052b36d0 |
1 | /* -*-c-*- |
052b36d0 |
2 | * |
3 | * Key binary encoding |
4 | * |
5 | * (c) 1999 Straylight/Edgeware |
6 | */ |
7 | |
45c0fd36 |
8 | /*----- Licensing notice --------------------------------------------------* |
052b36d0 |
9 | * |
10 | * This file is part of Catacomb. |
11 | * |
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. |
45c0fd36 |
16 | * |
052b36d0 |
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. |
45c0fd36 |
21 | * |
052b36d0 |
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, |
25 | * MA 02111-1307, USA. |
26 | */ |
27 | |
052b36d0 |
28 | /*----- Header files ------------------------------------------------------*/ |
29 | |
30 | #include <stdlib.h> |
31 | #include <string.h> |
32 | |
33 | #include <mLib/bits.h> |
34 | #include <mLib/dstr.h> |
35 | #include <mLib/sub.h> |
36 | #include <mLib/sym.h> |
37 | |
38 | #include "key-data.h" |
39 | #include "mp.h" |
40 | #include "mptext.h" |
41 | |
42 | /*----- Main code ---------------------------------------------------------*/ |
43 | |
44 | /* --- @key_decode@ --- * |
45 | * |
46 | * Arguments: @const void *p@ = pointer to buffer to read |
47 | * @size_t sz@ = size of the buffer |
052b36d0 |
48 | * |
ef13e9a4 |
49 | * Returns: The newly-read key data, or null if it failed. |
052b36d0 |
50 | * |
51 | * Use: Decodes a binary representation of a key. |
52 | */ |
53 | |
ef13e9a4 |
54 | key_data *key_decode(const void *p, size_t sz) |
052b36d0 |
55 | { |
56 | const octet *q = p; |
57 | size_t psz; |
ef13e9a4 |
58 | key_data *kd; |
052b36d0 |
59 | unsigned e; |
60 | |
61 | /* --- Parse the header information --- * |
62 | * |
63 | * Make sure the size matches external reality. Security holes have been |
64 | * known to creep in without this sort of check. (No, this isn't an after- |
65 | * the-fact patch-up.) |
66 | */ |
67 | |
68 | e = LOAD16(q); |
69 | psz = LOAD16(q + 2); |
70 | if (psz + 4 > sz) |
ef13e9a4 |
71 | return (0); |
052b36d0 |
72 | |
73 | /* --- Now decide what to do --- */ |
74 | |
75 | switch (e & KF_ENCMASK) { |
76 | |
77 | /* --- Plain binary data --- */ |
78 | |
79 | case KENC_BINARY: |
80 | case KENC_ENCRYPT: |
ef13e9a4 |
81 | kd = key_newbinary(e, q + 4, psz); |
052b36d0 |
82 | break; |
83 | |
84 | /* --- Multiprecision integer data --- */ |
85 | |
86 | case KENC_MP: |
ef13e9a4 |
87 | kd = key_newmp(e, mp_loadb(e & KF_BURN ? MP_NEWSEC : MP_NEW, |
88 | q + 4, psz)); |
052b36d0 |
89 | break; |
90 | |
1ba83484 |
91 | /* --- String data --- */ |
92 | |
93 | case KENC_STRING: |
ef13e9a4 |
94 | kd = key_newraw(e); |
95 | kd->u.p = xmalloc(sz + 1); |
96 | memcpy(kd->u.p, q + 4, sz); |
97 | kd->u.p[sz] = 0; |
1ba83484 |
98 | break; |
99 | |
100 | /* --- Elliptic curve point data --- */ |
101 | |
102 | case KENC_EC: { |
103 | size_t xsz, ysz; |
ef13e9a4 |
104 | kd = key_newraw(e); |
105 | EC_CREATE(&kd->u.e); |
34e4f738 |
106 | if (!sz) break; |
ef13e9a4 |
107 | if (sz < 2) return (0); |
1ba83484 |
108 | xsz = LOAD16(q + 4); |
ef13e9a4 |
109 | if (sz < xsz + 4) return (0); |
1ba83484 |
110 | ysz = LOAD16(q + 6 + xsz); |
ef13e9a4 |
111 | if (sz < xsz + ysz + 4) return (0); |
112 | kd->u.e.x = mp_loadb(MP_NEW, q + 6, xsz); |
113 | kd->u.e.y = mp_loadb(MP_NEW, q + 8 + xsz, ysz); |
1ba83484 |
114 | } break; |
115 | |
052b36d0 |
116 | /* --- Structured key data --- */ |
117 | |
118 | case KENC_STRUCT: { |
119 | dstr d = DSTR_INIT; |
ef13e9a4 |
120 | key_data *nkd; |
052b36d0 |
121 | |
ef13e9a4 |
122 | if ((e & ~KF_ENCMASK) || (psz & 3)) |
123 | return (0); |
052b36d0 |
124 | q += 4; |
ef13e9a4 |
125 | kd = key_newstruct(); |
052b36d0 |
126 | |
127 | while (psz) { |
128 | |
129 | /* --- Read the tag string --- */ |
130 | |
131 | DRESET(&d); |
132 | sz = LOAD8(q); |
133 | if (sz >= psz) |
134 | goto fail; |
135 | DPUTM(&d, q + 1, sz); |
136 | DPUTZ(&d); |
137 | sz = (sz + 4) & ~3; |
138 | q += sz; psz -= sz; |
139 | |
140 | /* --- Read the encoding and size --- */ |
141 | |
052b36d0 |
142 | sz = (LOAD16(q + 2) + 7) & ~3; |
143 | if (sz > psz) |
144 | goto fail; |
145 | |
146 | /* --- Create a table node and fill it in --- */ |
147 | |
ef13e9a4 |
148 | if ((nkd = key_decode(q, sz)) == 0) |
052b36d0 |
149 | goto fail; |
ef13e9a4 |
150 | key_structsteal(kd, d.buf, nkd); |
052b36d0 |
151 | psz -= sz; |
152 | q += sz; |
153 | } |
154 | dstr_destroy(&d); |
155 | break; |
156 | |
157 | /* --- Tidy up after a failure --- */ |
158 | |
159 | fail: |
160 | dstr_destroy(&d); |
ef13e9a4 |
161 | key_drop(kd); |
162 | return (0); |
052b36d0 |
163 | } break; |
164 | |
165 | /* --- Everything else --- */ |
166 | |
167 | default: |
ef13e9a4 |
168 | return (0); |
052b36d0 |
169 | } |
170 | |
171 | /* --- OK, that was good --- */ |
172 | |
ef13e9a4 |
173 | kd->e = e; |
174 | return (kd); |
052b36d0 |
175 | } |
176 | |
177 | /* --- @key_encode@ --- * |
178 | * |
179 | * Arguments: @key_data *k@ = pointer to key data block |
180 | * @dstr *d@ = pointer to destination string |
181 | * @const key_filter *kf@ = pointer to key selection block |
182 | * |
183 | * Returns: Nonzero if an item was actually written. |
184 | * |
185 | * Use: Encodes a key block as binary data. |
186 | */ |
187 | |
898a4e25 |
188 | static int ksbyname(const void *a, const void *b) { |
189 | key_struct *const *x = a, *const *y = b; |
190 | return (strcmp(SYM_NAME(*x), SYM_NAME(*y))); |
191 | } |
192 | |
052b36d0 |
193 | int key_encode(key_data *k, dstr *d, const key_filter *kf) |
194 | { |
195 | int rc = 0; |
196 | if (!KEY_MATCH(k, kf)) |
197 | return (0); |
198 | switch (k->e & KF_ENCMASK) { |
199 | case KENC_BINARY: |
200 | case KENC_ENCRYPT: { |
201 | char *p; |
202 | |
203 | DENSURE(d, (k->u.k.sz + 7) & ~3); |
204 | p = d->buf + d->len; |
205 | STORE16(p, k->e); |
206 | STORE16(p + 2, k->u.k.sz); |
207 | d->len += 4; |
208 | DPUTM(d, k->u.k.k, k->u.k.sz); |
209 | rc = 1; |
210 | } break; |
211 | |
212 | case KENC_MP: { |
213 | char *p; |
214 | size_t sz = mp_octets(k->u.m); |
215 | |
216 | DENSURE(d, (sz + 7) & ~3); |
217 | p = d->buf + d->len; |
218 | STORE16(p, k->e); |
219 | STORE16(p + 2, sz); |
220 | mp_storeb(k->u.m, p + 4, sz); |
221 | d->len += sz + 4; |
222 | rc = 1; |
223 | } break; |
224 | |
1ba83484 |
225 | case KENC_STRING: { |
226 | char *p; |
227 | size_t sz = strlen(k->u.p); |
228 | |
229 | DENSURE(d, (sz + 7) & ~3); |
230 | p = d->buf + d->len; |
231 | STORE16(p, k->e); |
232 | STORE16(p + 2, sz); |
233 | memcpy(p + 4, k->u.p, sz); |
234 | d->len += sz + 4; |
235 | rc = 1; |
236 | } break; |
237 | |
238 | case KENC_EC: { |
239 | char *p; |
898a4e25 |
240 | size_t xsz = 0, ysz = 0; |
34e4f738 |
241 | size_t sz; |
1ba83484 |
242 | |
34e4f738 |
243 | if (EC_ATINF(&k->u.e)) |
244 | sz = 0; |
245 | else { |
246 | xsz = mp_octets(k->u.e.x); |
247 | ysz = mp_octets(k->u.e.y); |
248 | sz = xsz + ysz + 4; |
249 | } |
1ba83484 |
250 | DENSURE(d, (sz + 7) & ~3); |
251 | p = d->buf + d->len; |
252 | STORE16(p, k->e); |
253 | STORE16(p + 2, sz); |
34e4f738 |
254 | if (!EC_ATINF(&k->u.e)) { |
255 | STORE16(p + 4, xsz); |
256 | mp_storeb(k->u.e.x, p + 6, xsz); |
257 | STORE16(p + 6 + xsz, ysz); |
258 | mp_storeb(k->u.e.y, p + 8 + xsz, ysz); |
259 | } |
1ba83484 |
260 | d->len += sz + 4; |
261 | rc = 1; |
262 | } break; |
263 | |
052b36d0 |
264 | case KENC_STRUCT: { |
265 | size_t n; |
266 | char *p; |
898a4e25 |
267 | key_struct *ks, **ksv; |
268 | size_t nks, j; |
052b36d0 |
269 | sym_iter i; |
270 | |
271 | n = d->len; |
272 | DENSURE(d, 4); |
273 | p = d->buf + n; |
274 | STORE16(p, k->e & KF_ENCMASK); |
275 | d->len += 4; |
45c0fd36 |
276 | |
898a4e25 |
277 | for (nks = 0, sym_mkiter(&i, &k->u.s); |
278 | (ks = sym_next(&i)) != 0; |
279 | nks++); |
280 | if (nks) { |
281 | ksv = xmalloc(nks * sizeof(*ksv)); |
282 | for (j = 0, sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; j++) |
283 | ksv[j] = ks; |
284 | qsort(ksv, nks, sizeof(*ksv), ksbyname); |
285 | for (j = 0; j < nks; j++) { |
286 | size_t o = d->len; |
287 | ks = ksv[j]; |
288 | DENSURE(d, 1); |
289 | *(octet *)(d->buf + d->len++) = strlen(SYM_NAME(ks)); |
290 | DPUTS(d, SYM_NAME(ks)); |
291 | while (d->len & 3) |
292 | DPUTC(d, 0); |
ef13e9a4 |
293 | if (key_encode(ks->k, d, kf)) |
898a4e25 |
294 | rc = 1; |
295 | else |
296 | d->len = o; |
297 | } |
298 | xfree(ksv); |
052b36d0 |
299 | } |
300 | if (!rc) |
45c0fd36 |
301 | d->len = n; |
052b36d0 |
302 | else { |
303 | p = d->buf + n + 2; |
304 | n = d->len - n - 4; |
305 | STORE16(p, n); |
306 | } |
307 | } break; |
308 | } |
309 | while (d->len & 3) |
310 | DPUTC(d, 0); |
311 | return (rc); |
312 | } |
313 | |
314 | /*----- That's all, folks -------------------------------------------------*/ |