git.distorted.org.uk Git - u/mdw/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 }
 157
 158 /*----- Setting new values ------------------------------------------------*/
 159
 160 /* --- @key_newraw@ --- *
 161  *
 162  * Arguments:   @unsigned e@ = encoding type to set
 163  *
 164  * Returns:     New key block, not filled in.
 165  */
 166
 167 key_data *key_newraw(unsigned e)
 168 {
 169   key_data *k = CREATE(key_data);
 170   k->e = e;
 171   k->ref = 1;
 172   return (k);
 173 }
 174
 175 /* --- @key_newbinary@ --- *
 176  *
 177  * Arguments:   @unsigned e@ = other encoding flags
 178  *              @const void *p@ = pointer to key data
 179  *              @size_t sz@ = size of the key data
 180  *
 181  * Returns:     New key data object.
 182  */
 183
 184 key_data *key_newbinary(unsigned e, const void *p, size_t sz)
 185 {
 186   key_data *k = key_newraw(KENC_BINARY | e);
 187   k->u.k.k = sub_alloc(sz);
 188   memcpy(k->u.k.k, p, sz);
 189   k->u.k.sz = sz;
 190   return (k);
 191 }
 192
 193 /* --- @key_newencrypted@ --- *
 194  *
 195  * Arguments:   @unsigned e@ = other encoding flags
 196  *              @const void *p@ = pointer to key data
 197  *              @size_t sz@ = size of the key data
 198  *
 199  * Returns:     New key data object.
 200  */
 201
 202 key_data *key_newencrypted(unsigned e, const void *p, size_t sz)
 203 {
 204   key_data *k = key_newraw(KENC_ENCRYPT | e);
 205   k->u.k.k = sub_alloc(sz);
 206   memcpy(k->u.k.k, p, sz);
 207   k->u.k.sz = sz;
 208   return (k);
 209 }
 210
 211 /* --- @key_newmp@ --- *
 212  *
 213  * Arguments:   @unsigned e@ = other encoding flags
 214  *              @mp *m@ = pointer to the value to set
 215  *
 216  * Returns:     New key data object.
 217  */
 218
 219 key_data *key_newmp(unsigned e, mp *m)
 220 {
 221   key_data *k = key_newraw(KENC_MP | e);
 222   k->u.m = MP_COPY(m);
 223   return (k);
 224 }
 225
 226 /* --- @key_newstring@ --- *
 227  *
 228  * Arguments:   @unsigned e@ = other encoding flags
 229  *              @const char *p@ = pointer to the value to set
 230  *
 231  * Returns:     New key data object.
 232  */
 233
 234 key_data *key_newstring(unsigned e, const char *p)
 235 {
 236   key_data *k = key_newraw(KENC_STRING | e);
 237   k->u.p = xstrdup(p);
 238   return (k);
 239 }
 240
 241 /* --- @key_newec@ --- *
 242  *
 243  * Arguments:   @unsigned e@ = other encoding flags
 244  *              @const ec *pt@ = pointer to the value to set
 245  *
 246  * Returns:     New key data object.
 247  */
 248
 249 key_data *key_newec(unsigned e, const ec *pt)
 250 {
 251   key_data *k = key_newraw(KENC_EC | e);
 252   EC_CREATE(&k->u.e);
 253   EC_COPY(&k->u.e, pt);
 254   return (k);
 255 }
 256
 257 /* --- @key_newstruct@ --- *
 258  *
 259  * Arguments:   ---
 260  *
 261  * Returns:     New key data object.
 262  */
 263
 264 key_data *key_newstruct(void)
 265 {
 266   key_data *k = key_newraw(KENC_STRUCT);
 267   sym_create(&k->u.s);
 268   return (k);
 269 }
 270
 271 /* --- @key_structfind@ --- *
 272  *
 273  * Arguments:   @key_data *k@ = pointer to key data block
 274  *              @const char *tag@ = pointer to tag string
 275  *
 276  * Returns:     Pointer to key data block, or null.
 277  *
 278  * Use:         Looks up the tag in a structured key.
 279  */
 280
 281 key_data *key_structfind(key_data *k, const char *tag)
 282 {
 283   key_struct *ks;
 284   assert(((void)"Key is not structured",
 285           (k->e & KF_ENCMASK) == KENC_STRUCT));
 286   ks = sym_find(&k->u.s, tag, -1, 0, 0);
 287   if (!ks)
 288     return (0);
 289   return (ks->k);
 290 }
 291
 292 /* --- @key_mksubkeyiter@ --- *
 293  *
 294  * Arguments:   @key_subkeyiter *i@ = pointer to iterator block
 295  *              @key_data *k@ = pointer to key data block
 296  *
 297  * Returns:     ---
 298  *
 299  * Use:         Initializes a subkey iterator.
 300  */
 301
 302 void key_mksubkeyiter(key_subkeyiter *i, key_data *k)
 303 {
 304   assert(((void)"Key is not structured",
 305           (k->e & KF_ENCMASK) == KENC_STRUCT));
 306   sym_mkiter(&i->i, &k->u.s);
 307 }
 308
 309 /* --- @key_nextsubkey@ --- *
 310  *
 311  * Arguments:   @key_structiter *i@ = pointer to iterator block
 312  *              @const char **tag@ = where to put the tag pointer, or null
 313  *              @key_data **kd@ = where to put the key data pointer, or null
 314  *
 315  * Returns:     Nonzero if there was another item, zero if we hit the
 316  *              end-stop.
 317  *
 318  * Use:         Collects the next subkey of a structured key.
 319  */
 320
 321 int key_nextsubkey(key_subkeyiter *i, const char **tag, key_data **kd)
 322 {
 323   key_struct *ks;
 324
 325   if ((ks = sym_next(&i->i)) == 0)
 326     return (0);
 327   if (tag) *tag = SYM_NAME(ks);
 328   if (kd) *kd = ks->k;
 329   return (1);
 330 }
 331
 332 /* --- @key_structset@, @key_structsteal@ --- *
 333  *
 334  * Arguments:   @key_data *k@ = pointer to key data block
 335  *              @const char *tag@ = pointer to tag string
 336  *              @key_data *kd@ = new key data to store
 337  *
 338  * Returns:     ---
 339  *
 340  * Use:         Creates a new subkey.  Stealing doesn't affect @kd@'s
 341  *              refcount.  If @kd@ is null, the subkey is deleted.
 342  */
 343
 344 static void structset(key_data *k, int stealp,
 345                       const char *tag, key_data *kd)
 346 {
 347   key_struct *ks;
 348   unsigned f;
 349
 350   assert(((void)"Key is not structured", k->e == KENC_STRUCT));
 351   assert(((void)"Key has multiple references", k->ref == 1));
 352   if (!kd) {
 353     ks = sym_find(&k->u.s, tag, -1, 0, 0);
 354     if (ks) sym_remove(&k->u.s, ks);
 355   } else {
 356     ks = sym_find(&k->u.s, tag, -1, sizeof(*ks), &f);
 357     if (f)
 358       key_drop(ks->k);
 359     if (!stealp) KEY_INCREF(kd);
 360     ks->k = kd;
 361   }
 362 }
 363
 364 void key_structset(key_data *k, const char *tag, key_data *kd)
 365   { structset(k, 0, tag, kd); }
 366 void key_structsteal(key_data *k, const char *tag, key_data *kd)
 367   { structset(k, 1, tag, kd); }
 368
 369 /*----- Miscellaneous operations ------------------------------------------*/
 370
 371 /* --- @key_do@ --- *
 372  *
 373  * Arguments:   @key_data *k@ = pointer to key data block
 374  *              @const key_filter *kf@ = pointer to filter block
 375  *              @dstr *d@ = pointer to base string
 376  *              @int (*func)(key_data *kd, dstr *d, void *p@ = function
 377  *              @void *p@ = argument to function
 378  *
 379  * Returns:     Nonzero return code from function, or zero.
 380  *
 381  * Use:         Runs a function over all the leaves of a key.
 382  */
 383
 384 int key_do(key_data *k, const key_filter *kf, dstr *d,
 385            int (*func)(key_data */*kd*/, dstr */*d*/, void */*p*/),
 386            void *p)
 387 {
 388   if (!KEY_MATCH(k, kf))
 389     return (0);
 390   if ((k->e & KF_ENCMASK) != KENC_STRUCT)
 391     return (func(k, d, p));
 392   else {
 393     key_subkeyiter i;
 394     const char *tag;
 395     size_t n = 0;
 396     int rc;
 397
 398     if (d)
 399       n = d->len;
 400     for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &k); ) {
 401       if (d) {
 402         d->len = n;
 403         dstr_putf(d, ".%s", tag);
 404       }
 405       if ((rc = key_do(k, kf, d, func, p)) != 0)
 406         return (rc);
 407     }
 408     return (0);
 409   }
 410 }
 411
 412 /* --- @key_copydata@ --- *
 413  *
 414  * Arguments:   @key_data *k@ = key data to copy
 415  *              @const key_filter *kf@ = pointer to filter block
 416  *
 417  * Returns:     Pointer to a copy of the data, or null if the root subkey
 418  *              didn't match the filter.
 419  *
 420  * Use:         Copies a chunk of key data.  Subkeys, whether they're
 421  *              structured or leaves, which don't match the filter aren't
 422  *              copied.  The copy may or may not have structure in common
 423  *              with the original.
 424  */
 425
 426 static int structmatchp(key_data *k, const key_filter *kf)
 427 {
 428   key_subkeyiter i;
 429
 430   if (!KEY_MATCH(k, kf)) return (0);
 431   else if ((k->e & KF_ENCMASK) == KENC_STRUCT) return (1);
 432   else {
 433     for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, 0, &k); )
 434       if (!structmatchp(k, kf)) return (0);
 435     return (1);
 436   }
 437 }
 438
 439 key_data *key_copydata(key_data *k, const key_filter *kf)
 440 {
 441   key_subkeyiter i;
 442   const char *tag;
 443   key_data *kd, *kkd;
 444
 445   /* --- Trivial cases --- */
 446
 447   if (!KEY_MATCH(k, kf))
 448     return (0);
 449   else if (structmatchp(k, kf)) {
 450     key_incref(k);
 451     return (k);
 452   }
 453
 454   /* --- Copy a structured key recursively --- */
 455
 456   kkd = key_newstruct();
 457   for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &kd); ) {
 458     if ((kd = key_copydata(kd, kf)) != 0)
 459       key_structsteal(kkd, tag, kd);
 460   }
 461
 462   /* --- Done --- */
 463
 464   return (kkd);
 465 }
 466
 467 /*----- That's all, folks -------------------------------------------------*/