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