410c8acf |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: buf.c,v 1.1 2001/02/03 20:26:37 mdw Exp $ |
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 $ |
32 | * Revision 1.1 2001/02/03 20:26:37 mdw |
33 | * Initial checkin. |
34 | * |
35 | */ |
36 | |
37 | /*----- Header files ------------------------------------------------------*/ |
38 | |
39 | #include "tripe.h" |
40 | |
41 | /*----- Main code ---------------------------------------------------------*/ |
42 | |
43 | /* --- @buf_init@ --- * |
44 | * |
45 | * Arguments: @buf *b@ = pointer to a buffer block |
46 | * @void *p@ = pointer to a buffer |
47 | * @size_t sz@ = size of the buffer |
48 | * |
49 | * Returns: --- |
50 | * |
51 | * Use: Initializes the buffer block appropriately. |
52 | */ |
53 | |
54 | void buf_init(buf *b, void *p, size_t sz) |
55 | { |
56 | b->base = b->p = p; |
57 | b->limit = b->p + sz; |
58 | b->f = 0; |
59 | } |
60 | |
61 | /* --- @buf_break@ --- * |
62 | * |
63 | * Arguments: @buf *b@ = pointer to a buffer block |
64 | * |
65 | * Returns: Some negative value. |
66 | * |
67 | * Use: Marks a buffer as broken. |
68 | */ |
69 | |
70 | int buf_break(buf *b) { b->f |= BF_BROKEN; return (-1); } |
71 | |
72 | /* --- @buf_ensure@ --- * |
73 | * |
74 | * Arguments: @buf *b@ = pointer to a buffer block |
75 | * @size_t sz@ = size of data wanted |
76 | * |
77 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
78 | * |
79 | * Use: Ensures that there are @sz@ bytes still in the buffer. |
80 | */ |
81 | |
82 | int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); } |
83 | |
84 | /* --- @buf_get@ --- * |
85 | * |
86 | * Arguments: @buf *b@ = pointer to a buffer block |
87 | * @void *p@ = pointer to a buffer |
88 | * @size_t sz@ = size of the buffer |
89 | * |
90 | * Returns: Zero if it worked, nonzero if there wasn't enough data. |
91 | * |
92 | * Use: Fetches data from the buffer into some other place. |
93 | */ |
94 | |
95 | int buf_get(buf *b, void *p, size_t sz) |
96 | { |
97 | if (BENSURE(b, sz)) |
98 | return (-1); |
99 | memcpy(p, BCUR(b), sz); |
100 | BSTEP(b, sz); |
101 | return (0); |
102 | } |
103 | |
104 | /* --- @buf_put@ --- * |
105 | * |
106 | * Arguments: @buf *b@ = pointer to a buffer block |
107 | * @const void *p@ = pointer to a buffer |
108 | * @size_t sz@ = size of the buffer |
109 | * |
110 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
111 | * |
112 | * Use: Fetches data from some place and puts it in the buffer |
113 | */ |
114 | |
115 | int buf_put(buf *b, const void *p, size_t sz) |
116 | { |
117 | if (BENSURE(b, sz)) |
118 | return (-1); |
119 | memcpy(BCUR(b), p, sz); |
120 | BSTEP(b, sz); |
121 | return (0); |
122 | } |
123 | |
124 | /* --- @buf_getbyte@ --- * |
125 | * |
126 | * Arguments: @buf *b@ = pointer to a buffer block |
127 | * |
128 | * Returns: A byte, or less than zero if there wasn't a byte there. |
129 | * |
130 | * Use: Gets a single byte from a buffer. |
131 | */ |
132 | |
133 | int buf_getbyte(buf *b) |
134 | { |
135 | if (BENSURE(b, 1)) |
136 | return (-1); |
137 | return (*b->p++); |
138 | } |
139 | |
140 | /* --- @buf_putbyte@ --- * |
141 | * |
142 | * Arguments: @buf *b@ = pointer to a buffer block |
143 | * @int ch@ = byte to write |
144 | * |
145 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
146 | * |
147 | * Use: Puts a single byte in a buffer. |
148 | */ |
149 | |
150 | int buf_putbyte(buf *b, int ch) |
151 | { |
152 | if (BENSURE(b, 1)) |
153 | return (-1); |
154 | *b->p++ = ch; |
155 | return (0); |
156 | } |
157 | |
158 | /* --- @buf_getword@ --- * |
159 | * |
160 | * Arguments: @buf *b@ = pointer to a buffer block |
161 | * @uint32 *w@ = where to put the word |
162 | * |
163 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
164 | * |
165 | * Use: Gets a 32-bit word from a buffer. |
166 | */ |
167 | |
168 | int buf_getword(buf *b, uint32 *w) |
169 | { |
170 | if (BENSURE(b, 4)) |
171 | return (-1); |
172 | *w = LOAD32(b->p); |
173 | BSTEP(b, 4); |
174 | return (0); |
175 | } |
176 | |
177 | /* --- @buf_putword@ --- * |
178 | * |
179 | * Arguments: @buf *b@ = pointer to a buffer block |
180 | * @uint32 w@ = word to write |
181 | * |
182 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
183 | * |
184 | * Use: Puts a 32-but word in a buffer. |
185 | */ |
186 | |
187 | int buf_putword(buf *b, uint32 w) |
188 | { |
189 | if (BENSURE(b, 4)) |
190 | return (-1); |
191 | STORE32(b->p, w); |
192 | BSTEP(b, 4); |
193 | return (0); |
194 | } |
195 | |
196 | /* --- @buf_getmp@ --- * |
197 | * |
198 | * Arguments: @buf *b@ = pointer to a buffer block |
199 | * |
200 | * Returns: A multiprecision integer, or null if there wasn't one there. |
201 | * |
202 | * Use: Gets a multiprecision integer from a buffer. |
203 | */ |
204 | |
205 | mp *buf_getmp(buf *b, mp *d) |
206 | { |
207 | uint32 sz; |
208 | if (buf_getword(b, &sz) || buf_ensure(b, sz)) |
209 | return (0); |
210 | d = mp_loadb(d, BCUR(b), sz); |
211 | BSTEP(b, sz); |
212 | return (d); |
213 | } |
214 | |
215 | /* --- @buf_putmp@ --- * |
216 | * |
217 | * Arguments: @buf *b@ = pointer to a buffer block |
218 | * @mp *m@ = a multiprecision integer |
219 | * |
220 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
221 | * |
222 | * Use: Puts a multiprecision integer to a buffer. |
223 | */ |
224 | |
225 | int buf_putmp(buf *b, mp *m) |
226 | { |
227 | size_t sz = mp_octets(m); |
228 | if (buf_putword(b, sz) || buf_ensure(b, sz)) |
229 | return (-1); |
230 | mp_storeb(m, BCUR(b), sz); |
231 | BSTEP(b, sz); |
232 | return (0); |
233 | } |
234 | |
235 | /*----- That's all, folks -------------------------------------------------*/ |