3 * $Id: key.h,v 1.7 2000/12/06 20:33:27 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 1.7 2000/12/06 20:33:27 mdw
34 * Make flags be macros rather than enumerations, to ensure that they're
37 * Revision 1.6 2000/06/17 11:27:43 mdw
38 * Add key fetching interface.
40 * Revision 1.5 2000/02/12 18:55:40 mdw
41 * Make it all compile properly.
43 * Revision 1.4 2000/02/12 18:21:02 mdw
44 * Overhaul of key management (again).
46 * Revision 1.3 1999/12/22 15:47:48 mdw
47 * Major key-management revision.
49 * Revision 1.2 1999/12/10 23:29:48 mdw
50 * Change header file guard names.
52 * Revision 1.1 1999/09/03 08:41:12 mdw
57 #ifndef CATACOMB_KEY_H
58 #define CATACOMB_KEY_H
64 /*----- Header files ------------------------------------------------------*/
69 #include <mLib/bits.h>
70 #include <mLib/dstr.h>
71 #include <mLib/hash.h>
74 #ifndef CATACOMB_KEY_DATA_H
75 # include "key-data.h"
82 /*----- Data structures ---------------------------------------------------*/
84 /* --- Key attributes --- *
86 * Each attribute is stored as a symbol in a symbol table. The value is
87 * the plain (not url-encoded) text to be written to the the file. If the
88 * value is binary data, then by this point it's base-64 encoded.
91 typedef struct key_attr
{
92 sym_base _b
; /* Symbol table data */
93 char *p
; /* Pointer to attribute value */
96 /* --- Main key structure --- *
98 * Each key is stored in two symbol tables, one indexed by keyid, and the
99 * other indexed by type. Because many keys can have the same type, the type
100 * table contains a list of keys, sorted in descending order of expiry.
105 /* --- Hashtable management --- */
107 hash_base _b
; /* Symbol table data */
108 struct key
*next
; /* Next key of the same type */
110 /* --- Basic key attributes --- */
112 uint32 id
; /* Key id used to name it */
113 char *tag
; /* Textual tag name */
114 char *type
; /* Textual key type */
115 time_t exp
, del
; /* Expiry times for keys */
117 /* --- The key data itself --- */
119 key_data k
; /* The actual key data */
121 /* --- Other attributes and commentary --- */
123 sym_table a
; /* Hashtable of key attributes */
124 char *c
; /* Any additional comments */
127 /* --- The keys-by-type entries --- */
129 typedef struct key_ref
{
130 sym_base _b
; /* Symbol table data */
131 key
*k
; /* Pointer to first key in list */
134 /* --- A key file --- */
136 typedef struct key_file
{
137 FILE *fp
; /* File pointer open on file */
138 char *name
; /* Filename used to create it */
139 unsigned f
; /* Various useful flags */
140 hash_table byid
; /* Table of keys by keyid */
141 sym_table bytype
; /* Table of keys by type */
142 sym_table bytag
; /* Table of keys by tag */
143 size_t idload
; /* Loading on id table */
146 /* --- Key file flags --- */
148 #define KF_WRITE 1u /* File opened for writing */
149 #define KF_MODIFIED 2u /* File has been modified */
151 /* --- Iterating over keys --- *
153 * Both of these are simple symbol table iterators, but they're made distinct
154 * types for the dubious benefits that type safety brings.
157 typedef struct { hash_iter i
; time_t t
; } key_iter
;
158 typedef struct { sym_iter i
; } key_attriter
;
160 /* --- Key fetching --- */
162 typedef struct key_fetchdef
{
163 char *name
; /* Name of item */
164 size_t off
; /* Offset into target structure */
165 unsigned e
; /* Flags for the item */
166 const struct key_fetchdef
*kf
; /* Substructure pointer */
169 /* --- File opening options --- */
176 /* --- Various other magic numbers --- */
178 #define KEXP_FOREVER ((time_t)-1) /* Never expire this key */
179 #define KEXP_EXPIRE ((time_t)-2) /* Expire this key when unused */
181 /* --- Key error codes --- */
184 KERR_OK
= 0, /* No error */
185 KERR_BADTAG
= -1, /* Malformed tag string */
186 KERR_BADTYPE
= -2, /* Malformed type string */
187 KERR_BADCOMMENT
= -3, /* Malformed comment string */
188 KERR_DUPID
= -4, /* Duplicate keyid */
189 KERR_DUPTAG
= -5, /* Duplicate key tag string */
190 KERR_READONLY
= -6, /* Key file is read-only */
191 KERR_WILLEXPIRE
= -7, /* Key will eventually expire */
192 KERR_EXPIRED
= -8, /* Key has already expired */
193 KERR_BADFLAGS
= -9, /* Error in flags string */
194 KERR_BADPASS
= -10, /* Error decrypting locked key */
195 KERR_WRONGTYPE
= -11, /* Key has incorrect type */
196 KERR_NOTFOUND
= -12, /* Key couldn't be found */
197 KERR_MAX
/* Largest possible error */
200 /* --- Write error codes --- */
203 KWRITE_OK
, /* Everything went fine */
204 KWRITE_FAIL
= -1, /* Close attempt failed */
205 KWRITE_BROKEN
= -2 /* Key ring needs manual fixing */
208 /* --- Error reporting functions for @key_merge@ and @key_open@ --- */
210 typedef void key_reporter(const char */
*file*/
, int /*line*/,
211 const char */
*err*/
, void */
*p*/
);
213 /* --- Macros for testing expiry --- */
215 #define KEY_EXPIRED(now, exp) \
216 ((exp) == KEXP_EXPIRE || ((exp) != KEXP_FOREVER && (exp) < (now)))
218 /*----- Reading and writing keys and files --------------------------------*/
220 /* --- @key_merge@ --- *
222 * Arguments: @key_file *f@ = pointer to file structure
223 * @const char *file@ = name of file (for error messages)
224 * @FILE *fp@ = file handle to read from
225 * @key_reporter *rep@ = error reporting function
226 * @void *arg@ = argument for function
228 * Returns: Error code (one of the @KERR@ constants).
230 * Use: Reads keys from a file, and inserts them into the file.
233 extern int key_merge(key_file */
*f*/
, const char */
*file*/
, FILE */
*fp*/
,
234 key_reporter */
*rep*/
, void */
*arg*/
);
236 /* --- @key_extract@ --- *
238 * Arguments: @key_file *f@ = pointer to file structure
239 * @key *k@ = key to extract
240 * @FILE *fp@ = file to write on
241 * @const key_filter *kf@ = pointer to key selection block
243 * Returns: Zero if OK, EOF on error.
245 * Use: Extracts a key to an ouptut file.
248 extern int key_extract(key_file */
*f*/
, key */
*k*/
, FILE */
*fp*/
,
249 const key_filter */
*kf*/
);
251 /* --- @key_open@ --- *
253 * Arguments: @key_file *f@ = pointer to file structure to initialize
254 * @const char *file@ = pointer to the file name
255 * @int how@ = opening options (@KOPEN_*@).
256 * @key_reporter *rep@ = error reporting function
257 * @void *arg@ = argument for function
259 * Returns: Zero if it worked, nonzero otherwise.
261 * Use: Opens a key file, reads its contents, and stores them in a
262 * structure. The file is locked appropriately until closed
263 * using @key_close@. On an error, everything is cleared away
264 * tidily. If the file is opened with @KOPEN_WRITE@, it's
265 * created if necessary, with read and write permissions for its
269 extern int key_open(key_file */
*f*/
, const char */
*file*/
, int /*how*/,
270 key_reporter */
*rep*/
, void */
*arg*/
);
272 /* --- @key_close@ --- *
274 * Arguments: @key_file *f@ = pointer to key file block
276 * Returns: A @KWRITE_@ code indicating how it went.
278 * Use: Frees all the key data, writes any changes. Make sure that
279 * all hell breaks loose if this returns @KWRITE_BROKEN@.
282 extern int key_close(key_file */
*f*/
);
284 /* --- @key_save@ --- *
286 * Arguments: @key_file *f@ = pointer to key file block
288 * Returns: A @KWRITE_@ code indicating how well it worked.
290 * Use: Writes a key file's data back to the actual file. This code
291 * is extremely careful about error handling. It should usually
292 * be able to back out somewhere sensible, but it can tell when
293 * it's got itself into a real pickle and starts leaving well
296 * Callers, please make sure that you ring alarm bells when this
297 * function returns @KWRITE_BROKEN@.
300 extern int key_save(key_file */
*f*/
);
302 /* --- @key_lockfile@ --- *
304 * Arguments: @key_file *f@ = pointer to file structure to initialize
305 * @const char *file@ = pointer to the file name
306 * @int how@ = opening options (@KOPEN_*@).
308 * Returns: Zero if it worked, nonzero otherwise.
310 * Use: Opens a keyfile and stores the information needed for
311 * continued access in the structure.
313 * If the file is opened with @KOPEN_WRITE@, it's created if
314 * necessary with read and write permissions for owner only, and
315 * locked for update while it's open.
317 * This is a system-dependent routine, and only really intended
318 * for the private use of @key_open@.
321 extern int key_lockfile(key_file */
*f*/
, const char */
*file*/
, int /*how*/);
323 /*----- Creating and manipulating keys ------------------------------------*/
327 * Arguments: @key_file *f@ = pointer to key file
328 * @uint32 id@ = keyid to set
329 * @const char *type@ = the type of this key
330 * @time_t exp@ = when the key expires
331 * @int *err@ = where to store the error condition
333 * Returns: Key block containing new data, or null if it couldn't be
336 * Use: Attaches a new key to a key file. You must have a writable
337 * key file for this to work.
339 * The type is a key type string. This interface doesn't care
340 * about how type strings are formatted: it just treats them as
341 * opaque gobs of text. Clients are advised to choose some
342 * standard for representing key types, though.
344 * The expiry time should either be a time in the future, or the
345 * magic value @KEXP_FOREVER@ which means `never expire this
346 * key'. Be careful with `forever' keys. If I were you, I'd
347 * use a more sophisticated key management system than this for
350 * You have to set the actual key yourself.
353 extern key
*key_new(key_file */
*f*/
, uint32
/*id*/, const char */
*type*/
,
354 time_t /*exp*/, int */
*err*/
);
356 /* --- @key_delete@ --- *
358 * Arguments: @key_file *f@ = pointer to file block
359 * @key *k@ = key to delete
361 * Returns: Error code (one of the @KERR@ constants).
363 * Use: Removes the given key from the list. The key file must be
364 * writable. (Due to the horridness of the data structures,
365 * deleted keys aren't actually removed, just marked so that
366 * they can't be looked up or iterated over. One upshot of
367 * this is that they don't get written back to the file when
371 extern int key_delete(key_file */
*f*/
, key */
*k*/
);
373 /* --- @key_expire@ --- *
375 * Arguments: @key_file *f@ = pointer to file block
376 * @key *k@ = pointer to key block
378 * Returns: Error code (one of the @KERR@ constants).
380 * Use: Immediately marks the key as expired. It may be removed
381 * immediately, if it is no longer required, and will be removed
382 * by a tidy operation when it is no longer required. The key
383 * file must be writable.
386 extern int key_expire(key_file */
*f*/
, key */
*k*/
);
388 /* --- @key_used@ --- *
390 * Arguments: @key_file *f@ = pointer to key file
391 * @key *k@ = pointer to key block
392 * @time_t t@ = when key can be removed
394 * Returns: Zero if OK, nonzero on failure.
396 * Use: Marks a key as being required until a given time. Even
397 * though the key may expire before then (and won't be returned
398 * by type after that time), it will still be available when
399 * requested explicitly by id. The key file must be writable.
401 * The only (current) reason for failure is attempting to use
402 * a key which can expire for something which can't.
405 extern int key_used(key_file */
*f*/
, key */
*k*/
, time_t /*t*/);
407 /*----- Setting and reading attributes ------------------------------------*/
409 /* --- @key_chkident@ --- *
411 * Arguments: @const char *p@ = pointer to a type string
413 * Returns: Zero if OK, -1 on error.
415 * Use: Checks whether an identification component string is OK.
418 extern int key_chkident(const char */
*p*/
);
420 /* --- @key_chkcomment@ --- *
422 * Arguments: @const char *p@ = pointer to a comment string
424 * Returns: Zero if OK, -1 on error.
426 * Use: Checks whether a comment string is OK.
429 extern int key_chkcomment(const char */
*p*/
);
431 /* --- @key_setcomment@ --- *
433 * Arguments: @key_file *f@ = pointer to key file block
434 * @key *k@ = pointer to key block
435 * @const char *c@ = pointer to comment to set, or zero
437 * Returns: Error code (one of the @KERR@ constants).
439 * Use: Replaces the key's current comment with a new one.
442 extern int key_setcomment(key_file */
*f*/
, key */
*k*/
, const char */
*c*/
);
444 /* --- @key_settag@ --- *
446 * Arguments: @key_file *f@ = pointer to key file block
447 * @key *k@ = pointer to key block
448 * @const char *tag@ = pointer to comment to set, or zero
450 * Returns: Error code (one of the @KERR@ constants).
452 * Use: Replaces the key's current tag with a new one.
455 extern int key_settag(key_file */
*f*/
, key */
*k*/
, const char */
*tag*/
);
457 /* --- @key_fulltag@ --- *
459 * Arguments: @key *k@ = pointer to key
460 * @dstr *d@ = pointer to destination string
464 * Use: Emits the key's full tag, which has the form
465 * `ID:TYPE[:TAG]'. This is used in the textual file format,
466 * and to identify passphrases for locked keys.
469 extern void key_fulltag(key */
*k*/
, dstr */
*d*/
);
471 /* --- @key_qtag@ --- *
473 * Arguments: @key_file *f@ = key file to find a key from
474 * @const char *tag@ = pointer to tag string
475 * @dstr *d@ = pointer to string for full tag name
476 * @key **k@ = where to store the key pointer
477 * @key_data **kd@ = where to store the key data pointer
479 * Returns: Zero if OK, nonzero if it failed.
481 * Use: Performs a full lookup on a qualified tag name. The tag is
482 * qualified by the names of subkeys, separated by dots. Hence,
483 * a qualified tag is ID|TAG[.TAG...]. The various result
484 * pointers can be null to indicate that the result isn't
488 extern int key_qtag(key_file */
*f*/
, const char */
*tag*/
,
489 dstr */
*d*/
, key
**/
*k*/
, key_data
**/
*kd*/
);
491 /* --- @key_getattr@ --- *
493 * Arguments: @key_file *f@ = pointer to file
494 * @key *k@ = pointer to key
495 * @const char *n@ = pointer to attribute name
497 * Returns: Pointer to attribute value, or null if not found.
499 * Use: Returns the value of a key attribute.
502 extern const char *key_getattr(key_file */
*f*/
, key */
*k*/
,
505 /* --- @key_putattr@ --- *
507 * Arguments: @key_file *f@ = pointer to file
508 * @key *k@ = pointer to key
509 * @const char *n@ = pointer to attribute name
510 * @const char *v@ = pointer to attribute value or null
512 * Returns: Error code (one of the @KERR@ constants).
514 * Use: Inserts an attribute on a key. If an attribute with the same
515 * name already exists, it is deleted. Setting a null value
516 * removes the attribute.
519 extern int key_putattr(key_file */
*f*/
, key */
*k*/
,
520 const char */
*n*/
, const char */
*v*/
);
522 /* --- @key_mkattriter@ --- *
524 * Arguments: @key_attriter *i@ = pointer to attribute iterator
525 * @key *k@ = pointer to key
529 * Use: Initializes an attribute iterator. The attributes are
530 * returned by @key_nextattr@.
533 extern void key_mkattriter(key_attriter */
*i*/
, key */
*k*/
);
535 /* --- @key_nextattr@ --- *
537 * Arguments: @key_attriter *i@ = pointer to attribute iterator
538 * @const char **n, **v@ = pointers to name and value
540 * Returns: Zero if no attribute available, or nonzero if returned OK.
542 * Use: Returns the next attribute.
545 extern int key_nextattr(key_attriter */
*i*/
,
546 const char **/
*n*/
, const char **/
*v*/
);
548 /*----- Searching and iterating -------------------------------------------*/
550 /* --- @key_bytype@ --- *
552 * Arguments: @key_file *f@ = key file we want a key from
553 * @const char *type@ = type string for desired key
555 * Returns: Pointer to the best key to use, or null.
557 * Use: Looks up a key by its type. Returns the key with the latest
558 * expiry time. This function will not return an expired key.
561 extern key
*key_bytype(key_file */
*f*/
, const char */
*type*/
);
563 /* --- @key_byid@ --- *
565 * Arguments: @key_file *f@ = key file to find a key from
566 * @uint32 id@ = id to look for
568 * Returns: Key with matching id.
570 * Use: Returns a key given its id. This function will return an
571 * expired key, but not a deleted one.
574 extern key
*key_byid(key_file */
*f*/
, uint32
/*id*/);
576 /* --- @key_bytag@ --- *
578 * Arguments: @key_file *f@ = key file to find a key from
579 * @const char *tag@ = pointer to tag string
581 * Returns: Key with matching id or tag.
583 * Use: Returns a key given its tag or id. This function will return
584 * an expired key, but not a deleted one.
587 extern key
*key_bytag(key_file */
*f*/
, const char */
*tag*/
);
589 /* --- @key_mkiter@ --- *
591 * Arguments: @key_iter *i@ = pointer to iterator object
592 * @key_file *f@ = pointer to file structure
596 * Use: Initializes a key iterator. The keys are returned by
600 extern void key_mkiter(key_iter */
*i*/
, key_file */
*f*/
);
602 /* --- @key_next@ --- *
604 * Arguments: @key_iter *i@ = pointer to iterator object
606 * Returns: Pointer to next key, or null.
608 * Use: Returns the next key in some arbitrary sequence.
611 extern key
*key_next(key_iter */
*i*/
);
613 /*----- Fetching key data conveniently ------------------------------------*/
615 /* --- @key_fetchinit@ --- *
617 * Arguments: @const key_fetchdef *kf@ = pointer to base definition
618 * @key_packstruct *kps@ = pointer to destination packing def
619 * @void *p@ = pointer to destination block
621 * Returns: Pointer to packing definition.
623 * Use: Initializes a packing definition (@key_packdef@ structure).
624 * If @kps@ is null on entry, an appropriately sized block is
625 * allocated automatically. Otherwise it must be large enough.
628 extern key_packdef
*key_fetchinit(const key_fetchdef */
*kf*/
,
629 key_packstruct */
*kp*/
, void */
*p*/
);
631 /* --- @key_fetch@ --- *
633 * Arguments: @key_packdef *kp@ = pointer to packing structure
634 * @key *k@ = key file containing desired key
636 * Returns: Error code, or zero.
638 * Use: Fetches an unpacked key from a packed one.
641 extern int key_fetch(key_packdef */
*kp*/
, key */
*k*/
);
643 /* --- @key_fetchbyname@ --- *
645 * Arguments: @key_packdef *kp@ = pointer to packing structure
646 * @key_file *kf@ = key file containing desired key
647 * @const char *tag@ = user's tag describing the key
649 * Returns: Error code, or zero.
651 * Use: Fetches a named key from a key file and unpacks it
655 extern int key_fetchbyname(key_packdef */
*kp*/
,
656 key_file */
*kf*/
, const char */
*tag*/
);
658 /* --- @key_fetchdone@ --- *
660 * Arguments: @key_packdef *kp@ = pointer to packing structure
664 * Use: Frees a packing structure. If the structure was allocated by
665 * @key_fetchinit@ then it is freed.
668 extern void key_fetchdone(key_packdef */
*kp*/
);
670 /*----- Other functions ---------------------------------------------------*/
672 /* --- @key_moan@ --- *
674 * Arguments: @const char *file@ = name of the file
675 * @int line@ = line number in file
676 * @const char *msg@ = error message
677 * @void *p@ = argument pointer
681 * Use: Reports an error message about loading a key file.
684 extern void key_moan(const char */
*file*/
, int /*line*/,
685 const char */
*msg*/
, void */
*p*/
);
687 /* --- @key_strerror@ --- *
689 * Arguments: @int err@ = error code from @key_new@
691 * Returns: Pointer to error string.
693 * Use: Translates a @KERR@ error code into a human-readable string.
696 extern const char *key_strerror(int /*err*/);
698 /*----- That's all, folks -------------------------------------------------*/