5 * Simple key management
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
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.
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.
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,
30 #ifndef CATACOMB_KEY_H
31 #define CATACOMB_KEY_H
37 /*----- Header files ------------------------------------------------------*/
42 #include <mLib/bits.h>
43 #include <mLib/dstr.h>
44 #include <mLib/hash.h>
47 #ifndef CATACOMB_KEY_ERROR_H
48 # include "key-error.h"
51 #ifndef CATACOMB_KEY_DATA_H
52 # include "key-data.h"
55 #ifndef CATACOMB_GHASH_H
63 /*----- Data structures ---------------------------------------------------*/
65 /* --- Key attributes --- *
67 * Each attribute is stored as a symbol in a symbol table. The value is
68 * the plain (not url-encoded) text to be written to the the file. If the
69 * value is binary data, then by this point it's base-64 encoded.
72 typedef struct key_attr
{
73 sym_base _b
; /* Symbol table data */
74 char *p
; /* Pointer to attribute value */
77 /* --- Main key structure --- *
79 * Each key is stored in two symbol tables, one indexed by keyid, and the
80 * other indexed by type. Because many keys can have the same type, the type
81 * table contains a list of keys, sorted in descending order of expiry.
86 /* --- Hashtable management --- */
88 hash_base _b
; /* Symbol table data */
89 struct key
*next
; /* Next key of the same type */
91 /* --- Basic key attributes --- */
93 uint32 id
; /* Key id used to name it */
94 char *tag
; /* Textual tag name */
95 char *type
; /* Textual key type */
96 time_t exp
, del
; /* Expiry times for keys */
98 /* --- The key data itself --- */
100 key_data k
; /* The actual key data */
102 /* --- Other attributes and commentary --- */
104 sym_table a
; /* Hashtable of key attributes */
105 char *c
; /* Any additional comments */
108 /* --- The keys-by-type entries --- */
110 typedef struct key_ref
{
111 sym_base _b
; /* Symbol table data */
112 key
*k
; /* Pointer to first key in list */
115 /* --- A key file --- */
117 typedef struct key_file
{
118 FILE *fp
; /* File pointer open on file */
119 char *name
; /* Filename used to create it */
120 unsigned f
; /* Various useful flags */
121 hash_table byid
; /* Table of keys by keyid */
122 sym_table bytype
; /* Table of keys by type */
123 sym_table bytag
; /* Table of keys by tag */
124 size_t idload
; /* Loading on id table */
127 /* --- Key file flags --- */
129 #define KF_WRITE 1u /* File opened for writing */
130 #define KF_MODIFIED 2u /* File has been modified */
132 /* --- Iterating over keys --- *
134 * Both of these are simple symbol table iterators, but they're made distinct
135 * types for the dubious benefits that type safety brings.
138 typedef struct { hash_iter i
; time_t t
; } key_iter
;
139 typedef struct { sym_iter i
; } key_attriter
;
141 /* --- Key fetching --- */
143 typedef struct key_fetchdef
{
144 char *name
; /* Name of item */
145 size_t off
; /* Offset into target structure */
146 unsigned e
; /* Flags for the item */
147 const struct key_fetchdef
*kf
; /* Substructure pointer */
150 /* --- File opening options --- */
152 #define KOPEN_READ 0u
153 #define KOPEN_WRITE 1u
154 #define KOPEN_MASK 0xff
155 #define KOPEN_NOFILE 0x100
157 /* --- Various other magic numbers --- */
159 #define KEXP_FOREVER ((time_t)-1) /* Never expire this key */
160 #define KEXP_EXPIRE ((time_t)-2) /* Expire this key when unused */
162 /* --- Write error codes --- */
165 KWRITE_OK
, /* Everything went fine */
166 KWRITE_FAIL
= -1, /* Close attempt failed */
167 KWRITE_BROKEN
= -2 /* Key ring needs manual fixing */
170 /* --- Error reporting functions for @key_merge@ and @key_open@ --- */
172 typedef void key_reporter(const char */
*file*/
, int /*line*/,
173 const char */
*err*/
, void */
*p*/
);
175 /* --- Macros for testing expiry --- */
177 #define KEY_EXPIRED(now, exp) \
178 ((exp) == KEXP_EXPIRE || ((exp) != KEXP_FOREVER && (exp) < (now)))
180 /*----- Reading and writing keys and files --------------------------------*/
182 /* --- @key_merge@ --- *
184 * Arguments: @key_file *f@ = pointer to file structure
185 * @const char *file@ = name of file (for error messages)
186 * @FILE *fp@ = file handle to read from
187 * @key_reporter *rep@ = error reporting function
188 * @void *arg@ = argument for function
190 * Returns: Error code (one of the @KERR@ constants).
192 * Use: Reads keys from a file, and inserts them into the file.
195 extern int key_merge(key_file */
*f*/
, const char */
*file*/
, FILE */
*fp*/
,
196 key_reporter */
*rep*/
, void */
*arg*/
);
198 /* --- @key_extract@ --- *
200 * Arguments: @key_file *f@ = pointer to file structure
201 * @key *k@ = key to extract
202 * @FILE *fp@ = file to write on
203 * @const key_filter *kf@ = pointer to key selection block
205 * Returns: Zero if OK, EOF on error.
207 * Use: Extracts a key to an ouptut file.
210 extern int key_extract(key_file */
*f*/
, key */
*k*/
, FILE */
*fp*/
,
211 const key_filter */
*kf*/
);
213 /* --- @key_open@ --- *
215 * Arguments: @key_file *f@ = pointer to file structure to initialize
216 * @const char *file@ = pointer to the file name
217 * @unsigned how@ = opening options (@KOPEN_*@).
218 * @key_reporter *rep@ = error reporting function
219 * @void *arg@ = argument for function
221 * Returns: Zero if it worked, nonzero otherwise.
223 * Use: Opens a key file, reads its contents, and stores them in a
224 * structure. The file is locked appropriately until closed
225 * using @key_close@. On an error, everything is cleared away
226 * tidily. If the file is opened with @KOPEN_WRITE@, it's
227 * created if necessary, with read and write permissions for its
231 extern int key_open(key_file */
*f*/
, const char */
*file*/
, unsigned /*how*/,
232 key_reporter */
*rep*/
, void */
*arg*/
);
234 /* --- @key_discard@ --- *
236 * Arguments: @key_file *f@ = pointer to key file block
240 * Use: Frees all the key data, without writing changes.
243 extern int key_discard(key_file */
*f*/
);
245 /* --- @key_close@ --- *
247 * Arguments: @key_file *f@ = pointer to key file block
249 * Returns: A @KWRITE_@ code indicating how it went.
251 * Use: Frees all the key data, writes any changes. Make sure that
252 * all hell breaks loose if this returns @KWRITE_BROKEN@.
255 extern int key_close(key_file */
*f*/
);
257 /* --- @key_save@ --- *
259 * Arguments: @key_file *f@ = pointer to key file block
261 * Returns: A @KWRITE_@ code indicating how well it worked.
263 * Use: Writes a key file's data back to the actual file. This code
264 * is extremely careful about error handling. It should usually
265 * be able to back out somewhere sensible, but it can tell when
266 * it's got itself into a real pickle and starts leaving well
269 * Callers, please make sure that you ring alarm bells when this
270 * function returns @KWRITE_BROKEN@.
273 extern int key_save(key_file */
*f*/
);
275 /* --- @key_lockfile@ --- *
277 * Arguments: @key_file *f@ = pointer to file structure to initialize
278 * @const char *file@ = pointer to the file name
279 * @unsigned how@ = opening options (@KOPEN_*@).
281 * Returns: Zero if it worked, nonzero otherwise.
283 * Use: Opens a keyfile and stores the information needed for
284 * continued access in the structure.
286 * If the file is opened with @KOPEN_WRITE@, it's created if
287 * necessary with read and write permissions for owner only, and
288 * locked for update while it's open.
290 * This is a system-dependent routine, and only really intended
291 * for the private use of @key_open@.
294 extern int key_lockfile(key_file */
*f*/
, const char */
*file*/
,
297 /*----- Creating and manipulating keys ------------------------------------*/
301 * Arguments: @key_file *f@ = pointer to key file
302 * @uint32 id@ = keyid to set
303 * @const char *type@ = the type of this key
304 * @time_t exp@ = when the key expires
305 * @int *err@ = where to store the error condition
307 * Returns: Key block containing new data, or null if it couldn't be
310 * Use: Attaches a new key to a key file. You must have a writable
311 * key file for this to work.
313 * The type is a key type string. This interface doesn't care
314 * about how type strings are formatted: it just treats them as
315 * opaque gobs of text. Clients are advised to choose some
316 * standard for representing key types, though.
318 * The expiry time should either be a time in the future, or the
319 * magic value @KEXP_FOREVER@ which means `never expire this
320 * key'. Be careful with `forever' keys. If I were you, I'd
321 * use a more sophisticated key management system than this for
324 * You have to set the actual key yourself.
327 extern key
*key_new(key_file */
*f*/
, uint32
/*id*/, const char */
*type*/
,
328 time_t /*exp*/, int */
*err*/
);
330 /* --- @key_delete@ --- *
332 * Arguments: @key_file *f@ = pointer to file block
333 * @key *k@ = key to delete
335 * Returns: Error code (one of the @KERR@ constants).
337 * Use: Removes the given key from the list. The key file must be
338 * writable. (Due to the horridness of the data structures,
339 * deleted keys aren't actually removed, just marked so that
340 * they can't be looked up or iterated over. One upshot of
341 * this is that they don't get written back to the file when
345 extern int key_delete(key_file */
*f*/
, key */
*k*/
);
347 /* --- @key_expired@ --- *
349 * Arguments: @key *k@ = pointer to key block
351 * Returns: Zero if the key is OK, nonzero if it's expired.
354 int key_expired(key */
*k*/
);
356 /* --- @key_expire@ --- *
358 * Arguments: @key_file *f@ = pointer to file block
359 * @key *k@ = pointer to key block
361 * Returns: Error code (one of the @KERR@ constants).
363 * Use: Immediately marks the key as expired. It may be removed
364 * immediately, if it is no longer required, and will be removed
365 * by a tidy operation when it is no longer required. The key
366 * file must be writable.
369 extern int key_expire(key_file */
*f*/
, key */
*k*/
);
371 /* --- @key_used@ --- *
373 * Arguments: @key_file *f@ = pointer to key file
374 * @key *k@ = pointer to key block
375 * @time_t t@ = when key can be removed
377 * Returns: Zero if OK, nonzero on failure.
379 * Use: Marks a key as being required until a given time. Even
380 * though the key may expire before then (and won't be returned
381 * by type after that time), it will still be available when
382 * requested explicitly by id. The key file must be writable.
384 * The only (current) reason for failure is attempting to use
385 * a key which can expire for something which can't.
388 extern int key_used(key_file */
*f*/
, key */
*k*/
, time_t /*t*/);
390 /* --- @key_fingerprint@ --- *
392 * Arguments: @key *k@ = the key to fingerprint
393 * @ghash *h@ = the hash to use
394 * @const key_filter *kf@ = filter to apply
396 * Returns: Nonzero if the key slightly matched the filter.
398 * Use: Updates the hash context with the key contents.
401 extern int key_fingerprint(key */
*k*/
, ghash */
*h*/
,
402 const key_filter */
*kf*/
);
404 /*----- Setting and reading attributes ------------------------------------*/
406 /* --- @key_chkident@ --- *
408 * Arguments: @const char *p@ = pointer to a type string
410 * Returns: Zero if OK, -1 on error.
412 * Use: Checks whether an identification component string is OK.
415 extern int key_chkident(const char */
*p*/
);
417 /* --- @key_chkcomment@ --- *
419 * Arguments: @const char *p@ = pointer to a comment string
421 * Returns: Zero if OK, -1 on error.
423 * Use: Checks whether a comment string is OK.
426 extern int key_chkcomment(const char */
*p*/
);
428 /* --- @key_setcomment@ --- *
430 * Arguments: @key_file *f@ = pointer to key file block
431 * @key *k@ = pointer to key block
432 * @const char *c@ = pointer to comment to set, or zero
434 * Returns: Error code (one of the @KERR@ constants).
436 * Use: Replaces the key's current comment with a new one.
439 extern int key_setcomment(key_file */
*f*/
, key */
*k*/
, const char */
*c*/
);
441 /* --- @key_settag@ --- *
443 * Arguments: @key_file *f@ = pointer to key file block
444 * @key *k@ = pointer to key block
445 * @const char *tag@ = pointer to comment to set, or zero
447 * Returns: Error code (one of the @KERR@ constants).
449 * Use: Replaces the key's current tag with a new one.
452 extern int key_settag(key_file */
*f*/
, key */
*k*/
, const char */
*tag*/
);
454 /* --- @key_fulltag@ --- *
456 * Arguments: @key *k@ = pointer to key
457 * @dstr *d@ = pointer to destination string
461 * Use: Emits the key's full tag, which has the form
462 * `ID:TYPE[:TAG]'. This is used in the textual file format,
463 * and to identify passphrases for locked keys.
466 extern void key_fulltag(key */
*k*/
, dstr */
*d*/
);
468 /* --- @key_qtag@ --- *
470 * Arguments: @key_file *f@ = key file to find a key from
471 * @const char *tag@ = pointer to tag string
472 * @dstr *d@ = pointer to string for full tag name
473 * @key **k@ = where to store the key pointer
474 * @key_data **kd@ = where to store the key data pointer
476 * Returns: Zero if OK, nonzero if it failed.
478 * Use: Performs a full lookup on a qualified tag name. The tag is
479 * qualified by the names of subkeys, separated by dots. Hence,
480 * a qualified tag is ID|TAG[.TAG...]. The various result
481 * pointers can be null to indicate that the result isn't
485 extern int key_qtag(key_file */
*f*/
, const char */
*tag*/
,
486 dstr */
*d*/
, key
**/
*k*/
, key_data
**/
*kd*/
);
488 /* --- @key_getattr@ --- *
490 * Arguments: @key_file *f@ = pointer to file
491 * @key *k@ = pointer to key
492 * @const char *n@ = pointer to attribute name
494 * Returns: Pointer to attribute value, or null if not found.
496 * Use: Returns the value of a key attribute.
499 extern const char *key_getattr(key_file */
*f*/
, key */
*k*/
,
502 /* --- @key_putattr@ --- *
504 * Arguments: @key_file *f@ = pointer to file
505 * @key *k@ = pointer to key
506 * @const char *n@ = pointer to attribute name
507 * @const char *v@ = pointer to attribute value or null
509 * Returns: Error code (one of the @KERR@ constants).
511 * Use: Inserts an attribute on a key. If an attribute with the same
512 * name already exists, it is deleted. Setting a null value
513 * removes the attribute.
516 extern int key_putattr(key_file */
*f*/
, key */
*k*/
,
517 const char */
*n*/
, const char */
*v*/
);
519 /* --- @key_mkattriter@ --- *
521 * Arguments: @key_attriter *i@ = pointer to attribute iterator
522 * @key *k@ = pointer to key
526 * Use: Initializes an attribute iterator. The attributes are
527 * returned by @key_nextattr@.
530 extern void key_mkattriter(key_attriter */
*i*/
, key */
*k*/
);
532 /* --- @key_nextattr@ --- *
534 * Arguments: @key_attriter *i@ = pointer to attribute iterator
535 * @const char **n, **v@ = pointers to name and value
537 * Returns: Zero if no attribute available, or nonzero if returned OK.
539 * Use: Returns the next attribute.
542 extern int key_nextattr(key_attriter */
*i*/
,
543 const char **/
*n*/
, const char **/
*v*/
);
545 /*----- Searching and iterating -------------------------------------------*/
547 /* --- @key_bytype@ --- *
549 * Arguments: @key_file *f@ = key file we want a key from
550 * @const char *type@ = type string for desired key
552 * Returns: Pointer to the best key to use, or null.
554 * Use: Looks up a key by its type. Returns the key with the latest
555 * expiry time. This function will not return an expired key.
558 extern key
*key_bytype(key_file */
*f*/
, const char */
*type*/
);
560 /* --- @key_byid@ --- *
562 * Arguments: @key_file *f@ = key file to find a key from
563 * @uint32 id@ = id to look for
565 * Returns: Key with matching id.
567 * Use: Returns a key given its id. This function will return an
568 * expired key, but not a deleted one.
571 extern key
*key_byid(key_file */
*f*/
, uint32
/*id*/);
573 /* --- @key_bytag@ --- *
575 * Arguments: @key_file *f@ = key file to find a key from
576 * @const char *tag@ = pointer to tag string
578 * Returns: Key with matching id or tag.
580 * Use: Returns a key given its tag or id. This function will return
581 * an expired key, but not a deleted one.
584 extern key
*key_bytag(key_file */
*f*/
, const char */
*tag*/
);
586 /* --- @key_mkiter@ --- *
588 * Arguments: @key_iter *i@ = pointer to iterator object
589 * @key_file *f@ = pointer to file structure
593 * Use: Initializes a key iterator. The keys are returned by
597 extern void key_mkiter(key_iter */
*i*/
, key_file */
*f*/
);
599 /* --- @key_next@ --- *
601 * Arguments: @key_iter *i@ = pointer to iterator object
603 * Returns: Pointer to next key, or null.
605 * Use: Returns the next key in some arbitrary sequence.
608 extern key
*key_next(key_iter */
*i*/
);
610 /*----- Fetching key data conveniently ------------------------------------*/
612 /* --- @key_fetchinit@ --- *
614 * Arguments: @const key_fetchdef *kf@ = pointer to base definition
615 * @key_packstruct *kps@ = pointer to destination packing def
616 * @void *p@ = pointer to destination block
618 * Returns: Pointer to packing definition.
620 * Use: Initializes a packing definition (@key_packdef@ structure).
621 * If @kps@ is null on entry, an appropriately sized block is
622 * allocated automatically. Otherwise it must be large enough.
625 extern key_packdef
*key_fetchinit(const key_fetchdef */
*kf*/
,
626 key_packstruct */
*kp*/
, void */
*p*/
);
628 /* --- @key_fetch@ --- *
630 * Arguments: @key_packdef *kp@ = pointer to packing structure
631 * @key *k@ = key file containing desired key
633 * Returns: Error code, or zero.
635 * Use: Fetches an unpacked key from a packed one.
638 extern int key_fetch(key_packdef */
*kp*/
, key */
*k*/
);
640 /* --- @key_fetchbyname@ --- *
642 * Arguments: @key_packdef *kp@ = pointer to packing structure
643 * @key_file *kf@ = key file containing desired key
644 * @const char *tag@ = user's tag describing the key
646 * Returns: Error code, or zero.
648 * Use: Fetches a named key from a key file and unpacks it
652 extern int key_fetchbyname(key_packdef */
*kp*/
,
653 key_file */
*kf*/
, const char */
*tag*/
);
655 /* --- @key_fetchdone@ --- *
657 * Arguments: @key_packdef *kp@ = pointer to packing structure
661 * Use: Frees a packing structure. If the structure was allocated by
662 * @key_fetchinit@ then it is freed.
665 extern void key_fetchdone(key_packdef */
*kp*/
);
667 /*----- Other functions ---------------------------------------------------*/
669 /* --- @key_moan@ --- *
671 * Arguments: @const char *file@ = name of the file
672 * @int line@ = line number in file
673 * @const char *msg@ = error message
674 * @void *p@ = argument pointer
678 * Use: Reports an error message about loading a key file.
681 extern void key_moan(const char */
*file*/
, int /*line*/,
682 const char */
*msg*/
, void */
*p*/
);
684 /*----- That's all, folks -------------------------------------------------*/