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

   1 /* -*-c-*-
   2  *
   3  * Adding new keys to a key file
   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 <ctype.h>
  31 #include <errno.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <time.h>
  36
  37 #include <mLib/bits.h>
  38 #include <mLib/crc32.h>
  39 #include <mLib/dstr.h>
  40 #include <mLib/hash.h>
  41 #include <mLib/str.h>
  42 #include <mLib/sub.h>
  43 #include <mLib/sym.h>
  44 #include <mLib/url.h>
  45
  46 #include "key.h"
  47
  48 /*----- Tweakable macros --------------------------------------------------*/
  49
  50 #define KEY_INITSZ 16
  51
  52 /*----- Low-level functions -----------------------------------------------*/
  53
  54 /* --- @insert@ --- *
  55  *
  56  * Arguments:   @key_file *f@ = pointer to file structure
  57  *              @key *k@ = pointer to key block to insert
  58  *
  59  * Returns:     Error code (one of the @KERR@ code).
  60  *
  61  * Use:         Links a new key block into the complicated data structure
  62  *              which is a keyring file.
  63  */
  64
  65 static int insert(key_file *f, key *k)
  66 {
  67   key_ref *kr = 0;
  68   unsigned found;
  69
  70   /* --- Sanity preservatives --- */
  71
  72   if (key_chkident(k->type))
  73     return (KERR_BADTYPE);
  74   else if (k->tag && key_chkident(k->tag))
  75     return (KERR_BADTAG);
  76
  77   /* --- Insert into the tag table --- */
  78
  79   if (k->tag) {
  80     kr = sym_find(&f->bytag, k->tag, -1, sizeof(*kr), &found);
  81     if (found)
  82       return (KERR_DUPTAG);
  83     kr->k = k;
  84   }
  85
  86   /* --- Insert into the id table --- */
  87
  88   {
  89     hash_base **bin, *b;
  90
  91     bin = HASH_BIN(&f->byid, k->id);
  92     for (b = *bin; b; b = b->next) {
  93       if (b->hash == k->id) {
  94         if (kr)
  95           sym_remove(&f->bytag, kr);
  96         return (KERR_DUPID);
  97       }
  98     }
  99
 100     k->_b.next = *bin;
 101     *bin = &k->_b;
 102     k->_b.hash = k->id;
 103   }
 104
 105   /* --- Extend the table --- */
 106
 107   if (f->idload > 0)
 108     f->idload--;
 109   else if (hash_extend(&f->byid))
 110     f->idload = SYM_LIMIT(f->byid.mask / 2);
 111
 112   /* --- Insert into the type table --- */
 113
 114   kr = sym_find(&f->bytype, k->type, -1, sizeof(*kr), &found);
 115   if (!found) {
 116     kr->k = k;
 117     k->next = 0;
 118   } else {
 119     key **p = &kr->k;
 120     if (k->exp != KEXP_FOREVER) {
 121       while (*p && (*p)->exp != KEXP_EXPIRE && (*p)->exp > k->exp)
 122         p = &(*p)->next;
 123     }
 124     k->next = *p;
 125     *p = k;
 126   }
 127
 128   return (KERR_OK);
 129 }
 130
 131 /*----- Reading and writing keys ------------------------------------------*/
 132
 133 /* --- @exptime@ --- *
 134  *
 135  * Arguments:   @const char *p@ = pointer to string
 136  *
 137  * Returns:     Time value.
 138  *
 139  * Use:         Translates an expiry or deletion time.
 140  */
 141
 142 time_t exptime(const char *p)
 143 {
 144   size_t sz = strlen(p);
 145   if (strncmp(p, "expired", sz) == 0)
 146     return (KEXP_EXPIRE);
 147   else if (strncmp(p, "forever", sz) == 0)
 148     return (KEXP_FOREVER);
 149   else
 150     return (atol(p));
 151 }
 152
 153 /* --- @key_merge@ --- *
 154  *
 155  * Arguments:   @key_file *f@ = pointer to file structure
 156  *              @const char *file@ = name of file (for error messages)
 157  *              @FILE *fp@ = file handle to read from
 158  *              @key_reporter *rep@ = error reporting function
 159  *              @void *arg@ = argument for function
 160  *
 161  * Returns:     Error code (one of the @KERR@ constants).
 162  *
 163  * Use:         Reads keys from a file, and inserts them into the file.
 164  */
 165
 166 int key_merge(key_file *f, const char *file, FILE *fp,
 167               key_reporter *rep, void *arg)
 168 {
 169   int line = 0;
 170   dstr l = DSTR_INIT;
 171   dstr n = DSTR_INIT, v = DSTR_INIT;
 172
 173   if (!(f->f & KF_WRITE))
 174     return (KERR_READONLY);
 175
 176   for (; dstr_putline(&l, fp) != EOF; DRESET(&l)) {
 177     char *vf[6];
 178     char *p = l.buf;
 179     key *k;
 180
 181     /* --- Skip blank lines and comments --- *
 182      *
 183      * Quite what they're doing in what ought to be an automatically-
 184      * maintained file I don't know.
 185      */
 186
 187     line++;
 188     while (isspace((unsigned char)*p))
 189       p++;
 190     if (!*p || *p == '#')
 191       continue;
 192
 193     /* --- Break the line into fields --- *
 194      *
 195      * There are currently six fields of interest:
 196      *
 197      *   * The key's identification (id, tag and type).
 198      *   * The actual key data itself.
 199      *   * The key expiry time.
 200      *   * The key deletion time.
 201      *   * The attributes field.
 202      *   * Any further comments.
 203      *
 204      * All but the last field can contain no spaces.
 205      */
 206
 207     {
 208       int n = str_split(p, vf, 5, &vf[5]);
 209       if (n < 4) {
 210         if (rep)
 211           rep(file, line, "too few fields", arg);
 212         goto skip_0;
 213       }
 214     }
 215
 216     /* --- Allocate a new key block --- */
 217
 218     k = CREATE(key);
 219
 220     /* --- Extract the key data into the block --- */
 221
 222     if ((k->k = key_read(vf[1], 0)) == 0) {
 223       if (rep)
 224         rep(file, line, "bad key data", arg);
 225       goto skip_1;
 226     }
 227
 228     /* --- Decode the identification field --- *
 229      *
 230      * For compatibility, derive a keyid from the key data.  This can only be
 231      * done if the key encoding is binary (and presumably old-encoding binary
 232      * at that).
 233      */
 234
 235     {
 236       char *q = strchr(vf[0], ':');
 237       char *qq;
 238
 239       if (!q) {
 240         if (k->k->e != KENC_BINARY) {
 241           if (rep)
 242             rep(file, line, "new-style key encoding but no keyid", arg);
 243           goto skip_2;
 244         }
 245         k->id = crc32(0, k->k->u.k.k, k->k->u.k.sz);
 246         k->type = xstrdup(vf[0]);
 247         k->tag = 0;
 248       } else {
 249         *q++ = 0;
 250         k->id = strtoul(p, 0, 16);
 251         if ((qq = strchr(q, ':')) == 0 || !qq[1]) {
 252           if (qq)
 253             *qq = 0;
 254           k->tag = 0;
 255         } else {
 256           *qq++ = 0;
 257           k->tag = xstrdup(qq);
 258         }
 259         k->type = xstrdup(q);
 260       }
 261     }
 262
 263     /* --- Get a key block for the new key --- */
 264
 265     k->exp = exptime(vf[2]);
 266     k->del = exptime(vf[3]);
 267
 268     /* --- Insert the key block into the table --- */
 269
 270     {
 271       int err;
 272
 273     again:
 274       if ((err = insert(f, k)) < 0) {
 275         if (err == KERR_DUPTAG) {
 276           if (rep)
 277             rep(file, line, "duplicate key tag stripped", arg);
 278           xfree(k->tag);
 279           k->tag = 0;
 280           goto again;
 281         }
 282         if (rep)
 283           rep(file, line, key_strerror(err), arg);
 284         goto skip_3;
 285       }
 286     }
 287
 288     /* --- Parse up the attributes, if specified --- */
 289
 290     sym_create(&k->a);
 291     if (vf[4] && strcmp(vf[4], "-") != 0) {
 292       url_dctx uc;
 293       for (url_initdec(&uc, vf[4]); url_dec(&uc, &n, &v); ) {
 294         key_putattr(f, k, n.buf, v.buf);
 295         DRESET(&n); DRESET(&v);
 296       }
 297     }
 298
 299     /* --- Insert the comment --- */
 300
 301     if (vf[5])
 302       k->c = xstrdup(vf[5]);
 303     else
 304       k->c = 0;
 305     continue;
 306
 307     /* --- Tidy up after something going wrong --- */
 308
 309   skip_3:
 310     if (k->tag)
 311       xfree(k->tag);
 312     xfree(k->type);
 313   skip_2:
 314     key_drop(k->k);
 315   skip_1:
 316     DESTROY(k);
 317   skip_0:;
 318   }
 319
 320   /* --- Extensive tidying up now required --- */
 321
 322   dstr_destroy(&l);
 323   dstr_destroy(&n);
 324   dstr_destroy(&v);
 325   f->f |= KF_MODIFIED;
 326   return (0);
 327 }
 328
 329 /* --- @key_extract@ --- *
 330  *
 331  * Arguments:   @key_file *f@ = pointer to file structure
 332  *              @key *k@ = key to extract
 333  *              @FILE *fp@ = file to write on
 334  *              @const key_filter *kf@ = pointer to key selection block
 335  *
 336  * Returns:     Zero if OK, EOF on error.
 337  *
 338  * Use:         Extracts a key to an ouptut file.
 339  */
 340
 341 int key_extract(key_file *f, key *k, FILE *fp, const key_filter *kf)
 342 {
 343   dstr d = DSTR_INIT;
 344   time_t t = time(0);
 345
 346   /* --- Skip the key if it's deleted or unselected--- */
 347
 348   if (KEY_EXPIRED(t, k->del) || !key_match(k->k, kf))
 349     return (0);
 350
 351   /* --- Encode the key and write the easy stuff --- */
 352
 353   key_fulltag(k, &d);
 354   DPUTC(&d, ' ');
 355   key_write(k->k, &d, kf);
 356   DPUTC(&d, ' ');
 357   dstr_write(&d, fp);
 358   DRESET(&d);
 359
 360   /* --- Write out the expiry and deletion times --- */
 361
 362   if (KEY_EXPIRED(t, k->exp))
 363     fputs("expired ", fp);
 364   else if (k->exp == KEXP_FOREVER)
 365     fputs("forever ", fp);
 366   else
 367     fprintf(fp, "%li ", (long)k->exp);
 368
 369   if (k->del == KEXP_FOREVER)
 370     fputs("forever ", fp);
 371   else
 372     fprintf(fp, "%li ", (long)k->del);
 373
 374   /* --- Output the attributes --- */
 375
 376   {
 377     int none = 1;
 378     sym_iter i;
 379     key_attr *a;
 380     url_ectx uc;
 381
 382     url_initenc(&uc);
 383     for (sym_mkiter(&i, &k->a); (a = sym_next(&i)) != 0; ) {
 384       none = 0;
 385       url_enc(&uc, &d, SYM_NAME(a), a->p);
 386     }
 387     if (none)
 388       DPUTS(&d, "-");
 389     DWRITE(&d, fp);
 390   }
 391
 392   dstr_destroy(&d);
 393   if (k->c) {
 394     putc(' ', fp);
 395     fputs(k->c, fp);
 396   }
 397   putc('\n', fp);
 398   return (ferror(fp) ? EOF : 0);
 399 }
 400
 401 /*----- Opening and closing files -----------------------------------------*/
 402
 403 /* --- @key_open@ --- *
 404  *
 405  * Arguments:   @key_file *f@ = pointer to file structure to initialize
 406  *              @const char *file@ = pointer to the file name
 407  *              @unsigned how@ = opening options (@KOPEN_*@).
 408  *              @key_reporter *rep@ = error reporting function
 409  *              @void *arg@ = argument for function
 410  *
 411  * Returns:     Zero if it worked, nonzero otherwise.
 412  *
 413  * Use:         Opens a key file, reads its contents, and stores them in a
 414  *              structure.  The file is locked appropriately until closed
 415  *              using @key_close@.  On an error, everything is cleared away
 416  *              tidily.  If the file is opened with @KOPEN_WRITE@, it's
 417  *              created if necessary, with read and write permissions for its
 418  *              owner only.
 419  */
 420
 421 int key_open(key_file *f, const char *file, unsigned how,
 422              key_reporter *rep, void *arg)
 423 {
 424   if (key_lockfile(f, file, how)) {
 425     rep(file, 0, strerror(errno), arg);
 426     return (-1);
 427   }
 428   f->f = 0;
 429   f->name = xstrdup(file);
 430
 431   hash_create(&f->byid, KEY_INITSZ);
 432   f->idload = SYM_LIMIT(KEY_INITSZ);
 433   sym_create(&f->bytype);
 434   sym_create(&f->bytag);
 435   f->f |= KF_WRITE;
 436   if (f->fp)
 437     key_merge(f, file, f->fp, rep, arg);
 438   f->f &= ~KF_MODIFIED;
 439
 440   if ((how & KOPEN_MASK) == KOPEN_READ) {
 441     f->f &= ~KF_WRITE;
 442     fclose(f->fp);
 443     f->fp = 0;
 444   }
 445
 446   return (0);
 447 }
 448
 449 /* --- @key_discard@ --- *
 450  *
 451  * Arguments:   @key_file *f@ = pointer to key file block
 452  *
 453  * Returns:     ---
 454  *
 455  * Use:         Frees all the key data, without writing changes.
 456  */
 457
 458 void key_discard(key_file *f)
 459 {
 460   hash_base *b;
 461   hash_iter i;
 462
 463   /* --- Free all the individual keys --- */
 464
 465   for (hash_mkiter(&i, &f->byid); (b = hash_next(&i)) != 0; ) {
 466     sym_iter j;
 467     key_attr *a;
 468     key *k = (key *)b;
 469
 470     if (k->k) key_drop(k->k);
 471     xfree(k->type);
 472     xfree(k->tag);
 473     if (k->c)
 474       xfree(k->c);
 475     for (sym_mkiter(&j, &k->a); (a = sym_next(&j)) != 0; )
 476       xfree(a->p);
 477     sym_destroy(&k->a);
 478     DESTROY(k);
 479   }
 480   hash_destroy(&f->byid);
 481   sym_destroy(&f->bytype);
 482   sym_destroy(&f->bytag);
 483
 484   if (f->fp)
 485     fclose(f->fp);
 486   xfree(f->name);
 487 }
 488
 489 /* --- @key_close@ --- *
 490  *
 491  * Arguments:   @key_file *f@ = pointer to key file block
 492  *
 493  * Returns:     A @KWRITE_@ code indicating how it went.
 494  *
 495  * Use:         Frees all the key data, writes any changes.  Make sure that
 496  *              all hell breaks loose if this returns @KWRITE_BROKEN@.
 497  */
 498
 499 int key_close(key_file *f)
 500 {
 501   int e;
 502
 503   if (f->fp && (e = key_save(f)) != KWRITE_OK)
 504     return (e);
 505   key_discard(f);
 506   return (KWRITE_OK);
 507 }
 508
 509 /* --- @key_new@ ---
 510  *
 511  * Arguments:   @key_file *f@ = pointer to key file
 512  *              @uint32 id@ = keyid to set
 513  *              @const char *type@ = the type of this key
 514  *              @time_t exp@ = when the key expires
 515  *              @key *kk@ = where to put the key pointer
 516  *
 517  * Returns:     Error code (one of the @KERR@ constants).
 518  *
 519  * Use:         Attaches a new key to a key file.  You must have a writable
 520  *              key file for this to work.
 521  *
 522  *              The type is a key type string.  This interface doesn't care
 523  *              about how type strings are formatted: it just treats them as
 524  *              opaque gobs of text.  Clients are advised to choose some
 525  *              standard for representing key types, though.
 526  *
 527  *              The expiry time should either be a time in the future, or the
 528  *              magic value @KEXP_FOREVER@ which means `never expire this
 529  *              key'.  Be careful with `forever' keys.  If I were you, I'd
 530  *              use a more sophisticated key management system than this for
 531  *              them.
 532  */
 533
 534 int key_new(key_file *f, uint32 id, const char *type, time_t exp, key **kk)
 535 {
 536   key *k = 0;
 537   time_t t = time(0);
 538   int e = KERR_OK;
 539
 540   /* --- Make sure the file is writable --- */
 541
 542   if (!(f->f & KF_WRITE))
 543     e = KERR_READONLY;
 544   else if (KEY_EXPIRED(t, exp))
 545     e = KERR_EXPIRED;
 546   else if (key_chkident(type))
 547     e = KERR_BADTYPE;
 548   else {
 549     k = CREATE(key);
 550     k->id = id;
 551     k->tag = 0;
 552     k->exp = k->del = exp;
 553     k->c = 0;
 554     k->type = (char *)type; /* temporarily */
 555     sym_create(&k->a);
 556     if ((e = insert(f, k)) != 0)
 557       DESTROY(k);
 558     else {
 559       k->k = key_newstring(KCAT_SHARE, "<unset>");
 560       k->type = xstrdup(type);
 561       *kk = k;
 562       f->f |= KF_MODIFIED;
 563     }
 564   }
 565
 566   return (e);
 567 }
 568
 569 /*----- That's all, folks -------------------------------------------------*/