| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: key-text.c,v 1.1 2000/02/12 18:21:02 mdw Exp $ |
| 4 | * |
| 5 | * Key textual encoding |
| 6 | * |
| 7 | * (c) 1999 Straylight/Edgeware |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of Catacomb. |
| 13 | * |
| 14 | * Catacomb is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU Library General Public License as |
| 16 | * published by the Free Software Foundation; either version 2 of the |
| 17 | * License, or (at your option) any later version. |
| 18 | * |
| 19 | * Catacomb is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU Library General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU Library General Public |
| 25 | * License along with Catacomb; if not, write to the Free |
| 26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 27 | * MA 02111-1307, USA. |
| 28 | */ |
| 29 | |
| 30 | /*----- Revision history --------------------------------------------------* |
| 31 | * |
| 32 | * $Log: key-text.c,v $ |
| 33 | * Revision 1.1 2000/02/12 18:21:02 mdw |
| 34 | * Overhaul of key management (again). |
| 35 | * |
| 36 | */ |
| 37 | |
| 38 | /*----- Header files ------------------------------------------------------*/ |
| 39 | |
| 40 | #include <stdlib.h> |
| 41 | #include <string.h> |
| 42 | |
| 43 | #include <mLib/base64.h> |
| 44 | #include <mLib/bits.h> |
| 45 | #include <mLib/dstr.h> |
| 46 | #include <mLib/sub.h> |
| 47 | #include <mLib/sym.h> |
| 48 | |
| 49 | #include "key-data.h" |
| 50 | #include "mp.h" |
| 51 | #include "mptext.h" |
| 52 | |
| 53 | /*----- Main code ---------------------------------------------------------*/ |
| 54 | |
| 55 | /* --- @key_read@ --- * |
| 56 | * |
| 57 | * Arguments: @const char *p@ = pointer to textual key representation |
| 58 | * @key_data *k@ = pointer to output block for key data |
| 59 | * @char **pp@ = where to store the end pointer |
| 60 | * |
| 61 | * Returns: Zero if all went well, nonzero if there was a problem. |
| 62 | * |
| 63 | * Use: Parses a textual key description. |
| 64 | */ |
| 65 | |
| 66 | int key_read(const char *p, key_data *k, char **pp) |
| 67 | { |
| 68 | unsigned e; |
| 69 | |
| 70 | /* --- Read the encoding type --- * |
| 71 | * |
| 72 | * The key format is `[FLAGS:]DATA'. If there is no encoding type |
| 73 | * named, assume that it's `binary' for backwards compatibility. |
| 74 | */ |
| 75 | |
| 76 | if (strchr(p, ':') == 0) |
| 77 | e = 0; |
| 78 | else { |
| 79 | char *q; |
| 80 | if (key_readflags(p, &q, &e, 0)) |
| 81 | return (-1); |
| 82 | p = q + 1; |
| 83 | } |
| 84 | |
| 85 | /* --- Now scan the data based on the encoding type --- */ |
| 86 | |
| 87 | k->e = e; |
| 88 | switch (e & KF_ENCMASK) { |
| 89 | |
| 90 | /* --- Binary encoding --- * |
| 91 | * |
| 92 | * Simply read out the Base64-encoded data. Since `,' and `]' are our |
| 93 | * delimeter characters, and they can't appear in Base64-encoded data, I |
| 94 | * can just do a simple search to find the end of the encoded data. |
| 95 | */ |
| 96 | |
| 97 | case KENC_BINARY: |
| 98 | case KENC_ENCRYPT: { |
| 99 | dstr d = DSTR_INIT; |
| 100 | base64_ctx b; |
| 101 | size_t sz = strcspn(p, ",]"); |
| 102 | |
| 103 | base64_init(&b); |
| 104 | base64_decode(&b, p, sz, &d); |
| 105 | base64_decode(&b, 0, 0, &d); |
| 106 | k->u.k.k = sub_alloc(d.len); |
| 107 | k->u.k.sz = d.len; |
| 108 | memcpy(k->u.k.k, d.buf, d.len); |
| 109 | dstr_destroy(&d); |
| 110 | p += sz; |
| 111 | } break; |
| 112 | |
| 113 | /* --- Multiprecision integer encoding --- * |
| 114 | * |
| 115 | * Multiprecision integers have a convenient reading function. |
| 116 | */ |
| 117 | |
| 118 | case KENC_MP: { |
| 119 | char *q; |
| 120 | mp *m = mp_readstring(MP_NEW, p, &q, 0); |
| 121 | if (!m) |
| 122 | return (-1); |
| 123 | if (k->e & KF_BURN) |
| 124 | mp_burn(m); |
| 125 | k->u.m = m; |
| 126 | p = q; |
| 127 | } break; |
| 128 | |
| 129 | /* --- Structured information encoding --- * |
| 130 | * |
| 131 | * The format for structured key data is `[NAME=KEY,...]', where the |
| 132 | * brackets are part of the syntax. Structured keys have no flags apart |
| 133 | * from the encoding. |
| 134 | * |
| 135 | * The binary encoding only allows names up to 255 bytes long. Check for |
| 136 | * this here. |
| 137 | */ |
| 138 | |
| 139 | case KENC_STRUCT: { |
| 140 | dstr d = DSTR_INIT; |
| 141 | char *q; |
| 142 | |
| 143 | /* --- Read the opening bracket --- */ |
| 144 | |
| 145 | k->e &= KF_ENCMASK; |
| 146 | if (*p != '[') |
| 147 | return (-1); |
| 148 | p++; |
| 149 | sym_create(&k->u.s); |
| 150 | |
| 151 | /* --- Read named key subparts --- */ |
| 152 | |
| 153 | for (;;) { |
| 154 | size_t sz; |
| 155 | key_struct *ks; |
| 156 | |
| 157 | /* --- Stop if there's a close-bracket --- * |
| 158 | * |
| 159 | * This allows `[]' to be an empty structured key, which is good. It |
| 160 | * also makes `[foo=enc:bar,]' legal, and that's less good but I can |
| 161 | * live with it. |
| 162 | */ |
| 163 | |
| 164 | if (*p == ']') |
| 165 | break; |
| 166 | |
| 167 | /* --- Read the name out and check the length --- */ |
| 168 | |
| 169 | if ((q = strchr(p, '=')) == 0) |
| 170 | goto fail; |
| 171 | sz = q - p; |
| 172 | if (sz >= 256) |
| 173 | goto fail; |
| 174 | DRESET(&d); |
| 175 | DPUTM(&d, p, sz); |
| 176 | DPUTZ(&d); |
| 177 | |
| 178 | /* --- Add an appropriate block to the key table --- * |
| 179 | * |
| 180 | * Simply destroy old data if there's already a match. |
| 181 | */ |
| 182 | |
| 183 | { |
| 184 | unsigned f; |
| 185 | ks = sym_find(&k->u.s, d.buf, d.len + 1, sizeof(*ks), &f); |
| 186 | if (f) |
| 187 | key_destroy(&ks->k); |
| 188 | } |
| 189 | |
| 190 | /* --- Read the key data for the subkey --- */ |
| 191 | |
| 192 | if (key_read(q + 1, &ks->k, &q)) { |
| 193 | sym_remove(&k->u.s, ks); |
| 194 | goto fail; |
| 195 | } |
| 196 | p = q; |
| 197 | |
| 198 | /* --- Read the comma or close-bracket --- */ |
| 199 | |
| 200 | if (*p == ']') |
| 201 | break; |
| 202 | else if (*p == ',') |
| 203 | p++; |
| 204 | else |
| 205 | goto fail; |
| 206 | } |
| 207 | |
| 208 | /* --- Step past the close bracket --- */ |
| 209 | |
| 210 | p++; |
| 211 | dstr_destroy(&d); |
| 212 | break; |
| 213 | |
| 214 | /* --- Tidy up after a failure --- */ |
| 215 | |
| 216 | fail: |
| 217 | dstr_destroy(&d); |
| 218 | key_destroy(k); |
| 219 | return (-1); |
| 220 | } break; |
| 221 | |
| 222 | /* --- Anything else is unknown --- */ |
| 223 | |
| 224 | default: |
| 225 | return (-1); |
| 226 | } |
| 227 | |
| 228 | /* --- Return the end pointer --- */ |
| 229 | |
| 230 | if (pp) |
| 231 | *pp = (char *)p; |
| 232 | return (0); |
| 233 | } |
| 234 | |
| 235 | /* --- @key_write@ --- * |
| 236 | * |
| 237 | * Arguments: @key_data *k@ = pointer to key data |
| 238 | * @dstr *d@ = destination string to write on |
| 239 | * @const key_filter *kf@ = pointer to key selection block |
| 240 | * |
| 241 | * Returns: Nonzero if an item was actually written. |
| 242 | * |
| 243 | * Use: Writes a key in a textual encoding. |
| 244 | */ |
| 245 | |
| 246 | int key_write(key_data *k, dstr *d, const key_filter *kf) |
| 247 | { |
| 248 | int rc = 0; |
| 249 | if (!KEY_MATCH(k, kf)) |
| 250 | return (0); |
| 251 | switch (k->e & KF_ENCMASK) { |
| 252 | case KENC_BINARY: |
| 253 | case KENC_ENCRYPT: { |
| 254 | base64_ctx b; |
| 255 | |
| 256 | if ((k->e & KF_ENCMASK) == KENC_BINARY) |
| 257 | key_writeflags(k->e, d); |
| 258 | else |
| 259 | DPUTS(d, "encrypt,secret"); |
| 260 | DPUTC(d, ':'); |
| 261 | base64_init(&b); |
| 262 | b.indent = ""; |
| 263 | b.maxline = 0; |
| 264 | base64_encode(&b, k->u.k.k, k->u.k.sz, d); |
| 265 | base64_encode(&b, 0, 0, d); |
| 266 | rc = 1; |
| 267 | } break; |
| 268 | case KENC_MP: |
| 269 | key_writeflags(k->e, d); |
| 270 | DPUTC(d, ':'); |
| 271 | mp_writedstr(k->u.m, d, 10); |
| 272 | rc = 1; |
| 273 | break; |
| 274 | case KENC_STRUCT: { |
| 275 | sym_iter i; |
| 276 | key_struct *ks; |
| 277 | char del = 0; |
| 278 | size_t n = d->len; |
| 279 | |
| 280 | DPUTS(d, "struct:["); |
| 281 | for (sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; ) { |
| 282 | size_t o = d->len; |
| 283 | if (del) |
| 284 | DPUTC(d, del); |
| 285 | DPUTS(d, SYM_NAME(ks)); |
| 286 | DPUTC(d, '='); |
| 287 | if (!key_write(&ks->k, d, kf)) |
| 288 | d->len = o; |
| 289 | else { |
| 290 | del = ','; |
| 291 | rc = 1; |
| 292 | } |
| 293 | } |
| 294 | if (!rc) |
| 295 | d->len = n; |
| 296 | else |
| 297 | DPUTC(d, ']'); |
| 298 | } break; |
| 299 | } |
| 300 | DPUTZ(d); |
| 301 | |
| 302 | return (rc); |
| 303 | } |
| 304 | |
| 305 | /*----- That's all, folks -------------------------------------------------*/ |