X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/b817bfc642225b8c3c0b6a7e42d1fb949b61a606..c65df27983057ec76ed0e72bb370f9a5ae7dad28:/dsig.c

diff --git a/dsig.c b/dsig.c
index 6e624c6..c45d204 100644
--- a/dsig.c
+++ b/dsig.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: dsig.c,v 1.10 2004/04/08 01:36:15 mdw Exp $
+ * $Id$
  *
  * Verify signatures on distribuitions of files
  *
@@ -45,577 +45,12 @@
 #include <mLib/sub.h>
 
 #include "getdate.h"
-#include "grand.h"
+#include "rand.h"
 #include "ghash.h"
 #include "key.h"
 #include "key-data.h"
 #include "noise.h"
-
-#include "ec.h"
-#include "ec-keys.h"
-#include "dh.h"
-#include "gdsa.h"
-#include "gkcdsa.h"
-#include "rsa.h"
-
-#include "sha.h"
-#include "has160.h"
-
-/*----- Algorithm choice --------------------------------------------------*/
-
-/* --- Relevant type operations --- */
-
-typedef struct sig {
-  const struct sigops *ops;
-  key_packdef *kp;
-  ghash *h;
-} sig;
-
-typedef struct sigops {
-  const key_fetchdef *kf;		/* Key fetching structure */
-  size_t kdsz;				/* Size of the key-data structure */
-  sig *(*init)(key */*k*/, void */*kd*/, const gchash */*hc*/);
-  int (*doit)(sig */*s*/, dstr */*d*/);
-  void (*destroy)(sig */*s*/);
-} sigops;
-
-/* --- RSA PKCS1 --- */
-
-typedef struct rsap1_sigctx {
-  sig s;
-  rsa_privctx rp;
-  pkcs1 p1;
-} rsap1_sigctx;
-
-static sig *rsap1_siginit(key *k, void *kd, const gchash *hc)
-{
-  rsap1_sigctx *rs = CREATE(rsap1_sigctx);
-  rsa_privcreate(&rs->rp, kd, &rand_global);
-  rs->p1.r = &rand_global;
-  rs->p1.ep = hc->name;
-  rs->p1.epsz = strlen(hc->name) + 1;
-  rs->s.h = 0;
-  return (&rs->s);
-}
-
-static int rsap1_sigdoit(sig *s, dstr *d)
-{
-  rsap1_sigctx *rs = (rsap1_sigctx *)s;
-  size_t n;
-  mp *m = rsa_sign(&rs->rp, MP_NEW,
-		   GH_DONE(s->h, 0), GH_CLASS(s->h)->hashsz,
-		   pkcs1_sigencode, &rs->p1);
-  if (!m) return (-1);
-  n = mp_octets(rs->rp.rp->n); dstr_ensure(d, n); mp_storeb(m, d->buf, n);
-  d->len += n; mp_drop(m);
-  return (0);
-}
-
-static void rsap1_sigdestroy(sig *s)
-{
-  rsap1_sigctx *rs = (rsap1_sigctx *)s;
-  DESTROY(rs);
-}
-
-static const sigops rsap1_sig = {
-  rsa_privfetch, sizeof(rsa_priv),
-  rsap1_siginit, rsap1_sigdoit, rsap1_sigdestroy
-};
-
-typedef struct rsap1_vrfctx {
-  sig s;
-  rsa_pubctx rp;
-  pkcs1 p1;
-} rsap1_vrfctx;
-
-static sig *rsap1_vrfinit(key *k, void *kd, const gchash *hc)
-{
-  rsap1_vrfctx *rv = CREATE(rsap1_vrfctx);
-  rsa_pubcreate(&rv->rp, kd);
-  rv->p1.r = &rand_global;
-  rv->p1.ep = hc->name;
-  rv->p1.epsz = strlen(hc->name) + 1;
-  rv->s.h = 0;
-  return (&rv->s);
-}
-
-static int rsap1_vrfdoit(sig *s, dstr *d)
-{
-  rsap1_vrfctx *rv = (rsap1_vrfctx *)s;
-  mp *m = mp_loadb(MP_NEW, d->buf, d->len);
-  int rc = rsa_verify(&rv->rp, m,
-		      GH_DONE(s->h, 0), GH_CLASS(s->h)->hashsz,
-		      0, pkcs1_sigdecode, &rv->p1);
-  mp_drop(m);
-  return (rc);
-}
-
-static void rsap1_vrfdestroy(sig *s)
-{
-  rsap1_vrfctx *rv = (rsap1_vrfctx *)s;
-  DESTROY(rv);
-}
-
-static const sigops rsap1_vrf = {
-  rsa_pubfetch, sizeof(rsa_pub),
-  rsap1_vrfinit, rsap1_vrfdoit, rsap1_vrfdestroy
-};
-
-/* --- RSA PSS --- */
-
-static const gccipher *getmgf(key *k, const gchash *hc)
-{
-  dstr d = DSTR_INIT;
-  const gccipher *gc;
-  const char *mm;
-
-  if ((mm = key_getattr(0, k, "mgf-alg")) == 0) {
-    dstr_putf(&d, "%s-mgf", hc->name);
-    mm = d.buf;
-  }
-  if ((gc = gcipher_byname(mm)) == 0)
-    die(EXIT_FAILURE, "unknown encryption scheme `%s'", mm);
-  dstr_destroy(&d);
-  return (gc);
-}
-
-typedef struct rsapss_sigctx {
-  sig s;
-  rsa_privctx rp;
-  pss p;
-} rsapss_sigctx;
-
-static sig *rsapss_siginit(key *k, void *kd, const gchash *hc)
-{
-  rsapss_sigctx *rs = CREATE(rsapss_sigctx);
-  rsa_privcreate(&rs->rp, kd, &rand_global);
-  rs->p.r = &rand_global;
-  rs->p.cc = getmgf(k, hc);
-  rs->p.ch = hc;
-  rs->p.ssz = hc->hashsz;
-  return (&rs->s);
-}
-
-static int rsapss_sigdoit(sig *s, dstr *d)
-{
-  rsapss_sigctx *rs = (rsapss_sigctx *)s;
-  size_t n;
-  mp *m = rsa_sign(&rs->rp, MP_NEW,
-		   GH_DONE(s->h, 0), GH_CLASS(s->h)->hashsz,
-		   pss_encode, &rs->p);
-  if (!m) return (-1);
-  n = mp_octets(rs->rp.rp->n); dstr_ensure(d, n); mp_storeb(m, d->buf, n);
-  d->len += n;  mp_drop(m);
-  return (0);
-}
-
-static void rsapss_sigdestroy(sig *s)
-{
-  rsapss_sigctx *rs = (rsapss_sigctx *)s;
-  DESTROY(rs);
-}
-
-static const sigops rsapss_sig = {
-  rsa_privfetch, sizeof(rsa_priv),
-  rsapss_siginit, rsapss_sigdoit, rsapss_sigdestroy
-};
-
-typedef struct rsapss_vrfctx {
-  sig s;
-  rsa_pubctx rp;
-  pss p;
-} rsapss_vrfctx;
-
-static sig *rsapss_vrfinit(key *k, void *kd, const gchash *hc)
-{
-  rsapss_vrfctx *rv = CREATE(rsapss_vrfctx);
-  rsa_pubcreate(&rv->rp, kd);
-  rv->p.r = &rand_global;
-  rv->p.cc = getmgf(k, hc);
-  rv->p.ch = hc;
-  rv->p.ssz = hc->hashsz;
-  return (&rv->s);
-}
-
-static int rsapss_vrfdoit(sig *s, dstr *d)
-{
-  rsapss_vrfctx *rv = (rsapss_vrfctx *)s;
-  mp *m = mp_loadb(MP_NEW, d->buf, d->len);
-  int rc = rsa_verify(&rv->rp, m,
-		      GH_DONE(s->h, 0), GH_CLASS(s->h)->hashsz,
-		      0, pss_decode, &rv->p);
-  mp_drop(m);
-  return (rc);
-}
-
-static void rsapss_vrfdestroy(sig *s)
-{
-  rsapss_vrfctx *rv = (rsapss_vrfctx *)s;
-  DESTROY(rv);
-}
-
-static const sigops rsapss_vrf = {
-  rsa_pubfetch, sizeof(rsa_pub),
-  rsapss_vrfinit, rsapss_vrfdoit, rsapss_vrfdestroy
-};
-
-/* --- DSA and ECDSA --- */
-
-typedef struct dsa_sigctx {
-  sig s;
-  gdsa g;
-} dsa_sigctx;
-
-static dsa_sigctx *dsa_doinit(key *k, const gprime_param *gp,
-			      mp *y, const gchash *hc)
-{
-  dsa_sigctx *ds = CREATE(dsa_sigctx);
-  dstr t = DSTR_INIT;
-
-  key_fulltag(k, &t);
-  if ((ds->g.g = group_prime(gp)) == 0)
-    die(EXIT_FAILURE, "bad prime group in key `%s'", t.buf);
-  ds->g.u = MP_NEW;
-  ds->g.p = G_CREATE(ds->g.g);
-  if (G_FROMINT(ds->g.g, ds->g.p, y))
-    die(EXIT_FAILURE, "bad public key in key `%s'", t.buf);
-  ds->g.r = &rand_global;
-  ds->g.h = hc;
-  ds->s.h = 0;
-  dstr_destroy(&t);
-  return (ds);
-}
-
-static dsa_sigctx *ecdsa_doinit(key *k, const char *cstr,
-				ec *y, const gchash *hc)
-{
-  dsa_sigctx *ds = CREATE(dsa_sigctx);
-  ec_info ei;
-  const char *e;
-  dstr t = DSTR_INIT;
-
-  key_fulltag(k, &t);
-  if ((e = ec_getinfo(&ei, cstr)) != 0)
-    die(EXIT_FAILURE, "bad curve in key `%s': %s", t.buf, e);
-  ds->g.g = group_ec(&ei);
-  ds->g.u = MP_NEW;
-  ds->g.p = G_CREATE(ds->g.g);
-  if (G_FROMEC(ds->g.g, ds->g.p, y))
-    die(EXIT_FAILURE, "bad public key in key `%s'", t.buf);
-  ds->g.r = &rand_global;
-  ds->g.h = hc;
-  ds->s.h = 0;
-  dstr_destroy(&t);
-  return (ds);
-}
-
-static sig *dsa_siginit(key *k, void *kd, const gchash *hc)
-{
-  dh_priv *dp = kd;
-  dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc);
-  ds->g.u = MP_COPY(dp->x);
-  return (&ds->s);
-}
-
-static sig *ecdsa_siginit(key *k, void *kd, const gchash *hc)
-{
-  ec_priv *ep = kd;
-  dsa_sigctx *ds = ecdsa_doinit(k, ep->cstr, &ep->p, hc);
-  ds->g.u = MP_COPY(ep->x);
-  return (&ds->s);
-}
-
-static int dsa_sigdoit(sig *s, dstr *d)
-{
-  dsa_sigctx *ds = (dsa_sigctx *)s;
-  gdsa_sig ss = GDSA_SIG_INIT;
-  size_t n = mp_octets(ds->g.g->r);
-
-  gdsa_sign(&ds->g, &ss, GH_DONE(ds->s.h, 0), 0);
-  dstr_ensure(d, 2 * n);
-  mp_storeb(ss.r, d->buf, n);
-  mp_storeb(ss.s, d->buf + n, n);
-  d->len += 2 * n;
-  mp_drop(ss.r); mp_drop(ss.s);
-  return (0);
-}
-
-static void dsa_sigdestroy(sig *s)
-{
-  dsa_sigctx *ds = (dsa_sigctx *)s;
-  G_DESTROY(ds->g.g, ds->g.p);
-  mp_drop(ds->g.u);
-  G_DESTROYGROUP(ds->g.g);
-}
-
-static const sigops dsa_sig = {
-  dh_privfetch, sizeof(dh_priv),
-  dsa_siginit, dsa_sigdoit, dsa_sigdestroy
-};
-
-static const sigops ecdsa_sig = {
-  ec_privfetch, sizeof(ec_priv),
-  ecdsa_siginit, dsa_sigdoit, dsa_sigdestroy
-};
-
-static sig *dsa_vrfinit(key *k, void *kd, const gchash *hc)
-{
-  dh_pub *dp = kd;
-  dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc);
-  return (&ds->s);
-}
-
-static sig *ecdsa_vrfinit(key *k, void *kd, const gchash *hc)
-{
-  ec_pub *ep = kd;
-  dsa_sigctx *ds = ecdsa_doinit(k, ep->cstr, &ep->p, hc);
-  return (&ds->s);
-}
-
-static int dsa_vrfdoit(sig *s, dstr *d)
-{
-  dsa_sigctx *ds = (dsa_sigctx *)s;
-  gdsa_sig ss;
-  size_t n = d->len/2;
-  int rc;
-
-  ss.r = mp_loadb(MP_NEW, d->buf, n);
-  ss.s = mp_loadb(MP_NEW, d->buf + n, d->len - n);
-  rc = gdsa_verify(&ds->g, &ss, GH_DONE(ds->s.h, 0));
-  mp_drop(ss.r); mp_drop(ss.s);
-  return (rc);
-}
-
-static const sigops dsa_vrf = {
-  dh_pubfetch, sizeof(dh_pub),
-  dsa_vrfinit, dsa_vrfdoit, dsa_sigdestroy
-};
-
-static const sigops ecdsa_vrf = {
-  ec_pubfetch, sizeof(ec_pub),
-  ecdsa_vrfinit, dsa_vrfdoit, dsa_sigdestroy
-};
-
-/* --- KCDSA and ECKCDSA --- */
-
-static void kcdsa_privkey(dsa_sigctx *ds, mp *x)
-  { ds->g.u = mp_modinv(MP_NEW, x, ds->g.g->r); }
-
-static void kcdsa_sethash(dsa_sigctx *ds, const gchash *hc)
-  { ds->s.h = gkcdsa_beginhash(&ds->g); }
-
-static sig *kcdsa_siginit(key *k, void *kd, const gchash *hc)
-{
-  dh_priv *dp = kd;
-  dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc);
-  kcdsa_privkey(ds, dp->x);
-  kcdsa_sethash(ds, hc);
-  return (&ds->s);
-}
-
-static sig *eckcdsa_siginit(key *k, void *kd, const gchash *hc)
-{
-  ec_priv *ep = kd;
-  dsa_sigctx *ds = ecdsa_doinit(k, ep->cstr, &ep->p, hc);
-  kcdsa_privkey(ds, ep->x);
-  kcdsa_sethash(ds, hc);
-  return (&ds->s);
-}
-
-static int kcdsa_sigdoit(sig *s, dstr *d)
-{
-  dsa_sigctx *ds = (dsa_sigctx *)s;
-  gkcdsa_sig ss = GKCDSA_SIG_INIT;
-  size_t hsz = ds->g.h->hashsz, n = mp_octets(ds->g.g->r);
-
-  gkcdsa_sign(&ds->g, &ss, GH_DONE(ds->s.h, 0), 0);
-  dstr_ensure(d, hsz + n);
-  memcpy(d->buf, ss.r, hsz);
-  mp_storeb(ss.s, d->buf + hsz, n);
-  d->len += hsz + n;
-  xfree(ss.r); mp_drop(ss.s);
-  return (0);
-}
-
-static const sigops kcdsa_sig = {
-  dh_privfetch, sizeof(dh_priv),
-  kcdsa_siginit, kcdsa_sigdoit, dsa_sigdestroy
-};
-
-static const sigops eckcdsa_sig = {
-  ec_privfetch, sizeof(ec_priv),
-  eckcdsa_siginit, kcdsa_sigdoit, dsa_sigdestroy
-};
-
-static sig *kcdsa_vrfinit(key *k, void *kd, const gchash *hc)
-{
-  dh_pub *dp = kd;
-  dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc);
-  kcdsa_sethash(ds, hc);
-  return (&ds->s);
-}
-
-static sig *eckcdsa_vrfinit(key *k, void *kd, const gchash *hc)
-{
-  ec_pub *ep = kd;
-  dsa_sigctx *ds = ecdsa_doinit(k, ep->cstr, &ep->p, hc);
-  kcdsa_sethash(ds, hc);
-  return (&ds->s);
-}
-
-static int kcdsa_vrfdoit(sig *s, dstr *d)
-{
-  dsa_sigctx *ds = (dsa_sigctx *)s;
-  gkcdsa_sig ss;
-  size_t hsz = ds->g.h->hashsz, n = d->len - hsz;
-  int rc;
-
-  if (d->len < hsz)
-    return (-1);
-  ss.r = (octet *)d->buf;
-  ss.s = mp_loadb(MP_NEW, d->buf + hsz, n);
-  rc = gkcdsa_verify(&ds->g, &ss, GH_DONE(ds->s.h, 0));
-  mp_drop(ss.s);
-  return (rc);
-}
-
-static const sigops kcdsa_vrf = {
-  dh_pubfetch, sizeof(dh_pub),
-  kcdsa_vrfinit, kcdsa_vrfdoit, dsa_sigdestroy
-};
-
-static const sigops eckcdsa_vrf = {
-  ec_pubfetch, sizeof(ec_pub),
-  eckcdsa_vrfinit, kcdsa_vrfdoit, dsa_sigdestroy
-};
-
-/* --- The switch table --- */
-
-static const struct sigtab {
-  const char *name;
-  const sigops *signops;
-  const sigops *verifyops;
-  const gchash *ch;
-} sigtab[] = {
-  { "rsapkcs1",	&rsap1_sig,	&rsap1_vrf,	&sha },
-  { "rsapss",	&rsapss_sig,	&rsapss_vrf,	&sha },
-  { "dsa",	&dsa_sig,	&dsa_vrf,	&sha },
-  { "ecdsa",	&ecdsa_sig,	&ecdsa_vrf,	&sha },
-  { "kcdsa",	&kcdsa_sig,	&kcdsa_vrf,	&has160 },
-  { "eckcdsa",	&eckcdsa_sig,	&eckcdsa_vrf,	&has160 },
-  { 0,		0,		0 }
-};
-
-/* --- @getsig@ --- *
- *
- * Arguments:	@key *k@ = the key to load
- *		@int wantpriv@ = nonzero if we want to sign
- *
- * Returns:	A signature-making thing.
- *
- * Use:		Loads a key and starts hashing.
- */
-
-static sig *getsig(key *k, int wantpriv)
-{
-  const char *salg, *halg = 0;
-  dstr d = DSTR_INIT;
-  dstr t = DSTR_INIT;
-  char *p = 0;
-  const char *q;
-  sig *s;
-  const struct sigtab *st;
-  const sigops *so;
-  const gchash *ch;
-  void *kd;
-  int e;
-  key_packdef *kp;
-
-  /* --- Setup stuff --- */
-
-  key_fulltag(k, &t);
-
-  /* --- Get the signature algorithm --- *
-   *
-   * Take the attribute if it's there; otherwise use the key type.
-   */
-
-  if ((q = key_getattr(0, k, "sig-alg")) != 0) {
-    dstr_puts(&d, q);
-    p = d.buf;
-  } else if (strncmp(k->type, "dsig-", 5) == 0 && k->type[5]) {
-    dstr_puts(&d, k->type);
-    p = d.buf + 5;
-  } else
-    die(EXIT_FAILURE, "no signature algorithm for key `%s'", t.buf);
-
-  /* --- Grab the hash algorithm --- *
-   *
-   * Grab it from the signature algorithm if it's there.  But override that
-   * from the attribute.
-   */
-
-  salg = p;
-  if ((p = strchr(p, '-')) != 0) {
-    *p++ = 0;
-    halg = p;
-  }
-  if ((q = key_getattr(0, k, "hash-alg")) != 0)
-    halg = q;
-
-  /* --- Look up the algorithms in the table --- */
-
-  for (st = sigtab; st->name; st++) {
-    if (strcmp(st->name, salg) == 0)
-      goto s_found;
-  }
-  die(EXIT_FAILURE, "signature algorithm `%s' not found in key `%s'",
-      salg, t.buf);
-s_found:;
-  if (!halg)
-    ch = st->ch;
-  else {
-    if ((ch = ghash_byname(halg)) == 0) {
-      die(EXIT_FAILURE, "hash algorithm `%s' not found in key `%s'",
-	  halg, t.buf);
-    }
-  }
-  so = wantpriv ? st->signops : st->verifyops;
-
-  /* --- Load the key --- */
-
-  kd = xmalloc(so->kdsz);
-  kp = key_fetchinit(so->kf, 0, kd);
-  if ((e = key_fetch(kp, k)) != 0)
-    die(EXIT_FAILURE, "error fetching key `%s': %s", t.buf, key_strerror(e));
-  s = so->init(k, kd, ch);
-  if (!s->h)
-    s->h = GH_INIT(ch);
-  s->kp = kp;
-  s->ops = so;
-
-  /* --- Free stuff up --- */
-
-  dstr_destroy(&d);
-  dstr_destroy(&t);
-  return (s);
-}
-
-/* --- @freesig@ --- *
- *
- * Arguments:	@sig *s@ = signature-making thing
- *
- * Returns:	---
- *
- * Use:		Frees up a signature-making thing
- */
-
-static void freesig(sig *s)
-{
-  GH_DESTROY(s->h);
-  key_fetchdone(s->kp);
-  s->ops->destroy(s);
-}
+#include "cc.h"
 
 /*----- Data formatting ---------------------------------------------------*/
 
@@ -1050,8 +485,13 @@ static void blob(block *b, dstr *d)
     case T_DATE:
     case T_EXPIRE:
       DENSURE(d, 8);
-      STORE32(d->buf + d->len, ((b->t & ~MASK32) >> 16) >> 16);
-      STORE32(d->buf + d->len + 4, b->t);
+      if (b->t == KEXP_FOREVER) {
+	STORE32(d->buf + d->len, 0xffffffff);
+	STORE32(d->buf + d->len + 4, 0xffffffff);
+      } else {
+	STORE32(d->buf + d->len, ((b->t & ~MASK32) >> 16) >> 16);
+	STORE32(d->buf + d->len + 4, b->t);
+      }
       d->len += 8;
       break;
     case T_KEYID:
@@ -1221,7 +661,6 @@ static void fhex(FILE *fp, const void *p, size_t sz)
     sz--;
     if (!sz)
       break;
-/*     putc(' ', fp); */
   }
 }    
 
@@ -1243,6 +682,7 @@ static int sign(int argc, char *argv[])
   const char *ifile = 0;
   const char *ofile = 0;
   const char *c = 0;
+  const char *err;
   FILE *ifp, *ofp;
   dstr d = DSTR_INIT;
   block b;
@@ -1261,7 +701,7 @@ static int sign(int argc, char *argv[])
       { "expire",	OPTF_ARGREQ,	0,	'e' },
       { 0,		0,		0,	0 }
     };
-    int i = mdwopt(argc, argv, "+0vqb c: f:o: k:e:", opts, 0, 0, 0);
+    int i = mdwopt(argc, argv, "+0vqb" "c:" "f:o:" "k:e:", opts, 0, 0, 0);
     if (i < 0)
       break;
     switch (i) {
@@ -1302,7 +742,7 @@ static int sign(int argc, char *argv[])
     }
   }
   if (optind != argc || (f & f_bogus))
-    die(EXIT_FAILURE, "Usage: sign [-options]");
+    die(EXIT_FAILURE, "Usage: sign [-OPTIONS]");
 
   /* --- Locate the signing key --- */
 
@@ -1315,7 +755,12 @@ static int sign(int argc, char *argv[])
     die(EXIT_FAILURE, "key `%s' expires: can't create nonexpiring signature",
 	d.buf);
   }
-  s = getsig(k, 1);
+  s = getsig(k, "dsig", 1);
+
+  /* --- Check the key --- */
+
+  if ((err = s->ops->check(s)) != 0)
+    moan("key `%s' fails check: %s", d.buf, err);
 
   /* --- Open files --- */
 
@@ -1452,6 +897,7 @@ static int verify(int argc, char *argv[])
   key *k = 0;
   sig *s;
   dstr d = DSTR_INIT;
+  const char *err;
   FILE *fp;
   block b;
   int e;
@@ -1483,7 +929,7 @@ static int verify(int argc, char *argv[])
   argc -= optind;
   argv += optind;
   if ((f & f_bogus) || argc > 1)
-    die(EXIT_FAILURE, "Usage: verify [-qv] [file]");
+    die(EXIT_FAILURE, "Usage: verify [-qv] [FILE]");
 
   /* --- Open the key file, and start reading the input file --- */
 
@@ -1543,14 +989,16 @@ static int verify(int argc, char *argv[])
 
   /* --- Initialize the hash function and start reading hashed packets --- */
 
-  s = getsig(k, 0);
-
   if (!k) {
     if (verb)
       puts("FAIL no keyid packet found");
     exit(EXIT_FAILURE);
   }
 
+  s = getsig(k, "dsig", 0);
+  if (verb && (err = s->ops->check(s)) != 0)
+    printf("WARN public key fails check: %s", err);
+
   for (;;) {
     switch (e) {
       case T_COMMENT:
@@ -1568,7 +1016,7 @@ static int verify(int argc, char *argv[])
 	break;
       case T_EXPIRE: {
 	time_t now = time(0);
-	if (b.t < now) {
+	if (b.t != KEXP_FOREVER && b.t < now) {
 	  if (verb > 1)
 	    puts("BAD signature has expired");
 	  f |= f_bogus;
@@ -1645,20 +1093,30 @@ done:
 
 /*----- Main code ---------------------------------------------------------*/
 
-typedef struct cmd {
-  const char *name;
-  int (*func)(int /*argc*/, char */*argv*/[]);
-  const char *usage;
-  const char *help;
-} cmd;
+#define LISTS(LI)							\
+  LI("Lists", list,							\
+     listtab[i].name, listtab[i].name)					\
+  LI("Signature schemes", sig,						\
+     sigtab[i].name, sigtab[i].name)					\
+  LI("Hash functions", hash,						\
+     ghashtab[i], ghashtab[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[] = {
-/*   { "manifest", manifest, */
-/*     "manifest [-0] [-o output]" }, */
+  { "help", cmd_help, "help [COMMAND...]" },
+  { "show", cmd_show, "show [ITEM...]" },
   { "sign", sign,
-    "sign [-options]\n\
-	[-0bqv] [-c comment] [-k tag] [-i keyid]\n\
-	[-e expire] [-f file] [-o output]", "\
+    "sign [-0bqv] [-c COMMENT] [-k TAG] [-e EXPIRE]\n\t\
+[-f FILE] [-o OUTPUT]",
+    "\
 Options:\n\
 \n\
 -0, --null		Read null-terminated filenames from stdin.\n\
@@ -1672,7 +1130,7 @@ Options:\n\
 -e, --expire=TIME	The signature should expire after TIME.\n\
 " },
   { "verify", verify,
-    "verify [-qv] [file]", "\
+    "verify [-qv] [FILE]", "\
 Options:\n\
 \n\
 -q, --quiet		Produce fewer messages while working.\n\
@@ -1681,68 +1139,36 @@ Options:\n\
   { 0, 0, 0 }
 };
 
-/* --- @findcmd@ --- *
- *
- * Arguments:	@const char *name@ = a command name
- *
- * Returns:	Pointer to the command structure.
- *
- * Use:		Looks up a command by name.  If the command isn't found, an
- *		error is reported and the program is terminated.
- */
-
-static cmd *findcmd(const char *name)
+static int cmd_help(int argc, char **argv)
 {
-  cmd *c, *chosen = 0;
-  size_t sz = strlen(name);
-
-  for (c = cmdtab; c->name; c++) {
-    if (strncmp(name, c->name, sz) == 0) {
-      if (c->name[sz] == 0) {
-	chosen = c;
-	break;
-      } else if (chosen)
-	die(EXIT_FAILURE, "ambiguous command name `%s'", name);
-      else
-	chosen = c;
-    }
-  }
-  if (!chosen)
-    die(EXIT_FAILURE, "unknown command name `%s'", name);
-  return (chosen);
+  sc_help(cmdtab, stdout, argv + 1);
+  return (0);
 }
 
-static void version(FILE *fp)
+void version(FILE *fp)
 {
   pquis(fp, "$, Catacomb version " VERSION "\n");
 }
 
 static void usage(FILE *fp)
 {
-  pquis(fp, "Usage: $ [-k keyring] command [args]\n");
+  pquis(fp, "Usage: $ [-k KEYRING] COMMAND [ARGS]\n");
 }
 
-static void help(FILE *fp, char **argv)
+void help_global(FILE *fp)
 {
-  cmd *c;
-
-  if (*argv) {
-    c = findcmd(*argv);
-    fprintf(fp, "Usage: %s [-k keyring] %s\n", QUIS, c->usage);
-    if (c->help) {
-      fputc('\n', fp);	
-      fputs(c->help, fp);
-    }
-  } else {
-    version(fp);
-    fputc('\n', fp);
-    usage(fp);
-    fputs("\n\
+  usage(fp);
+  fputs("\n\
 Create and verify signatures on lists of files.\n\
-\n", fp);
-    for (c = cmdtab; c->name; c++)
-      fprintf(fp, "%s\n", c->usage);
-  }
+\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@ --- *
@@ -1784,7 +1210,7 @@ int main(int argc, char *argv[])
       break;
     switch (i) {
       case 'h':
-	help(stdout, argv + optind);
+	sc_help(cmdtab, stdout, argv + optind);
 	exit(0);
 	break;
       case 'v':
@@ -1813,7 +1239,7 @@ int main(int argc, char *argv[])
 
   /* --- Dispatch to the correct subcommand handler --- */
 
-  return (findcmd(argv[0])->func(argc, argv));
+  return (findcmd(cmdtab, argv[0])->cmd(argc, argv));
 
 #undef f_bogus
 }