mdw@git.distorted.org.uk Git - catacomb/blob - progs/catcrypt.c

   1 /* -*-c-*-
   2  *
   3  * Command-line encryption tool
   4  *
   5  * (c) 2004 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Catacomb.
  11  *
  12  * Catacomb is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * Catacomb is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with Catacomb; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 #define _FILE_OFFSET_BITS 64
  31
  32 #include "config.h"
  33
  34 #include <errno.h>
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38
  39 #include <mLib/base64.h>
  40 #include <mLib/dstr.h>
  41 #include <mLib/mdwopt.h>
  42 #include <mLib/quis.h>
  43 #include <mLib/report.h>
  44 #include <mLib/sub.h>
  45
  46 #include "buf.h"
  47 #include "ct.h"
  48 #include "rand.h"
  49 #include "noise.h"
  50 #include "mprand.h"
  51 #include "key.h"
  52 #include "cc.h"
  53
  54 #include "gaead.h"
  55 #include "ectab.h"
  56 #include "ptab.h"
  57
  58 /*----- Static variables --------------------------------------------------*/
  59
  60 static const char *keyring = "keyring";
  61
  62 /*----- Data format -------------------------------------------------------*/
  63
  64 /* --- Overview --- *
  65  *
  66  * The encrypted message is divided into chunks, each preceded by a two-octet
  67  * length.  The chunks don't need to be large -- the idea is that we can
  68  * stream the chunks in and out.
  69  *
  70  * The first chunk is a header.  It contains the decryption key-id, and maybe
  71  * the verification key-id if the message is signed.
  72  *
  73  * Next comes the key-encapsulation chunk.  This is decrypted in some
  74  * KEM-specific way to yield a secret hash.  The hash is expanded using an
  75  * MGF (or similar) to make a symmetric encryption and MAC key.
  76  *
  77  * If the message is signed, there comes a signature chunk.  The signature is
  78  * on the header and key-encapsulation chunks, and further output of the MGF.
  79  * This means that the recipient can modify the message and still have a
  80  * valid signature, so it's not useful for proving things to other people;
  81  * but it also means that the recipient knows that the message is from
  82  * someone who knows the hash, which limits the possiblities to (a) whoever
  83  * encrypted the message (good!) and (b) whoever knows the recipient's
  84  * private key.
  85  *
  86  * Then come message chunks.  Each one begins with a MAC over an implicit
  87  * sequence number and the ciphertext.  The final chunk's ciphertext is
  88  * empty; no other chunk is empty.  Thus can the correct end-of-file be
  89  * discerned.
  90  */
  91
  92 /*----- Chunk I/O ---------------------------------------------------------*/
  93
  94 static void chunk_write(enc *e, buf *b)
  95 {
  96   octet l[2];
  97   size_t n = BLEN(b);
  98   assert(n <= MASK16);
  99   STORE16(l, n);
 100   if (e->ops->write(e, l, 2) ||
 101       e->ops->write(e, BBASE(b), BLEN(b)))
 102     die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
 103 }
 104
 105 static void chunk_read(enc *e, dstr *d, buf *b)
 106 {
 107   octet l[2];
 108   size_t n;
 109
 110   dstr_reset(d);
 111   errno = 0;
 112   if (e->ops->read(e, l, 2) != 2)
 113     goto err;
 114   n = LOAD16(l);
 115   dstr_ensure(d, n);
 116   if (e->ops->read(e, d->buf, n) != n)
 117     goto err;
 118   d->len = n;
 119   buf_init(b, d->buf, d->len);
 120   return;
 121
 122 err:
 123   if (!errno) die(EXIT_FAILURE, "unexpected end-of-file on input");
 124   else die(EXIT_FAILURE, "error reading input: %s", strerror(errno));
 125 }
 126
 127 /*----- Encryption --------------------------------------------------------*/
 128
 129 static int encrypt(int argc, char *argv[])
 130 {
 131   const char *fn, *of = 0, *kn = "ccrypt", *skn = 0;
 132   FILE *ofp = 0;
 133   FILE *fp = 0;
 134   const char *ef = "binary";
 135   fprogress ff;
 136   const char *err;
 137   int i;
 138   int en;
 139   size_t n, chsz;
 140   dstr d = DSTR_INIT;
 141   buf b;
 142   size_t seq;
 143   char bb[65536];
 144   unsigned f = 0;
 145   key_file kf;
 146   key *k;
 147   key *sk = 0;
 148   kem *km;
 149   bulk *bc;
 150   sig *s = 0;
 151   const encops *eo;
 152   enc *e;
 153
 154 #define f_bogus 1u
 155 #define f_nocheck 2u
 156 #define f_progress 4u
 157
 158   for (;;) {
 159     static const struct option opt[] = {
 160       { "key",          OPTF_ARGREQ,    0,      'k' },
 161       { "sign-key",     OPTF_ARGREQ,    0,      's' },
 162       { "armour",       0,              0,      'a' },
 163       { "armor",        0,              0,      'a' },
 164       { "format",       OPTF_ARGREQ,    0,      'f' },
 165       { "output",       OPTF_ARGREQ,    0,      'o' },
 166       { "progress",     0,              0,      'p' },
 167       { "nocheck",      0,              0,      'C' },
 168       { 0,              0,              0,      0 }
 169     };
 170     i = mdwopt(argc, argv, "k:s:af:o:pC", opt, 0, 0, 0);
 171     if (i < 0) break;
 172     switch (i) {
 173       case 'k': kn = optarg; break;
 174       case 's': skn = optarg; break;
 175       case 'a': ef = "pem"; break;
 176       case 'f': ef = optarg; break;
 177       case 'o': of = optarg; break;
 178       case 'p': f |= f_progress; break;
 179       case 'C': f |= f_nocheck; break;
 180       default: f |= f_bogus; break;
 181     }
 182   }
 183   if (argc - optind > 1 || (f & f_bogus))
 184     die(EXIT_FAILURE, "Usage: encrypt [-OPTIONS] [FILE]");
 185
 186   if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0))
 187     die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
 188   if ((k = key_bytag(&kf, kn)) == 0)
 189     die(EXIT_FAILURE, "key `%s' not found", kn);
 190   if (skn && (sk = key_bytag(&kf, skn)) == 0)
 191     die(EXIT_FAILURE, "key `%s' not found", skn);
 192
 193   if ((eo = getenc(ef)) == 0)
 194     die(EXIT_FAILURE, "encoding `%s' not found", ef);
 195
 196   fn = optind < argc ? argv[optind++] : "-";
 197   if (strcmp(fn, "-") == 0)
 198     fp = stdin;
 199   else if ((fp = fopen(fn, "rb")) == 0) {
 200     die(EXIT_FAILURE, "couldn't open file `%s': %s",
 201         fn, strerror(errno));
 202   }
 203
 204   if (!of || strcmp(of, "-") == 0)
 205     ofp = stdout;
 206   else if ((ofp = fopen(of, eo->wmode)) == 0) {
 207     die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
 208         of, strerror(errno));
 209   }
 210
 211   dstr_reset(&d);
 212   key_fulltag(k, &d);
 213   e = initenc(eo, ofp, "CATCRYPT ENCRYPTED MESSAGE");
 214   km = getkem(k, "cckem", 0, &bc);
 215   if (!(f & f_nocheck) && (err = km->ops->check(km)) != 0)
 216     moan("key %s fails check: %s", d.buf, err);
 217   if (sk) {
 218     dstr_reset(&d);
 219     key_fulltag(sk, &d);
 220     s = getsig(sk, "ccsig", 1);
 221     if ((err = s->ops->check(s)) != 0)
 222       moan("key %s fails check: %s", d.buf, err);
 223   }
 224
 225   /* --- Build the header chunk --- */
 226
 227   dstr_reset(&d);
 228   dstr_ensure(&d, 256);
 229   buf_init(&b, d.buf, 256);
 230   buf_putu32(&b, k->id);
 231   if (sk) buf_putu32(&b, sk->id);
 232   assert(BOK(&b));
 233   if (s) GH_HASHBUF16(s->h, BBASE(&b), BLEN(&b));
 234   chunk_write(e, &b);
 235
 236   /* --- Build the KEM chunk --- */
 237
 238   dstr_reset(&d);
 239   if (setupkem(km, &d, bc)) die(EXIT_FAILURE, "failed to encapsulate key");
 240   buf_init(&b, d.buf, d.len);
 241   BSTEP(&b, d.len);
 242   if (s) GH_HASHBUF16(s->h, BBASE(&b), BLEN(&b));
 243   chunk_write(e, &b);
 244
 245   /* --- Write the signature chunk --- */
 246
 247   if (s) {
 248     GC_ENCRYPT(km->cx, 0, bb, 1024);
 249     GH_HASH(s->h, bb, 1024);
 250     dstr_reset(&d);
 251     if ((en = s->ops->doit(s, &d)) != 0)
 252       die(EXIT_FAILURE, "error creating signature: %s", key_strerror(en));
 253     buf_init(&b, d.buf, d.len);
 254     BSTEP(&b, d.len);
 255     chunk_write(e, &b);
 256   }
 257
 258   /* --- Now do the main crypto --- */
 259
 260   if (f & f_progress) {
 261     if (fprogress_init(&ff, fn, fp)) {
 262       die(EXIT_FAILURE, "failed to initialize progress display: %s",
 263           strerror(errno));
 264     }
 265   }
 266
 267   n = bc->ops->overhead(bc);
 268   dstr_ensure(&d, sizeof(bb) + n);
 269   seq = 0;
 270   chsz = MASK16 - n;
 271   do {
 272     n = fread(bb, 1, chsz, fp);
 273     if (f & f_progress) fprogress_update(&ff, n);
 274     buf_init(&b, d.buf, d.sz);
 275     if ((err = bc->ops->doit(bc, seq, &b, bb, n)) != 0) {
 276       if (f & f_progress) fprogress_done(&ff);
 277       die(EXIT_FAILURE, "failed to encrypt packet: %s\n", err);
 278     }
 279     seq++;
 280     chunk_write(e, &b);
 281   } while (n);
 282
 283   /* --- All done --- */
 284
 285   if (f & f_progress) fprogress_done(&ff);
 286   e->ops->encdone(e);
 287   bc->ops->destroy(bc);
 288   freeenc(e);
 289   if (s) freesig(s);
 290   freekem(km);
 291   if (fp != stdin) fclose(fp);
 292   if (of) fclose(ofp);
 293   key_close(&kf);
 294   dstr_destroy(&d);
 295   return (0);
 296
 297 #undef f_bogus
 298 #undef f_nocheck
 299 #undef f_progress
 300 }
 301
 302 /*---- Decryption ---------------------------------------------------------*/
 303
 304 static int decrypt(int argc, char *argv[])
 305 {
 306   const char *fn, *of = 0;
 307   FILE *ofp = 0, *rfp = 0;
 308   FILE *fp = 0;
 309   const char *ef = "binary";
 310   fprogress ff;
 311   int i;
 312   size_t n;
 313   dstr d = DSTR_INIT;
 314   char bb[65536];
 315   buf b;
 316   key_file kf;
 317   size_t seq;
 318   uint32 id;
 319   key *k;
 320   key *sk = 0;
 321   kem *km;
 322   sig *s = 0;
 323   bulk *bc;
 324   unsigned f = 0;
 325   const encops *eo;
 326   const char *err;
 327   int verb = 1;
 328   enc *e;
 329
 330 #define f_bogus 1u
 331 #define f_buffer 2u
 332 #define f_nocheck 4u
 333 #define f_progress 8u
 334
 335   for (;;) {
 336     static const struct option opt[] = {
 337       { "armour",       0,              0,      'a' },
 338       { "armor",        0,              0,      'a' },
 339       { "buffer",       0,              0,      'b' },
 340       { "verbose",      0,              0,      'v' },
 341       { "quiet",        0,              0,      'q' },
 342       { "nocheck",      0,              0,      'C' },
 343       { "format",       OPTF_ARGREQ,    0,      'f' },
 344       { "output",       OPTF_ARGREQ,    0,      'o' },
 345       { "progress",     0,              0,      'p' },
 346       { 0,              0,              0,      0 }
 347     };
 348     i = mdwopt(argc, argv, "abf:o:pqvC", opt, 0, 0, 0);
 349     if (i < 0) break;
 350     switch (i) {
 351       case 'a': ef = "pem"; break;
 352       case 'b': f |= f_buffer; break;
 353       case 'v': verb++; break;
 354       case 'q': if (verb) verb--; break;
 355       case 'C': f |= f_nocheck; break;
 356       case 'f': ef = optarg; break;
 357       case 'o': of = optarg; break;
 358       case 'p': f |= f_progress; break;
 359       default: f |= f_bogus; break;
 360     }
 361   }
 362   if (argc - optind > 1 || (f & f_bogus))
 363     die(EXIT_FAILURE, "Usage: decrypt [-OPTIONS] [FILE]");
 364
 365   if ((eo = getenc(ef)) == 0)
 366     die(EXIT_FAILURE, "encoding `%s' not found", ef);
 367
 368   fn = optind < argc ? argv[optind++] : "-";
 369   if (strcmp(fn, "-") == 0)
 370     fp = stdin;
 371   else if ((fp = fopen(fn, eo->rmode)) == 0) {
 372     die(EXIT_FAILURE, "couldn't open file `%s': %s",
 373         fn, strerror(errno));
 374   }
 375
 376   if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0))
 377     die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
 378
 379   e = initdec(eo, fp, checkbdry, "CATCRYPT ENCRYPTED MESSAGE");
 380
 381   if (f & f_progress) {
 382     if (fprogress_init(&ff, fn, fp)) {
 383       die(EXIT_FAILURE, "failed to initialize progress display: %s",
 384           strerror(errno));
 385     }
 386   }
 387
 388   /* --- Read the header chunk --- */
 389
 390   chunk_read(e, &d, &b);
 391   if (f & f_progress)
 392     fprogress_update(&ff, BLEFT(&b)*e->ops->ncook/e->ops->nraw);
 393   if (buf_getu32(&b, &id)) {
 394     if (f & f_progress) fprogress_done(&ff);
 395     if (verb) printf("FAIL malformed header: missing keyid\n");
 396     exit(EXIT_FAILURE);
 397   }
 398   if ((k = key_byid(&kf, id)) == 0) {
 399     if (f & f_progress) fprogress_done(&ff);
 400     if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
 401     exit(EXIT_FAILURE);
 402   }
 403   if (BLEFT(&b)) {
 404     if (buf_getu32(&b, &id)) {
 405       if (f & f_progress) fprogress_done(&ff);
 406       if (verb) printf("FAIL malformed header: missing signature keyid\n");
 407       exit(EXIT_FAILURE);
 408     }
 409     if ((sk = key_byid(&kf, id)) == 0) {
 410       if (f & f_progress) fprogress_done(&ff);
 411       if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
 412       exit(EXIT_FAILURE);
 413     }
 414   }
 415   if (BLEFT(&b)) {
 416     if (f & f_progress) fprogress_done(&ff);
 417     if (verb) printf("FAIL malformed header: junk at end\n");
 418     exit(EXIT_FAILURE);
 419   }
 420   if (sk) {
 421     s = getsig(sk, "ccsig", 0);
 422     if (!(f & f_nocheck) && verb && (err = s->ops->check(s)) != 0) {
 423       dstr_reset(&d);
 424       key_fulltag(sk, &d);
 425       printf("WARN verification key %s fails check: %s\n", d.buf, err);
 426     }
 427     GH_HASHBUF16(s->h, BBASE(&b), BSZ(&b));
 428   }
 429
 430   /* --- Find the key --- */
 431
 432   km = getkem(k, "cckem", 1, &bc);
 433
 434   /* --- Read the KEM chunk --- */
 435
 436   chunk_read(e, &d, &b);
 437   if (f & f_progress)
 438     fprogress_update(&ff, BLEFT(&b)*e->ops->ncook/e->ops->nraw);
 439   if (setupkem(km, &d, bc)) {
 440     if (f & f_progress) fprogress_done(&ff);
 441     if (verb) printf("FAIL failed to decapsulate key\n");
 442     exit(EXIT_FAILURE);
 443   }
 444   if (s) GH_HASHBUF16(s->h, d.buf, d.len);
 445
 446   /* --- Verify the signature, if there is one --- */
 447
 448   if (sk) {
 449     dstr_reset(&d);
 450     dstr_ensure(&d, 1024);
 451     GC_ENCRYPT(km->cx, 0, d.buf, 1024);
 452     GH_HASH(s->h, d.buf, 1024);
 453     chunk_read(e, &d, &b);
 454     if (f & f_progress)
 455       fprogress_update(&ff, BLEFT(&b)*e->ops->ncook/e->ops->nraw);
 456     if (s->ops->doit(s, &d)) {
 457       if (f & f_progress) fprogress_done(&ff);
 458       if (verb) printf("FAIL signature verification failed\n");
 459       exit(EXIT_FAILURE);
 460     }
 461     if (verb) {
 462       dstr_reset(&d);
 463       key_fulltag(sk, &d);
 464       if (f & f_progress) fprogress_clear(&ff);
 465       printf("INFO good-signature %s\n", d.buf);
 466     }
 467     freesig(s);
 468   } else if (verb) {
 469     if (f & f_progress) fprogress_clear(&ff);
 470     printf("INFO no-signature\n");
 471   }
 472
 473   /* --- Now decrypt the main body --- */
 474
 475   if (!of || strcmp(of, "-") == 0) {
 476     ofp = stdout;
 477     f |= f_buffer;
 478   }
 479   if (!(f & f_buffer)) {
 480     if ((ofp = fopen(of, "wb")) == 0) {
 481       if (f & f_progress) fprogress_done(&ff);
 482       die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
 483           of, strerror(errno));
 484     }
 485     rfp = ofp;
 486   } else if ((rfp = tmpfile()) == 0) {
 487     if (f & f_progress) fprogress_done(&ff);
 488     die(EXIT_FAILURE, "couldn't create temporary file: %s", strerror(errno));
 489   }
 490
 491   seq = 0;
 492   dstr_ensure(&d, bc->ops->overhead(bc));
 493   dstr_ensure(&d, 4);
 494   for (;;) {
 495     chunk_read(e, &d, &b);
 496     if (f & f_progress)
 497       fprogress_update(&ff, BLEFT(&b)*e->ops->ncook/e->ops->nraw);
 498     buf_init(&b, bb, sizeof(bb));
 499     if ((err = bc->ops->doit(bc, seq, &b, d.buf, d.len)) != 0) {
 500       if (f & f_progress) fprogress_done(&ff);
 501       if (verb) printf("FAIL bad ciphertext chunk: %s\n", err);
 502       exit(EXIT_FAILURE);
 503     }
 504     seq++;
 505     if (!BLEN(&b)) break;
 506     if (fwrite(BBASE(&b), 1, BLEN(&b), rfp) != BLEN(&b)) {
 507       if (f & f_progress) fprogress_done(&ff);
 508       if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
 509       exit(EXIT_FAILURE);
 510     }
 511   }
 512
 513   if (f & f_progress) fprogress_done(&ff);
 514   if (fflush(rfp) || ferror(rfp)) {
 515     if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
 516     exit(EXIT_FAILURE);
 517   }
 518   if (f & f_buffer) {
 519     if (!ofp && (ofp = fopen(of, "wb")) == 0) {
 520       die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
 521           of, strerror(errno));
 522     }
 523     rewind(rfp);
 524     if (f & f_progress) fprogress_init(&ff, "copying buffer", rfp);
 525     dstr_reset(&d);
 526     dstr_ensure(&d, 65536);
 527     if (verb && ofp == stdout) printf("DATA\n");
 528     for (;;) {
 529       n = fread(d.buf, 1, d.sz, rfp);
 530       if (!n) break;
 531       if (f & f_progress) fprogress_update(&ff, n);
 532       if (fwrite(d.buf, 1, n, ofp) < n) {
 533         if (f & f_progress) fprogress_done(&ff);
 534         die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
 535       }
 536     }
 537     if (f & f_progress) fprogress_done(&ff);
 538     if (ferror(rfp) || fclose(rfp))
 539       die(EXIT_FAILURE, "error unbuffering output: %s", strerror(errno));
 540   }
 541
 542   e->ops->decdone(e);
 543   if (verb && ofp != stdout)
 544     printf("OK decrypted successfully\n");
 545   if (ofp && (fflush(ofp) || ferror(ofp) || fclose(ofp)))
 546       die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
 547   bc->ops->destroy(bc);
 548   freeenc(e);
 549   freekem(km);
 550   if (fp != stdin) fclose(fp);
 551   key_close(&kf);
 552   dstr_destroy(&d);
 553   return (0);
 554
 555 #undef f_bogus
 556 #undef f_buffer
 557 #undef f_nocheck
 558 #undef f_progress
 559 }
 560
 561 /*----- Main code ---------------------------------------------------------*/
 562
 563 #define LISTS(LI)                                                       \
 564   LI("Lists", list,                                                     \
 565      listtab[i].name, listtab[i].name)                                  \
 566   LI("Key-encapsulation mechanisms", kem,                               \
 567      kemtab[i].name, kemtab[i].name)                                    \
 568   LI("Bulk crypto transforms", bulk,                                    \
 569      bulktab[i].name, bulktab[i].name)                                  \
 570   LI("Signature schemes", sig,                                          \
 571      sigtab[i].name, sigtab[i].name)                                    \
 572   LI("Encodings", enc,                                                  \
 573      enctab[i].name, enctab[i].name)                                    \
 574   LI("Symmetric encryption algorithms", cipher,                         \
 575      gciphertab[i], gciphertab[i]->name)                                \
 576   LI("Authenticated encryption schemes", aead,                          \
 577      gaeadtab[i], gaeadtab[i]->name)                                    \
 578   LI("Hash functions", hash,                                            \
 579      ghashtab[i], ghashtab[i]->name)                                    \
 580   LI("Message authentication codes", mac,                               \
 581      gmactab[i], gmactab[i]->name)
 582
 583 MAKELISTTAB(listtab, LISTS)
 584
 585 int cmd_show(int argc, char *argv[])
 586 {
 587   return (displaylists(listtab, argv + 1));
 588 }
 589
 590 static int cmd_help(int, char **);
 591
 592 static cmd cmdtab[] = {
 593   { "help", cmd_help, "help [COMMAND...]" },
 594   { "show", cmd_show, "show [ITEM...]" },
 595   CMD_ENCODE,
 596   CMD_DECODE,
 597   { "encrypt", encrypt,
 598     "encrypt [-apC] [-k TAG] [-s TAG] [-f FORMAT]\n\t\
 599 [-o OUTPUT] [FILE]", "\
 600 Options:\n\
 601 \n\
 602 -a, --armour            Same as `-f pem'.\n\
 603 -f, --format=FORMAT     Encode as FORMAT.\n\
 604 -k, --key=TAG           Use public encryption key named by TAG.\n\
 605 -s, --sign-key=TAG      Use private signature key named by TAG.\n\
 606 -o, --output=FILE       Write output to FILE.\n\
 607 -p, --progress          Show progress on large files.\n\
 608 -C, --nocheck           Don't check the public key.\n\
 609 " },
 610   { "decrypt", decrypt,
 611     "decrypt [-abpqvC] [-f FORMAT] [-o OUTPUT] [FILE]", "\
 612 Options:\n\
 613 \n\
 614 -a, --armour            Same as `-f pem'.\n\
 615 -b, --buffer            Buffer output until we're sure we have it all.\n\
 616 -f, --format=FORMAT     Decode as FORMAT.\n\
 617 -o, --output=FILE       Write output to FILE.\n\
 618 -p, --progress          Show progress on large files.\n\
 619 -q, --quiet             Produce fewer messages.\n\
 620 -v, --verbose           Produce more verbose messages.\n\
 621 -C, --nocheck           Don't check the private key.\n\
 622 " },
 623   { 0, 0, 0 }
 624 };
 625
 626 static int cmd_help(int argc, char **argv)
 627 {
 628   sc_help(cmdtab, stdout, argv + 1);
 629   return (0);
 630 }
 631
 632 void version(FILE *fp)
 633 {
 634   pquis(fp, "$, Catacomb version " VERSION "\n");
 635 }
 636
 637 static void usage(FILE *fp)
 638 {
 639   pquis(fp, "Usage: $ [-k KEYRING] COMMAND [ARGS]\n");
 640 }
 641
 642 void help_global(FILE *fp)
 643 {
 644   usage(fp);
 645   fputs("\n\
 646 Encrypt and decrypt files.\n\
 647 \n\
 648 Global command-line options:\n\
 649 \n\
 650 -h, --help [COMMAND...] Show this help message, or help for COMMANDs.\n\
 651 -v, --version           Show program version number.\n\
 652 -u, --usage             Show a terse usage message.\n\
 653 \n\
 654 -k, --keyring=FILE      Read keys from FILE.\n",
 655         fp);
 656 }
 657
 658 /* --- @main@ --- *
 659  *
 660  * Arguments:   @int argc@ = number of command line arguments
 661  *              @char *argv[]@ = vector of command line arguments
 662  *
 663  * Returns:     Zero if successful, nonzero otherwise.
 664  *
 665  * Use:         Encrypts or decrypts files.
 666  */
 667
 668 int main(int argc, char *argv[])
 669 {
 670   unsigned f = 0;
 671
 672 #define f_bogus 1u
 673
 674   /* --- Initialize the library --- */
 675
 676   ego(argv[0]);
 677   sub_init();
 678   rand_noisesrc(RAND_GLOBAL, &noise_source);
 679   rand_seed(RAND_GLOBAL, 160);
 680
 681   /* --- Parse options --- */
 682
 683   for (;;) {
 684     static struct option opts[] = {
 685       { "help",         0,              0,      'h' },
 686       { "version",      0,              0,      'v' },
 687       { "usage",        0,              0,      'u' },
 688       { "keyring",      OPTF_ARGREQ,    0,      'k' },
 689       { 0,              0,              0,      0 }
 690     };
 691     int i = mdwopt(argc, argv, "+hvu k:", opts, 0, 0, 0);
 692     if (i < 0)
 693       break;
 694     switch (i) {
 695       case 'h':
 696         sc_help(cmdtab, stdout, argv + optind);
 697         exit(0);
 698         break;
 699       case 'v':
 700         version(stdout);
 701         exit(0);
 702         break;
 703       case 'u':
 704         usage(stdout);
 705         exit(0);
 706       case 'k':
 707         keyring = optarg;
 708         break;
 709       default:
 710         f |= f_bogus;
 711         break;
 712     }
 713   }
 714
 715   argc -= optind;
 716   argv += optind;
 717   optind = 0;
 718   if (f & f_bogus || argc < 1) {
 719     usage(stderr);
 720     exit(EXIT_FAILURE);
 721   }
 722
 723   /* --- Dispatch to the correct subcommand handler --- */
 724
 725   return (findcmd(cmdtab, argv[0])->cmd(argc, argv));
 726
 727 #undef f_bogus
 728 }
 729
 730 /*----- That's all, folks -------------------------------------------------*/