3 * Higher-level key unpacking
5 * (c) 2000 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Catacomb.
12 * Catacomb is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Library General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
17 * Catacomb is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU Library General Public License for more details.
22 * You should have received a copy of the GNU Library General Public
23 * License along with Catacomb; if not, write to the Free
24 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
28 /*----- Header files ------------------------------------------------------*/
30 #include <mLib/dstr.h>
35 /*----- Main code ---------------------------------------------------------*/
37 /* --- @key_fetchinit@ --- *
39 * Arguments: @const key_fetchdef *kf@ = pointer to base definition
40 * @key_packstruct *kps@ = pointer to destination packing def
41 * @void *p@ = pointer to destination block
43 * Returns: Pointer to packing definition.
45 * Use: Initializes a packing definition (@key_packdef@ structure).
46 * If @kps@ is null on entry, an appropriately sized block is
47 * allocated automatically. Otherwise it must be large enough.
50 static size_t kfcount(const key_fetchdef *kf)
62 key_packdef *key_fetchinit(const key_fetchdef *kf,
63 key_packstruct *kp, void *p)
65 size_t n = 1 + kfcount(kf);
70 /* --- If @kps@ is null, count the entries and allocate --- */
75 kp = xmalloc(n * sizeof(*kp));
76 kp->name = (char *)kp;
79 /* --- Fill in the top part --- */
81 kp->kp.e = KENC_STRUCT;
86 /* --- Initialize for the main loop --- */
92 /* --- Iterate over the entries in the table --- *
94 * The end of the target block is used as a stack to record where
95 * substructure is meant to occur. The integer @n@ is the depth of the
96 * stack; @kps@ is a full descending stack pointer. The @kp.p@ member of a
97 * stack element points back to an entry with substructure, the @kp.p@
98 * member of which refers to the @kf@ table for the substructure.
100 * This should all be about as clear as mud.
105 /* --- Blat out a level's worth --- */
111 if ((kf->e & KF_ENCMASK) != KENC_STRUCT)
112 kp->kp.p = cp + kf->off;
115 kp->kp.p = (void *)kf->kf;
125 /* --- Pop an entry from the stack --- */
128 key_packstruct *kkp = (kps++)->kp.p;
135 /* --- We're done --- */
140 /* --- @key_fetch@ --- *
142 * Arguments: @key_packdef *kp@ = pointer to packing structure
143 * @key *k@ = key file containing desired key
145 * Returns: Error code, or zero.
147 * Use: Fetches an unpacked key from a packed one.
150 int key_fetch(key_packdef *kp, key *k)
156 e = key_unpack(kp, k->k, &d);
161 /* --- @key_fetchbyname@ --- *
163 * Arguments: @key_packdef *kp@ = pointer to packing structure
164 * @key_file *kf@ = key file containing desired key
165 * @const char *tag@ = user's tag describing the key
167 * Returns: Error code, or zero.
169 * Use: Fetches a named key from a key file and unpacks it
173 int key_fetchbyname(key_packdef *kp, key_file *kf, const char *tag)
179 if (key_qtag(kf, tag, &d, 0, &kd))
182 e = key_unpack(kp, *kd, &d);
187 /* --- @key_fetchdone@ --- *
189 * Arguments: @key_packdef *kp@ = pointer to packing structure
193 * Use: Frees a packing structure. If the structure was allocated by
194 * @key_fetchinit@ then it is freed.
197 void key_fetchdone(key_packdef *kp)
199 key_packstruct *kps =
200 (key_packstruct *)(((char *)kp) - offsetof(key_packstruct, kp));
206 /*----- That's all, folks -------------------------------------------------*/