410c8acf |
1 | /* -*-c-*- |
2 | * |
cfc354fd |
3 | * $Id: buf.c,v 1.2 2001/02/16 21:23:20 mdw Exp $ |
410c8acf |
4 | * |
5 | * Buffer handling |
6 | * |
7 | * (c) 2001 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Trivial IP Encryption (TrIPE). |
13 | * |
14 | * TrIPE is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * TrIPE 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 General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
25 | * along with TrIPE; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | */ |
28 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: buf.c,v $ |
cfc354fd |
32 | * Revision 1.2 2001/02/16 21:23:20 mdw |
33 | * Various minor changes. Check that MPs are in canonical form when |
34 | * loading. |
35 | * |
410c8acf |
36 | * Revision 1.1 2001/02/03 20:26:37 mdw |
37 | * Initial checkin. |
38 | * |
39 | */ |
40 | |
41 | /*----- Header files ------------------------------------------------------*/ |
42 | |
43 | #include "tripe.h" |
44 | |
45 | /*----- Main code ---------------------------------------------------------*/ |
46 | |
47 | /* --- @buf_init@ --- * |
48 | * |
49 | * Arguments: @buf *b@ = pointer to a buffer block |
50 | * @void *p@ = pointer to a buffer |
51 | * @size_t sz@ = size of the buffer |
52 | * |
53 | * Returns: --- |
54 | * |
55 | * Use: Initializes the buffer block appropriately. |
56 | */ |
57 | |
58 | void buf_init(buf *b, void *p, size_t sz) |
59 | { |
60 | b->base = b->p = p; |
61 | b->limit = b->p + sz; |
62 | b->f = 0; |
63 | } |
64 | |
65 | /* --- @buf_break@ --- * |
66 | * |
67 | * Arguments: @buf *b@ = pointer to a buffer block |
68 | * |
69 | * Returns: Some negative value. |
70 | * |
71 | * Use: Marks a buffer as broken. |
72 | */ |
73 | |
74 | int buf_break(buf *b) { b->f |= BF_BROKEN; return (-1); } |
75 | |
cfc354fd |
76 | /* --- @buf_flip@ --- * |
77 | * |
78 | * Arguments: @buf *b@ = pointer to a buffer block |
79 | * |
80 | * Returns: --- |
81 | * |
82 | * Use: Flips a buffer so that if you've just been writing to it, |
83 | * you can now read from the bit you've written. |
84 | */ |
85 | |
86 | void buf_flip(buf *b) |
87 | { |
88 | b->limit = b->p; |
89 | b->p = b->base; |
90 | } |
91 | |
410c8acf |
92 | /* --- @buf_ensure@ --- * |
93 | * |
94 | * Arguments: @buf *b@ = pointer to a buffer block |
95 | * @size_t sz@ = size of data wanted |
96 | * |
97 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
98 | * |
99 | * Use: Ensures that there are @sz@ bytes still in the buffer. |
100 | */ |
101 | |
102 | int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); } |
103 | |
104 | /* --- @buf_get@ --- * |
105 | * |
106 | * Arguments: @buf *b@ = pointer to a buffer block |
410c8acf |
107 | * @size_t sz@ = size of the buffer |
108 | * |
cfc354fd |
109 | * Returns: Pointer to the place in the buffer. |
410c8acf |
110 | * |
cfc354fd |
111 | * Use: Reserves a space in the buffer of the requested size, and |
112 | * returns its start address. |
410c8acf |
113 | */ |
114 | |
cfc354fd |
115 | void *buf_get(buf *b, size_t sz) |
410c8acf |
116 | { |
cfc354fd |
117 | void *p; |
410c8acf |
118 | if (BENSURE(b, sz)) |
cfc354fd |
119 | return (0); |
120 | p = BCUR(b); |
410c8acf |
121 | BSTEP(b, sz); |
cfc354fd |
122 | return (p); |
410c8acf |
123 | } |
124 | |
125 | /* --- @buf_put@ --- * |
126 | * |
127 | * Arguments: @buf *b@ = pointer to a buffer block |
128 | * @const void *p@ = pointer to a buffer |
129 | * @size_t sz@ = size of the buffer |
130 | * |
131 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
132 | * |
133 | * Use: Fetches data from some place and puts it in the buffer |
134 | */ |
135 | |
136 | int buf_put(buf *b, const void *p, size_t sz) |
137 | { |
138 | if (BENSURE(b, sz)) |
139 | return (-1); |
140 | memcpy(BCUR(b), p, sz); |
141 | BSTEP(b, sz); |
142 | return (0); |
143 | } |
144 | |
145 | /* --- @buf_getbyte@ --- * |
146 | * |
147 | * Arguments: @buf *b@ = pointer to a buffer block |
148 | * |
149 | * Returns: A byte, or less than zero if there wasn't a byte there. |
150 | * |
151 | * Use: Gets a single byte from a buffer. |
152 | */ |
153 | |
154 | int buf_getbyte(buf *b) |
155 | { |
156 | if (BENSURE(b, 1)) |
157 | return (-1); |
158 | return (*b->p++); |
159 | } |
160 | |
161 | /* --- @buf_putbyte@ --- * |
162 | * |
163 | * Arguments: @buf *b@ = pointer to a buffer block |
164 | * @int ch@ = byte to write |
165 | * |
166 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
167 | * |
168 | * Use: Puts a single byte in a buffer. |
169 | */ |
170 | |
171 | int buf_putbyte(buf *b, int ch) |
172 | { |
173 | if (BENSURE(b, 1)) |
174 | return (-1); |
175 | *b->p++ = ch; |
176 | return (0); |
177 | } |
178 | |
179 | /* --- @buf_getword@ --- * |
180 | * |
181 | * Arguments: @buf *b@ = pointer to a buffer block |
182 | * @uint32 *w@ = where to put the word |
183 | * |
184 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
185 | * |
186 | * Use: Gets a 32-bit word from a buffer. |
187 | */ |
188 | |
189 | int buf_getword(buf *b, uint32 *w) |
190 | { |
191 | if (BENSURE(b, 4)) |
192 | return (-1); |
193 | *w = LOAD32(b->p); |
194 | BSTEP(b, 4); |
195 | return (0); |
196 | } |
197 | |
198 | /* --- @buf_putword@ --- * |
199 | * |
200 | * Arguments: @buf *b@ = pointer to a buffer block |
201 | * @uint32 w@ = word to write |
202 | * |
203 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
204 | * |
205 | * Use: Puts a 32-but word in a buffer. |
206 | */ |
207 | |
208 | int buf_putword(buf *b, uint32 w) |
209 | { |
210 | if (BENSURE(b, 4)) |
211 | return (-1); |
212 | STORE32(b->p, w); |
213 | BSTEP(b, 4); |
214 | return (0); |
215 | } |
216 | |
217 | /* --- @buf_getmp@ --- * |
218 | * |
219 | * Arguments: @buf *b@ = pointer to a buffer block |
220 | * |
221 | * Returns: A multiprecision integer, or null if there wasn't one there. |
222 | * |
223 | * Use: Gets a multiprecision integer from a buffer. |
224 | */ |
225 | |
cfc354fd |
226 | mp *buf_getmp(buf *b) |
410c8acf |
227 | { |
228 | uint32 sz; |
cfc354fd |
229 | mp *m; |
410c8acf |
230 | if (buf_getword(b, &sz) || buf_ensure(b, sz)) |
231 | return (0); |
cfc354fd |
232 | m = mp_loadb(MP_NEW, BCUR(b), sz); |
233 | if (mp_octets(m) != sz) { |
234 | mp_drop(m); |
235 | return (0); |
236 | } |
410c8acf |
237 | BSTEP(b, sz); |
cfc354fd |
238 | return (m); |
410c8acf |
239 | } |
240 | |
241 | /* --- @buf_putmp@ --- * |
242 | * |
243 | * Arguments: @buf *b@ = pointer to a buffer block |
244 | * @mp *m@ = a multiprecision integer |
245 | * |
246 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
247 | * |
248 | * Use: Puts a multiprecision integer to a buffer. |
249 | */ |
250 | |
251 | int buf_putmp(buf *b, mp *m) |
252 | { |
253 | size_t sz = mp_octets(m); |
254 | if (buf_putword(b, sz) || buf_ensure(b, sz)) |
255 | return (-1); |
256 | mp_storeb(m, BCUR(b), sz); |
257 | BSTEP(b, sz); |
258 | return (0); |
259 | } |
260 | |
261 | /*----- That's all, folks -------------------------------------------------*/ |