keyd.c

   1 /*
   2  * keyd.c - key retrieval daemon
   3  *
   4  * Copyright 2004,2011 Jonathan McDowell <noodles@earth.li>
   5  *
   6  * This program is free software: you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program.  If not, see <https://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <errno.h>
  20 #include <fcntl.h>
  21 #include <getopt.h>
  22 #include <inttypes.h>
  23 #include <signal.h>
  24 #include <stdbool.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/select.h>
  29 #include <sys/socket.h>
  30 #include <sys/types.h>
  31 #include <sys/un.h>
  32 #include <time.h>
  33 #include <unistd.h>
  34
  35 #include "build-config.h"
  36
  37 #ifdef HAVE_SYSTEMD
  38 #include <systemd/sd-daemon.h>
  39 #endif
  40
  41 #include "charfuncs.h"
  42 #include "cleanup.h"
  43 #include "keyd.h"
  44 #include "keydb.h"
  45 #include "keyid.h"
  46 #include "keystructs.h"
  47 #include "log.h"
  48 #include "mem.h"
  49 #include "onak-conf.h"
  50 #include "parsekey.h"
  51
  52 /* Maximum number of clients we're prepared to accept at once */
  53 #define MAX_CLIENTS 16
  54
  55 #ifdef HAVE_SYSTEMD
  56 static bool using_socket_activation = false;
  57 #endif
  58
  59 static struct keyd_stats *stats;
  60
  61 static void daemonize(void)
  62 {
  63         pid_t pid;
  64
  65         pid = fork();
  66
  67         if (pid < 0) {
  68                 logthing(LOGTHING_CRITICAL,
  69                         "Failed to fork into background: %d (%s)",
  70                         errno,
  71                         strerror(errno));
  72                 exit(EXIT_FAILURE);
  73         } else if (pid > 0) {
  74                 logthing(LOGTHING_INFO, "Backgrounded as pid %d.", pid);
  75                 exit(EXIT_SUCCESS);
  76         }
  77
  78         if (setsid() == -1) {
  79                 logthing(LOGTHING_CRITICAL,
  80                         "Couldn't set process group leader: %d (%s)",
  81                         errno,
  82                         strerror(errno));
  83                 exit(EXIT_FAILURE);
  84         }
  85
  86         if (!freopen("/dev/null", "r", stdin)) {
  87                 logthing(LOGTHING_CRITICAL,
  88                         "Couldn't reopen stdin to NULL: %d (%s)",
  89                         errno,
  90                         strerror(errno));
  91                 exit(EXIT_FAILURE);
  92         }
  93         if (!freopen("/dev/null", "w", stdout)) {
  94                 logthing(LOGTHING_CRITICAL,
  95                         "Couldn't reopen stdout to NULL: %d (%s)",
  96                         errno,
  97                         strerror(errno));
  98                 exit(EXIT_FAILURE);
  99         }
 100         if (!freopen("/dev/null", "w", stderr)) {
 101                 logthing(LOGTHING_CRITICAL,
 102                         "Couldn't reopen stderr to NULL: %d (%s)",
 103                         errno,
 104                         strerror(errno));
 105                 exit(EXIT_FAILURE);
 106         }
 107
 108         return;
 109 }
 110
 111 static bool keyd_write_key(int fd, struct openpgp_publickey *key)
 112 {
 113         struct openpgp_packet_list *packets = NULL;
 114         struct openpgp_packet_list *list_end = NULL;
 115         struct buffer_ctx           storebuf;
 116         ssize_t written;
 117         bool    ok = true;
 118
 119         storebuf.offset = 0;
 120         storebuf.size = 8192;
 121         storebuf.buffer = malloc(8192);
 122
 123         flatten_publickey(key,
 124                                 &packets,
 125                                 &list_end);
 126         write_openpgp_stream(buffer_putchar,
 127                                 &storebuf,
 128                                 packets);
 129         logthing(LOGTHING_TRACE,
 130                                 "Sending %d bytes.",
 131                                 storebuf.offset);
 132         written = write(fd, &storebuf.offset,
 133                         sizeof(storebuf.offset));
 134         if (written == 0) {
 135                 ok = false;
 136         } else {
 137                 written = write(fd, storebuf.buffer,
 138                         storebuf.offset);
 139                 if (written != storebuf.offset) {
 140                         ok = false;
 141                 }
 142         }
 143
 144         free(storebuf.buffer);
 145         storebuf.buffer = NULL;
 146         storebuf.size = storebuf.offset = 0;
 147         free_packet_list(packets);
 148         packets = list_end = NULL;
 149
 150         return (ok);
 151 }
 152
 153 static bool keyd_write_reply(int fd, enum keyd_reply _reply)
 154 {
 155         uint32_t reply = _reply;
 156         ssize_t written;
 157         bool ok = true;
 158
 159         written = write(fd, &reply, sizeof(reply));
 160         if (written != sizeof(reply)) {
 161                 ok = false;
 162         }
 163
 164         return (ok);
 165 }
 166
 167 static bool keyd_write_size(int fd, size_t size)
 168 {
 169         ssize_t written;
 170         bool ok = true;
 171
 172         written = write(fd, &size, sizeof(size));
 173         if (written != sizeof(size)) {
 174                 ok = false;
 175         }
 176
 177         return (ok);
 178 }
 179
 180 static void iteratefunc(void *ctx, struct openpgp_publickey *key)
 181 {
 182         int      *fd = (int *) ctx;
 183         uint64_t  keyid;
 184
 185         if (key != NULL) {
 186                 get_keyid(key, &keyid);
 187                 logthing(LOGTHING_TRACE,
 188                                 "Iterating over 0x%016" PRIX64 ".",
 189                                 keyid);
 190
 191                 keyd_write_key(*fd, key);
 192         }
 193
 194         return;
 195 }
 196
 197 static int sock_init(const char *sockname)
 198 {
 199         struct sockaddr_un sock;
 200         int                fd = -1;
 201         int                ret = -1;
 202 #ifdef HAVE_SYSTEMD
 203         int                n;
 204
 205         n = sd_listen_fds(0);
 206         if (n > 1) {
 207                 logthing(LOGTHING_ERROR,
 208                         "Too many file descriptors received from systemd.");
 209         } else if (n == 1) {
 210                 fd = SD_LISTEN_FDS_START + 0;
 211                 if (sd_is_socket_unix(fd, SOCK_STREAM, 1, NULL, 0) <= 0) {
 212                         logthing(LOGTHING_ERROR,
 213                                 "systemd passed an invalid socket.");
 214                         fd = -1;
 215                 }
 216                 using_socket_activation = true;
 217         } else {
 218 #endif
 219                 fd = socket(PF_UNIX, SOCK_STREAM, 0);
 220                 if (fd != -1) {
 221                         ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
 222                 }
 223
 224                 if (ret != -1) {
 225                         sock.sun_family = AF_UNIX;
 226                         strncpy(sock.sun_path, sockname,
 227                                         sizeof(sock.sun_path) - 1);
 228                         unlink(sockname);
 229                         ret = bind(fd, (struct sockaddr *) &sock,
 230                                         sizeof(sock));
 231                 }
 232
 233                 if (ret != -1) {
 234                         ret = listen(fd, 5);
 235                         if (ret == -1) {
 236                                 close(fd);
 237                                 fd = -1;
 238                         }
 239                 }
 240 #ifdef HAVE_SYSTEMD
 241         }
 242 #endif
 243
 244         return fd;
 245 }
 246
 247 static int sock_do(struct onak_dbctx *dbctx, int fd)
 248 {
 249         uint32_t cmd = KEYD_CMD_UNKNOWN;
 250         ssize_t  bytes = 0;
 251         ssize_t  count = 0;
 252         int      ret = 0;
 253         uint64_t keyid = 0;
 254         char     *search = NULL;
 255         struct openpgp_publickey *key = NULL;
 256         struct openpgp_packet_list *packets = NULL;
 257         struct buffer_ctx storebuf;
 258         struct skshash hash;
 259         struct openpgp_fingerprint fingerprint;
 260
 261         /*
 262          * Get the command from the client.
 263          */
 264         bytes = read(fd, &cmd, sizeof(cmd));
 265
 266         logthing(LOGTHING_DEBUG, "Read %d bytes, command: %d", bytes, cmd);
 267
 268         if (bytes != sizeof(cmd)) {
 269                 ret = 1;
 270         }
 271
 272         if (ret == 0) {
 273                 if (cmd < KEYD_CMD_LAST) {
 274                         stats->command_stats[cmd]++;
 275                 } else {
 276                         stats->command_stats[KEYD_CMD_UNKNOWN]++;
 277                 }
 278                 switch (cmd) {
 279                 case KEYD_CMD_VERSION:
 280                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 281                                 ret = 1;
 282                         }
 283                         if (ret == 0) {
 284                                 cmd = sizeof(keyd_version);
 285                                 bytes = write(fd, &cmd, sizeof(cmd));
 286                                 if (bytes != sizeof(cmd)) {
 287                                         ret = 1;
 288                                 }
 289                         }
 290                         if (ret == 0) {
 291                                 bytes = write(fd, &keyd_version,
 292                                         sizeof(keyd_version));
 293                                 if (bytes != sizeof(keyd_version)) {
 294                                         ret = 1;
 295                                 }
 296                         }
 297                         break;
 298                 case KEYD_CMD_GET_ID:
 299                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 300                                 ret = 1;
 301                         }
 302                         if (ret == 0) {
 303                                 bytes = read(fd, &keyid, sizeof(keyid));
 304                                 if (bytes != sizeof(keyid)) {
 305                                         ret = 1;
 306                                 }
 307                         }
 308                         if (ret == 0) {
 309                                 logthing(LOGTHING_INFO,
 310                                                 "Fetching 0x%" PRIX64
 311                                                 ", result: %d",
 312                                                 keyid,
 313                                                 dbctx->fetch_key_id(dbctx,
 314                                                         keyid,
 315                                                         &key, false));
 316                                 if (key != NULL) {
 317                                         keyd_write_key(fd, key);
 318                                         free_publickey(key);
 319                                         key = NULL;
 320                                 } else {
 321                                         if (!keyd_write_size(fd, 0)) {
 322                                                 ret = 1;
 323                                         }
 324                                 }
 325                         }
 326                         break;
 327                 case KEYD_CMD_GET_FP:
 328                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 329                                 ret = 1;
 330                         }
 331                         if (ret == 0) {
 332                                 if ((read(fd, &bytes, 1) != 1) ||
 333                                                 (bytes > MAX_FINGERPRINT_LEN)) {
 334                                         ret = 1;
 335                                 } else {
 336                                         fingerprint.length = bytes;
 337                                         bytes = read(fd, fingerprint.fp,
 338                                                 fingerprint.length);
 339                                         if (bytes != fingerprint.length) {
 340                                                 ret = 1;
 341                                         }
 342                                 }
 343                         }
 344                         if (ret == 0) {
 345                                 logthing(LOGTHING_INFO,
 346                                                 "Fetching by fingerprint"
 347                                                 ", result: %d",
 348                                                 dbctx->fetch_key_fp(dbctx,
 349                                                         &fingerprint,
 350                                                         &key, false));
 351                                 if (key != NULL) {
 352                                         keyd_write_key(fd, key);
 353                                         free_publickey(key);
 354                                         key = NULL;
 355                                 } else {
 356                                         if (!keyd_write_size(fd, 0)) {
 357                                                 ret = 1;
 358                                         }
 359                                 }
 360                         }
 361                         break;
 362
 363                 case KEYD_CMD_GET_TEXT:
 364                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 365                                 ret = 1;
 366                         }
 367                         if (ret == 0) {
 368                                 bytes = read(fd, &count, sizeof(count));
 369                                 if (bytes != sizeof(count)) {
 370                                         ret = 1;
 371                                 }
 372                         }
 373                         if (ret == 0) {
 374                                 search = malloc(count+1);
 375                                 bytes = read(fd, search, count);
 376                                 if (bytes != count) {
 377                                         ret = 1;
 378                                         free(search);
 379                                         break;
 380                                 }
 381                                 search[count] = 0;
 382                                 logthing(LOGTHING_INFO,
 383                                                 "Fetching %s, result: %d",
 384                                                 search,
 385                                                 dbctx->fetch_key_text(dbctx,
 386                                                         search, &key));
 387                                 if (key != NULL) {
 388                                         keyd_write_key(fd, key);
 389                                         free_publickey(key);
 390                                         key = NULL;
 391                                 } else {
 392                                         if (!keyd_write_size(fd, 0)) {
 393                                                 ret = 1;
 394                                         }
 395                                 }
 396                                 free(search);
 397                         }
 398                         break;
 399                 case KEYD_CMD_STORE:
 400                 case KEYD_CMD_UPDATE:
 401                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 402                                 ret = 1;
 403                         }
 404                         if (ret == 0) {
 405                                 bytes = read(fd, &storebuf.size,
 406                                         sizeof(storebuf.size));
 407                                 logthing(LOGTHING_TRACE, "Reading %d bytes.",
 408                                         storebuf.size);
 409                                 if (bytes != sizeof(storebuf.size)) {
 410                                         ret = 1;
 411                                 }
 412                         }
 413                         if (ret == 0 && storebuf.size > 0) {
 414                                 storebuf.buffer = malloc(storebuf.size);
 415                                 storebuf.offset = 0;
 416                                 bytes = count = 0;
 417                                 while (bytes >= 0 && count < storebuf.size) {
 418                                         bytes = read(fd,
 419                                                 &storebuf.buffer[count],
 420                                                 storebuf.size - count);
 421                                         logthing(LOGTHING_TRACE,
 422                                                         "Read %d bytes.",
 423                                                         bytes);
 424                                         count += bytes;
 425                                 }
 426                                 read_openpgp_stream(buffer_fetchchar,
 427                                                 &storebuf,
 428                                                 &packets,
 429                                                 0);
 430                                 parse_keys(packets, &key);
 431                                 dbctx->store_key(dbctx, key, false,
 432                                         (cmd == KEYD_CMD_UPDATE));
 433                                 free_packet_list(packets);
 434                                 packets = NULL;
 435                                 free_publickey(key);
 436                                 key = NULL;
 437                                 free(storebuf.buffer);
 438                                 storebuf.buffer = NULL;
 439                                 storebuf.size = storebuf.offset = 0;
 440                         }
 441                         break;
 442                 case KEYD_CMD_DELETE:
 443                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 444                                 ret = 1;
 445                         }
 446                         if (ret == 0) {
 447                                 bytes = read(fd, &fingerprint,
 448                                                 sizeof(fingerprint));
 449                                 if (bytes != sizeof(fingerprint)) {
 450                                         ret = 1;
 451                                 }
 452                         }
 453                         if (ret == 0) {
 454                                 logthing(LOGTHING_INFO,
 455                                                 "Deleting 0x%" PRIX64
 456                                                 ", result: %d",
 457                                                 keyid,
 458                                                 dbctx->delete_key(dbctx,
 459                                                         &fingerprint, false));
 460                         }
 461                         break;
 462                 case KEYD_CMD_KEYITER:
 463                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 464                                 ret = 1;
 465                         }
 466                         if (ret == 0) {
 467                                 dbctx->iterate_keys(dbctx, iteratefunc,
 468                                         &fd);
 469                                 if (!keyd_write_size(fd, 0)) {
 470                                         ret = 1;
 471                                 }
 472                         }
 473                         break;
 474                 case KEYD_CMD_CLOSE:
 475                         /* We're going to close the FD even if this fails */
 476                         (void) keyd_write_reply(fd, KEYD_REPLY_OK);
 477                         ret = 1;
 478                         break;
 479                 case KEYD_CMD_QUIT:
 480                         /* We're going to quit even if this fails */
 481                         (void) keyd_write_reply(fd, KEYD_REPLY_OK);
 482                         logthing(LOGTHING_NOTICE,
 483                                 "Exiting due to quit request.");
 484                         ret = 1;
 485                         trytocleanup();
 486                         break;
 487                 case KEYD_CMD_STATS:
 488                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 489                                 ret = 1;
 490                         }
 491                         if (ret == 0) {
 492                                 cmd = sizeof(*stats);
 493                                 bytes = write(fd, &cmd, sizeof(cmd));
 494                                 if (bytes != sizeof(cmd)) {
 495                                         ret = 1;
 496                                 }
 497                         }
 498                         if (ret == 0) {
 499                                 bytes = write(fd, stats, sizeof(*stats));
 500                                 if (bytes != sizeof(*stats)) {
 501                                         ret = 1;
 502                                 }
 503                         }
 504                         break;
 505                 case KEYD_CMD_GET_SKSHASH:
 506                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 507                                 ret = 1;
 508                         }
 509                         if (ret == 0) {
 510                                 bytes = read(fd, hash.hash, sizeof(hash.hash));
 511                                 if (bytes != sizeof(hash.hash)) {
 512                                         ret = 1;
 513                                 }
 514                         }
 515                         if (ret == 0) {
 516                                 logthing(LOGTHING_INFO,
 517                                                 "Fetching by hash"
 518                                                 ", result: %d",
 519                                                 dbctx->fetch_key_skshash(dbctx,
 520                                                         &hash, &key));
 521                                 if (key != NULL) {
 522                                         keyd_write_key(fd, key);
 523                                         free_publickey(key);
 524                                         key = NULL;
 525                                 } else {
 526                                         if (!keyd_write_size(fd, 0)) {
 527                                                 ret = 1;
 528                                         }
 529                                 }
 530                         }
 531                         break;
 532
 533                 default:
 534                         logthing(LOGTHING_ERROR, "Got unknown command: %d",
 535                                         cmd);
 536                         if (!keyd_write_reply(fd, KEYD_REPLY_UNKNOWN_CMD)) {
 537                                 ret = 1;
 538                         }
 539                 }
 540         }
 541
 542         return(ret);
 543 }
 544
 545 static int sock_close(int fd)
 546 {
 547         shutdown(fd, SHUT_RDWR);
 548         return close(fd);
 549 }
 550
 551 static int sock_accept(int fd)
 552 {
 553         struct sockaddr_un sock;
 554         socklen_t          socklen;
 555         int    srv = -1;
 556         int    ret = -1;
 557
 558         socklen = sizeof(sock);
 559         srv = accept(fd, (struct sockaddr *) &sock, &socklen);
 560         if (srv != -1) {
 561                 ret = fcntl(srv, F_SETFD, FD_CLOEXEC);
 562         }
 563
 564         if (ret != -1) {
 565                 stats->connects++;
 566         }
 567
 568         return (srv);
 569 }
 570
 571 static void usage(void)
 572 {
 573         puts("keyd " ONAK_VERSION " - backend key serving daemon for the "
 574                 "onak PGP keyserver.\n");
 575         puts("Usage:\n");
 576         puts("\tkeyd [options]\n");
 577         puts("\tOptions:\n:");
 578         puts("-c <file> - use <file> as the config file");
 579         puts("-f        - run in the foreground");
 580         puts("-h        - show this help text");
 581         exit(EXIT_FAILURE);
 582 }
 583
 584 int main(int argc, char *argv[])
 585 {
 586         int fd = -1, maxfd, i, clients[MAX_CLIENTS];
 587         fd_set rfds = { 0 }; /* Avoid scan-build false report for FD_SET */
 588         char sockname[100];
 589         char *configfile = NULL;
 590         bool foreground = false;
 591         int optchar;
 592         struct onak_dbctx *dbctx;
 593
 594         while ((optchar = getopt(argc, argv, "c:fh")) != -1 ) {
 595                 switch (optchar) {
 596                 case 'c':
 597                         if (configfile != NULL) {
 598                                 free(configfile);
 599                         }
 600                         configfile = strdup(optarg);
 601                         break;
 602                 case 'f':
 603                         foreground = true;
 604                         break;
 605                 case 'h':
 606                 default:
 607                         usage();
 608                         break;
 609                 }
 610         }
 611
 612         readconfig(configfile);
 613         free(configfile);
 614         configfile = NULL;
 615         initlogthing("keyd", config.logfile);
 616         config.use_keyd = false;
 617
 618         if (!foreground) {
 619                 daemonize();
 620         }
 621
 622         catchsignals();
 623         signal(SIGPIPE, SIG_IGN);
 624
 625
 626         stats = calloc(1, sizeof(*stats));
 627         if (!stats) {
 628                 logthing(LOGTHING_ERROR,
 629                         "Couldn't allocate memory for stats structure.");
 630                 exit(EXIT_FAILURE);
 631         }
 632         stats->started = time(NULL);
 633
 634         snprintf(sockname, sizeof(sockname) - 1, "%s/%s",
 635                         config.sock_dir, KEYD_SOCKET);
 636         fd = sock_init(sockname);
 637
 638         if (fd != -1) {
 639                 FD_ZERO(&rfds);
 640                 FD_SET(fd, &rfds);
 641                 maxfd = fd;
 642                 memset(clients, -1, sizeof (clients));
 643
 644                 dbctx = config.dbinit(config.backend, false);
 645
 646                 logthing(LOGTHING_NOTICE, "Accepting connections.");
 647                 while (!cleanup() && select(maxfd + 1, &rfds, NULL, NULL, NULL) != -1) {
 648                         /*
 649                          * Deal with existing clients first; if we're at our
 650                          * connection limit then processing them might free
 651                          * things up and let us accept the next client below.
 652                          */
 653                         for (i = 0; i < MAX_CLIENTS; i++) {
 654                                 if (clients[i] != -1 &&
 655                                                 FD_ISSET(clients[i], &rfds)) {
 656                                         logthing(LOGTHING_DEBUG,
 657                                                 "Handling connection for client %d.", i);
 658                                         if (sock_do(dbctx, clients[i])) {
 659                                                 sock_close(clients[i]);
 660                                                 clients[i] = -1;
 661                                                 logthing(LOGTHING_DEBUG,
 662                                                         "Closed connection for client %d.", i);
 663                                         }
 664                                 }
 665                         }
 666                         /*
 667                          * Check if we have a new incoming connection to accept.
 668                          */
 669                         if (FD_ISSET(fd, &rfds)) {
 670                                 for (i = 0; i < MAX_CLIENTS; i++) {
 671                                         if (clients[i] == -1) {
 672                                                 break;
 673                                         }
 674                                 }
 675                                 if (i < MAX_CLIENTS) {
 676                                         logthing(LOGTHING_INFO,
 677                                                 "Accepted connection %d.", i);
 678                                         clients[i] = sock_accept(fd);
 679                                 }
 680                         }
 681                         FD_ZERO(&rfds);
 682                         FD_SET(fd, &rfds);
 683                         maxfd = fd;
 684                         for (i = 0; i < MAX_CLIENTS; i++) {
 685                                 if (clients[i] != -1) {
 686                                         FD_SET(clients[i], &rfds);
 687                                         maxfd = (maxfd > clients[i]) ?
 688                                                         maxfd : clients[i];
 689                                 }
 690                         }
 691                 }
 692                 dbctx->cleanupdb(dbctx);
 693 #ifdef HAVE_SYSTEMD
 694                 if (!using_socket_activation) {
 695 #endif
 696                         sock_close(fd);
 697                         unlink(sockname);
 698 #ifdef HAVE_SYSTEMD
 699                 }
 700 #endif
 701         }
 702
 703         free(stats);
 704
 705         cleanuplogthing();
 706         cleanupconfig();
 707
 708         return(EXIT_SUCCESS);
 709 }