keydb/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                 }
 236
 237                 if (ret == -1) {
 238                         logthing(LOGTHING_ERROR,
 239                                 "Couldn't open socket to listen on: %s (%d)",
 240                                 strerror(errno),
 241                                 errno);
 242                         close(fd);
 243                         fd = -1;
 244                 }
 245 #ifdef HAVE_SYSTEMD
 246         }
 247 #endif
 248
 249         return fd;
 250 }
 251
 252 static int sock_do(struct onak_dbctx *dbctx, int fd)
 253 {
 254         uint32_t cmd = KEYD_CMD_UNKNOWN;
 255         ssize_t  bytes = 0;
 256         ssize_t  count = 0;
 257         int      ret = 0;
 258         uint64_t keyid = 0;
 259         char     *search = NULL;
 260         struct openpgp_publickey *key = NULL;
 261         struct openpgp_packet_list *packets = NULL;
 262         struct buffer_ctx storebuf;
 263         struct skshash hash;
 264         struct openpgp_fingerprint fingerprint;
 265
 266         /*
 267          * Get the command from the client.
 268          */
 269         bytes = read(fd, &cmd, sizeof(cmd));
 270
 271         logthing(LOGTHING_DEBUG, "Read %d bytes, command: %d", bytes, cmd);
 272
 273         if (bytes != sizeof(cmd)) {
 274                 ret = 1;
 275         }
 276
 277         if (ret == 0) {
 278                 if (cmd < KEYD_CMD_LAST) {
 279                         stats->command_stats[cmd]++;
 280                 } else {
 281                         stats->command_stats[KEYD_CMD_UNKNOWN]++;
 282                 }
 283                 switch (cmd) {
 284                 case KEYD_CMD_VERSION:
 285                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 286                                 ret = 1;
 287                         }
 288                         if (ret == 0) {
 289                                 cmd = sizeof(keyd_version);
 290                                 bytes = write(fd, &cmd, sizeof(cmd));
 291                                 if (bytes != sizeof(cmd)) {
 292                                         ret = 1;
 293                                 }
 294                         }
 295                         if (ret == 0) {
 296                                 bytes = write(fd, &keyd_version,
 297                                         sizeof(keyd_version));
 298                                 if (bytes != sizeof(keyd_version)) {
 299                                         ret = 1;
 300                                 }
 301                         }
 302                         break;
 303                 case KEYD_CMD_GET_ID:
 304                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 305                                 ret = 1;
 306                         }
 307                         if (ret == 0) {
 308                                 bytes = read(fd, &keyid, sizeof(keyid));
 309                                 if (bytes != sizeof(keyid)) {
 310                                         ret = 1;
 311                                 }
 312                         }
 313                         if (ret == 0) {
 314                                 logthing(LOGTHING_INFO,
 315                                                 "Fetching 0x%" PRIX64
 316                                                 ", result: %d",
 317                                                 keyid,
 318                                                 dbctx->fetch_key_id(dbctx,
 319                                                         keyid,
 320                                                         &key, false));
 321                                 if (key != NULL) {
 322                                         keyd_write_key(fd, key);
 323                                         free_publickey(key);
 324                                         key = NULL;
 325                                 } else {
 326                                         if (!keyd_write_size(fd, 0)) {
 327                                                 ret = 1;
 328                                         }
 329                                 }
 330                         }
 331                         break;
 332                 case KEYD_CMD_GET_FP:
 333                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 334                                 ret = 1;
 335                         }
 336                         if (ret == 0) {
 337                                 if ((read(fd, &bytes, 1) != 1) ||
 338                                                 (bytes > MAX_FINGERPRINT_LEN)) {
 339                                         ret = 1;
 340                                 } else {
 341                                         fingerprint.length = bytes;
 342                                         bytes = read(fd, fingerprint.fp,
 343                                                 fingerprint.length);
 344                                         if (bytes != fingerprint.length) {
 345                                                 ret = 1;
 346                                         }
 347                                 }
 348                         }
 349                         if (ret == 0) {
 350                                 logthing(LOGTHING_INFO,
 351                                                 "Fetching by fingerprint"
 352                                                 ", result: %d",
 353                                                 dbctx->fetch_key_fp(dbctx,
 354                                                         &fingerprint,
 355                                                         &key, false));
 356                                 if (key != NULL) {
 357                                         keyd_write_key(fd, key);
 358                                         free_publickey(key);
 359                                         key = NULL;
 360                                 } else {
 361                                         if (!keyd_write_size(fd, 0)) {
 362                                                 ret = 1;
 363                                         }
 364                                 }
 365                         }
 366                         break;
 367
 368                 case KEYD_CMD_GET_TEXT:
 369                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 370                                 ret = 1;
 371                         }
 372                         if (ret == 0) {
 373                                 bytes = read(fd, &count, sizeof(count));
 374                                 if (bytes != sizeof(count)) {
 375                                         ret = 1;
 376                                 }
 377                         }
 378                         if (ret == 0) {
 379                                 search = malloc(count+1);
 380                                 bytes = read(fd, search, count);
 381                                 if (bytes != count) {
 382                                         ret = 1;
 383                                         free(search);
 384                                         break;
 385                                 }
 386                                 search[count] = 0;
 387                                 logthing(LOGTHING_INFO,
 388                                                 "Fetching %s, result: %d",
 389                                                 search,
 390                                                 dbctx->fetch_key_text(dbctx,
 391                                                         search, &key));
 392                                 if (key != NULL) {
 393                                         keyd_write_key(fd, key);
 394                                         free_publickey(key);
 395                                         key = NULL;
 396                                 } else {
 397                                         if (!keyd_write_size(fd, 0)) {
 398                                                 ret = 1;
 399                                         }
 400                                 }
 401                                 free(search);
 402                         }
 403                         break;
 404                 case KEYD_CMD_STORE:
 405                 case KEYD_CMD_UPDATE:
 406                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 407                                 ret = 1;
 408                         }
 409                         if (ret == 0) {
 410                                 bytes = read(fd, &storebuf.size,
 411                                         sizeof(storebuf.size));
 412                                 logthing(LOGTHING_TRACE, "Reading %d bytes.",
 413                                         storebuf.size);
 414                                 if (bytes != sizeof(storebuf.size)) {
 415                                         ret = 1;
 416                                 }
 417                         }
 418                         if (ret == 0 && storebuf.size > 0) {
 419                                 storebuf.buffer = malloc(storebuf.size);
 420                                 storebuf.offset = 0;
 421                                 bytes = count = 0;
 422                                 while (bytes >= 0 && count < storebuf.size) {
 423                                         bytes = read(fd,
 424                                                 &storebuf.buffer[count],
 425                                                 storebuf.size - count);
 426                                         logthing(LOGTHING_TRACE,
 427                                                         "Read %d bytes.",
 428                                                         bytes);
 429                                         count += bytes;
 430                                 }
 431                                 read_openpgp_stream(buffer_fetchchar,
 432                                                 &storebuf,
 433                                                 &packets,
 434                                                 0);
 435                                 parse_keys(packets, &key);
 436                                 dbctx->store_key(dbctx, key, false,
 437                                         (cmd == KEYD_CMD_UPDATE));
 438                                 free_packet_list(packets);
 439                                 packets = NULL;
 440                                 free_publickey(key);
 441                                 key = NULL;
 442                                 free(storebuf.buffer);
 443                                 storebuf.buffer = NULL;
 444                                 storebuf.size = storebuf.offset = 0;
 445                         }
 446                         break;
 447                 case KEYD_CMD_DELETE:
 448                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 449                                 ret = 1;
 450                         }
 451                         if (ret == 0) {
 452                                 bytes = read(fd, &fingerprint,
 453                                                 sizeof(fingerprint));
 454                                 if (bytes != sizeof(fingerprint)) {
 455                                         ret = 1;
 456                                 }
 457                         }
 458                         if (ret == 0) {
 459                                 logthing(LOGTHING_INFO,
 460                                                 "Deleting 0x%" PRIX64
 461                                                 ", result: %d",
 462                                                 keyid,
 463                                                 dbctx->delete_key(dbctx,
 464                                                         &fingerprint, false));
 465                         }
 466                         break;
 467                 case KEYD_CMD_KEYITER:
 468                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 469                                 ret = 1;
 470                         }
 471                         if (ret == 0) {
 472                                 dbctx->iterate_keys(dbctx, iteratefunc,
 473                                         &fd);
 474                                 if (!keyd_write_size(fd, 0)) {
 475                                         ret = 1;
 476                                 }
 477                         }
 478                         break;
 479                 case KEYD_CMD_CLOSE:
 480                         /* We're going to close the FD even if this fails */
 481                         (void) keyd_write_reply(fd, KEYD_REPLY_OK);
 482                         ret = 1;
 483                         break;
 484                 case KEYD_CMD_QUIT:
 485                         /* We're going to quit even if this fails */
 486                         (void) keyd_write_reply(fd, KEYD_REPLY_OK);
 487                         logthing(LOGTHING_NOTICE,
 488                                 "Exiting due to quit request.");
 489                         ret = 1;
 490                         trytocleanup();
 491                         break;
 492                 case KEYD_CMD_STATS:
 493                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 494                                 ret = 1;
 495                         }
 496                         if (ret == 0) {
 497                                 cmd = sizeof(*stats);
 498                                 bytes = write(fd, &cmd, sizeof(cmd));
 499                                 if (bytes != sizeof(cmd)) {
 500                                         ret = 1;
 501                                 }
 502                         }
 503                         if (ret == 0) {
 504                                 bytes = write(fd, stats, sizeof(*stats));
 505                                 if (bytes != sizeof(*stats)) {
 506                                         ret = 1;
 507                                 }
 508                         }
 509                         break;
 510                 case KEYD_CMD_GET_SKSHASH:
 511                         if (!keyd_write_reply(fd, KEYD_REPLY_OK)) {
 512                                 ret = 1;
 513                         }
 514                         if (ret == 0) {
 515                                 bytes = read(fd, hash.hash, sizeof(hash.hash));
 516                                 if (bytes != sizeof(hash.hash)) {
 517                                         ret = 1;
 518                                 }
 519                         }
 520                         if (ret == 0) {
 521                                 logthing(LOGTHING_INFO,
 522                                                 "Fetching by hash"
 523                                                 ", result: %d",
 524                                                 dbctx->fetch_key_skshash(dbctx,
 525                                                         &hash, &key));
 526                                 if (key != NULL) {
 527                                         keyd_write_key(fd, key);
 528                                         free_publickey(key);
 529                                         key = NULL;
 530                                 } else {
 531                                         if (!keyd_write_size(fd, 0)) {
 532                                                 ret = 1;
 533                                         }
 534                                 }
 535                         }
 536                         break;
 537
 538                 default:
 539                         logthing(LOGTHING_ERROR, "Got unknown command: %d",
 540                                         cmd);
 541                         if (!keyd_write_reply(fd, KEYD_REPLY_UNKNOWN_CMD)) {
 542                                 ret = 1;
 543                         }
 544                 }
 545         }
 546
 547         return(ret);
 548 }
 549
 550 static int sock_close(int fd)
 551 {
 552         shutdown(fd, SHUT_RDWR);
 553         return close(fd);
 554 }
 555
 556 static int sock_accept(int fd)
 557 {
 558         struct sockaddr_un sock;
 559         socklen_t          socklen;
 560         int    srv = -1;
 561         int    ret = -1;
 562
 563         socklen = sizeof(sock);
 564         srv = accept(fd, (struct sockaddr *) &sock, &socklen);
 565         if (srv != -1) {
 566                 ret = fcntl(srv, F_SETFD, FD_CLOEXEC);
 567         }
 568
 569         if (ret != -1) {
 570                 stats->connects++;
 571         }
 572
 573         return (srv);
 574 }
 575
 576 static void usage(void)
 577 {
 578         puts("keyd " ONAK_VERSION " - backend key serving daemon for the "
 579                 "onak PGP keyserver.\n");
 580         puts("Usage:\n");
 581         puts("\tkeyd [options]\n");
 582         puts("\tOptions:\n:");
 583         puts("-c <file> - use <file> as the config file");
 584         puts("-f        - run in the foreground");
 585         puts("-h        - show this help text");
 586         exit(EXIT_FAILURE);
 587 }
 588
 589 int main(int argc, char *argv[])
 590 {
 591         int fd = -1, maxfd, i, clients[MAX_CLIENTS];
 592         fd_set rfds = { 0 }; /* Avoid scan-build false report for FD_SET */
 593         char sockname[100];
 594         char *configfile = NULL;
 595         bool foreground = false;
 596         int optchar;
 597         struct onak_dbctx *dbctx;
 598
 599         while ((optchar = getopt(argc, argv, "c:fh")) != -1 ) {
 600                 switch (optchar) {
 601                 case 'c':
 602                         if (configfile != NULL) {
 603                                 free(configfile);
 604                         }
 605                         configfile = strdup(optarg);
 606                         break;
 607                 case 'f':
 608                         foreground = true;
 609                         break;
 610                 case 'h':
 611                 default:
 612                         usage();
 613                         break;
 614                 }
 615         }
 616
 617         readconfig(configfile);
 618         free(configfile);
 619         configfile = NULL;
 620         initlogthing("keyd", config.logfile);
 621         config.use_keyd = false;
 622
 623         if (!foreground) {
 624                 daemonize();
 625         }
 626
 627         catchsignals();
 628         signal(SIGPIPE, SIG_IGN);
 629
 630
 631         stats = calloc(1, sizeof(*stats));
 632         if (!stats) {
 633                 logthing(LOGTHING_ERROR,
 634                         "Couldn't allocate memory for stats structure.");
 635                 exit(EXIT_FAILURE);
 636         }
 637         stats->started = time(NULL);
 638
 639         snprintf(sockname, sizeof(sockname) - 1, "%s/%s",
 640                         config.sock_dir, KEYD_SOCKET);
 641         fd = sock_init(sockname);
 642
 643         if (fd != -1) {
 644                 FD_ZERO(&rfds);
 645                 FD_SET(fd, &rfds);
 646                 maxfd = fd;
 647                 memset(clients, -1, sizeof (clients));
 648
 649                 dbctx = config.dbinit(config.backend, false);
 650
 651                 logthing(LOGTHING_NOTICE, "Accepting connections.");
 652                 while (!cleanup() && select(maxfd + 1, &rfds, NULL, NULL, NULL) != -1) {
 653                         /*
 654                          * Deal with existing clients first; if we're at our
 655                          * connection limit then processing them might free
 656                          * things up and let us accept the next client below.
 657                          */
 658                         for (i = 0; i < MAX_CLIENTS; i++) {
 659                                 if (clients[i] != -1 &&
 660                                                 FD_ISSET(clients[i], &rfds)) {
 661                                         logthing(LOGTHING_DEBUG,
 662                                                 "Handling connection for client %d.", i);
 663                                         if (sock_do(dbctx, clients[i])) {
 664                                                 sock_close(clients[i]);
 665                                                 clients[i] = -1;
 666                                                 logthing(LOGTHING_DEBUG,
 667                                                         "Closed connection for client %d.", i);
 668                                         }
 669                                 }
 670                         }
 671                         /*
 672                          * Check if we have a new incoming connection to accept.
 673                          */
 674                         if (FD_ISSET(fd, &rfds)) {
 675                                 for (i = 0; i < MAX_CLIENTS; i++) {
 676                                         if (clients[i] == -1) {
 677                                                 break;
 678                                         }
 679                                 }
 680                                 if (i < MAX_CLIENTS) {
 681                                         logthing(LOGTHING_INFO,
 682                                                 "Accepted connection %d.", i);
 683                                         clients[i] = sock_accept(fd);
 684                                 }
 685                         }
 686                         FD_ZERO(&rfds);
 687                         FD_SET(fd, &rfds);
 688                         maxfd = fd;
 689                         for (i = 0; i < MAX_CLIENTS; i++) {
 690                                 if (clients[i] != -1) {
 691                                         FD_SET(clients[i], &rfds);
 692                                         maxfd = (maxfd > clients[i]) ?
 693                                                         maxfd : clients[i];
 694                                 }
 695                         }
 696                 }
 697                 dbctx->cleanupdb(dbctx);
 698 #ifdef HAVE_SYSTEMD
 699                 if (!using_socket_activation) {
 700 #endif
 701                         sock_close(fd);
 702                         unlink(sockname);
 703 #ifdef HAVE_SYSTEMD
 704                 }
 705 #endif
 706         }
 707
 708         free(stats);
 709
 710         cleanuplogthing();
 711         cleanupconfig();
 712
 713         return(EXIT_SUCCESS);
 714 }