X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/fc2d44af772db6c046820007555609c8352e101e..c90ce6bb395bac18afa5b189e4664151d4d8ea2c:/progs/cc-kem.c?ds=sidebyside

diff --git a/progs/cc-kem.c b/progs/cc-kem.c
index 71c89e47..1e99e05d 100644
--- a/progs/cc-kem.c
+++ b/progs/cc-kem.c
@@ -44,6 +44,7 @@
 #include "dh.h"
 #include "rsa.h"
 #include "x25519.h"
+#include "x448.h"
 
 #include "rmd160.h"
 #include "blowfish-cbc.h"
@@ -603,70 +604,79 @@ static const kemops ec_decops = {
   ec_decinit, dh_decdoit, dh_enccheck, dh_encdestroy
 };
 
-/* --- X25519 --- */
-
-static kem *x25519_encinit(key *k, void *kd) { return (CREATE(kem)); }
-static void x25519_encdestroy(kem *k) { DESTROY(k); }
-
-static const char *x25519_enccheck(kem *k)
-{
-  x25519_pub *kd = k->kd;
-
-  if (kd->pub.sz != X25519_PUBSZ)
-    return ("incorrect X25519 public key length");
-  return (0);
-}
-
-static int x25519_encdoit(kem *k, dstr *d, ghash *h)
-{
-  octet t[X25519_KEYSZ], z[X25519_OUTSZ];
-  x25519_pub *kd = k->kd;
-
-  rand_get(RAND_GLOBAL, t, sizeof(t));
-  dstr_ensure(d, X25519_PUBSZ);
-  x25519((octet *)d->buf, t, x25519_base);
-  x25519(z, t, kd->pub.k);
-  d->len += X25519_PUBSZ;
-  GH_HASH(h, d->buf, X25519_PUBSZ);
-  GH_HASH(h, z, X25519_OUTSZ);
-  return (0);
-}
-
-static const char *x25519_deccheck(kem *k)
-{
-  x25519_priv *kd = k->kd;
-
-  if (kd->priv.sz != X25519_KEYSZ)
-    return ("incorrect X25519 private key length");
-  if (kd->pub.sz != X25519_PUBSZ)
-    return ("incorrect X25519 public key length");
-  return (0);
-}
-
-static int x25519_decdoit(kem *k, dstr *d, ghash *h)
-{
-  octet z[X25519_OUTSZ];
-  x25519_priv *kd = k->kd;
-  int rc = -1;
-
-  if (d->len != X25519_PUBSZ) goto done;
-  x25519(z, kd->priv.k, (const octet *)d->buf);
-  GH_HASH(h, d->buf, X25519_PUBSZ);
-  GH_HASH(h, z, X25519_OUTSZ);
-  rc = 0;
-done:
-  return (rc);
-}
-
-static const kemops x25519_encops = {
-  x25519_pubfetch, sizeof(x25519_pub),
-  x25519_encinit, x25519_encdoit, x25519_enccheck, x25519_encdestroy
-};
-
-static const kemops x25519_decops = {
-  x25519_privfetch, sizeof(x25519_priv),
-  x25519_encinit, x25519_decdoit, x25519_deccheck, x25519_encdestroy
-};
+/* --- X25519 and similar schemes --- */
+
+#define XDHS(_)								\
+  _(x25519, X25519)							\
+  _(x448, X448)
+
+#define XDHDEF(xdh, XDH)						\
+									\
+  static kem *xdh##_encinit(key *k, void *kd) { return (CREATE(kem)); }	\
+  static void xdh##_encdestroy(kem *k) { DESTROY(k); }			\
+									\
+  static const char *xdh##_enccheck(kem *k)				\
+  {									\
+    xdh##_pub *kd = k->kd;						\
+									\
+    if (kd->pub.sz != XDH##_PUBSZ)					\
+      return ("incorrect " #XDH "public key length");			\
+    return (0);								\
+  }									\
+									\
+  static int xdh##_encdoit(kem *k, dstr *d, ghash *h)			\
+  {									\
+    octet t[XDH##_KEYSZ], z[XDH##_OUTSZ];				\
+    xdh##_pub *kd = k->kd;						\
+									\
+    rand_get(RAND_GLOBAL, t, sizeof(t));				\
+    dstr_ensure(d, XDH##_PUBSZ);					\
+    xdh((octet *)d->buf, t, xdh##_base);				\
+    xdh(z, t, kd->pub.k);						\
+    d->len += XDH##_PUBSZ;						\
+    GH_HASH(h, d->buf, XDH##_PUBSZ);					\
+    GH_HASH(h, z, XDH##_OUTSZ);						\
+    return (0);								\
+  }									\
+									\
+  static const char *xdh##_deccheck(kem *k)				\
+  {									\
+    xdh##_priv *kd = k->kd;						\
+									\
+    if (kd->priv.sz != XDH##_KEYSZ)					\
+      return ("incorrect " #XDH " private key length");			\
+    if (kd->pub.sz != XDH##_PUBSZ)					\
+      return ("incorrect " #XDH " public key length");			\
+    return (0);								\
+  }									\
+									\
+  static int xdh##_decdoit(kem *k, dstr *d, ghash *h)			\
+  {									\
+    octet z[XDH##_OUTSZ];						\
+    xdh##_priv *kd = k->kd;						\
+    int rc = -1;							\
+									\
+    if (d->len != XDH##_PUBSZ) goto done;				\
+    xdh(z, kd->priv.k, (const octet *)d->buf);				\
+    GH_HASH(h, d->buf, XDH##_PUBSZ);					\
+    GH_HASH(h, z, XDH##_OUTSZ);						\
+    rc = 0;								\
+  done:									\
+    return (rc);							\
+  }									\
+									\
+  static const kemops xdh##_encops = {					\
+    xdh##_pubfetch, sizeof(xdh##_pub),					\
+    xdh##_encinit, xdh##_encdoit, xdh##_enccheck, xdh##_encdestroy	\
+  };									\
+									\
+  static const kemops xdh##_decops = {					\
+    xdh##_privfetch, sizeof(xdh##_priv),				\
+    xdh##_encinit, xdh##_decdoit, xdh##_deccheck, xdh##_encdestroy	\
+  };
+
+XDHS(XDHDEF)
+#undef XDHDEF
 
 /* --- Symmetric --- */
 
@@ -736,7 +746,10 @@ const struct kemtab kemtab[] = {
   { "dh",	&dh_encops,	&dh_decops },
   { "bindh",	&bindh_encops,	&bindh_decops },
   { "ec",	&ec_encops,	&ec_decops },
-  { "x25519",	&x25519_encops,	&x25519_decops },
+#define XDHTAB(xdh, XDH)						\
+  { #xdh,	&xdh##_encops,	&xdh##_decops },
+  XDHS(XDHTAB)
+#undef XDHTAB
   { "symm",	&symm_encops,	&symm_decops },
   { 0,		0,		0 }
 };
@@ -847,16 +860,6 @@ k_found:;
 	halg, t.buf);
   }
 
-  dstr_reset(&d);
-  if ((q = key_getattr(0, k, "kdf")) == 0) {
-    dstr_putf(&d, "%s-mgf", kk->hc->name);
-    q = d.buf;
-  }
-  if ((kk->cxc = gcipher_byname(q)) == 0) {
-    die(EXIT_FAILURE, "encryption scheme (KDF) `%s' not found in key `%s'",
-	q, t.buf);
-  }
-
   if (!balg)
     bt = bulktab;
   else {
@@ -874,6 +877,16 @@ k_found:;
   *bc = bo->init(k, balg, kk->hc->name);
   (*bc)->ops = bo;
 
+  dstr_reset(&d);
+  if ((q = key_getattr(0, k, "kdf")) == 0) {
+    dstr_putf(&d, "%s-mgf", kk->hc->name);
+    q = d.buf;
+  }
+  if ((kk->cxc = gcipher_byname(q)) == 0) {
+    die(EXIT_FAILURE, "encryption scheme (KDF) `%s' not found in key `%s'",
+	q, t.buf);
+  }
+
   /* --- Tidy up --- */
 
   dstr_destroy(&d);