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 <stdio.h>
  19 #include <stdbool.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <getopt.h>
  23 #include <stdint.h>
  24 #include <unistd.h>
  25 #include <inttypes.h>
  26 #include <sys/stat.h>
  27 #include <sys/wait.h>
  28
  29 #include <json-c/json.h>
  30 #include <libubox/blob.h>
  31 #include <libubox/utils.h>
  32 #include <libubox/list.h>
  33 #include <libubox/vlist.h>
  34 #include <libubox/blobmsg_json.h>
  35
  36 #include "usign.h"
  37
  38 #define CERT_BUF_LEN 4096
  39
  40 static enum {
  41         CMD_APPEND,
  42         CMD_DUMP,
  43         CMD_ISSUE,
  44         CMD_REVOKE,
  45         CMD_VERIFY,
  46         CMD_NONE,
  47 } cmd = CMD_NONE;
  48
  49 static bool quiet;
  50
  51 /*
  52  * ucert structure
  53  * |               BLOB                    |
  54  * |    SIGNATURE    |       PAYLOAD       |
  55  * |                 |[ BLOBMSG CONTAINER ]|
  56  * |                 |[[T,i,v,e,f,pubkey ]]|
  57  */
  58 enum cert_attr {
  59         CERT_ATTR_SIGNATURE,
  60         CERT_ATTR_PAYLOAD,
  61         CERT_ATTR_MAX
  62 };
  63
  64 static const struct blob_attr_info cert_policy[CERT_ATTR_MAX] = {
  65         [CERT_ATTR_SIGNATURE] = { .type = BLOB_ATTR_BINARY },
  66         [CERT_ATTR_PAYLOAD] = { .type = BLOB_ATTR_NESTED },
  67 };
  68
  69 enum cert_cont_attr {
  70         CERT_CT_ATTR_PAYLOAD,
  71         CERT_CT_ATTR_MAX
  72 };
  73
  74 static const struct blobmsg_policy cert_cont_policy[CERT_CT_ATTR_MAX] = {
  75         [CERT_CT_ATTR_PAYLOAD] = { .name = "ucert", .type = BLOBMSG_TYPE_TABLE },
  76 };
  77
  78 enum cert_payload_attr {
  79         CERT_PL_ATTR_CERTTYPE,
  80         CERT_PL_ATTR_CERTID,
  81         CERT_PL_ATTR_VALIDFROMTIME,
  82         CERT_PL_ATTR_EXPIRETIME,
  83         CERT_PL_ATTR_PUBKEY,
  84         CERT_PL_ATTR_KEY_FINGERPRINT,
  85         CERT_PL_ATTR_MAX
  86 };
  87
  88 enum certtype_id {
  89         CERTTYPE_UNSPEC,
  90         CERTTYPE_AUTH,
  91         CERTTYPE_REVOKE
  92 };
  93
  94 static const struct blobmsg_policy cert_payload_policy[CERT_PL_ATTR_MAX] = {
  95         [CERT_PL_ATTR_CERTTYPE] = { .name = "certtype", .type = BLOBMSG_TYPE_INT32 },
  96         [CERT_PL_ATTR_CERTID] = { .name = "certid", .type = BLOBMSG_TYPE_INT32 },
  97         [CERT_PL_ATTR_VALIDFROMTIME] = { .name = "validfrom", .type = BLOBMSG_TYPE_INT64 },
  98         [CERT_PL_ATTR_EXPIRETIME] = { .name = "expiresat", .type = BLOBMSG_TYPE_INT64 },
  99         [CERT_PL_ATTR_PUBKEY] = { .name = "pubkey", .type = BLOBMSG_TYPE_STRING },
 100         [CERT_PL_ATTR_KEY_FINGERPRINT] = { .name = "fingerprint", .type = BLOBMSG_TYPE_STRING },
 101 };
 102
 103 /* list to store certificate chain at runtime */
 104 struct cert_object {
 105         struct list_head list;
 106         struct blob_attr *cert[CERT_ATTR_MAX];
 107 };
 108
 109 /* write buffer to file */
 110 static int write_file(const char *filename, void *buf, size_t len, bool append) {
 111         FILE *f;
 112         size_t outlen;
 113
 114         f = fopen(filename, append?"a":"w");
 115         if (!f)
 116                 return 1;
 117
 118         outlen = fwrite(buf, 1, len, f);
 119         fclose(f);
 120         return (outlen == len);
 121 }
 122
 123 /* load certfile into list */
 124 static int cert_load(const char *certfile, struct list_head *chain) {
 125         FILE *f;
 126         struct blob_attr *certtb[CERT_ATTR_MAX];
 127         struct blob_attr *bufpt;
 128         struct cert_object *cobj;
 129         char filebuf[CERT_BUF_LEN];
 130         int ret = 0, pret = 0;
 131         int len, pos = 0;
 132
 133         f = fopen(certfile, "r");
 134         if (!f)
 135                 return 1;
 136
 137         len = fread(&filebuf, 1, CERT_BUF_LEN - 1, f);
 138         if (len < 64)
 139                 return 1;
 140
 141         ret = ferror(f) || !feof(f);
 142         fclose(f);
 143         if (ret)
 144                 return 1;
 145
 146         bufpt = (struct blob_attr *)filebuf;
 147         do {
 148                 pret = blob_parse(bufpt, certtb, cert_policy, CERT_ATTR_MAX);
 149                 if (pret <= 0)
 150                         /* no attributes found */
 151                         break;
 152
 153                 if (pos + blob_pad_len(bufpt) > len)
 154                         /* blob exceeds filebuffer */
 155                         break;
 156                 else
 157                         pos += blob_pad_len(bufpt);
 158
 159                 if (!certtb[CERT_ATTR_SIGNATURE])
 160                         /* no signature -> drop */
 161                         break;
 162
 163                 cobj = calloc(1, sizeof(*cobj));
 164                 cobj->cert[CERT_ATTR_SIGNATURE] = blob_memdup(certtb[CERT_ATTR_SIGNATURE]);
 165                 if (certtb[CERT_ATTR_PAYLOAD])
 166                         cobj->cert[CERT_ATTR_PAYLOAD] = blob_memdup(certtb[CERT_ATTR_PAYLOAD]);
 167
 168                 list_add_tail(&cobj->list, chain);
 169                 ret += pret;
 170                 bufpt = blob_next(bufpt);
 171         /* repeat parsing while there is still enough remaining data in buffer */
 172         } while(len > pos + sizeof(struct blob_attr));
 173
 174         return (ret <= 0);
 175 }
 176
 177 /* append signature to certfile */
 178 static int cert_append(const char *certfile, const char *sigfile) {
 179         FILE *fs;
 180         char filebuf[CERT_BUF_LEN];
 181         struct blob_buf sigbuf;
 182         int len;
 183         int ret;
 184
 185         fs = fopen(sigfile, "r");
 186         if (!fs)
 187                 return 1;
 188
 189         len = fread(&filebuf, 1, CERT_BUF_LEN - 1, fs);
 190         ret = ferror(fs) || !feof(fs) || (len < 64);
 191         fclose(fs);
 192         if (ret)
 193                 return 1;
 194
 195         blob_buf_init(&sigbuf, 0);
 196         blob_put(&sigbuf, CERT_ATTR_SIGNATURE, filebuf, len);
 197         ret = write_file(certfile, sigbuf.head, blob_raw_len(sigbuf.head), true);
 198         blob_buf_free(&sigbuf);
 199         return ret;
 200 }
 201
 202 /* verify the signature of a single chain element */
 203 static int cert_verify_blob(struct blob_attr *cert[CERT_ATTR_MAX],
 204                        const char *pubkeyfile, const char *pubkeydir) {
 205         int i;
 206         char msgfname[256], sigfname[256];
 207         int ret;
 208         char tmpdir[] = "/tmp/ucert-XXXXXX";
 209
 210         if (mkdtemp(tmpdir) == NULL)
 211                 return errno;
 212
 213         snprintf(msgfname, sizeof(msgfname) - 1, "%s/%s", tmpdir, "payload");
 214         snprintf(sigfname, sizeof(sigfname) - 1, "%s/%s", tmpdir, "payload.sig");
 215
 216         for (i = 0; i < CERT_ATTR_MAX; i++) {
 217                 struct blob_attr *v = cert[i];
 218
 219                 if (!v)
 220                         break;
 221
 222                 switch(cert_policy[i].type) {
 223                 case BLOB_ATTR_BINARY:
 224                         write_file(sigfname, blob_data(v), blob_len(v), false);
 225                         break;
 226                 case BLOB_ATTR_NESTED:
 227                         write_file(msgfname, blob_data(v), blob_len(v), false);
 228                         break;
 229                 }
 230         }
 231
 232         ret = usign_v(msgfname, pubkeyfile, pubkeydir, sigfname, quiet);
 233
 234         unlink(msgfname);
 235         unlink(sigfname);
 236         rmdir(tmpdir);
 237
 238         return ret;
 239 }
 240
 241 /* verify cert chain (and message) */
 242 static int chain_verify(const char *msgfile, const char *pubkeyfile,
 243                         const char *pubkeydir, struct list_head *chain) {
 244         struct cert_object *cobj;
 245         struct blob_attr *containertb[CERT_CT_ATTR_MAX];
 246         struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
 247         char tmpdir[] = "/tmp/ucert-XXXXXX";
 248         char chainedpubkey[256] = {0};
 249         char chainedfp[17] = {0};
 250         char extsigfile[256] = {0};
 251         int ret = 1;
 252         int checkmsg = 0;
 253
 254         if (mkdtemp(tmpdir) == NULL)
 255                 return errno;
 256
 257         if (msgfile)
 258                 checkmsg = -1;
 259
 260         list_for_each_entry(cobj, chain, list) {
 261                 /* blob has payload, verify that using signature */
 262                 if (cobj->cert[CERT_ATTR_PAYLOAD]) {
 263                         struct timeval tv;
 264                         uint64_t validfrom;
 265                         uint64_t expiresat;
 266                         uint32_t certtype;
 267
 268                         ret = cert_verify_blob(cobj->cert, chainedpubkey[0]?chainedpubkey:pubkeyfile, pubkeydir);
 269                         if (ret)
 270                                 goto clean_and_return;
 271
 272                         blobmsg_parse(cert_cont_policy,
 273                                       ARRAY_SIZE(cert_cont_policy),
 274                                       containertb,
 275                                       blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
 276                                       blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
 277                         if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
 278                                 ret = 1;
 279                                 if (!quiet)
 280                                         fprintf(stderr, "no ucert in signed payload\n");
 281                                 goto clean_and_return;
 282                         }
 283                         blobmsg_parse(cert_payload_policy,
 284                                       ARRAY_SIZE(cert_payload_policy),
 285                                       payloadtb,
 286                                       blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
 287                                       blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
 288
 289                         if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
 290                             !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
 291                             !payloadtb[CERT_PL_ATTR_EXPIRETIME] ||
 292                             !payloadtb[CERT_PL_ATTR_PUBKEY]) {
 293                                 ret = 1;
 294                                 if (!quiet)
 295                                         fprintf(stderr, "missing mandatory ucert attributes\n");
 296                                 goto clean_and_return;
 297                         }
 298                         certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
 299                         validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
 300                         expiresat = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_EXPIRETIME]);
 301
 302                         if (certtype != CERTTYPE_AUTH) {
 303                                 ret = 2;
 304                                 if (!quiet)
 305                                         fprintf(stderr, "wrong certificate type\n");
 306                                 goto clean_and_return;
 307                         }
 308
 309                         gettimeofday(&tv, NULL);
 310                         if (tv.tv_sec < validfrom ||
 311                             tv.tv_sec >= expiresat) {
 312                                 ret = 3;
 313                                 if (!quiet)
 314                                         fprintf(stderr, "certificate expired\n");
 315                                 goto clean_and_return;
 316                         }
 317
 318                         snprintf(chainedpubkey, sizeof(chainedpubkey) - 1, "%s/%s", tmpdir, "chained-pubkey");
 319                         write_file(chainedpubkey,
 320                                    blobmsg_data(payloadtb[CERT_PL_ATTR_PUBKEY]),
 321                                    blobmsg_data_len(payloadtb[CERT_PL_ATTR_PUBKEY]),
 322                                    false);
 323
 324                         if (usign_f_pubkey(chainedfp, chainedpubkey)) {
 325                                 if (!quiet)
 326                                         fprintf(stderr, "cannot get fingerprint for chained key\n");
 327                                 ret = 2;
 328                                 goto clean_and_return;
 329                         }
 330                         if (pubkeydir && _usign_key_is_revoked(chainedfp, pubkeydir)) {
 331                                 if (!quiet)
 332                                         fprintf(stderr, "key %s has been revoked!\n", chainedfp);
 333                                 ret = 4;
 334                                 goto clean_and_return;
 335                         }
 336                 } else {
 337                 /* blob doesn't have payload, verify message using signature */
 338                         if (msgfile) {
 339                                 snprintf(extsigfile, sizeof(extsigfile) - 1, "%s/%s", tmpdir, "ext-sig");
 340                                 write_file(extsigfile,
 341                                            blob_data(cobj->cert[CERT_ATTR_SIGNATURE]),
 342                                            blob_len(cobj->cert[CERT_ATTR_SIGNATURE]),
 343                                            false);
 344                                 checkmsg = ret = usign_v(msgfile,
 345                                               chainedpubkey[0]?chainedpubkey:pubkeyfile,
 346                                               pubkeydir, extsigfile, quiet);
 347                                 unlink(extsigfile);
 348                         } else {
 349                                 if (!quiet)
 350                                         fprintf(stderr, "stray trailing signature without anything to verify!\n");
 351                                 ret = 1;
 352                         };
 353                 }
 354         }
 355
 356         if (checkmsg == -1 && !quiet)
 357                 fprintf(stderr, "missing signature to verify message!\n");
 358
 359 clean_and_return:
 360         if (chainedpubkey[0])
 361                 unlink(chainedpubkey);
 362         rmdir(tmpdir);
 363         return ret | checkmsg;
 364 }
 365
 366 /* dump single chain element to console */
 367 static void cert_dump_blob(struct blob_attr *cert[CERT_ATTR_MAX]) {
 368         int i;
 369
 370         for (i = 0; i < CERT_ATTR_MAX; i++) {
 371                 struct blob_attr *v = cert[i];
 372
 373                 if (!v)
 374                         continue;
 375
 376                 switch(cert_policy[i].type) {
 377                 case BLOB_ATTR_BINARY:
 378                         fprintf(stdout, "signature:\n---\n%s---\n", (char *) blob_data(v));
 379                         break;
 380                 case BLOB_ATTR_NESTED:
 381                         fprintf(stdout, "payload:\n---\n%s\n---\n", blobmsg_format_json_indent(blob_data(v), false, 0));
 382                         break;
 383                 }
 384         }
 385 }
 386
 387 /* dump certfile to console */
 388 static int cert_dump(const char *certfile) {
 389         struct cert_object *cobj;
 390         static LIST_HEAD(certchain);
 391         unsigned int count = 0;
 392
 393         if (cert_load(certfile, &certchain)) {
 394                 if (!quiet)
 395                         fprintf(stderr, "cannot parse cert\n");
 396                 return 1;
 397         }
 398
 399         list_for_each_entry(cobj, &certchain, list) {
 400                 fprintf(stdout, "=== CHAIN ELEMENT %02u ===\n", ++count);
 401                 cert_dump_blob(cobj->cert);
 402         }
 403
 404         return 0;
 405 }
 406
 407 /* issue an auth certificate for pubkey */
 408 static int cert_issue(const char *certfile, const char *pubkeyfile, const char *seckeyfile) {
 409         struct blob_buf certbuf;
 410         struct blob_buf payloadbuf;
 411         struct timeval tv;
 412         struct stat st;
 413         int pklen, siglen;
 414         int revoker = 1;
 415         void *c;
 416         FILE *pkf, *sigf;
 417         char pkb[512];
 418         char sigb[512];
 419         char fname[256], sfname[256];
 420         char pkfp[17];
 421         char tmpdir[] = "/tmp/ucert-XXXXXX";
 422
 423         pkf = fopen(pubkeyfile, "r");
 424         if (!pkf)
 425                 return -1;
 426
 427         pklen = fread(pkb, 1, 512, pkf);
 428         pkb[pklen] = '\0';
 429
 430         if (pklen < 32)
 431                 return -1;
 432
 433         fclose(pkf);
 434
 435         if (usign_f_pubkey(pkfp, pubkeyfile))
 436                 return -1;
 437
 438         gettimeofday(&tv, NULL);
 439
 440         if (mkdtemp(tmpdir) == NULL)
 441                 return errno;
 442
 443         while (revoker >= 0) {
 444                 blob_buf_init(&payloadbuf, 0);
 445                 c = blobmsg_open_table(&payloadbuf, "ucert");
 446                 blobmsg_add_u32(&payloadbuf, "certtype", revoker?CERTTYPE_REVOKE:CERTTYPE_AUTH);
 447                 blobmsg_add_u64(&payloadbuf, "validfrom", tv.tv_sec);
 448                 if (!revoker) {
 449                         blobmsg_add_u64(&payloadbuf, "expiresat", tv.tv_sec + 60 * 60 * 24 * 365);
 450                         blobmsg_add_string(&payloadbuf, "pubkey", pkb);
 451                 } else {
 452                         blobmsg_add_string(&payloadbuf, "fingerprint", pkfp);
 453                 }
 454
 455                 blobmsg_close_table(&payloadbuf, c);
 456
 457                 snprintf(fname, sizeof(fname) - 1, "%s/%s", tmpdir, revoker?"revoker":"payload");
 458                 write_file(fname, blob_data(payloadbuf.head), blob_len(payloadbuf.head), false);
 459
 460                 snprintf(sfname, sizeof(sfname) - 1, "%s/%s", tmpdir, revoker?"revoker.sig":"payload.sig");
 461                 if (usign_s(fname, seckeyfile, sfname, quiet))
 462                         return 1;
 463
 464                 sigf = fopen(sfname, "r");
 465                 if (!sigf)
 466                         return 1;
 467
 468                 siglen = fread(sigb, 1, 1024, sigf);
 469                 if (siglen < 1)
 470                         return 1;
 471
 472                 sigb[siglen] = '\0';
 473                 fclose(sigf);
 474
 475                 unlink(fname);
 476                 unlink(sfname);
 477
 478                 blob_buf_init(&certbuf, 0);
 479                 blob_put(&certbuf, CERT_ATTR_SIGNATURE, sigb, siglen);
 480                 blob_put(&certbuf, CERT_ATTR_PAYLOAD, blob_data(payloadbuf.head), blob_len(payloadbuf.head));
 481                 snprintf(fname, sizeof(fname) - 1, "%s%s", certfile, revoker?".revoke":"");
 482                 write_file(fname, certbuf.head, blob_raw_len(certbuf.head), true);
 483                 blob_buf_free(&certbuf);
 484                 blob_buf_free(&payloadbuf);
 485
 486                 revoker--;
 487         }
 488
 489         rmdir(tmpdir);
 490
 491         return 0;
 492 }
 493
 494 /* process revoker certificate */
 495 static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
 496         static LIST_HEAD(certchain);
 497         struct cert_object *cobj;
 498         struct blob_attr *containertb[CERT_CT_ATTR_MAX];
 499         struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
 500         struct stat st;
 501         struct timeval tv;
 502         uint64_t validfrom;
 503         uint32_t certtype;
 504         char *fingerprint;
 505         char rfname[512];
 506
 507         int ret;
 508
 509         if (cert_load(certfile, &certchain)) {
 510                 if (!quiet)
 511                         fprintf(stderr, "cannot parse cert\n");
 512                 return 1;
 513         }
 514
 515         list_for_each_entry(cobj, &certchain, list) {
 516                 if (!cobj->cert[CERT_ATTR_PAYLOAD])
 517                         return 2;
 518
 519                 /* blob has payload, verify that using signature */
 520                 ret = cert_verify_blob(cobj->cert, NULL, pubkeydir);
 521                 if (ret)
 522                         return ret;
 523
 524                 blobmsg_parse(cert_cont_policy,
 525                               ARRAY_SIZE(cert_cont_policy),
 526                               containertb,
 527                               blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
 528                               blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
 529                 if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
 530                         if (!quiet)
 531                                 fprintf(stderr, "no ucert in signed payload\n");
 532                         return 2;
 533                 }
 534
 535                 blobmsg_parse(cert_payload_policy,
 536                               ARRAY_SIZE(cert_payload_policy),
 537                               payloadtb,
 538                               blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
 539                               blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
 540
 541                 if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
 542                     !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
 543                     !payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]) {
 544                         if (!quiet)
 545                                 fprintf(stderr, "missing mandatory ucert attributes\n");
 546                         return 2;
 547                 }
 548
 549                 certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
 550                 validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
 551                 fingerprint = blobmsg_get_string(payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]);
 552
 553                 if (certtype != CERTTYPE_REVOKE) {
 554                         if (!quiet)
 555                                 fprintf(stderr, "wrong certificate type\n");
 556                         return 2;
 557                 }
 558
 559                 gettimeofday(&tv, NULL);
 560                 if (tv.tv_sec < validfrom) {
 561                         return 3;
 562                 }
 563
 564                 snprintf(rfname, sizeof(rfname)-1, "%s/%s", pubkeydir, fingerprint);
 565                 /* check if entry in pubkeydir exists */
 566                 if (stat(rfname, &st) == 0) {
 567                         if (_usign_key_is_revoked(fingerprint, pubkeydir)) {
 568                                 if (!quiet)
 569                                         fprintf(stdout, "existing revoker deadlink for key %s\n", fingerprint);
 570                                 continue;
 571                         };
 572
 573                         /* remove any other entry */
 574                         if (unlink(rfname))
 575                                 return -1;
 576                 }
 577
 578                 ret = symlink(".revoked.", rfname);
 579                 if (ret)
 580                         return ret;
 581
 582                 if (!quiet)
 583                         fprintf(stdout, "created revoker deadlink for key %s\n", fingerprint);
 584         };
 585
 586         return ret;
 587 }
 588
 589 /* load and verify certfile (and message) */
 590 static int cert_verify(const char *certfile, const char *pubkeyfile, const char *pubkeydir, const char *msgfile) {
 591         static LIST_HEAD(certchain);
 592
 593         if (cert_load(certfile, &certchain)) {
 594                 if (!quiet)
 595                         fprintf(stderr, "cannot parse cert\n");
 596                 return 1;
 597         }
 598
 599         return chain_verify(msgfile, pubkeyfile, pubkeydir, &certchain);
 600 }
 601
 602 /* output help */
 603 static int usage(const char *cmd)
 604 {
 605         fprintf(stderr,
 606                 "Usage: %s <command> <options>\n"
 607                 "Commands:\n"
 608                 "  -A:                  append signature (needs -c and -x)\n"
 609                 "  -D:                  dump (needs -c)\n"
 610                 "  -I:                  issue cert and revoker (needs -c and -p and -s)\n"
 611                 "  -R:                  process revoker certificate (needs -c and -P)\n"
 612                 "  -V:                  verify (needs -c and -p|-P, may have -m)\n"
 613                 "Options:\n"
 614                 "  -c <file>:           certificate file\n"
 615                 "  -m <file>:           message file (verify only)\n"
 616                 "  -p <file>:           public key file\n"
 617                 "  -P <path>:           public key directory (verify only)\n"
 618                 "  -q:                  quiet (do not print verification result, use return code only)\n"
 619                 "  -s <file>:           secret key file (issue only)\n"
 620                 "  -x <file>:           signature file\n"
 621                 "\n",
 622                 cmd);
 623         return 1;
 624 }
 625
 626 /* parse command line options and call functions */
 627 int main(int argc, char *argv[]) {
 628         int ch;
 629         const char *msgfile = NULL;
 630         const char *sigfile = NULL;
 631         const char *pubkeyfile = NULL;
 632         const char *pubkeydir = NULL;
 633         const char *certfile = NULL;
 634         const char *seckeyfile = NULL;
 635
 636         quiet = false;
 637         while ((ch = getopt(argc, argv, "ADIRVc:m:p:P:qs:x:")) != -1) {
 638                 switch (ch) {
 639                 case 'A':
 640                         if (cmd != CMD_NONE)
 641                                 return usage(argv[0]);
 642                         cmd = CMD_APPEND;
 643                         break;
 644                 case 'D':
 645                         if (cmd != CMD_NONE)
 646                                 return usage(argv[0]);
 647                         cmd = CMD_DUMP;
 648                         break;
 649                 case 'I':
 650                         if (cmd != CMD_NONE)
 651                                 return usage(argv[0]);
 652                         cmd = CMD_ISSUE;
 653                         break;
 654                 case 'R':
 655                         if (cmd != CMD_NONE)
 656                                 return usage(argv[0]);
 657                         cmd = CMD_REVOKE;
 658                         break;
 659                 case 'V':
 660                         if (cmd != CMD_NONE)
 661                                 return usage(argv[0]);
 662                         cmd = CMD_VERIFY;
 663                         break;
 664                 case 'c':
 665                         if (certfile || cmd == CMD_NONE)
 666                                 return usage(argv[0]);
 667                         certfile = optarg;
 668                         break;
 669                 case 'm':
 670                         if (msgfile || cmd != CMD_VERIFY)
 671                                 return usage(argv[0]);
 672                         msgfile = optarg;
 673                         break;
 674                 case 'p':
 675                         if (pubkeyfile || (cmd != CMD_VERIFY && cmd != CMD_ISSUE) || cmd == CMD_NONE)
 676                                 return usage(argv[0]);
 677                         pubkeyfile = optarg;
 678                         break;
 679                 case 'P':
 680                         if (pubkeydir || (cmd != CMD_VERIFY && cmd != CMD_REVOKE) || cmd == CMD_NONE)
 681                                 return usage(argv[0]);
 682                         pubkeydir = optarg;
 683                         break;
 684                 case 'q':
 685                         if (quiet)
 686                                 return usage(argv[0]);
 687                         quiet = true;
 688                         break;
 689                 case 's':
 690                         if (seckeyfile || cmd != CMD_ISSUE || cmd == CMD_NONE)
 691                                 return usage(argv[0]);
 692                         seckeyfile = optarg;
 693                         break;
 694                 case 'x':
 695                         if (sigfile || cmd != CMD_APPEND || cmd == CMD_NONE)
 696                                 return usage(argv[0]);
 697                         sigfile = optarg;
 698                         break;
 699                 default:
 700                         return usage(argv[0]);
 701                 }
 702         }
 703
 704         switch (cmd) {
 705         case CMD_APPEND:
 706                 if (certfile && sigfile)
 707                         return cert_append(certfile, sigfile);
 708                 else
 709                         return usage(argv[0]);
 710         case CMD_DUMP:
 711                 if (certfile)
 712                         return cert_dump(certfile);
 713                 else
 714                         return usage(argv[0]);
 715         case CMD_ISSUE:
 716                 if (certfile && pubkeyfile && seckeyfile)
 717                         return cert_issue(certfile, pubkeyfile, seckeyfile);
 718                 else
 719                         return usage(argv[0]);
 720         case CMD_REVOKE:
 721                 if (certfile && pubkeydir)
 722                         return cert_process_revoker(certfile, pubkeydir);
 723                 else
 724                         return usage(argv[0]);
 725         case CMD_VERIFY:
 726                 if (certfile && (pubkeyfile || pubkeydir))
 727                         return cert_verify(certfile, pubkeyfile, pubkeydir, msgfile);
 728                 else
 729                         return usage(argv[0]);
 730         case CMD_NONE:
 731                 return usage(argv[0]);
 732         }
 733
 734         /* unreachable */
 735         return usage(argv[0]);
 736 }