/* -*-c-*-
*
- * $Id: buf.c,v 1.1 2003/10/11 21:02:33 mdw Exp $
+ * $Id$
*
* Buffer handling
*
* (c) 2001 Straylight/Edgeware
*/
-/*----- Licensing notice --------------------------------------------------*
+/*----- Licensing notice --------------------------------------------------*
*
* This file is part of Catacomb.
*
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
- *
+ *
* Catacomb is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Library General Public License for more details.
- *
+ *
* You should have received a copy of the GNU Library General Public
* License along with Catacomb; if not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: buf.c,v $
- * Revision 1.1 2003/10/11 21:02:33 mdw
- * Import buf stuff from tripe.
- *
- * Revision 1.4 2001/06/19 22:09:54 mdw
- * Expose interface, for use in the proxy.
- *
- * Revision 1.3 2001/03/03 12:06:48 mdw
- * Use 16-bit lengths on MPs, since there's a packet limit of 64K anyway.
- *
- * Revision 1.2 2001/02/16 21:23:20 mdw
- * Various minor changes. Check that MPs are in canonical form when
- * loading.
- *
- * Revision 1.1 2001/02/03 20:26:37 mdw
- * Initial checkin.
- *
- */
-
/*----- Header files ------------------------------------------------------*/
#include <string.h>
-#include <catacomb/mp.h>
-
+#include "mp.h"
+#include "ec.h"
#include "buf.h"
/*----- Main code ---------------------------------------------------------*/
-/* --- @buf_init@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @void *p@ = pointer to a buffer
- * @size_t sz@ = size of the buffer
- *
- * Returns: ---
- *
- * Use: Initializes the buffer block appropriately.
- */
-
-void buf_init(buf *b, void *p, size_t sz)
-{
- b->base = b->p = p;
- b->limit = b->p + sz;
- b->f = 0;
-}
-
-/* --- @buf_break@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- *
- * Returns: Some negative value.
- *
- * Use: Marks a buffer as broken.
- */
-
-int buf_break(buf *b) { b->f |= BF_BROKEN; return (-1); }
-
-/* --- @buf_flip@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- *
- * Returns: ---
- *
- * Use: Flips a buffer so that if you've just been writing to it,
- * you can now read from the bit you've written.
- */
-
-void buf_flip(buf *b)
-{
- b->limit = b->p;
- b->p = b->base;
-}
-
-/* --- @buf_ensure@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @size_t sz@ = size of data wanted
- *
- * Returns: Zero if it worked, nonzero if there wasn't enough space.
- *
- * Use: Ensures that there are @sz@ bytes still in the buffer.
- */
-
-int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); }
-
-/* --- @buf_get@ --- *
+/* --- @buf_getmp@ --- *
*
* Arguments: @buf *b@ = pointer to a buffer block
- * @size_t sz@ = size of the buffer
*
- * Returns: Pointer to the place in the buffer.
+ * Returns: A multiprecision integer, or null if there wasn't one there.
*
- * Use: Reserves a space in the buffer of the requested size, and
- * returns its start address.
+ * Use: Gets a multiprecision integer from a buffer.
*/
-void *buf_get(buf *b, size_t sz)
+mp *buf_getmp(buf *b)
{
- void *p;
- if (BENSURE(b, sz))
+ uint16 sz;
+ size_t n;
+ mp *m;
+ if (buf_getu16(b, &sz) || buf_ensure(b, sz))
+ return (0);
+ m = mp_loadb(MP_NEW, BCUR(b), sz);
+ n = mp_octets(m);
+ if (n != sz && n != 0 && sz != 1) {
+ mp_drop(m);
return (0);
- p = BCUR(b);
+ }
BSTEP(b, sz);
- return (p);
+ return (m);
}
-/* --- @buf_put@ --- *
+/* --- @buf_putmp@ --- *
*
* Arguments: @buf *b@ = pointer to a buffer block
- * @const void *p@ = pointer to a buffer
- * @size_t sz@ = size of the buffer
+ * @mp *m@ = a multiprecision integer
*
* Returns: Zero if it worked, nonzero if there wasn't enough space.
*
- * Use: Fetches data from some place and puts it in the buffer
+ * Use: Puts a multiprecision integer to a buffer.
*/
-int buf_put(buf *b, const void *p, size_t sz)
+int buf_putmp(buf *b, mp *m)
{
- if (BENSURE(b, sz))
+ size_t sz = mp_octets(m);
+ assert(sz < MASK16);
+ if (!sz) sz = 1;
+ if (buf_putu16(b, sz) || buf_ensure(b, sz))
return (-1);
- memcpy(BCUR(b), p, sz);
+ mp_storeb(m, BCUR(b), sz);
BSTEP(b, sz);
return (0);
}
-/* --- @buf_getbyte@ --- *
+/* --- @buf_getec@ --- *
*
* Arguments: @buf *b@ = pointer to a buffer block
+ * @ec *p@ = where to put the point
*
- * Returns: A byte, or less than zero if there wasn't a byte there.
+ * Returns: Zero if it worked, nonzero if it failed.
*
- * Use: Gets a single byte from a buffer.
+ * Use: Gets a multiprecision integer from a buffer. The point must
+ * be initialized.
*/
-int buf_getbyte(buf *b)
+int buf_getec(buf *b, ec *p)
{
- if (BENSURE(b, 1))
- return (-1);
- return (*b->p++);
-}
-
-/* --- @buf_putbyte@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @int ch@ = byte to write
- *
- * Returns: Zero if OK, nonzero if there wasn't enough space.
- *
- * Use: Puts a single byte in a buffer.
- */
-
-int buf_putbyte(buf *b, int ch)
-{
- if (BENSURE(b, 1))
- return (-1);
- *b->p++ = ch;
- return (0);
-}
-
-/* --- @buf_getu16@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @uint16 *w@ = where to put the word
- *
- * Returns: Zero if OK, or nonzero if there wasn't a word there.
- *
- * Use: Gets a 16-bit word from a buffer.
- */
-
-int buf_getu16(buf *b, uint16 *w)
-{
- if (BENSURE(b, 2))
- return (-1);
- *w = LOAD16(b->p);
- BSTEP(b, 2);
- return (0);
-}
-
-/* --- @buf_putu16@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @uint16 w@ = word to write
- *
- * Returns: Zero if OK, nonzero if there wasn't enough space.
- *
- * Use: Puts a 16-but word in a buffer.
- */
-
-int buf_putu16(buf *b, uint16 w)
-{
- if (BENSURE(b, 2))
- return (-1);
- STORE16(b->p, w);
- BSTEP(b, 2);
- return (0);
-}
-
-/* --- @buf_getu32@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @uint32 *w@ = where to put the word
- *
- * Returns: Zero if OK, or nonzero if there wasn't a word there.
- *
- * Use: Gets a 32-bit word from a buffer.
- */
-
-int buf_getu32(buf *b, uint32 *w)
-{
- if (BENSURE(b, 4))
- return (-1);
- *w = LOAD32(b->p);
- BSTEP(b, 4);
- return (0);
-}
-
-/* --- @buf_putu32@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @uint32 w@ = word to write
- *
- * Returns: Zero if OK, nonzero if there wasn't enough space.
- *
- * Use: Puts a 32-but word in a buffer.
- */
-
-int buf_putu32(buf *b, uint32 w)
-{
- if (BENSURE(b, 4))
- return (-1);
- STORE32(b->p, w);
- BSTEP(b, 4);
- return (0);
-}
-
-/* --- @buf_getmp@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- *
- * Returns: A multiprecision integer, or null if there wasn't one there.
- *
- * Use: Gets a multiprecision integer from a buffer.
- */
-
-mp *buf_getmp(buf *b)
-{
- uint16 sz;
- mp *m;
- if (buf_getu16(b, &sz) || buf_ensure(b, sz))
- return (0);
- m = mp_loadb(MP_NEW, BCUR(b), sz);
- if (mp_octets(m) != sz) {
- mp_drop(m);
- return (0);
+ mp *x = 0, *y = 0;
+ uint16 n;
+ if (buf_ensure(b, 2)) return (-1);
+ n = LOAD16(BCUR(b)); if (!n) { BSTEP(b, 2); EC_SETINF(p); return (0); }
+ if ((x = buf_getmp(b)) == 0 || (y = buf_getmp(b)) == 0) {
+ mp_drop(x); mp_drop(y); return (-1);
}
- BSTEP(b, sz);
- return (m);
+ EC_DESTROY(p); p->x = x; p->y = y; p->z = 0;
+ return (0);
}
-/* --- @buf_putmp@ --- *
+/* --- @buf_putec@ --- *
*
* Arguments: @buf *b@ = pointer to a buffer block
- * @mp *m@ = a multiprecision integer
+ * @ec *p@ = an elliptic curve point
*
* Returns: Zero if it worked, nonzero if there wasn't enough space.
*
- * Use: Puts a multiprecision integer to a buffer.
+ * Use: Puts an elliptic curve point to a buffer.
*/
-int buf_putmp(buf *b, mp *m)
+int buf_putec(buf *b, ec *p)
{
- size_t sz = mp_octets(m);
- assert(sz < MASK16);
- if (buf_putu16(b, sz) || buf_ensure(b, sz))
- return (-1);
- mp_storeb(m, BCUR(b), sz);
- BSTEP(b, sz);
+ if (EC_ATINF(p)) return (buf_putu16(b, 0));
+ if (buf_putmp(b, p->x) || buf_putmp(b, p->y)) return (-1);
return (0);
}