/* -*-c-*-
*
- * $Id: mpmont.h,v 1.3 1999/12/10 23:29:48 mdw Exp $
+ * $Id$
*
* Montgomery reduction
*
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: mpmont.h,v $
- * Revision 1.3 1999/12/10 23:29:48 mdw
- * Change header file guard names.
- *
- * Revision 1.2 1999/11/19 13:17:43 mdw
- * Add extra interface to exponentiation which returns a Montgomerized
- * result. Add simultaneous exponentiation interface.
- *
- * Revision 1.1 1999/11/17 18:02:16 mdw
- * New multiprecision integer arithmetic suite.
- *
- */
-
#ifndef CATACOMB_MPMONT_H
#define CATACOMB_MPMONT_H
typedef struct mpmont {
mp *m; /* Modulus */
- mpw mi; /* %$-m^{-1} \bmod b$% */
- size_t shift; /* %$\log_2 R$% */
+ mp *mi; /* %$-m^{-1} \bmod R$% */
+ size_t n; /* %$\log_b R$% */
mp *r, *r2; /* %$R \bmod m$%, %$R^2 \bmod m$% */
} mpmont;
-/* --- A base/exponent pair for @mpmont_mexp@ --- */
-
-typedef struct mpmont_factor {
- mp *base;
- mp *exp;
-} mpmont_factor;
-
/*----- Functions provided ------------------------------------------------*/
/* --- @mpmont_create@ --- *
* Arguments: @mpmont *mm@ = pointer to Montgomery reduction context
* @mp *m@ = modulus to use
*
- * Returns: ---
+ * Returns: Zero on success, nonzero on error.
*
* Use: Initializes a Montgomery reduction context ready for use.
* The argument @m@ must be a positive odd integer.
*/
-extern void mpmont_create(mpmont */*mm*/, mp */*m*/);
+extern int mpmont_create(mpmont */*mm*/, mp */*m*/);
/* --- @mpmont_destroy@ --- *
*
* @mp *a@ = base
* @mp *e@ = exponent
*
- * Returns: Result, %$a^e R \bmod m$%. This is useful if further modular
- * arithmetic is to be performed on the result.
+ * Returns: Result, %$(a R^{-1})^e R \bmod m$%. This is useful if
+ * further modular arithmetic is to be performed on the result.
*/
extern mp *mpmont_expr(mpmont */*mm*/, mp */*d*/, mp */*a*/, mp */*e*/);
*
* Arguments: @mpmont *mm@ = pointer to Montgomery reduction context
* @mp *d@ = fake destination
- * @mpmont_factor *f@ = pointer to array of factors
+ * @const mp_expfactor *f@ = pointer to array of factors
* @size_t n@ = number of factors supplied
*
* Returns: If the bases are %$g_0, g_1, \ldots, g_{n-1}$% and the
* exponents are %$e_0, e_1, \ldots, e_{n-1}$% then the result
* is:
*
- * %$g_0^{e_0} g_1^{e_1} \ldots g_{n-1}^{e_{n-1}} R \bmod m$%
+ * %$g_0^{e_0} g_1^{e_1} \ldots g_{n-1}^{e_{n-1}} \bmod m$%
+ *
+ *
+ * except that the %$g_i$% and result are in Montgomery form.
*/
extern mp *mpmont_mexpr(mpmont */*mm*/, mp */*d*/,
- mpmont_factor */*f*/, size_t /*n*/);
+ const mp_expfactor */*f*/, size_t /*n*/);
/* --- @mpmont_mexp@ --- *
*
* Arguments: @mpmont *mm@ = pointer to Montgomery reduction context
* @mp *d@ = fake destination
- * @mpmont_factor *f@ = pointer to array of factors
+ * @const mp_expfactor *f@ = pointer to array of factors
* @size_t n@ = number of factors supplied
*
* Returns: Product of bases raised to exponents, all mod @m@.
*/
extern mp *mpmont_mexp(mpmont */*mm*/, mp */*d*/,
- mpmont_factor */*f*/, size_t /*n*/);
+ const mp_expfactor */*f*/, size_t /*n*/);
/*----- That's all, folks -------------------------------------------------*/