--- /dev/null
+/* -*-c-*-
+ *
+ * Key textual 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 <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <mLib/base64.h>
+#include <mLib/bits.h>
+#include <mLib/dstr.h>
+#include <mLib/sub.h>
+#include <mLib/sym.h>
+#include <mLib/url.h>
+
+#include "key-data.h"
+#include "mp.h"
+#include "mptext.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @key_read@ --- *
+ *
+ * Arguments: @const char *p@ = pointer to textual key representation
+ * @char **pp@ = where to store the end pointer
+ *
+ * Returns: The newly-read key data, or null if it failed.
+ *
+ * Use: Parses a textual key description.
+ */
+
+key_data *key_read(const char *p, char **pp)
+{
+ unsigned e;
+ key_data *kd;
+
+ /* --- Read the encoding type --- *
+ *
+ * The key format is `[FLAGS:]DATA'. If there is no encoding type
+ * named, assume that it's `binary' for backwards compatibility.
+ */
+
+ if (strchr(p, ':') == 0)
+ e = 0;
+ else {
+ char *q;
+ if (key_readflags(p, &q, &e, 0))
+ return (0);
+ p = q + 1;
+ }
+
+ /* --- Now scan the data based on the encoding type --- */
+
+ switch (e & KF_ENCMASK) {
+
+ /* --- Binary encoding --- *
+ *
+ * Simply read out the Base64-encoded data. Since `,' and `]' are our
+ * delimeter characters, and they can't appear in Base64-encoded data, I
+ * can just do a simple search to find the end of the encoded data.
+ */
+
+ case KENC_BINARY:
+ case KENC_ENCRYPT: {
+ dstr d = DSTR_INIT;
+ base64_ctx b;
+ size_t sz = strcspn(p, ",]");
+
+ base64_init(&b);
+ base64_decode(&b, p, sz, &d);
+ base64_decode(&b, 0, 0, &d);
+ kd = key_newbinary(e, d.buf, d.len);
+ dstr_destroy(&d);
+ p += sz;
+ } break;
+
+ /* --- Multiprecision integer encoding --- *
+ *
+ * Multiprecision integers have a convenient reading function.
+ */
+
+ case KENC_MP: {
+ char *q;
+ mp *m = mp_readstring(e & KF_BURN ? MP_NEWSEC : MP_NEW, p, &q, 0);
+ if (!m)
+ return (0);
+ kd = key_newmp(e, m);
+ MP_DROP(m);
+ p = q;
+ } break;
+
+ /* --- String encoding --- *
+ *
+ * We use form-urlencoding to ensure that evil characters don't get out.
+ */
+
+ case KENC_STRING: {
+ dstr d = DSTR_INIT;
+ size_t sz = strcspn(p, ",]");
+ const char *l = p + sz;
+ unsigned int ch;
+ int x, n;
+
+ while (p < l) {
+ switch (*p) {
+ case '+':
+ DPUTC(&d, ' '); break;
+ case '%':
+ x = sscanf(p + 1, "%2x%n", &ch, &n);
+ if (x == 1) { DPUTC(&d, ch); p += n; break; }
+ default:
+ DPUTC(&d, *p); break;
+ }
+ p++;
+ }
+ DPUTZ(&d);
+ kd = key_newstring(e, d.buf);
+ dstr_destroy(&d);
+ } break;
+
+ /* --- Elliptic curve encoding --- *
+ *
+ * Again, we have a convenient function. Assume for now that points
+ * aren't secret. (Reasonably safe.)
+ */
+
+ case KENC_EC: {
+ ec pt = EC_INIT;
+ qd_parse qd;
+ qd.p = p;
+ qd.e = 0;
+ if (!ec_ptparse(&qd, &pt))
+ return (0);
+ kd = key_newec(e, &pt);
+ EC_DESTROY(&pt);
+ p = qd.p;
+ } break;
+
+ /* --- Structured information encoding --- *
+ *
+ * The format for structured key data is `[NAME=KEY,...]', where the
+ * brackets are part of the syntax. Structured keys have no flags apart
+ * from the encoding.
+ *
+ * The binary encoding only allows names up to 255 bytes long. Check for
+ * this here.
+ */
+
+ case KENC_STRUCT: {
+ dstr d = DSTR_INIT;
+ key_data *nkd;
+ char *q;
+
+ /* --- Read the opening bracket --- */
+
+ kd = key_newstruct();
+ if (*p != '[')
+ return (0);
+ p++;
+
+ /* --- Read named key subparts --- */
+
+ for (;;) {
+ size_t sz;
+
+ /* --- Stop if there's a close-bracket --- *
+ *
+ * This allows `[]' to be an empty structured key, which is good. It
+ * also makes `[foo=enc:bar,]' legal, and that's less good but I can
+ * live with it.
+ */
+
+ if (*p == ']')
+ break;
+
+ /* --- Read the name out and check the length --- */
+
+ if ((q = strchr(p, '=')) == 0)
+ goto fail;
+ sz = q - p;
+ if (sz >= 256)
+ goto fail;
+ DRESET(&d);
+ DPUTM(&d, p, sz);
+ DPUTZ(&d);
+
+ /* --- Read the key data for the subkey --- */
+
+ if ((nkd = key_read(q + 1, &q)) == 0)
+ goto fail;
+ key_structsteal(kd, d.buf, nkd);
+ p = q;
+
+ /* --- Read the comma or close-bracket --- */
+
+ if (*p == ']')
+ break;
+ else if (*p == ',')
+ p++;
+ else
+ goto fail;
+ }
+
+ /* --- Step past the close bracket --- */
+
+ p++;
+ dstr_destroy(&d);
+ break;
+
+ /* --- Tidy up after a failure --- */
+
+ fail:
+ dstr_destroy(&d);
+ return (0);
+ } break;
+
+ /* --- Anything else is unknown --- */
+
+ default:
+ return (0);
+ }
+
+ /* --- Return the end pointer --- */
+
+ kd->e = e;
+ if (pp)
+ *pp = (char *)p;
+ return (kd);
+}
+
+/* --- @key_write@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data
+ * @dstr *d@ = destination string to write on
+ * @const key_filter *kf@ = pointer to key selection block
+ *
+ * Returns: Nonzero if an item was actually written.
+ *
+ * Use: Writes a key in a textual encoding.
+ */
+
+int key_write(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: {
+ base64_ctx b;
+
+ if ((k->e & KF_ENCMASK) == KENC_BINARY)
+ key_writeflags(k->e, d);
+ else
+ DPUTS(d, "encrypt,secret");
+ DPUTC(d, ':');
+ base64_init(&b);
+ b.indent = "";
+ b.maxline = 0;
+ base64_encode(&b, k->u.k.k, k->u.k.sz, d);
+ base64_encode(&b, 0, 0, d);
+ rc = 1;
+ } break;
+ case KENC_MP:
+ key_writeflags(k->e, d);
+ DPUTC(d, ':');
+ mp_writedstr(k->u.m, d, 10);
+ rc = 1;
+ break;
+ case KENC_STRING: {
+ const char *p = k->u.p;
+ key_writeflags(k->e, d);
+ DPUTC(d, ':');
+ while (*p) {
+ if (*p == ' ') DPUTC(d, '+');
+ else if (!isalnum((unsigned char)*p)) dstr_putf(d, "%%%02x", *p);
+ else DPUTC(d, *p);
+ p++;
+ }
+ rc = 1;
+ } break;
+ case KENC_EC:
+ key_writeflags(k->e, d);
+ DPUTS(d, ":0x"); mp_writedstr(k->u.e.x, d, 16);
+ DPUTS(d, ",0x"); mp_writedstr(k->u.e.y, d, 16);
+ rc = 1;
+ break;
+ case KENC_STRUCT: {
+ key_subkeyiter i;
+ const char *tag;
+ char del = 0;
+ size_t n = d->len;
+
+ DPUTS(d, "struct:[");
+ for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &k); ) {
+ size_t o = d->len;
+ if (del)
+ DPUTC(d, del);
+ DPUTS(d, tag);
+ DPUTC(d, '=');
+ if (!key_write(k, d, kf))
+ d->len = o;
+ else {
+ del = ',';
+ rc = 1;
+ }
+ }
+ if (!rc)
+ d->len = n;
+ else
+ DPUTC(d, ']');
+ } break;
+ }
+ DPUTZ(d);
+
+ return (rc);
+}
+
+/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff