mdw@git.distorted.org.uk Git - catacomb/blob - key/key-data.c

   1 /* -*-c-*-
   2  *
   3  * Encoding and decoding of key data
   4  *
   5  * (c) 1999 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   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.
  16  *
  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.
  21  *
  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
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 #include <assert.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33
  34 #include <mLib/base64.h>
  35 #include <mLib/bits.h>
  36 #include <mLib/dstr.h>
  37 #include <mLib/sub.h>
  38 #include <mLib/sym.h>
  39
  40 #include "key-data.h"
  41 #include "mp.h"
  42 #include "mptext.h"
  43
  44 /*----- Reference counting stuff ------------------------------------------*/
  45
  46 /* --- @key_incref@ --- *
  47  *
  48  * Arguments:   @key_data *k@ = pointer to key data
  49  *
  50  * Returns:     ---
  51  *
  52  * Use:         Increments the refcount on a key data block.
  53  */
  54
  55 void key_incref(key_data *k) { KEY_INCREF(k); }
  56
  57 /* --- @key_destroy@ --- *
  58  *
  59  * Arguments:   @key_data *k@ = pointer to key data to destroy
  60  *
  61  * Returns:     ---
  62  *
  63  * Use:         Destroys a block of key data, regardless of reference count.
  64  *              Don't use this unless you know what you're doing.
  65  */
  66
  67 void key_destroy(key_data *k)
  68 {
  69   switch (k->e & KF_ENCMASK) {
  70     case KENC_BINARY:
  71     case KENC_ENCRYPT:
  72       if (k->u.k.k) {
  73         if (k->e & KF_BURN)
  74           memset(k->u.k.k, 0, k->u.k.sz);
  75         sub_free(k->u.k.k, k->u.k.sz);
  76       }
  77       break;
  78     case KENC_MP:
  79       mp_drop(k->u.m);
  80       break;
  81     case KENC_STRING:
  82       xfree(k->u.p);
  83       break;
  84     case KENC_EC:
  85       EC_DESTROY(&k->u.e);
  86       break;
  87     case KENC_STRUCT: {
  88       key_data *kd;
  89       key_subkeyiter i;
  90
  91       for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, 0, &kd); )
  92         KEY_DROP(kd);
  93       sym_destroy(&k->u.s);
  94     } break;
  95     default:
  96       abort();
  97   }
  98   DESTROY(k);
  99 }
 100
 101 /* --- @key_drop@ --- *
 102  *
 103  * Arguments:   @key_data *k@ = pointer to key data to destroy
 104  *
 105  * Returns:     ---
 106  *
 107  * Use:         Drops a reference to key data, destroying it if necessary.
 108  */
 109
 110 void key_drop(key_data *k) { KEY_DROP(k); }
 111
 112 /* --- @key_split@ --- *
 113  *
 114  * Arguments:   @key_data **kk@ = address of pointer to key data block
 115  *
 116  * Returns:     ---
 117  *
 118  * Use:         Replaces @*kk@ with a pointer to the same key data, but with
 119  *              just one reference.
 120  */
 121
 122 void key_split(key_data **kk)
 123 {
 124   key_data *k = *kk;
 125
 126   if (k->ref == 1)
 127     return;
 128   switch (k->e & KF_ENCMASK) {
 129     case KENC_BINARY:
 130       *kk = key_newbinary(k->e, k->u.k.k, k->u.k.sz);
 131       break;
 132     case KENC_ENCRYPT:
 133       *kk = key_newencrypted(k->e, k->u.k.k, k->u.k.sz);
 134       break;
 135     case KENC_MP:
 136       *kk = key_newmp(k->e, k->u.m);
 137       break;
 138     case KENC_STRING:
 139       *kk = key_newstring(k->e, k->u.p);
 140       break;
 141     case KENC_EC:
 142       *kk = key_newec(k->e, &k->u.e);
 143       break;
 144     case KENC_STRUCT: {
 145       key_subkeyiter i;
 146       const char *tag;
 147       key_data *kd;
 148
 149       *kk = key_newstruct();
 150       for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &kd); )
 151         key_structset(*kk, tag, kd);
 152     } break;
 153     default:
 154       abort();
 155   }
 156   key_drop(k);
 157 }
 158
 159 /*----- Setting new values ------------------------------------------------*/
 160
 161 /* --- @key_newraw@ --- *
 162  *
 163  * Arguments:   @unsigned e@ = encoding type to set
 164  *
 165  * Returns:     New key block, not filled in.
 166  */
 167
 168 key_data *key_newraw(unsigned e)
 169 {
 170   key_data *k = CREATE(key_data);
 171   k->e = e;
 172   k->ref = 1;
 173   return (k);
 174 }
 175
 176 /* --- @key_newbinary@ --- *
 177  *
 178  * Arguments:   @unsigned e@ = other encoding flags
 179  *              @const void *p@ = pointer to key data
 180  *              @size_t sz@ = size of the key data
 181  *
 182  * Returns:     New key data object.
 183  */
 184
 185 key_data *key_newbinary(unsigned e, const void *p, size_t sz)
 186 {
 187   key_data *k = key_newraw(KENC_BINARY | e);
 188   k->u.k.k = sub_alloc(sz);
 189   memcpy(k->u.k.k, p, sz);
 190   k->u.k.sz = sz;
 191   return (k);
 192 }
 193
 194 /* --- @key_newencrypted@ --- *
 195  *
 196  * Arguments:   @unsigned e@ = other encoding flags
 197  *              @const void *p@ = pointer to key data
 198  *              @size_t sz@ = size of the key data
 199  *
 200  * Returns:     New key data object.
 201  */
 202
 203 key_data *key_newencrypted(unsigned e, const void *p, size_t sz)
 204 {
 205   key_data *k = key_newraw(KENC_ENCRYPT | e);
 206   k->u.k.k = sub_alloc(sz);
 207   memcpy(k->u.k.k, p, sz);
 208   k->u.k.sz = sz;
 209   return (k);
 210 }
 211
 212 /* --- @key_newmp@ --- *
 213  *
 214  * Arguments:   @unsigned e@ = other encoding flags
 215  *              @mp *m@ = pointer to the value to set
 216  *
 217  * Returns:     New key data object.
 218  */
 219
 220 key_data *key_newmp(unsigned e, mp *m)
 221 {
 222   key_data *k = key_newraw(KENC_MP | e);
 223   k->u.m = MP_COPY(m);
 224   return (k);
 225 }
 226
 227 /* --- @key_newstring@ --- *
 228  *
 229  * Arguments:   @unsigned e@ = other encoding flags
 230  *              @const char *p@ = pointer to the value to set
 231  *
 232  * Returns:     New key data object.
 233  */
 234
 235 key_data *key_newstring(unsigned e, const char *p)
 236 {
 237   key_data *k = key_newraw(KENC_STRING | e);
 238   k->u.p = xstrdup(p);
 239   return (k);
 240 }
 241
 242 /* --- @key_newec@ --- *
 243  *
 244  * Arguments:   @unsigned e@ = other encoding flags
 245  *              @const ec *pt@ = pointer to the value to set
 246  *
 247  * Returns:     New key data object.
 248  */
 249
 250 key_data *key_newec(unsigned e, const ec *pt)
 251 {
 252   key_data *k = key_newraw(KENC_EC | e);
 253   EC_CREATE(&k->u.e);
 254   EC_COPY(&k->u.e, pt);
 255   return (k);
 256 }
 257
 258 /* --- @key_newstruct@ --- *
 259  *
 260  * Arguments:   ---
 261  *
 262  * Returns:     New key data object.
 263  */
 264
 265 key_data *key_newstruct(void)
 266 {
 267   key_data *k = key_newraw(KENC_STRUCT);
 268   sym_create(&k->u.s);
 269   return (k);
 270 }
 271
 272 /* --- @key_structfind@ --- *
 273  *
 274  * Arguments:   @key_data *k@ = pointer to key data block
 275  *              @const char *tag@ = pointer to tag string
 276  *
 277  * Returns:     Pointer to key data block, or null.
 278  *
 279  * Use:         Looks up the tag in a structured key.
 280  */
 281
 282 key_data *key_structfind(key_data *k, const char *tag)
 283 {
 284   key_struct *ks;
 285   assert(((void)"Key is not structured",
 286           (k->e & KF_ENCMASK) == KENC_STRUCT));
 287   ks = sym_find(&k->u.s, tag, -1, 0, 0);
 288   if (!ks)
 289     return (0);
 290   return (ks->k);
 291 }
 292
 293 /* --- @key_mksubkeyiter@ --- *
 294  *
 295  * Arguments:   @key_subkeyiter *i@ = pointer to iterator block
 296  *              @key_data *k@ = pointer to key data block
 297  *
 298  * Returns:     ---
 299  *
 300  * Use:         Initializes a subkey iterator.
 301  */
 302
 303 void key_mksubkeyiter(key_subkeyiter *i, key_data *k)
 304 {
 305   assert(((void)"Key is not structured",
 306           (k->e & KF_ENCMASK) == KENC_STRUCT));
 307   sym_mkiter(&i->i, &k->u.s);
 308 }
 309
 310 /* --- @key_nextsubkey@ --- *
 311  *
 312  * Arguments:   @key_structiter *i@ = pointer to iterator block
 313  *              @const char **tag@ = where to put the tag pointer, or null
 314  *              @key_data **kd@ = where to put the key data pointer, or null
 315  *
 316  * Returns:     Nonzero if there was another item, zero if we hit the
 317  *              end-stop.
 318  *
 319  * Use:         Collects the next subkey of a structured key.
 320  */
 321
 322 int key_nextsubkey(key_subkeyiter *i, const char **tag, key_data **kd)
 323 {
 324   key_struct *ks;
 325
 326   if ((ks = sym_next(&i->i)) == 0)
 327     return (0);
 328   if (tag) *tag = SYM_NAME(ks);
 329   if (kd) *kd = ks->k;
 330   return (1);
 331 }
 332
 333 /* --- @key_structset@, @key_structsteal@ --- *
 334  *
 335  * Arguments:   @key_data *k@ = pointer to key data block
 336  *              @const char *tag@ = pointer to tag string
 337  *              @key_data *kd@ = new key data to store
 338  *
 339  * Returns:     ---
 340  *
 341  * Use:         Creates a new subkey.  Stealing doesn't affect @kd@'s
 342  *              refcount.  If @kd@ is null, the subkey is deleted.
 343  */
 344
 345 static void structset(key_data *k, int stealp,
 346                       const char *tag, key_data *kd)
 347 {
 348   key_struct *ks;
 349   unsigned f;
 350
 351   assert(((void)"Key is not structured", k->e == KENC_STRUCT));
 352   assert(((void)"Key has multiple references", k->ref == 1));
 353   if (!kd) {
 354     ks = sym_find(&k->u.s, tag, -1, 0, 0);
 355     if (ks) sym_remove(&k->u.s, ks);
 356   } else {
 357     ks = sym_find(&k->u.s, tag, -1, sizeof(*ks), &f);
 358     if (f)
 359       key_drop(ks->k);
 360     if (!stealp) KEY_INCREF(kd);
 361     ks->k = kd;
 362   }
 363 }
 364
 365 void key_structset(key_data *k, const char *tag, key_data *kd)
 366   { structset(k, 0, tag, kd); }
 367 void key_structsteal(key_data *k, const char *tag, key_data *kd)
 368   { structset(k, 1, tag, kd); }
 369
 370 /*----- Miscellaneous operations ------------------------------------------*/
 371
 372 /* --- @key_do@ --- *
 373  *
 374  * Arguments:   @key_data *k@ = pointer to key data block
 375  *              @const key_filter *kf@ = pointer to filter block
 376  *              @dstr *d@ = pointer to base string
 377  *              @int (*func)(key_data *kd, dstr *d, void *p@ = function
 378  *              @void *p@ = argument to function
 379  *
 380  * Returns:     Nonzero return code from function, or zero.
 381  *
 382  * Use:         Runs a function over all the leaves of a key.
 383  */
 384
 385 int key_do(key_data *k, const key_filter *kf, dstr *d,
 386            int (*func)(key_data */*kd*/, dstr */*d*/, void */*p*/),
 387            void *p)
 388 {
 389   if (!KEY_MATCH(k, kf))
 390     return (0);
 391   if ((k->e & KF_ENCMASK) != KENC_STRUCT)
 392     return (func(k, d, p));
 393   else {
 394     key_subkeyiter i;
 395     const char *tag;
 396     size_t n = 0;
 397     int rc;
 398
 399     if (d)
 400       n = d->len;
 401     for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &k); ) {
 402       if (d) {
 403         d->len = n;
 404         dstr_putf(d, ".%s", tag);
 405       }
 406       if ((rc = key_do(k, kf, d, func, p)) != 0)
 407         return (rc);
 408     }
 409     return (0);
 410   }
 411 }
 412
 413 /* --- @key_copydata@ --- *
 414  *
 415  * Arguments:   @key_data *k@ = key data to copy
 416  *              @const key_filter *kf@ = pointer to filter block
 417  *
 418  * Returns:     Pointer to a copy of the data, or null if the root subkey
 419  *              didn't match the filter.
 420  *
 421  * Use:         Copies a chunk of key data.  Subkeys, whether they're
 422  *              structured or leaves, which don't match the filter aren't
 423  *              copied.  The copy may or may not have structure in common
 424  *              with the original.
 425  */
 426
 427 static int structmatchp(key_data *k, const key_filter *kf)
 428 {
 429   key_subkeyiter i;
 430
 431   if ((k->e & KF_ENCMASK) != KENC_STRUCT)
 432     return (KEY_MATCH(k, kf));
 433   else {
 434     for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, 0, &k); )
 435       if (!structmatchp(k, kf)) return (0);
 436     return (1);
 437   }
 438 }
 439
 440 key_data *key_copydata(key_data *k, const key_filter *kf)
 441 {
 442   key_subkeyiter i;
 443   const char *tag;
 444   key_data *kd, *kkd;
 445
 446   /* --- Trivial cases --- */
 447
 448   if (!KEY_MATCH(k, kf))
 449     return (0);
 450   else if (structmatchp(k, kf)) {
 451     key_incref(k);
 452     return (k);
 453   }
 454
 455   /* --- Copy a structured key recursively --- */
 456
 457   kkd = key_newstruct();
 458   for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &kd); ) {
 459     if ((kd = key_copydata(kd, kf)) != 0)
 460       key_structsteal(kkd, tag, kd);
 461   }
 462
 463   /* --- Done --- */
 464
 465   return (kkd);
 466 }
 467
 468 /*----- That's all, folks -------------------------------------------------*/