X-Git-Url: https://git.distorted.org.uk/~mdw/tripe/blobdiff_plain/91ac51aa6d078ba287972988fc9cca6593bfbe8f..HEAD:/server/keymgmt.c

diff --git a/server/keymgmt.c b/server/keymgmt.c
index ef4f6a6b..33fa7e21 100644
--- a/server/keymgmt.c
+++ b/server/keymgmt.c
@@ -9,175 +9,30 @@
  *
  * This file is part of Trivial IP Encryption (TrIPE).
  *
- * TrIPE is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * TrIPE is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your
+ * option) any later version.
  *
- * TrIPE 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 General Public License for more details.
+ * TrIPE 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 General Public License
+ * for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with TrIPE; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with TrIPE.  If not, see <https://www.gnu.org/licenses/>.
  */
 
 /*----- Header files ------------------------------------------------------*/
 
 #include "tripe.h"
 
-/*----- Key groups --------------------------------------------------------*/
-
-/* The key-loading functions here must fill in the kdata slot @g@ and
- * either @kpriv@ or @kpub@ as appropriate.  The caller will take care of
- * determining @kpub@ given a private key, and of ensuring that @kpriv@ is
- * null for a public key.
- */
-
-typedef struct kgops {
-  const char *ty;
-  int (*loadpriv)(key_data *, kdata *, dstr *, dstr *);
-  int (*loadpub)(key_data *, kdata *, dstr *, dstr *);
-} kgops;
-
-/* --- Diffie-Hellman --- */
-
-static int kgdh_priv(key_data *d, kdata *kd, dstr *t, dstr *e)
-{
-  key_packstruct kps[DH_PRIVFETCHSZ];
-  key_packdef *kp;
-  dh_priv dp;
-  int rc;
-
-  kp = key_fetchinit(dh_privfetch, kps, &dp);
-  if ((rc = key_unpack(kp, d, t)) != 0) {
-    a_format(e, "unpack-failed", "%s", key_strerror(rc), A_END);
-    goto fail_0;
-  }
-  kd->g = group_prime(&dp.dp);
-  kd->kpriv = MP_COPY(dp.x);
-  rc = 0;
-  goto done;
-fail_0:
-  rc = -1;
-done:
-  key_fetchdone(kp);
-  return (rc);
-}
-
-static int kgdh_pub(key_data *d, kdata *kd, dstr *t, dstr *e)
-{
-  key_packstruct kps[DH_PUBFETCHSZ];
-  key_packdef *kp;
-  dh_pub dp;
-  int rc;
-
-  kp = key_fetchinit(dh_pubfetch, kps, &dp);
-  if ((rc = key_unpack(kp, d, t)) != 0) {
-    a_format(e, "unpack-failed", "%s", key_strerror(rc), A_END);
-    goto fail_0;
-  }
-  kd->g = group_prime(&dp.dp);
-  kd->kpub = G_CREATE(kd->g);
-  if (G_FROMINT(kd->g, kd->kpub, dp.y)) {
-    a_format(e, "bad-public-vector", A_END);
-    goto fail_1;
-  }
-  rc = 0;
-  goto done;
-fail_1:
-  G_DESTROY(kd->g, kd->kpub);
-  G_DESTROYGROUP(kd->g);
-fail_0:
-  rc = -1;
-done:
-  key_fetchdone(kp);
-  return (rc);
-}
-
-static const kgops kgdh_ops = { "dh", kgdh_priv, kgdh_pub };
-
-/* --- Elliptic curve --- */
-
-static int kgec_priv(key_data *d, kdata *kd, dstr *t, dstr *e)
-{
-  key_packstruct kps[EC_PRIVFETCHSZ];
-  key_packdef *kp;
-  ec_priv ep;
-  ec_info ei;
-  const char *err;
-  int rc;
-
-  kp = key_fetchinit(ec_privfetch, kps, &ep);
-  if ((rc = key_unpack(kp, d, t)) != 0) {
-    a_format(e, "unpack-failed", "%s", key_strerror(rc), A_END);
-    goto fail_0;
-  }
-  if ((err = ec_getinfo(&ei, ep.cstr)) != 0) {
-    a_format(e, "decode-failed", "%s", err, A_END);
-    goto fail_0;
-  }
-  kd->g = group_ec(&ei);
-  kd->kpriv = MP_COPY(ep.x);
-  rc = 0;
-  goto done;
-fail_0:
-  rc = -1;
-done:
-  key_fetchdone(kp);
-  return (rc);
-}
-
-static int kgec_pub(key_data *d, kdata *kd, dstr *t, dstr *e)
-{
-  key_packstruct kps[EC_PUBFETCHSZ];
-  key_packdef *kp;
-  ec_pub ep;
-  ec_info ei;
-  const char *err;
-  int rc;
-
-  kp = key_fetchinit(ec_pubfetch, kps, &ep);
-  if ((rc = key_unpack(kp, d, t)) != 0) {
-    a_format(e, "unpack-failed", "%s", key_strerror(rc), A_END);
-    goto fail_0;
-  }
-  if ((err = ec_getinfo(&ei, ep.cstr)) != 0) {
-    a_format(e, "decode-failed", "%s", err, A_END);
-    goto fail_0;
-  }
-  kd->g = group_ec(&ei);
-  kd->kpub = G_CREATE(kd->g);
-  if (G_FROMEC(kd->g, kd->kpub, &ep.p)) {
-    a_format(e, "bad-public-vector", A_END);
-    goto fail_1;
-  }
-  rc = 0;
-  goto done;
-fail_1:
-  G_DESTROY(kd->g, kd->kpub);
-  G_DESTROYGROUP(kd->g);
-fail_0:
-  rc = -1;
-done:
-  key_fetchdone(kp);
-  return (rc);
-}
-
-static const kgops kgec_ops = { "ec", kgec_priv, kgec_pub };
-
-/* --- Table of supported key types --- */
-
-static const kgops *kgtab[] = { &kgdh_ops, &kgec_ops, 0 };
-
 /*----- Algswitch stuff ---------------------------------------------------*/
 
 /* --- @algs_get@ --- *
  *
  * Arguments:	@algswitch *a@ = where to put the algorithms
- *		@dstr *e@ = where to write errror tokens
+ *		@dstr *e@ = where to write error tokens
  *		@key_file *kf@ = key file
  *		@key *k@ = key to inspect
  *
@@ -189,18 +44,10 @@ static const kgops *kgtab[] = { &kgdh_ops, &kgec_ops, 0 };
 static int algs_get(algswitch *a, dstr *e, key_file *kf, key *k)
 {
   const char *p;
-  char *q, *qq;
-  dstr d = DSTR_INIT;
+  const bulkops *bops;
+  dstr d = DSTR_INIT, dd = DSTR_INIT;
   int rc = -1;
 
-  /* --- Symmetric encryption for bulk data --- */
-
-  if ((p = key_getattr(kf, k, "cipher")) == 0) p = "blowfish-cbc";
-  if ((a->c = gcipher_byname(p)) == 0) {
-    a_format(e, "unknown-cipher", "%s", p, A_END);
-    goto done;
-  }
-
   /* --- Hash function --- */
 
   if ((p = key_getattr(kf, k, "hash")) == 0) p = "rmd160";
@@ -221,44 +68,23 @@ static int algs_get(algswitch *a, dstr *e, key_file *kf, key *k)
     goto done;
   }
 
-  /* --- Message authentication for bulk data --- */
+  /* --- Bulk crypto transform --- */
 
-  if ((p = key_getattr(kf, k, "mac")) != 0) {
-    dstr_reset(&d);
-    dstr_puts(&d, p);
-    if ((q = strchr(d.buf, '/')) != 0)
-      *q++ = 0;
-    if ((a->m = gmac_byname(d.buf)) == 0) {
-      a_format(e, "unknown-mac", "%s", d.buf, A_END);
-      goto done;
-    }
-    if (!q)
-      a->tagsz = a->m->hashsz;
-    else {
-      unsigned long n = strtoul(q, &qq, 0);
-      if (*qq)  {
-	a_format(e, "bad-tag-length-string", "%s", q, A_END);
-	goto done;
-      }
-      if (n%8 || n/8 > a->m->hashsz) {
-	a_format(e, "bad-tag-length", "%lu", n, A_END);
-	goto done;
-      }
-      a->tagsz = n/8;
-    }
-  } else {
-    dstr_reset(&d);
-    dstr_putf(&d, "%s-hmac", a->h->name);
-    if ((a->m = gmac_byname(d.buf)) == 0) {
-      a_format(e, "no-hmac-for-hash", "%s", a->h->name, A_END);
-      goto done;
-    }
-    a->tagsz = a->h->hashsz/2;
+  if ((p = key_getattr(kf, k, "bulk")) == 0) p = "v0";
+  for (bops = bulktab; bops->name && strcmp(p, bops->name) != 0; bops++);
+  if (!bops->name) {
+    a_format(e, "unknown-bulk-transform", "%s", p, A_END);
+    goto done;
   }
+  if ((a->bulk = bops->getalgs(a, e, kf, k)) == 0) goto done;
+  a->bulk->ops = bops;
+
+  /* --- All done --- */
 
   rc = 0;
 done:
   dstr_destroy(&d);
+  dstr_destroy(&dd);
   return (rc);
 }
 
@@ -266,7 +92,7 @@ done:
  *
  * Arguments:	@algswitch *a@ = a choice of algorithms
  *		@dstr *e@ = where to write error tokens
- *		@const group *g@ = the group we're working in
+ *		@const dhgrp *grp@ = the group we're working in
  *
  * Returns:	Zero if OK; nonzero on error.
  *
@@ -276,35 +102,9 @@ done:
  *		for use by @keyset@ functions.
  */
 
-static int algs_check(algswitch *a, dstr *e, const group *g)
+static int algs_check(algswitch *a, dstr *e, const dhgrp *grp)
 {
-  /* --- Derive the key sizes --- *
-   *
-   * Must ensure that we have non-empty keys.  This isn't ideal, but it
-   * provides a handy sanity check.  Also must be based on a 64- or 128-bit
-   * block cipher or we can't do the data expiry properly.
-   */
-
   a->hashsz = a->h->hashsz;
-  if ((a->cksz = keysz(a->hashsz, a->c->keysz)) == 0) {
-    a_format(e, "cipher", "%s", a->c->name,
-	     "no-key-size", "%lu", (unsigned long)a->hashsz,
-	     A_END);
-    return (-1);
-  }
-  if ((a->mksz = keysz(a->hashsz, a->m->keysz)) == 0) {
-    a_format(e, "mac", "%s", a->m->name,
-	     "no-key-size", "%lu", (unsigned long)a->hashsz,
-	     A_END);
-    return (-1);
-  }
-
-  /* --- Derive the data limit --- */
-
-  if (a->c->blksz < 16) a->expsz = MEG(64);
-  else a->expsz = MEG(2048);
-
-  /* --- Ensure the MGF accepts hashes as keys --- */
 
   if (keysz(a->hashsz, a->mgf->keysz) != a->hashsz) {
     a_format(e, "mgf", "%s", a->mgf->name,
@@ -313,7 +113,7 @@ static int algs_check(algswitch *a, dstr *e, const group *g)
     return (-1);
   }
 
-  /* --- All ship-shape and Bristol-fashion --- */
+  if (a->bulk->ops->checkalgs(a->bulk, a, e)) return (-1);
 
   return (0);
 }
@@ -332,17 +132,20 @@ int km_samealgsp(const kdata *kdx, const kdata *kdy)
 {
   const algswitch *a = &kdx->algs, *aa = &kdy->algs;
 
-  return (group_samep(kdx->g, kdy->g) && a->c == aa->c &&
+  return (kdx->grp->ops == kdy->grp->ops &&
+	  kdx->grp->ops->samegrpp(kdx->grp, kdy->grp) &&
 	  a->mgf == aa->mgf && a->h == aa->h &&
-	  a->m == aa->m && a->tagsz == aa->tagsz);
+	  a->bulk->ops == aa->bulk->ops &&
+	  a->bulk->ops->samealgsp(a->bulk, aa->bulk));
 }
 
 /*----- Key data and key nodes --------------------------------------------*/
 
 typedef struct keyhalf {
   const char *kind;
-  int (*load)(const kgops *, key_data *, kdata *, dstr *, dstr *);
-  const char *kr;
+  int (*load)(key_file *, key *, key_data *,
+	      const dhops *, kdata *, dstr *, dstr *);
+  char *kr;
   key_file *kf;
   fwatch w;
   sym_table tab;
@@ -350,8 +153,10 @@ typedef struct keyhalf {
 
 /* --- @kh_loadpub@, @kh_loadpriv@ --- *
  *
- * Arguments:	@const kgops *ko@ = key-group operations for key type
- *		@key_data *d@ = key data object as stored in keyring
+ * Arguments:	@const dhops *dh@ = Diffie--Hellman operations for key type
+ *		@key_file *kf@ = key file from which the key was loaded
+ *		@key *k@ = the key object we're loading
+ *		@key_data *d@ = the key data to load
  *		@kdata *kd@ = our key-data object to fill in
  *		@dstr *t@ = the key tag name
  *		@dstr *e@ = a string to write error tokens to
@@ -359,10 +164,10 @@ typedef struct keyhalf {
  * Returns:	Zero on success, @-1@ on error.
  *
  * Use:		These functions handle the main difference between public and
- *		private key halves.  They are responsible for setting @g@,
- *		@kpriv@ and @kpub@ appropriately in all keys, handling the
- *		mismatch between the largely half-indifferent calling code
- *		and the group-specific loading functions.
+ *		private key halves.  They are responsible for setting @grp@,
+ *		@k@ and @K@ appropriately in all keys, handling the mismatch
+ *		between the largely half-indifferent calling code and the
+ *		group-specific loading functions.
  *
  *		The function @kh_loadpriv@ is also responsible for checking
  *		the group for goodness.  We don't bother checking public
@@ -371,46 +176,55 @@ typedef struct keyhalf {
  *		checked.
  */
 
-static int kh_loadpub(const kgops *ko, key_data *d, kdata *kd,
-		      dstr *t, dstr *e)
+static int kh_loadpub(key_file *kf, key *k, key_data *d,
+		      const dhops *dh, kdata *kd, dstr *t, dstr *e)
 {
   int rc;
 
-  if ((rc = ko->loadpub(d, kd, t, e)) != 0)
+  if ((rc = dh->ldpub(kf, k, d, kd, t, e)) != 0)
     goto fail_0;
-  if (group_check(kd->g, kd->kpub)) {
-    a_format(e, "bad-public-group-element");
+  kd->grp->ops = dh;
+  if (kd->grp->ops->checkge(kd->grp, kd->K)) {
+    a_format(e, "bad-public-group-element", A_END);
     goto fail_1;
   }
-  kd->kpriv = 0;
   return (0);
 
 fail_1:
-  G_DESTROY(kd->g, kd->kpub);
-  G_DESTROYGROUP(kd->g);
+  kd->grp->ops->freege(kd->grp, kd->K);
+  kd->grp->ops->freegrp(kd->grp);
 fail_0:
   return (-1);
 }
 
-static int kh_loadpriv(const kgops *ko, key_data *d, kdata *kd,
-		       dstr *t, dstr *e)
+static int kh_loadpriv(key_file *kf, key *k, key_data *d,
+		       const dhops *dh, kdata *kd, dstr *t, dstr *e)
 {
   int rc;
   const char *err;
+  dhge *K;
+  int ok;
 
-  if ((rc = ko->loadpriv(d, kd, t, e)) != 0)
+  if ((rc = dh->ldpriv(kf, k, d, kd, t, e)) != 0)
     goto fail_0;
-  if ((err = G_CHECK(kd->g, &rand_global)) != 0) {
+  kd->grp->ops = dh;
+  if ((err = kd->grp->ops->checkgrp(kd->grp)) != 0) {
     a_format(e, "bad-group", "%s", err, A_END);
     goto fail_1;
   }
-  kd->kpub = G_CREATE(kd->g);
-  G_EXP(kd->g, kd->kpub, kd->g->g, kd->kpriv);
+  K = kd->grp->ops->mul(kd->grp, kd->k, 0);
+  ok = kd->grp->ops->eq(kd->grp, kd->K, K);
+  kd->grp->ops->freege(kd->grp, K);
+  if (!ok) {
+    a_format(e, "incorrect-public-key", A_END);
+    goto fail_1;
+  }
   return (0);
 
 fail_1:
-  mp_drop(kd->kpriv);
-  G_DESTROYGROUP(kd->g);
+  kd->grp->ops->freesc(kd->grp, kd->k);
+  kd->grp->ops->freege(kd->grp, kd->K);
+  kd->grp->ops->freegrp(kd->grp);
 fail_0:
   return (-1);
 }
@@ -461,18 +275,15 @@ static int kh_reopen(keyhalf *kh)
   key_file *kf = CREATE(key_file);
 
   if (key_open(kf, kh->kr, KOPEN_READ, keymoan, kh)) {
-    a_warn("KEYMGMT", "%s-keyring", kh->kind, "%s", kh->kr,
-	   "read-error", "?ERRNO", A_END);
     DESTROY(kf);
     return (-1);
-  } else {
-    if (kh->kf) {
-      key_close(kh->kf);
-      DESTROY(kh->kf);
-    }
-    kh->kf = kf;
-    return (0);
   }
+  if (kh->kf) {
+    key_close(kh->kf);
+    DESTROY(kh->kf);
+  }
+  kh->kf = kf;
+  return (0);
 }
 
 /* --- @kh_init@ --- *
@@ -480,22 +291,21 @@ static int kh_reopen(keyhalf *kh)
  * Arguments:	@keyhalf *kh@ = pointer to keyhalf structure to set up
  *		@const char *kr@ = name of the keyring file
  *
- * Returns:	---
+ * Returns:	Zero on success, @-1@ on error.
  *
  * Use:		Initialize a keyhalf structure, maintaining the private or
  *		public keys.  Intended to be called during initialization:
  *		exits if there's some kind of problem.
  */
 
-static void kh_init(keyhalf *kh, const char *kr)
+static int kh_init(keyhalf *kh, const char *kr)
 {
-  kh->kr = kr;
+  if (kh->kf) return (0);
+  kh->kr = xstrdup(kr);
+  if (kh_reopen(kh)) return (-1);
   fwatch_init(&kh->w, kr);
   sym_create(&kh->tab);
-  kh->kf = 0;
-
-  if (kh_reopen(kh))
-    die(EXIT_FAILURE, "failed to load %s keyring `%s'", kh->kind, kr);
+  return (0);
 }
 
 /* --- @kh_load@ --- *
@@ -522,7 +332,8 @@ static kdata *kh_load(keyhalf *kh, const char *tag, int complainp)
   key_data **d;
   kdata *kd;
   const char *ty;
-  const kgops **ko;
+  const dhops *dh;
+  T( const dhgrp *g; )
 
   /* --- Find the key and grab its tag --- */
 
@@ -545,24 +356,24 @@ static kdata *kh_load(keyhalf *kh, const char *tag, int complainp)
   if (!ty && strncmp(k->type, "tripe-", 6) == 0) ty = k->type + 6;
   if (!ty) ty = "dh";
 
-  for (ko = kgtab; *ko; ko++)
-    if (strcmp((*ko)->ty, ty) == 0) goto foundko;
+  for (dh = dhtab; dh->name; dh++)
+    if (strcmp(dh->name, ty) == 0) goto founddh;
   a_warn("KEYMGMT", "%s-keyring", kh->kind,
 	 "%s", kh->kr, "key", "%s", t.buf,
 	 "unknown-group-type", "%s", ty, A_END);
   goto fail_0;
 
-foundko:
+founddh:
   kd = CREATE(kdata);
-  if (kh->load(*ko, *d, kd, &t, &e)) {
+  if (kh->load(kh->kf, k, *d, dh, kd, &t, &e)) {
     a_warn("KEYMGMT", "%s-keyring", kh->kind,
-	   "%s", kh->kr, "key" "%s", t.buf,
+	   "%s", kh->kr, "key", "%s", t.buf,
 	   "*%s", e.buf, A_END);
     goto fail_1;
   }
 
   if (algs_get(&kd->algs, &e, kh->kf, k) ||
-      (kd->kpriv && algs_check(&kd->algs, &e, kd->g))) {
+      algs_check(&kd->algs, &e, kd->grp)) {
     a_warn("KEYMGMT", "%s-keyring", kh->kind,
 	   "%s", kh->kr, "key", "%s", t.buf,
 	   "*%s", e.buf, A_END);
@@ -570,32 +381,31 @@ foundko:
   }
 
   kd->tag = xstrdup(t.buf);
-  kd->indexsz = mp_octets(kd->g->r);
   kd->ref = 1;
   kd->kn = 0;
+  kd->id = k->id;
   kd->t_exp = k->exp;
 
   IF_TRACING(T_KEYMGMT, {
     trace(T_KEYMGMT, "keymgmt: loaded %s key `%s'", kh->kind, t.buf);
     IF_TRACING(T_CRYPTO, {
-      trace(T_CRYPTO, "crypto: r = %s", mpstr(kd->g->r));
-      trace(T_CRYPTO, "crypto: h = %s", mpstr(kd->g->h));
-      if (kd->kpriv)
-	trace(T_CRYPTO, "crypto: x = %s", mpstr(kd->kpriv));
-      trace(T_CRYPTO, "crypto: cipher = %s", kd->algs.c->name);
-      trace(T_CRYPTO, "crypto: mgf = %s", kd->algs.mgf->name);
-      trace(T_CRYPTO, "crypto: hash = %s", kd->algs.h->name);
-      trace(T_CRYPTO, "crypto: mac = %s/%lu",
-	    kd->algs.m->name, (unsigned long)kd->algs.tagsz * 8);
+      g = kd->grp;
+      g->ops->tracegrp(g);
+      if (kd->k)
+	trace(T_CRYPTO, "crypto: k = %s", g->ops->scstr(g, kd->k));
+      trace(T_CRYPTO, "crypto: K = %s", g->ops->gestr(g, kd->K));
+      trace(T_CRYPTO, "crypto: bulk transform = %s",
+	    kd->algs.bulk->ops->name);
+      kd->algs.bulk->ops->tracealgs(kd->algs.bulk);
     })
   })
 
   goto done;
 
 fail_2:
-  if (kd->kpriv) mp_drop(kd->kpriv);
-  G_DESTROY(kd->g, kd->kpub);
-  G_DESTROYGROUP(kd->g);
+  if (kd->k) kd->grp->ops->freesc(kd->grp, kd->k);
+  kd->grp->ops->freege(kd->grp, kd->K);
+  kd->grp->ops->freegrp(kd->grp);
 fail_1:
   DESTROY(kd);
 fail_0:
@@ -707,7 +517,7 @@ static int kh_refresh(keyhalf *kh)
     kn->f &= ~KNF_BROKEN;
     if (kd->t_exp == kn->kd->t_exp &&
 	km_samealgsp(kd, kn->kd) &&
-	G_EQ(kd->g, kd->kpub, kn->kd->kpub)) {
+	kd->grp->ops->eq(kd->grp, kd->K, kn->kd->K)) {
       T( trace(T_KEYMGMT, "keymgmt: key `%s' unchanged", SYM_NAME(kn)); )
       continue;
     }
@@ -722,10 +532,33 @@ static int kh_refresh(keyhalf *kh)
   return (changep);
 }
 
+/* --- @kh_clear@ --- *
+ *
+ * Arguments:	@keyhalf *kh@ = pointer to keyhalf structure
+ *
+ * Returns:	---
+ *
+ * Use:		Clears out the keyhalf's keyring and flushes the cache.
+ */
+
+static void kh_clear(keyhalf *kh)
+{
+  sym_iter i;
+  knode *kn;
+
+  if (!kh->kf) return;
+  for (sym_mkiter(&i, &kh->tab); (kn = sym_next(&i)) != 0; )
+    if (kn->kd) km_unref(kn->kd);
+  sym_destroy(&kh->tab);
+  key_close(kh->kf);
+  xfree(kh->kr);
+  kh->kf = 0;
+}
+
 /*----- Main code ---------------------------------------------------------*/
 
-const char *tag_priv;
-kdata *master;
+char *tag_priv = 0;
+kdata *master = 0;
 
 /* --- @km_init@ --- *
  *
@@ -733,28 +566,37 @@ kdata *master;
  *		@const char *pubkr@ = public keyring file
  *		@const char *ptag@ = default private-key tag
  *
- * Returns:	---
+ * Returns:	Zero on success, @-1@ on failure.
  *
  * Use:		Initializes the key-management machinery, loading the
  *		keyrings and so on.
  */
 
-void km_init(const char *privkr, const char *pubkr, const char *ptag)
+int km_init(const char *privkr, const char *pubkr, const char *ptag)
 {
   const gchash *const *hh;
+  kdata *kd;
 
   for (hh = ghashtab; *hh; hh++) {
     if ((*hh)->hashsz > MAXHASHSZ) {
-      die(EXIT_FAILURE, "INTERNAL ERROR: %s hash length %lu > MAXHASHSZ %d",
-	  (*hh)->name, (unsigned long)(*hh)->hashsz, MAXHASHSZ);
+      a_warn("ABORT", "hash-size-too-large", "hash",
+	     "%s", (*hh)->name, "size", "%lu", (*hh)->hashsz,
+	     "limit", "%d", MAXHASHSZ, A_END);
+      abort();
     }
   }
 
-  kh_init(&priv, privkr);
-  kh_init(&pub, pubkr);
+  if (kh_init(&priv, privkr) || kh_init(&pub, pubkr))
+    return (-1);
+
+  tag_priv = ptag ? xstrdup(ptag) : 0;
+  kh_refresh(&priv);
 
-  tag_priv = ptag;
-  if ((master = km_findpriv(ptag)) == 0) exit(EXIT_FAILURE);
+  if ((kd = km_findpriv(tag_priv)) == 0) return (-1);
+  if (master) km_unref(master);
+  master = kd;
+
+  return (0);
 }
 
 /* --- @km_reload@ --- *
@@ -785,6 +627,26 @@ int km_reload(void)
   return (changep);
 }
 
+/* --- @km_clear@ --- *
+ *
+ * Arguments:	---
+ *
+ * Returns:	---
+ *
+ * Use:		Forget the currently loaded keyrings.  The @master@ key will
+ *		be cleared, but other keys already loaded will continue to
+ *		exist until their reference count drops to zero.  Call
+ *		@km_init@ to make everything work again.
+ */
+
+void km_clear(void)
+{
+  kh_clear(&priv);
+  kh_clear(&pub);
+  if (master) { km_unref(master); master = 0; }
+  if (tag_priv) { xfree(tag_priv); tag_priv = 0; }
+}
+
 /* --- @km_findpub@, @km_findpriv@ --- *
  *
  * Arguments:	@const char *tag@ = key tag to load
@@ -805,6 +667,41 @@ kdata *km_findpriv(const char *tag)
   else return (kh_find(&priv, tag ? tag : "tripe-dh", 1));
 }
 
+/* --- @km_findpubbyid@, @km_findprivbyid@ --- *
+ *
+ * Arguments:	@uint32 id@ = key id to load
+ *
+ * Returns:	Pointer to the kdata object if successful, or null on error.
+ *
+ * Use:		Fetches a public or private key from the keyring given its
+ *		numeric id.
+ */
+
+static kdata *findbyid(keyhalf *kh, uint32 id)
+{
+  key *k;
+  kdata *kd;
+
+  k = key_byid(kh->kf, id); if (!k) goto notfound;
+  kd = kh_find(kh, k->tag, 1); if (!kd) goto notfound;
+  if (kd->id != id) { km_unref(kd); goto notfound; }
+  return (kd);
+
+notfound:
+  a_warn("KX", "%s-keyring", kh->kind, "%s", kh->kr,
+	 "unknown-key-id", "0x%08lx", (unsigned long)id,
+	 A_END);
+  return (0);
+}
+
+kdata *km_findpubbyid(uint32 id) { return (findbyid(&pub, id)); }
+
+kdata *km_findprivbyid(uint32 id)
+{
+  if (id == master->id) { km_ref(master); return (master); }
+  else return findbyid(&priv, id);
+}
+
 /* --- @km_tag@ --- *
  *
  * Arguments:	@kdata *kd@ - pointer to the kdata object
@@ -837,10 +734,11 @@ void km_ref(kdata *kd) { kd->ref++; }
 void km_unref(kdata *kd)
 {
   if (--kd->ref) return;
-  if (kd->kpriv) mp_drop(kd->kpriv);
-  G_DESTROY(kd->g, kd->kpub);
+  if (kd->k) kd->grp->ops->freesc(kd->grp, kd->k);
+  kd->grp->ops->freege(kd->grp, kd->K);
+  kd->grp->ops->freegrp(kd->grp);
   xfree(kd->tag);
-  G_DESTROYGROUP(kd->g);
+  DESTROY(kd);
 }
 
 /*----- That's all, folks -------------------------------------------------*/