ucert.c

   1 /*
   2  * Copyright (C) 2018 Daniel Golle <daniel@makrotopia.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 3
   6  * as published by the Free Software Foundation
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #define _GNU_SOURCE
  15
  16 #include <fcntl.h>
  17 #include <dlfcn.h>
  18 #include <errno.h>
  19 #include <stdio.h>
  20 #include <stdbool.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <getopt.h>
  24 #include <stdint.h>
  25 #include <unistd.h>
  26 #include <inttypes.h>
  27 #include <sys/stat.h>
  28 #include <sys/wait.h>
  29
  30 #include <json-c/json.h>
  31 #include <libubox/blob.h>
  32 #include <libubox/utils.h>
  33 #include <libubox/list.h>
  34 #include <libubox/vlist.h>
  35 #include <libubox/blobmsg_json.h>
  36
  37 #include "usign.h"
  38
  39 #define CERT_BUF_LEN 4096
  40
  41 static enum {
  42         CMD_APPEND,
  43         CMD_DUMP,
  44         CMD_ISSUE,
  45         CMD_REVOKE,
  46         CMD_VERIFY,
  47         CMD_NONE,
  48 } cmd = CMD_NONE;
  49
  50 static bool quiet;
  51 #ifndef UCERT_STRIP_MESSAGES
  52 #define DPRINTF(format, ...)                                                                    \
  53         do {                                                                                    \
  54                 if (!quiet)                                                                     \
  55                         fprintf(stderr, "%s(%d): " format, __func__, __LINE__, ## __VA_ARGS__); \
  56         } while (0)
  57 #else
  58 #define DPRINTF(format, ...) do { } while (0)
  59 #endif
  60
  61 /*
  62  * ucert structure
  63  * |               BLOB                    |
  64  * |    SIGNATURE    |       PAYLOAD       |
  65  * |                 |[ BLOBMSG CONTAINER ]|
  66  * |                 |[[T,i,v,e,f,pubkey ]]|
  67  */
  68 enum cert_attr {
  69         CERT_ATTR_SIGNATURE,
  70         CERT_ATTR_PAYLOAD,
  71         CERT_ATTR_MAX
  72 };
  73
  74 static const struct blob_attr_info cert_policy[CERT_ATTR_MAX] = {
  75         [CERT_ATTR_SIGNATURE] = { .type = BLOB_ATTR_BINARY },
  76         [CERT_ATTR_PAYLOAD] = { .type = BLOB_ATTR_NESTED },
  77 };
  78
  79 enum cert_cont_attr {
  80         CERT_CT_ATTR_PAYLOAD,
  81         CERT_CT_ATTR_MAX
  82 };
  83
  84 static const struct blobmsg_policy cert_cont_policy[CERT_CT_ATTR_MAX] = {
  85         [CERT_CT_ATTR_PAYLOAD] = { .name = "ucert", .type = BLOBMSG_TYPE_TABLE },
  86 };
  87
  88 enum cert_payload_attr {
  89         CERT_PL_ATTR_CERTTYPE,
  90         CERT_PL_ATTR_CERTID,
  91         CERT_PL_ATTR_VALIDFROMTIME,
  92         CERT_PL_ATTR_EXPIRETIME,
  93         CERT_PL_ATTR_PUBKEY,
  94         CERT_PL_ATTR_KEY_FINGERPRINT,
  95         CERT_PL_ATTR_MAX
  96 };
  97
  98 enum certtype_id {
  99         CERTTYPE_UNSPEC,
 100         CERTTYPE_AUTH,
 101         CERTTYPE_REVOKE
 102 };
 103
 104 static const struct blobmsg_policy cert_payload_policy[CERT_PL_ATTR_MAX] = {
 105         [CERT_PL_ATTR_CERTTYPE] = { .name = "certtype", .type = BLOBMSG_TYPE_INT32 },
 106         [CERT_PL_ATTR_CERTID] = { .name = "certid", .type = BLOBMSG_TYPE_INT32 },
 107         [CERT_PL_ATTR_VALIDFROMTIME] = { .name = "validfrom", .type = BLOBMSG_TYPE_INT64 },
 108         [CERT_PL_ATTR_EXPIRETIME] = { .name = "expiresat", .type = BLOBMSG_TYPE_INT64 },
 109         [CERT_PL_ATTR_PUBKEY] = { .name = "pubkey", .type = BLOBMSG_TYPE_STRING },
 110         [CERT_PL_ATTR_KEY_FINGERPRINT] = { .name = "fingerprint", .type = BLOBMSG_TYPE_STRING },
 111 };
 112
 113 /* list to store certificate chain at runtime */
 114 struct cert_object {
 115         struct list_head list;
 116         struct blob_attr *cert[CERT_ATTR_MAX];
 117 };
 118
 119 /* write buffer to file */
 120 static bool write_file(const char *filename, void *buf, size_t len, bool append) {
 121         FILE *f;
 122         size_t outlen;
 123
 124         f = fopen(filename, append?"a":"w");
 125         if (!f)
 126                 return false;
 127
 128         outlen = fwrite(buf, 1, len, f);
 129         fclose(f);
 130         return (outlen == len);
 131 }
 132
 133 /* reads a whole file to a buffer - returns -1 on errors and sets errno */
 134 static ssize_t read_file(const char *filename, void *buf, size_t len, size_t minlen) {
 135         FILE *f;
 136         ssize_t ret;
 137
 138         f = fopen(filename, "r");
 139         if (!f)
 140                 return -1;
 141
 142         ret = fread(buf, 1, len, f);
 143
 144         /* Ensure that feof() yields the correct result when the file is exactly
 145          * len bytes long */
 146         fgetc(f);
 147
 148         if (ferror(f)) {
 149                 ret = -1;
 150         } else if (!feof(f)) {
 151                 errno = EOVERFLOW;
 152                 ret = -1;
 153         } else if ((size_t)ret < minlen) {
 154                 errno = EINVAL;
 155                 ret = -1;
 156         }
 157
 158         fclose(f);
 159         return ret;
 160 }
 161
 162 /* load certfile into list */
 163 static int cert_load(const char *certfile, struct list_head *chain) {
 164         struct blob_attr *certtb[CERT_ATTR_MAX];
 165         struct blob_attr *bufpt;
 166         struct cert_object *cobj;
 167         char filebuf[CERT_BUF_LEN];
 168         int ret = 0, pret = 0;
 169         size_t pos = 0;
 170         ssize_t len;
 171
 172         len = read_file(certfile, filebuf, sizeof(filebuf) - 1, 0);
 173         if (len < 0) {
 174                 if (!quiet)
 175                         perror("Unable to load certificate file");
 176                 return 1;
 177         }
 178
 179         bufpt = (struct blob_attr *)filebuf;
 180         do {
 181                 pret = blob_parse_untrusted(bufpt, len, certtb, cert_policy, CERT_ATTR_MAX);
 182                 if (pret <= 0)
 183                         /* no attributes found */
 184                         break;
 185
 186                 if (pos + blob_pad_len(bufpt) > (size_t) len)
 187                         /* blob exceeds filebuffer */
 188                         break;
 189                 else
 190                         pos += blob_pad_len(bufpt);
 191
 192                 if (!certtb[CERT_ATTR_SIGNATURE])
 193                         /* no signature -> drop */
 194                         break;
 195
 196                 cobj = calloc(1, sizeof(*cobj));
 197                 cobj->cert[CERT_ATTR_SIGNATURE] = blob_memdup(certtb[CERT_ATTR_SIGNATURE]);
 198                 if (certtb[CERT_ATTR_PAYLOAD])
 199                         cobj->cert[CERT_ATTR_PAYLOAD] = blob_memdup(certtb[CERT_ATTR_PAYLOAD]);
 200
 201                 list_add_tail(&cobj->list, chain);
 202                 ret += pret;
 203         /* repeat parsing while there is still enough remaining data in buffer */
 204         } while((size_t) len > pos + sizeof(struct blob_attr) && (bufpt = blob_next(bufpt)));
 205
 206         return (ret <= 0);
 207 }
 208
 209 #ifdef UCERT_FULL
 210 /* append signature to certfile */
 211 static int cert_append(const char *certfile, const char *sigfile) {
 212         char filebuf[CERT_BUF_LEN];
 213         struct blob_buf sigbuf = {0};
 214         ssize_t len;
 215         int ret;
 216
 217         len = read_file(sigfile, filebuf, sizeof(filebuf) - 1, 64);
 218         if (len < 0) {
 219                 if (!quiet)
 220                         perror("Unable to load signature file");
 221
 222                 return 1;
 223         }
 224
 225         blob_buf_init(&sigbuf, 0);
 226         blob_put(&sigbuf, CERT_ATTR_SIGNATURE, filebuf, len);
 227         ret = write_file(certfile, sigbuf.head, blob_raw_len(sigbuf.head), true);
 228         blob_buf_free(&sigbuf);
 229         return ret;
 230 }
 231 #endif
 232
 233 /* verify the signature of a single chain element */
 234 static int cert_verify_blob(struct blob_attr *cert[CERT_ATTR_MAX],
 235                        const char *pubkeyfile, const char *pubkeydir) {
 236         int i;
 237         char msgfname[256], sigfname[256];
 238         int ret;
 239         char tmpdir[] = "/tmp/ucert-XXXXXX";
 240
 241         if (mkdtemp(tmpdir) == NULL)
 242                 return errno;
 243
 244         snprintf(msgfname, sizeof(msgfname) - 1, "%s/%s", tmpdir, "payload");
 245         snprintf(sigfname, sizeof(sigfname) - 1, "%s/%s", tmpdir, "payload.sig");
 246
 247         for (i = 0; i < CERT_ATTR_MAX; i++) {
 248                 struct blob_attr *v = cert[i];
 249
 250                 if (!v)
 251                         break;
 252
 253                 switch(cert_policy[i].type) {
 254                 case BLOB_ATTR_BINARY:
 255                         write_file(sigfname, blob_data(v), blob_len(v), false);
 256                         break;
 257                 case BLOB_ATTR_NESTED:
 258                         write_file(msgfname, blob_data(v), blob_len(v), false);
 259                         break;
 260                 }
 261         }
 262
 263         ret = usign_v(msgfname, pubkeyfile, pubkeydir, sigfname, quiet);
 264
 265         unlink(msgfname);
 266         unlink(sigfname);
 267         rmdir(tmpdir);
 268
 269         return ret;
 270 }
 271
 272 /* verify cert chain (and message) */
 273 static int chain_verify(const char *msgfile, const char *pubkeyfile,
 274                         const char *pubkeydir, struct list_head *chain) {
 275         struct cert_object *cobj;
 276         struct blob_attr *containertb[CERT_CT_ATTR_MAX];
 277         struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
 278         char tmpdir[] = "/tmp/ucert-XXXXXX";
 279         char chainedpubkey[256] = {0};
 280         char chainedfp[17] = {0};
 281         char extsigfile[256] = {0};
 282         int ret = 1;
 283         int checkmsg = 0;
 284         struct timeval tv;
 285
 286         if (mkdtemp(tmpdir) == NULL)
 287                 return errno;
 288
 289         if (msgfile)
 290                 checkmsg = -1;
 291
 292         gettimeofday(&tv, NULL);
 293
 294         list_for_each_entry(cobj, chain, list) {
 295                 /* blob has payload, verify that using signature */
 296                 if (cobj->cert[CERT_ATTR_PAYLOAD]) {
 297                         time_t validfrom;
 298                         time_t expiresat;
 299                         uint32_t certtype;
 300
 301                         ret = cert_verify_blob(cobj->cert, chainedpubkey[0]?chainedpubkey:pubkeyfile, pubkeydir);
 302                         if (ret)
 303                                 goto clean_and_return;
 304
 305                         blobmsg_parse(cert_cont_policy,
 306                                       ARRAY_SIZE(cert_cont_policy),
 307                                       containertb,
 308                                       blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
 309                                       blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
 310                         if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
 311                                 ret = 1;
 312                                 DPRINTF("no ucert in signed payload\n");
 313                                 goto clean_and_return;
 314                         }
 315                         blobmsg_parse(cert_payload_policy,
 316                                       ARRAY_SIZE(cert_payload_policy),
 317                                       payloadtb,
 318                                       blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
 319                                       blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
 320
 321                         if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
 322                             !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
 323                             !payloadtb[CERT_PL_ATTR_EXPIRETIME] ||
 324                             !payloadtb[CERT_PL_ATTR_PUBKEY]) {
 325                                 ret = 1;
 326                                 DPRINTF("missing mandatory ucert attributes\n");
 327                                 goto clean_and_return;
 328                         }
 329                         certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
 330                         validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
 331                         expiresat = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_EXPIRETIME]);
 332
 333                         if (certtype != CERTTYPE_AUTH) {
 334                                 ret = 2;
 335                                 DPRINTF("wrong certificate type\n");
 336                                 goto clean_and_return;
 337                         }
 338
 339                         if (tv.tv_sec < validfrom ||
 340                             tv.tv_sec >= expiresat) {
 341                                 ret = 3;
 342                                 DPRINTF("certificate expired\n");
 343                                 goto clean_and_return;
 344                         }
 345
 346                         snprintf(chainedpubkey, sizeof(chainedpubkey) - 1, "%s/%s", tmpdir, "chained-pubkey");
 347                         write_file(chainedpubkey,
 348                                    blobmsg_data(payloadtb[CERT_PL_ATTR_PUBKEY]),
 349                                    blobmsg_data_len(payloadtb[CERT_PL_ATTR_PUBKEY]),
 350                                    false);
 351
 352                         if (usign_f_pubkey(chainedfp, chainedpubkey, quiet)) {
 353                                 DPRINTF("cannot get fingerprint for chained key\n");
 354                                 ret = 2;
 355                                 goto clean_and_return;
 356                         }
 357                         if (pubkeydir && _usign_key_is_revoked(chainedfp, pubkeydir)) {
 358                                 DPRINTF("key %s has been revoked!\n", chainedfp);
 359                                 ret = 4;
 360                                 goto clean_and_return;
 361                         }
 362                 } else {
 363                 /* blob doesn't have payload, verify message using signature */
 364                         if (msgfile) {
 365                                 snprintf(extsigfile, sizeof(extsigfile) - 1, "%s/%s", tmpdir, "ext-sig");
 366                                 write_file(extsigfile,
 367                                            blob_data(cobj->cert[CERT_ATTR_SIGNATURE]),
 368                                            blob_len(cobj->cert[CERT_ATTR_SIGNATURE]),
 369                                            false);
 370                                 checkmsg = ret = usign_v(msgfile,
 371                                               chainedpubkey[0]?chainedpubkey:pubkeyfile,
 372                                               pubkeydir, extsigfile, quiet);
 373                                 unlink(extsigfile);
 374                         } else {
 375                                 DPRINTF("stray trailing signature without anything to verify!\n");
 376                                 ret = 1;
 377                         };
 378                 }
 379         }
 380
 381         if (checkmsg == -1)
 382                 DPRINTF("missing signature to verify message!\n");
 383
 384 clean_and_return:
 385         if (chainedpubkey[0])
 386                 unlink(chainedpubkey);
 387         rmdir(tmpdir);
 388         return ret | checkmsg;
 389 }
 390
 391 #ifdef UCERT_FULL
 392 /* dump single chain element to console */
 393 static void cert_dump_blob(struct blob_attr *cert[CERT_ATTR_MAX]) {
 394         int i;
 395         char *json = NULL;
 396
 397         for (i = 0; i < CERT_ATTR_MAX; i++) {
 398                 struct blob_attr *v = cert[i];
 399
 400                 if (!v)
 401                         continue;
 402
 403                 switch(cert_policy[i].type) {
 404                 case BLOB_ATTR_BINARY:
 405                         printf("signature:\n---\n%s---\n", (char *) blob_data(v));
 406                         break;
 407                 case BLOB_ATTR_NESTED:
 408                         json = blobmsg_format_json_indent(blob_data(v), false, 0);
 409                         if (!json) {
 410                                 DPRINTF("cannot parse payload\n");
 411                                 continue;
 412                         }
 413                         printf("payload:\n---\n%s\n---\n", json);
 414                         free(json);
 415                         break;
 416                 }
 417         }
 418 }
 419
 420 /* dump certfile to console */
 421 static int cert_dump(const char *certfile) {
 422         struct cert_object *cobj;
 423         static LIST_HEAD(certchain);
 424         unsigned int count = 0;
 425
 426         if (cert_load(certfile, &certchain)) {
 427                 DPRINTF("cannot parse cert\n");
 428                 return 1;
 429         }
 430
 431         list_for_each_entry(cobj, &certchain, list) {
 432                 printf("=== CHAIN ELEMENT %02u ===\n", ++count);
 433                 cert_dump_blob(cobj->cert);
 434         }
 435
 436         return 0;
 437 }
 438
 439 /* issue an auth certificate for pubkey */
 440 static int cert_issue(const char *certfile, const char *pubkeyfile, const char *seckeyfile) {
 441         struct blob_buf payloadbuf = {0};
 442         struct blob_buf certbuf = {0};
 443         struct timeval tv;
 444         ssize_t pklen, siglen;
 445         int revoker = 1;
 446         void *c;
 447         char pkb[512];
 448         char sigb[1024];
 449         char fname[256], sfname[256];
 450         char pkfp[17];
 451         char tmpdir[] = "/tmp/ucert-XXXXXX";
 452
 453         pklen = read_file(pubkeyfile, pkb, sizeof(pkb) - 1, 32);
 454         if (pklen < 0) {
 455                 if (!quiet)
 456                         perror("Unable to load public key file");
 457
 458                 return -1;
 459         }
 460
 461         pkb[pklen] = '\0';
 462
 463         if (usign_f_pubkey(pkfp, pubkeyfile, quiet))
 464                 return -1;
 465
 466         gettimeofday(&tv, NULL);
 467
 468         if (mkdtemp(tmpdir) == NULL)
 469                 return errno;
 470
 471         while (revoker >= 0) {
 472                 blob_buf_init(&payloadbuf, 0);
 473                 c = blobmsg_open_table(&payloadbuf, "ucert");
 474                 blobmsg_add_u32(&payloadbuf, "certtype", revoker?CERTTYPE_REVOKE:CERTTYPE_AUTH);
 475                 blobmsg_add_u64(&payloadbuf, "validfrom", tv.tv_sec);
 476                 if (!revoker) {
 477                         blobmsg_add_u64(&payloadbuf, "expiresat", tv.tv_sec + 60 * 60 * 24 * 365);
 478                         blobmsg_add_string(&payloadbuf, "pubkey", pkb);
 479                 } else {
 480                         blobmsg_add_string(&payloadbuf, "fingerprint", pkfp);
 481                 }
 482
 483                 blobmsg_close_table(&payloadbuf, c);
 484
 485                 snprintf(fname, sizeof(fname) - 1, "%s/%s", tmpdir, revoker?"revoker":"payload");
 486                 write_file(fname, blob_data(payloadbuf.head), blob_len(payloadbuf.head), false);
 487
 488                 snprintf(sfname, sizeof(sfname) - 1, "%s/%s", tmpdir, revoker?"revoker.sig":"payload.sig");
 489                 if (usign_s(fname, seckeyfile, sfname, quiet))
 490                         return 1;
 491
 492                 siglen = read_file(sfname, sigb, sizeof(sigb) - 1, 1);
 493                 if (siglen < 0) {
 494                         if (!quiet)
 495                                 perror("Unable to load signature file");
 496
 497                         return 1;
 498                 }
 499
 500                 sigb[siglen] = '\0';
 501
 502                 unlink(fname);
 503                 unlink(sfname);
 504
 505                 blob_buf_init(&certbuf, 0);
 506                 blob_put(&certbuf, CERT_ATTR_SIGNATURE, sigb, siglen);
 507                 blob_put(&certbuf, CERT_ATTR_PAYLOAD, blob_data(payloadbuf.head), blob_len(payloadbuf.head));
 508                 snprintf(fname, sizeof(fname) - 1, "%s%s", certfile, revoker?".revoke":"");
 509                 write_file(fname, certbuf.head, blob_raw_len(certbuf.head), true);
 510                 blob_buf_free(&certbuf);
 511                 blob_buf_free(&payloadbuf);
 512
 513                 revoker--;
 514         }
 515
 516         rmdir(tmpdir);
 517
 518         return 0;
 519 }
 520 #endif
 521
 522 /* process revoker certificate */
 523 static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
 524         static LIST_HEAD(certchain);
 525         struct cert_object *cobj;
 526         struct blob_attr *containertb[CERT_CT_ATTR_MAX];
 527         struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
 528         struct stat st;
 529         struct timeval tv;
 530         time_t validfrom;
 531         enum certtype_id certtype;
 532         char *fingerprint;
 533         char rfname[512];
 534
 535         int ret = -1;
 536
 537         if (cert_load(certfile, &certchain)) {
 538                 DPRINTF("cannot parse cert\n");
 539                 return 1;
 540         }
 541
 542         gettimeofday(&tv, NULL);
 543
 544         list_for_each_entry(cobj, &certchain, list) {
 545                 if (!cobj->cert[CERT_ATTR_PAYLOAD])
 546                         return 2;
 547
 548                 /* blob has payload, verify that using signature */
 549                 ret = cert_verify_blob(cobj->cert, NULL, pubkeydir);
 550                 if (ret)
 551                         return ret;
 552
 553                 blobmsg_parse(cert_cont_policy,
 554                               ARRAY_SIZE(cert_cont_policy),
 555                               containertb,
 556                               blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
 557                               blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
 558                 if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
 559                         DPRINTF("no ucert in signed payload\n");
 560                         return 2;
 561                 }
 562
 563                 blobmsg_parse(cert_payload_policy,
 564                               ARRAY_SIZE(cert_payload_policy),
 565                               payloadtb,
 566                               blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
 567                               blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
 568
 569                 if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
 570                     !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
 571                     !payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]) {
 572                         DPRINTF("missing mandatory ucert attributes\n");
 573                         return 2;
 574                 }
 575
 576                 certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
 577                 validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
 578                 fingerprint = blobmsg_get_string(payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]);
 579
 580                 if (certtype != CERTTYPE_REVOKE) {
 581                         DPRINTF("wrong certificate type\n");
 582                         return 2;
 583                 }
 584
 585                 if (tv.tv_sec < validfrom) {
 586                         return 3;
 587                 }
 588
 589                 snprintf(rfname, sizeof(rfname)-1, "%s/%s", pubkeydir, fingerprint);
 590                 /* check if entry in pubkeydir exists */
 591                 if (stat(rfname, &st) == 0) {
 592                         if (_usign_key_is_revoked(fingerprint, pubkeydir)) {
 593                                 DPRINTF("existing revoker deadlink for key %s\n", fingerprint);
 594                                 continue;
 595                         };
 596
 597                         /* remove any other entry */
 598                         if (unlink(rfname))
 599                                 return -1;
 600                 }
 601
 602                 ret = symlink(".revoked.", rfname);
 603                 if (ret)
 604                         return ret;
 605
 606                 DPRINTF("created revoker deadlink for key %s\n", fingerprint);
 607         };
 608
 609         return ret;
 610 }
 611
 612 /* load and verify certfile (and message) */
 613 static int cert_verify(const char *certfile, const char *pubkeyfile, const char *pubkeydir, const char *msgfile) {
 614         static LIST_HEAD(certchain);
 615
 616         if (cert_load(certfile, &certchain)) {
 617                 DPRINTF("cannot parse cert\n");
 618                 return 1;
 619         }
 620
 621         return chain_verify(msgfile, pubkeyfile, pubkeydir, &certchain);
 622 }
 623
 624 /* output help */
 625 static int usage(const char *cmd)
 626 {
 627 #ifndef UCERT_STRIP_MESSAGES
 628         fprintf(stderr,
 629                 "Usage: %s <command> <options>\n"
 630                 "Commands:\n"
 631 #ifdef UCERT_FULL
 632                 "  -A:                  append signature (needs -c and -x)\n"
 633                 "  -D:                  dump (needs -c)\n"
 634                 "  -I:                  issue cert and revoker (needs -c and -p and -s)\n"
 635 #endif /* UCERT_FULL */
 636                 "  -R:                  process revoker certificate (needs -c and -P)\n"
 637                 "  -V:                  verify (needs -c and -p|-P, may have -m)\n"
 638                 "Options:\n"
 639                 "  -c <file>:           certificate file\n"
 640                 "  -m <file>:           message file (verify only)\n"
 641                 "  -p <file>:           public key file\n"
 642                 "  -P <path>:           public key directory (verify only)\n"
 643                 "  -q:                  quiet (do not print verification result, use return code only)\n"
 644 #ifdef UCERT_FULL
 645                 "  -s <file>:           secret key file (issue only)\n"
 646                 "  -x <file>:           signature file (append only)\n"
 647 #endif /* UCERT_FULL */
 648                 "\n",
 649                 cmd);
 650 #endif /* UCERT_STRIP_MESSAGES */
 651         return 1;
 652 }
 653
 654 /* parse command line options and call functions */
 655 int main(int argc, char *argv[]) {
 656         int ch;
 657         const char *msgfile = NULL;
 658         const char *pubkeyfile = NULL;
 659         const char *pubkeydir = NULL;
 660         const char *certfile = NULL;
 661 #ifdef UCERT_FULL
 662         const char *sigfile = NULL;
 663         const char *seckeyfile = NULL;
 664 #endif
 665
 666         quiet = false;
 667         while ((ch = getopt(argc, argv,
 668                 "RVc:m:p:P:q"
 669 #ifdef UCERT_FULL
 670                 "ADIs:x:"
 671 #endif
 672                )) != -1) {
 673                 switch (ch) {
 674 #ifdef UCERT_FULL
 675                 case 'A':
 676                         if (cmd != CMD_NONE)
 677                                 return usage(argv[0]);
 678                         cmd = CMD_APPEND;
 679                         break;
 680                 case 'D':
 681                         if (cmd != CMD_NONE)
 682                                 return usage(argv[0]);
 683                         cmd = CMD_DUMP;
 684                         break;
 685                 case 'I':
 686                         if (cmd != CMD_NONE)
 687                                 return usage(argv[0]);
 688                         cmd = CMD_ISSUE;
 689                         break;
 690 #endif
 691                 case 'R':
 692                         if (cmd != CMD_NONE)
 693                                 return usage(argv[0]);
 694                         cmd = CMD_REVOKE;
 695                         break;
 696                 case 'V':
 697                         if (cmd != CMD_NONE)
 698                                 return usage(argv[0]);
 699                         cmd = CMD_VERIFY;
 700                         break;
 701                 case 'c':
 702                         if (certfile || cmd == CMD_NONE)
 703                                 return usage(argv[0]);
 704                         certfile = optarg;
 705                         break;
 706                 case 'm':
 707                         if (msgfile || cmd != CMD_VERIFY)
 708                                 return usage(argv[0]);
 709                         msgfile = optarg;
 710                         break;
 711                 case 'p':
 712                         if (pubkeyfile || (cmd != CMD_VERIFY && cmd != CMD_ISSUE) || cmd == CMD_NONE)
 713                                 return usage(argv[0]);
 714                         pubkeyfile = optarg;
 715                         break;
 716                 case 'P':
 717                         if (pubkeydir || (cmd != CMD_VERIFY && cmd != CMD_REVOKE) || cmd == CMD_NONE)
 718                                 return usage(argv[0]);
 719                         pubkeydir = optarg;
 720                         break;
 721                 case 'q':
 722                         if (quiet)
 723                                 return usage(argv[0]);
 724                         quiet = true;
 725                         break;
 726 #ifdef UCERT_FULL
 727                 case 's':
 728                         if (seckeyfile || cmd != CMD_ISSUE || cmd == CMD_NONE)
 729                                 return usage(argv[0]);
 730                         seckeyfile = optarg;
 731                         break;
 732                 case 'x':
 733                         if (sigfile || cmd != CMD_APPEND || cmd == CMD_NONE)
 734                                 return usage(argv[0]);
 735                         sigfile = optarg;
 736                         break;
 737 #endif
 738                 default:
 739                         return usage(argv[0]);
 740                 }
 741         }
 742
 743         switch (cmd) {
 744 #ifdef UCERT_FULL
 745         case CMD_APPEND:
 746                 if (certfile && sigfile)
 747                         return cert_append(certfile, sigfile);
 748                 else
 749                         return usage(argv[0]);
 750         case CMD_DUMP:
 751                 if (certfile)
 752                         return cert_dump(certfile);
 753                 else
 754                         return usage(argv[0]);
 755         case CMD_ISSUE:
 756                 if (certfile && pubkeyfile && seckeyfile)
 757                         return cert_issue(certfile, pubkeyfile, seckeyfile);
 758                 else
 759                         return usage(argv[0]);
 760 #endif
 761         case CMD_REVOKE:
 762                 if (certfile && pubkeydir)
 763                         return cert_process_revoker(certfile, pubkeydir);
 764                 else
 765                         return usage(argv[0]);
 766         case CMD_VERIFY:
 767                 if (certfile && (pubkeyfile || pubkeydir))
 768                         return cert_verify(certfile, pubkeyfile, pubkeydir, msgfile);
 769                 else
 770                         return usage(argv[0]);
 771         default:
 772                 return usage(argv[0]);
 773         }
 774
 775         /* unreachable */
 776         return usage(argv[0]);
 777 }