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

   1 /* -*-c-*-
   2  *
   3  * $Id$
   4  *
   5  * Command-line encryption tool
   6  *
   7  * (c) 2004 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Header files ------------------------------------------------------*/
  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 "rand.h"
  48 #include "noise.h"
  49 #include "mprand.h"
  50 #include "key.h"
  51 #include "cc.h"
  52
  53 #include "ectab.h"
  54 #include "ptab.h"
  55
  56 /*----- Utilities ---------------------------------------------------------*/
  57
  58 /* --- @keyreport@ --- *
  59  *
  60  * Arguments:   @const char *file@ = filename containing the error
  61  *              @int line@ = line number in file
  62  *              @const char *err@ = error text message
  63  *              @void *p@ = unimportant pointer
  64  *
  65  * Returns:     ---
  66  *
  67  * Use:         Reports errors during the opening of a key file.
  68  */
  69
  70 static void keyreport(const char *file, int line, const char *err, void *p)
  71 {
  72   moan("error in keyring `%s' at line `%s': %s", file, line, err);
  73 }
  74
  75 /*----- Static variables --------------------------------------------------*/
  76
  77 static const char *keyring = "keyring";
  78
  79 /*----- Data format -------------------------------------------------------*/
  80
  81 /* --- Overview --- *
  82  *
  83  * The encrypted message is divided into chunks, each preceded by a two-octet
  84  * length.  The chunks don't need to be large -- the idea is that we can
  85  * stream the chunks in and out.
  86  *
  87  * The first chunk is a header.  It contains the decryption key-id, and maybe
  88  * the verification key-id if the message is signed.
  89  *
  90  * Next comes the key-encapsulation chunk.  This is decrypted in some
  91  * KEM-specific way to yield a secret hash.  This hash is what is signed if
  92  * the message is signed.  The hash is expanded using an MGF (or similar) to
  93  * make a symmetric encryption and MAC key.
  94  *
  95  * If the message is signed, there comes a signature chunk.  The signature is
  96  * on the secret hash.  This means that the recipient can modify the message
  97  * and still have a valid signature, so it's not useful for proving things to
  98  * other people; but it also means that the recipient knows that the message
  99  * is from someone who knows the hash, which limits the possiblities to (a)
 100  * whoever encrypted the message (good!) and (b) whoever knows the
 101  * recipient's private key.
 102  *
 103  * Then come message chunks.  Each one begins with a MAC over an implicit
 104  * sequence number and the ciphertext.  The final chunk's ciphertext is
 105  * empty; no other chunk is empty.  Thus can the correct end-of-file be
 106  * discerned.
 107  */
 108
 109 /*----- Chunk I/O ---------------------------------------------------------*/
 110
 111 static void chunk_write(enc *e, buf *b)
 112 {
 113   octet l[2];
 114   size_t n = BLEN(b);
 115   assert(n <= MASK16);
 116   STORE16(l, n);
 117   if (e->ops->write(e, l, 2) ||
 118       e->ops->write(e, BBASE(b), BLEN(b)))
 119     die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
 120 }
 121
 122 static void chunk_read(enc *e, dstr *d, buf *b)
 123 {
 124   octet l[2];
 125   size_t n;
 126
 127   dstr_reset(d);
 128   errno = 0;
 129   if (e->ops->read(e, l, 2) != 2)
 130     goto err;
 131   n = LOAD16(l);
 132   dstr_ensure(d, n);
 133   if (e->ops->read(e, d->buf, n) != n)
 134     goto err;
 135   d->len = n;
 136   buf_init(b, d->buf, d->len);
 137   return;
 138
 139 err:
 140   if (!errno) die(EXIT_FAILURE, "unexpected end-of-file on input");
 141   else die(EXIT_FAILURE, "error reading input: %s", strerror(errno));
 142 }
 143
 144 /*----- Encryption --------------------------------------------------------*/
 145
 146 static int encrypt(int argc, char *argv[])
 147 {
 148   const char *of = 0, *kn = "ccrypt", *skn = 0;
 149   FILE *ofp = 0;
 150   FILE *fp = 0;
 151   const char *ef = "binary";
 152   const char *err;
 153   int i;
 154   int en;
 155   size_t n;
 156   dstr d = DSTR_INIT;
 157   octet *tag, *ct;
 158   buf b;
 159   size_t seq;
 160   char bb[16384];
 161   unsigned f = 0;
 162   key_file kf;
 163   key *k;
 164   key *sk = 0;
 165   kem *km;
 166   sig *s = 0;
 167   gcipher *cx, *c;
 168   gmac *m;
 169   ghash *h;
 170   const encops *eo;
 171   enc *e;
 172
 173 #define f_bogus 1u
 174
 175   for (;;) {
 176     static const struct option opt[] = {
 177       { "key",          OPTF_ARGREQ,    0,      'k' },
 178       { "sign-key",     OPTF_ARGREQ,    0,      's' },
 179       { "armour",       0,              0,      'a' },
 180       { "armor",        0,              0,      'a' },
 181       { "format",       OPTF_ARGREQ,    0,      'f' },
 182       { "output",       OPTF_ARGREQ,    0,      'o' },
 183       { 0,              0,              0,      0 }
 184     };
 185     i = mdwopt(argc, argv, "k:s:af:o:", opt, 0, 0, 0);
 186     if (i < 0) break;
 187     switch (i) {
 188       case 'k': kn = optarg; break;
 189       case 's': skn = optarg; break;
 190       case 'a': ef = "pem"; break;
 191       case 'f': ef = optarg; break;
 192       case 'o': of = optarg; break;
 193       default: f |= f_bogus; break;
 194     }
 195   }
 196   if (argc - optind > 1 || (f & f_bogus))
 197     die(EXIT_FAILURE, "Usage: encrypt [-OPTIONS] [FILE]");
 198
 199   if (key_open(&kf, keyring, KOPEN_READ, keyreport, 0))
 200     die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
 201   if ((k = key_bytag(&kf, kn)) == 0)
 202     die(EXIT_FAILURE, "key `%s' not found", kn);
 203   if (skn && (sk = key_bytag(&kf, skn)) == 0)
 204     die(EXIT_FAILURE, "key `%s' not found", skn);
 205
 206   if ((eo = getenc(ef)) == 0)
 207     die(EXIT_FAILURE, "encoding `%s' not found", ef);
 208
 209   if (optind == argc)
 210     fp = stdin;
 211   else if (strcmp(argv[optind], "-") == 0) {
 212     fp = stdin;
 213     optind++;
 214   } else if ((fp = fopen(argv[optind], "rb")) == 0) {
 215     die(EXIT_FAILURE, "couldn't open file `%s': %s",
 216         argv[optind], strerror(errno));
 217   } else
 218     optind++;
 219
 220   if (!of || strcmp(of, "-") == 0)
 221     ofp = stdout;
 222   else if ((ofp = fopen(of, eo->wmode)) == 0) {
 223     die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
 224         ofp, strerror(errno));
 225   }
 226
 227   dstr_reset(&d);
 228   key_fulltag(k, &d);
 229   e = initenc(eo, ofp, "CATCRYPT ENCRYPTED MESSAGE", 1);
 230   km = getkem(k, "cckem", 0);
 231   if ((err = km->ops->check(km)) != 0)
 232     moan("key `%s' fails check: %s", d.buf, err);
 233   if (sk) {
 234     dstr_reset(&d);
 235     key_fulltag(sk, &d);
 236     s = getsig(sk, "ccsig", 1);
 237     if ((err = s->ops->check(s)) != 0)
 238       moan("key `%s' fails check: %s", d.buf, err);
 239   }
 240
 241   /* --- Build the header chunk --- */
 242
 243   dstr_reset(&d);
 244   dstr_ensure(&d, 256);
 245   buf_init(&b, d.buf, 256);
 246   buf_putu32(&b, k->id);
 247   if (sk) buf_putu32(&b, sk->id);
 248   assert(BOK(&b));
 249   chunk_write(e, &b);
 250
 251   /* --- Build the KEM chunk --- */
 252
 253   dstr_reset(&d);
 254   if (setupkem(km, &d, &cx, &c, &m))
 255     die(EXIT_FAILURE, "failed to encapsulate key");
 256   buf_init(&b, d.buf, d.len);
 257   BSTEP(&b, d.len);
 258   chunk_write(e, &b);
 259
 260   /* --- Write the signature chunk --- */
 261
 262   if (s) {
 263     GC_ENCRYPT(cx, 0, bb, 1024);
 264     GH_HASH(s->h, bb, 1024);
 265     dstr_reset(&d);
 266     if ((en = s->ops->doit(s, &d)) != 0)
 267       die(EXIT_FAILURE, "error creating signature: %s", key_strerror(en));
 268     buf_init(&b, d.buf, d.len);
 269     BSTEP(&b, d.len);
 270     chunk_write(e, &b);
 271   }
 272
 273   /* --- Now do the main crypto --- */
 274
 275   assert(GC_CLASS(c)->blksz <= sizeof(bb));
 276   dstr_ensure(&d, sizeof(bb) + GM_CLASS(m)->hashsz);
 277   seq = 0;
 278   for (;;) {
 279     h = GM_INIT(m);
 280     STORE32(bb, seq);
 281     GH_HASH(h, bb, 4);
 282     seq++;
 283     if (GC_CLASS(c)->blksz) {
 284       GC_ENCRYPT(cx, 0, bb, GC_CLASS(c)->blksz);
 285       GC_SETIV(c, bb);
 286     }
 287     n = fread(bb, 1, sizeof(bb), fp);
 288     if (!n) break;
 289     buf_init(&b, d.buf, d.sz);
 290     tag = buf_get(&b, GM_CLASS(m)->hashsz);
 291     ct = buf_get(&b, n);
 292     assert(tag); assert(ct);
 293     GC_ENCRYPT(c, bb, ct, n);
 294     GH_HASH(h, ct, n);
 295     GH_DONE(h, tag);
 296     GH_DESTROY(h);
 297     chunk_write(e, &b);
 298   }
 299
 300   /* --- Final terminator packet --- */
 301
 302   buf_init(&b, d.buf, d.sz);
 303   tag = buf_get(&b, GM_CLASS(m)->hashsz);
 304   assert(tag);
 305   GH_DONE(h, tag);
 306   GH_DESTROY(h);
 307   chunk_write(e, &b);
 308
 309   /* --- All done --- */
 310
 311   e->ops->encdone(e);
 312   GM_DESTROY(m);
 313   GC_DESTROY(c);
 314   GC_DESTROY(cx);
 315   freeenc(e);
 316   if (s) freesig(s);
 317   freekem(km);
 318   if (of) fclose(ofp);
 319   key_close(&kf);
 320   dstr_destroy(&d);
 321   return (0);
 322
 323 #undef f_bogus
 324 }
 325
 326 /*---- Decryption ---------------------------------------------------------*/
 327
 328 static int decrypt(int argc, char *argv[])
 329 {
 330   const char *of = 0;
 331   FILE *ofp = 0;
 332   FILE *fp = 0;
 333   const char *ef = "binary";
 334   int i;
 335   dstr d = DSTR_INIT;
 336   buf b;
 337   key_file kf;
 338   size_t seq;
 339   uint32 id;
 340   key *k;
 341   key *sk = 0;
 342   kem *km;
 343   sig *s = 0;
 344   gcipher *cx;
 345   gcipher *c;
 346   ghash *h;
 347   gmac *m;
 348   octet *tag;
 349   unsigned f = 0;
 350   const encops *eo;
 351   const char *err;
 352   int verb = 1;
 353   enc *e;
 354
 355 #define f_bogus 1u
 356
 357   for (;;) {
 358     static const struct option opt[] = {
 359       { "armour",       0,              0,      'a' },
 360       { "armor",        0,              0,      'a' },
 361       { "verbose",      0,              0,      'v' },
 362       { "quiet",        0,              0,      'q' },
 363       { "format",       OPTF_ARGREQ,    0,      'f' },
 364       { "output",       OPTF_ARGREQ,    0,      'o' },
 365       { 0,              0,              0,      0 }
 366     };
 367     i = mdwopt(argc, argv, "af:o:qv", opt, 0, 0, 0);
 368     if (i < 0) break;
 369     switch (i) {
 370       case 'a': ef = "pem"; break;
 371       case 'v': verb++; break;
 372       case 'q': if (verb) verb--; break;
 373       case 'f': ef = optarg; break;
 374       case 'o': of = optarg; break;
 375       default: f |= f_bogus; break;
 376     }
 377   }
 378   if (argc - optind > 1 || (f & f_bogus))
 379     die(EXIT_FAILURE, "Usage: decrypt [-OPTIONS] [FILE]");
 380
 381   if ((eo = getenc(ef)) == 0)
 382     die(EXIT_FAILURE, "encoding `%s' not found", ef);
 383
 384   if (optind == argc)
 385     fp = stdin;
 386   else if (strcmp(argv[optind], "-") == 0) {
 387     fp = stdin;
 388     optind++;
 389   } else if ((fp = fopen(argv[optind], eo->rmode)) == 0) {
 390     die(EXIT_FAILURE, "couldn't open file `%s': %s",
 391         argv[optind], strerror(errno));
 392   } else
 393     optind++;
 394
 395   if (key_open(&kf, keyring, KOPEN_READ, keyreport, 0))
 396     die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
 397
 398   e = initenc(eo, fp, "CATCRYPT ENCRYPTED MESSAGE", 0);
 399
 400   /* --- Read the header chunk --- */
 401
 402   chunk_read(e, &d, &b);
 403   if (buf_getu32(&b, &id)) {
 404     if (verb) printf("FAIL malformed header: missing keyid\n");
 405     exit(EXIT_FAILURE);
 406   }
 407   if ((k = key_byid(&kf, id)) == 0) {
 408     if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
 409     exit(EXIT_FAILURE);
 410   }
 411   if (BLEFT(&b)) {
 412     if (buf_getu32(&b, &id)) {
 413       if (verb) printf("FAIL malformed header: missing signature keyid\n");
 414       exit(EXIT_FAILURE);
 415     }
 416     if ((sk = key_byid(&kf, id)) == 0) {
 417       if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
 418       exit(EXIT_FAILURE);
 419     }
 420   }
 421   if (BLEFT(&b)) {
 422     if (verb) printf("FAIL malformed header: junk at end\n");
 423     exit(EXIT_FAILURE);
 424   }
 425
 426   /* --- Find the key --- */
 427
 428   km = getkem(k, "cckem", 1);
 429
 430   /* --- Read the KEM chunk --- */
 431
 432   chunk_read(e, &d, &b);
 433   if (setupkem(km, &d, &cx, &c, &m)) {
 434     if (verb) printf("FAIL failed to decapsulate key\n");
 435     exit(EXIT_FAILURE);
 436   }
 437
 438   /* --- Verify the signature, if there is one --- */
 439
 440   if (sk) {
 441     s = getsig(sk, "ccsig", 0);
 442     dstr_reset(&d);
 443     key_fulltag(sk, &d);
 444     if (verb && (err = s->ops->check(s)) != 0)
 445       printf("WARN verification key %s fails check: %s\n", d.buf, err);
 446     dstr_reset(&d);
 447     dstr_ensure(&d, 1024);
 448     GC_ENCRYPT(cx, 0, d.buf, 1024);
 449     GH_HASH(s->h, d.buf, 1024);
 450     chunk_read(e, &d, &b);
 451     if (s->ops->doit(s, &d)) {
 452       if (verb) printf("FAIL signature verification failed\n");
 453       exit(EXIT_FAILURE);
 454     }
 455     if (verb) {
 456       dstr_reset(&d);
 457       key_fulltag(sk, &d);
 458       printf("INFO good signature from %s\n", d.buf);
 459     }
 460   } else if (verb)
 461     printf("INFO no signature packet\n");
 462
 463   /* --- Now decrypt the main body --- */
 464
 465   if (!of || strcmp(of, "-") == 0) {
 466     ofp = stdout;
 467     if (verb) printf("DATA\n");
 468   } else if ((ofp = fopen(of, "wb")) == 0) {
 469     die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
 470         ofp, strerror(errno));
 471   }
 472
 473   seq = 0;
 474   dstr_ensure(&d, GC_CLASS(c)->blksz);
 475   dstr_ensure(&d, 4);
 476   for (;;) {
 477     if (GC_CLASS(c)->blksz) {
 478       GC_ENCRYPT(cx, 0, d.buf, GC_CLASS(c)->blksz);
 479       GC_SETIV(c, d.buf);
 480     }
 481     h = GM_INIT(m);
 482     STORE32(d.buf, seq);
 483     GH_HASH(h, d.buf, 4);
 484     seq++;
 485     chunk_read(e, &d, &b);
 486     if ((tag = buf_get(&b, GM_CLASS(m)->hashsz)) == 0) {
 487       if (verb) printf("%sFAIL bad ciphertext chunk: no tag\n",
 488                        ofp == stdout ? "\n" : "");
 489       exit(EXIT_FAILURE);
 490     }
 491     GH_HASH(h, BCUR(&b), BLEFT(&b));
 492     if (memcmp(tag, GH_DONE(h, 0), GM_CLASS(m)->hashsz) != 0) {
 493       if (verb)
 494         printf("%sFAIL bad ciphertext chunk: authentication failure\n",
 495                ofp == stdout ? "\n" : "");
 496       exit(EXIT_FAILURE);
 497     }
 498     if (!BLEFT(&b))
 499       break;
 500     GC_DECRYPT(c, BCUR(&b), BCUR(&b), BLEFT(&b));
 501     if (fwrite(BCUR(&b), 1, BLEFT(&b), ofp) != BLEFT(&b)) {
 502       if (verb) printf("%sFAIL error writing output: %s\n",
 503                        ofp == stdout ? "\n" : "", strerror(errno));
 504       exit(EXIT_FAILURE);
 505     }
 506   }
 507
 508   if (fflush(ofp) || ferror(ofp)) {
 509     if (verb) printf("%sFAIL error writing output: %s\n",
 510                      ofp == stdout ? "\n" : "", strerror(errno));
 511     exit(EXIT_FAILURE);
 512   }
 513
 514   e->ops->decdone(e);
 515   if (verb && ofp != stdout)
 516     printf("OK decrypted successfully\n");
 517   freeenc(e);
 518   GC_DESTROY(c);
 519   GC_DESTROY(cx);
 520   GM_DESTROY(m);
 521   freekem(km);
 522   if (of) fclose(ofp);
 523   key_close(&kf);
 524   dstr_destroy(&d);
 525   return (0);
 526
 527 #undef f_bogus
 528 }
 529
 530 /*----- Test code ---------------------------------------------------------*/
 531
 532 static int encode(int argc, char *argv[])
 533 {
 534   const char *of = 0;
 535   FILE *ofp = 0;
 536   FILE *fp = 0;
 537   const char *ef = "binary";
 538   const char *bd = "MESSAGE";
 539   int i;
 540   size_t n;
 541   char buf[4096];
 542   unsigned f = 0;
 543   const encops *eo;
 544   enc *e;
 545
 546 #define f_bogus 1u
 547
 548   for (;;) {
 549     static const struct option opt[] = {
 550       { "format",       OPTF_ARGREQ,    0,      'f' },
 551       { "boundary",     OPTF_ARGREQ,    0,      'b' },
 552       { "output",       OPTF_ARGREQ,    0,      'o' },
 553       { 0,              0,              0,      0 }
 554     };
 555     i = mdwopt(argc, argv, "f:b:o:", opt, 0, 0, 0);
 556     if (i < 0) break;
 557     switch (i) {
 558       case 'f': ef = optarg; break;
 559       case 'b': bd = optarg; break;
 560       case 'o': of = optarg; break;
 561       default: f |= f_bogus; break;
 562     }
 563   }
 564   if (argc - optind > 1 || (f & f_bogus))
 565     die(EXIT_FAILURE, "Usage: encode [-OPTIONS] [FILE]");
 566
 567   if ((eo = getenc(ef)) == 0)
 568     die(EXIT_FAILURE, "encoding `%s' not found", ef);
 569
 570   if (optind == argc)
 571     fp = stdin;
 572   else if (strcmp(argv[optind], "-") == 0) {
 573     fp = stdin;
 574     optind++;
 575   } else if ((fp = fopen(argv[optind], "rb")) == 0) {
 576     die(EXIT_FAILURE, "couldn't open file `%s': %s",
 577         argv[optind], strerror(errno));
 578   } else
 579     optind++;
 580
 581   if (!of || strcmp(of, "-") == 0)
 582     ofp = stdout;
 583   else if ((ofp = fopen(of, eo->wmode)) == 0) {
 584     die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
 585         ofp, strerror(errno));
 586   }
 587
 588   e = initenc(eo, ofp, bd, 1);
 589
 590   do {
 591     n = fread(buf, 1, sizeof(buf), fp);
 592     if (e->ops->write(e, buf, n))
 593       die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
 594   } while (n == sizeof(buf));
 595   e->ops->encdone(e);
 596   freeenc(e);
 597   return (0);
 598
 599 #undef f_bogus
 600 }
 601
 602 static int decode(int argc, char *argv[])
 603 {
 604   const char *of = 0;
 605   FILE *ofp = 0;
 606   FILE *fp = 0;
 607   const char *ef = "binary";
 608   const char *bd = 0;
 609   int i;
 610   char buf[4096];
 611   unsigned f = 0;
 612   const encops *eo;
 613   enc *e;
 614
 615 #define f_bogus 1u
 616
 617   for (;;) {
 618     static const struct option opt[] = {
 619       { "format",       OPTF_ARGREQ,    0,      'f' },
 620       { "boundary",     OPTF_ARGREQ,    0,      'b' },
 621       { "output",       OPTF_ARGREQ,    0,      'o' },
 622       { 0,              0,              0,      0 }
 623     };
 624     i = mdwopt(argc, argv, "f:b:o:", opt, 0, 0, 0);
 625     if (i < 0) break;
 626     switch (i) {
 627       case 'f': ef = optarg; break;
 628       case 'b': bd = optarg; break;
 629       case 'o': of = optarg; break;
 630       default: f |= f_bogus; break;
 631     }
 632   }
 633   if (argc - optind > 1 || (f & f_bogus))
 634     die(EXIT_FAILURE, "Usage: decode [-OPTIONS] [FILE]");
 635
 636   if ((eo = getenc(ef)) == 0)
 637     die(EXIT_FAILURE, "encoding `%s' not found", ef);
 638
 639   if (optind == argc)
 640     fp = stdin;
 641   else if (strcmp(argv[optind], "-") == 0) {
 642     fp = stdin;
 643     optind++;
 644   } else if ((fp = fopen(argv[optind], eo->rmode)) == 0) {
 645     die(EXIT_FAILURE, "couldn't open file `%s': %s",
 646         argv[optind], strerror(errno));
 647   } else
 648     optind++;
 649
 650   if (!of || strcmp(of, "-") == 0)
 651     ofp = stdout;
 652   else if ((ofp = fopen(of, "wb")) == 0) {
 653     die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
 654         ofp, strerror(errno));
 655   }
 656
 657   e = initenc(eo, fp, bd, 0);
 658
 659   do {
 660     if ((i = e->ops->read(e, buf, sizeof(buf))) < 0)
 661       die(EXIT_FAILURE, "error reading input: %s", strerror(errno));
 662     if (fwrite(buf, 1, i, ofp) < i)
 663       die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
 664   } while (i == sizeof(buf));
 665   e->ops->decdone(e);
 666   freeenc(e);
 667   return (0);
 668
 669 #undef f_bogus
 670 }
 671
 672 /*----- Main code ---------------------------------------------------------*/
 673
 674 #define LISTS(LI)                                                       \
 675   LI("Lists", list,                                                     \
 676      listtab[i].name, listtab[i].name)                                  \
 677   LI("Key-encapsulation mechanisms", kem,                               \
 678      kemtab[i].name, kemtab[i].name)                                    \
 679   LI("Signature schemes", sig,                                          \
 680      sigtab[i].name, sigtab[i].name)                                    \
 681   LI("Encodings", enc,                                                  \
 682      enctab[i].name, enctab[i].name)                                    \
 683   LI("Symmetric encryption algorithms", cipher,                         \
 684      gciphertab[i], gciphertab[i]->name)                                \
 685   LI("Hash functions", hash,                                            \
 686      ghashtab[i], ghashtab[i]->name)                                    \
 687   LI("Message authentication codes", mac,                               \
 688      gmactab[i], gmactab[i]->name)
 689
 690 MAKELISTTAB(listtab, LISTS)
 691
 692 int cmd_show(int argc, char *argv[])
 693 {
 694   return (displaylists(listtab, argv + 1));
 695 }
 696
 697 static int cmd_help(int, char **);
 698
 699 static cmd cmdtab[] = {
 700   { "help", cmd_help, "help [COMMAND...]" },
 701   { "show", cmd_show, "show [ITEM...]" },
 702   { "encode", encode,
 703     "encode [-f FORMAT] [-b LABEL] [-o OUTPUT] [FILE]",
 704     "\
 705 Options:\n\
 706 \n\
 707 -f, --format=FORMAT     Encode to FORMAT.\n\
 708 -b, --boundary=LABEL    PEM boundary is LABEL.\n\
 709 -o, --output=FILE       Write output to FILE.\n\
 710 " },
 711   { "decode", decode,
 712     "decode [-f FORMAT] [-b LABEL] [-o OUTPUT] [FILE]",
 713     "\
 714 Options:\n\
 715 \n\
 716 -f, --format=FORMAT     Decode from FORMAT.\n\
 717 -b, --boundary=LABEL    PEM boundary is LABEL.\n\
 718 -o, --output=FILE       Write output to FILE.\n\
 719 " },
 720   { "encrypt", encrypt,
 721     "encrypt [-a] [-k TAG] [-s TAG] [-f FORMAT]\n\t\
 722 [-o OUTPUT] [FILE]", "\
 723 Options:\n\
 724 \n\
 725 -a, --armour            Same as `-f pem'.\n\
 726 -f, --format=FORMAT     Encode as FORMAT.\n\
 727 -k, --key=TAG           Use public encryption key named by TAG.\n\
 728 -s, --sign-key=TAG      Use private signature key named by TAG.\n\
 729 -o, --output=FILE       Write output to FILE.\n\
 730 " },
 731   { "decrypt", decrypt,
 732     "decrypt [-aqv] [-f FORMAT] [-o OUTPUT] [FILE]", "\
 733 Options:\n\
 734 \n\
 735 -a, --armour            Same as `-f pem'.\n\
 736 -v, --verbose           Produce more verbose messages.\n\
 737 -q, --quiet             Produce fewer messages.\n\
 738 -f, --format=FORMAT     Decode as FORMAT.\n\
 739 -o, --output=FILE       Write output to FILE.\n\
 740 " },
 741   { 0, 0, 0 }
 742 };
 743
 744 static int cmd_help(int argc, char **argv)
 745 {
 746   sc_help(cmdtab, stdout, argv + 1);
 747   return (0);
 748 }
 749
 750 void version(FILE *fp)
 751 {
 752   pquis(fp, "$, Catacomb version " VERSION "\n");
 753 }
 754
 755 static void usage(FILE *fp)
 756 {
 757   pquis(fp, "Usage: $ [-k KEYRING] COMMAND [ARGS]\n");
 758 }
 759
 760 void help_global(FILE *fp)
 761 {
 762   usage(fp);
 763   fputs("\n\
 764 Encrypt and decrypt files.\n\
 765 \n\
 766 Global command-line options:\n\
 767 \n\
 768 -h, --help [COMMAND...] Show this help message, or help for COMMANDs.\n\
 769 -v, --version           Show program version number.\n\
 770 -u, --usage             Show a terse usage message.\n\
 771 \n\
 772 -k, --keyring=FILE      Read keys from FILE.\n",
 773         fp);
 774 }
 775
 776 /* --- @main@ --- *
 777  *
 778  * Arguments:   @int argc@ = number of command line arguments
 779  *              @char *argv[]@ = vector of command line arguments
 780  *
 781  * Returns:     Zero if successful, nonzero otherwise.
 782  *
 783  * Use:         Encrypts or decrypts files.
 784  */
 785
 786 int main(int argc, char *argv[])
 787 {
 788   unsigned f = 0;
 789
 790 #define f_bogus 1u
 791
 792   /* --- Initialize the library --- */
 793
 794   ego(argv[0]);
 795   sub_init();
 796   rand_noisesrc(RAND_GLOBAL, &noise_source);
 797   rand_seed(RAND_GLOBAL, 160);
 798
 799   /* --- Parse options --- */
 800
 801   for (;;) {
 802     static struct option opts[] = {
 803       { "help",         0,              0,      'h' },
 804       { "version",      0,              0,      'v' },
 805       { "usage",        0,              0,      'u' },
 806       { "keyring",      OPTF_ARGREQ,    0,      'k' },
 807       { 0,              0,              0,      0 }
 808     };
 809     int i = mdwopt(argc, argv, "+hvu k:", opts, 0, 0, 0);
 810     if (i < 0)
 811       break;
 812     switch (i) {
 813       case 'h':
 814         sc_help(cmdtab, stdout, argv + optind);
 815         exit(0);
 816         break;
 817       case 'v':
 818         version(stdout);
 819         exit(0);
 820         break;
 821       case 'u':
 822         usage(stdout);
 823         exit(0);
 824       case 'k':
 825         keyring = optarg;
 826         break;
 827       default:
 828         f |= f_bogus;
 829         break;
 830     }
 831   }
 832
 833   argc -= optind;
 834   argv += optind;
 835   optind = 0;
 836   if (f & f_bogus || argc < 1) {
 837     usage(stderr);
 838     exit(EXIT_FAILURE);
 839   }
 840
 841   /* --- Dispatch to the correct subcommand handler --- */
 842
 843   return (findcmd(cmdtab, argv[0])->cmd(argc, argv));
 844
 845 #undef f_bogus
 846 }
 847
 848 /*----- That's all, folks -------------------------------------------------*/