--- /dev/null
+/* -*-c-*-
+ *
+ * Multiple simultaneous exponentiations
+ *
+ * (c) 1999 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * 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.
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include "mp.h"
+#include "mpmont.h"
+
+#define EXP_WINSZ 3
+#include "mpmont-exp.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @mpmont_mexpr@ --- *
+ *
+ * Arguments: @mpmont *mm@ = pointer to Montgomery reduction context
+ * @mp *d@ = fake destination
+ * @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:
+ *
+ * %$g_0^{e_0} g_1^{e_1} \ldots g_{n-1}^{e_{n-1}} \bmod m$%
+ *
+ * except that the %$g_i$% and result are in Montgomery form.
+ */
+
+static mp *mexpr(mpmont *mm, mp *d, mp_expfactor *f, size_t n)
+{
+ mp *a = MP_COPY(mm->r);
+ mp *spare = MP_NEW;
+ size_t i;
+
+ for (i = 0; i < n; i++) {
+ mp *t;
+ if (f[i].exp->f & MP_BURN)
+ spare = MP_NEWSEC;
+ if (MP_NEGP(f[i].exp)) {
+ t = mpmont_reduce(mm, f[i].base, f[i].base);
+ t = mp_modinv(t, t, mm->m);
+ f[i].base = mpmont_mul(mm, t, t, mm->r2);
+ }
+ }
+ EXP_SIMUL(a, f, n);
+ mp_drop(d);
+ mp_drop(spare);
+ for (i = 0; i < n; i++)
+ MP_DROP(f[i].base);
+ xfree(f);
+ return (a);
+}
+
+mp *mpmont_mexpr(mpmont *mm, mp *d, const mp_expfactor *f, size_t n)
+{
+ mp_expfactor *ff = xmalloc(n * sizeof(mp_expfactor));
+ size_t i;
+
+ for (i = 0; i < n; i++) {
+ ff[i].base = MP_COPY(f[i].base);
+ ff[i].exp = f[i].exp;
+ }
+ return (mexpr(mm, d, ff, n));
+}
+
+/* --- @mpmont_mexp@ --- *
+ *
+ * Arguments: @mpmont *mm@ = pointer to Montgomery reduction context
+ * @mp *d@ = fake destination
+ * @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@.
+ *
+ * Use: Convenient interface over @mpmont_mexpr@.
+ */
+
+mp *mpmont_mexp(mpmont *mm, mp *d, const mp_expfactor *f, size_t n)
+{
+ mp_expfactor *ff = xmalloc(n * sizeof(mp_expfactor));
+ size_t i;
+
+ for (i = 0; i < n; i++) {
+ ff[i].base = mpmont_mul(mm, MP_NEW, f[i].base, mm->r2);
+ ff[i].exp = f[i].exp;
+ }
+ d = mexpr(mm, d, ff, n);
+ return (mpmont_reduce(mm, d, d));
+}
+
+/*----- Test rig ----------------------------------------------------------*/
+
+#ifdef TEST_RIG
+
+#include <mLib/testrig.h>
+
+static int verify(size_t n, dstr *v)
+{
+ mp *m = *(mp **)v[0].buf;
+ mp_expfactor *f = xmalloc(n * sizeof(*f));
+ mp *r, *rr;
+ size_t i, j;
+ mpmont mm;
+ int ok = 1;
+
+ j = 1;
+ for (i = 0; i < n; i++) {
+ f[i].base = *(mp **)v[j++].buf;
+ f[i].exp = *(mp **)v[j++].buf;
+ }
+
+ rr = *(mp **)v[j].buf;
+ mpmont_create(&mm, m);
+ r = mpmont_mexp(&mm, MP_NEW, f, n);
+ if (!MP_EQ(r, rr)) {
+ fputs("\n*** mexp failed\n", stderr);
+ fputs("m = ", stderr); mp_writefile(m, stderr, 10);
+ for (i = 0; i < n; i++) {
+ fprintf(stderr, "\ng_%u = ", i);
+ mp_writefile(f[i].base, stderr, 10);
+ fprintf(stderr, "\ne_%u = ", i);
+ mp_writefile(f[i].exp, stderr, 10);
+ }
+ fputs("\nr = ", stderr); mp_writefile(r, stderr, 10);
+ fputs("\nR = ", stderr); mp_writefile(rr, stderr, 10);
+ fputc('\n', stderr);
+ ok = 0;
+ }
+
+ for (i = 0; i < n; i++) {
+ MP_DROP(f[i].base);
+ MP_DROP(f[i].exp);
+ }
+ MP_DROP(m);
+ MP_DROP(r);
+ MP_DROP(rr);
+ mpmont_destroy(&mm);
+ assert(mparena_count(MPARENA_GLOBAL) == 0);
+ return (ok);
+}
+
+static int t1(dstr *v) { return verify(1, v); }
+static int t2(dstr *v) { return verify(2, v); }
+static int t3(dstr *v) { return verify(3, v); }
+static int t4(dstr *v) { return verify(4, v); }
+static int t5(dstr *v) { return verify(5, v); }
+
+static test_chunk tests[] = {
+ { "mexp-1", t1, { &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, 0 } },
+ { "mexp-2", t2, { &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, 0 } },
+ { "mexp-3", t3, { &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, 0 } },
+ { "mexp-4", t4, { &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, 0 } },
+ { "mexp-5", t5, { &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, &type_mp,
+ &type_mp, 0 } },
+ { 0, 0, { 0 } }
+};
+
+int main(int argc, char *argv[])
+{
+ sub_init();
+ test_run(argc, argv, tests, SRCDIR "/t/mpmont");
+ return (0);
+}
+
+#endif
+
+/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff