052b36d0 |
1 | /* -*-c-*- |
052b36d0 |
2 | * |
3 | * Key textual 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 | |
1589affa |
30 | #include <ctype.h> |
052b36d0 |
31 | #include <stdlib.h> |
32 | #include <string.h> |
33 | |
34 | #include <mLib/base64.h> |
35 | #include <mLib/bits.h> |
36 | #include <mLib/dstr.h> |
141c1284 |
37 | #include <mLib/macros.h> |
052b36d0 |
38 | #include <mLib/sub.h> |
39 | #include <mLib/sym.h> |
1ba83484 |
40 | #include <mLib/url.h> |
052b36d0 |
41 | |
42 | #include "key-data.h" |
43 | #include "mp.h" |
44 | #include "mptext.h" |
45 | |
46 | /*----- Main code ---------------------------------------------------------*/ |
47 | |
48 | /* --- @key_read@ --- * |
49 | * |
50 | * Arguments: @const char *p@ = pointer to textual key representation |
052b36d0 |
51 | * @char **pp@ = where to store the end pointer |
52 | * |
ef13e9a4 |
53 | * Returns: The newly-read key data, or null if it failed. |
052b36d0 |
54 | * |
55 | * Use: Parses a textual key description. |
56 | */ |
57 | |
ef13e9a4 |
58 | key_data *key_read(const char *p, char **pp) |
052b36d0 |
59 | { |
60 | unsigned e; |
ef13e9a4 |
61 | key_data *kd; |
052b36d0 |
62 | |
63 | /* --- Read the encoding type --- * |
64 | * |
65 | * The key format is `[FLAGS:]DATA'. If there is no encoding type |
66 | * named, assume that it's `binary' for backwards compatibility. |
67 | */ |
68 | |
69 | if (strchr(p, ':') == 0) |
70 | e = 0; |
71 | else { |
72 | char *q; |
73 | if (key_readflags(p, &q, &e, 0)) |
ef13e9a4 |
74 | return (0); |
052b36d0 |
75 | p = q + 1; |
76 | } |
77 | |
78 | /* --- Now scan the data based on the encoding type --- */ |
79 | |
052b36d0 |
80 | switch (e & KF_ENCMASK) { |
81 | |
82 | /* --- Binary encoding --- * |
83 | * |
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. |
87 | */ |
88 | |
89 | case KENC_BINARY: |
90 | case KENC_ENCRYPT: { |
91 | dstr d = DSTR_INIT; |
92 | base64_ctx b; |
93 | size_t sz = strcspn(p, ",]"); |
94 | |
95 | base64_init(&b); |
96 | base64_decode(&b, p, sz, &d); |
97 | base64_decode(&b, 0, 0, &d); |
ef13e9a4 |
98 | kd = key_newbinary(e, d.buf, d.len); |
052b36d0 |
99 | dstr_destroy(&d); |
100 | p += sz; |
101 | } break; |
102 | |
103 | /* --- Multiprecision integer encoding --- * |
104 | * |
105 | * Multiprecision integers have a convenient reading function. |
106 | */ |
107 | |
108 | case KENC_MP: { |
109 | char *q; |
ef13e9a4 |
110 | mp *m = mp_readstring(e & KF_BURN ? MP_NEWSEC : MP_NEW, p, &q, 0); |
052b36d0 |
111 | if (!m) |
ef13e9a4 |
112 | return (0); |
113 | kd = key_newmp(e, m); |
114 | MP_DROP(m); |
052b36d0 |
115 | p = q; |
116 | } break; |
117 | |
1ba83484 |
118 | /* --- String encoding --- * |
119 | * |
120 | * We use form-urlencoding to ensure that evil characters don't get out. |
121 | */ |
122 | |
123 | case KENC_STRING: { |
124 | dstr d = DSTR_INIT; |
125 | size_t sz = strcspn(p, ",]"); |
126 | const char *l = p + sz; |
127 | unsigned int ch; |
128 | int x, n; |
129 | |
130 | while (p < l) { |
131 | switch (*p) { |
132 | case '+': |
133 | DPUTC(&d, ' '); break; |
134 | case '%': |
135 | x = sscanf(p + 1, "%2x%n", &ch, &n); |
136 | if (x == 1) { DPUTC(&d, ch); p += n; break; } |
137 | default: |
138 | DPUTC(&d, *p); break; |
139 | } |
140 | p++; |
141 | } |
142 | DPUTZ(&d); |
ef13e9a4 |
143 | kd = key_newstring(e, d.buf); |
1ba83484 |
144 | dstr_destroy(&d); |
145 | } break; |
146 | |
147 | /* --- Elliptic curve encoding --- * |
148 | * |
149 | * Again, we have a convenient function. Assume for now that points |
150 | * aren't secret. (Reasonably safe.) |
151 | */ |
152 | |
153 | case KENC_EC: { |
ef13e9a4 |
154 | ec pt = EC_INIT; |
1ba83484 |
155 | qd_parse qd; |
156 | qd.p = p; |
157 | qd.e = 0; |
ef13e9a4 |
158 | if (!ec_ptparse(&qd, &pt)) |
159 | return (0); |
160 | kd = key_newec(e, &pt); |
161 | EC_DESTROY(&pt); |
1ba83484 |
162 | p = qd.p; |
163 | } break; |
164 | |
052b36d0 |
165 | /* --- Structured information encoding --- * |
166 | * |
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 |
169 | * from the encoding. |
170 | * |
171 | * The binary encoding only allows names up to 255 bytes long. Check for |
172 | * this here. |
173 | */ |
174 | |
175 | case KENC_STRUCT: { |
176 | dstr d = DSTR_INIT; |
ef13e9a4 |
177 | key_data *nkd; |
052b36d0 |
178 | char *q; |
179 | |
180 | /* --- Read the opening bracket --- */ |
181 | |
ef13e9a4 |
182 | kd = key_newstruct(); |
052b36d0 |
183 | if (*p != '[') |
ef13e9a4 |
184 | return (0); |
052b36d0 |
185 | p++; |
052b36d0 |
186 | |
187 | /* --- Read named key subparts --- */ |
188 | |
189 | for (;;) { |
190 | size_t sz; |
052b36d0 |
191 | |
192 | /* --- Stop if there's a close-bracket --- * |
193 | * |
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 |
196 | * live with it. |
197 | */ |
198 | |
199 | if (*p == ']') |
200 | break; |
201 | |
202 | /* --- Read the name out and check the length --- */ |
203 | |
204 | if ((q = strchr(p, '=')) == 0) |
205 | goto fail; |
206 | sz = q - p; |
207 | if (sz >= 256) |
208 | goto fail; |
209 | DRESET(&d); |
210 | DPUTM(&d, p, sz); |
211 | DPUTZ(&d); |
212 | |
052b36d0 |
213 | /* --- Read the key data for the subkey --- */ |
214 | |
ef13e9a4 |
215 | if ((nkd = key_read(q + 1, &q)) == 0) |
052b36d0 |
216 | goto fail; |
ef13e9a4 |
217 | key_structsteal(kd, d.buf, nkd); |
052b36d0 |
218 | p = q; |
219 | |
220 | /* --- Read the comma or close-bracket --- */ |
221 | |
222 | if (*p == ']') |
223 | break; |
224 | else if (*p == ',') |
225 | p++; |
226 | else |
227 | goto fail; |
228 | } |
229 | |
230 | /* --- Step past the close bracket --- */ |
231 | |
232 | p++; |
233 | dstr_destroy(&d); |
234 | break; |
235 | |
236 | /* --- Tidy up after a failure --- */ |
237 | |
238 | fail: |
239 | dstr_destroy(&d); |
ef13e9a4 |
240 | return (0); |
052b36d0 |
241 | } break; |
242 | |
243 | /* --- Anything else is unknown --- */ |
244 | |
245 | default: |
ef13e9a4 |
246 | return (0); |
052b36d0 |
247 | } |
248 | |
249 | /* --- Return the end pointer --- */ |
250 | |
ef13e9a4 |
251 | kd->e = e; |
052b36d0 |
252 | if (pp) |
253 | *pp = (char *)p; |
ef13e9a4 |
254 | return (kd); |
052b36d0 |
255 | } |
256 | |
257 | /* --- @key_write@ --- * |
258 | * |
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 |
262 | * |
263 | * Returns: Nonzero if an item was actually written. |
264 | * |
265 | * Use: Writes a key in a textual encoding. |
266 | */ |
45c0fd36 |
267 | |
052b36d0 |
268 | int key_write(key_data *k, dstr *d, const key_filter *kf) |
269 | { |
270 | int rc = 0; |
271 | if (!KEY_MATCH(k, kf)) |
272 | return (0); |
273 | switch (k->e & KF_ENCMASK) { |
274 | case KENC_BINARY: |
275 | case KENC_ENCRYPT: { |
276 | base64_ctx b; |
277 | |
278 | if ((k->e & KF_ENCMASK) == KENC_BINARY) |
279 | key_writeflags(k->e, d); |
280 | else |
281 | DPUTS(d, "encrypt,secret"); |
282 | DPUTC(d, ':'); |
283 | base64_init(&b); |
284 | b.indent = ""; |
285 | b.maxline = 0; |
286 | base64_encode(&b, k->u.k.k, k->u.k.sz, d); |
287 | base64_encode(&b, 0, 0, d); |
288 | rc = 1; |
289 | } break; |
290 | case KENC_MP: |
291 | key_writeflags(k->e, d); |
292 | DPUTC(d, ':'); |
293 | mp_writedstr(k->u.m, d, 10); |
294 | rc = 1; |
295 | break; |
1ba83484 |
296 | case KENC_STRING: { |
297 | const char *p = k->u.p; |
298 | key_writeflags(k->e, d); |
299 | DPUTC(d, ':'); |
300 | while (*p) { |
301 | if (*p == ' ') DPUTC(d, '+'); |
141c1284 |
302 | else if (!ISALNUM(*p)) dstr_putf(d, "%%%02x", *p); |
1ba83484 |
303 | else DPUTC(d, *p); |
304 | p++; |
305 | } |
306 | rc = 1; |
307 | } break; |
308 | case KENC_EC: |
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); |
312 | rc = 1; |
313 | break; |
052b36d0 |
314 | case KENC_STRUCT: { |
ef13e9a4 |
315 | key_subkeyiter i; |
316 | const char *tag; |
052b36d0 |
317 | char del = 0; |
318 | size_t n = d->len; |
319 | |
320 | DPUTS(d, "struct:["); |
ef13e9a4 |
321 | for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &k); ) { |
052b36d0 |
322 | size_t o = d->len; |
323 | if (del) |
324 | DPUTC(d, del); |
ef13e9a4 |
325 | DPUTS(d, tag); |
052b36d0 |
326 | DPUTC(d, '='); |
ef13e9a4 |
327 | if (!key_write(k, d, kf)) |
052b36d0 |
328 | d->len = o; |
329 | else { |
330 | del = ','; |
331 | rc = 1; |
332 | } |
333 | } |
334 | if (!rc) |
335 | d->len = n; |
336 | else |
337 | DPUTC(d, ']'); |
338 | } break; |
339 | } |
340 | DPUTZ(d); |
341 | |
342 | return (rc); |
343 | } |
344 | |
345 | /*----- That's all, folks -------------------------------------------------*/ |