3 * $Id: mptext-string.c,v 1.4 2004/04/01 12:50:09 mdw Exp $
5 * Reading and writing large integers on strings
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
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.
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.
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,
30 /*----- Revision history --------------------------------------------------*
32 * $Log: mptext-string.c,v $
33 * Revision 1.4 2004/04/01 12:50:09 mdw
34 * Add cyclic group abstraction, with test code. Separate off exponentation
35 * functions for better static linking. Fix a buttload of bugs on the way.
36 * Generally ensure that negative exponents do inversion correctly. Add
37 * table of standard prime-field subgroups. (Binary field subgroups are
38 * currently unimplemented but easy to add if anyone ever finds a good one.)
40 * Revision 1.3 2000/08/04 23:23:44 mdw
41 * Various <ctype.h> fixes.
43 * Revision 1.2 1999/12/22 15:56:21 mdw
44 * Make the buffer passed to `put' op constant.
46 * Revision 1.1 1999/11/17 18:02:16 mdw
47 * New multiprecision integer arithmetic suite.
51 /*----- Header files ------------------------------------------------------*/
57 /*----- Main code ---------------------------------------------------------*/
59 /* --- Operations table --- */
61 static int get(void *p
)
63 mptext_stringctx
*c
= p
;
66 return ((unsigned char)*c
->buf
++);
69 static void unget(int ch
, void *p
)
71 mptext_stringctx
*c
= p
;
76 static int put(const char *s
, size_t sz
, void *p
)
78 mptext_stringctx
*c
= p
;
80 if (sz
> c
->lim
- c
->buf
) {
85 memcpy(c
->buf
, s
, sz
);
91 const mptext_ops mptext_stringops
= { get
, unget
, put
};
93 /* --- Convenience functions --- */
95 mp
*mp_readstring(mp
*m
, const char *p
, char **end
, int radix
)
98 c
.buf
= (/*unconst */ char *)p
;
99 c
.lim
= c
.buf
+ strlen(p
);
100 m
= mp_read(m
, radix
, &mptext_stringops
, &c
);
106 int mp_writestring(mp
*m
, char *p
, size_t sz
, int radix
)
114 rc
= mp_write(m
, radix
, &mptext_stringops
, &c
);
119 /*----- That's all, folks -------------------------------------------------*/