3 * $Id: key.h,v 1.9 2001/06/22 19:37:59 mdw Exp $
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 /*----- Revision history --------------------------------------------------*
33 * Revision 1.9 2001/06/22 19:37:59 mdw
34 * New interface to enquire whether a key has expired.
36 * Revision 1.8 2001/02/03 11:57:38 mdw
37 * Allow creating keyfiles with no file attached.
39 * Revision 1.7 2000/12/06 20:33:27 mdw
40 * Make flags be macros rather than enumerations, to ensure that they're
43 * Revision 1.6 2000/06/17 11:27:43 mdw
44 * Add key fetching interface.
46 * Revision 1.5 2000/02/12 18:55:40 mdw
47 * Make it all compile properly.
49 * Revision 1.4 2000/02/12 18:21:02 mdw
50 * Overhaul of key management (again).
52 * Revision 1.3 1999/12/22 15:47:48 mdw
53 * Major key-management revision.
55 * Revision 1.2 1999/12/10 23:29:48 mdw
56 * Change header file guard names.
58 * Revision 1.1 1999/09/03 08:41:12 mdw
63 #ifndef CATACOMB_KEY_H
64 #define CATACOMB_KEY_H
70 /*----- Header files ------------------------------------------------------*/
75 #include <mLib/bits.h>
76 #include <mLib/dstr.h>
77 #include <mLib/hash.h>
80 #ifndef CATACOMB_KEY_DATA_H
81 # include "key-data.h"
88 /*----- Data structures ---------------------------------------------------*/
90 /* --- Key attributes --- *
92 * Each attribute is stored as a symbol in a symbol table. The value is
93 * the plain (not url-encoded) text to be written to the the file. If the
94 * value is binary data, then by this point it's base-64 encoded.
97 typedef struct key_attr
{
98 sym_base _b
; /* Symbol table data */
99 char *p
; /* Pointer to attribute value */
102 /* --- Main key structure --- *
104 * Each key is stored in two symbol tables, one indexed by keyid, and the
105 * other indexed by type. Because many keys can have the same type, the type
106 * table contains a list of keys, sorted in descending order of expiry.
111 /* --- Hashtable management --- */
113 hash_base _b
; /* Symbol table data */
114 struct key
*next
; /* Next key of the same type */
116 /* --- Basic key attributes --- */
118 uint32 id
; /* Key id used to name it */
119 char *tag
; /* Textual tag name */
120 char *type
; /* Textual key type */
121 time_t exp
, del
; /* Expiry times for keys */
123 /* --- The key data itself --- */
125 key_data k
; /* The actual key data */
127 /* --- Other attributes and commentary --- */
129 sym_table a
; /* Hashtable of key attributes */
130 char *c
; /* Any additional comments */
133 /* --- The keys-by-type entries --- */
135 typedef struct key_ref
{
136 sym_base _b
; /* Symbol table data */
137 key
*k
; /* Pointer to first key in list */
140 /* --- A key file --- */
142 typedef struct key_file
{
143 FILE *fp
; /* File pointer open on file */
144 char *name
; /* Filename used to create it */
145 unsigned f
; /* Various useful flags */
146 hash_table byid
; /* Table of keys by keyid */
147 sym_table bytype
; /* Table of keys by type */
148 sym_table bytag
; /* Table of keys by tag */
149 size_t idload
; /* Loading on id table */
152 /* --- Key file flags --- */
154 #define KF_WRITE 1u /* File opened for writing */
155 #define KF_MODIFIED 2u /* File has been modified */
157 /* --- Iterating over keys --- *
159 * Both of these are simple symbol table iterators, but they're made distinct
160 * types for the dubious benefits that type safety brings.
163 typedef struct { hash_iter i
; time_t t
; } key_iter
;
164 typedef struct { sym_iter i
; } key_attriter
;
166 /* --- Key fetching --- */
168 typedef struct key_fetchdef
{
169 char *name
; /* Name of item */
170 size_t off
; /* Offset into target structure */
171 unsigned e
; /* Flags for the item */
172 const struct key_fetchdef
*kf
; /* Substructure pointer */
175 /* --- File opening options --- */
177 #define KOPEN_READ 0u
178 #define KOPEN_WRITE 1u
179 #define KOPEN_MASK 0xff
180 #define KOPEN_NOFILE 0x100
182 /* --- Various other magic numbers --- */
184 #define KEXP_FOREVER ((time_t)-1) /* Never expire this key */
185 #define KEXP_EXPIRE ((time_t)-2) /* Expire this key when unused */
187 /* --- Key error codes --- */
190 KERR_OK
= 0, /* No error */
191 KERR_BADTAG
= -1, /* Malformed tag string */
192 KERR_BADTYPE
= -2, /* Malformed type string */
193 KERR_BADCOMMENT
= -3, /* Malformed comment string */
194 KERR_DUPID
= -4, /* Duplicate keyid */
195 KERR_DUPTAG
= -5, /* Duplicate key tag string */
196 KERR_READONLY
= -6, /* Key file is read-only */
197 KERR_WILLEXPIRE
= -7, /* Key will eventually expire */
198 KERR_EXPIRED
= -8, /* Key has already expired */
199 KERR_BADFLAGS
= -9, /* Error in flags string */
200 KERR_BADPASS
= -10, /* Error decrypting locked key */
201 KERR_WRONGTYPE
= -11, /* Key has incorrect type */
202 KERR_NOTFOUND
= -12, /* Key couldn't be found */
203 KERR_MAX
/* Largest possible error */
206 /* --- Write error codes --- */
209 KWRITE_OK
, /* Everything went fine */
210 KWRITE_FAIL
= -1, /* Close attempt failed */
211 KWRITE_BROKEN
= -2 /* Key ring needs manual fixing */
214 /* --- Error reporting functions for @key_merge@ and @key_open@ --- */
216 typedef void key_reporter(const char */
*file*/
, int /*line*/,
217 const char */
*err*/
, void */
*p*/
);
219 /* --- Macros for testing expiry --- */
221 #define KEY_EXPIRED(now, exp) \
222 ((exp) == KEXP_EXPIRE || ((exp) != KEXP_FOREVER && (exp) < (now)))
224 /*----- Reading and writing keys and files --------------------------------*/
226 /* --- @key_merge@ --- *
228 * Arguments: @key_file *f@ = pointer to file structure
229 * @const char *file@ = name of file (for error messages)
230 * @FILE *fp@ = file handle to read from
231 * @key_reporter *rep@ = error reporting function
232 * @void *arg@ = argument for function
234 * Returns: Error code (one of the @KERR@ constants).
236 * Use: Reads keys from a file, and inserts them into the file.
239 extern int key_merge(key_file */
*f*/
, const char */
*file*/
, FILE */
*fp*/
,
240 key_reporter */
*rep*/
, void */
*arg*/
);
242 /* --- @key_extract@ --- *
244 * Arguments: @key_file *f@ = pointer to file structure
245 * @key *k@ = key to extract
246 * @FILE *fp@ = file to write on
247 * @const key_filter *kf@ = pointer to key selection block
249 * Returns: Zero if OK, EOF on error.
251 * Use: Extracts a key to an ouptut file.
254 extern int key_extract(key_file */
*f*/
, key */
*k*/
, FILE */
*fp*/
,
255 const key_filter */
*kf*/
);
257 /* --- @key_open@ --- *
259 * Arguments: @key_file *f@ = pointer to file structure to initialize
260 * @const char *file@ = pointer to the file name
261 * @unsigned how@ = opening options (@KOPEN_*@).
262 * @key_reporter *rep@ = error reporting function
263 * @void *arg@ = argument for function
265 * Returns: Zero if it worked, nonzero otherwise.
267 * Use: Opens a key file, reads its contents, and stores them in a
268 * structure. The file is locked appropriately until closed
269 * using @key_close@. On an error, everything is cleared away
270 * tidily. If the file is opened with @KOPEN_WRITE@, it's
271 * created if necessary, with read and write permissions for its
275 extern int key_open(key_file */
*f*/
, const char */
*file*/
, unsigned /*how*/,
276 key_reporter */
*rep*/
, void */
*arg*/
);
278 /* --- @key_close@ --- *
280 * Arguments: @key_file *f@ = pointer to key file block
282 * Returns: A @KWRITE_@ code indicating how it went.
284 * Use: Frees all the key data, writes any changes. Make sure that
285 * all hell breaks loose if this returns @KWRITE_BROKEN@.
288 extern int key_close(key_file */
*f*/
);
290 /* --- @key_save@ --- *
292 * Arguments: @key_file *f@ = pointer to key file block
294 * Returns: A @KWRITE_@ code indicating how well it worked.
296 * Use: Writes a key file's data back to the actual file. This code
297 * is extremely careful about error handling. It should usually
298 * be able to back out somewhere sensible, but it can tell when
299 * it's got itself into a real pickle and starts leaving well
302 * Callers, please make sure that you ring alarm bells when this
303 * function returns @KWRITE_BROKEN@.
306 extern int key_save(key_file */
*f*/
);
308 /* --- @key_lockfile@ --- *
310 * Arguments: @key_file *f@ = pointer to file structure to initialize
311 * @const char *file@ = pointer to the file name
312 * @unsigned how@ = opening options (@KOPEN_*@).
314 * Returns: Zero if it worked, nonzero otherwise.
316 * Use: Opens a keyfile and stores the information needed for
317 * continued access in the structure.
319 * If the file is opened with @KOPEN_WRITE@, it's created if
320 * necessary with read and write permissions for owner only, and
321 * locked for update while it's open.
323 * This is a system-dependent routine, and only really intended
324 * for the private use of @key_open@.
327 extern int key_lockfile(key_file */
*f*/
, const char */
*file*/
,
330 /*----- Creating and manipulating keys ------------------------------------*/
334 * Arguments: @key_file *f@ = pointer to key file
335 * @uint32 id@ = keyid to set
336 * @const char *type@ = the type of this key
337 * @time_t exp@ = when the key expires
338 * @int *err@ = where to store the error condition
340 * Returns: Key block containing new data, or null if it couldn't be
343 * Use: Attaches a new key to a key file. You must have a writable
344 * key file for this to work.
346 * The type is a key type string. This interface doesn't care
347 * about how type strings are formatted: it just treats them as
348 * opaque gobs of text. Clients are advised to choose some
349 * standard for representing key types, though.
351 * The expiry time should either be a time in the future, or the
352 * magic value @KEXP_FOREVER@ which means `never expire this
353 * key'. Be careful with `forever' keys. If I were you, I'd
354 * use a more sophisticated key management system than this for
357 * You have to set the actual key yourself.
360 extern key
*key_new(key_file */
*f*/
, uint32
/*id*/, const char */
*type*/
,
361 time_t /*exp*/, int */
*err*/
);
363 /* --- @key_delete@ --- *
365 * Arguments: @key_file *f@ = pointer to file block
366 * @key *k@ = key to delete
368 * Returns: Error code (one of the @KERR@ constants).
370 * Use: Removes the given key from the list. The key file must be
371 * writable. (Due to the horridness of the data structures,
372 * deleted keys aren't actually removed, just marked so that
373 * they can't be looked up or iterated over. One upshot of
374 * this is that they don't get written back to the file when
378 extern int key_delete(key_file */
*f*/
, key */
*k*/
);
380 /* --- @key_expired@ --- *
382 * Arguments: @key *k@ = pointer to key block
384 * Returns: Zero if the key is OK, nonzero if it's expired.
387 int key_expired(key */
*k*/
);
389 /* --- @key_expire@ --- *
391 * Arguments: @key_file *f@ = pointer to file block
392 * @key *k@ = pointer to key block
394 * Returns: Error code (one of the @KERR@ constants).
396 * Use: Immediately marks the key as expired. It may be removed
397 * immediately, if it is no longer required, and will be removed
398 * by a tidy operation when it is no longer required. The key
399 * file must be writable.
402 extern int key_expire(key_file */
*f*/
, key */
*k*/
);
404 /* --- @key_used@ --- *
406 * Arguments: @key_file *f@ = pointer to key file
407 * @key *k@ = pointer to key block
408 * @time_t t@ = when key can be removed
410 * Returns: Zero if OK, nonzero on failure.
412 * Use: Marks a key as being required until a given time. Even
413 * though the key may expire before then (and won't be returned
414 * by type after that time), it will still be available when
415 * requested explicitly by id. The key file must be writable.
417 * The only (current) reason for failure is attempting to use
418 * a key which can expire for something which can't.
421 extern int key_used(key_file */
*f*/
, key */
*k*/
, time_t /*t*/);
423 /*----- Setting and reading attributes ------------------------------------*/
425 /* --- @key_chkident@ --- *
427 * Arguments: @const char *p@ = pointer to a type string
429 * Returns: Zero if OK, -1 on error.
431 * Use: Checks whether an identification component string is OK.
434 extern int key_chkident(const char */
*p*/
);
436 /* --- @key_chkcomment@ --- *
438 * Arguments: @const char *p@ = pointer to a comment string
440 * Returns: Zero if OK, -1 on error.
442 * Use: Checks whether a comment string is OK.
445 extern int key_chkcomment(const char */
*p*/
);
447 /* --- @key_setcomment@ --- *
449 * Arguments: @key_file *f@ = pointer to key file block
450 * @key *k@ = pointer to key block
451 * @const char *c@ = pointer to comment to set, or zero
453 * Returns: Error code (one of the @KERR@ constants).
455 * Use: Replaces the key's current comment with a new one.
458 extern int key_setcomment(key_file */
*f*/
, key */
*k*/
, const char */
*c*/
);
460 /* --- @key_settag@ --- *
462 * Arguments: @key_file *f@ = pointer to key file block
463 * @key *k@ = pointer to key block
464 * @const char *tag@ = pointer to comment to set, or zero
466 * Returns: Error code (one of the @KERR@ constants).
468 * Use: Replaces the key's current tag with a new one.
471 extern int key_settag(key_file */
*f*/
, key */
*k*/
, const char */
*tag*/
);
473 /* --- @key_fulltag@ --- *
475 * Arguments: @key *k@ = pointer to key
476 * @dstr *d@ = pointer to destination string
480 * Use: Emits the key's full tag, which has the form
481 * `ID:TYPE[:TAG]'. This is used in the textual file format,
482 * and to identify passphrases for locked keys.
485 extern void key_fulltag(key */
*k*/
, dstr */
*d*/
);
487 /* --- @key_qtag@ --- *
489 * Arguments: @key_file *f@ = key file to find a key from
490 * @const char *tag@ = pointer to tag string
491 * @dstr *d@ = pointer to string for full tag name
492 * @key **k@ = where to store the key pointer
493 * @key_data **kd@ = where to store the key data pointer
495 * Returns: Zero if OK, nonzero if it failed.
497 * Use: Performs a full lookup on a qualified tag name. The tag is
498 * qualified by the names of subkeys, separated by dots. Hence,
499 * a qualified tag is ID|TAG[.TAG...]. The various result
500 * pointers can be null to indicate that the result isn't
504 extern int key_qtag(key_file */
*f*/
, const char */
*tag*/
,
505 dstr */
*d*/
, key
**/
*k*/
, key_data
**/
*kd*/
);
507 /* --- @key_getattr@ --- *
509 * Arguments: @key_file *f@ = pointer to file
510 * @key *k@ = pointer to key
511 * @const char *n@ = pointer to attribute name
513 * Returns: Pointer to attribute value, or null if not found.
515 * Use: Returns the value of a key attribute.
518 extern const char *key_getattr(key_file */
*f*/
, key */
*k*/
,
521 /* --- @key_putattr@ --- *
523 * Arguments: @key_file *f@ = pointer to file
524 * @key *k@ = pointer to key
525 * @const char *n@ = pointer to attribute name
526 * @const char *v@ = pointer to attribute value or null
528 * Returns: Error code (one of the @KERR@ constants).
530 * Use: Inserts an attribute on a key. If an attribute with the same
531 * name already exists, it is deleted. Setting a null value
532 * removes the attribute.
535 extern int key_putattr(key_file */
*f*/
, key */
*k*/
,
536 const char */
*n*/
, const char */
*v*/
);
538 /* --- @key_mkattriter@ --- *
540 * Arguments: @key_attriter *i@ = pointer to attribute iterator
541 * @key *k@ = pointer to key
545 * Use: Initializes an attribute iterator. The attributes are
546 * returned by @key_nextattr@.
549 extern void key_mkattriter(key_attriter */
*i*/
, key */
*k*/
);
551 /* --- @key_nextattr@ --- *
553 * Arguments: @key_attriter *i@ = pointer to attribute iterator
554 * @const char **n, **v@ = pointers to name and value
556 * Returns: Zero if no attribute available, or nonzero if returned OK.
558 * Use: Returns the next attribute.
561 extern int key_nextattr(key_attriter */
*i*/
,
562 const char **/
*n*/
, const char **/
*v*/
);
564 /*----- Searching and iterating -------------------------------------------*/
566 /* --- @key_bytype@ --- *
568 * Arguments: @key_file *f@ = key file we want a key from
569 * @const char *type@ = type string for desired key
571 * Returns: Pointer to the best key to use, or null.
573 * Use: Looks up a key by its type. Returns the key with the latest
574 * expiry time. This function will not return an expired key.
577 extern key
*key_bytype(key_file */
*f*/
, const char */
*type*/
);
579 /* --- @key_byid@ --- *
581 * Arguments: @key_file *f@ = key file to find a key from
582 * @uint32 id@ = id to look for
584 * Returns: Key with matching id.
586 * Use: Returns a key given its id. This function will return an
587 * expired key, but not a deleted one.
590 extern key
*key_byid(key_file */
*f*/
, uint32
/*id*/);
592 /* --- @key_bytag@ --- *
594 * Arguments: @key_file *f@ = key file to find a key from
595 * @const char *tag@ = pointer to tag string
597 * Returns: Key with matching id or tag.
599 * Use: Returns a key given its tag or id. This function will return
600 * an expired key, but not a deleted one.
603 extern key
*key_bytag(key_file */
*f*/
, const char */
*tag*/
);
605 /* --- @key_mkiter@ --- *
607 * Arguments: @key_iter *i@ = pointer to iterator object
608 * @key_file *f@ = pointer to file structure
612 * Use: Initializes a key iterator. The keys are returned by
616 extern void key_mkiter(key_iter */
*i*/
, key_file */
*f*/
);
618 /* --- @key_next@ --- *
620 * Arguments: @key_iter *i@ = pointer to iterator object
622 * Returns: Pointer to next key, or null.
624 * Use: Returns the next key in some arbitrary sequence.
627 extern key
*key_next(key_iter */
*i*/
);
629 /*----- Fetching key data conveniently ------------------------------------*/
631 /* --- @key_fetchinit@ --- *
633 * Arguments: @const key_fetchdef *kf@ = pointer to base definition
634 * @key_packstruct *kps@ = pointer to destination packing def
635 * @void *p@ = pointer to destination block
637 * Returns: Pointer to packing definition.
639 * Use: Initializes a packing definition (@key_packdef@ structure).
640 * If @kps@ is null on entry, an appropriately sized block is
641 * allocated automatically. Otherwise it must be large enough.
644 extern key_packdef
*key_fetchinit(const key_fetchdef */
*kf*/
,
645 key_packstruct */
*kp*/
, void */
*p*/
);
647 /* --- @key_fetch@ --- *
649 * Arguments: @key_packdef *kp@ = pointer to packing structure
650 * @key *k@ = key file containing desired key
652 * Returns: Error code, or zero.
654 * Use: Fetches an unpacked key from a packed one.
657 extern int key_fetch(key_packdef */
*kp*/
, key */
*k*/
);
659 /* --- @key_fetchbyname@ --- *
661 * Arguments: @key_packdef *kp@ = pointer to packing structure
662 * @key_file *kf@ = key file containing desired key
663 * @const char *tag@ = user's tag describing the key
665 * Returns: Error code, or zero.
667 * Use: Fetches a named key from a key file and unpacks it
671 extern int key_fetchbyname(key_packdef */
*kp*/
,
672 key_file */
*kf*/
, const char */
*tag*/
);
674 /* --- @key_fetchdone@ --- *
676 * Arguments: @key_packdef *kp@ = pointer to packing structure
680 * Use: Frees a packing structure. If the structure was allocated by
681 * @key_fetchinit@ then it is freed.
684 extern void key_fetchdone(key_packdef */
*kp*/
);
686 /*----- Other functions ---------------------------------------------------*/
688 /* --- @key_moan@ --- *
690 * Arguments: @const char *file@ = name of the file
691 * @int line@ = line number in file
692 * @const char *msg@ = error message
693 * @void *p@ = argument pointer
697 * Use: Reports an error message about loading a key file.
700 extern void key_moan(const char */
*file*/
, int /*line*/,
701 const char */
*msg*/
, void */
*p*/
);
703 /* --- @key_strerror@ --- *
705 * Arguments: @int err@ = error code from @key_new@
707 * Returns: Pointer to error string.
709 * Use: Translates a @KERR@ error code into a human-readable string.
712 extern const char *key_strerror(int /*err*/);
714 /*----- That's all, folks -------------------------------------------------*/