Add cyclic group abstraction, with test code. Separate off exponentation

[u/mdw/catacomb] / key-binary.c

diff --git a/key-binary.c b/key-binary.c
index 3e67d96..82a1ecb 100644 (file)
--- a/key-binary.c
+++ b/key-binary.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: key-binary.c,v 1.2 2000/06/17 11:25:20 mdw Exp $
+ * $Id: key-binary.c,v 1.5 2004/04/01 12:50:09 mdw Exp $
  *
  * Key binary encoding
  *
@@ -30,6 +30,20 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: key-binary.c,v $
+ * Revision 1.5  2004/04/01 12:50:09  mdw
+ * Add cyclic group abstraction, with test code.  Separate off exponentation
+ * functions for better static linking.  Fix a buttload of bugs on the way.
+ * Generally ensure that negative exponents do inversion correctly.  Add
+ * table of standard prime-field subgroups.  (Binary field subgroups are
+ * currently unimplemented but easy to add if anyone ever finds a good one.)
+ *
+ * Revision 1.4  2004/03/28 01:58:47  mdw
+ * Generate, store and retreive elliptic curve keys.
+ *
+ * Revision 1.3  2001/02/03 11:57:00  mdw
+ * Track mLib change: symbols no longer need to include a terminating
+ * null.
+ *
  * Revision 1.2  2000/06/17 11:25:20  mdw
  * Use secure memory interface from MP library.
  *
@@ -103,6 +117,29 @@ int key_decode(const void *p, size_t sz, key_data *k)
       k->u.m = mp_loadb(k->e & KF_BURN ? MP_NEWSEC : MP_NEW, q + 4, psz);
       break;
 
+    /* --- String data --- */
+
+    case KENC_STRING:
+      k->u.p = xmalloc(sz + 1);
+      memcpy(k->u.p, q + 4, sz);
+      k->u.p[sz] = 0;
+      break;
+
+    /* --- Elliptic curve point data --- */
+
+    case KENC_EC: {
+      size_t xsz, ysz;
+      EC_CREATE(&k->u.e);
+      if (!sz) break;
+      if (sz < 2) return (-1);
+      xsz = LOAD16(q + 4);
+      if (sz < xsz + 4) return (-1);
+      ysz = LOAD16(q + 6 + xsz);
+      if (sz < xsz + ysz + 4) return (-1);
+      k->u.e.x = mp_loadb(MP_NEW, q + 6, xsz);
+      k->u.e.y = mp_loadb(MP_NEW, q + 6 + xsz, ysz);
+    } break;
+
     /* --- Structured key data --- */
 
     case KENC_STRUCT: {
@@ -137,7 +174,7 @@ int key_decode(const void *p, size_t sz, key_data *k)
 
        /* --- Create a table node and fill it in --- */
 
-       ks = sym_find(&k->u.s, d.buf, d.len + 1, sizeof(*ks), &f);
+       ks = sym_find(&k->u.s, d.buf, d.len, sizeof(*ks), &f);
        if (f)
          goto fail;
        if (key_decode(q, sz, &ks->k)) {
@@ -212,6 +249,45 @@ int key_encode(key_data *k, dstr *d, const key_filter *kf)
       rc = 1;
     } break;
 
+    case KENC_STRING: {
+      char *p;
+      size_t sz = strlen(k->u.p);
+
+      DENSURE(d, (sz + 7) & ~3);
+      p = d->buf + d->len;
+      STORE16(p, k->e);
+      STORE16(p + 2, sz);
+      memcpy(p + 4, k->u.p, sz);
+      d->len += sz + 4;
+      rc = 1;
+    } break;
+
+    case KENC_EC: {
+      char *p;
+      size_t xsz, ysz;
+      size_t sz;
+
+      if (EC_ATINF(&k->u.e))
+       sz = 0;
+      else {
+       xsz = mp_octets(k->u.e.x);
+       ysz = mp_octets(k->u.e.y);
+       sz = xsz + ysz + 4;
+      }
+      DENSURE(d, (sz + 7) & ~3);
+      p = d->buf + d->len;
+      STORE16(p, k->e);
+      STORE16(p + 2, sz);
+      if (!EC_ATINF(&k->u.e)) {
+       STORE16(p + 4, xsz);
+       mp_storeb(k->u.e.x, p + 6, xsz);
+       STORE16(p + 6 + xsz, ysz);
+       mp_storeb(k->u.e.y, p + 8 + xsz, ysz);
+      }
+      d->len += sz + 4;
+      rc = 1;
+    } break;
+
     case KENC_STRUCT: {
       size_t n;
       char *p;