3 * $Id: key.h,v 1.4 2000/02/12 18:21:02 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 1.4 2000/02/12 18:21:02 mdw
34 * Overhaul of key management (again).
36 * Revision 1.3 1999/12/22 15:47:48 mdw
37 * Major key-management revision.
39 * Revision 1.2 1999/12/10 23:29:48 mdw
40 * Change header file guard names.
42 * Revision 1.1 1999/09/03 08:41:12 mdw
47 #ifndef CATACOMB_KEY_H
48 #define CATACOMB_KEY_H
54 /*----- Header files ------------------------------------------------------*/
59 #include <mLib/bits.h>
60 #include <mLib/dstr.h>
61 #include <mLib/hash.h>
64 #ifndef CATACOMB_KEY_DATA_H
65 # include "key-data.h"
72 /*----- Data structures ---------------------------------------------------*/
74 /* --- Key attributes --- *
76 * Each attribute is stored as a symbol in a symbol table. The value is
77 * the plain (not url-encoded) text to be written to the the file. If the
78 * value is binary data, then by this point it's base-64 encoded.
81 typedef struct key_attr
{
82 sym_base _b
; /* Symbol table data */
83 char *p
; /* Pointer to attribute value */
86 /* --- Main key structure --- *
88 * Each key is stored in two symbol tables, one indexed by keyid, and the
89 * other indexed by type. Because many keys can have the same type, the type
90 * table contains a list of keys, sorted in descending order of expiry.
95 /* --- Hashtable management --- */
97 hash_base _b
; /* Symbol table data */
98 struct key
*next
; /* Next key of the same type */
100 /* --- Basic key attributes --- */
102 uint32 id
; /* Key id used to name it */
103 char *tag
; /* Textual tag name */
104 char *type
; /* Textual key type */
105 time_t exp
, del
; /* Expiry times for keys */
107 /* --- The key data itself --- */
109 key_data k
; /* The actual key data */
111 /* --- Other attributes and commentary --- */
113 sym_table a
; /* Hashtable of key attributes */
114 char *c
; /* Any additional comments */
117 /* --- The keys-by-type entries --- */
119 typedef struct key_ref
{
120 sym_base _b
; /* Symbol table data */
121 key
*k
; /* Pointer to first key in list */
124 /* --- A key file --- */
126 typedef struct key_file
{
127 FILE *fp
; /* File pointer open on file */
128 char *name
; /* Filename used to create it */
129 unsigned f
; /* Various useful flags */
130 hash_table byid
; /* Table of keys by keyid */
131 sym_table bytype
; /* Table of keys by type */
132 sym_table bytag
; /* Table of keys by tag */
133 size_t idload
; /* Loading on id table */
136 /* --- Key file flags --- */
139 KF_WRITE
= 1, /* File opened for writing */
140 KF_MODIFIED
= 2 /* File has been modified */
143 /* --- Iterating over keys --- *
145 * Both of these are simple symbol table iterators, but they're made distinct
146 * types for the dubious benefits that type safety brings.
149 typedef struct { hash_iter i
; time_t t
; } key_iter
;
150 typedef struct { sym_iter i
; } key_attriter
;
152 /* --- File opening options --- */
159 /* --- Various other magic numbers --- */
161 #define KEXP_FOREVER ((time_t)-1) /* Never expire this key */
162 #define KEXP_EXPIRE ((time_t)-2) /* Expire this key when unused */
164 /* --- Key error codes --- */
167 KERR_OK
= 0, /* No error */
168 KERR_BADTAG
= -1, /* Malformed tag string */
169 KERR_BADTYPE
= -2, /* Malformed type string */
170 KERR_BADCOMMENT
= -3, /* Malformed comment string */
171 KERR_DUPID
= -4, /* Duplicate keyid */
172 KERR_DUPTAG
= -5, /* Duplicate key tag string */
173 KERR_READONLY
= -6, /* Key file is read-only */
174 KERR_WILLEXPIRE
= -7, /* Key will eventually expire */
175 KERR_EXPIRED
= -8, /* Key has already expired */
176 KERR_BADFLAGS
= -9, /* Error in flags string */
177 KERR_BADPASS
= -10, /* Error decrypting locked key */
178 KERR_BADTYPE
= -11, /* Key has incorrect type */
179 KERR_NOTFOUND
= -12, /* Key couldn't be found */
180 KERR_MAX
/* Largest possible error */
183 /* --- Write error codes --- */
186 KWRITE_OK
, /* Everything went fine */
187 KWRITE_FAIL
= -1, /* Close attempt failed */
188 KWRITE_BROKEN
= -2 /* Key ring needs manual fixing */
191 /* --- Error reporting functions for @key_merge@ and @key_open@ --- */
193 typedef void key_reporter(const char */
*file*/
, int /*line*/,
194 const char */
*err*/
, void */
*p*/
);
196 /* --- Macros for testing expiry --- */
198 #define KEY_EXPIRED(now, exp) \
199 ((exp) == KEXP_EXPIRE || ((exp) != KEXP_FOREVER && (exp) < (now)))
201 /*----- Reading and writing keys and files --------------------------------*/
203 /* --- @key_merge@ --- *
205 * Arguments: @key_file *f@ = pointer to file structure
206 * @const char *file@ = name of file (for error messages)
207 * @FILE *fp@ = file handle to read from
208 * @key_reporter *rep@ = error reporting function
209 * @void *arg@ = argument for function
211 * Returns: Error code (one of the @KERR@ constants).
213 * Use: Reads keys from a file, and inserts them into the file.
216 extern int key_merge(key_file */
*f*/
, const char */
*file*/
, FILE */
*fp*/
,
217 key_reporter */
*rep*/
, void */
*arg*/
);
219 /* --- @key_extract@ --- *
221 * Arguments: @key_file *f@ = pointer to file structure
222 * @key *k@ = key to extract
223 * @FILE *fp@ = file to write on
224 * @const key_filter *kf@ = pointer to key selection block
226 * Returns: Zero if OK, EOF on error.
228 * Use: Extracts a key to an ouptut file.
231 extern int key_extract(key_file */
*f*/
, key */
*k*/
, FILE */
*fp*/
,
232 const key_filter */
*kf*/
);
234 /* --- @key_open@ --- *
236 * Arguments: @key_file *f@ = pointer to file structure to initialize
237 * @const char *file@ = pointer to the file name
238 * @int how@ = opening options (@KOPEN_*@).
239 * @key_reporter *rep@ = error reporting function
240 * @void *arg@ = argument for function
242 * Returns: Zero if it worked, nonzero otherwise.
244 * Use: Opens a key file, reads its contents, and stores them in a
245 * structure. The file is locked appropriately until closed
246 * using @key_close@. On an error, everything is cleared away
247 * tidily. If the file is opened with @KOPEN_WRITE@, it's
248 * created if necessary, with read and write permissions for its
252 extern int key_open(key_file */
*f*/
, const char */
*file*/
, int /*how*/,
253 key_reporter */
*rep*/
, void */
*arg*/
);
255 /* --- @key_close@ --- *
257 * Arguments: @key_file *f@ = pointer to key file block
259 * Returns: A @KWRITE_@ code indicating how it went.
261 * Use: Frees all the key data, writes any changes. Make sure that
262 * all hell breaks loose if this returns @KWRITE_BROKEN@.
265 extern int key_close(key_file */
*f*/
);
267 /* --- @key_save@ --- *
269 * Arguments: @key_file *f@ = pointer to key file block
271 * Returns: A @KWRITE_@ code indicating how well it worked.
273 * Use: Writes a key file's data back to the actual file. This code
274 * is extremely careful about error handling. It should usually
275 * be able to back out somewhere sensible, but it can tell when
276 * it's got itself into a real pickle and starts leaving well
279 * Callers, please make sure that you ring alarm bells when this
280 * function returns @KWRITE_BROKEN@.
283 extern int key_save(key_file */
*f*/
);
285 /* --- @key_lockfile@ --- *
287 * Arguments: @key_file *f@ = pointer to file structure to initialize
288 * @const char *file@ = pointer to the file name
289 * @int how@ = opening options (@KOPEN_*@).
291 * Returns: Zero if it worked, nonzero otherwise.
293 * Use: Opens a keyfile and stores the information needed for
294 * continued access in the structure.
296 * If the file is opened with @KOPEN_WRITE@, it's created if
297 * necessary with read and write permissions for owner only, and
298 * locked for update while it's open.
300 * This is a system-dependent routine, and only really intended
301 * for the private use of @key_open@.
304 extern int key_lockfile(key_file */
*f*/
, const char */
*file*/
, int /*how*/);
306 /*----- Creating and manipulating keys ------------------------------------*/
310 * Arguments: @key_file *f@ = pointer to key file
311 * @uint32 id@ = keyid to set
312 * @const char *type@ = the type of this key
313 * @time_t exp@ = when the key expires
314 * @int *err@ = where to store the error condition
316 * Returns: Key block containing new data, or null if it couldn't be
319 * Use: Attaches a new key to a key file. You must have a writable
320 * key file for this to work.
322 * The type is a key type string. This interface doesn't care
323 * about how type strings are formatted: it just treats them as
324 * opaque gobs of text. Clients are advised to choose some
325 * standard for representing key types, though.
327 * The expiry time should either be a time in the future, or the
328 * magic value @KEXP_FOREVER@ which means `never expire this
329 * key'. Be careful with `forever' keys. If I were you, I'd
330 * use a more sophisticated key management system than this for
333 * You have to set the actual key yourself.
336 extern key
*key_new(key_file */
*f*/
, uint32
/*id*/, const char */
*type*/
,
337 time_t /*exp*/, int */
*err*/
);
339 /* --- @key_delete@ --- *
341 * Arguments: @key_file *f@ = pointer to file block
342 * @key *k@ = key to delete
344 * Returns: Error code (one of the @KERR@ constants).
346 * Use: Removes the given key from the list. The key file must be
347 * writable. (Due to the horridness of the data structures,
348 * deleted keys aren't actually removed, just marked so that
349 * they can't be looked up or iterated over. One upshot of
350 * this is that they don't get written back to the file when
354 extern int key_delete(key_file */
*f*/
, 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 /*----- Setting and reading attributes ------------------------------------*/
392 /* --- @key_chkident@ --- *
394 * Arguments: @const char *p@ = pointer to a type string
396 * Returns: Zero if OK, -1 on error.
398 * Use: Checks whether an identification component string is OK.
401 extern int key_chkident(const char */
*p*/
);
403 /* --- @key_chkcomment@ --- *
405 * Arguments: @const char *p@ = pointer to a comment string
407 * Returns: Zero if OK, -1 on error.
409 * Use: Checks whether a comment string is OK.
412 extern int key_chkcomment(const char */
*p*/
);
414 /* --- @key_setcomment@ --- *
416 * Arguments: @key_file *f@ = pointer to key file block
417 * @key *k@ = pointer to key block
418 * @const char *c@ = pointer to comment to set, or zero
420 * Returns: Error code (one of the @KERR@ constants).
422 * Use: Replaces the key's current comment with a new one.
425 extern int key_setcomment(key_file */
*f*/
, key */
*k*/
, const char */
*c*/
);
427 /* --- @key_settag@ --- *
429 * Arguments: @key_file *f@ = pointer to key file block
430 * @key *k@ = pointer to key block
431 * @const char *tag@ = pointer to comment to set, or zero
433 * Returns: Error code (one of the @KERR@ constants).
435 * Use: Replaces the key's current tag with a new one.
438 extern int key_settag(key_file */
*f*/
, key */
*k*/
, const char */
*tag*/
);
440 /* --- @key_fulltag@ --- *
442 * Arguments: @key *k@ = pointer to key
443 * @dstr *d@ = pointer to destination string
447 * Use: Emits the key's full tag, which has the form
448 * `ID:TYPE[:TAG]'. This is used in the textual file format,
449 * and to identify passphrases for locked keys.
452 extern void key_fulltag(key */
*k*/
, dstr */
*d*/
);
454 /* --- @key_qtag@ --- *
456 * Arguments: @key_file *f@ = key file to find a key from
457 * @const char *tag@ = pointer to tag string
458 * @dstr *d@ = pointer to string for full tag name
459 * @key **k@ = where to store the key pointer
460 * @key_data **kd@ = where to store the key data pointer
462 * Returns: Zero if OK, nonzero if it failed.
464 * Use: Performs a full lookup on a qualified tag name. The tag is
465 * qualified by the names of subkeys, separated by dots. Hence,
466 * a qualified tag is ID|TAG[.TAG...]. The various result
467 * pointers can be null to indicate that the result isn't
471 extern int key_qtag(key_file */
*f*/
, const char */
*tag*/
,
472 dstr */
*d*/
, key
**/
*k*/
, key_data
**/
*kd*/
);
474 /* --- @key_getattr@ --- *
476 * Arguments: @key_file *f@ = pointer to file
477 * @key *k@ = pointer to key
478 * @const char *n@ = pointer to attribute name
480 * Returns: Pointer to attribute value, or null if not found.
482 * Use: Returns the value of a key attribute.
485 extern const char *key_getattr(key_file */
*f*/
, key */
*k*/
,
488 /* --- @key_putattr@ --- *
490 * Arguments: @key_file *f@ = pointer to file
491 * @key *k@ = pointer to key
492 * @const char *n@ = pointer to attribute name
493 * @const char *v@ = pointer to attribute value or null
495 * Returns: Error code (one of the @KERR@ constants).
497 * Use: Inserts an attribute on a key. If an attribute with the same
498 * name already exists, it is deleted. Setting a null value
499 * removes the attribute.
502 extern int key_putattr(key_file */
*f*/
, key */
*k*/
,
503 const char */
*n*/
, const char */
*v*/
);
505 /* --- @key_mkattriter@ --- *
507 * Arguments: @key_attriter *i@ = pointer to attribute iterator
508 * @key *k@ = pointer to key
512 * Use: Initializes an attribute iterator. The attributes are
513 * returned by @key_nextattr@.
516 extern void key_mkattriter(key_attriter */
*i*/
, key */
*k*/
);
518 /* --- @key_nextattr@ --- *
520 * Arguments: @key_attriter *i@ = pointer to attribute iterator
521 * @const char **n, **v@ = pointers to name and value
523 * Returns: Zero if no attribute available, or nonzero if returned OK.
525 * Use: Returns the next attribute.
528 extern int key_nextattr(key_attriter */
*i*/
,
529 const char **/
*n*/
, const char **/
*v*/
);
531 /*----- Searching and iterating -------------------------------------------*/
533 /* --- @key_bytype@ --- *
535 * Arguments: @key_file *f@ = key file we want a key from
536 * @const char *type@ = type string for desired key
538 * Returns: Pointer to the best key to use, or null.
540 * Use: Looks up a key by its type. Returns the key with the latest
541 * expiry time. This function will not return an expired key.
544 extern key
*key_bytype(key_file */
*f*/
, const char */
*type*/
);
546 /* --- @key_byid@ --- *
548 * Arguments: @key_file *f@ = key file to find a key from
549 * @uint32 id@ = id to look for
551 * Returns: Key with matching id.
553 * Use: Returns a key given its id. This function will return an
554 * expired key, but not a deleted one.
557 extern key
*key_byid(key_file */
*f*/
, uint32
/*id*/);
559 /* --- @key_bytag@ --- *
561 * Arguments: @key_file *f@ = key file to find a key from
562 * @const char *tag@ = pointer to tag string
564 * Returns: Key with matching id or tag.
566 * Use: Returns a key given its tag or id. This function will return
567 * an expired key, but not a deleted one.
570 extern key
*key_bytag(key_file */
*f*/
, const char */
*tag*/
);
572 /* --- @key_mkiter@ --- *
574 * Arguments: @key_iter *i@ = pointer to iterator object
575 * @key_file *f@ = pointer to file structure
579 * Use: Initializes a key iterator. The keys are returned by
583 extern void key_mkiter(key_iter */
*i*/
, key_file */
*f*/
);
585 /* --- @key_next@ --- *
587 * Arguments: @key_iter *i@ = pointer to iterator object
589 * Returns: Pointer to next key, or null.
591 * Use: Returns the next key in some arbitrary sequence.
594 extern key
*key_next(key_iter */
*i*/
);
596 /*----- Other functions ---------------------------------------------------*/
598 /* --- @key_moan@ --- *
600 * Arguments: @const char *file@ = name of the file
601 * @int line@ = line number in file
602 * @const char *msg@ = error message
603 * @void *p@ = argument pointer
607 * Use: Reports an error message about loading a key file.
610 extern void key_moan(const char */
*file*/
, int /*line*/,
611 const char */
*msg*/
, void */
*p*/
);
613 /* --- @key_strerror@ --- *
615 * Arguments: @int err@ = error code from @key_new@
617 * Returns: Pointer to error string.
619 * Use: Translates a @KERR@ error code into a human-readable string.
622 extern const char *key_strerror(int /*err*/);
624 /*----- That's all, folks -------------------------------------------------*/