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

   1 /* -*-c-*-
   2  *
   3  * $Id$
   4  *
   5  * Encoding and decoding of key data
   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 /*----- Header files ------------------------------------------------------*/
  31
  32 #include <assert.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35
  36 #include <mLib/base64.h>
  37 #include <mLib/bits.h>
  38 #include <mLib/dstr.h>
  39 #include <mLib/sub.h>
  40 #include <mLib/sym.h>
  41
  42 #include "key-data.h"
  43 #include "mp.h"
  44 #include "mptext.h"
  45
  46 /*----- Reference counting stuff ------------------------------------------*/
  47
  48 /* --- @key_incref@ --- *
  49  *
  50  * Arguments:   @key_data *k@ = pointer to key data
  51  *
  52  * Returns:     ---
  53  *
  54  * Use:         Increments the refcount on a key data block.
  55  */
  56
  57 void key_incref(key_data *k) { KEY_INCREF(k); }
  58
  59 /* --- @key_destroy@ --- *
  60  *
  61  * Arguments:   @key_data *k@ = pointer to key data to destroy
  62  *
  63  * Returns:     ---
  64  *
  65  * Use:         Destroys a block of key data, regardless of reference count.
  66  *              Don't use this unless you know what you're doing.
  67  */
  68
  69 void key_destroy(key_data *k)
  70 {
  71   switch (k->e & KF_ENCMASK) {
  72     case KENC_BINARY:
  73     case KENC_ENCRYPT:
  74       if (k->u.k.k) {
  75         if (k->e & KF_BURN)
  76           memset(k->u.k.k, 0, k->u.k.sz);
  77         sub_free(k->u.k.k, k->u.k.sz);
  78       }
  79       break;
  80     case KENC_MP:
  81       mp_drop(k->u.m);
  82       break;
  83     case KENC_STRING:
  84       xfree(k->u.p);
  85       break;
  86     case KENC_EC:
  87       EC_DESTROY(&k->u.e);
  88       break;
  89     case KENC_STRUCT: {
  90       key_data *kd;
  91       key_subkeyiter i;
  92
  93       for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, 0, &kd); )
  94         KEY_DROP(kd);
  95       sym_destroy(&k->u.s);
  96     } break;
  97     default:
  98       abort();
  99   }
 100   DESTROY(k);
 101 }
 102
 103 /* --- @key_drop@ --- *
 104  *
 105  * Arguments:   @key_data *k@ = pointer to key data to destroy
 106  *
 107  * Returns:     ---
 108  *
 109  * Use:         Drops a reference to key data, destroying it if necessary.
 110  */
 111
 112 void key_drop(key_data *k) { KEY_DROP(k); }
 113
 114 /* --- @key_split@ --- *
 115  *
 116  * Arguments:   @key_data **kk@ = address of pointer to key data block
 117  *
 118  * Returns:     ---
 119  *
 120  * Use:         Replaces @*kk@ with a pointer to the same key data, but with
 121  *              just one reference.
 122  */
 123
 124 void key_split(key_data **kk)
 125 {
 126   key_data *k = *kk;
 127
 128   if (k->ref == 1)
 129     return;
 130   switch (k->e & KF_ENCMASK) {
 131     case KENC_BINARY:
 132       *kk = key_newbinary(k->e, k->u.k.k, k->u.k.sz);
 133       break;
 134     case KENC_ENCRYPT:
 135       *kk = key_newencrypted(k->e, k->u.k.k, k->u.k.sz);
 136       break;
 137     case KENC_MP:
 138       *kk = key_newmp(k->e, k->u.m);
 139       break;
 140     case KENC_STRING:
 141       *kk = key_newstring(k->e, k->u.p);
 142       break;
 143     case KENC_EC:
 144       *kk = key_newec(k->e, &k->u.e);
 145       break;
 146     case KENC_STRUCT: {
 147       key_subkeyiter i;
 148       const char *tag;
 149       key_data *kd;
 150
 151       *kk = key_newstruct();
 152       for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &kd); )
 153         key_structset(*kk, tag, kd);
 154     } break;
 155     default:
 156       abort();
 157   }
 158 }
 159
 160 /*----- Setting new values ------------------------------------------------*/
 161
 162 /* --- @key_newraw@ --- *
 163  *
 164  * Arguments:   @unsigned e@ = encoding type to set
 165  *
 166  * Returns:     New key block, not filled in.
 167  */
 168
 169 key_data *key_newraw(unsigned e)
 170 {
 171   key_data *k = CREATE(key_data);
 172   k->e = e;
 173   k->ref = 1;
 174   return (k);
 175 }
 176
 177 /* --- @key_newbinary@ --- *
 178  *
 179  * Arguments:   @unsigned e@ = other encoding flags
 180  *              @const void *p@ = pointer to key data
 181  *              @size_t sz@ = size of the key data
 182  *
 183  * Returns:     New key data object.
 184  */
 185
 186 key_data *key_newbinary(unsigned e, const void *p, size_t sz)
 187 {
 188   key_data *k = key_newraw(KENC_BINARY | e);
 189   k->u.k.k = sub_alloc(sz);
 190   memcpy(k->u.k.k, p, sz);
 191   k->u.k.sz = sz;
 192   return (k);
 193 }
 194
 195 /* --- @key_newencrypted@ --- *
 196  *
 197  * Arguments:   @unsigned e@ = other encoding flags
 198  *              @const void *p@ = pointer to key data
 199  *              @size_t sz@ = size of the key data
 200  *
 201  * Returns:     New key data object.
 202  */
 203
 204 key_data *key_newencrypted(unsigned e, const void *p, size_t sz)
 205 {
 206   key_data *k = key_newraw(KENC_ENCRYPT | e);
 207   k->u.k.k = sub_alloc(sz);
 208   memcpy(k->u.k.k, p, sz);
 209   k->u.k.sz = sz;
 210   return (k);
 211 }
 212
 213 /* --- @key_mewmp@ --- *
 214  *
 215  * Arguments:   @unsigned e@ = other encoding flags
 216  *              @mp *m@ = pointer to the value to set
 217  *
 218  * Returns:     New key data object.
 219  */
 220
 221 key_data *key_newmp(unsigned e, mp *m)
 222 {
 223   key_data *k = key_newraw(KENC_MP | e);
 224   k->u.m = MP_COPY(m);
 225   return (k);
 226 }
 227
 228 /* --- @key_newstring@ --- *
 229  *
 230  * Arguments:   @unsigned e@ = other encoding flags
 231  *              @const char *p@ = pointer to the value to set
 232  *
 233  * Returns:     New key data object.
 234  */
 235
 236 key_data *key_newstring(unsigned e, const char *p)
 237 {
 238   key_data *k = key_newraw(KENC_STRING | e);
 239   k->u.p = xstrdup(p);
 240   return (k);
 241 }
 242
 243 /* --- @key_newec@ --- *
 244  *
 245  * Arguments:   @unsigned e@ = other encoding flags
 246  *              @const ec *pt@ = pointer to the value to set
 247  *
 248  * Returns:     New key data object.
 249  */
 250
 251 key_data *key_newec(unsigned e, const ec *pt)
 252 {
 253   key_data *k = key_newraw(KENC_EC | e);
 254   EC_CREATE(&k->u.e);
 255   EC_COPY(&k->u.e, pt);
 256   return (k);
 257 }
 258
 259 /* --- @key_newstruct@ --- *
 260  *
 261  * Arguments:   ---
 262  *
 263  * Returns:     New key data object.
 264  */
 265
 266 key_data *key_newstruct(void)
 267 {
 268   key_data *k = key_newraw(KENC_STRUCT);
 269   sym_create(&k->u.s);
 270   return (k);
 271 }
 272
 273 /* --- @key_structfind@ --- *
 274  *
 275  * Arguments:   @key_data *k@ = pointer to key data block
 276  *              @const char *tag@ = pointer to tag string
 277  *
 278  * Returns:     Pointer to key data block, or null.
 279  *
 280  * Use:         Looks up the tag in a structured key.
 281  */
 282
 283 key_data *key_structfind(key_data *k, const char *tag)
 284 {
 285   key_struct *ks;
 286   assert(((void)"Key is not structured",
 287           (k->e & KF_ENCMASK) == KENC_STRUCT));
 288   ks = sym_find(&k->u.s, tag, -1, 0, 0);
 289   if (!ks)
 290     return (0);
 291   return (ks->k);
 292 }
 293
 294 /* --- @key_mksubkeyiter@ --- *
 295  *
 296  * Arguments:   @key_subkeyiter *i@ = pointer to iterator block
 297  *              @key_data *k@ = pointer to key data block
 298  *
 299  * Returns:     ---
 300  *
 301  * Use:         Initializes a subkey iterator.
 302  */
 303
 304 void key_mksubkeyiter(key_subkeyiter *i, key_data *k)
 305 {
 306   assert(((void)"Key is not structured",
 307           (k->e & KF_ENCMASK) == KENC_STRUCT));
 308   sym_mkiter(&i->i, &k->u.s);
 309 }
 310
 311 /* --- @key_nextsubkey@ --- *
 312  *
 313  * Arguments:   @key_structiter *i@ = pointer to iterator block
 314  *              @const char **tag@ = where to put the tag pointer, or null
 315  *              @key_data **kd@ = where to put the key data pointer, or null
 316  *
 317  * Returns:     Nonzero if there was another item, zero if we hit the
 318  *              end-stop.
 319  *
 320  * Use:         Collects the next subkey of a structured key.
 321  */
 322
 323 int key_nextsubkey(key_subkeyiter *i, const char **tag, key_data **kd)
 324 {
 325   key_struct *ks;
 326
 327   if ((ks = sym_next(&i->i)) == 0)
 328     return (0);
 329   if (tag) *tag = SYM_NAME(ks);
 330   if (kd) *kd = ks->k;
 331   return (1);
 332 }
 333
 334 /* --- @key_structset@, @key_structsteal@ --- *
 335  *
 336  * Arguments:   @key_data *k@ = pointer to key data block
 337  *              @const char *tag@ = pointer to tag string
 338  *              @key_data *kd@ = new key data to store
 339  *
 340  * Returns:     ---
 341  *
 342  * Use:         Creates a new subkey.  Stealing doesn't affect @kd@'s
 343  *              refcount.  If @kd@ is null, the subkey is deleted.
 344  */
 345
 346 static void structset(key_data *k, int stealp,
 347                       const char *tag, key_data *kd)
 348 {
 349   key_struct *ks;
 350   unsigned f;
 351
 352   assert(((void)"Key is not structured", k->e == KENC_STRUCT));
 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 /*----- That's all, folks -------------------------------------------------*/