src/libpwmd.c

   1 /* vim:tw=78:ts=8:sw=4:set ft=c:  */
   2 /*
   3     Copyright (C) 2006-2009 Ben Kibbey <bjk@luxsci.net>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02110-1301  USA
  18 */
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <err.h>
  23 #include <errno.h>
  24 #include <ctype.h>
  25 #include <string.h>
  26 #include <sys/socket.h>
  27 #include <sys/un.h>
  28 #include <signal.h>
  29 #include <stdarg.h>
  30 #include <string.h>
  31 #include <sys/wait.h>
  32 #include <fcntl.h>
  33 #include <pwd.h>
  34 #include <time.h>
  35 #include <sys/types.h>
  36 #include <limits.h>
  37 #include <sys/select.h>
  38 #include <netdb.h>
  39 #include <netinet/in.h>
  40 #include <sys/socket.h>
  41 #include <libpwmd.h>
  42
  43 #ifdef HAVE_CONFIG_H
  44 #include <config.h>
  45 #endif
  46
  47 #ifdef WITH_LIBPTH
  48 #include <pth.h>
  49 #endif
  50
  51 #ifdef WITH_TCP
  52 #define DNS_USE_GETTIMEOFDAY_FOR_ID 1
  53 #include <ares.h>
  54 #include <arpa/nameser.h>
  55 #ifdef WITH_LIBPTH
  56 #include <gcrypt.h>
  57 GCRY_THREAD_OPTION_PTH_IMPL;
  58 #endif
  59 #endif
  60
  61 #ifdef HAVE_ASSUAN_H
  62 #include <assuan.h>
  63 #endif
  64
  65 #ifdef HAVE_SETLOCALE
  66 #include <locale.h>
  67 #endif
  68
  69 #include "gettext.h"
  70 #define N_(msgid)       dgettext("libpwmd", msgid)
  71
  72 #include "mem.h"
  73 #include "types.h"
  74
  75 #ifdef WITH_PINENTRY
  76 static pwm_t *gpwm;
  77 static int gelapsed, gtimeout;
  78 static gpg_error_t pinentry_command(pwm_t *pwm, char **result, const char *cmd);
  79 static gpg_error_t global_error;
  80 #endif
  81
  82 const char *pwmd_strerror(gpg_error_t e)
  83 {
  84     gpg_err_code_t code = gpg_err_code(e);
  85
  86     if (code >= GPG_ERR_USER_1 && code < gpg_err_code(EPWMD_MAX)) {
  87         switch (code) {
  88             case GPG_ERR_USER_1:
  89             default:
  90                 return N_("Unknown error");
  91             case GPG_ERR_USER_2:
  92                 return N_("No cache slots available");
  93             case GPG_ERR_USER_3:
  94                 return N_("Recursion loop");
  95             case GPG_ERR_USER_4:
  96                 return N_("No file is open");
  97             case GPG_ERR_USER_5:
  98                 return N_("General LibXML error");
  99             case GPG_ERR_USER_6:
 100                 return N_("File modified");
 101             case GPG_ERR_USER_7:
 102                 return N_("Access denied");
 103         }
 104     }
 105
 106     return gpg_strerror(e);
 107 }
 108
 109 gpg_error_t pwmd_init()
 110 {
 111     static int initialized;
 112
 113     if (initialized)
 114         return 0;
 115
 116 #ifdef WITH_LIBPTH
 117     gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_pth);
 118 #endif
 119 #ifndef MEM_DEBUG
 120     xmem_init();
 121 #endif
 122 #ifdef ENABLE_NLS
 123     bindtextdomain("libpwmd", LOCALEDIR);
 124 #endif
 125     gpg_err_init();
 126     assuan_set_malloc_hooks(xmalloc, xrealloc, xfree);
 127     assuan_set_assuan_err_source(GPG_ERR_SOURCE_DEFAULT);
 128     initialized = 1;
 129     return 0;
 130 }
 131
 132 static pwm_t *_socket_connect_finalize(pwm_t *pwm, assuan_context_t ctx)
 133 {
 134     int active[2];
 135     int n = assuan_get_active_fds(ctx, 0, active, sizeof(active));
 136
 137     pwm->fd = n <= 0 ? -1 : dup(active[0]);
 138     pwm->ctx = ctx;
 139 #ifdef WITH_PINENTRY
 140     pwm->pid = -1;
 141     pwm->pinentry_tries = 3;
 142 #endif
 143     assuan_set_pointer(ctx, pwm);
 144     return pwm;
 145 }
 146
 147 #ifdef WITH_TCP
 148 static int read_hook(assuan_context_t ctx, assuan_fd_t fd, void *data,
 149         size_t len, ssize_t *ret)
 150 {
 151     pwm_t *pwm = assuan_get_pointer(ctx);
 152
 153     if (!pwm || !pwm->tcp_conn)
 154         *ret = read((int)fd, data, len);
 155     else {
 156         do {
 157             *ret = libssh2_channel_read(pwm->tcp_conn->channel, data, len);
 158         } while (*ret == LIBSSH2_ERROR_EAGAIN);
 159     }
 160
 161     return *ret <= 0 ? 0 : 1;
 162 }
 163
 164 static int write_hook(assuan_context_t ctx, assuan_fd_t fd, const void *data,
 165         size_t len, ssize_t *ret)
 166 {
 167     pwm_t *pwm = assuan_get_pointer(ctx);
 168
 169     if (!pwm || !pwm->tcp_conn)
 170         *ret = write((int)fd, data, len);
 171     else {
 172         do {
 173             *ret = libssh2_channel_write(pwm->tcp_conn->channel, data, len);
 174         } while (*ret == LIBSSH2_ERROR_EAGAIN);
 175     }
 176
 177     return *ret <= 0 ? 0 : 1;
 178 }
 179
 180 static void _ssh_deinit(pwmd_tcp_conn_t *conn);
 181 static void free_tcp_conn(pwmd_tcp_conn_t *conn)
 182 {
 183     if (!conn)
 184         return;
 185
 186     if (conn->username) {
 187         xfree(conn->username);
 188         conn->username = NULL;
 189     }
 190
 191     if (conn->known_hosts) {
 192         xfree(conn->known_hosts);
 193         conn->known_hosts = NULL;
 194     }
 195
 196     if (conn->identity) {
 197         xfree(conn->identity);
 198         conn->identity = NULL;
 199     }
 200
 201     if (conn->identity_pub) {
 202         xfree(conn->identity_pub);
 203         conn->identity_pub = NULL;
 204     }
 205
 206     if (conn->host) {
 207         xfree(conn->host);
 208         conn->host = NULL;
 209     }
 210
 211     if (conn->hostkey) {
 212         xfree(conn->hostkey);
 213         conn->hostkey = NULL;
 214     }
 215
 216     if (conn->chan) {
 217         ares_destroy(conn->chan);
 218         conn->chan = NULL;
 219     }
 220
 221     if (conn->he) {
 222         ares_free_hostent(conn->he);
 223         conn->he = NULL;
 224     }
 225
 226     if (conn->fd >= 0) {
 227         close(conn->fd);
 228         conn->fd = -1;
 229     }
 230
 231     if (conn->session)
 232         _ssh_deinit(conn);
 233     else
 234         xfree(conn);
 235 }
 236
 237 static void _ssh_deinit(pwmd_tcp_conn_t *conn)
 238 {
 239     if (!conn)
 240         return;
 241
 242     if (conn->channel)
 243         libssh2_channel_free(conn->channel);
 244
 245     if (conn->session) {
 246         libssh2_session_disconnect(conn->session, "Bye!");
 247         libssh2_session_free(conn->session);
 248     }
 249
 250     conn->session = NULL;
 251     conn->channel = NULL;
 252     free_tcp_conn(conn);
 253 }
 254
 255 static void _ssh_assuan_deinit(assuan_context_t ctx)
 256 {
 257     pwm_t *pwm = assuan_get_pointer(ctx);
 258
 259     _ssh_deinit(pwm->tcp_conn);
 260     pwm->tcp_conn = NULL;
 261 }
 262
 263 /*
 264  * Sets common options from both pwmd_tcp_connect() and
 265  * pwmd_tcp_connect_async().
 266  */
 267 static gpg_error_t init_tcp_conn(pwmd_tcp_conn_t **dst, const char *host,
 268         int port, const char *identity, const char *user, const char *hosts,
 269         int get)
 270 {
 271     pwmd_tcp_conn_t *conn;
 272     gpg_error_t rc = 0;
 273
 274     if (get) {
 275         if (!host)
 276             return GPG_ERR_INV_ARG;
 277     }
 278     else {
 279         if (!host || !identity || !user || !hosts)
 280             return GPG_ERR_INV_ARG;
 281     }
 282
 283     conn = xcalloc(1, sizeof(pwmd_tcp_conn_t));
 284
 285     if (!conn)
 286         return gpg_error_from_errno(ENOMEM);
 287
 288     conn->port = port == -1 ? 22 : port;
 289     conn->host = xstrdup(host);
 290
 291     if (!conn->host) {
 292         rc = gpg_error_from_errno(ENOMEM);
 293         goto fail;
 294     }
 295
 296     if (!get) {
 297         conn->identity = xstrdup(identity);
 298
 299         if (!conn->identity) {
 300             rc = gpg_error_from_errno(ENOMEM);
 301             goto fail;
 302         }
 303
 304         conn->identity_pub = xmalloc(strlen(conn->identity)+5);
 305
 306         if (!conn->identity_pub) {
 307             rc = gpg_error_from_errno(ENOMEM);
 308             goto fail;
 309         }
 310
 311         sprintf(conn->identity_pub, "%s.pub", conn->identity);
 312         conn->username = xstrdup(user);
 313
 314         if (!conn->username) {
 315             rc = gpg_error_from_errno(ENOMEM);
 316             goto fail;
 317         }
 318
 319         conn->known_hosts = xstrdup(hosts);
 320
 321         if (!conn->known_hosts) {
 322             rc = gpg_error_from_errno(ENOMEM);
 323             goto fail;
 324         }
 325     }
 326
 327     *dst = conn;
 328     return 0;
 329
 330 fail:
 331     free_tcp_conn(conn);
 332     return rc;
 333 }
 334
 335 static gpg_error_t do_connect(pwm_t *pwm, int prot, void *addr)
 336 {
 337     struct sockaddr_in their_addr;
 338
 339     pwm->tcp_conn->fd = socket(prot, SOCK_STREAM, 0);
 340
 341     if (pwm->tcp_conn->fd == -1)
 342         return gpg_error_from_syserror();
 343
 344     if (pwm->tcp_conn->async)
 345         fcntl(pwm->tcp_conn->fd, F_SETFL, O_NONBLOCK);
 346
 347     pwm->cmd = ASYNC_CMD_CONNECT;
 348     their_addr.sin_family = prot;
 349     their_addr.sin_port = htons(pwm->tcp_conn->port);
 350     their_addr.sin_addr = *((struct in_addr *)addr);
 351     memset(their_addr.sin_zero, '\0', sizeof their_addr.sin_zero);
 352
 353 #ifdef WITH_LIBPTH
 354     if (pth_connect(pwm->tcp_conn->fd, (struct sockaddr *)&their_addr,
 355                 sizeof(their_addr)) == -1)
 356 #else
 357     if (connect(pwm->tcp_conn->fd, (struct sockaddr *)&their_addr,
 358                 sizeof(their_addr)) == -1)
 359 #endif
 360         return gpg_error_from_syserror();
 361
 362     return 0;
 363 }
 364
 365 static gpg_error_t ares_error_to_pwmd(int status)
 366 {
 367     if (status != ARES_SUCCESS)
 368         warnx("%s", ares_strerror(status));
 369
 370     switch (status) {
 371         case ARES_ENODATA:
 372         case ARES_EFORMERR:
 373         case ARES_ENOTFOUND:
 374             return GPG_ERR_UNKNOWN_HOST;
 375         case ARES_ESERVFAIL:
 376              return GPG_ERR_EHOSTDOWN;
 377         case ARES_ETIMEOUT:
 378             return GPG_ERR_TIMEOUT;
 379         case ARES_ENOMEM:
 380             return gpg_error_from_errno(ENOMEM);
 381         case ARES_ECONNREFUSED:
 382             return GPG_ERR_ECONNREFUSED;
 383         default:
 384             /* FIXME ??? */
 385             return GPG_ERR_EHOSTUNREACH;
 386     }
 387
 388     return ARES_SUCCESS;
 389 }
 390
 391 static void dns_resolve_cb(void *arg, int status, int timeouts,
 392         unsigned char *abuf, int alen)
 393 {
 394     pwm_t *pwm = arg;
 395     int rc;
 396     struct hostent *he;
 397
 398     if (status == ARES_EDESTRUCTION)
 399         return;
 400
 401     if (status != ARES_SUCCESS) {
 402         pwm->tcp_conn->rc = ares_error_to_pwmd(status);
 403         return;
 404     }
 405
 406     //FIXME localhost. works with ipv4. maybe local system config error
 407     /* Check for an IPv6 address first. */
 408     rc = ares_parse_a_reply(abuf, alen, &he, NULL, NULL);
 409
 410     if (rc != ARES_SUCCESS) {
 411         if (rc != ARES_ENODATA) {
 412             pwm->tcp_conn->rc = ares_error_to_pwmd(status);
 413             return;
 414         }
 415
 416         rc = ares_parse_aaaa_reply(abuf, alen, &he, NULL, NULL);
 417
 418         if (rc != ARES_SUCCESS) {
 419             pwm->tcp_conn->rc = ares_error_to_pwmd(status);
 420             return;
 421         }
 422     }
 423
 424     pwm->tcp_conn->he = he;
 425     pwm->tcp_conn->rc = do_connect(pwm, he->h_addrtype, he->h_addr);
 426 }
 427
 428 pwm_t *_do_pwmd_tcp_connect_async(const char *host, int port,
 429         const char *identity, const char *user, const char *known_hosts,
 430         gpg_error_t *rc, pwmd_async_cmd_t which)
 431 {
 432     pwmd_tcp_conn_t *conn;
 433     pwm_t *pwm;
 434
 435     *rc = init_tcp_conn(&conn, host, port, identity, user, known_hosts,
 436             which == ASYNC_CMD_HOSTKEY ? 1 : 0);
 437
 438     if (*rc)
 439         return NULL;
 440
 441     if ((pwm = (pwm_t *)xcalloc(1, sizeof(pwm_t))) == NULL) {
 442         *rc = gpg_error_from_syserror();
 443         free_tcp_conn(conn);
 444         return NULL;
 445     }
 446
 447     conn->async = 1;
 448     pwm->tcp_conn = conn;
 449     pwm->tcp_conn->cmd = which;
 450
 451     if (pwm->tcp_conn->cmd == ASYNC_CMD_HOSTKEY)
 452         pwm->tcp_conn->get_only = 1;
 453
 454     pwm->cmd = ASYNC_CMD_DNS;
 455     pwm->state = ASYNC_PROCESS;
 456     ares_init(&pwm->tcp_conn->chan);
 457     ares_query(pwm->tcp_conn->chan, pwm->tcp_conn->host, ns_c_any, ns_t_any,
 458             dns_resolve_cb, pwm);
 459     return pwm;
 460 }
 461
 462 pwm_t *pwmd_tcp_connect_async(const char *host, int port, const char *identity,
 463         const char *user, const char *known_hosts, gpg_error_t *rc)
 464 {
 465     return _do_pwmd_tcp_connect_async(host, port, identity, user, known_hosts,
 466             rc, ASYNC_CMD_CONNECT);
 467 }
 468
 469 void *_ssh_malloc(size_t size, void **data)
 470 {
 471     return xmalloc(size);
 472 }
 473
 474 void _ssh_free(void *ptr, void **data)
 475 {
 476     xfree(ptr);
 477 }
 478
 479 void *_ssh_realloc(void *ptr, size_t size, void **data)
 480 {
 481     return xrealloc(ptr, size);
 482 }
 483
 484 static char *to_hex(const char *str, size_t slen)
 485 {
 486     int i;
 487     char *buf = xmalloc(slen*2+1);
 488
 489     if (!buf)
 490         return NULL;
 491
 492     for (i = 0, buf[0] = 0; i < slen; i++) {
 493         char tmp[3];
 494
 495         sprintf(tmp, "%02x", (unsigned char)str[i]);
 496         strcat(buf, tmp);
 497     }
 498
 499     return buf;
 500 }
 501
 502 static int verify_host_key(pwm_t *pwm)
 503 {
 504     FILE *fp = fopen(pwm->tcp_conn->known_hosts, "r");
 505     char *buf, *p;
 506
 507     if (!fp)
 508         return 1;
 509
 510     buf = xmalloc(LINE_MAX);
 511
 512     if (!buf)
 513         goto fail;
 514
 515     while ((p = fgets(buf, LINE_MAX, fp))) {
 516         if (*p == '#' || isspace(*p))
 517             continue;
 518
 519         if (p[strlen(p)-1] == '\n')
 520             p[strlen(p)-1] = 0;
 521
 522         if (!strcmp(buf, pwm->tcp_conn->hostkey))
 523             goto done;
 524     }
 525
 526 fail:
 527     if (buf)
 528         xfree(buf);
 529
 530     fclose(fp);
 531     return 1;
 532
 533 done:
 534     xfree(buf);
 535     fclose(fp);
 536     return 0;
 537 }
 538
 539 static gpg_error_t authenticate_ssh(pwm_t *pwm)
 540 {
 541     const char *fp = libssh2_hostkey_hash(pwm->tcp_conn->session,
 542             LIBSSH2_HOSTKEY_HASH_SHA1);
 543     char *userauth;
 544
 545     pwm->tcp_conn->hostkey = to_hex(fp, 20);
 546
 547     if (!pwm->tcp_conn->hostkey)
 548         return gpg_error_from_errno(ENOMEM);
 549
 550     if (pwm->tcp_conn->get_only)
 551         return 0;
 552
 553     if (!fp || verify_host_key(pwm))
 554         return GPG_ERR_CHECKSUM;
 555
 556     userauth = libssh2_userauth_list(pwm->tcp_conn->session,
 557             pwm->tcp_conn->username, strlen(pwm->tcp_conn->username));
 558
 559     if (!userauth || !strstr(userauth, "publickey"))
 560         return GPG_ERR_BAD_PIN_METHOD;
 561
 562     if (libssh2_userauth_publickey_fromfile(pwm->tcp_conn->session,
 563                 pwm->tcp_conn->username, pwm->tcp_conn->identity_pub,
 564                 pwm->tcp_conn->identity, NULL))
 565         return GPG_ERR_BAD_SECKEY;
 566
 567     return 0;
 568 }
 569
 570 static pwm_t *setup_context(pwm_t *pwm, gpg_error_t *rc)
 571 {
 572     assuan_context_t ctx;
 573     struct assuan_io_hooks io_hooks = {read_hook, write_hook};
 574
 575     pwm->tcp_conn->session = libssh2_session_init_ex(_ssh_malloc, _ssh_free,
 576             _ssh_realloc, NULL);
 577
 578     if (!pwm->tcp_conn->session) {
 579         *rc = gpg_error_from_errno(ENOMEM);
 580         goto fail;
 581     }
 582
 583     if (libssh2_session_startup(pwm->tcp_conn->session, pwm->tcp_conn->fd)) {
 584         *rc = GPG_ERR_ASSUAN_SERVER_FAULT;
 585         goto fail;
 586     }
 587
 588     *rc = authenticate_ssh(pwm);
 589
 590     if (*rc)
 591         goto fail;
 592
 593     /* pwmd_get_hostkey(). */
 594     if (pwm->tcp_conn->get_only) {
 595         pwm->result = xstrdup(pwm->tcp_conn->hostkey);
 596
 597         if (!pwm->result) {
 598             *rc = gpg_error_from_errno(ENOMEM);
 599             goto fail;
 600         }
 601
 602         return pwm;
 603     }
 604
 605     pwm->tcp_conn->channel = libssh2_channel_open_session(pwm->tcp_conn->session);
 606
 607     if (!pwm->tcp_conn->channel) {
 608         *rc = GPG_ERR_ASSUAN_SERVER_FAULT;
 609         goto fail;
 610     }
 611
 612     if (libssh2_channel_shell(pwm->tcp_conn->channel)) {
 613         *rc = GPG_ERR_ASSUAN_SERVER_FAULT;
 614         goto fail;
 615     }
 616
 617     assuan_set_io_hooks(&io_hooks);
 618     *rc = assuan_socket_connect_fd(&ctx, pwm->tcp_conn->fd, 0, pwm);
 619
 620     if (*rc)
 621         goto fail;
 622
 623     assuan_set_finish_handler(ctx, _ssh_assuan_deinit);
 624     return _socket_connect_finalize(pwm, ctx);
 625
 626 fail:
 627     if (!pwm->tcp_conn->async)
 628         pwmd_close(pwm);
 629
 630     return NULL;
 631 }
 632
 633 static pwm_t *_do_pwmd_tcp_connect(const char *host, int port,
 634         const char *identity, const char *user, const char *known_hosts,
 635         gpg_error_t *rc, int get)
 636 {
 637     pwm_t *pwm = NULL;
 638     pwmd_tcp_conn_t *conn;
 639
 640     *rc = init_tcp_conn(&conn, host, port, identity, user, known_hosts, get);
 641
 642     if (*rc)
 643         return NULL;
 644
 645     if ((pwm = (pwm_t *)xcalloc(1, sizeof(pwm_t))) == NULL) {
 646         *rc = gpg_error_from_errno(ENOMEM);
 647         goto fail;
 648     }
 649
 650     pwm->tcp_conn = conn;
 651     pwm->tcp_conn->get_only = get;
 652     pwm->cmd = ASYNC_CMD_DNS;
 653     ares_init(&pwm->tcp_conn->chan);
 654     ares_query(pwm->tcp_conn->chan, pwm->tcp_conn->host, ns_c_any, ns_t_any,
 655             dns_resolve_cb, pwm);
 656
 657     /* dns_resolve_cb() may have already been called. */
 658     if (pwm->tcp_conn->rc) {
 659         *rc = pwm->tcp_conn->rc;
 660         goto fail;
 661     }
 662
 663     /*
 664      * Fake a blocking DNS lookup. libcares does a better job than
 665      * getaddrinfo().
 666      */
 667     do {
 668         fd_set rfds, wfds;
 669         int n;
 670         struct timeval tv;
 671
 672         FD_ZERO(&rfds);
 673         FD_ZERO(&wfds);
 674         n = ares_fds(pwm->tcp_conn->chan, &rfds, &wfds);
 675         ares_timeout(pwm->tcp_conn->chan, NULL, &tv);
 676 #ifdef WITH_LIBPTH
 677         n = pth_select(n, &rfds, &wfds, NULL, &tv);
 678 #else
 679         n = select(n, &rfds, &wfds, NULL, &tv);
 680 #endif
 681
 682         if (n == -1) {
 683             *rc = gpg_error_from_syserror();
 684             goto fail;
 685         }
 686         else if (n == 0) {
 687             *rc = GPG_ERR_TIMEOUT;
 688             goto fail;
 689         }
 690
 691         ares_process(pwm->tcp_conn->chan, &rfds, &wfds);
 692
 693         if (pwm->tcp_conn->rc)
 694             break;
 695     } while (pwm->cmd == ASYNC_CMD_DNS);
 696
 697     if (pwm->tcp_conn->rc) {
 698         *rc = pwm->tcp_conn->rc;
 699         goto fail;
 700     }
 701
 702     return setup_context(pwm, rc);
 703
 704 fail:
 705     pwmd_close(pwm);
 706     return NULL;
 707 }
 708
 709 pwm_t *pwmd_tcp_connect(const char *host, int port, const char *identity,
 710         const char *user, const char *known_hosts, gpg_error_t *rc)
 711 {
 712     return _do_pwmd_tcp_connect(host, port, identity, user, known_hosts, rc, 0);
 713 }
 714
 715 /* Must free the result with pwmd_free_result(). */
 716 char *pwmd_get_hostkey(const char *host, int port, gpg_error_t *rc)
 717 {
 718     char *hostkey;
 719     pwm_t *pwm;
 720
 721     pwm = _do_pwmd_tcp_connect(host, port, NULL, NULL, NULL, rc, 1);
 722
 723     if (!pwm)
 724         return NULL;
 725
 726     hostkey = xstrdup(pwm->tcp_conn->hostkey);
 727
 728     if (!hostkey)
 729         *rc = gpg_error_from_errno(ENOMEM);
 730
 731     pwmd_close(pwm);
 732     return hostkey;
 733 }
 734
 735 pwm_t *pwmd_get_hostkey_async(const char *host, int port, gpg_error_t *rc)
 736 {
 737     return _do_pwmd_tcp_connect_async(host, port, NULL, NULL, NULL, rc,
 738             ASYNC_CMD_HOSTKEY);
 739 }
 740 #endif
 741
 742 pwm_t *pwmd_connect(const char *path, gpg_error_t *rc)
 743 {
 744     pwm_t *pwm = NULL;
 745     char *socketpath = NULL;
 746     struct passwd *pw;
 747     assuan_context_t ctx;
 748
 749     if (!path) {
 750         pw = getpwuid(getuid());
 751         socketpath = (char *)xmalloc(strlen(pw->pw_dir) + strlen("/.pwmd/socket") + 1);
 752         sprintf(socketpath, "%s/.pwmd/socket", pw->pw_dir);
 753     }
 754     else
 755         socketpath = xstrdup(path);
 756
 757     *rc = assuan_socket_connect_ext(&ctx, socketpath, -1, 0);
 758     xfree(socketpath);
 759
 760     if (*rc)
 761         return NULL;
 762
 763     if ((pwm = (pwm_t *)xcalloc(1, sizeof(pwm_t))) == NULL) {
 764         *rc = gpg_error_from_syserror();
 765         return NULL;
 766     }
 767
 768     return _socket_connect_finalize(pwm, ctx);
 769 }
 770
 771 gpg_error_t pwmd_pending_line(pwm_t *pwm, char **line, size_t *len)
 772 {
 773     if (!pwm)
 774         return GPG_ERR_INV_ARG;
 775
 776     if (assuan_pending_line(pwm->ctx))
 777         return assuan_read_line(pwm->ctx, line, len);
 778
 779     return GPG_ERR_NO_DATA;
 780 }
 781
 782 void pwmd_close(pwm_t *pwm)
 783 {
 784     if (!pwm)
 785         return;
 786
 787     if (pwm->ctx)
 788         assuan_disconnect(pwm->ctx);
 789
 790     if (pwm->password)
 791         xfree(pwm->password);
 792
 793     if (pwm->title)
 794         xfree(pwm->title);
 795
 796     if (pwm->desc)
 797         xfree(pwm->desc);
 798
 799     if (pwm->prompt)
 800         xfree(pwm->prompt);
 801
 802     if (pwm->pinentry_tty)
 803         xfree(pwm->pinentry_tty);
 804
 805     if (pwm->pinentry_display)
 806         xfree(pwm->pinentry_display);
 807
 808     if (pwm->pinentry_term)
 809         xfree(pwm->pinentry_term);
 810
 811     if (pwm->lcctype)
 812         xfree(pwm->lcctype);
 813
 814     if (pwm->lcmessages)
 815         xfree(pwm->lcmessages);
 816
 817     if (pwm->filename)
 818         xfree(pwm->filename);
 819
 820 #ifdef WITH_TCP
 821     if (pwm->result)
 822         xfree(pwm->result);
 823
 824     if (pwm->tcp_conn)
 825         free_tcp_conn(pwm->tcp_conn);
 826
 827 #endif
 828     xfree(pwm);
 829 }
 830
 831 static int mem_realloc_cb(void *data, const void *buffer, size_t len)
 832 {
 833     membuf_t *mem = (membuf_t *)data;
 834     void *p;
 835
 836     if (!buffer)
 837         return 0;
 838
 839     if ((p = xrealloc(mem->buf, mem->len + len)) == NULL)
 840         return 1;
 841
 842     mem->buf = p;
 843     memcpy((char *)mem->buf + mem->len, buffer, len);
 844     mem->len += len;
 845     return 0;
 846 }
 847
 848 void pwmd_free_result(void *data)
 849 {
 850     xfree(data);
 851 }
 852
 853 static int _inquire_cb(void *data, const char *keyword)
 854 {
 855     pwm_t *pwm = (pwm_t *)data;
 856     gpg_error_t rc = 0;
 857     int flags = fcntl(pwm->fd, F_GETFL);
 858
 859     /* Shouldn't get this far without a callback. */
 860     if (!pwm->inquire_func)
 861         return GPG_ERR_INV_ARG;
 862
 863     /*
 864      * Since the socket file descriptor is probably set to non-blocking, set to
 865      * blocking to prevent GPG_ERR_EAGAIN errors. This should be fixes when
 866      * asynchronous INQUIRE is supported by either libassuan or a later
 867      * libpwmd.
 868      */
 869     fcntl(pwm->fd, F_SETFL, 0);
 870
 871     for (;;) {
 872         char *result = NULL;
 873         size_t len;
 874         gpg_error_t arc;
 875
 876         rc = pwm->inquire_func(pwm->inquire_data, keyword, rc, &result, &len);
 877         rc = gpg_err_code(rc);
 878
 879         if (rc == GPG_ERR_EOF || !rc) {
 880             if (len <= 0 || !result || !*result) {
 881                 rc = 0;
 882                 break;
 883             }
 884
 885             arc = assuan_send_data(pwm->ctx, result, len);
 886
 887             if (rc == GPG_ERR_EOF) {
 888                 rc = arc;
 889                 break;
 890             }
 891
 892             rc = arc;
 893         }
 894         else if (rc)
 895             break;
 896     }
 897
 898     fcntl(pwm->fd, F_SETFL, flags);
 899     return rc;
 900 }
 901
 902 gpg_error_t pwmd_finalize(pwm_t *pwm)
 903 {
 904     if (!pwm || pwm->cmd == ASYNC_CMD_NONE || pwm->state != ASYNC_DONE)
 905         return GPG_ERR_INV_ARG;
 906
 907     pwm->state = ASYNC_INIT;
 908     pwm->cmd = ASYNC_CMD_NONE;
 909
 910 #ifdef WITH_TCP
 911     if (pwm->cmd == ASYNC_CMD_CONNECT || pwm->cmd == ASYNC_CMD_DNS) {
 912         gpg_error_t rc = pwm->tcp_conn->rc;
 913
 914         if (pwm->result)
 915             xfree(pwm->result);
 916
 917         pwm->result = NULL;
 918
 919         /* pwm is no longer a valid handle. */
 920         if (rc)
 921             pwmd_close(pwm);
 922
 923         return 0;
 924     }
 925 #endif
 926
 927     if (pwm->fd < 0)
 928         return GPG_ERR_INV_ARG;
 929
 930     pwm->ntries = 0;
 931 #ifdef WITH_PINENTRY
 932     pwm->is_open_cmd = 0;
 933 #endif
 934     return 0;
 935 }
 936
 937 static gpg_error_t do_nb_command(pwm_t *pwm, const char *cmd, const char *arg)
 938 {
 939     char *buf;
 940     gpg_error_t rc;
 941     size_t len = strlen(cmd) + 2;
 942
 943     len += arg ? strlen(arg) : 0;
 944
 945     if (pwm->state != ASYNC_INIT)
 946         return GPG_ERR_INV_STATE;
 947
 948     buf = (char *)xmalloc(len);
 949
 950     if (!buf) {
 951         rc = gpg_error_from_errno(ENOMEM);
 952         goto fail;
 953     }
 954
 955     snprintf(buf, len, "%s %s", cmd, arg ? arg : "");
 956     rc = assuan_write_line(pwm->ctx, buf);
 957     xfree(buf);
 958
 959     if (!rc)
 960         pwm->state = ASYNC_PROCESS;
 961
 962 fail:
 963     return rc;
 964 }
 965
 966 gpg_error_t pwmd_open_async(pwm_t *pwm, const char *filename)
 967 {
 968     if (!pwm || !filename)
 969         return GPG_ERR_INV_ARG;
 970
 971     /* For pinentry retries. */
 972     if (!pwm->is_open_cmd) {
 973         if (pwm->filename)
 974             xfree(pwm->filename);
 975
 976         pwm->filename = xstrdup(filename);
 977     }
 978
 979     pwm->is_open_cmd = 1;
 980     return do_nb_command(pwm, "OPEN", filename);
 981 }
 982
 983 gpg_error_t pwmd_save_async(pwm_t *pwm)
 984 {
 985     if (!pwm)
 986         return GPG_ERR_INV_ARG;
 987
 988     return do_nb_command(pwm, "SAVE", NULL);
 989 }
 990
 991 static gpg_error_t parse_assuan_line(pwm_t *pwm)
 992 {
 993     gpg_error_t rc;
 994     char *line;
 995     size_t len;
 996
 997     rc = assuan_read_line(pwm->ctx, &line, &len);
 998
 999     if (!rc) {
1000         if (line[0] == 'O' && line[1] == 'K' &&
1001                 (line[2] == 0 || line[2] == ' ')) {
1002             pwm->state = ASYNC_DONE;
1003         }
1004         else if (line[0] == '#') {
1005         }
1006         else if (line[0] == 'S' && (line[1] == 0 || line[1] == ' ')) {
1007             if (pwm->status_func) {
1008                 pwm->status_func(pwm->status_data,
1009                         line[1] == 0 ? line+1 : line+2);
1010             }
1011         }
1012         else if (line[0] == 'E' && line[1] == 'R' && line[2] == 'R' &&
1013                 (line[3] == 0 || line[3] == ' ')) {
1014             line += 4;
1015             rc = atoi(line);
1016             pwm->state = ASYNC_DONE;
1017         }
1018     }
1019
1020     return rc;
1021 }
1022
1023 gpg_error_t pwmd_get_result(pwm_t *pwm, const char **result)
1024 {
1025     if (!pwm || !result)
1026         return GPG_ERR_INV_ARG;
1027
1028     if (pwm->state != ASYNC_DONE)
1029         return GPG_ERR_INV_STATE;
1030
1031     if (!pwm->result)
1032         return GPG_ERR_NO_DATA;
1033
1034     *result = pwm->result;
1035     return 0;
1036 }
1037
1038 pwmd_async_t pwmd_process(pwm_t *pwm, gpg_error_t *rc)
1039 {
1040     fd_set fds;
1041     int n;
1042     struct timeval tv = {0, 0};
1043
1044     *rc = 0;
1045
1046     if (!pwm) {
1047         *rc = GPG_ERR_INV_ARG;
1048         return ASYNC_DONE;
1049     }
1050
1051 #ifdef WITH_TCP
1052     if (pwm->cmd == ASYNC_CMD_DNS) {
1053         fd_set rfds, wfds;
1054
1055         if (pwm->tcp_conn->rc) {
1056             *rc = pwm->tcp_conn->rc;
1057             close(pwm->tcp_conn->fd);
1058             pwm->state = ASYNC_DONE;
1059             return pwm->state;
1060         }
1061
1062         FD_ZERO(&rfds);
1063         FD_ZERO(&wfds);
1064         n = ares_fds(pwm->tcp_conn->chan, &rfds, &wfds);
1065
1066         /* Shouldn't happen. */
1067         if (!n)
1068             return pwm->state;
1069
1070         n = select(n, &rfds, &wfds, NULL, &tv);
1071
1072         if (n > 0)
1073             ares_process(pwm->tcp_conn->chan, &rfds, &wfds);
1074
1075         return pwm->state;
1076     }
1077     else if (pwm->cmd == ASYNC_CMD_CONNECT) {
1078         if (pwm->tcp_conn->rc == GPG_ERR_EINPROGRESS) {
1079             int ret;
1080             socklen_t len = sizeof(int);
1081
1082             FD_ZERO(&fds);
1083             FD_SET(pwm->tcp_conn->fd, &fds);
1084             n = select(pwm->tcp_conn->fd+1, NULL, &fds, NULL, &tv);
1085
1086             if (!n || !FD_ISSET(pwm->tcp_conn->fd, &fds))
1087                 return pwm->state;
1088             else if (n == -1) {
1089                 *rc = gpg_error_from_syserror();
1090                 close(pwm->tcp_conn->fd);
1091                 pwm->state = ASYNC_DONE;
1092                 return pwm->state;
1093             }
1094
1095             ret = getsockopt(pwm->tcp_conn->fd, SOL_SOCKET, SO_ERROR, &n, &len);
1096             if (ret || n) {
1097                 *rc = ret ? gpg_error_from_syserror() : gpg_error_from_errno(n);
1098                 close(pwm->tcp_conn->fd);
1099                 pwm->state = ASYNC_DONE;
1100                 return pwm->state;
1101             }
1102         }
1103         else if (pwm->tcp_conn->rc) {
1104             *rc = pwm->tcp_conn->rc;
1105             close(pwm->tcp_conn->fd);
1106             pwm->state = ASYNC_DONE;
1107             return pwm->state;
1108         }
1109
1110         fcntl(pwm->tcp_conn->fd, F_SETFL, 0);
1111         setup_context(pwm, rc);
1112         pwm->state = ASYNC_DONE;
1113         return pwm->state;
1114     }
1115 #endif
1116
1117     if (pwm->fd < 0) {
1118         *rc = GPG_ERR_INV_ARG;
1119         return ASYNC_DONE;
1120     }
1121     else if (pwm->state == ASYNC_DONE)
1122         return pwm->state;
1123     else if (pwm->state == ASYNC_INIT) {
1124         *rc = GPG_ERR_INV_STATE;
1125         return ASYNC_DONE;
1126     }
1127
1128     FD_ZERO(&fds);
1129     FD_SET(pwm->fd, &fds);
1130 #ifdef WITH_LIBPTH
1131     n = pth_select(pwm->fd+1, &fds, NULL, NULL, &tv);
1132 #else
1133     n = select(pwm->fd+1, &fds, NULL, NULL, &tv);
1134 #endif
1135
1136     if (n > 0) {
1137         if (FD_ISSET(pwm->fd, &fds))
1138             *rc = parse_assuan_line(pwm);
1139     }
1140
1141     while (!*rc && assuan_pending_line(pwm->ctx))
1142         *rc = parse_assuan_line(pwm);
1143
1144     if (pwm->is_open_cmd && gpg_err_code(*rc) == EPWMD_BADKEY &&
1145             ++pwm->ntries < pwm->pinentry_tries) {
1146         pwm->state = ASYNC_INIT;
1147         *rc = pwmd_open_async(pwm, pwm->filename);
1148     }
1149
1150     return pwm->state;
1151 }
1152
1153 static gpg_error_t assuan_command(pwm_t *pwm, assuan_context_t ctx,
1154         char **result, const char *cmd)
1155 {
1156     membuf_t data;
1157     gpg_error_t rc;
1158
1159     data.len = 0;
1160     data.buf = NULL;
1161
1162     rc = assuan_transact(ctx, cmd, mem_realloc_cb, &data, _inquire_cb, pwm,
1163             pwm->status_func, pwm->status_data);
1164
1165     if (rc) {
1166         if (data.buf) {
1167             xfree(data.buf);
1168             data.buf = NULL;
1169         }
1170     }
1171     else {
1172         if (data.buf) {
1173             mem_realloc_cb(&data, "", 1);
1174             *result = (char *)data.buf;
1175         }
1176     }
1177
1178     return gpg_err_code(rc);
1179 }
1180
1181 gpg_error_t pwmd_inquire(pwm_t *pwm, const char *cmd, pwmd_inquire_fn fn,
1182         void *data)
1183 {
1184     if (!pwm || !cmd || !fn)
1185         return GPG_ERR_INV_ARG;
1186
1187     pwm->inquire_func = fn;
1188     pwm->inquire_data = data;
1189     return assuan_command(pwm, pwm->ctx, NULL, cmd);
1190 }
1191
1192 gpg_error_t pwmd_terminate_pinentry(pwm_t *pwm)
1193 {
1194 #ifndef WITH_PINENTRY
1195     return GPG_ERR_NOT_IMPLEMENTED;
1196 #else
1197     pid_t pid = pwm->pid;
1198
1199     pwm->pid = -1;
1200
1201     if (!pwm || pid == -1)
1202         return GPG_ERR_INV_ARG;
1203
1204     if (kill(pid, 0) == 0) {
1205         if (kill(pid, SIGTERM) == -1) {
1206             if (kill(pid, SIGKILL) == -1)
1207                 return gpg_error_from_errno(errno);
1208         }
1209
1210         pwm->pin_error = GPG_ERR_TIMEOUT;
1211     }
1212     else
1213         return gpg_error_from_errno(errno);
1214
1215     return 0;
1216 #endif
1217 }
1218
1219 #ifdef WITH_PINENTRY
1220 static gpg_error_t set_pinentry_strings(pwm_t *pwm, int which)
1221 {
1222     char *buf;
1223     char tmp[ASSUAN_LINELENGTH];
1224     gpg_error_t error;
1225
1226     if (!pwm->title)
1227         pwm->title = xstrdup(N_("LibPWMD"));
1228
1229     if (!pwm->prompt)
1230         pwm->prompt = xstrdup(N_("Passphrase:"));
1231
1232     if (!pwm->desc && !which)
1233         pwm->desc = xstrdup(N_("Enter a passphrase."));
1234
1235     if (which == 1) {
1236         snprintf(tmp, sizeof(tmp), "SETERROR %s", N_("Invalid passphrase, please try again."));
1237         buf = xstrdup(tmp);
1238     }
1239     else if (which == 2) {
1240         snprintf(tmp, sizeof(tmp), "SETERROR %s", N_("Please type the passphrase again for confirmation."));
1241         buf = xstrdup(tmp);
1242     }
1243     else {
1244         buf = (char *)xmalloc(strlen("SETERROR ") + strlen(pwm->desc) + 1);
1245         sprintf(buf, "SETERROR %s", pwm->desc);
1246     }
1247
1248     error = pinentry_command(pwm, NULL, buf);
1249     xfree(buf);
1250
1251     if (error)
1252         return error;
1253
1254     buf = (char *)xmalloc(strlen("SETPROMPT ") + strlen(pwm->prompt) + 1);
1255     sprintf(buf, "SETPROMPT %s", pwm->prompt);
1256     error = pinentry_command(pwm, NULL, buf);
1257     xfree(buf);
1258
1259     if (error)
1260         return error;
1261
1262     buf = (char *)xmalloc(strlen("SETDESC ") + strlen(pwm->title) + 1);
1263     sprintf(buf, "SETDESC %s", pwm->title);
1264     error = pinentry_command(pwm, NULL, buf);
1265     xfree(buf);
1266     return error;
1267 }
1268
1269 static void update_pinentry_settings(pwm_t *pwm)
1270 {
1271     FILE *fp;
1272     char buf[LINE_MAX];
1273     struct passwd *pw = getpwuid(getuid());
1274     char *p;
1275
1276     snprintf(buf, sizeof(buf), "%s/.pwmd/pinentry.conf", pw->pw_dir);
1277
1278     if ((fp = fopen(buf, "r")) == NULL)
1279         return;
1280
1281     while ((p = fgets(buf, sizeof(buf), fp)) != NULL) {
1282         char name[32], val[256];
1283
1284         if (sscanf(p, " %31[a-zA-Z] = %255s", name, val) != 2)
1285             continue;
1286
1287         if (strcasecmp(name, "TTYNAME") == 0) {
1288             xfree(pwm->pinentry_tty);
1289             pwm->pinentry_tty = xstrdup(val);
1290         }
1291         else if (strcasecmp(name, "TTYTYPE") == 0) {
1292             xfree(pwm->pinentry_term);
1293             pwm->pinentry_term = xstrdup(val);
1294         }
1295         else if (strcasecmp(name, "DISPLAY") == 0) {
1296             xfree(pwm->pinentry_display);
1297             pwm->pinentry_display = xstrdup(val);
1298         }
1299         else if (strcasecmp(name, "PATH") == 0) {
1300             xfree(pwm->pinentry_path);
1301             pwm->pinentry_path = xstrdup(val);
1302         }
1303     }
1304
1305     fclose(fp);
1306 }
1307
1308 static gpg_error_t launch_pinentry(pwm_t *pwm)
1309 {
1310     int rc;
1311     assuan_context_t ctx;
1312     int child_list[] = {-1};
1313     char *display = getenv("DISPLAY");
1314     const char *argv[10];
1315     const char **p = argv;
1316     int have_display = 0;
1317     char *tty = NULL;
1318
1319     update_pinentry_settings(pwm);
1320
1321     if (pwm->pinentry_display || display)
1322         have_display = 1;
1323     else {
1324         tty = pwm->pinentry_tty ? pwm->pinentry_tty : ttyname(STDOUT_FILENO);
1325
1326         if (!tty)
1327             return gpg_error_from_errno(errno);
1328     }
1329
1330     if (!have_display && !tty)
1331         return GPG_ERR_ENOTTY;
1332
1333     *p++ = "pinentry";
1334     *p++ = have_display ? "--display" : "--ttyname";
1335     *p++ = have_display ? pwm->pinentry_display ? pwm->pinentry_display : display : tty;
1336
1337     if (pwm->lcctype) {
1338         *p++ = "--lc-ctype";
1339         *p++ = pwm->lcctype;
1340     }
1341
1342     if (pwm->lcmessages) {
1343         *p++ = "--lc-messages";
1344         *p++ = pwm->lcmessages;
1345     }
1346
1347     *p = NULL;
1348
1349     if (!have_display) {
1350         *p++ = "--ttytype";
1351         *p++ = pwm->pinentry_term ? pwm->pinentry_term : getenv("TERM");
1352         *p = NULL;
1353     }
1354
1355     rc = assuan_pipe_connect(&ctx, pwm->pinentry_path ? pwm->pinentry_path : PINENTRY_PATH, argv, child_list);
1356
1357     if (rc)
1358         return rc;
1359
1360     pwm->pid = assuan_get_pid(ctx);
1361     pwm->pctx = ctx;
1362     return set_pinentry_strings(pwm, 0);
1363 }
1364
1365 static gpg_error_t pinentry_command(pwm_t *pwm, char **result, const char *cmd)
1366 {
1367     gpg_error_t n;
1368
1369     if (!pwm->pctx) {
1370         n = launch_pinentry(pwm);
1371
1372         if (n)
1373             return n;
1374     }
1375
1376     return assuan_command(pwm, pwm->pctx, result, cmd);
1377 }
1378
1379 static void pinentry_disconnect(pwm_t *pwm)
1380 {
1381     if (pwm->pctx)
1382         assuan_disconnect(pwm->pctx);
1383
1384     pwm->pctx = NULL;
1385     pwm->pid = -1;
1386 }
1387
1388 /*
1389  * Only called from a child process.
1390  */
1391 static void catchsig(int sig)
1392 {
1393     switch (sig) {
1394         case SIGALRM:
1395             if (gelapsed++ >= gtimeout) {
1396                 global_error = pwmd_terminate_pinentry(gpwm);
1397
1398                 if (!global_error)
1399                     global_error = GPG_ERR_TIMEOUT;
1400
1401                 break;
1402             }
1403
1404             alarm(1);
1405             break;
1406         default:
1407             break;
1408     }
1409 }
1410 #endif
1411
1412 /*
1413  * Borrowed from libassuan.
1414  */
1415 static char *percent_escape(const char *atext)
1416 {
1417     const unsigned char *s;
1418     int len = strlen(atext) * 3 + 1;
1419     char *buf = (char *)xmalloc(len), *p = buf;
1420
1421     if (!buf)
1422         return NULL;
1423
1424     for (s=(const unsigned char *)atext; *s; s++) {
1425         if (*s < ' ') {
1426             sprintf (p, "%%%02X", *s);
1427             p += 3;
1428         }
1429         else
1430             *p++ = *s;
1431     }
1432
1433     *p = 0;
1434     return buf;
1435 }
1436
1437 static gpg_error_t send_command(pwm_t *pwm, char **result, const char *cmd)
1438 {
1439     if (!cmd)
1440         return GPG_ERR_INV_ARG;
1441
1442     return assuan_command(pwm, pwm->ctx, result, cmd);
1443 }
1444
1445 gpg_error_t pwmd_command_ap(pwm_t *pwm, char **result, const char *cmd,
1446         va_list ap)
1447 {
1448     char *buf;
1449     size_t len;
1450     gpg_error_t error;
1451
1452     if (!pwm || !cmd)
1453         return GPG_ERR_INV_ARG;
1454
1455     /*
1456      * C99 allows the dst pointer to be null which will calculate the length
1457      * of the would-be result and return it.
1458      */
1459     len = vsnprintf(NULL, 0, cmd, ap)+1;
1460     buf = (char *)xmalloc(len);
1461     len = vsnprintf(buf, len, cmd, ap);
1462     error = send_command(pwm, result, buf);
1463     xfree(buf);
1464     return error;
1465 }
1466
1467 /*
1468  * Avoid sending the BYE command here. libassuan will close the file
1469  * descriptor and release the assuan context. Use pwmd_close() instead.
1470  */
1471 gpg_error_t pwmd_command(pwm_t *pwm, char **result, const char *cmd, ...)
1472 {
1473     va_list ap;
1474     gpg_error_t error;
1475
1476     if (!pwm || !cmd)
1477         return GPG_ERR_INV_ARG;
1478
1479     *result = NULL;
1480     va_start(ap, cmd);
1481     error = pwmd_command_ap(pwm, result, cmd, ap);
1482     va_end(ap);
1483     return error;
1484 }
1485
1486 #ifdef WITH_PINENTRY
1487 static gpg_error_t do_getpin(pwm_t *pwm, char **result)
1488 {
1489     if (gtimeout) {
1490         signal(SIGALRM, catchsig);
1491         alarm(1);
1492     }
1493
1494     *result = NULL;
1495     return pinentry_command(pwm, result, "GETPIN");
1496 }
1497
1498 static gpg_error_t getpin(pwm_t *pwm, char **result, int *try_n, int which)
1499 {
1500     int pin_try = *try_n;
1501     gpg_error_t error;
1502
1503 getpin_again:
1504     *try_n = pin_try;
1505
1506     if (pin_try == -1) {
1507         error = set_pinentry_strings(pwm, which);
1508
1509         if (error) {
1510             pinentry_disconnect(pwm);
1511             return error;
1512         }
1513     }
1514     else {
1515         if (pwm->pinentry_tries-1 != pin_try) {
1516             error = set_pinentry_strings(pwm, 1);
1517
1518             if (error) {
1519                 pinentry_disconnect(pwm);
1520                 return error;
1521             }
1522         }
1523     }
1524
1525     error = do_getpin(pwm, result);
1526
1527     /*
1528      * Since there was input cancel any timeout setting.
1529      */
1530     alarm(0);
1531
1532     if (error) {
1533         if (error == GPG_ERR_CANCELED)
1534             return GPG_ERR_CANCELED;
1535
1536         if (pin_try != -1 && pin_try--)
1537             goto getpin_again;
1538
1539         if (pwm->pctx)
1540             pinentry_disconnect(pwm);
1541
1542         *try_n = pin_try;
1543         return error;
1544     }
1545
1546     return 0;
1547 }
1548 #endif
1549
1550 gpg_error_t pwmd_open_nb_finalize(pwm_t *pwm, pwmd_nb_status_t *pw)
1551 {
1552     gpg_error_t error;
1553
1554 #ifndef WITH_PINENTRY
1555     return GPG_ERR_NOT_IMPLEMENTED;
1556 #endif
1557
1558     if (!pwm || !pw || !pw->filename[0])
1559         return GPG_ERR_INV_ARG;
1560
1561     close(pw->fd);
1562
1563     if (pw->error) {
1564         error = pw->error;
1565         goto fail;
1566     }
1567
1568     if (pwm->filename)
1569         xfree(pwm->filename);
1570
1571     pwm->filename = xstrdup(pw->filename);
1572     memset(pw, 0, sizeof(pwmd_nb_status_t));
1573     return 0;
1574
1575 fail:
1576     memset(pw, 0, sizeof(pwmd_nb_status_t));
1577     return error;
1578 }
1579
1580 static gpg_error_t do_open_command(pwm_t *pwm, const char *filename, char *password)
1581 {
1582     char buf[ASSUAN_LINELENGTH];
1583     gpg_error_t error;
1584     char *result = NULL;
1585
1586     snprintf(buf, sizeof(buf), "OPEN %s %s", filename, password ? password : "");
1587     error = send_command(pwm, &result, buf);
1588     memset(buf, 0, sizeof(buf));
1589
1590     if (error && result)
1591         xfree(result);
1592
1593     return error;
1594 }
1595
1596 static int do_pwmd_open(pwm_t *pwm, gpg_error_t *error, const char *filename,
1597         int nb, int timeout)
1598 {
1599     char *result = NULL;
1600     char *password = NULL;
1601     char path[PATH_MAX];
1602 #ifdef WITH_PINENTRY
1603     int pin_try;
1604 #endif
1605
1606     if (!pwm || !filename || !*filename) {
1607         *error = GPG_ERR_INV_ARG;
1608         return nb ? -1 : 1;
1609     }
1610
1611 #ifdef WITH_PINENTRY
1612     pin_try = pwm->pinentry_tries - 1;
1613 #endif
1614
1615     /*
1616      * Avoid calling pinentry if the password is cached on the server or if
1617      * this is a new file.
1618      */
1619     *error = pwmd_command(pwm, &result, "GETCONFIG data_directory");
1620
1621     if (*error)
1622         return nb ? -1 : 1;
1623
1624     snprintf(path, sizeof(path), "%s/%s", result, filename);
1625     pwmd_free_result(result);
1626
1627     if (access(path, R_OK) == -1) {
1628         if (errno == ENOENT)
1629             goto gotpassword;
1630     }
1631
1632     *error = pwmd_command(pwm, &result, "ISCACHED %s", filename);
1633
1634     if (*error == EPWMD_CACHE_NOT_FOUND) {
1635         if (pwm->passfunc) {
1636             password = pwm->passfunc(pwm, pwm->passdata);
1637             goto gotpassword;
1638         }
1639
1640 #ifdef WITH_PINENTRY
1641         /*
1642          * Get the password from pinentry.
1643          */
1644         if (pwm->use_pinentry) {
1645             /*
1646              * Nonblocking is wanted. fork() then return a file descriptor
1647              * that the client can use to read() from.
1648              */
1649             if (nb) {
1650                 int p[2];
1651                 pid_t pid;
1652                 pwmd_nb_status_t pw;
1653
1654                 if (pipe(p) == -1) {
1655                     *error = gpg_error_from_syserror();
1656                     return -1;
1657                 }
1658
1659 #ifdef WITH_LIBPTH
1660                 pid = pth_fork();
1661 #else
1662                 pid = fork();
1663 #endif
1664
1665                 switch (pid) {
1666                     case 0:
1667                         close(p[0]);
1668                         strncpy(pw.filename, filename, sizeof(pw.filename));
1669                         pw.filename[sizeof(pw.filename)-1] = 0;
1670                         pw.fd = p[0];
1671
1672                         if (timeout > 0) {
1673                             gpwm = pwm;
1674                             gtimeout = timeout;
1675                             gelapsed = 0;
1676                         }
1677
1678 getpin_nb_again:
1679                         *error = getpin(pwm, &password, &pin_try, 0);
1680
1681                         if (*error) {
1682 getpin_nb_fail:
1683                             if (pwm->pctx)
1684                                 pinentry_disconnect(pwm);
1685
1686                             if (gtimeout && gelapsed >= gtimeout)
1687                                 *error = GPG_ERR_TIMEOUT;
1688
1689                             pw.error = *error;
1690 #ifdef WITH_LIBPTH
1691                             pth_write(p[1], &pw, sizeof(pw));
1692 #else
1693                             write(p[1], &pw, sizeof(pw));
1694 #endif
1695                             close(p[1]);
1696                             _exit(1);
1697                         }
1698
1699                         /*
1700                          * Don't count the time it takes to open the file
1701                          * which may have many iterations.
1702                          */
1703                         signal(SIGALRM, SIG_DFL);
1704                         *error = do_open_command(pwm, filename, password);
1705
1706                         if (timeout)
1707                             signal(SIGALRM, catchsig);
1708
1709                         if (pwm->pctx && *error == EPWMD_BADKEY) {
1710                             if (pin_try-- > 0)
1711                                 goto getpin_nb_again;
1712
1713                             goto getpin_nb_fail;
1714                         }
1715
1716                         pinentry_disconnect(pwm);
1717                         pw.error = 0;
1718 #ifdef WITH_LIBPTH
1719                         pth_write(p[1], &pw, sizeof(pw));
1720 #else
1721                         write(p[1], &pw, sizeof(pw));
1722 #endif
1723                         close(p[1]);
1724                         _exit(0);
1725                         break;
1726                     case -1:
1727                         *error = gpg_error_from_syserror();
1728                         close(p[0]);
1729                         close(p[1]);
1730                         return -1;
1731                     default:
1732                         break;
1733                 }
1734
1735                 close(p[1]);
1736                 *error = 0;
1737                 return p[0];
1738             }
1739         }
1740         else {
1741 #endif
1742             /*
1743              * Not using pinentry and the file was not found
1744              * in the cache.
1745              */
1746             password = pwm->password;
1747 #ifdef WITH_PINENTRY
1748         }
1749 #endif
1750     }
1751     else if (*error)
1752         return nb ? -1 : 1;
1753
1754 gotpassword:
1755     *error = do_open_command(pwm, filename, password);
1756
1757     /*
1758      * Keep the user defined password set with pwmd_setopt(). The password may
1759      * be needed later (pwmd_save()) depending on the pwmd file cache settings.
1760      */
1761     if (!pwm->passfunc && password && password != pwm->password)
1762         xfree(password);
1763
1764 #ifdef WITH_PINENTRY
1765     if (*error == EPWMD_BADKEY) {
1766         if (pin_try-- > 0 && !nb) {
1767             *error = pwmd_command(pwm, &result, "OPTION TITLE=%s",
1768                     N_("Invalid passphrase, please try again."));
1769
1770             if (*error)
1771                 return 1;
1772
1773             goto gotpassword;
1774         }
1775
1776         if (nb)
1777             pinentry_disconnect(pwm);
1778
1779         return nb ? -1 : 1;
1780     }
1781 #endif
1782
1783     if (!*error) {
1784         if (pwm->filename)
1785             xfree(pwm->filename);
1786
1787         pwm->filename = xstrdup(filename);
1788     }
1789
1790     /*
1791      * The file is cached or the file is a new file.
1792      */
1793     if (nb)
1794         return *error ? -1 : -2;
1795
1796     return *error ? 1 : 0;
1797 }
1798
1799 gpg_error_t pwmd_open(pwm_t *pwm, const char *filename)
1800 {
1801     gpg_error_t error;
1802
1803     do_pwmd_open(pwm, &error, filename, 0, 0);
1804     return error;
1805 }
1806
1807 int pwmd_open_nb(pwm_t *pwm, gpg_error_t *error, const char *filename,
1808         int timeout)
1809 {
1810 #ifndef WITH_PINENTRY
1811     *error = GPG_ERR_NOT_IMPLEMENTED;
1812     return -1;
1813 #else
1814     return do_pwmd_open(pwm, error, filename, 1, timeout);
1815 #endif
1816 }
1817
1818 #ifdef WITH_PINENTRY
1819 static gpg_error_t do_save_getpin(pwm_t *pwm, char **password)
1820 {
1821     int confirm = 0;
1822     gpg_error_t error;
1823     char *result = NULL;
1824     int pin_try = -1;
1825
1826 again:
1827     error = getpin(pwm, &result, &pin_try, confirm ? 2 : 0);
1828
1829     if (error) {
1830         if (pwm->pctx)
1831             pinentry_disconnect(pwm);
1832
1833         if (*password)
1834             xfree(*password);
1835
1836         return error;
1837     }
1838
1839     if (!confirm++) {
1840         *password = result;
1841         goto again;
1842     }
1843
1844     if (strcmp(*password, result)) {
1845         xfree(*password);
1846         xfree(result);
1847         pinentry_disconnect(pwm);
1848         error = EPWMD_BADKEY;
1849         return error;
1850     }
1851
1852     xfree(result);
1853     pinentry_disconnect(pwm);
1854     return 0;
1855 }
1856 #endif
1857
1858 static gpg_error_t do_save_command(pwm_t *pwm, char *password)
1859 {
1860     char buf[ASSUAN_LINELENGTH];
1861     gpg_error_t error;
1862     char *result = NULL;
1863
1864     snprintf(buf, sizeof(buf), "SAVE %s", password ? password : "");
1865     error = send_command(pwm, &result, buf);
1866     memset(&buf, 0, sizeof(buf));
1867
1868     if (error && result)
1869         xfree(result);
1870
1871     return error;
1872 }
1873
1874 gpg_error_t pwmd_save_nb_finalize(pwm_t *pwm, pwmd_nb_status_t *pw)
1875 {
1876     gpg_error_t rc;
1877
1878 #ifndef WITH_PINENTRY
1879     return GPG_ERR_NOT_IMPLEMENTED;
1880 #endif
1881
1882     if (!pwm || !pw || !pw->filename[0])
1883         return GPG_ERR_INV_ARG;
1884
1885     close(pw->fd);
1886     rc = pw->error;
1887     memset(pw, 0, sizeof(pwmd_nb_status_t));
1888     return rc;
1889 }
1890
1891 static int do_pwmd_save(pwm_t *pwm, gpg_error_t *error, int nb)
1892 {
1893     char *result = NULL;
1894     char *password = NULL;
1895
1896     if (!pwm) {
1897         *error = GPG_ERR_INV_ARG;
1898         return nb ? -1 : 1;
1899     }
1900
1901     if (pwm->use_pinentry || pwm->passfunc) {
1902         *error = pwmd_command(pwm, &result, "ISCACHED %s", pwm->filename);
1903
1904         if (*error == EPWMD_CACHE_NOT_FOUND) {
1905             if (pwm->passfunc)
1906                 password = (*pwm->passfunc)(pwm, pwm->passdata);
1907 #ifdef WITH_PINENTRY
1908             else if (pwm->use_pinentry) {
1909                 if (nb) {
1910                     int p[2];
1911                     pid_t pid;
1912                     pwmd_nb_status_t pw;
1913
1914                     if (pipe(p) == -1) {
1915                         *error = gpg_error_from_syserror();
1916                         return -1;
1917                     }
1918
1919 #ifdef WITH_LIBPTH
1920                     pid = pth_fork();
1921 #else
1922                     pid = fork();
1923 #endif
1924
1925                     switch (pid) {
1926                         case 0:
1927                             close(p[0]);
1928                             strncpy(pw.filename, pwm->filename, sizeof(pw.filename));
1929                             pw.filename[sizeof(pw.filename)-1] = 0;
1930                             pw.fd = p[0];
1931
1932                             do {
1933                                 password = NULL;
1934                                 *error = do_save_getpin(pwm, &password);
1935                             } while (*error == EPWMD_BADKEY);
1936
1937                             if (*error) {
1938                                 if (pwm->pctx)
1939                                     pinentry_disconnect(pwm);
1940
1941                                 pw.error = *error;
1942 #ifdef WITH_LIBPTH
1943                                 pth_write(p[1], &pw, sizeof(pw));
1944 #else
1945                                 write(p[1], &pw, sizeof(pw));
1946 #endif
1947                                 close(p[1]);
1948                                 _exit(1);
1949                             }
1950
1951                             *error = do_save_command(pwm, password);
1952                             pinentry_disconnect(pwm);
1953                             pw.error = *error;
1954 #ifdef WITH_LIBPTH
1955                             pth_write(p[1], &pw, sizeof(pw));
1956 #else
1957                             write(p[1], &pw, sizeof(pw));
1958 #endif
1959                             close(p[1]);
1960                             _exit(0);
1961                             break;
1962                         case -1:
1963                             *error = gpg_error_from_syserror();
1964                             close(p[0]);
1965                             close(p[1]);
1966                             return -1;
1967                         default:
1968                             break;
1969                     }
1970
1971                     close(p[1]);
1972                     *error = 0;
1973                     return p[0];
1974                 }
1975
1976                 *error = do_save_getpin(pwm, &password);
1977
1978                 if (*error)
1979                     return 1;
1980             }
1981 #endif
1982         }
1983         else {
1984             if (*error)
1985                 return nb ? -1 : 1;
1986         }
1987     }
1988     else
1989         password = pwm->password;
1990
1991     *error = do_save_command(pwm, password);
1992
1993     if (!pwm->passfunc && password && password != pwm->password)
1994         xfree(password);
1995
1996     if (nb)
1997         return *error ? -1 : -2;
1998
1999     return *error ? 1 : 0;
2000 }
2001
2002 int pwmd_save_nb(pwm_t *pwm, gpg_error_t *error)
2003 {
2004 #ifndef WITH_PINENTRY
2005     *error = GPG_ERR_NOT_IMPLEMENTED;
2006     return -1;
2007 #else
2008     return do_pwmd_save(pwm, error, 1);
2009 #endif
2010 }
2011
2012 gpg_error_t pwmd_save(pwm_t *pwm)
2013 {
2014     gpg_error_t error;
2015
2016     do_pwmd_save(pwm, &error, 0);
2017     return error;
2018 }
2019
2020 gpg_error_t pwmd_setopt(pwm_t *pwm, pwmd_option_t opt, ...)
2021 {
2022     va_list ap;
2023     int n = va_arg(ap, int);
2024     char *result;
2025     char *arg1;
2026     gpg_error_t error = 0;
2027
2028     if (!pwm)
2029         return GPG_ERR_INV_ARG;
2030
2031     va_start(ap, opt);
2032
2033     switch (opt) {
2034         case PWMD_OPTION_STATUS_FUNC:
2035             pwm->status_func = va_arg(ap, pwmd_status_fn);
2036             break;
2037         case PWMD_OPTION_STATUS_DATA:
2038             pwm->status_data = va_arg(ap, void *);
2039             break;
2040         case PWMD_OPTION_PASSWORD_FUNC:
2041             pwm->passfunc = va_arg(ap, pwmd_password_fn);
2042             break;
2043         case PWMD_OPTION_PASSWORD_DATA:
2044             pwm->passdata = va_arg(ap, void *);
2045             break;
2046         case PWMD_OPTION_PASSWORD:
2047             arg1 = va_arg(ap, char *);
2048
2049             if (pwm->password)
2050                 xfree(pwm->password);
2051
2052             pwm->password = xstrdup(arg1);
2053             break;
2054         case PWMD_OPTION_PINENTRY:
2055             n = va_arg(ap, int);
2056
2057             if (n != 0 && n != 1) {
2058                 va_end(ap);
2059                 error = GPG_ERR_INV_VALUE;
2060             }
2061             else {
2062                 pwm->use_pinentry = n;
2063                 error = pwmd_command(pwm, &result, "OPTION PINENTRY=%i",
2064                         !pwm->use_pinentry);
2065             }
2066             break;
2067 #ifdef WITH_PINENTRY
2068         case PWMD_OPTION_PINENTRY_TRIES:
2069             n = va_arg(ap, int);
2070
2071             if (n <= 0) {
2072                 va_end(ap);
2073                 error = GPG_ERR_INV_VALUE;
2074             }
2075             else
2076                 pwm->pinentry_tries = n;
2077             break;
2078 #endif
2079         case PWMD_OPTION_PINENTRY_TIMEOUT:
2080             n = va_arg(ap, int);
2081
2082             if (n < 0) {
2083                 va_end(ap);
2084                 error = GPG_ERR_INV_VALUE;
2085             }
2086             else
2087                 pwm->pinentry_timeout = n;
2088
2089             if (!pwm->use_pinentry)
2090                 error = pwmd_command(pwm, &result, "OPTION TIMEOUT=%i",
2091                         pwm->pinentry_timeout);
2092             break;
2093         case PWMD_OPTION_PINENTRY_PATH:
2094             if (pwm->pinentry_path)
2095                 xfree(pwm->pinentry_path);
2096
2097             pwm->pinentry_path = xstrdup(va_arg(ap, char *));
2098
2099             if (!pwm->use_pinentry)
2100                 error = pwmd_command(pwm, &result, "OPTION PATH=%s",
2101                         pwm->pinentry_path);
2102             break;
2103         case PWMD_OPTION_PINENTRY_TTY:
2104             if (pwm->pinentry_tty)
2105                 xfree(pwm->pinentry_tty);
2106
2107             pwm->pinentry_tty = xstrdup(va_arg(ap, char *));
2108
2109             if (!pwm->use_pinentry)
2110                 error = pwmd_command(pwm, &result, "OPTION TTY=%s",
2111                         pwm->pinentry_tty);
2112             break;
2113         case PWMD_OPTION_PINENTRY_DISPLAY:
2114             if (pwm->pinentry_display)
2115                 xfree(pwm->pinentry_display);
2116
2117             pwm->pinentry_display = xstrdup(va_arg(ap, char *));
2118
2119             if (!pwm->use_pinentry)
2120                 error = pwmd_command(pwm, &result, "OPTION DISPLAY=%s",
2121                         pwm->pinentry_display);
2122             break;
2123         case PWMD_OPTION_PINENTRY_TERM:
2124             if (pwm->pinentry_term)
2125                 xfree(pwm->pinentry_term);
2126
2127             pwm->pinentry_term = xstrdup(va_arg(ap, char *));
2128
2129             if (!pwm->use_pinentry)
2130                 error = pwmd_command(pwm, &result, "OPTION TTYTYPE=%s",
2131                         pwm->pinentry_term);
2132             break;
2133         case PWMD_OPTION_PINENTRY_TITLE:
2134             if (pwm->title)
2135                 xfree(pwm->title);
2136
2137             pwm->title = percent_escape(va_arg(ap, char *));
2138
2139             if (!pwm->use_pinentry)
2140                 error = pwmd_command(pwm, &result, "OPTION TITLE=%s",
2141                         pwm->title);
2142             break;
2143         case PWMD_OPTION_PINENTRY_PROMPT:
2144             if (pwm->prompt)
2145                 xfree(pwm->prompt);
2146
2147             pwm->prompt = percent_escape(va_arg(ap, char *));
2148
2149             if (!pwm->use_pinentry)
2150                 error = pwmd_command(pwm, &result, "OPTION PROMPT=%s",
2151                         pwm->prompt);
2152             break;
2153         case PWMD_OPTION_PINENTRY_DESC:
2154             if (pwm->desc)
2155                 xfree(pwm->desc);
2156
2157             pwm->desc = percent_escape(va_arg(ap, char *));
2158
2159             if (!pwm->use_pinentry)
2160                 error = pwmd_command(pwm, &result, "OPTION DESC=%s",
2161                         pwm->desc);
2162             break;
2163         case PWMD_OPTION_PINENTRY_LC_CTYPE:
2164             if (pwm->lcctype)
2165                 xfree(pwm->lcctype);
2166
2167             pwm->lcctype = xstrdup(va_arg(ap, char *));
2168
2169             if (!pwm->use_pinentry)
2170                 error = pwmd_command(pwm, &result, "OPTION LC_CTYPE=%s",
2171                         pwm->lcctype);
2172             break;
2173         case PWMD_OPTION_PINENTRY_LC_MESSAGES:
2174             if (pwm->lcmessages)
2175                 xfree(pwm->lcmessages);
2176
2177             pwm->lcmessages = xstrdup(va_arg(ap, char *));
2178
2179             if (!pwm->use_pinentry)
2180                 error = pwmd_command(pwm, &result, "OPTION LC_MESSAGES=%s",
2181                         pwm->lcmessages);
2182             break;
2183         default:
2184             error = GPG_ERR_NOT_IMPLEMENTED;
2185             break;
2186     }
2187
2188     va_end(ap);
2189     return error;
2190 }
2191
2192 /*
2193  * Prevent requiring assuan.h when setting ctx. The ctx is really an
2194  * assuan_context_t *.
2195  */
2196 gpg_error_t pwmd_assuan_ctx(pwm_t *pwm, void *ctx, int *fd)
2197 {
2198     if (!pwm)
2199         return GPG_ERR_INV_ARG;
2200
2201     ctx = pwm->ctx;
2202     *fd = pwm->fd;
2203     return 0;
2204 }