[u/mdw/catacomb] / catcrypt.c

/* -*-c-*-
 *
 * $Id$
 *
 * Command-line encryption tool
 *
 * (c) 2004 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of Catacomb.
 *
 * Catacomb is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * Catacomb is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with Catacomb; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/*----- Header files ------------------------------------------------------*/

#include "config.h"

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <mLib/base64.h>
#include <mLib/dstr.h>
#include <mLib/mdwopt.h>
#include <mLib/quis.h>
#include <mLib/report.h>
#include <mLib/sub.h>

#include "buf.h"
#include "rand.h"
#include "noise.h"
#include "mprand.h"
#include "key.h"
#include "cc.h"

#include "ectab.h"
#include "ptab.h"

/*----- Utilities ---------------------------------------------------------*/

/*----- Static variables --------------------------------------------------*/

static const char *keyring = "keyring";

/*----- Data format -------------------------------------------------------*/

/* --- Overview --- *
 *
 * The encrypted message is divided into chunks, each preceded by a two-octet
 * length.  The chunks don't need to be large -- the idea is that we can
 * stream the chunks in and out.
 *
 * The first chunk is a header.  It contains the decryption key-id, and maybe
 * the verification key-id if the message is signed.
 *
 * Next comes the key-encapsulation chunk.  This is decrypted in some
 * KEM-specific way to yield a secret hash.  The hash is expanded using an
 * MGF (or similar) to make a symmetric encryption and MAC key.
 *
 * If the message is signed, there comes a signature chunk.  The signature is
 * on the further output of the MGF.  This means that the recipient can
 * modify the message and still have a valid signature, so it's not useful
 * for proving things to other people; but it also means that the recipient
 * knows that the message is from someone who knows the hash, which limits
 * the possiblities to (a) whoever encrypted the message (good!) and (b)
 * whoever knows the recipient's private key.
 *
 * Then come message chunks.  Each one begins with a MAC over an implicit
 * sequence number and the ciphertext.  The final chunk's ciphertext is
 * empty; no other chunk is empty.  Thus can the correct end-of-file be
 * discerned.
 */

/*----- Chunk I/O ---------------------------------------------------------*/

static void chunk_write(enc *e, buf *b)
{
  octet l[2];
  size_t n = BLEN(b);
  assert(n <= MASK16);
  STORE16(l, n);
  if (e->ops->write(e, l, 2) ||
      e->ops->write(e, BBASE(b), BLEN(b)))
    die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
}

static void chunk_read(enc *e, dstr *d, buf *b)
{
  octet l[2];
  size_t n;

  dstr_reset(d);
  errno = 0;
  if (e->ops->read(e, l, 2) != 2)
    goto err;
  n = LOAD16(l);
  dstr_ensure(d, n);
  if (e->ops->read(e, d->buf, n) != n)
    goto err;
  d->len = n;
  buf_init(b, d->buf, d->len);
  return;

err:
  if (!errno) die(EXIT_FAILURE, "unexpected end-of-file on input");
  else die(EXIT_FAILURE, "error reading input: %s", strerror(errno));
}

/*----- Encryption --------------------------------------------------------*/

static int encrypt(int argc, char *argv[])
{
  const char *of = 0, *kn = "ccrypt", *skn = 0;
  FILE *ofp = 0;
  FILE *fp = 0;
  const char *ef = "binary";
  const char *err;
  int i;
  int en;
  size_t n;
  dstr d = DSTR_INIT;
  octet *tag, *ct;
  buf b;
  size_t seq;
  char bb[16384];
  unsigned f = 0;
  key_file kf;
  key *k;
  key *sk = 0;
  kem *km;
  sig *s = 0;
  gcipher *cx, *c;
  gmac *m;
  ghash *h;
  const encops *eo;
  enc *e;

#define f_bogus 1u

  for (;;) {
    static const struct option opt[] = {
      { "key",		OPTF_ARGREQ,	0,	'k' },
      { "sign-key",	OPTF_ARGREQ,	0,	's' },
      { "armour",	0,		0,	'a' },
      { "armor",	0,		0,	'a' },
      { "format", 	OPTF_ARGREQ,	0,	'f' },
      { "output", 	OPTF_ARGREQ,	0,	'o' },
      { 0,		0,		0,	0 }
    };
    i = mdwopt(argc, argv, "k:s:af:o:", opt, 0, 0, 0);
    if (i < 0) break;
    switch (i) {
      case 'k': kn = optarg; break;
      case 's': skn = optarg; break;
      case 'a': ef = "pem"; break;
      case 'f': ef = optarg; break;
      case 'o': of = optarg; break;
      default: f |= f_bogus; break;
    }
  }
  if (argc - optind > 1 || (f & f_bogus))
    die(EXIT_FAILURE, "Usage: encrypt [-OPTIONS] [FILE]");

  if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0))
    die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
  if ((k = key_bytag(&kf, kn)) == 0)
    die(EXIT_FAILURE, "key `%s' not found", kn);
  if (skn && (sk = key_bytag(&kf, skn)) == 0)
    die(EXIT_FAILURE, "key `%s' not found", skn);

  if ((eo = getenc(ef)) == 0)
    die(EXIT_FAILURE, "encoding `%s' not found", ef);

  if (optind == argc)
    fp = stdin;
  else if (strcmp(argv[optind], "-") == 0) {
    fp = stdin;
    optind++;
  } else if ((fp = fopen(argv[optind], "rb")) == 0) {
    die(EXIT_FAILURE, "couldn't open file `%s': %s",
	argv[optind], strerror(errno));
  } else
    optind++;

  if (!of || strcmp(of, "-") == 0)
    ofp = stdout;
  else if ((ofp = fopen(of, eo->wmode)) == 0) {
    die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
	ofp, strerror(errno));
  }

  dstr_reset(&d);
  key_fulltag(k, &d);
  e = initenc(eo, ofp, "CATCRYPT ENCRYPTED MESSAGE");
  km = getkem(k, "cckem", 0);
  if ((err = km->ops->check(km)) != 0)
    moan("key %s fails check: %s", d.buf, err);
  if (sk) {
    dstr_reset(&d);
    key_fulltag(sk, &d);
    s = getsig(sk, "ccsig", 1);
    if ((err = s->ops->check(s)) != 0)
      moan("key %s fails check: %s", d.buf, err);
  }

  /* --- Build the header chunk --- */

  dstr_reset(&d);
  dstr_ensure(&d, 256);
  buf_init(&b, d.buf, 256);
  buf_putu32(&b, k->id);
  if (sk) buf_putu32(&b, sk->id);
  assert(BOK(&b));
  chunk_write(e, &b);

  /* --- Build the KEM chunk --- */

  dstr_reset(&d);
  if (setupkem(km, &d, &cx, &c, &m))
    die(EXIT_FAILURE, "failed to encapsulate key");
  buf_init(&b, d.buf, d.len);
  BSTEP(&b, d.len);
  chunk_write(e, &b);

  /* --- Write the signature chunk --- */

  if (s) {
    GC_ENCRYPT(cx, 0, bb, 1024);
    GH_HASH(s->h, bb, 1024);
    dstr_reset(&d);
    if ((en = s->ops->doit(s, &d)) != 0)
      die(EXIT_FAILURE, "error creating signature: %s", key_strerror(en));
    buf_init(&b, d.buf, d.len);
    BSTEP(&b, d.len);
    chunk_write(e, &b);
  }  

  /* --- Now do the main crypto --- */

  assert(GC_CLASS(c)->blksz <= sizeof(bb));
  dstr_ensure(&d, sizeof(bb) + GM_CLASS(m)->hashsz);
  seq = 0;
  for (;;) {
    h = GM_INIT(m);
    GH_HASHU32(h, seq);
    seq++;
    if (GC_CLASS(c)->blksz) {
      GC_ENCRYPT(cx, 0, bb, GC_CLASS(c)->blksz);
      GC_SETIV(c, bb);
    }
    n = fread(bb, 1, sizeof(bb), fp);
    if (!n) break;
    buf_init(&b, d.buf, d.sz);
    tag = buf_get(&b, GM_CLASS(m)->hashsz);
    ct = buf_get(&b, n);
    assert(tag); assert(ct);
    GC_ENCRYPT(c, bb, ct, n);
    GH_HASH(h, ct, n);
    GH_DONE(h, tag);
    GH_DESTROY(h);
    chunk_write(e, &b);
  }

  /* --- Final terminator packet --- */

  buf_init(&b, d.buf, d.sz);
  tag = buf_get(&b, GM_CLASS(m)->hashsz);
  assert(tag);
  GH_DONE(h, tag);
  GH_DESTROY(h);
  chunk_write(e, &b);

  /* --- All done --- */

  e->ops->encdone(e);
  GM_DESTROY(m);
  GC_DESTROY(c);
  GC_DESTROY(cx);
  freeenc(e);
  if (s) freesig(s);
  freekem(km);
  if (fp != stdin) fclose(fp);
  if (of) fclose(ofp);
  key_close(&kf);
  dstr_destroy(&d);
  return (0);

#undef f_bogus
}

/*---- Decryption ---------------------------------------------------------*/

static int decrypt(int argc, char *argv[])
{
  const char *of = 0;
  FILE *ofp = 0, *rfp = 0;
  FILE *fp = 0;
  const char *ef = "binary";
  int i;
  size_t n;
  dstr d = DSTR_INIT;
  buf b;
  key_file kf;
  size_t seq;
  uint32 id;
  key *k;
  key *sk = 0;
  kem *km;
  sig *s = 0;
  gcipher *cx;
  gcipher *c;
  ghash *h;
  gmac *m;
  octet *tag;
  unsigned f = 0;
  const encops *eo;
  const char *err;
  int verb = 1;
  enc *e;

#define f_bogus 1u
#define f_buffer 2u

  for (;;) {
    static const struct option opt[] = {
      { "armour",	0,		0,	'a' },
      { "armor",	0,		0,	'a' },
      { "buffer",	0,		0,	'b' },
      { "verbose",	0,		0,	'v' },
      { "quiet",	0,		0,	'q' },
      { "format", 	OPTF_ARGREQ,	0,	'f' },
      { "output", 	OPTF_ARGREQ,	0,	'o' },
      { 0,		0,		0,	0 }
    };
    i = mdwopt(argc, argv, "abf:o:qv", opt, 0, 0, 0);
    if (i < 0) break;
    switch (i) {
      case 'a': ef = "pem"; break;
      case 'b': f |= f_buffer; break;
      case 'v': verb++; break;
      case 'q': if (verb) verb--; break;
      case 'f': ef = optarg; break;
      case 'o': of = optarg; break;
      default: f |= f_bogus; break;
    }
  }
  if (argc - optind > 1 || (f & f_bogus))
    die(EXIT_FAILURE, "Usage: decrypt [-OPTIONS] [FILE]");

  if ((eo = getenc(ef)) == 0)
    die(EXIT_FAILURE, "encoding `%s' not found", ef);

  if (optind == argc)
    fp = stdin;
  else if (strcmp(argv[optind], "-") == 0) {
    fp = stdin;
    optind++;
  } else if ((fp = fopen(argv[optind], eo->rmode)) == 0) {
    die(EXIT_FAILURE, "couldn't open file `%s': %s",
	argv[optind], strerror(errno));
  } else
    optind++;

  if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0))
    die(EXIT_FAILURE, "can't open keyring `%s'", keyring);

  e = initdec(eo, fp, checkbdry, "CATCRYPT ENCRYPTED MESSAGE");

  /* --- Read the header chunk --- */

  chunk_read(e, &d, &b);
  if (buf_getu32(&b, &id)) {
    if (verb) printf("FAIL malformed header: missing keyid\n");
    exit(EXIT_FAILURE);
  }
  if ((k = key_byid(&kf, id)) == 0) {
    if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
    exit(EXIT_FAILURE);
  }
  if (BLEFT(&b)) {
    if (buf_getu32(&b, &id)) {
      if (verb) printf("FAIL malformed header: missing signature keyid\n");
      exit(EXIT_FAILURE);
    }
    if ((sk = key_byid(&kf, id)) == 0) {
      if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
      exit(EXIT_FAILURE);
    }
  }
  if (BLEFT(&b)) {
    if (verb) printf("FAIL malformed header: junk at end\n");
    exit(EXIT_FAILURE);
  }

  /* --- Find the key --- */

  km = getkem(k, "cckem", 1);

  /* --- Read the KEM chunk --- */

  chunk_read(e, &d, &b);
  if (setupkem(km, &d, &cx, &c, &m)) {
    if (verb) printf("FAIL failed to decapsulate key\n");
    exit(EXIT_FAILURE);
  }

  /* --- Verify the signature, if there is one --- */

  if (sk) {
    s = getsig(sk, "ccsig", 0);
    dstr_reset(&d);
    key_fulltag(sk, &d);
    if (verb && (err = s->ops->check(s)) != 0)
      printf("WARN verification key %s fails check: %s\n", d.buf, err);
    dstr_reset(&d);
    dstr_ensure(&d, 1024);
    GC_ENCRYPT(cx, 0, d.buf, 1024);
    GH_HASH(s->h, d.buf, 1024);
    chunk_read(e, &d, &b);
    if (s->ops->doit(s, &d)) {
      if (verb) printf("FAIL signature verification failed\n");
      exit(EXIT_FAILURE);
    }
    if (verb) {
      dstr_reset(&d);
      key_fulltag(sk, &d);
      printf("INFO good-signature %s\n", d.buf);
    }
    freesig(s);
  } else if (verb)
    printf("INFO no-signature\n");

  /* --- Now decrypt the main body --- */

  if (!of || strcmp(of, "-") == 0) {
    ofp = stdout;
    f |= f_buffer;
  }
  if (!(f & f_buffer)) {
    if ((ofp = fopen(of, "wb")) == 0) {
      die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
	  ofp, strerror(errno));
    }
    rfp = ofp;
  } else if ((rfp = tmpfile()) == 0)
    die(EXIT_FAILURE, "couldn't create temporary file: %s", strerror(errno));

  seq = 0;
  dstr_ensure(&d, GC_CLASS(c)->blksz);
  dstr_ensure(&d, 4);
  for (;;) {
    if (GC_CLASS(c)->blksz) {
      GC_ENCRYPT(cx, 0, d.buf, GC_CLASS(c)->blksz);
      GC_SETIV(c, d.buf);
    }
    h = GM_INIT(m);
    GH_HASHU32(h, seq);
    seq++;
    chunk_read(e, &d, &b);
    if ((tag = buf_get(&b, GM_CLASS(m)->hashsz)) == 0) {
      if (verb) printf("FAIL bad ciphertext chunk: no tag\n");
      exit(EXIT_FAILURE);
    }
    GH_HASH(h, BCUR(&b), BLEFT(&b));
    if (memcmp(tag, GH_DONE(h, 0), GM_CLASS(m)->hashsz) != 0) {
      if (verb)
	printf("FAIL bad ciphertext chunk: authentication failure\n");
      exit(EXIT_FAILURE);
    }
    GH_DESTROY(h);
    if (!BLEFT(&b))
      break;
    GC_DECRYPT(c, BCUR(&b), BCUR(&b), BLEFT(&b));
    if (fwrite(BCUR(&b), 1, BLEFT(&b), rfp) != BLEFT(&b)) {
      if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
      exit(EXIT_FAILURE);
    }
  }

  if (fflush(rfp) || ferror(rfp)) {
    if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
    exit(EXIT_FAILURE);
  }
  if (f & f_buffer) {
    if (!ofp && (ofp = fopen(of, "wb")) == 0) {
      die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
	  of, strerror(errno));
    }
    rewind(rfp);
    dstr_reset(&d);
    dstr_ensure(&d, 65536);
    if (verb && ofp == stdout) printf("DATA\n");
    for (;;) {
      n = fread(d.buf, 1, d.sz, rfp);
      if (!n) break;
      if (fwrite(d.buf, 1, n, ofp) < n)
	die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
    }
    if (ferror(rfp) || fclose(rfp))
      die(EXIT_FAILURE, "error unbuffering output: %s", strerror(errno));
  }
  if (ofp && (fflush(ofp) || ferror(ofp) || fclose(ofp)))
      die(EXIT_FAILURE, "error writing output: %s", strerror(errno));    

  e->ops->decdone(e);
  if (verb && ofp != stdout)
    printf("OK decrypted successfully\n");
  freeenc(e);
  GC_DESTROY(c);
  GC_DESTROY(cx);
  GM_DESTROY(m);
  freekem(km);
  if (fp != stdin) fclose(fp);
  if (of) fclose(ofp);
  key_close(&kf);
  dstr_destroy(&d);
  return (0);

#undef f_bogus
#undef f_buffer
}

/*----- Main code ---------------------------------------------------------*/

#define LISTS(LI)							\
  LI("Lists", list,							\
     listtab[i].name, listtab[i].name)					\
  LI("Key-encapsulation mechanisms", kem,				\
     kemtab[i].name, kemtab[i].name)					\
  LI("Signature schemes", sig,						\
     sigtab[i].name, sigtab[i].name)					\
  LI("Encodings", enc,							\
     enctab[i].name, enctab[i].name)					\
  LI("Symmetric encryption algorithms", cipher,				\
     gciphertab[i], gciphertab[i]->name)				\
  LI("Hash functions", hash,						\
     ghashtab[i], ghashtab[i]->name)					\
  LI("Message authentication codes", mac,				\
     gmactab[i], gmactab[i]->name)

MAKELISTTAB(listtab, LISTS)

int cmd_show(int argc, char *argv[])
{
  return (displaylists(listtab, argv + 1));
}

static int cmd_help(int, char **);

static cmd cmdtab[] = {
  { "help", cmd_help, "help [COMMAND...]" },
  { "show", cmd_show, "show [ITEM...]" },
  CMD_ENCODE,
  CMD_DECODE,
  { "encrypt", encrypt,
    "encrypt [-a] [-k TAG] [-s TAG] [-f FORMAT]\n\t\
[-o OUTPUT] [FILE]", "\
Options:\n\
\n\
-a, --armour		Same as `-f pem'.\n\
-f, --format=FORMAT	Encode as FORMAT.\n\
-k, --key=TAG		Use public encryption key named by TAG.\n\
-s, --sign-key=TAG	Use private signature key named by TAG.\n\
-o, --output=FILE	Write output to FILE.\n\
" },
  { "decrypt", decrypt,
    "decrypt [-abqv] [-f FORMAT] [-o OUTPUT] [FILE]", "\
Options:\n\
\n\
-a, --armour		Same as `-f pem'.\n\
-b, --buffer		Buffer output until we're sure we have it all.\n\
-f, --format=FORMAT	Decode as FORMAT.\n\
-o, --output=FILE	Write output to FILE.\n\
-q, --quiet		Produce fewer messages.\n\
-v, --verbose		Produce more verbose messages.\n\
" }, /* ' emacs is confused */
  { 0, 0, 0 }
};

static int cmd_help(int argc, char **argv)
{
  sc_help(cmdtab, stdout, argv + 1);
  return (0);
}

void version(FILE *fp)
{
  pquis(fp, "$, Catacomb version " VERSION "\n");
}

static void usage(FILE *fp)
{
  pquis(fp, "Usage: $ [-k KEYRING] COMMAND [ARGS]\n");
}

void help_global(FILE *fp)
{
  usage(fp);
  fputs("\n\
Encrypt and decrypt files.\n\
\n\
Global command-line options:\n\
\n\
-h, --help [COMMAND...]	Show this help message, or help for COMMANDs.\n\
-v, --version		Show program version number.\n\
-u, --usage		Show a terse usage message.\n\
\n\
-k, --keyring=FILE	Read keys from FILE.\n",
	fp);
}

/* --- @main@ --- *
 *
 * Arguments:	@int argc@ = number of command line arguments
 *		@char *argv[]@ = vector of command line arguments
 *
 * Returns:	Zero if successful, nonzero otherwise.
 *
 * Use:		Encrypts or decrypts files.
 */

int main(int argc, char *argv[])
{
  unsigned f = 0;

#define f_bogus 1u

  /* --- Initialize the library --- */

  ego(argv[0]);
  sub_init();
  rand_noisesrc(RAND_GLOBAL, &noise_source);
  rand_seed(RAND_GLOBAL, 160);

  /* --- Parse options --- */

  for (;;) {
    static struct option opts[] = {
      { "help",		0,		0,	'h' },
      { "version",	0,		0,	'v' },
      { "usage",	0,		0,	'u' },
      { "keyring",	OPTF_ARGREQ,	0,	'k' },
      { 0,		0,		0,	0 }
    };
    int i = mdwopt(argc, argv, "+hvu k:", opts, 0, 0, 0);
    if (i < 0)
      break;
    switch (i) {
      case 'h':
	sc_help(cmdtab, stdout, argv + optind);
	exit(0);
	break;
      case 'v':
	version(stdout);
	exit(0);
	break;
      case 'u':
	usage(stdout);
	exit(0);
      case 'k':
	keyring = optarg;
	break;
      default:
	f |= f_bogus;
	break;
    }
  }

  argc -= optind;
  argv += optind;
  optind = 0;
  if (f & f_bogus || argc < 1) {
    usage(stderr);
    exit(EXIT_FAILURE);
  }

  /* --- Dispatch to the correct subcommand handler --- */

  return (findcmd(cmdtab, argv[0])->cmd(argc, argv));

#undef f_bogus
}

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
5c3f75ec	1	/* --c--
5c3f75ec	2	*
c65df279	3	* $Id$
5c3f75ec	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
c65df279	53	#include "ectab.h"
	54	#include "ptab.h"
	55
5c3f75ec	56	/----- Utilities ---------------------------------------------------------/
5c3f75ec	57
5c3f75ec	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
38b90111	74	* KEM-specific way to yield a secret hash. The hash is expanded using an
38b90111	75	* MGF (or similar) to make a symmetric encryption and MAC key.
5c3f75ec	76	*
5c3f75ec	77	* If the message is signed, there comes a signature chunk. The signature is
38b90111	78	* on the further output of the MGF. This means that the recipient can
	79	* modify the message and still have a valid signature, so it's not useful
	80	* for proving things to other people; but it also means that the recipient
	81	* knows that the message is from someone who knows the hash, which limits
	82	* the possiblities to (a) whoever encrypted the message (good!) and (b)
	83	* whoever knows the recipient's private key.
5c3f75ec	84	*
	85	* Then come message chunks. Each one begins with a MAC over an implicit
	86	* sequence number and the ciphertext. The final chunk's ciphertext is
	87	* empty; no other chunk is empty. Thus can the correct end-of-file be
	88	* discerned.
	89	*/
	90
	91	/----- Chunk I/O ---------------------------------------------------------/
	92
	93	static void chunk_write(enc e, buf b)
	94	{
	95	octet l[2];
	96	size_t n = BLEN(b);
	97	assert(n <= MASK16);
	98	STORE16(l, n);
	99	if (e->ops->write(e, l, 2) \|\|
	100	e->ops->write(e, BBASE(b), BLEN(b)))
	101	die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
	102	}
	103
	104	static void chunk_read(enc e, dstr d, buf *b)
	105	{
	106	octet l[2];
	107	size_t n;
	108
	109	dstr_reset(d);
	110	errno = 0;
	111	if (e->ops->read(e, l, 2) != 2)
	112	goto err;
	113	n = LOAD16(l);
	114	dstr_ensure(d, n);
	115	if (e->ops->read(e, d->buf, n) != n)
	116	goto err;
	117	d->len = n;
	118	buf_init(b, d->buf, d->len);
	119	return;
	120
	121	err:
	122	if (!errno) die(EXIT_FAILURE, "unexpected end-of-file on input");
	123	else die(EXIT_FAILURE, "error reading input: %s", strerror(errno));
	124	}
	125
	126	/----- Encryption --------------------------------------------------------/
	127
	128	static int encrypt(int argc, char *argv[])
	129	{
c65df279	130	const char of = 0, kn = "ccrypt", *skn = 0;
5c3f75ec	131	FILE *ofp = 0;
	132	FILE *fp = 0;
	133	const char *ef = "binary";
	134	const char *err;
	135	int i;
c65df279	136	int en;
5c3f75ec	137	size_t n;
	138	dstr d = DSTR_INIT;
	139	octet tag, ct;
	140	buf b;
	141	size_t seq;
	142	char bb[16384];
	143	unsigned f = 0;
	144	key_file kf;
	145	key *k;
c65df279	146	key *sk = 0;
5c3f75ec	147	kem *km;
c65df279	148	sig *s = 0;
5c3f75ec	149	gcipher cx, c;
	150	gmac *m;
	151	ghash *h;
	152	const encops *eo;
	153	enc *e;
	154
	155	#define f_bogus 1u
	156
	157	for (;;) {
	158	static const struct option opt[] = {
	159	{ "key", OPTF_ARGREQ, 0, 'k' },
c65df279	160	{ "sign-key", OPTF_ARGREQ, 0, 's' },
5c3f75ec	161	{ "armour", 0, 0, 'a' },
	162	{ "armor", 0, 0, 'a' },
	163	{ "format", OPTF_ARGREQ, 0, 'f' },
	164	{ "output", OPTF_ARGREQ, 0, 'o' },
	165	{ 0, 0, 0, 0 }
	166	};
c65df279	167	i = mdwopt(argc, argv, "k:s:af:o:", opt, 0, 0, 0);
5c3f75ec	168	if (i < 0) break;
	169	switch (i) {
	170	case 'k': kn = optarg; break;
c65df279	171	case 's': skn = optarg; break;
5c3f75ec	172	case 'a': ef = "pem"; break;
	173	case 'f': ef = optarg; break;
	174	case 'o': of = optarg; break;
	175	default: f \|= f_bogus; break;
	176	}
	177	}
	178	if (argc - optind > 1 \|\| (f & f_bogus))
c65df279	179	die(EXIT_FAILURE, "Usage: encrypt [-OPTIONS] [FILE]");
5c3f75ec	180
213e565f	181	if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0))
5c3f75ec	182	die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
	183	if ((k = key_bytag(&kf, kn)) == 0)
	184	die(EXIT_FAILURE, "key `%s' not found", kn);
c65df279	185	if (skn && (sk = key_bytag(&kf, skn)) == 0)
c65df279	186	die(EXIT_FAILURE, "key `%s' not found", skn);
5c3f75ec	187
	188	if ((eo = getenc(ef)) == 0)
	189	die(EXIT_FAILURE, "encoding `%s' not found", ef);
	190
	191	if (optind == argc)
	192	fp = stdin;
	193	else if (strcmp(argv[optind], "-") == 0) {
	194	fp = stdin;
	195	optind++;
	196	} else if ((fp = fopen(argv[optind], "rb")) == 0) {
	197	die(EXIT_FAILURE, "couldn't open file `%s': %s",
	198	argv[optind], strerror(errno));
	199	} else
	200	optind++;
	201
	202	if (!of \|\| strcmp(of, "-") == 0)
	203	ofp = stdout;
	204	else if ((ofp = fopen(of, eo->wmode)) == 0) {
	205	die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
	206	ofp, strerror(errno));
	207	}
	208
c65df279	209	dstr_reset(&d);
5c3f75ec	210	key_fulltag(k, &d);
fa54fe1e	211	e = initenc(eo, ofp, "CATCRYPT ENCRYPTED MESSAGE");
c65df279	212	km = getkem(k, "cckem", 0);
5c3f75ec	213	if ((err = km->ops->check(km)) != 0)
fa54fe1e	214	moan("key %s fails check: %s", d.buf, err);
c65df279	215	if (sk) {
	216	dstr_reset(&d);
	217	key_fulltag(sk, &d);
	218	s = getsig(sk, "ccsig", 1);
	219	if ((err = s->ops->check(s)) != 0)
fa54fe1e	220	moan("key %s fails check: %s", d.buf, err);
c65df279	221	}
5c3f75ec	222
	223	/* --- Build the header chunk --- */
	224
	225	dstr_reset(&d);
	226	dstr_ensure(&d, 256);
	227	buf_init(&b, d.buf, 256);
	228	buf_putu32(&b, k->id);
c65df279	229	if (sk) buf_putu32(&b, sk->id);
5c3f75ec	230	assert(BOK(&b));
	231	chunk_write(e, &b);
	232
	233	/* --- Build the KEM chunk --- */
	234
	235	dstr_reset(&d);
	236	if (setupkem(km, &d, &cx, &c, &m))
	237	die(EXIT_FAILURE, "failed to encapsulate key");
	238	buf_init(&b, d.buf, d.len);
	239	BSTEP(&b, d.len);
	240	chunk_write(e, &b);
	241
c65df279	242	/* --- Write the signature chunk --- */
	243
	244	if (s) {
	245	GC_ENCRYPT(cx, 0, bb, 1024);
	246	GH_HASH(s->h, bb, 1024);
	247	dstr_reset(&d);
	248	if ((en = s->ops->doit(s, &d)) != 0)
	249	die(EXIT_FAILURE, "error creating signature: %s", key_strerror(en));
	250	buf_init(&b, d.buf, d.len);
	251	BSTEP(&b, d.len);
	252	chunk_write(e, &b);
	253	}
	254
5c3f75ec	255	/* --- Now do the main crypto --- */
	256
	257	assert(GC_CLASS(c)->blksz <= sizeof(bb));
	258	dstr_ensure(&d, sizeof(bb) + GM_CLASS(m)->hashsz);
	259	seq = 0;
	260	for (;;) {
	261	h = GM_INIT(m);
dfd1608a	262	GH_HASHU32(h, seq);
5c3f75ec	263	seq++;
	264	if (GC_CLASS(c)->blksz) {
	265	GC_ENCRYPT(cx, 0, bb, GC_CLASS(c)->blksz);
	266	GC_SETIV(c, bb);
	267	}
	268	n = fread(bb, 1, sizeof(bb), fp);
	269	if (!n) break;
	270	buf_init(&b, d.buf, d.sz);
	271	tag = buf_get(&b, GM_CLASS(m)->hashsz);
	272	ct = buf_get(&b, n);
	273	assert(tag); assert(ct);
	274	GC_ENCRYPT(c, bb, ct, n);
	275	GH_HASH(h, ct, n);
	276	GH_DONE(h, tag);
	277	GH_DESTROY(h);
	278	chunk_write(e, &b);
	279	}
	280
	281	/* --- Final terminator packet --- */
	282
	283	buf_init(&b, d.buf, d.sz);
	284	tag = buf_get(&b, GM_CLASS(m)->hashsz);
	285	assert(tag);
	286	GH_DONE(h, tag);
	287	GH_DESTROY(h);
	288	chunk_write(e, &b);
	289
	290	/* --- All done --- */
	291
	292	e->ops->encdone(e);
	293	GM_DESTROY(m);
	294	GC_DESTROY(c);
	295	GC_DESTROY(cx);
	296	freeenc(e);
c65df279	297	if (s) freesig(s);
5c3f75ec	298	freekem(km);
ef13e9a4	299	if (fp != stdin) fclose(fp);
5c3f75ec	300	if (of) fclose(ofp);
	301	key_close(&kf);
	302	dstr_destroy(&d);
	303	return (0);
	304
	305	#undef f_bogus
	306	}
	307
	308	/---- Decryption ---------------------------------------------------------/
	309
	310	static int decrypt(int argc, char *argv[])
	311	{
	312	const char *of = 0;
fa54fe1e	313	FILE ofp = 0, rfp = 0;
5c3f75ec	314	FILE *fp = 0;
	315	const char *ef = "binary";
	316	int i;
fa54fe1e	317	size_t n;
5c3f75ec	318	dstr d = DSTR_INIT;
	319	buf b;
	320	key_file kf;
	321	size_t seq;
	322	uint32 id;
	323	key *k;
c65df279	324	key *sk = 0;
5c3f75ec	325	kem *km;
c65df279	326	sig *s = 0;
5c3f75ec	327	gcipher *cx;
	328	gcipher *c;
	329	ghash *h;
	330	gmac *m;
	331	octet *tag;
	332	unsigned f = 0;
	333	const encops *eo;
c65df279	334	const char *err;
c65df279	335	int verb = 1;
5c3f75ec	336	enc *e;
	337
	338	#define f_bogus 1u
fa54fe1e	339	#define f_buffer 2u
5c3f75ec	340
	341	for (;;) {
	342	static const struct option opt[] = {
	343	{ "armour", 0, 0, 'a' },
	344	{ "armor", 0, 0, 'a' },
fa54fe1e	345	{ "buffer", 0, 0, 'b' },
c65df279	346	{ "verbose", 0, 0, 'v' },
c65df279	347	{ "quiet", 0, 0, 'q' },
5c3f75ec	348	{ "format", OPTF_ARGREQ, 0, 'f' },
	349	{ "output", OPTF_ARGREQ, 0, 'o' },
	350	{ 0, 0, 0, 0 }
	351	};
64459c98	352	i = mdwopt(argc, argv, "abf:o:qv", opt, 0, 0, 0);
5c3f75ec	353	if (i < 0) break;
	354	switch (i) {
	355	case 'a': ef = "pem"; break;
fa54fe1e	356	case 'b': f \|= f_buffer; break;
c65df279	357	case 'v': verb++; break;
c65df279	358	case 'q': if (verb) verb--; break;
5c3f75ec	359	case 'f': ef = optarg; break;
	360	case 'o': of = optarg; break;
	361	default: f \|= f_bogus; break;
	362	}
	363	}
	364	if (argc - optind > 1 \|\| (f & f_bogus))
c65df279	365	die(EXIT_FAILURE, "Usage: decrypt [-OPTIONS] [FILE]");
5c3f75ec	366
	367	if ((eo = getenc(ef)) == 0)
	368	die(EXIT_FAILURE, "encoding `%s' not found", ef);
	369
	370	if (optind == argc)
	371	fp = stdin;
	372	else if (strcmp(argv[optind], "-") == 0) {
	373	fp = stdin;
	374	optind++;
	375	} else if ((fp = fopen(argv[optind], eo->rmode)) == 0) {
	376	die(EXIT_FAILURE, "couldn't open file `%s': %s",
	377	argv[optind], strerror(errno));
	378	} else
	379	optind++;
	380
213e565f	381	if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0))
5c3f75ec	382	die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
5c3f75ec	383
fa54fe1e	384	e = initdec(eo, fp, checkbdry, "CATCRYPT ENCRYPTED MESSAGE");
5c3f75ec	385
	386	/* --- Read the header chunk --- */
	387
	388	chunk_read(e, &d, &b);
c65df279	389	if (buf_getu32(&b, &id)) {
	390	if (verb) printf("FAIL malformed header: missing keyid\n");
	391	exit(EXIT_FAILURE);
	392	}
	393	if ((k = key_byid(&kf, id)) == 0) {
	394	if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
	395	exit(EXIT_FAILURE);
	396	}
	397	if (BLEFT(&b)) {
	398	if (buf_getu32(&b, &id)) {
	399	if (verb) printf("FAIL malformed header: missing signature keyid\n");
	400	exit(EXIT_FAILURE);
	401	}
	402	if ((sk = key_byid(&kf, id)) == 0) {
	403	if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
	404	exit(EXIT_FAILURE);
	405	}
	406	}
	407	if (BLEFT(&b)) {
	408	if (verb) printf("FAIL malformed header: junk at end\n");
	409	exit(EXIT_FAILURE);
	410	}
5c3f75ec	411
	412	/* --- Find the key --- */
	413
c65df279	414	km = getkem(k, "cckem", 1);
5c3f75ec	415
	416	/* --- Read the KEM chunk --- */
	417
	418	chunk_read(e, &d, &b);
c65df279	419	if (setupkem(km, &d, &cx, &c, &m)) {
	420	if (verb) printf("FAIL failed to decapsulate key\n");
	421	exit(EXIT_FAILURE);
	422	}
	423
	424	/* --- Verify the signature, if there is one --- */
	425
	426	if (sk) {
	427	s = getsig(sk, "ccsig", 0);
	428	dstr_reset(&d);
	429	key_fulltag(sk, &d);
	430	if (verb && (err = s->ops->check(s)) != 0)
	431	printf("WARN verification key %s fails check: %s\n", d.buf, err);
	432	dstr_reset(&d);
	433	dstr_ensure(&d, 1024);
	434	GC_ENCRYPT(cx, 0, d.buf, 1024);
	435	GH_HASH(s->h, d.buf, 1024);
	436	chunk_read(e, &d, &b);
	437	if (s->ops->doit(s, &d)) {
	438	if (verb) printf("FAIL signature verification failed\n");
	439	exit(EXIT_FAILURE);
	440	}
	441	if (verb) {
	442	dstr_reset(&d);
	443	key_fulltag(sk, &d);
fa54fe1e	444	printf("INFO good-signature %s\n", d.buf);
c65df279	445	}
ef13e9a4	446	freesig(s);
c65df279	447	} else if (verb)
fa54fe1e	448	printf("INFO no-signature\n");
5c3f75ec	449
	450	/* --- Now decrypt the main body --- */
	451
c65df279	452	if (!of \|\| strcmp(of, "-") == 0) {
5c3f75ec	453	ofp = stdout;
fa54fe1e	454	f \|= f_buffer;
5c3f75ec	455	}
fa54fe1e	456	if (!(f & f_buffer)) {
	457	if ((ofp = fopen(of, "wb")) == 0) {
	458	die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
	459	ofp, strerror(errno));
	460	}
	461	rfp = ofp;
	462	} else if ((rfp = tmpfile()) == 0)
	463	die(EXIT_FAILURE, "couldn't create temporary file: %s", strerror(errno));
5c3f75ec	464
	465	seq = 0;
	466	dstr_ensure(&d, GC_CLASS(c)->blksz);
	467	dstr_ensure(&d, 4);
	468	for (;;) {
	469	if (GC_CLASS(c)->blksz) {
	470	GC_ENCRYPT(cx, 0, d.buf, GC_CLASS(c)->blksz);
	471	GC_SETIV(c, d.buf);
	472	}
	473	h = GM_INIT(m);
dfd1608a	474	GH_HASHU32(h, seq);
5c3f75ec	475	seq++;
5c3f75ec	476	chunk_read(e, &d, &b);
c65df279	477	if ((tag = buf_get(&b, GM_CLASS(m)->hashsz)) == 0) {
fa54fe1e	478	if (verb) printf("FAIL bad ciphertext chunk: no tag\n");
c65df279	479	exit(EXIT_FAILURE);
c65df279	480	}
5c3f75ec	481	GH_HASH(h, BCUR(&b), BLEFT(&b));
c65df279	482	if (memcmp(tag, GH_DONE(h, 0), GM_CLASS(m)->hashsz) != 0) {
c65df279	483	if (verb)
fa54fe1e	484	printf("FAIL bad ciphertext chunk: authentication failure\n");
c65df279	485	exit(EXIT_FAILURE);
c65df279	486	}
ef13e9a4	487	GH_DESTROY(h);
5c3f75ec	488	if (!BLEFT(&b))
	489	break;
	490	GC_DECRYPT(c, BCUR(&b), BCUR(&b), BLEFT(&b));
fa54fe1e	491	if (fwrite(BCUR(&b), 1, BLEFT(&b), rfp) != BLEFT(&b)) {
fa54fe1e	492	if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
c65df279	493	exit(EXIT_FAILURE);
	494	}
	495	}
	496
fa54fe1e	497	if (fflush(rfp) \|\| ferror(rfp)) {
fa54fe1e	498	if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
c65df279	499	exit(EXIT_FAILURE);
5c3f75ec	500	}
fa54fe1e	501	if (f & f_buffer) {
	502	if (!ofp && (ofp = fopen(of, "wb")) == 0) {
	503	die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
	504	of, strerror(errno));
	505	}
	506	rewind(rfp);
	507	dstr_reset(&d);
	508	dstr_ensure(&d, 65536);
64459c98	509	if (verb && ofp == stdout) printf("DATA\n");
fa54fe1e	510	for (;;) {
	511	n = fread(d.buf, 1, d.sz, rfp);
	512	if (!n) break;
	513	if (fwrite(d.buf, 1, n, ofp) < n)
	514	die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
	515	}
	516	if (ferror(rfp) \|\| fclose(rfp))
	517	die(EXIT_FAILURE, "error unbuffering output: %s", strerror(errno));
	518	}
	519	if (ofp && (fflush(ofp) \|\| ferror(ofp) \|\| fclose(ofp)))
	520	die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
5c3f75ec	521
5c3f75ec	522	e->ops->decdone(e);
c65df279	523	if (verb && ofp != stdout)
c65df279	524	printf("OK decrypted successfully\n");
5c3f75ec	525	freeenc(e);
	526	GC_DESTROY(c);
	527	GC_DESTROY(cx);
	528	GM_DESTROY(m);
	529	freekem(km);
ef13e9a4	530	if (fp != stdin) fclose(fp);
5c3f75ec	531	if (of) fclose(ofp);
	532	key_close(&kf);
	533	dstr_destroy(&d);
	534	return (0);
	535
	536	#undef f_bogus
fa54fe1e	537	#undef f_buffer
5c3f75ec	538	}
	539
	540	/----- Main code ---------------------------------------------------------/
	541
c65df279	542	#define LISTS(LI) \
	543	LI("Lists", list, \
	544	listtab[i].name, listtab[i].name) \
	545	LI("Key-encapsulation mechanisms", kem, \
	546	kemtab[i].name, kemtab[i].name) \
	547	LI("Signature schemes", sig, \
	548	sigtab[i].name, sigtab[i].name) \
	549	LI("Encodings", enc, \
	550	enctab[i].name, enctab[i].name) \
	551	LI("Symmetric encryption algorithms", cipher, \
	552	gciphertab[i], gciphertab[i]->name) \
	553	LI("Hash functions", hash, \
	554	ghashtab[i], ghashtab[i]->name) \
	555	LI("Message authentication codes", mac, \
	556	gmactab[i], gmactab[i]->name)
	557
	558	MAKELISTTAB(listtab, LISTS)
	559
	560	int cmd_show(int argc, char *argv[])
	561	{
	562	return (displaylists(listtab, argv + 1));
	563	}
	564
	565	static int cmd_help(int, char **);
5c3f75ec	566
5c3f75ec	567	static cmd cmdtab[] = {
c65df279	568	{ "help", cmd_help, "help [COMMAND...]" },
c65df279	569	{ "show", cmd_show, "show [ITEM...]" },
fa54fe1e	570	CMD_ENCODE,
fa54fe1e	571	CMD_DECODE,
5c3f75ec	572	{ "encrypt", encrypt,
c65df279	573	"encrypt [-a] [-k TAG] [-s TAG] [-f FORMAT]\n\t\
c65df279	574	[-o OUTPUT] [FILE]", "\
5c3f75ec	575	Options:\n\
	576	\n\
	577	-a, --armour Same as `-f pem'.\n\
	578	-f, --format=FORMAT Encode as FORMAT.\n\
c65df279	579	-k, --key=TAG Use public encryption key named by TAG.\n\
c65df279	580	-s, --sign-key=TAG Use private signature key named by TAG.\n\
5c3f75ec	581	-o, --output=FILE Write output to FILE.\n\
	582	" },
	583	{ "decrypt", decrypt,
fa54fe1e	584	"decrypt [-abqv] [-f FORMAT] [-o OUTPUT] [FILE]", "\
5c3f75ec	585	Options:\n\
5c3f75ec	586	\n\
c65df279	587	-a, --armour Same as `-f pem'.\n\
fa54fe1e	588	-b, --buffer Buffer output until we're sure we have it all.\n\
c65df279	589	-f, --format=FORMAT Decode as FORMAT.\n\
5c3f75ec	590	-o, --output=FILE Write output to FILE.\n\
fa54fe1e	591	-q, --quiet Produce fewer messages.\n\
	592	-v, --verbose Produce more verbose messages.\n\
	593	" }, /* ' emacs is confused */
5c3f75ec	594	{ 0, 0, 0 }
	595	};
	596
c65df279	597	static int cmd_help(int argc, char **argv)
5c3f75ec	598	{
c65df279	599	sc_help(cmdtab, stdout, argv + 1);
c65df279	600	return (0);
5c3f75ec	601	}
5c3f75ec	602
c65df279	603	void version(FILE *fp)
5c3f75ec	604	{
	605	pquis(fp, "$, Catacomb version " VERSION "\n");
	606	}
	607
	608	static void usage(FILE *fp)
	609	{
c65df279	610	pquis(fp, "Usage: $ [-k KEYRING] COMMAND [ARGS]\n");
5c3f75ec	611	}
5c3f75ec	612
c65df279	613	void help_global(FILE *fp)
5c3f75ec	614	{
c65df279	615	usage(fp);
c65df279	616	fputs("\n\
ada55141	617	Encrypt and decrypt files.\n\
c65df279	618	\n\
	619	Global command-line options:\n\
	620	\n\
	621	-h, --help [COMMAND...] Show this help message, or help for COMMANDs.\n\
	622	-v, --version Show program version number.\n\
	623	-u, --usage Show a terse usage message.\n\
	624	\n\
	625	-k, --keyring=FILE Read keys from FILE.\n",
	626	fp);
5c3f75ec	627	}
	628
	629	/* --- @main@ --- *
	630	*
	631	* Arguments: @int argc@ = number of command line arguments
	632	* @char *argv[]@ = vector of command line arguments
	633	*
	634	* Returns: Zero if successful, nonzero otherwise.
	635	*
c65df279	636	* Use: Encrypts or decrypts files.
5c3f75ec	637	*/
	638
	639	int main(int argc, char *argv[])
	640	{
	641	unsigned f = 0;
	642
	643	#define f_bogus 1u
	644
	645	/* --- Initialize the library --- */
	646
	647	ego(argv[0]);
	648	sub_init();
	649	rand_noisesrc(RAND_GLOBAL, &noise_source);
	650	rand_seed(RAND_GLOBAL, 160);
	651
	652	/* --- Parse options --- */
	653
	654	for (;;) {
	655	static struct option opts[] = {
	656	{ "help", 0, 0, 'h' },
	657	{ "version", 0, 0, 'v' },
	658	{ "usage", 0, 0, 'u' },
	659	{ "keyring", OPTF_ARGREQ, 0, 'k' },
	660	{ 0, 0, 0, 0 }
	661	};
	662	int i = mdwopt(argc, argv, "+hvu k:", opts, 0, 0, 0);
	663	if (i < 0)
	664	break;
	665	switch (i) {
	666	case 'h':
c65df279	667	sc_help(cmdtab, stdout, argv + optind);
5c3f75ec	668	exit(0);
	669	break;
	670	case 'v':
	671	version(stdout);
	672	exit(0);
	673	break;
	674	case 'u':
	675	usage(stdout);
	676	exit(0);
	677	case 'k':
	678	keyring = optarg;
	679	break;
	680	default:
	681	f \|= f_bogus;
	682	break;
	683	}
	684	}
	685
	686	argc -= optind;
	687	argv += optind;
	688	optind = 0;
	689	if (f & f_bogus \|\| argc < 1) {
	690	usage(stderr);
	691	exit(EXIT_FAILURE);
	692	}
	693
	694	/* --- Dispatch to the correct subcommand handler --- */
	695
c65df279	696	return (findcmd(cmdtab, argv[0])->cmd(argc, argv));
5c3f75ec	697
	698	#undef f_bogus
	699	}
	700
	701	/----- That's all, folks -------------------------------------------------/