[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"

/*----- 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 header and key-encapsulation chunks, and 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
#define f_nocheck 2u

  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' },
      { "nocheck",	0,		0,	'C' },
      { 0,		0,		0,	0 }
    };
    i = mdwopt(argc, argv, "k:s:af:o:C", 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;
      case 'C': f |= f_nocheck; 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 (!(f & f_nocheck) && (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));
  if (s) GH_HASHBUF16(s->h, BBASE(&b), BLEN(&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);
  if (s) GH_HASHBUF16(s->h, BBASE(&b), BLEN(&b));
  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
#undef f_nocheck
}

/*---- 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
#define f_nocheck 4u

  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' },
      { "nocheck",	0,		0,	'C' },
      { "format", 	OPTF_ARGREQ,	0,	'f' },
      { "output", 	OPTF_ARGREQ,	0,	'o' },
      { 0,		0,		0,	0 }
    };
    i = mdwopt(argc, argv, "abf:o:qvC", 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 'C': f |= f_nocheck; 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);
  }
  if (sk) {
    s = getsig(sk, "ccsig", 0);
    if (!(f & f_nocheck) && verb && (err = s->ops->check(s)) != 0) {
      dstr_reset(&d);
      key_fulltag(sk, &d);
      printf("WARN verification key %s fails check: %s\n", d.buf, err);
    }
    GH_HASHBUF16(s->h, BBASE(&b), BSZ(&b));
  }

  /* --- 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);
  }
  if (s) GH_HASHBUF16(s->h, d.buf, d.len);

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

  if (sk) {
    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
#undef f_nocheck
}

/*----- 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 [-aC] [-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\
-C, --nocheck		Don't check the public key.\n\
" },
  { "decrypt", decrypt,
    "decrypt [-abqvC] [-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\
-C, --nocheck		Don't check the private key.\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	/----- Static variables --------------------------------------------------/
	57
	58	static const char *keyring = "keyring";
	59
	60	/----- Data format -------------------------------------------------------/
	61
	62	/* --- Overview --- *
	63	*
	64	* The encrypted message is divided into chunks, each preceded by a two-octet
	65	* length. The chunks don't need to be large -- the idea is that we can
	66	* stream the chunks in and out.
	67	*
	68	* The first chunk is a header. It contains the decryption key-id, and maybe
	69	* the verification key-id if the message is signed.
	70	*
	71	* Next comes the key-encapsulation chunk. This is decrypted in some
38b90111	72	* KEM-specific way to yield a secret hash. The hash is expanded using an
38b90111	73	* MGF (or similar) to make a symmetric encryption and MAC key.
5c3f75ec	74	*
5c3f75ec	75	* If the message is signed, there comes a signature chunk. The signature is
f9e51332	76	* on the header and key-encapsulation chunks, and further output of the MGF.
	77	* This means that the recipient can modify the message and still have a
	78	* valid signature, so it's not useful for proving things to other people;
	79	* but it also means that the recipient knows that the message is from
	80	* someone who knows the hash, which limits the possiblities to (a) whoever
	81	* encrypted the message (good!) and (b) whoever knows the recipient's
	82	* private key.
5c3f75ec	83	*
	84	* Then come message chunks. Each one begins with a MAC over an implicit
	85	* sequence number and the ciphertext. The final chunk's ciphertext is
	86	* empty; no other chunk is empty. Thus can the correct end-of-file be
	87	* discerned.
	88	*/
	89
	90	/----- Chunk I/O ---------------------------------------------------------/
	91
	92	static void chunk_write(enc e, buf b)
	93	{
	94	octet l[2];
	95	size_t n = BLEN(b);
	96	assert(n <= MASK16);
	97	STORE16(l, n);
	98	if (e->ops->write(e, l, 2) \|\|
	99	e->ops->write(e, BBASE(b), BLEN(b)))
	100	die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
	101	}
	102
	103	static void chunk_read(enc e, dstr d, buf *b)
	104	{
	105	octet l[2];
	106	size_t n;
	107
	108	dstr_reset(d);
	109	errno = 0;
	110	if (e->ops->read(e, l, 2) != 2)
	111	goto err;
	112	n = LOAD16(l);
	113	dstr_ensure(d, n);
	114	if (e->ops->read(e, d->buf, n) != n)
	115	goto err;
	116	d->len = n;
	117	buf_init(b, d->buf, d->len);
	118	return;
	119
	120	err:
	121	if (!errno) die(EXIT_FAILURE, "unexpected end-of-file on input");
	122	else die(EXIT_FAILURE, "error reading input: %s", strerror(errno));
	123	}
	124
	125	/----- Encryption --------------------------------------------------------/
	126
	127	static int encrypt(int argc, char *argv[])
	128	{
c65df279	129	const char of = 0, kn = "ccrypt", *skn = 0;
5c3f75ec	130	FILE *ofp = 0;
	131	FILE *fp = 0;
	132	const char *ef = "binary";
	133	const char *err;
	134	int i;
c65df279	135	int en;
5c3f75ec	136	size_t n;
	137	dstr d = DSTR_INIT;
	138	octet tag, ct;
	139	buf b;
	140	size_t seq;
	141	char bb[16384];
	142	unsigned f = 0;
	143	key_file kf;
	144	key *k;
c65df279	145	key *sk = 0;
5c3f75ec	146	kem *km;
c65df279	147	sig *s = 0;
5c3f75ec	148	gcipher cx, c;
	149	gmac *m;
	150	ghash *h;
	151	const encops *eo;
	152	enc *e;
	153
	154	#define f_bogus 1u
946c3f72	155	#define f_nocheck 2u
5c3f75ec	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' },
946c3f72	165	{ "nocheck", 0, 0, 'C' },
5c3f75ec	166	{ 0, 0, 0, 0 }
5c3f75ec	167	};
946c3f72	168	i = mdwopt(argc, argv, "k:s:af:o:C", opt, 0, 0, 0);
5c3f75ec	169	if (i < 0) break;
	170	switch (i) {
	171	case 'k': kn = optarg; break;
c65df279	172	case 's': skn = optarg; break;
5c3f75ec	173	case 'a': ef = "pem"; break;
	174	case 'f': ef = optarg; break;
	175	case 'o': of = optarg; break;
946c3f72	176	case 'C': f \|= f_nocheck; break;
5c3f75ec	177	default: f \|= f_bogus; break;
	178	}
	179	}
	180	if (argc - optind > 1 \|\| (f & f_bogus))
c65df279	181	die(EXIT_FAILURE, "Usage: encrypt [-OPTIONS] [FILE]");
5c3f75ec	182
213e565f	183	if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0))
5c3f75ec	184	die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
	185	if ((k = key_bytag(&kf, kn)) == 0)
	186	die(EXIT_FAILURE, "key `%s' not found", kn);
c65df279	187	if (skn && (sk = key_bytag(&kf, skn)) == 0)
c65df279	188	die(EXIT_FAILURE, "key `%s' not found", skn);
5c3f75ec	189
	190	if ((eo = getenc(ef)) == 0)
	191	die(EXIT_FAILURE, "encoding `%s' not found", ef);
	192
	193	if (optind == argc)
	194	fp = stdin;
	195	else if (strcmp(argv[optind], "-") == 0) {
	196	fp = stdin;
	197	optind++;
	198	} else if ((fp = fopen(argv[optind], "rb")) == 0) {
	199	die(EXIT_FAILURE, "couldn't open file `%s': %s",
	200	argv[optind], strerror(errno));
	201	} else
	202	optind++;
	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	ofp, strerror(errno));
	209	}
	210
c65df279	211	dstr_reset(&d);
5c3f75ec	212	key_fulltag(k, &d);
fa54fe1e	213	e = initenc(eo, ofp, "CATCRYPT ENCRYPTED MESSAGE");
c65df279	214	km = getkem(k, "cckem", 0);
946c3f72	215	if (!(f & f_nocheck) && (err = km->ops->check(km)) != 0)
fa54fe1e	216	moan("key %s fails check: %s", d.buf, err);
c65df279	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)
fa54fe1e	222	moan("key %s fails check: %s", d.buf, err);
c65df279	223	}
5c3f75ec	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);
c65df279	231	if (sk) buf_putu32(&b, sk->id);
5c3f75ec	232	assert(BOK(&b));
f9e51332	233	if (s) GH_HASHBUF16(s->h, BBASE(&b), BLEN(&b));
5c3f75ec	234	chunk_write(e, &b);
	235
	236	/* --- Build the KEM chunk --- */
	237
	238	dstr_reset(&d);
	239	if (setupkem(km, &d, &cx, &c, &m))
	240	die(EXIT_FAILURE, "failed to encapsulate key");
	241	buf_init(&b, d.buf, d.len);
	242	BSTEP(&b, d.len);
f9e51332	243	if (s) GH_HASHBUF16(s->h, BBASE(&b), BLEN(&b));
5c3f75ec	244	chunk_write(e, &b);
5c3f75ec	245
c65df279	246	/* --- Write the signature chunk --- */
	247
	248	if (s) {
	249	GC_ENCRYPT(cx, 0, bb, 1024);
	250	GH_HASH(s->h, bb, 1024);
	251	dstr_reset(&d);
	252	if ((en = s->ops->doit(s, &d)) != 0)
	253	die(EXIT_FAILURE, "error creating signature: %s", key_strerror(en));
	254	buf_init(&b, d.buf, d.len);
	255	BSTEP(&b, d.len);
	256	chunk_write(e, &b);
	257	}
	258
5c3f75ec	259	/* --- Now do the main crypto --- */
	260
	261	assert(GC_CLASS(c)->blksz <= sizeof(bb));
	262	dstr_ensure(&d, sizeof(bb) + GM_CLASS(m)->hashsz);
	263	seq = 0;
	264	for (;;) {
	265	h = GM_INIT(m);
dfd1608a	266	GH_HASHU32(h, seq);
5c3f75ec	267	seq++;
	268	if (GC_CLASS(c)->blksz) {
	269	GC_ENCRYPT(cx, 0, bb, GC_CLASS(c)->blksz);
	270	GC_SETIV(c, bb);
	271	}
	272	n = fread(bb, 1, sizeof(bb), fp);
	273	if (!n) break;
	274	buf_init(&b, d.buf, d.sz);
	275	tag = buf_get(&b, GM_CLASS(m)->hashsz);
	276	ct = buf_get(&b, n);
	277	assert(tag); assert(ct);
	278	GC_ENCRYPT(c, bb, ct, n);
	279	GH_HASH(h, ct, n);
	280	GH_DONE(h, tag);
	281	GH_DESTROY(h);
	282	chunk_write(e, &b);
	283	}
	284
	285	/* --- Final terminator packet --- */
	286
	287	buf_init(&b, d.buf, d.sz);
	288	tag = buf_get(&b, GM_CLASS(m)->hashsz);
	289	assert(tag);
	290	GH_DONE(h, tag);
	291	GH_DESTROY(h);
	292	chunk_write(e, &b);
	293
	294	/* --- All done --- */
	295
	296	e->ops->encdone(e);
	297	GM_DESTROY(m);
	298	GC_DESTROY(c);
	299	GC_DESTROY(cx);
	300	freeenc(e);
c65df279	301	if (s) freesig(s);
5c3f75ec	302	freekem(km);
ef13e9a4	303	if (fp != stdin) fclose(fp);
5c3f75ec	304	if (of) fclose(ofp);
	305	key_close(&kf);
	306	dstr_destroy(&d);
	307	return (0);
	308
	309	#undef f_bogus
946c3f72	310	#undef f_nocheck
5c3f75ec	311	}
	312
	313	/---- Decryption ---------------------------------------------------------/
	314
	315	static int decrypt(int argc, char *argv[])
	316	{
	317	const char *of = 0;
fa54fe1e	318	FILE ofp = 0, rfp = 0;
5c3f75ec	319	FILE *fp = 0;
	320	const char *ef = "binary";
	321	int i;
fa54fe1e	322	size_t n;
5c3f75ec	323	dstr d = DSTR_INIT;
	324	buf b;
	325	key_file kf;
	326	size_t seq;
	327	uint32 id;
	328	key *k;
c65df279	329	key *sk = 0;
5c3f75ec	330	kem *km;
c65df279	331	sig *s = 0;
5c3f75ec	332	gcipher *cx;
	333	gcipher *c;
	334	ghash *h;
	335	gmac *m;
	336	octet *tag;
	337	unsigned f = 0;
	338	const encops *eo;
c65df279	339	const char *err;
c65df279	340	int verb = 1;
5c3f75ec	341	enc *e;
	342
	343	#define f_bogus 1u
fa54fe1e	344	#define f_buffer 2u
946c3f72	345	#define f_nocheck 4u
5c3f75ec	346
	347	for (;;) {
	348	static const struct option opt[] = {
	349	{ "armour", 0, 0, 'a' },
	350	{ "armor", 0, 0, 'a' },
fa54fe1e	351	{ "buffer", 0, 0, 'b' },
c65df279	352	{ "verbose", 0, 0, 'v' },
c65df279	353	{ "quiet", 0, 0, 'q' },
946c3f72	354	{ "nocheck", 0, 0, 'C' },
5c3f75ec	355	{ "format", OPTF_ARGREQ, 0, 'f' },
	356	{ "output", OPTF_ARGREQ, 0, 'o' },
	357	{ 0, 0, 0, 0 }
	358	};
946c3f72	359	i = mdwopt(argc, argv, "abf:o:qvC", opt, 0, 0, 0);
5c3f75ec	360	if (i < 0) break;
	361	switch (i) {
	362	case 'a': ef = "pem"; break;
fa54fe1e	363	case 'b': f \|= f_buffer; break;
c65df279	364	case 'v': verb++; break;
c65df279	365	case 'q': if (verb) verb--; break;
946c3f72	366	case 'C': f \|= f_nocheck; break;
5c3f75ec	367	case 'f': ef = optarg; break;
	368	case 'o': of = optarg; break;
	369	default: f \|= f_bogus; break;
	370	}
	371	}
	372	if (argc - optind > 1 \|\| (f & f_bogus))
c65df279	373	die(EXIT_FAILURE, "Usage: decrypt [-OPTIONS] [FILE]");
5c3f75ec	374
	375	if ((eo = getenc(ef)) == 0)
	376	die(EXIT_FAILURE, "encoding `%s' not found", ef);
	377
	378	if (optind == argc)
	379	fp = stdin;
	380	else if (strcmp(argv[optind], "-") == 0) {
	381	fp = stdin;
	382	optind++;
	383	} else if ((fp = fopen(argv[optind], eo->rmode)) == 0) {
	384	die(EXIT_FAILURE, "couldn't open file `%s': %s",
	385	argv[optind], strerror(errno));
	386	} else
	387	optind++;
	388
213e565f	389	if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0))
5c3f75ec	390	die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
5c3f75ec	391
fa54fe1e	392	e = initdec(eo, fp, checkbdry, "CATCRYPT ENCRYPTED MESSAGE");
5c3f75ec	393
	394	/* --- Read the header chunk --- */
	395
	396	chunk_read(e, &d, &b);
c65df279	397	if (buf_getu32(&b, &id)) {
	398	if (verb) printf("FAIL malformed header: missing keyid\n");
	399	exit(EXIT_FAILURE);
	400	}
	401	if ((k = key_byid(&kf, id)) == 0) {
	402	if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
	403	exit(EXIT_FAILURE);
	404	}
	405	if (BLEFT(&b)) {
	406	if (buf_getu32(&b, &id)) {
	407	if (verb) printf("FAIL malformed header: missing signature keyid\n");
	408	exit(EXIT_FAILURE);
	409	}
	410	if ((sk = key_byid(&kf, id)) == 0) {
	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 (verb) printf("FAIL malformed header: junk at end\n");
	417	exit(EXIT_FAILURE);
	418	}
f9e51332	419	if (sk) {
	420	s = getsig(sk, "ccsig", 0);
	421	if (!(f & f_nocheck) && verb && (err = s->ops->check(s)) != 0) {
	422	dstr_reset(&d);
	423	key_fulltag(sk, &d);
	424	printf("WARN verification key %s fails check: %s\n", d.buf, err);
	425	}
	426	GH_HASHBUF16(s->h, BBASE(&b), BSZ(&b));
	427	}
5c3f75ec	428
	429	/* --- Find the key --- */
	430
c65df279	431	km = getkem(k, "cckem", 1);
5c3f75ec	432
	433	/* --- Read the KEM chunk --- */
	434
	435	chunk_read(e, &d, &b);
c65df279	436	if (setupkem(km, &d, &cx, &c, &m)) {
	437	if (verb) printf("FAIL failed to decapsulate key\n");
	438	exit(EXIT_FAILURE);
	439	}
f9e51332	440	if (s) GH_HASHBUF16(s->h, d.buf, d.len);
c65df279	441
	442	/* --- Verify the signature, if there is one --- */
	443
	444	if (sk) {
c65df279	445	dstr_reset(&d);
	446	dstr_ensure(&d, 1024);
	447	GC_ENCRYPT(cx, 0, d.buf, 1024);
	448	GH_HASH(s->h, d.buf, 1024);
	449	chunk_read(e, &d, &b);
	450	if (s->ops->doit(s, &d)) {
	451	if (verb) printf("FAIL signature verification failed\n");
	452	exit(EXIT_FAILURE);
	453	}
	454	if (verb) {
	455	dstr_reset(&d);
	456	key_fulltag(sk, &d);
fa54fe1e	457	printf("INFO good-signature %s\n", d.buf);
c65df279	458	}
ef13e9a4	459	freesig(s);
c65df279	460	} else if (verb)
fa54fe1e	461	printf("INFO no-signature\n");
5c3f75ec	462
	463	/* --- Now decrypt the main body --- */
	464
c65df279	465	if (!of \|\| strcmp(of, "-") == 0) {
5c3f75ec	466	ofp = stdout;
fa54fe1e	467	f \|= f_buffer;
5c3f75ec	468	}
fa54fe1e	469	if (!(f & f_buffer)) {
	470	if ((ofp = fopen(of, "wb")) == 0) {
	471	die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
	472	ofp, strerror(errno));
	473	}
	474	rfp = ofp;
	475	} else if ((rfp = tmpfile()) == 0)
	476	die(EXIT_FAILURE, "couldn't create temporary file: %s", strerror(errno));
5c3f75ec	477
	478	seq = 0;
	479	dstr_ensure(&d, GC_CLASS(c)->blksz);
	480	dstr_ensure(&d, 4);
	481	for (;;) {
	482	if (GC_CLASS(c)->blksz) {
	483	GC_ENCRYPT(cx, 0, d.buf, GC_CLASS(c)->blksz);
	484	GC_SETIV(c, d.buf);
	485	}
	486	h = GM_INIT(m);
dfd1608a	487	GH_HASHU32(h, seq);
5c3f75ec	488	seq++;
5c3f75ec	489	chunk_read(e, &d, &b);
c65df279	490	if ((tag = buf_get(&b, GM_CLASS(m)->hashsz)) == 0) {
fa54fe1e	491	if (verb) printf("FAIL bad ciphertext chunk: no tag\n");
c65df279	492	exit(EXIT_FAILURE);
c65df279	493	}
5c3f75ec	494	GH_HASH(h, BCUR(&b), BLEFT(&b));
c65df279	495	if (memcmp(tag, GH_DONE(h, 0), GM_CLASS(m)->hashsz) != 0) {
c65df279	496	if (verb)
fa54fe1e	497	printf("FAIL bad ciphertext chunk: authentication failure\n");
c65df279	498	exit(EXIT_FAILURE);
c65df279	499	}
ef13e9a4	500	GH_DESTROY(h);
5c3f75ec	501	if (!BLEFT(&b))
	502	break;
	503	GC_DECRYPT(c, BCUR(&b), BCUR(&b), BLEFT(&b));
fa54fe1e	504	if (fwrite(BCUR(&b), 1, BLEFT(&b), rfp) != BLEFT(&b)) {
fa54fe1e	505	if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
c65df279	506	exit(EXIT_FAILURE);
	507	}
	508	}
	509
fa54fe1e	510	if (fflush(rfp) \|\| ferror(rfp)) {
fa54fe1e	511	if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
c65df279	512	exit(EXIT_FAILURE);
5c3f75ec	513	}
fa54fe1e	514	if (f & f_buffer) {
	515	if (!ofp && (ofp = fopen(of, "wb")) == 0) {
	516	die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
	517	of, strerror(errno));
	518	}
	519	rewind(rfp);
	520	dstr_reset(&d);
	521	dstr_ensure(&d, 65536);
64459c98	522	if (verb && ofp == stdout) printf("DATA\n");
fa54fe1e	523	for (;;) {
	524	n = fread(d.buf, 1, d.sz, rfp);
	525	if (!n) break;
	526	if (fwrite(d.buf, 1, n, ofp) < n)
	527	die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
	528	}
	529	if (ferror(rfp) \|\| fclose(rfp))
	530	die(EXIT_FAILURE, "error unbuffering output: %s", strerror(errno));
	531	}
	532	if (ofp && (fflush(ofp) \|\| ferror(ofp) \|\| fclose(ofp)))
	533	die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
5c3f75ec	534
5c3f75ec	535	e->ops->decdone(e);
c65df279	536	if (verb && ofp != stdout)
c65df279	537	printf("OK decrypted successfully\n");
5c3f75ec	538	freeenc(e);
	539	GC_DESTROY(c);
	540	GC_DESTROY(cx);
	541	GM_DESTROY(m);
	542	freekem(km);
ef13e9a4	543	if (fp != stdin) fclose(fp);
5c3f75ec	544	if (of) fclose(ofp);
	545	key_close(&kf);
	546	dstr_destroy(&d);
	547	return (0);
	548
	549	#undef f_bogus
fa54fe1e	550	#undef f_buffer
946c3f72	551	#undef f_nocheck
5c3f75ec	552	}
	553
	554	/----- Main code ---------------------------------------------------------/
	555
c65df279	556	#define LISTS(LI) \
	557	LI("Lists", list, \
	558	listtab[i].name, listtab[i].name) \
	559	LI("Key-encapsulation mechanisms", kem, \
	560	kemtab[i].name, kemtab[i].name) \
	561	LI("Signature schemes", sig, \
	562	sigtab[i].name, sigtab[i].name) \
	563	LI("Encodings", enc, \
	564	enctab[i].name, enctab[i].name) \
	565	LI("Symmetric encryption algorithms", cipher, \
	566	gciphertab[i], gciphertab[i]->name) \
	567	LI("Hash functions", hash, \
	568	ghashtab[i], ghashtab[i]->name) \
	569	LI("Message authentication codes", mac, \
	570	gmactab[i], gmactab[i]->name)
	571
	572	MAKELISTTAB(listtab, LISTS)
	573
	574	int cmd_show(int argc, char *argv[])
	575	{
	576	return (displaylists(listtab, argv + 1));
	577	}
	578
	579	static int cmd_help(int, char **);
5c3f75ec	580
5c3f75ec	581	static cmd cmdtab[] = {
c65df279	582	{ "help", cmd_help, "help [COMMAND...]" },
c65df279	583	{ "show", cmd_show, "show [ITEM...]" },
fa54fe1e	584	CMD_ENCODE,
fa54fe1e	585	CMD_DECODE,
5c3f75ec	586	{ "encrypt", encrypt,
946c3f72	587	"encrypt [-aC] [-k TAG] [-s TAG] [-f FORMAT]\n\t\
c65df279	588	[-o OUTPUT] [FILE]", "\
5c3f75ec	589	Options:\n\
	590	\n\
	591	-a, --armour Same as `-f pem'.\n\
	592	-f, --format=FORMAT Encode as FORMAT.\n\
c65df279	593	-k, --key=TAG Use public encryption key named by TAG.\n\
c65df279	594	-s, --sign-key=TAG Use private signature key named by TAG.\n\
5c3f75ec	595	-o, --output=FILE Write output to FILE.\n\
946c3f72	596	-C, --nocheck Don't check the public key.\n\
5c3f75ec	597	" },
5c3f75ec	598	{ "decrypt", decrypt,
946c3f72	599	"decrypt [-abqvC] [-f FORMAT] [-o OUTPUT] [FILE]", "\
5c3f75ec	600	Options:\n\
5c3f75ec	601	\n\
c65df279	602	-a, --armour Same as `-f pem'.\n\
fa54fe1e	603	-b, --buffer Buffer output until we're sure we have it all.\n\
c65df279	604	-f, --format=FORMAT Decode as FORMAT.\n\
5c3f75ec	605	-o, --output=FILE Write output to FILE.\n\
fa54fe1e	606	-q, --quiet Produce fewer messages.\n\
fa54fe1e	607	-v, --verbose Produce more verbose messages.\n\
946c3f72	608	-C, --nocheck Don't check the private key.\n\
fa54fe1e	609	" }, /* ' emacs is confused */
5c3f75ec	610	{ 0, 0, 0 }
	611	};
	612
c65df279	613	static int cmd_help(int argc, char **argv)
5c3f75ec	614	{
c65df279	615	sc_help(cmdtab, stdout, argv + 1);
c65df279	616	return (0);
5c3f75ec	617	}
5c3f75ec	618
c65df279	619	void version(FILE *fp)
5c3f75ec	620	{
	621	pquis(fp, "$, Catacomb version " VERSION "\n");
	622	}
	623
	624	static void usage(FILE *fp)
	625	{
c65df279	626	pquis(fp, "Usage: $ [-k KEYRING] COMMAND [ARGS]\n");
5c3f75ec	627	}
5c3f75ec	628
c65df279	629	void help_global(FILE *fp)
5c3f75ec	630	{
c65df279	631	usage(fp);
c65df279	632	fputs("\n\
ada55141	633	Encrypt and decrypt files.\n\
c65df279	634	\n\
	635	Global command-line options:\n\
	636	\n\
	637	-h, --help [COMMAND...] Show this help message, or help for COMMANDs.\n\
	638	-v, --version Show program version number.\n\
	639	-u, --usage Show a terse usage message.\n\
	640	\n\
	641	-k, --keyring=FILE Read keys from FILE.\n",
	642	fp);
5c3f75ec	643	}
	644
	645	/* --- @main@ --- *
	646	*
	647	* Arguments: @int argc@ = number of command line arguments
	648	* @char *argv[]@ = vector of command line arguments
	649	*
	650	* Returns: Zero if successful, nonzero otherwise.
	651	*
c65df279	652	* Use: Encrypts or decrypts files.
5c3f75ec	653	*/
	654
	655	int main(int argc, char *argv[])
	656	{
	657	unsigned f = 0;
	658
	659	#define f_bogus 1u
	660
	661	/* --- Initialize the library --- */
	662
	663	ego(argv[0]);
	664	sub_init();
	665	rand_noisesrc(RAND_GLOBAL, &noise_source);
	666	rand_seed(RAND_GLOBAL, 160);
	667
	668	/* --- Parse options --- */
	669
	670	for (;;) {
	671	static struct option opts[] = {
	672	{ "help", 0, 0, 'h' },
	673	{ "version", 0, 0, 'v' },
	674	{ "usage", 0, 0, 'u' },
	675	{ "keyring", OPTF_ARGREQ, 0, 'k' },
	676	{ 0, 0, 0, 0 }
	677	};
	678	int i = mdwopt(argc, argv, "+hvu k:", opts, 0, 0, 0);
	679	if (i < 0)
	680	break;
	681	switch (i) {
	682	case 'h':
c65df279	683	sc_help(cmdtab, stdout, argv + optind);
5c3f75ec	684	exit(0);
	685	break;
	686	case 'v':
	687	version(stdout);
	688	exit(0);
	689	break;
	690	case 'u':
	691	usage(stdout);
	692	exit(0);
	693	case 'k':
	694	keyring = optarg;
	695	break;
	696	default:
	697	f \|= f_bogus;
	698	break;
	699	}
	700	}
	701
	702	argc -= optind;
	703	argv += optind;
	704	optind = 0;
	705	if (f & f_bogus \|\| argc < 1) {
	706	usage(stderr);
	707	exit(EXIT_FAILURE);
	708	}
	709
	710	/* --- Dispatch to the correct subcommand handler --- */
	711
c65df279	712	return (findcmd(cmdtab, argv[0])->cmd(argc, argv));
5c3f75ec	713
	714	#undef f_bogus
	715	}
	716
	717	/----- That's all, folks -------------------------------------------------/