src/agent.c

   1 /*
   2     Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014
   3     Ben Kibbey <bjk@luxsci.net>
   4
   5     This file is part of pwmd.
   6
   7     Pwmd 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 2 of the License, or
  10     (at your option) any later version.
  11
  12     Pwmd 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 Pwmd.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20 #ifdef HAVE_CONFIG_H
  21 #include <config.h>
  22 #endif
  23
  24 #include <stdlib.h>
  25 #include <errno.h>
  26 #include <pwd.h>
  27 #include <sys/types.h>
  28 #include <signal.h>
  29 #include <sys/wait.h>
  30 #include <fcntl.h>
  31 #include <dirent.h>
  32
  33 #ifdef HAVE_LIMITS_H
  34 #include <limits.h>
  35 #endif
  36
  37 #include "pwmd-error.h"
  38 #include "util-misc.h"
  39 #include "mem.h"
  40 #include "common.h"
  41 #include "commands.h"
  42 #include "agent.h"
  43 #include "util-string.h"
  44 #include "mutex.h"
  45 #include "rcfile.h"
  46 #include "cache.h"
  47 #include "cipher.h"
  48 #include "crypto.h"
  49
  50 static gpg_error_t
  51 mem_realloc_cb (void *data, const void *buffer, size_t len)
  52 {
  53   membuf_t *mem = (membuf_t *) data;
  54   void *p;
  55
  56   if (!buffer)
  57     return 0;
  58
  59   if ((p = xrealloc (mem->buf, mem->len + len)) == NULL)
  60     return 1;
  61
  62   mem->buf = p;
  63   memcpy ((char *) mem->buf + mem->len, buffer, len);
  64   mem->len += len;
  65   return 0;
  66 }
  67
  68 /* Forward status messages from gpg-agent to the client. */
  69 static gpg_error_t
  70 status_cb (void *data, const char *line)
  71 {
  72   struct agent_s *agent = data;
  73
  74   agent->inquire_maxlen = 0;
  75
  76   if (!strncmp (line, "INQUIRE_MAXLEN ", 15))
  77     {
  78       agent->inquire_maxlen = atoi (line + 15);
  79       if (!agent->client_ctx)
  80         return 0;
  81     }
  82
  83   return send_status (agent->client_ctx, STATUS_AGENT, "%s", line);
  84 }
  85
  86 static gpg_error_t
  87 assuan_command (struct agent_s *a, char **result,
  88                 size_t * len, const char *cmd)
  89 {
  90   gpg_error_t rc;
  91
  92   a->data.len = 0;
  93   a->data.buf = NULL;
  94   if (result)
  95     *result = NULL;
  96   if (len)
  97     *len = 0;
  98
  99   rc = assuan_transact (a->ctx, cmd, mem_realloc_cb, &a->data,
 100                         a->inquire_cb, a->inquire_data, status_cb, a);
 101   if (rc)
 102     xfree (a->data.buf);
 103   else
 104     {
 105       if (a->data.buf)
 106         {
 107           mem_realloc_cb (&a->data, "", 1);
 108           if (result)
 109             *result = (char *) a->data.buf;
 110           else
 111             xfree (a->data.buf);
 112
 113           if (len)
 114             *len = a->data.len;
 115         }
 116     }
 117
 118   return rc;
 119 }
 120
 121 /* This commands are sent from launch_agent() after reconnecting to the agent
 122  * and also from the initial client connection. */
 123 gpg_error_t
 124 send_agent_common_options (struct agent_s *agent)
 125 {
 126   gpg_error_t rc;
 127
 128   rc = send_to_agent (agent, NULL, NULL, "OPTION cache-ttl-opt-preset=-1");
 129   return rc;
 130 }
 131
 132 static gpg_error_t
 133 launch_agent (struct agent_s *agent)
 134 {
 135   gpg_error_t rc;
 136   assuan_context_t ctx = NULL;
 137   static struct assuan_malloc_hooks mhooks = { xmalloc, xrealloc, xfree };
 138   char *s;
 139
 140   agent->did_restart = 0;
 141   rc = assuan_new_ext (&ctx, GPG_ERR_SOURCE_DEFAULT, &mhooks,
 142                        debug_level ? assuan_log_cb : NULL, "AGENT ");
 143   if (rc)
 144     return rc;
 145
 146   s = config_get_string ("global", "gpg_agent_socket");
 147   rc = assuan_socket_connect (ctx, s, ASSUAN_INVALID_PID, 0);
 148   xfree (s);
 149   if (rc)
 150     {
 151       if (ctx)
 152         assuan_release (ctx);
 153       return rc;
 154     }
 155
 156   if (agent->ctx)
 157     assuan_release (agent->ctx);
 158
 159   agent->ctx = ctx;
 160   rc = send_agent_common_options (agent);
 161   if (!rc && agent->pinentry_opts.display)
 162     rc = set_agent_option (agent, "display", agent->pinentry_opts.display);
 163
 164   if (!rc && agent->pinentry_opts.ttyname)
 165     rc = set_agent_option (agent, "ttyname", agent->pinentry_opts.ttyname);
 166
 167   if (!rc && agent->pinentry_opts.ttytype)
 168     rc = set_agent_option (agent, "ttytype", agent->pinentry_opts.ttytype);
 169
 170   if (!rc && agent->pinentry_opts.lc_messages)
 171     rc = set_agent_option (agent, "lc-messages",
 172                            agent->pinentry_opts.lc_messages);
 173
 174   if (!rc && agent->pinentry_opts.lc_ctype)
 175     rc = set_agent_option (agent, "lc-ctype", agent->pinentry_opts.lc_ctype);
 176
 177   return rc;
 178 }
 179
 180 gpg_error_t
 181 send_to_agent (struct agent_s * agent, char **result, size_t * len,
 182                const char *fmt, ...)
 183 {
 184   gpg_error_t rc = 0;
 185   va_list ap;
 186   char *cmd;
 187
 188   if (!agent->ctx)
 189     {
 190       rc = launch_agent (agent);
 191       if (rc)
 192         return rc;
 193     }
 194
 195   va_start (ap, fmt);
 196   if (str_vasprintf (&cmd, fmt, ap) > 0)
 197     {
 198       rc = assuan_command (agent, result, len, cmd);
 199       if (!agent->restart && gpg_err_source (rc) == GPG_ERR_SOURCE_DEFAULT
 200           && (gpg_err_code (rc) == GPG_ERR_ASS_CONNECT_FAILED
 201               || gpg_err_code (rc) == GPG_ERR_EPIPE))
 202         {
 203           log_write (_ ("gpg-agent connection died (rc=%i), reconnecting"), rc);
 204           agent->restart = 1;
 205           rc = launch_agent (agent);
 206           if (!rc)
 207             {
 208               agent->did_restart = 1;
 209               rc = assuan_command (agent, result, len, cmd);
 210             }
 211         }
 212
 213       agent->restart = 0;
 214       xfree (cmd);
 215     }
 216   else
 217     rc = GPG_ERR_ENOMEM;
 218
 219   va_end (ap);
 220   return rc;
 221 }
 222
 223 static void
 224 agent_disconnect (struct agent_s *agent)
 225 {
 226   if (!agent)
 227     return;
 228
 229   if (agent->ctx)
 230     assuan_release (agent->ctx);
 231
 232   agent->ctx = NULL;
 233 }
 234
 235 void
 236 cleanup_agent (struct agent_s *agent)
 237 {
 238   if (!agent)
 239     return;
 240
 241   pinentry_free_opts (&agent->pinentry_opts);
 242   agent_disconnect (agent);
 243   xfree (agent);
 244 }
 245
 246 gpg_error_t
 247 agent_init (struct agent_s **agent)
 248 {
 249   struct agent_s *new = xcalloc (1, sizeof (struct agent_s));
 250
 251   if (!new)
 252     return GPG_ERR_ENOMEM;
 253
 254   *agent = new;
 255   return 0;
 256 }
 257
 258 static gpg_error_t
 259 inquire_cb (void *user, const char *keyword)
 260 {
 261   struct inquire_data_s *idata = user;
 262
 263   if (!idata->preset && (!strcmp (keyword, "PASSPHRASE")
 264                          || !strcmp (keyword, "NEW_PASSPHRASE")))
 265     {
 266       return agent_loopback_cb (idata->crypto, keyword);
 267     }
 268   // SAVE --inquire-keyparam
 269   else if (idata->preset && !strcmp (keyword, "KEYPARAM"))
 270     {
 271       idata->preset = 0;
 272       return agent_loopback_cb (idata->crypto, keyword);
 273     }
 274
 275   if (idata->crypto->agent->inquire_maxlen
 276       && idata->len > idata->crypto->agent->inquire_maxlen)
 277     {
 278       log_write (_("Inquired data too large: have=%u, max=%u"), idata->len,
 279                  idata->crypto->agent->inquire_maxlen);
 280       return GPG_ERR_TOO_LARGE;
 281     }
 282
 283   idata->crypto->agent->inquire_maxlen = 0;
 284   return assuan_send_data (idata->crypto->agent->ctx, idata->line,
 285                            idata->len);
 286 }
 287
 288 /* Retrieve the passphrase needed to decrypt the XML from the secret
 289  * key using gpg-agent. */
 290 gpg_error_t
 291 agent_extract_key (struct crypto_s *crypto, unsigned char **result,
 292                    size_t * result_len)
 293 {
 294   gpg_error_t rc;
 295   gcry_sexp_t enc_sexp = NULL, tmp_sexp;
 296   struct inquire_data_s idata = { 0 };
 297   char *hexgrip = NULL;
 298   char *key;
 299   size_t keylen, keysize;
 300   char *tmp;
 301   int algo = cipher_to_gcrypt (crypto->hdr.flags);
 302   int shadowed;
 303
 304   rc = gcry_cipher_algo_info (algo, GCRYCTL_GET_KEYLEN, NULL, &keysize);
 305   if (rc)
 306     return rc;
 307
 308   tmp_sexp = gcry_sexp_find_token (crypto->ciphertext_sexp, "enc-val", 0);
 309   if (!tmp_sexp)
 310     return gpg_error (GPG_ERR_BAD_DATA);
 311
 312   hexgrip = bin2hex (crypto->grip, sizeof (crypto->grip));
 313   if (!hexgrip)
 314     {
 315       rc = GPG_ERR_ENOMEM;
 316       goto fail;
 317     }
 318
 319   rc = cache_is_shadowed (hexgrip);
 320   if (rc && rc != GPG_ERR_NO_DATA)
 321     goto fail;
 322
 323   shadowed = !rc ? 1 : 0;
 324   if (!shadowed)
 325     {
 326       /* The key is not on a smartcard. */
 327       gcry_sexp_t tmp2_sexp = gcry_sexp_cdr (tmp_sexp);
 328       gcry_sexp_release (tmp_sexp);
 329       tmp_sexp = gcry_sexp_nth (tmp2_sexp, 0);
 330       gcry_sexp_release (tmp2_sexp);
 331       rc = gcry_sexp_build (&enc_sexp, NULL, "(enc-val (flags pkcs1) %S)",
 332                             tmp_sexp);
 333     }
 334   else
 335     rc = gcry_sexp_build (&enc_sexp, NULL, "%S", tmp_sexp);
 336
 337   gcry_sexp_release (tmp_sexp);
 338   if (rc)
 339     return rc;
 340
 341   crypto->agent->inquire_cb = inquire_cb;
 342   idata.crypto = crypto;
 343   idata.len = gcry_sexp_sprint (enc_sexp, GCRYSEXP_FMT_CANON, NULL, 0);
 344   idata.line = xmalloc (idata.len);
 345   if (!idata.line)
 346     {
 347       rc = GPG_ERR_ENOMEM;
 348       goto fail;
 349     }
 350
 351   idata.len = gcry_sexp_sprint (enc_sexp, GCRYSEXP_FMT_CANON, idata.line,
 352                                 idata.len);
 353   crypto->agent->inquire_data = &idata;
 354   gcry_sexp_release (enc_sexp);
 355   enc_sexp = NULL;
 356   log_write1 (_("Keygrip is %s, bits=%i"), hexgrip,
 357               gcry_pk_get_nbits (crypto->pkey_sexp));
 358   rc = send_to_agent (crypto->agent, NULL, NULL, "SETKEY %s", hexgrip);
 359   if (rc)
 360     goto fail;
 361
 362   if (!crypto->agent->pinentry_opts.desc)
 363     {
 364       tmp =
 365         plus_escape (_
 366                      ("A %s is required to unlock the secret key for the "
 367                       "encrypted data file \"%s\". Please enter the %s "
 368                       "below."), shadowed ? "PIN" : _("passphrase"),
 369                      crypto->filename, shadowed ? "PIN" : _("passphrase"));
 370     }
 371   else
 372     tmp = plus_escape (crypto->agent->pinentry_opts.desc);
 373
 374   rc = send_to_agent (crypto->agent, NULL, NULL, "SETKEYDESC %s", tmp);
 375   xfree (tmp);
 376   if (rc)
 377     goto fail;
 378
 379   assuan_begin_confidential (crypto->agent->ctx);
 380   rc = send_to_agent (crypto->agent, &key, &keylen, "PKDECRYPT");
 381   assuan_end_confidential (crypto->agent->ctx);
 382   if (rc)
 383     goto fail;
 384
 385   rc = gcry_sexp_new (&tmp_sexp, key, keylen, 1);
 386   xfree (key);
 387   if (rc)
 388     goto fail;
 389
 390   key = (char *) gcry_sexp_nth_data (tmp_sexp, 1, result_len);
 391   if (key)
 392     {
 393       *result = gcry_malloc (*result_len);
 394       if (!*result)
 395         rc = GPG_ERR_ENOMEM;
 396       else
 397         memcpy (*result, key, *result_len);
 398     }
 399   else
 400     rc = GPG_ERR_BAD_DATA;
 401
 402   gcry_sexp_release (tmp_sexp);
 403
 404 fail:
 405   xfree (idata.line);
 406   xfree (hexgrip);
 407
 408   if (enc_sexp)
 409     gcry_sexp_release (enc_sexp);
 410
 411   if (rc && gpg_err_source (rc) == GPG_ERR_SOURCE_UNKNOWN)
 412     rc = gpg_error (rc);
 413
 414   return rc;
 415 }
 416
 417 // FIXME
 418 /* Return an error for public key algorithms other than RSA or DSA or ELG.
 419  * Others are supported by libgcrypt but I dont know what to do for ECDA. Key
 420  * generation works as does signing but decryption fails for unsupported
 421  * algorithms so disable them. */
 422 static gpg_error_t
 423 get_key_info (gcry_sexp_t pubkey, char **hash_str, int *hash_type,
 424                size_t *len, int *pk_algo)
 425 {
 426   unsigned nbits = gcry_pk_get_nbits (pubkey);
 427   gcry_sexp_t sexp, tmp;
 428   char *algo;
 429   gpg_error_t rc = 0;
 430
 431   tmp = gcry_sexp_find_token (pubkey, "public-key", 0);
 432   if(!tmp)
 433     return GPG_ERR_NO_PUBKEY;
 434
 435   sexp = gcry_sexp_nth (tmp, 1);
 436   gcry_sexp_release (tmp);
 437   algo = gcry_sexp_nth_string (sexp, 0);
 438   gcry_sexp_release (sexp);
 439
 440   if (!algo)
 441     {
 442       return GPG_ERR_BAD_PUBKEY;
 443     }
 444
 445   if (!strcmp (algo, "rsa"))
 446     {
 447       *pk_algo = GCRY_PK_RSA;
 448       *hash_str = "sha256";
 449       *hash_type = GCRY_MD_SHA256;
 450       *len = gcry_md_get_algo_dlen (GCRY_MD_SHA256);
 451     }
 452   else if (!strcmp (algo, "elg"))
 453     {
 454       *pk_algo = GCRY_PK_ELG;
 455       *hash_str = "sha256";
 456       *hash_type = GCRY_MD_SHA256;
 457       *len = gcry_md_get_algo_dlen (GCRY_MD_SHA256);
 458     }
 459   else if (!strcmp (algo, "dsa"))
 460     {
 461       *pk_algo = GCRY_PK_DSA;
 462       switch (nbits)
 463         {
 464         default:
 465         case 512 ... 1024:
 466           *hash_str = "sha1";
 467           *hash_type = GCRY_MD_SHA1;
 468           *len = gcry_md_get_algo_dlen (GCRY_MD_SHA1);
 469           break;
 470         case 2048:
 471           *hash_str = "sha224";
 472           *hash_type = GCRY_MD_SHA224;
 473           *len = gcry_md_get_algo_dlen (GCRY_MD_SHA224);
 474           break;
 475         case 3072:
 476           *hash_str = "sha256";
 477           *hash_type = GCRY_MD_SHA256;
 478           *len = gcry_md_get_algo_dlen (GCRY_MD_SHA256);
 479           break;
 480         case 7680:
 481           *hash_str = "sha384";
 482           *hash_type = GCRY_MD_SHA384;
 483           *len = gcry_md_get_algo_dlen (GCRY_MD_SHA384);
 484           break;
 485         case 15360:
 486           *hash_str = "sha512";
 487           *hash_type = GCRY_MD_SHA512;
 488           *len = gcry_md_get_algo_dlen (GCRY_MD_SHA512);
 489           break;
 490         }
 491     }
 492   else
 493     rc = GPG_ERR_UNSUPPORTED_ALGORITHM;
 494
 495   gcry_free (algo);
 496   return rc;
 497 }
 498
 499 gpg_error_t
 500 agent_verify (gcry_sexp_t pkey, gcry_sexp_t sig_sexp, const void *data,
 501               size_t len)
 502 {
 503   size_t hashlen;
 504   int pk_algo;
 505   unsigned char *hash;
 506   gcry_sexp_t data_sexp;
 507   char *hash_str = NULL;
 508   int hash_type;
 509   gpg_error_t rc = get_key_info (pkey, &hash_str, &hash_type, &hashlen,
 510                                  &pk_algo);
 511
 512   if (rc)
 513     return rc;
 514
 515   hash = gcry_malloc (hashlen);
 516   if (!hash)
 517     return GPG_ERR_ENOMEM;
 518
 519   gcry_md_hash_buffer (hash_type, hash, data, len);
 520   if (pk_algo == GCRY_PK_RSA || pk_algo == GCRY_PK_ELG)
 521     rc = gcry_sexp_build (&data_sexp, NULL,
 522                           "(data (flags pkcs1) (hash %s %b))", hash_str,
 523                           hashlen, hash);
 524   else
 525     rc = gcry_sexp_build (&data_sexp, NULL,
 526                           "(data (flags raw) (value %b))", hashlen, hash);
 527
 528   gcry_free (hash);
 529   if (!rc)
 530     {
 531       rc = gcry_pk_verify (sig_sexp, data_sexp, pkey);
 532       gcry_sexp_release (data_sexp);
 533     }
 534
 535   return rc;
 536 }
 537
 538 /* Inquire data from the client. The inquire initiated from gpg-agent. */
 539 gpg_error_t
 540 agent_loopback_cb (void *user, const char *keyword)
 541 {
 542   struct crypto_s *crypto = user;
 543   gpg_error_t rc;
 544   unsigned char *result;
 545   size_t len;
 546   int keyparam = 0;
 547
 548   if (!strcmp (keyword, "KEYPARAM"))
 549     {
 550       keyparam = 1;
 551       rc = assuan_inquire (crypto->client_ctx, keyword, &result, &len, 0);
 552     }
 553   else
 554     {                           // PASSPHRASE or NEW_PASSPHRASE
 555       assuan_begin_confidential (crypto->client_ctx);
 556       rc = assuan_inquire (crypto->client_ctx, keyword, &result, &len, 0);
 557       assuan_end_confidential (crypto->client_ctx);
 558
 559       if (!rc && len == 1 && *result == 0)
 560         len = 0;
 561     }
 562
 563   if (!rc)
 564     {
 565       if (keyparam && !len)
 566         {
 567           char *tmp = default_key_params (crypto);
 568
 569           if (!tmp)
 570             return gpg_error (GPG_ERR_ENOMEM);
 571
 572           len = strlen (tmp);
 573           xfree (result);
 574           result = xmalloc (len);
 575           memcpy (result, tmp, len);
 576           xfree (tmp);
 577         }
 578
 579       pthread_cleanup_push (xfree, result);
 580
 581       if (keyparam)
 582         rc = assuan_send_data (crypto->agent->ctx, result, len);
 583       else
 584         {
 585           assuan_begin_confidential (crypto->agent->ctx);
 586           rc = assuan_send_data (crypto->agent->ctx, result, len);
 587           assuan_end_confidential (crypto->agent->ctx);
 588         }
 589
 590       pthread_cleanup_pop (1);
 591     }
 592   else if (gpg_err_code (rc) == GPG_ERR_ASS_CANCELED)
 593     {
 594       gpg_error_t arc = assuan_write_line (crypto->agent->ctx, "CAN");
 595
 596       if (!arc)
 597         {
 598           char *line;
 599           size_t len;
 600
 601           arc = assuan_read_line (crypto->agent->ctx, &line, &len);
 602           if (arc)
 603             rc = arc;
 604         }
 605       else
 606         rc = arc;
 607     }
 608
 609   return rc;
 610 }
 611
 612 static gpg_error_t
 613 sign (gcry_sexp_t * rsexp, gcry_sexp_t sigpkey, struct crypto_s *crypto,
 614       const void *data, size_t len)
 615 {
 616   gpg_error_t rc;
 617   char *result;
 618   unsigned char grip[20];
 619   char *tmp;
 620
 621   gcry_pk_get_keygrip (sigpkey, grip);
 622   tmp = bin2hex (grip, sizeof(grip));
 623   pthread_cleanup_push (xfree, tmp);
 624   log_write1 (_("Signed with keygrip %s"), tmp);
 625   rc = send_to_agent (crypto->agent, NULL, NULL, "SIGKEY %s", tmp);
 626   pthread_cleanup_pop (1);
 627   if (!rc)
 628     {
 629       size_t hashlen;
 630       char *hash_str = NULL;
 631       int hash_type;
 632       int pk_algo;
 633
 634       rc = get_key_info (sigpkey, &hash_str, &hash_type, &hashlen, &pk_algo);
 635       if (!rc)
 636         {
 637           unsigned char *hash = gcry_malloc (hashlen);
 638
 639           if (!hash)
 640             rc = gpg_error (GPG_ERR_ENOMEM);
 641
 642           if (!rc)
 643             {
 644               gcry_md_hash_buffer (hash_type, hash, data, len);
 645               tmp = bin2hex (hash, hashlen);
 646               gcry_free (hash);
 647               pthread_cleanup_push (xfree, tmp);
 648               rc = send_to_agent (crypto->agent, NULL, NULL,
 649                                   "SETHASH --hash=%s %s", hash_str, tmp);
 650               pthread_cleanup_pop (1);
 651             }
 652         }
 653     }
 654
 655   if (rc)
 656     return rc;
 657
 658   if (!rc)
 659     {
 660       struct inquire_data_s idata = { 0 };
 661
 662       idata.crypto = crypto;
 663       crypto->agent->inquire_data = &idata;
 664       crypto->agent->inquire_cb = inquire_cb;
 665       rc = send_to_agent (crypto->agent, &result, &len, "PKSIGN");
 666       if (!rc)
 667         {
 668           rc = gcry_sexp_sscan (rsexp, NULL, result, len);
 669           xfree (result);
 670         }
 671     }
 672
 673   if (rc && gpg_err_source (rc) == GPG_ERR_SOURCE_UNKNOWN)
 674     rc = gpg_error (rc);
 675
 676   return rc;
 677 }
 678
 679 /* Encrypt the data file to 'pubkey' and sign with 'sigpkey'. */
 680 gpg_error_t
 681 encrypt_data_file (assuan_context_t ctx, struct crypto_s * crypto,
 682                    gcry_sexp_t pubkey, gcry_sexp_t sigpkey,
 683                    const char *filename, const void *xml, size_t len)
 684 {
 685   gpg_error_t rc;
 686   void *data = NULL;
 687   size_t data_len = 0;
 688   void *enc_xml = NULL;
 689   size_t enc_xml_len = 0;
 690   unsigned char *iv = NULL;
 691   size_t iv_len = 0;
 692   int algo = cipher_to_gcrypt (crypto->save.hdr.flags);
 693   void *key = NULL;
 694   size_t keysize;
 695   unsigned char sig_grip[20];
 696   unsigned char grip[20];
 697
 698   rc = gcry_cipher_algo_info (algo, GCRYCTL_GET_KEYLEN, NULL, &keysize);
 699   if (rc)
 700     return rc;
 701
 702   pthread_cleanup_push (gcry_free, key);
 703   key = gcry_random_bytes_secure (keysize, GCRY_STRONG_RANDOM);
 704 #ifdef HAVE_PTHREAD_TESTCANCEL
 705   pthread_testcancel ();        // may have been a long operation
 706 #endif
 707   pthread_cleanup_pop (0);
 708   if (!key)
 709     return gpg_error (GPG_ERR_ENOMEM);
 710
 711   gcry_pk_get_keygrip (pubkey, grip);
 712   gcry_pk_get_keygrip (sigpkey, sig_grip);
 713   pthread_cleanup_push (gcry_free, key);
 714   rc = encrypt_xml (ctx, key, keysize, algo, xml, len, &enc_xml, &enc_xml_len,
 715                     &iv, &iv_len, crypto->save.hdr.iterations);
 716   if (!rc)
 717     {
 718       gcry_sexp_t sig_sexp = NULL;
 719       char *hexgrip = bin2hex (grip, 20);
 720
 721       pthread_cleanup_push (xfree, iv);
 722       log_write1 (_("Encrypted with keygrip %s"), hexgrip);
 723       xfree (hexgrip);
 724       hexgrip = bin2hex (sig_grip, 20);
 725       pthread_cleanup_push (gcry_free, enc_xml);
 726       rc = sign (&sig_sexp, sigpkey, crypto, enc_xml, enc_xml_len);
 727       xfree (hexgrip);
 728
 729       if (!rc)
 730         {
 731           rc = agent_verify (sigpkey, sig_sexp, enc_xml, enc_xml_len);
 732           if (!rc)
 733             {
 734               gcry_sexp_t tmp_sexp;
 735
 736               rc = gcry_sexp_build (&tmp_sexp, NULL,
 737                                     "(data (flags pkcs1) (value %b))",
 738                                     keysize, key);
 739               if (!rc)
 740                 {
 741                   gcry_sexp_t key_sexp;
 742
 743                   pthread_cleanup_push ((void (*)(void *)) gcry_sexp_release,
 744                                         (void *) sig_sexp);
 745                   rc = gcry_pk_encrypt (&key_sexp, tmp_sexp, pubkey);
 746                   pthread_cleanup_pop (0);
 747                   gcry_sexp_release (tmp_sexp);
 748
 749                   if (!rc)
 750                     {
 751                       memcpy (crypto->save.hdr.iv, iv, iv_len);
 752                       crypto->save.hdr.datalen = enc_xml_len;
 753                       rc = gcry_sexp_build (&tmp_sexp, NULL, "%S%S", key_sexp,
 754                                             sig_sexp);
 755                       gcry_sexp_release (key_sexp);
 756
 757                       if (!rc)
 758                         {
 759                           data_len = gcry_sexp_sprint (tmp_sexp,
 760                                                        GCRYSEXP_FMT_CANON,
 761                                                        NULL, 0);
 762                           data = xmalloc (data_len);
 763                           if (data)
 764                             gcry_sexp_sprint (tmp_sexp, GCRYSEXP_FMT_CANON,
 765                                               data, data_len);
 766                           else
 767                             rc = GPG_ERR_ENOMEM;
 768
 769                           gcry_sexp_release (tmp_sexp);
 770                         }
 771                     }
 772                 }
 773             }
 774         }
 775
 776       pthread_cleanup_pop (0);  // enc_xml
 777       pthread_cleanup_pop (1);  // iv
 778
 779       if (sig_sexp)
 780         gcry_sexp_release (sig_sexp);
 781     }
 782
 783   pthread_cleanup_pop (1);      // key
 784
 785   if (!rc)
 786     {
 787       pthread_cleanup_push (gcry_free, enc_xml);
 788       rc = write_file (crypto, filename, enc_xml, enc_xml_len, data, data_len,
 789                        pubkey, sigpkey);
 790       pthread_cleanup_pop (1);  // enc_xml
 791       if (!rc)
 792         memcpy (&crypto->hdr, &crypto->save.hdr, sizeof (file_header_t));
 793     }
 794
 795   xfree (data);
 796   if (rc && gpg_err_source (rc) == GPG_ERR_SOURCE_UNKNOWN)
 797     rc = gpg_error (rc);
 798
 799   return rc;
 800 }
 801
 802 /* Generated a new keypair from the key parameters in 'sexpstr'. */
 803 gpg_error_t
 804 generate_key (struct crypto_s * crypto, char *sexpstr, int empty, int preset)
 805 {
 806   gpg_error_t rc;
 807   char *pkey;
 808   size_t plen;
 809
 810   if (crypto->save.s2k_count)
 811     {
 812       rc = send_to_agent (crypto->agent, NULL, NULL,
 813                           "OPTION s2k-count=%lu", crypto->save.s2k_count);
 814       if (rc)
 815         return rc;
 816     }
 817
 818   if (!crypto->agent->inquire_cb)
 819     crypto->agent->inquire_cb = inquire_cb;
 820
 821   rc = send_to_agent (crypto->agent, &pkey, &plen, "GENKEY %s%s",
 822                       preset ? "--preset " : "",
 823                       empty ? "--no-protection" : "");
 824   if (rc)
 825     return rc;
 826
 827   if (crypto->save.pkey)
 828     gcry_sexp_release (crypto->save.pkey);
 829
 830   crypto->save.pkey = NULL;
 831   rc = gcry_sexp_new (&crypto->save.pkey, pkey, plen, 1);
 832   if (!rc)
 833     {
 834       unsigned char grip[20];
 835
 836       gcry_pk_get_keygrip (crypto->save.pkey, grip);
 837       char *hexgrip = bin2hex (grip, sizeof (grip));
 838       log_write (_("Keygrip is %s"), hexgrip);
 839       xfree (hexgrip);
 840
 841       if (!crypto->save.sigpkey)
 842         {
 843           gcry_sexp_build ((gcry_sexp_t *) & crypto->save.sigpkey, NULL, "%S",
 844                            crypto->save.pkey);
 845         }
 846     }
 847
 848   xfree (pkey);
 849   return rc;
 850 }
 851
 852 gpg_error_t
 853 set_agent_option (struct agent_s * agent, const char *name, const char *value)
 854 {
 855   return send_to_agent (agent, NULL, NULL, "OPTION %s=%s", name, value);
 856 }
 857
 858 gpg_error_t
 859 set_agent_passphrase (struct crypto_s * crypto, const char *key, size_t len)
 860 {
 861   char *hexgrip;
 862   struct inquire_data_s idata;
 863   gpg_error_t rc;
 864   int i;
 865
 866   /* This is for use with key files or passphrases obtained from an inquire.
 867    * gpg-agent uses strings as passphrases and will truncate the passphrase
 868    * at the first encountered null byte.  It's only a warning because the
 869    * passphrase may belong to a key shared outside of pwmd. */
 870   for (i = 0; i < len; i++)
 871     {
 872       if (key[i] == 0)
 873         {
 874           log_write (_("WARNING: keylen=%i, truncated to %i."), len, i);
 875           break;
 876         }
 877     }
 878
 879   hexgrip = bin2hex (crypto->grip, 20);
 880   crypto->agent->inquire_cb = inquire_cb;
 881   crypto->agent->inquire_data = &idata;
 882   idata.crypto = crypto;
 883   idata.line = (char *) key, idata.len = len;
 884   idata.preset = 1;
 885   assuan_begin_confidential (crypto->agent->ctx);
 886   rc = send_to_agent (crypto->agent, NULL, NULL,
 887                       "PRESET_PASSPHRASE --inquire %s -1", hexgrip);
 888   assuan_end_confidential (crypto->agent->ctx);
 889   idata.preset = 0;
 890   xfree (hexgrip);
 891   return rc;
 892 }
 893
 894 gpg_error_t
 895 set_pinentry_mode (struct agent_s * agent, const char *mode)
 896 {
 897   return set_agent_option (agent, "pinentry-mode", mode);
 898 }
 899
 900 gpg_error_t
 901 get_pubkey_bin (struct crypto_s * crypto, const unsigned char *grip,
 902                 gcry_sexp_t * result)
 903 {
 904   char *hexgrip = bin2hex (grip, 20);
 905   gpg_error_t rc;
 906
 907   if (!hexgrip)
 908     return GPG_ERR_ENOMEM;
 909
 910   rc = get_pubkey (crypto, hexgrip, result);
 911   xfree (hexgrip);
 912   return rc;
 913 }
 914
 915 gpg_error_t
 916 get_pubkey (struct crypto_s * crypto, const char *grip, gcry_sexp_t * result)
 917 {
 918   char *pkey = NULL;
 919   size_t plen;
 920   gpg_error_t rc;
 921
 922   rc = send_to_agent (crypto->agent, &pkey, &plen, "READKEY %s", grip);
 923   if (!rc)
 924     rc = gcry_sexp_new (result, pkey, plen, 1);
 925
 926   xfree (pkey);
 927   return rc;
 928 }
 929
 930 gpg_error_t
 931 agent_set_pinentry_options (struct agent_s * agent)
 932 {
 933   gpg_error_t rc = 0;
 934   struct pinentry_option_s *opts = &agent->pinentry_opts;
 935
 936   if (!opts->display && getenv ("DISPLAY"))
 937     {
 938       rc = set_agent_option (agent, "display", getenv ("DISPLAY"));
 939       if (!rc)
 940         {
 941           opts->display = str_dup (getenv ("DISPLAY"));
 942         }
 943     }
 944   else if (!opts->ttyname && ttyname (STDOUT_FILENO))
 945     {
 946       rc = set_agent_option (agent, "ttyname", ttyname (STDOUT_FILENO));
 947       if (!rc)
 948         {
 949           rc = set_agent_option (agent, "ttytype",
 950                                  opts->ttytype ? opts->ttytype : getenv ("TERM"));
 951           if (!rc)
 952             {
 953               xfree (opts->ttyname);
 954               xfree (opts->ttytype);
 955               opts->ttyname = str_dup (ttyname (STDOUT_FILENO));
 956               opts->ttytype = str_dup (getenv ("TERM"));
 957             }
 958         }
 959     }
 960
 961   return rc;
 962 }
 963
 964 static gpg_error_t
 965 inquire_keyfile (void *user, const char *keyword)
 966 {
 967   struct crypto_s *crypto = user;
 968   char *filename = crypto->agent->inquire_data2;
 969   char *params = crypto->agent->inquire_data3;
 970   int fd;
 971   struct stat st;
 972   unsigned char *buf;
 973   gpg_error_t rc;
 974
 975   if (!strcmp (keyword, "KEYPARAM"))
 976     return assuan_send_data (crypto->agent->ctx, params, strlen (params));
 977
 978   // This function is only used when generating a new keypair.
 979   if (strcmp (keyword, "NEW_PASSPHRASE"))
 980     return gpg_error (GPG_ERR_ASS_UNKNOWN_INQUIRE);
 981
 982   if (stat (filename, &st) == -1)
 983     return gpg_error_from_errno (errno);
 984
 985   if (crypto->agent->inquire_maxlen
 986       && st.st_size > crypto->agent->inquire_maxlen)
 987     {
 988       log_write (_("The passphrase is too large: have=%u, max=%u."),
 989                  (unsigned) st.st_size, crypto->agent->inquire_maxlen);
 990       return GPG_ERR_TOO_LARGE;
 991     }
 992
 993   buf = gcry_malloc_secure (st.st_size);
 994   if (!buf)
 995     return GPG_ERR_ENOMEM;
 996
 997   fd = open (filename, O_RDONLY);
 998   if (fd == -1)
 999     rc = gpg_error_from_errno (errno);
1000   else
1001     {
1002       size_t len = read (fd, buf, st.st_size);
1003
1004       if (len == st.st_size)
1005         {
1006           assuan_begin_confidential (crypto->agent->ctx);
1007           rc = assuan_send_data (crypto->agent->ctx, buf, len);
1008           assuan_end_confidential (crypto->agent->ctx);
1009         }
1010       else if (len == -1)
1011         rc = gpg_error_from_errno (errno);
1012       else
1013         rc = GPG_ERR_BUFFER_TOO_SHORT;
1014     }
1015
1016   close (fd);
1017   gcry_free (buf);
1018   return rc;
1019 }
1020
1021 gpg_error_t
1022 agent_export_common (struct crypto_s * crypto, const char *hexgrip,
1023                      const char *sign_hexgrip, int no_passphrase,
1024                      const void *data, size_t datalen, const char *outfile,
1025                      const char *keyparams, const char *keyfile)
1026 {
1027   gpg_error_t rc = 0;
1028
1029   if (!sign_hexgrip && hexgrip)
1030     sign_hexgrip = hexgrip;
1031
1032   if (sign_hexgrip)
1033     {
1034       if (crypto->sigpkey_sexp)
1035         gcry_sexp_release (crypto->sigpkey_sexp);
1036
1037       crypto->sigpkey_sexp = NULL;
1038       rc = get_pubkey (crypto, sign_hexgrip, &crypto->save.sigpkey);
1039       if (rc)
1040         return rc;
1041
1042       gcry_pk_get_keygrip (crypto->save.sigpkey, crypto->sign_grip);
1043     }
1044
1045   if (hexgrip)
1046     {
1047       rc = get_pubkey (crypto, hexgrip, &crypto->save.pkey);
1048       if (!rc)
1049         gcry_pk_get_keygrip (crypto->save.pkey, crypto->grip);
1050     }
1051   else
1052     {
1053       struct inquire_data_s idata = { 0 };
1054       char *params = keyparams ? str_dup (keyparams)
1055         : default_key_params (crypto);
1056
1057       pthread_cleanup_push (xfree, params);
1058       log_write (_("Generating a new keypair ..."));
1059       if (keyfile)
1060         {
1061           log_write (_("Using passphrase obtained from file '%s'"), keyfile);
1062           rc = set_pinentry_mode (crypto->agent, "loopback");
1063           crypto->agent->inquire_cb = inquire_keyfile;
1064           crypto->agent->inquire_data = crypto;
1065           crypto->agent->inquire_data2 = (char *) keyfile;
1066           crypto->agent->inquire_data3 = params;
1067         }
1068       else
1069         {
1070           idata.line = params;
1071           idata.len = strlen (params);
1072           idata.crypto = crypto;
1073           crypto->agent->inquire_cb = inquire_cb;
1074           crypto->agent->inquire_data = &idata;
1075         }
1076
1077       if (!rc)
1078         {
1079           rc = generate_key (crypto, params, no_passphrase, 1);
1080           if (!rc)
1081             gcry_pk_get_keygrip (crypto->save.pkey, crypto->grip);
1082         }
1083
1084       (void) set_pinentry_mode (crypto->agent, "ask");
1085       pthread_cleanup_pop (1);
1086     }
1087
1088   if (!rc)
1089     {
1090       rc = encrypt_data_file (NULL, crypto, crypto->save.pkey,
1091                               crypto->save.sigpkey, outfile, data, datalen);
1092       if (!rc)
1093         {
1094           char *tmp = bin2hex (crypto->grip, sizeof (crypto->grip));
1095
1096           log_write (_("Success! Keygrip is %s."), tmp);
1097           rc = send_to_agent (crypto->agent, NULL, NULL,
1098                               "CLEAR_PASSPHRASE --mode=normal %s", tmp);
1099           xfree (tmp);
1100
1101           if (sign_hexgrip)
1102             {
1103               tmp = bin2hex (crypto->sign_grip, sizeof (crypto->sign_grip));
1104               log_write (_("Signed with keygrip %s."), tmp);
1105               xfree (tmp);
1106             }
1107         }
1108     }
1109
1110   if (rc && gpg_err_source (rc) == GPG_ERR_SOURCE_UNKNOWN)
1111     rc = gpg_error (rc);
1112
1113   return rc;
1114 }
1115
1116 char *
1117 default_key_params (struct crypto_s *crypto)
1118 {
1119   return config_get_string (NULL, "keyparam");
1120 }
1121
1122 gpg_error_t
1123 agent_passwd (struct crypto_s * crypto)
1124 {
1125   struct inquire_data_s idata = { 0 };
1126   gpg_error_t rc;
1127   char *tmp = bin2hex (crypto->grip, 20);
1128
1129   idata.crypto = crypto;
1130   crypto->agent->inquire_cb = inquire_cb;
1131   crypto->agent->inquire_data = &idata;
1132   rc = send_to_agent (crypto->agent, NULL, NULL, "PASSWD --preset %s", tmp);
1133   xfree (tmp);
1134   return rc;
1135 }
1136
1137 gpg_error_t
1138 kill_scd (struct agent_s * agent)
1139 {
1140   gpg_error_t rc = 0;
1141
1142   if (!use_agent)
1143     return 0;
1144
1145   if (config_get_boolean (NULL, "kill_scd"))
1146     {
1147       rc = send_to_agent (agent, NULL, NULL, "SCD KILLSCD");
1148       if (rc && gpg_err_code (rc) != GPG_ERR_NO_SCDAEMON)
1149         log_write ("%s: %s", __FUNCTION__, pwmd_strerror (rc));
1150     }
1151
1152   return rc;
1153 }