--- /dev/null
+/* -*-c-*-
+ *
+ * Key binary encoding
+ *
+ * (c) 1999 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 <stdlib.h>
+#include <string.h>
+
+#include <mLib/bits.h>
+#include <mLib/dstr.h>
+#include <mLib/sub.h>
+#include <mLib/sym.h>
+
+#include "key-data.h"
+#include "mp.h"
+#include "mptext.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @key_decode@ --- *
+ *
+ * Arguments: @const void *p@ = pointer to buffer to read
+ * @size_t sz@ = size of the buffer
+ *
+ * Returns: The newly-read key data, or null if it failed.
+ *
+ * Use: Decodes a binary representation of a key.
+ */
+
+key_data *key_decode(const void *p, size_t sz)
+{
+ const octet *q = p;
+ size_t psz;
+ key_data *kd;
+ unsigned e;
+
+ /* --- Parse the header information --- *
+ *
+ * Make sure the size matches external reality. Security holes have been
+ * known to creep in without this sort of check. (No, this isn't an after-
+ * the-fact patch-up.)
+ */
+
+ e = LOAD16(q);
+ psz = LOAD16(q + 2);
+ if (psz + 4 > sz)
+ return (0);
+
+ /* --- Now decide what to do --- */
+
+ switch (e & KF_ENCMASK) {
+
+ /* --- Plain binary data --- */
+
+ case KENC_BINARY:
+ case KENC_ENCRYPT:
+ kd = key_newbinary(e, q + 4, psz);
+ break;
+
+ /* --- Multiprecision integer data --- */
+
+ case KENC_MP:
+ kd = key_newmp(e, mp_loadb(e & KF_BURN ? MP_NEWSEC : MP_NEW,
+ q + 4, psz));
+ break;
+
+ /* --- String data --- */
+
+ case KENC_STRING:
+ kd = key_newraw(e);
+ kd->u.p = xmalloc(sz + 1);
+ memcpy(kd->u.p, q + 4, sz);
+ kd->u.p[sz] = 0;
+ break;
+
+ /* --- Elliptic curve point data --- */
+
+ case KENC_EC: {
+ size_t xsz, ysz;
+ kd = key_newraw(e);
+ EC_CREATE(&kd->u.e);
+ if (!sz) break;
+ if (sz < 2) return (0);
+ xsz = LOAD16(q + 4);
+ if (sz < xsz + 4) return (0);
+ ysz = LOAD16(q + 6 + xsz);
+ if (sz < xsz + ysz + 4) return (0);
+ kd->u.e.x = mp_loadb(MP_NEW, q + 6, xsz);
+ kd->u.e.y = mp_loadb(MP_NEW, q + 8 + xsz, ysz);
+ } break;
+
+ /* --- Structured key data --- */
+
+ case KENC_STRUCT: {
+ dstr d = DSTR_INIT;
+ key_data *nkd;
+
+ if ((e & ~KF_ENCMASK) || (psz & 3))
+ return (0);
+ q += 4;
+ kd = key_newstruct();
+
+ while (psz) {
+
+ /* --- Read the tag string --- */
+
+ DRESET(&d);
+ sz = LOAD8(q);
+ if (sz >= psz)
+ goto fail;
+ DPUTM(&d, q + 1, sz);
+ DPUTZ(&d);
+ sz = (sz + 4) & ~3;
+ q += sz; psz -= sz;
+
+ /* --- Read the encoding and size --- */
+
+ sz = (LOAD16(q + 2) + 7) & ~3;
+ if (sz > psz)
+ goto fail;
+
+ /* --- Create a table node and fill it in --- */
+
+ if ((nkd = key_decode(q, sz)) == 0)
+ goto fail;
+ key_structsteal(kd, d.buf, nkd);
+ psz -= sz;
+ q += sz;
+ }
+ dstr_destroy(&d);
+ break;
+
+ /* --- Tidy up after a failure --- */
+
+ fail:
+ dstr_destroy(&d);
+ key_drop(kd);
+ return (0);
+ } break;
+
+ /* --- Everything else --- */
+
+ default:
+ return (0);
+ }
+
+ /* --- OK, that was good --- */
+
+ kd->e = e;
+ return (kd);
+}
+
+/* --- @key_encode@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @dstr *d@ = pointer to destination string
+ * @const key_filter *kf@ = pointer to key selection block
+ *
+ * Returns: Nonzero if an item was actually written.
+ *
+ * Use: Encodes a key block as binary data.
+ */
+
+static int ksbyname(const void *a, const void *b) {
+ key_struct *const *x = a, *const *y = b;
+ return (strcmp(SYM_NAME(*x), SYM_NAME(*y)));
+}
+
+int key_encode(key_data *k, dstr *d, const key_filter *kf)
+{
+ int rc = 0;
+ if (!KEY_MATCH(k, kf))
+ return (0);
+ switch (k->e & KF_ENCMASK) {
+ case KENC_BINARY:
+ case KENC_ENCRYPT: {
+ char *p;
+
+ DENSURE(d, (k->u.k.sz + 7) & ~3);
+ p = d->buf + d->len;
+ STORE16(p, k->e);
+ STORE16(p + 2, k->u.k.sz);
+ d->len += 4;
+ DPUTM(d, k->u.k.k, k->u.k.sz);
+ rc = 1;
+ } break;
+
+ case KENC_MP: {
+ char *p;
+ size_t sz = mp_octets(k->u.m);
+
+ DENSURE(d, (sz + 7) & ~3);
+ p = d->buf + d->len;
+ STORE16(p, k->e);
+ STORE16(p + 2, sz);
+ mp_storeb(k->u.m, p + 4, sz);
+ d->len += sz + 4;
+ 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 = 0, ysz = 0;
+ 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;
+ key_struct *ks, **ksv;
+ size_t nks, j;
+ sym_iter i;
+
+ n = d->len;
+ DENSURE(d, 4);
+ p = d->buf + n;
+ STORE16(p, k->e & KF_ENCMASK);
+ d->len += 4;
+
+ for (nks = 0, sym_mkiter(&i, &k->u.s);
+ (ks = sym_next(&i)) != 0;
+ nks++);
+ if (nks) {
+ ksv = xmalloc(nks * sizeof(*ksv));
+ for (j = 0, sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; j++)
+ ksv[j] = ks;
+ qsort(ksv, nks, sizeof(*ksv), ksbyname);
+ for (j = 0; j < nks; j++) {
+ size_t o = d->len;
+ ks = ksv[j];
+ DENSURE(d, 1);
+ *(octet *)(d->buf + d->len++) = strlen(SYM_NAME(ks));
+ DPUTS(d, SYM_NAME(ks));
+ while (d->len & 3)
+ DPUTC(d, 0);
+ if (key_encode(ks->k, d, kf))
+ rc = 1;
+ else
+ d->len = o;
+ }
+ xfree(ksv);
+ }
+ if (!rc)
+ d->len = n;
+ else {
+ p = d->buf + n + 2;
+ n = d->len - n - 4;
+ STORE16(p, n);
+ }
+ } break;
+ }
+ while (d->len & 3)
+ DPUTC(d, 0);
+ return (rc);
+}
+
+/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff