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/* $Id: xdr_mpz_t.C,v 1.8 2003/02/02 22:44:16 dm Exp $ */
#include "arpc.h"
#include "bigint.h"
/*
* An external data representation format for MP_INTs.
*
* This is basically the same as opaque XDR data: Size followed by
* data followed by padding. However, the encoded size is always
* chosen to be a multiple of 4, so so the padding is never used.
*
* The external representation has the following three parts:
*
* size: 4-byte big-endian word indicating the number of bytes
* used to encode the number. The ENCODE operation rounds
* this up to the next multiple of 4.
*
* number: a size byte, 2's complement represantation of the MP_INT
* (The most significant bit is the sign bit. The number
* -1 is represented by size bytes of value 0xff - where
* size would most likely be 1.)
*
* padding: (4 - size) % 4 bytes of padding to make the whole thing
* a multiple of four bytes. (Since size is 0 bytes, the
* encoding will always have a zero-length padding.)
*/
bool_t
xdr_mpz_t (register XDR *xdrs, MP_INT *z)
{
u_int32_t size;
char *cp;
switch (xdrs->x_op) {
case XDR_ENCODE:
size = mpz_rawsize (z) + 3 & ~3;
if (!xdr_putint (xdrs, size))
return FALSE;
if (!(cp = (char *) XDR_INLINE (xdrs, size)))
return FALSE;
mpz_get_raw (cp, size, z);
break;
case XDR_DECODE:
if (!z->_mp_d)
mpz_init (z);
if (!xdr_getint (xdrs, size) || (int32_t) size < 0)
return FALSE;
if (!(cp = (char *) XDR_INLINE (xdrs, size + 3 & ~3)))
return FALSE;
mpz_set_raw (z, cp, size);
break;
case XDR_FREE:
if (z->_mp_d)
mpz_clear (z);
z->_mp_d = NULL;
}
return TRUE;
}
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