| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: key.h,v 1.1 1999/09/03 08:41:12 mdw Exp $ |
| 4 | * |
| 5 | * Simple key management |
| 6 | * |
| 7 | * (c) 1999 Mark Wooding |
| 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.h,v $ |
| 33 | * Revision 1.1 1999/09/03 08:41:12 mdw |
| 34 | * Initial import. |
| 35 | * |
| 36 | */ |
| 37 | |
| 38 | #ifndef KEY_H |
| 39 | #define KEY_H |
| 40 | |
| 41 | #ifdef __cplusplus |
| 42 | extern "C" { |
| 43 | #endif |
| 44 | |
| 45 | /*----- Header files ------------------------------------------------------*/ |
| 46 | |
| 47 | #include <stdio.h> |
| 48 | #include <time.h> |
| 49 | |
| 50 | #include <mLib/bits.h> |
| 51 | #include <mLib/hash.h> |
| 52 | #include <mLib/sym.h> |
| 53 | |
| 54 | /*----- Data structures ---------------------------------------------------*/ |
| 55 | |
| 56 | /* --- Key attributes --- * |
| 57 | * |
| 58 | * Each attribute is stored as a symbol in a symbol table. The value is |
| 59 | * the plain (not url-encoded) text to be written to the the file. If the |
| 60 | * value is binary data, then by this point it's base-64 encoded. |
| 61 | */ |
| 62 | |
| 63 | typedef struct key_attr { |
| 64 | sym_base _b; /* Symbol table data */ |
| 65 | char *p; /* Pointer to attribute value */ |
| 66 | } key_attr; |
| 67 | |
| 68 | /* --- Main key structure --- * |
| 69 | * |
| 70 | * Each key is stored in two symbol tables, one indexed by keyid, and the |
| 71 | * other indexed by type. Because many keys can have the same type, the type |
| 72 | * table contains a list of keys, sorted in descending order of expiry. |
| 73 | */ |
| 74 | |
| 75 | typedef struct key { |
| 76 | hash_base _b; /* Symbol table data */ |
| 77 | struct key *next; /* Next key of the same type */ |
| 78 | uint32 id; /* Key id used to name it */ |
| 79 | char *type; /* Textual key type */ |
| 80 | void *k; /* Actual key data */ |
| 81 | size_t ksz; /* Size of the key data */ |
| 82 | time_t exp, del; /* Expiry times for keys */ |
| 83 | sym_table a; /* Hashtable of key attributes */ |
| 84 | char *c; /* Any additional comments */ |
| 85 | } key; |
| 86 | |
| 87 | /* --- The keys-by-type entries --- */ |
| 88 | |
| 89 | typedef struct key_type { |
| 90 | sym_base _b; /* Symbol table data */ |
| 91 | key *k; /* Pointer to first key in list */ |
| 92 | } key_type; |
| 93 | |
| 94 | /* --- A key file --- */ |
| 95 | |
| 96 | typedef struct key_file { |
| 97 | FILE *fp; /* File pointer open on file */ |
| 98 | int fd; /* File descriptor open on file */ |
| 99 | char *name; /* Filename used to create it */ |
| 100 | unsigned f; /* Various useful flags */ |
| 101 | hash_table byid; /* Table of keys by keyid */ |
| 102 | sym_table bytype; /* Table of keys by type */ |
| 103 | size_t idload; /* Loading on id table */ |
| 104 | } key_file; |
| 105 | |
| 106 | /* --- Key file flags --- */ |
| 107 | |
| 108 | enum { |
| 109 | KF_WRITE = 1, /* File opened for writing */ |
| 110 | KF_MODIFIED = 2 /* File has been modified */ |
| 111 | }; |
| 112 | |
| 113 | /* --- Iterating over keys --- * |
| 114 | * |
| 115 | * Both of these are simple symbol table iterators, but they're made distinct |
| 116 | * types for the dubious benefits that type safety brings. |
| 117 | */ |
| 118 | |
| 119 | typedef struct { hash_iter i; time_t t; } key_iter; |
| 120 | typedef struct { sym_iter i; } key_attriter; |
| 121 | |
| 122 | /* --- File opening options --- */ |
| 123 | |
| 124 | enum { |
| 125 | KOPEN_READ, |
| 126 | KOPEN_WRITE |
| 127 | }; |
| 128 | |
| 129 | /* --- Various other magic numbers --- */ |
| 130 | |
| 131 | #define KEXP_UNUSED ((time_t)0) /* Key has never been used */ |
| 132 | #define KEXP_FOREVER ((time_t)-1) /* Never expire this key */ |
| 133 | #define KEXP_EXPIRE ((time_t)-2) /* Expire this key when unused */ |
| 134 | |
| 135 | /* --- Write attempt codes --- */ |
| 136 | |
| 137 | enum { |
| 138 | KWRITE_OK, /* Everything went fine */ |
| 139 | KWRITE_FAIL = -1, /* Close attempt failed */ |
| 140 | KWRITE_BROKEN = -2 /* Key ring needs manual fixing */ |
| 141 | }; |
| 142 | |
| 143 | /* --- Macros for testing expiry --- */ |
| 144 | |
| 145 | #define KEY_EXPIRED(now, exp) \ |
| 146 | ((exp) == KEXP_EXPIRE || ((exp) != KEXP_FOREVER && (exp) < (now))) |
| 147 | |
| 148 | #define KEY_DELETED(now, del) ((del) == KEXP_FOREVER || (del) < (now)) |
| 149 | |
| 150 | /*----- Functions provided ------------------------------------------------*/ |
| 151 | |
| 152 | /* --- @key_chktype@ --- * |
| 153 | * |
| 154 | * Arguments: @const char *type@ = pointer to a type string |
| 155 | * |
| 156 | * Returns: Zero if OK, -1 on error. |
| 157 | * |
| 158 | * Use: Checks whether a type string is OK. |
| 159 | */ |
| 160 | |
| 161 | extern int key_chktype(const char */*type*/); |
| 162 | |
| 163 | /* --- @key_chkcomment@ --- * |
| 164 | * |
| 165 | * Arguments: @const char *comment@ = pointer to a comment string |
| 166 | * |
| 167 | * Returns: Zero if OK, -1 on error. |
| 168 | * |
| 169 | * Use: Checks whether a comment string is OK. |
| 170 | */ |
| 171 | |
| 172 | extern int key_chkcomment(const char */*c*/); |
| 173 | |
| 174 | /* --- @key_mkiter@ --- * |
| 175 | * |
| 176 | * Arguments: @key_iter *i@ = pointer to iterator object |
| 177 | * @key_file *f@ = pointer to file structure |
| 178 | * |
| 179 | * Returns: --- |
| 180 | * |
| 181 | * Use: Initializes a key iterator. The keys are returned by |
| 182 | * @key_next@. |
| 183 | */ |
| 184 | |
| 185 | extern void key_mkiter(key_iter */*i*/, key_file */*f*/); |
| 186 | |
| 187 | /* --- @key_next@ --- * |
| 188 | * |
| 189 | * Arguments: @key_iter *i@ = pointer to iterator object |
| 190 | * |
| 191 | * Returns: Pointer to next key, or null. |
| 192 | * |
| 193 | * Use: Returns the next key in some arbitrary sequence. |
| 194 | */ |
| 195 | |
| 196 | extern key *key_next(key_iter */*i*/); |
| 197 | |
| 198 | /* --- @key_mkattriter@ --- * |
| 199 | * |
| 200 | * Arguments: @key_attriter *i@ = pointer to attribute iterator |
| 201 | * @key_file *f@ = pointer to key file |
| 202 | * @key *k@ = pointer to key |
| 203 | * |
| 204 | * Returns: --- |
| 205 | * |
| 206 | * Use: Initializes an attribute iterator. The attributes are |
| 207 | * returned by @key_nextattr@. |
| 208 | */ |
| 209 | |
| 210 | extern void key_mkattriter(key_attriter */*i*/, key_file */*f*/, key */*k*/); |
| 211 | |
| 212 | /* --- @key_nextattr@ --- * |
| 213 | * |
| 214 | * Arguments: @key_attriter *i@ = pointer to attribute iterator |
| 215 | * @const char **n, **v@ = pointers to name and value |
| 216 | * |
| 217 | * Returns: Zero if no attribute available, or nonzero if returned OK. |
| 218 | * |
| 219 | * Use: Returns the next attribute. |
| 220 | */ |
| 221 | |
| 222 | extern int key_nextattr(key_attriter */*i*/, |
| 223 | const char **/*n*/, const char **/*v*/); |
| 224 | |
| 225 | /* --- @key_bytype@ --- * |
| 226 | * |
| 227 | * Arguments: @key_file *f@ = key file we want a key from |
| 228 | * @const char *type@ = type string for desired key |
| 229 | * |
| 230 | * Returns: Pointer to the best key to use, or null. |
| 231 | * |
| 232 | * Use: Looks up a key by its type. Returns the key with the latest |
| 233 | * expiry time. This function will not return an expired key. |
| 234 | */ |
| 235 | |
| 236 | extern key *key_bytype(key_file */*f*/, const char */*type*/); |
| 237 | |
| 238 | /* --- @key_byid@ --- * |
| 239 | * |
| 240 | * Arguments: @key_file *f@ = key file to find a key from |
| 241 | * @uint32 id@ = id to look for |
| 242 | * |
| 243 | * Returns: Key with matching id. |
| 244 | * |
| 245 | * Use: Returns a key given its id. This function will return an |
| 246 | * expired key, but not a deleted one. |
| 247 | */ |
| 248 | |
| 249 | extern key *key_byid(key_file */*f*/, uint32 /*id*/); |
| 250 | |
| 251 | /* --- @key_getattr@ --- * |
| 252 | * |
| 253 | * Arguments: @key_file *f@ = pointer to file |
| 254 | * @key *k@ = pointer to key |
| 255 | * @const char *n@ = pointer to attribute name |
| 256 | * |
| 257 | * Returns: Pointer to attribute value, or null if not found. |
| 258 | * |
| 259 | * Use: Returns the value of a key attribute. |
| 260 | */ |
| 261 | |
| 262 | extern const char *key_getattr(key_file */*f*/, key */*k*/, |
| 263 | const char */*n*/); |
| 264 | |
| 265 | /* --- @key_putattr@ --- * |
| 266 | * |
| 267 | * Arguments: @key_file *f@ = pointer to file |
| 268 | * @key *k@ = pointer to key |
| 269 | * @const char *n@ = pointer to attribute name |
| 270 | * @const char *v@ = pointer to attribute value |
| 271 | * |
| 272 | * Returns: --- |
| 273 | * |
| 274 | * Use: Inserts an attribute on a key. If an attribute with the same |
| 275 | * name already exists, it is deleted. |
| 276 | */ |
| 277 | |
| 278 | extern void key_putattr(key_file */*f*/, key */*k*/, |
| 279 | const char */*n*/, const char */*v*/); |
| 280 | |
| 281 | /* --- @key_setcomment@ --- * |
| 282 | * |
| 283 | * Arguments: @key_file *f@ = pointer to key file block |
| 284 | * @key *k@ = pointer to key block |
| 285 | * @const char *c@ = pointer to comment to set, or zero |
| 286 | * |
| 287 | * Returns: --- |
| 288 | * |
| 289 | * Use: Replaces the key's current comment with a new one. |
| 290 | */ |
| 291 | |
| 292 | extern void key_setcomment(key_file */*f*/, key */*k*/, const char */*c*/); |
| 293 | |
| 294 | /* --- @key_merge@ --- * |
| 295 | * |
| 296 | * Arguments: @key_file *f@ = pointer to file structure |
| 297 | * @const char *file@ = name of file (for error messages) |
| 298 | * @FILE *fp@ = file handle to read from |
| 299 | * |
| 300 | * Returns: --- |
| 301 | * |
| 302 | * Use: Reads keys from a file, and inserts them into the file. |
| 303 | */ |
| 304 | |
| 305 | extern void key_merge(key_file */*f*/, const char */*file*/, FILE */*fp*/); |
| 306 | |
| 307 | /* --- @key_extract@ --- * |
| 308 | * |
| 309 | * Arguments: @key_file *f@ = pointer to file structure |
| 310 | * @key *k@ = key to extract |
| 311 | * @FILE *fp@ = file to write on |
| 312 | * |
| 313 | * Returns: Zero if OK, EOF on error. |
| 314 | * |
| 315 | * Use: Extracts a key to an ouptut file. |
| 316 | */ |
| 317 | |
| 318 | extern int key_extract(key_file */*f*/, key */*k*/, FILE */*fp*/); |
| 319 | |
| 320 | /* --- @key_write@ --- * |
| 321 | * |
| 322 | * Arguments: @key_file *f@ = pointer to key file block |
| 323 | * |
| 324 | * Returns: A @KWRITE_@ code indicating how well it worked. |
| 325 | * |
| 326 | * Use: Writes a key file's data back to the actual file. This code |
| 327 | * is extremely careful about error handling. It should usually |
| 328 | * be able to back out somewhere sensible, but it can tell when |
| 329 | * it's got itself into a real pickle and starts leaving well |
| 330 | * alone. |
| 331 | * |
| 332 | * Callers, please make sure that you ring alarm bells when this |
| 333 | * function returns @KWRITE_BROKEN@. |
| 334 | */ |
| 335 | |
| 336 | extern int key_write(key_file */*f*/); |
| 337 | |
| 338 | /* --- @key_open@ --- * |
| 339 | * |
| 340 | * Arguments: @key_file *f@ = pointer to file structure to initialize |
| 341 | * @const char *file@ = pointer to the file name |
| 342 | * @int how@ = opening options (@KOPEN_*@). |
| 343 | * |
| 344 | * Returns: Zero if it worked, nonzero otherwise. |
| 345 | * |
| 346 | * Use: Opens a key file, reads its contents, and stores them in a |
| 347 | * structure. The file is locked appropriately until closed |
| 348 | * using @key_close@. On an error, everything is cleared away |
| 349 | * tidily. If the file is opened with @KOPEN_WRITE@, it's |
| 350 | * created if necessary, with read and write permissions for its |
| 351 | * owner only. |
| 352 | */ |
| 353 | |
| 354 | extern int key_open(key_file */*f*/, const char */*file*/, int /*how*/); |
| 355 | |
| 356 | /* --- @key_close@ --- * |
| 357 | * |
| 358 | * Arguments: @key_file *f@ = pointer to key file block |
| 359 | * |
| 360 | * Returns: A @KWRITE_@ code indicating how it went. |
| 361 | * |
| 362 | * Use: Frees all the key data, writes any changes. Make sure that |
| 363 | * all hell breaks loose if this returns @KWRITE_BROKEN@. |
| 364 | */ |
| 365 | |
| 366 | extern int key_close(key_file */*f*/); |
| 367 | |
| 368 | /* --- @key_new@ --- |
| 369 | * |
| 370 | * Arguments: @key_file *f@ = pointer to key file |
| 371 | * @const char *type@ = the type of this key |
| 372 | * @const void *k@ = pointer to key data |
| 373 | * @size_t ksz@ = size of key data |
| 374 | * @time_t exp@ = when the key expires |
| 375 | * @const char *c@ = textual comment to attach |
| 376 | * |
| 377 | * Returns: Key block containing new data, or null if it couldn't be |
| 378 | * done. |
| 379 | * |
| 380 | * Use: Attaches a new key to a key file. You must have a writable |
| 381 | * key file for this to work. |
| 382 | * |
| 383 | * The type is a key type string. This interface doesn't care |
| 384 | * about how type strings are formatted: it just treats them as |
| 385 | * opaque gobs of text. Clients are advised to choose some |
| 386 | * standard for representing key types, though. |
| 387 | * |
| 388 | * The key can be any old binary mess. |
| 389 | * |
| 390 | * The expiry time should either be a time in the future, or the |
| 391 | * magic value @KEXP_FOREVER@ which means `never expire this |
| 392 | * key'. Be careful with `forever' keys. If I were you, I'd |
| 393 | * use a more sophisticated key management system than this for |
| 394 | * them. |
| 395 | * |
| 396 | * The comment can be any old text not containing newlines or |
| 397 | * nulls. This interface doesn't impose any length restrictions |
| 398 | * on comment lengths. |
| 399 | */ |
| 400 | |
| 401 | extern key *key_new(key_file */*f*/, const char */*type*/, |
| 402 | const void */*k*/, size_t /*ksz*/, |
| 403 | time_t /*exp*/, const char */*c*/); |
| 404 | |
| 405 | /* --- @key_delete@ --- * |
| 406 | * |
| 407 | * Arguments: @key_file *f@ = pointer to file block |
| 408 | * @key *k@ = key to delete |
| 409 | * |
| 410 | * Returns: --- |
| 411 | * |
| 412 | * Use: Removes the given key from the list. The key file must be |
| 413 | * writable. (Due to the horridness of the data structures, |
| 414 | * deleted keys aren't actually removed, just marked so that |
| 415 | * they can't be looked up or iterated over. One upshot of |
| 416 | * this is that they don't get written back to the file when |
| 417 | * it's closed.) |
| 418 | */ |
| 419 | |
| 420 | extern void key_delete(key_file */*f*/, key */*k*/); |
| 421 | |
| 422 | /* --- @key_expire@ --- * |
| 423 | * |
| 424 | * Arguments: @key_file *f@ = pointer to file block |
| 425 | * @key *k@ = pointer to key block |
| 426 | * |
| 427 | * Returns: --- |
| 428 | * |
| 429 | * Use: Immediately marks the key as expired. It may be removed |
| 430 | * immediately, if it is no longer required, and will be removed |
| 431 | * by a tidy operation when it is no longer required. The key |
| 432 | * file must be writable. |
| 433 | */ |
| 434 | |
| 435 | extern void key_expire(key_file */*f*/, key */*k*/); |
| 436 | |
| 437 | /* --- @key_used@ --- * |
| 438 | * |
| 439 | * Arguments: @key_file *f@ = pointer to key file |
| 440 | * @key *k@ = pointer to key block |
| 441 | * @time_t t@ = when key can be removed |
| 442 | * |
| 443 | * Returns: Zero if OK, nonzero on failure. |
| 444 | * |
| 445 | * Use: Marks a key as being required until a given time. Even |
| 446 | * though the key may expire before then (and won't be returned |
| 447 | * by type after that time), it will still be available when |
| 448 | * requested explicitly by id. The key file must be writable. |
| 449 | * |
| 450 | * The only (current) reason for failure is attempting to use |
| 451 | * a key which can expire for something which can't. |
| 452 | */ |
| 453 | |
| 454 | extern int key_used(key_file */*f*/, key */*k*/, time_t /*t*/); |
| 455 | |
| 456 | /*----- That's all, folks -------------------------------------------------*/ |
| 457 | |
| 458 | #ifdef __cplusplus |
| 459 | } |
| 460 | #endif |
| 461 | |
| 462 | #endif |