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1 | /* -*-c-*- |
2 | * |
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3 | * $Id$ |
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4 | * |
5 | * Higher-level key unpacking |
6 | * |
7 | * (c) 2000 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
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. |
18 | * |
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. |
23 | * |
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, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
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30 | /*----- Header files ------------------------------------------------------*/ |
31 | |
32 | #include <mLib/dstr.h> |
33 | |
34 | #include "key.h" |
35 | #include "key-data.h" |
36 | |
37 | /*----- Main code ---------------------------------------------------------*/ |
38 | |
39 | /* --- @key_fetchinit@ --- * |
40 | * |
41 | * Arguments: @const key_fetchdef *kf@ = pointer to base definition |
42 | * @key_packstruct *kps@ = pointer to destination packing def |
43 | * @void *p@ = pointer to destination block |
44 | * |
45 | * Returns: Pointer to packing definition. |
46 | * |
47 | * Use: Initializes a packing definition (@key_packdef@ structure). |
48 | * If @kps@ is null on entry, an appropriately sized block is |
49 | * allocated automatically. Otherwise it must be large enough. |
50 | */ |
51 | |
52 | static size_t kfcount(const key_fetchdef *kf) |
53 | { |
54 | size_t n = 1; |
55 | while (kf->name) { |
56 | n++; |
57 | if (kf->kf) |
58 | n += kfcount(kf->kf); |
59 | kf++; |
60 | } |
61 | return (n); |
62 | } |
63 | |
64 | key_packdef *key_fetchinit(const key_fetchdef *kf, |
65 | key_packstruct *kp, void *p) |
66 | { |
67 | size_t n = 1 + kfcount(kf); |
68 | key_packdef *kpd; |
69 | key_packstruct *kps; |
70 | char *cp = p; |
71 | |
72 | /* --- If @kps@ is null, count the entries and allocate --- */ |
73 | |
74 | if (kp) |
75 | kp->name = 0; |
76 | else { |
77 | kp = xmalloc(n * sizeof(*kp)); |
78 | kp->name = (char *)kp; |
79 | } |
80 | |
81 | /* --- Fill in the top part --- */ |
82 | |
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83 | kp->kp.e = KENC_STRUCT; |
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84 | kp->kp.p = &kp[1]; |
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85 | kp->kp.kd = 0; |
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86 | kpd = &kp->kp; |
87 | |
88 | /* --- Initialize for the main loop --- */ |
89 | |
90 | kps = kp + n; |
91 | n = 0; |
92 | kp++; |
93 | |
94 | /* --- Iterate over the entries in the table --- * |
95 | * |
96 | * The end of the target block is used as a stack to record where |
97 | * substructure is meant to occur. The integer @n@ is the depth of the |
98 | * stack; @kps@ is a full descending stack pointer. The @kp.p@ member of a |
99 | * stack element points back to an entry with substructure, the @kp.p@ |
100 | * member of which refers to the @kf@ table for the substructure. |
101 | * |
102 | * This should all be about as clear as mud. |
103 | */ |
104 | |
105 | for (;;) { |
106 | |
107 | /* --- Blat out a level's worth --- */ |
108 | |
109 | while (kf->name) { |
110 | kp->name = kf->name; |
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111 | kp->kp.e = kf->e; |
112 | kp->kp.kd = 0; |
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113 | if ((kf->e & KF_ENCMASK) != KENC_STRUCT) |
114 | kp->kp.p = cp + kf->off; |
115 | else { |
116 | (--kps)->kp.p = kp; |
117 | kp->kp.p = (void *)kf->kf; |
118 | n++; |
119 | } |
120 | kf++; |
121 | kp++; |
122 | } |
123 | (kp++)->name = 0; |
124 | if (!n) |
125 | break; |
126 | |
127 | /* --- Pop an entry from the stack --- */ |
128 | |
129 | { |
130 | key_packstruct *kkp = (kps++)->kp.p; |
131 | kf = kkp->kp.p; |
132 | kkp->kp.p = kp; |
133 | n--; |
134 | } |
135 | } |
136 | |
137 | /* --- We're done --- */ |
138 | |
139 | return (kpd); |
140 | } |
141 | |
142 | /* --- @key_fetch@ --- * |
143 | * |
144 | * Arguments: @key_packdef *kp@ = pointer to packing structure |
145 | * @key *k@ = key file containing desired key |
146 | * |
147 | * Returns: Error code, or zero. |
148 | * |
149 | * Use: Fetches an unpacked key from a packed one. |
150 | */ |
151 | |
152 | int key_fetch(key_packdef *kp, key *k) |
153 | { |
154 | dstr d = DSTR_INIT; |
155 | int e; |
156 | |
157 | key_fulltag(k, &d); |
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158 | e = key_unpack(kp, k->k, &d); |
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159 | dstr_destroy(&d); |
160 | return (e); |
161 | } |
162 | |
163 | /* --- @key_fetchbyname@ --- * |
164 | * |
165 | * Arguments: @key_packdef *kp@ = pointer to packing structure |
166 | * @key_file *kf@ = key file containing desired key |
167 | * @const char *tag@ = user's tag describing the key |
168 | * |
169 | * Returns: Error code, or zero. |
170 | * |
171 | * Use: Fetches a named key from a key file and unpacks it |
172 | * conveniently. |
173 | */ |
174 | |
175 | int key_fetchbyname(key_packdef *kp, key_file *kf, const char *tag) |
176 | { |
177 | dstr d = DSTR_INIT; |
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178 | key_data **kd; |
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179 | int e; |
180 | |
181 | if (key_qtag(kf, tag, &d, 0, &kd)) |
182 | e = KERR_NOTFOUND; |
183 | else |
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184 | e = key_unpack(kp, *kd, &d); |
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185 | dstr_destroy(&d); |
186 | return (e); |
187 | } |
188 | |
189 | /* --- @key_fetchdone@ --- * |
190 | * |
191 | * Arguments: @key_packdef *kp@ = pointer to packing structure |
192 | * |
193 | * Returns: --- |
194 | * |
195 | * Use: Frees a packing structure. If the structure was allocated by |
196 | * @key_fetchinit@ then it is freed. |
197 | */ |
198 | |
199 | void key_fetchdone(key_packdef *kp) |
200 | { |
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201 | key_packstruct *kps = |
202 | (key_packstruct *)(((char *)kp) - offsetof(key_packstruct, kp)); |
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203 | key_unpackdone(kp); |
204 | if (kps->name) |
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205 | xfree(kps); |
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206 | } |
207 | |
208 | /*----- That's all, folks -------------------------------------------------*/ |