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: " format, __func__, ## __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], *end;
 168         int ret = 1;
 169         ssize_t len;
 170
 171         len = read_file(certfile, filebuf, sizeof(filebuf) - 1, 0);
 172         if (len < 0) {
 173                 if (!quiet)
 174                         perror("Unable to load certificate file");
 175                 return 1;
 176         }
 177
 178         bufpt = (struct blob_attr *)filebuf;
 179         end = filebuf + len;
 180
 181         while (true) {
 182                 len = end - (char *)bufpt;
 183                 if (len <= 0)
 184                         break;
 185
 186                 if (blob_parse_untrusted(bufpt, len, certtb, cert_policy, CERT_ATTR_MAX) <= 0)
 187                         /* no attributes found */
 188                         break;
 189
 190                 if (!certtb[CERT_ATTR_SIGNATURE])
 191                         /* no signature -> drop */
 192                         break;
 193
 194                 cobj = calloc(1, sizeof(*cobj));
 195                 cobj->cert[CERT_ATTR_SIGNATURE] = blob_memdup(certtb[CERT_ATTR_SIGNATURE]);
 196                 if (certtb[CERT_ATTR_PAYLOAD])
 197                         cobj->cert[CERT_ATTR_PAYLOAD] = blob_memdup(certtb[CERT_ATTR_PAYLOAD]);
 198
 199                 list_add_tail(&cobj->list, chain);
 200                 ret = 0;
 201
 202                 /* Repeat parsing while there is still enough remaining data in buffer
 203                  *
 204                  * Note that blob_next() is only valid for untrusted data because blob_parse_untrusted()
 205                  * verified that the buffer contains at least one blob, and that it is completely contained
 206                  * in the buffer */
 207                 bufpt = blob_next(bufpt);
 208         }
 209
 210         return ret;
 211 }
 212
 213 #ifdef UCERT_FULL
 214 /* append signature to certfile */
 215 static int cert_append(const char *certfile, const char *sigfile) {
 216         char filebuf[CERT_BUF_LEN];
 217         struct blob_buf sigbuf = {0};
 218         ssize_t len;
 219         int ret;
 220
 221         len = read_file(sigfile, filebuf, sizeof(filebuf) - 1, 64);
 222         if (len < 0) {
 223                 if (!quiet)
 224                         perror("Unable to load signature file");
 225
 226                 return 1;
 227         }
 228
 229         blob_buf_init(&sigbuf, 0);
 230         blob_put(&sigbuf, CERT_ATTR_SIGNATURE, filebuf, len);
 231         ret = write_file(certfile, sigbuf.head, blob_raw_len(sigbuf.head), true);
 232         blob_buf_free(&sigbuf);
 233         return ret;
 234 }
 235 #endif
 236
 237 /* verify the signature of a single chain element */
 238 static int cert_verify_blob(struct blob_attr *cert[CERT_ATTR_MAX],
 239                        const char *pubkeyfile, const char *pubkeydir) {
 240         int i;
 241         char msgfname[256], sigfname[256];
 242         int ret;
 243         char tmpdir[] = "/tmp/ucert-XXXXXX";
 244
 245         if (mkdtemp(tmpdir) == NULL)
 246                 return errno;
 247
 248         snprintf(msgfname, sizeof(msgfname) - 1, "%s/%s", tmpdir, "payload");
 249         snprintf(sigfname, sizeof(sigfname) - 1, "%s/%s", tmpdir, "payload.sig");
 250
 251         for (i = 0; i < CERT_ATTR_MAX; i++) {
 252                 struct blob_attr *v = cert[i];
 253
 254                 if (!v)
 255                         break;
 256
 257                 switch(cert_policy[i].type) {
 258                 case BLOB_ATTR_BINARY:
 259                         write_file(sigfname, blob_data(v), blob_len(v), false);
 260                         break;
 261                 case BLOB_ATTR_NESTED:
 262                         write_file(msgfname, blob_data(v), blob_len(v), false);
 263                         break;
 264                 }
 265         }
 266
 267         ret = usign_v(msgfname, pubkeyfile, pubkeydir, sigfname, quiet);
 268
 269         unlink(msgfname);
 270         unlink(sigfname);
 271         rmdir(tmpdir);
 272
 273         return ret;
 274 }
 275
 276 /* verify cert chain (and message) */
 277 static int chain_verify(const char *msgfile, const char *pubkeyfile,
 278                         const char *pubkeydir, struct list_head *chain) {
 279         struct cert_object *cobj;
 280         struct blob_attr *containertb[CERT_CT_ATTR_MAX];
 281         struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
 282         char tmpdir[] = "/tmp/ucert-XXXXXX";
 283         char chainedpubkey[256] = {0};
 284         char chainedfp[17] = {0};
 285         char extsigfile[256] = {0};
 286         int ret = 1;
 287         int checkmsg = 0;
 288         struct timeval tv;
 289
 290         if (mkdtemp(tmpdir) == NULL)
 291                 return errno;
 292
 293         if (msgfile)
 294                 checkmsg = -1;
 295
 296         gettimeofday(&tv, NULL);
 297
 298         list_for_each_entry(cobj, chain, list) {
 299                 /* blob has payload, verify that using signature */
 300                 if (cobj->cert[CERT_ATTR_PAYLOAD]) {
 301                         time_t validfrom;
 302                         time_t expiresat;
 303                         uint32_t certtype;
 304
 305                         ret = cert_verify_blob(cobj->cert, chainedpubkey[0]?chainedpubkey:pubkeyfile, pubkeydir);
 306                         if (ret)
 307                                 goto clean_and_return;
 308
 309                         blobmsg_parse(cert_cont_policy,
 310                                       ARRAY_SIZE(cert_cont_policy),
 311                                       containertb,
 312                                       blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
 313                                       blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
 314                         if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
 315                                 ret = 1;
 316                                 DPRINTF("no ucert in signed payload\n");
 317                                 goto clean_and_return;
 318                         }
 319                         blobmsg_parse(cert_payload_policy,
 320                                       ARRAY_SIZE(cert_payload_policy),
 321                                       payloadtb,
 322                                       blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
 323                                       blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
 324
 325                         if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
 326                             !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
 327                             !payloadtb[CERT_PL_ATTR_EXPIRETIME] ||
 328                             !payloadtb[CERT_PL_ATTR_PUBKEY]) {
 329                                 ret = 1;
 330                                 DPRINTF("missing mandatory ucert attributes\n");
 331                                 goto clean_and_return;
 332                         }
 333                         certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
 334                         validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
 335                         expiresat = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_EXPIRETIME]);
 336
 337                         if (certtype != CERTTYPE_AUTH) {
 338                                 ret = 2;
 339                                 DPRINTF("wrong certificate type\n");
 340                                 goto clean_and_return;
 341                         }
 342
 343                         if (tv.tv_sec < validfrom ||
 344                             tv.tv_sec >= expiresat) {
 345                                 ret = 3;
 346                                 DPRINTF("certificate expired\n");
 347                                 goto clean_and_return;
 348                         }
 349
 350                         snprintf(chainedpubkey, sizeof(chainedpubkey) - 1, "%s/%s", tmpdir, "chained-pubkey");
 351                         write_file(chainedpubkey,
 352                                    blobmsg_data(payloadtb[CERT_PL_ATTR_PUBKEY]),
 353                                    blobmsg_data_len(payloadtb[CERT_PL_ATTR_PUBKEY]),
 354                                    false);
 355
 356                         if (usign_f_pubkey(chainedfp, chainedpubkey, quiet)) {
 357                                 DPRINTF("cannot get fingerprint for chained key\n");
 358                                 ret = 2;
 359                                 goto clean_and_return;
 360                         }
 361                         if (pubkeydir && _usign_key_is_revoked(chainedfp, pubkeydir)) {
 362                                 DPRINTF("key %s has been revoked!\n", chainedfp);
 363                                 ret = 4;
 364                                 goto clean_and_return;
 365                         }
 366                 } else {
 367                 /* blob doesn't have payload, verify message using signature */
 368                         if (msgfile) {
 369                                 snprintf(extsigfile, sizeof(extsigfile) - 1, "%s/%s", tmpdir, "ext-sig");
 370                                 write_file(extsigfile,
 371                                            blob_data(cobj->cert[CERT_ATTR_SIGNATURE]),
 372                                            blob_len(cobj->cert[CERT_ATTR_SIGNATURE]),
 373                                            false);
 374                                 checkmsg = ret = usign_v(msgfile,
 375                                               chainedpubkey[0]?chainedpubkey:pubkeyfile,
 376                                               pubkeydir, extsigfile, quiet);
 377                                 unlink(extsigfile);
 378                         } else {
 379                                 DPRINTF("stray trailing signature without anything to verify!\n");
 380                                 ret = 1;
 381                         };
 382                 }
 383         }
 384
 385         if (checkmsg == -1)
 386                 DPRINTF("missing signature to verify message!\n");
 387
 388 clean_and_return:
 389         if (chainedpubkey[0])
 390                 unlink(chainedpubkey);
 391         rmdir(tmpdir);
 392         return ret | checkmsg;
 393 }
 394
 395 #ifdef UCERT_FULL
 396 /* dump single chain element to console */
 397 static void cert_dump_blob(struct blob_attr *cert[CERT_ATTR_MAX]) {
 398         int i;
 399         char *json = NULL;
 400
 401         for (i = 0; i < CERT_ATTR_MAX; i++) {
 402                 struct blob_attr *v = cert[i];
 403
 404                 if (!v)
 405                         continue;
 406
 407                 switch(cert_policy[i].type) {
 408                 case BLOB_ATTR_BINARY:
 409                         printf("signature:\n---\n%s---\n", (char *) blob_data(v));
 410                         break;
 411                 case BLOB_ATTR_NESTED:
 412                         json = blobmsg_format_json_indent(blob_data(v), false, 0);
 413                         if (!json) {
 414                                 DPRINTF("cannot parse payload\n");
 415                                 continue;
 416                         }
 417                         printf("payload:\n---\n%s\n---\n", json);
 418                         free(json);
 419                         break;
 420                 }
 421         }
 422 }
 423
 424 /* dump certfile to console */
 425 static int cert_dump(const char *certfile) {
 426         struct cert_object *cobj;
 427         static LIST_HEAD(certchain);
 428         unsigned int count = 0;
 429
 430         if (cert_load(certfile, &certchain)) {
 431                 DPRINTF("cannot parse cert\n");
 432                 return 1;
 433         }
 434
 435         list_for_each_entry(cobj, &certchain, list) {
 436                 printf("=== CHAIN ELEMENT %02u ===\n", ++count);
 437                 cert_dump_blob(cobj->cert);
 438         }
 439
 440         return 0;
 441 }
 442
 443 /* issue an auth certificate for pubkey */
 444 static int cert_issue(const char *certfile, const char *pubkeyfile, const char *seckeyfile) {
 445         struct blob_buf payloadbuf = {0};
 446         struct blob_buf certbuf = {0};
 447         struct timeval tv;
 448         ssize_t pklen, siglen;
 449         int revoker = 1;
 450         void *c;
 451         char pkb[512];
 452         char sigb[1024];
 453         char fname[256], sfname[256];
 454         char pkfp[17];
 455         char tmpdir[] = "/tmp/ucert-XXXXXX";
 456
 457         pklen = read_file(pubkeyfile, pkb, sizeof(pkb) - 1, 32);
 458         if (pklen < 0) {
 459                 if (!quiet)
 460                         perror("Unable to load public key file");
 461
 462                 return -1;
 463         }
 464
 465         pkb[pklen] = '\0';
 466
 467         if (usign_f_pubkey(pkfp, pubkeyfile, quiet))
 468                 return -1;
 469
 470         gettimeofday(&tv, NULL);
 471
 472         if (mkdtemp(tmpdir) == NULL)
 473                 return errno;
 474
 475         while (revoker >= 0) {
 476                 blob_buf_init(&payloadbuf, 0);
 477                 c = blobmsg_open_table(&payloadbuf, "ucert");
 478                 blobmsg_add_u32(&payloadbuf, "certtype", revoker?CERTTYPE_REVOKE:CERTTYPE_AUTH);
 479                 blobmsg_add_u64(&payloadbuf, "validfrom", tv.tv_sec);
 480                 if (!revoker) {
 481                         blobmsg_add_u64(&payloadbuf, "expiresat", tv.tv_sec + 60 * 60 * 24 * 365);
 482                         blobmsg_add_string(&payloadbuf, "pubkey", pkb);
 483                 } else {
 484                         blobmsg_add_string(&payloadbuf, "fingerprint", pkfp);
 485                 }
 486
 487                 blobmsg_close_table(&payloadbuf, c);
 488
 489                 snprintf(fname, sizeof(fname) - 1, "%s/%s", tmpdir, revoker?"revoker":"payload");
 490                 write_file(fname, blob_data(payloadbuf.head), blob_len(payloadbuf.head), false);
 491
 492                 snprintf(sfname, sizeof(sfname) - 1, "%s/%s", tmpdir, revoker?"revoker.sig":"payload.sig");
 493                 if (usign_s(fname, seckeyfile, sfname, quiet))
 494                         return 1;
 495
 496                 siglen = read_file(sfname, sigb, sizeof(sigb) - 1, 1);
 497                 if (siglen < 0) {
 498                         if (!quiet)
 499                                 perror("Unable to load signature file");
 500
 501                         return 1;
 502                 }
 503
 504                 sigb[siglen] = '\0';
 505
 506                 unlink(fname);
 507                 unlink(sfname);
 508
 509                 blob_buf_init(&certbuf, 0);
 510                 blob_put(&certbuf, CERT_ATTR_SIGNATURE, sigb, siglen);
 511                 blob_put(&certbuf, CERT_ATTR_PAYLOAD, blob_data(payloadbuf.head), blob_len(payloadbuf.head));
 512                 snprintf(fname, sizeof(fname) - 1, "%s%s", certfile, revoker?".revoke":"");
 513                 write_file(fname, certbuf.head, blob_raw_len(certbuf.head), true);
 514                 blob_buf_free(&certbuf);
 515                 blob_buf_free(&payloadbuf);
 516
 517                 revoker--;
 518         }
 519
 520         rmdir(tmpdir);
 521
 522         return 0;
 523 }
 524 #endif
 525
 526 /* process revoker certificate */
 527 static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
 528         static LIST_HEAD(certchain);
 529         struct cert_object *cobj;
 530         struct blob_attr *containertb[CERT_CT_ATTR_MAX];
 531         struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
 532         struct stat st;
 533         struct timeval tv;
 534         time_t validfrom;
 535         enum certtype_id certtype;
 536         char *fingerprint;
 537         char rfname[512];
 538
 539         int ret = -1;
 540
 541         if (cert_load(certfile, &certchain)) {
 542                 DPRINTF("cannot parse cert\n");
 543                 return 1;
 544         }
 545
 546         gettimeofday(&tv, NULL);
 547
 548         list_for_each_entry(cobj, &certchain, list) {
 549                 if (!cobj->cert[CERT_ATTR_PAYLOAD])
 550                         return 2;
 551
 552                 /* blob has payload, verify that using signature */
 553                 ret = cert_verify_blob(cobj->cert, NULL, pubkeydir);
 554                 if (ret)
 555                         return ret;
 556
 557                 blobmsg_parse(cert_cont_policy,
 558                               ARRAY_SIZE(cert_cont_policy),
 559                               containertb,
 560                               blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
 561                               blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
 562                 if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
 563                         DPRINTF("no ucert in signed payload\n");
 564                         return 2;
 565                 }
 566
 567                 blobmsg_parse(cert_payload_policy,
 568                               ARRAY_SIZE(cert_payload_policy),
 569                               payloadtb,
 570                               blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
 571                               blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
 572
 573                 if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
 574                     !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
 575                     !payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]) {
 576                         DPRINTF("missing mandatory ucert attributes\n");
 577                         return 2;
 578                 }
 579
 580                 certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
 581                 validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
 582                 fingerprint = blobmsg_get_string(payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]);
 583
 584                 if (certtype != CERTTYPE_REVOKE) {
 585                         DPRINTF("wrong certificate type\n");
 586                         return 2;
 587                 }
 588
 589                 if (tv.tv_sec < validfrom) {
 590                         return 3;
 591                 }
 592
 593                 snprintf(rfname, sizeof(rfname)-1, "%s/%s", pubkeydir, fingerprint);
 594                 /* check if entry in pubkeydir exists */
 595                 if (stat(rfname, &st) == 0) {
 596                         if (_usign_key_is_revoked(fingerprint, pubkeydir)) {
 597                                 DPRINTF("existing revoker deadlink for key %s\n", fingerprint);
 598                                 continue;
 599                         };
 600
 601                         /* remove any other entry */
 602                         if (unlink(rfname))
 603                                 return -1;
 604                 }
 605
 606                 ret = symlink(".revoked.", rfname);
 607                 if (ret)
 608                         return ret;
 609
 610                 DPRINTF("created revoker deadlink for key %s\n", fingerprint);
 611         };
 612
 613         return ret;
 614 }
 615
 616 /* load and verify certfile (and message) */
 617 static int cert_verify(const char *certfile, const char *pubkeyfile, const char *pubkeydir, const char *msgfile) {
 618         static LIST_HEAD(certchain);
 619
 620         if (cert_load(certfile, &certchain)) {
 621                 DPRINTF("cannot parse cert\n");
 622                 return 1;
 623         }
 624
 625         return chain_verify(msgfile, pubkeyfile, pubkeydir, &certchain);
 626 }
 627
 628 /* output help */
 629 static int usage(const char *cmd)
 630 {
 631 #ifndef UCERT_STRIP_MESSAGES
 632         fprintf(stderr,
 633                 "Usage: %s <command> <options>\n"
 634                 "Commands:\n"
 635 #ifdef UCERT_FULL
 636                 "  -A:                  append signature (needs -c and -x)\n"
 637                 "  -D:                  dump (needs -c)\n"
 638                 "  -I:                  issue cert and revoker (needs -c and -p and -s)\n"
 639 #endif /* UCERT_FULL */
 640                 "  -R:                  process revoker certificate (needs -c and -P)\n"
 641                 "  -V:                  verify (needs -c and -p|-P, may have -m)\n"
 642                 "Options:\n"
 643                 "  -c <file>:           certificate file\n"
 644                 "  -m <file>:           message file (verify only)\n"
 645                 "  -p <file>:           public key file\n"
 646                 "  -P <path>:           public key directory (verify only)\n"
 647                 "  -q:                  quiet (do not print verification result, use return code only)\n"
 648 #ifdef UCERT_FULL
 649                 "  -s <file>:           secret key file (issue only)\n"
 650                 "  -x <file>:           signature file (append only)\n"
 651 #endif /* UCERT_FULL */
 652                 "\n",
 653                 cmd);
 654 #endif /* UCERT_STRIP_MESSAGES */
 655         return 1;
 656 }
 657
 658 /* parse command line options and call functions */
 659 int main(int argc, char *argv[]) {
 660         int ch;
 661         const char *msgfile = NULL;
 662         const char *pubkeyfile = NULL;
 663         const char *pubkeydir = NULL;
 664         const char *certfile = NULL;
 665 #ifdef UCERT_FULL
 666         const char *sigfile = NULL;
 667         const char *seckeyfile = NULL;
 668 #endif
 669
 670         quiet = false;
 671         while ((ch = getopt(argc, argv,
 672                 "RVc:m:p:P:q"
 673 #ifdef UCERT_FULL
 674                 "ADIs:x:"
 675 #endif
 676                )) != -1) {
 677                 switch (ch) {
 678 #ifdef UCERT_FULL
 679                 case 'A':
 680                         if (cmd != CMD_NONE)
 681                                 return usage(argv[0]);
 682                         cmd = CMD_APPEND;
 683                         break;
 684                 case 'D':
 685                         if (cmd != CMD_NONE)
 686                                 return usage(argv[0]);
 687                         cmd = CMD_DUMP;
 688                         break;
 689                 case 'I':
 690                         if (cmd != CMD_NONE)
 691                                 return usage(argv[0]);
 692                         cmd = CMD_ISSUE;
 693                         break;
 694 #endif
 695                 case 'R':
 696                         if (cmd != CMD_NONE)
 697                                 return usage(argv[0]);
 698                         cmd = CMD_REVOKE;
 699                         break;
 700                 case 'V':
 701                         if (cmd != CMD_NONE)
 702                                 return usage(argv[0]);
 703                         cmd = CMD_VERIFY;
 704                         break;
 705                 case 'c':
 706                         if (certfile || cmd == CMD_NONE)
 707                                 return usage(argv[0]);
 708                         certfile = optarg;
 709                         break;
 710                 case 'm':
 711                         if (msgfile || cmd != CMD_VERIFY)
 712                                 return usage(argv[0]);
 713                         msgfile = optarg;
 714                         break;
 715                 case 'p':
 716                         if (pubkeyfile || (cmd != CMD_VERIFY && cmd != CMD_ISSUE) || cmd == CMD_NONE)
 717                                 return usage(argv[0]);
 718                         pubkeyfile = optarg;
 719                         break;
 720                 case 'P':
 721                         if (pubkeydir || (cmd != CMD_VERIFY && cmd != CMD_REVOKE) || cmd == CMD_NONE)
 722                                 return usage(argv[0]);
 723                         pubkeydir = optarg;
 724                         break;
 725                 case 'q':
 726                         if (quiet)
 727                                 return usage(argv[0]);
 728                         quiet = true;
 729                         break;
 730 #ifdef UCERT_FULL
 731                 case 's':
 732                         if (seckeyfile || cmd != CMD_ISSUE || cmd == CMD_NONE)
 733                                 return usage(argv[0]);
 734                         seckeyfile = optarg;
 735                         break;
 736                 case 'x':
 737                         if (sigfile || cmd != CMD_APPEND || cmd == CMD_NONE)
 738                                 return usage(argv[0]);
 739                         sigfile = optarg;
 740                         break;
 741 #endif
 742                 default:
 743                         return usage(argv[0]);
 744                 }
 745         }
 746
 747         switch (cmd) {
 748 #ifdef UCERT_FULL
 749         case CMD_APPEND:
 750                 if (certfile && sigfile)
 751                         return cert_append(certfile, sigfile);
 752                 else
 753                         return usage(argv[0]);
 754         case CMD_DUMP:
 755                 if (certfile)
 756                         return cert_dump(certfile);
 757                 else
 758                         return usage(argv[0]);
 759         case CMD_ISSUE:
 760                 if (certfile && pubkeyfile && seckeyfile)
 761                         return cert_issue(certfile, pubkeyfile, seckeyfile);
 762                 else
 763                         return usage(argv[0]);
 764 #endif
 765         case CMD_REVOKE:
 766                 if (certfile && pubkeydir)
 767                         return cert_process_revoker(certfile, pubkeydir);
 768                 else
 769                         return usage(argv[0]);
 770         case CMD_VERIFY:
 771                 if (certfile && (pubkeyfile || pubkeydir))
 772                         return cert_verify(certfile, pubkeyfile, pubkeydir, msgfile);
 773                 else
 774                         return usage(argv[0]);
 775         default:
 776                 return usage(argv[0]);
 777         }
 778
 779         /* unreachable */
 780         return usage(argv[0]);
 781 }