5 * (c) 1999 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Catacomb.
12 * Catacomb is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Library General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
17 * Catacomb is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU Library General Public License for more details.
22 * You should have received a copy of the GNU Library General Public
23 * License along with Catacomb; if not, write to the Free
24 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
28 /*----- Header files ------------------------------------------------------*/
34 #include <mLib/base64.h>
35 #include <mLib/bits.h>
36 #include <mLib/dstr.h>
37 #include <mLib/macros.h>
46 /*----- Main code ---------------------------------------------------------*/
48 /* --- @key_read@ --- *
50 * Arguments: @const char *p@ = pointer to textual key representation
51 * @char **pp@ = where to store the end pointer
53 * Returns: The newly-read key data, or null if it failed.
55 * Use: Parses a textual key description.
58 key_data *key_read(const char *p, char **pp)
63 /* --- Read the encoding type --- *
65 * The key format is `[FLAGS:]DATA'. If there is no encoding type
66 * named, assume that it's `binary' for backwards compatibility.
69 if (strchr(p, ':') == 0)
73 if (key_readflags(p, &q, &e, 0))
78 /* --- Now scan the data based on the encoding type --- */
80 switch (e & KF_ENCMASK) {
82 /* --- Binary encoding --- *
84 * Simply read out the Base64-encoded data. Since `,' and `]' are our
85 * delimeter characters, and they can't appear in Base64-encoded data, I
86 * can just do a simple search to find the end of the encoded data.
93 size_t sz = strcspn(p, ",]");
96 base64_decode(&b, p, sz, &d);
97 base64_decode(&b, 0, 0, &d);
98 kd = key_newbinary(e, d.buf, d.len);
103 /* --- Multiprecision integer encoding --- *
105 * Multiprecision integers have a convenient reading function.
110 mp *m = mp_readstring(e & KF_BURN ? MP_NEWSEC : MP_NEW, p, &q, 0);
113 kd = key_newmp(e, m);
118 /* --- String encoding --- *
120 * We use form-urlencoding to ensure that evil characters don't get out.
125 size_t sz = strcspn(p, ",]");
126 const char *l = p + sz;
133 DPUTC(&d, ' '); break;
135 x = sscanf(p + 1, "%2x%n", &ch, &n);
136 if (x == 1) { DPUTC(&d, ch); p += n; break; }
138 DPUTC(&d, *p); break;
143 kd = key_newstring(e, d.buf);
147 /* --- Elliptic curve encoding --- *
149 * Again, we have a convenient function. Assume for now that points
150 * aren't secret. (Reasonably safe.)
158 if (!ec_ptparse(&qd, &pt))
160 kd = key_newec(e, &pt);
165 /* --- Structured information encoding --- *
167 * The format for structured key data is `[NAME=KEY,...]', where the
168 * brackets are part of the syntax. Structured keys have no flags apart
171 * The binary encoding only allows names up to 255 bytes long. Check for
180 /* --- Read the opening bracket --- */
182 kd = key_newstruct();
187 /* --- Read named key subparts --- */
192 /* --- Stop if there's a close-bracket --- *
194 * This allows `[]' to be an empty structured key, which is good. It
195 * also makes `[foo=enc:bar,]' legal, and that's less good but I can
202 /* --- Read the name out and check the length --- */
204 if ((q = strchr(p, '=')) == 0)
213 /* --- Read the key data for the subkey --- */
215 if ((nkd = key_read(q + 1, &q)) == 0)
217 key_structsteal(kd, d.buf, nkd);
220 /* --- Read the comma or close-bracket --- */
230 /* --- Step past the close bracket --- */
236 /* --- Tidy up after a failure --- */
243 /* --- Anything else is unknown --- */
249 /* --- Return the end pointer --- */
257 /* --- @key_write@ --- *
259 * Arguments: @key_data *k@ = pointer to key data
260 * @dstr *d@ = destination string to write on
261 * @const key_filter *kf@ = pointer to key selection block
263 * Returns: Nonzero if an item was actually written.
265 * Use: Writes a key in a textual encoding.
268 int key_write(key_data *k, dstr *d, const key_filter *kf)
271 if (!KEY_MATCH(k, kf))
273 switch (k->e & KF_ENCMASK) {
278 if ((k->e & KF_ENCMASK) == KENC_BINARY)
279 key_writeflags(k->e, d);
281 DPUTS(d, "encrypt,secret");
286 base64_encode(&b, k->u.k.k, k->u.k.sz, d);
287 base64_encode(&b, 0, 0, d);
291 key_writeflags(k->e, d);
293 mp_writedstr(k->u.m, d, 10);
297 const char *p = k->u.p;
298 key_writeflags(k->e, d);
301 if (*p == ' ') DPUTC(d, '+');
302 else if (!ISALNUM(*p)) dstr_putf(d, "%%%02x", *p);
309 key_writeflags(k->e, d);
310 DPUTS(d, ":0x"); mp_writedstr(k->u.e.x, d, 16);
311 DPUTS(d, ",0x"); mp_writedstr(k->u.e.y, d, 16);
320 DPUTS(d, "struct:[");
321 for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &k); ) {
327 if (!key_write(k, d, kf))
345 /*----- That's all, folks -------------------------------------------------*/