (cert, 1, NULL);
 735     }
 736   else if (rc)
 737     log_error ("invalid certificate: %s\n", gpg_strerror (rc));
 738   else
 739     {
 740       int existed;
 741
 742       if (!keydb_store_cert (cert, 0, &existed))
 743         {
 744           if (opt.verbose > 1 && existed)
 745             log_info ("certificate already in DB\n");
 746           else if (opt.verbose && !existed)
 747             log_info ("certificate imported\n");
 748         }
 749     }
 750
 751   ksba_cert_release (cert);
 752   init_membuf (parm->data, 4096);
 753   return 0;
 754 }
 755
 756 /* Call the agent to learn about a smartcard */
 757 int
 758 gpgsm_agent_learn (ctrl_t ctrl)
 759 {
 760   int rc;
 761   struct learn_parm_s learn_parm;
 762   membuf_t data;
 763   size_t len;
 764
 765   rc = start_agent (ctrl);
 766   if (rc)
 767     return rc;
 768
 769   init_membuf (&data, 4096);
 770   learn_parm.error = 0;
 771   learn_parm.ctx = agent_ctx;
 772   learn_parm.data = &data;
 773   rc = assuan_transact (agent_ctx, "LEARN --send",
 774                         learn_cb, &learn_parm,
 775                         NULL, NULL, NULL, NULL);
 776   xfree (get_membuf (&data, &len));
 777   if (rc)
 778     return rc;
 779   return learn_parm.error;
 780 }
 781
 782 \f
 783 /* Ask the agent to change the passphrase of the key identified by
 784    HEXKEYGRIP. If DESC is not NULL, display instead of the default
 785    description message. */
 786 int
 787 gpgsm_agent_passwd (ctrl_t ctrl, const char *hexkeygrip, const char *desc)
 788 {
 789   int rc;
 790   char line[ASSUAN_LINELENGTH];
 791
 792   rc = start_agent (ctrl);
 793   if (rc)
 794     return rc;
 795
 796   if (!hexkeygrip || strlen (hexkeygrip) != 40)
 797     return gpg_error (GPG_ERR_INV_VALUE);
 798
 799   if (desc)
 800     {
 801       snprintf (line, DIM(line)-1, "SETKEYDESC %s", desc);
 802       line[DIM(line)-1] = 0;
 803       rc = assuan_transact (agent_ctx, line,
 804                             NULL, NULL, NULL, NULL, NULL, NULL);
 805       if (rc)
 806         return rc;
 807     }
 808
 809   snprintf (line, DIM(line)-1, "PASSWD %s", hexkeygrip);
 810   line[DIM(line)-1] = 0;
 811
 812   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 813   return rc;
 814 }
 815
 816
 817 \f
 818 /* Ask the agent to pop up a confirmation dialog with the text DESC
 819    and an okay and cancel button.  */
 820 gpg_error_t
 821 gpgsm_agent_get_confirmation (ctrl_t ctrl, const char *desc)
 822 {
 823   int rc;
 824   char line[ASSUAN_LINELENGTH];
 825
 826   rc = start_agent (ctrl);
 827   if (rc)
 828     return rc;
 829
 830   snprintf (line, DIM(line)-1, "GET_CONFIRMATION %s", desc);
 831   line[DIM(line)-1] = 0;
 832
 833   rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
 834   return rc;
 835 }