3 * $Id: tx.c,v 1.2 1997/08/04 10:24:25 mdw Exp $
5 * Transfer for keys and other large integers
7 * (c) 1997 Mark Wooding
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of `become'
14 * `Become' 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.
19 * `Become' 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.
24 * You should have received a copy of the GNU General Public License
25 * along with `become'; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.2 1997/08/04 10:24:25 mdw
33 * Sources placed under CVS control.
35 * Revision 1.1 1997/07/21 13:47:43 mdw
40 /*----- Header files ------------------------------------------------------*/
42 /* --- ANSI headers --- */
49 /* --- Local headers --- */
54 /*----- Main code ---------------------------------------------------------*/
56 /* --- @tx_getBits@ --- *
58 * Arguments: @unsigned char *k@ = pointer to key array to unpack into
59 * @size_t sz@ = number of bits to read (elements in array)
60 * @FILE *fp@ = stream to read from
64 * Use: Reads a number of bits into an array. The least significant
65 * bits of the final word are cleared to zero.
68 void tx_getBits(unsigned char *k
, size_t sz
, FILE *fp
)
73 size_t wsz
= (size_t)((sz
+ 7ul) & ~7ul);
76 while ((t
= getc(fp
)) != EOF
) {
78 /* --- Allow separators for readbility --- */
83 /* --- Standard converting-from-hex-digit code --- *
85 * Assumes that 'a'--'f' and 'A'--'F' are contiguous and in order, in
86 * addition to the guarantee that '0'--'9' are like this. The assumption
87 * is true in ASCII (and character sets based thereon) and EBCDIC.
92 if (ch
> 9) ch
-= 'A' - '0' - 10;
93 if (ch
> 15) ch
-= 'a' - 'A';
96 /* --- Accumulate and maybe store --- */
107 /* --- Pad the rest out with zeros --- */
118 /* --- @tx_putBits@ --- *
120 * Arguments: @unsigned char *k@ = pointer to key block
121 * @size_t sz@ = number of bits to write
122 * @FILE *fp@ = pointer to stream to write on
126 * Use: Complements @tx_getBits@ above. Writes a number of bits
127 * to a file in an easy-to-read and transportable format (hex!)
130 void tx_putBits(unsigned char *k
, size_t sz
, FILE *fp
)
132 const static char hex
[16] = "0123456789abcdef";
137 /* --- Don't do anything unless we have to --- */
142 /* --- Now decide where to `dash' the output --- */
146 else if (sz
% 40 == 0)
151 /* --- Start writing values out --- */
157 /* --- Write next byte out --- */
160 putc(hex
[(i
>> 4) & 0x0fu
], fp
);
161 putc(hex
[(i
>> 0) & 0x0fu
], fp
);
163 /* --- If done, stop now --- */
165 if (sz
-= 8, sz
== 0)
168 /* --- If need a dash, print one --- */
176 /* --- Print the final newline --- */
181 /*----- That's all, folks -------------------------------------------------*/