Support for conversions between MPs and C integers.
authormdw <mdw>
Thu, 25 Nov 1999 11:38:33 +0000 (11:38 +0000)
committermdw <mdw>
Thu, 25 Nov 1999 11:38:33 +0000 (11:38 +0000)
Makefile.m4
mpint.c [new file with mode: 0644]
mpint.h [new file with mode: 0644]
tests/mpint [new file with mode: 0644]

index f5461b3..8cf9edc 100644 (file)
@@ -1,6 +1,6 @@
 ## -*-makefile-*-
 ##
-## $Id: Makefile.m4,v 1.16 1999/11/22 20:51:33 mdw Exp $
+## $Id: Makefile.m4,v 1.17 1999/11/25 11:38:31 mdw Exp $
 ##
 ## Makefile for Catacomb
 ##
@@ -29,6 +29,9 @@
 ##----- Revision history ----------------------------------------------------
 ##
 ## $Log: Makefile.m4,v $
+## Revision 1.17  1999/11/25 11:38:31  mdw
+## Support for conversions between MPs and C integers.
+##
 ## Revision 1.16  1999/11/22 20:51:33  mdw
 ## Add yet more source files.
 ##
@@ -151,7 +154,8 @@ pkginclude_HEADERS = \
        rc4.h \
        rand.h noise.h \
        key.h \
-       mpx.h mpw.h mpscan.h mparena.h mp.h mptext.h mpmont.h mpcrt.h \
+       mpx.h mpw.h mpscan.h mparena.h mp.h mptext.h mpint.h \
+       mpmont.h mpcrt.h \
        ptab.h pgen.h rabin.h \
        dsa.h dh.h \
        allwithsuffix(`ciphers', `cipher_modes', `.h') \
@@ -166,6 +170,7 @@ libcatacomb_la_SOURCES = \
        mpx.c mpscan.c mparena.c \
        mp-misc.c mp-mem.c mp-const.c mp-io.c mp-arith.c mp-test.c \
        mp-gcd.c mp-jacobi.c \
+       mpint.c \
        mptext.c mptext-file.c mptext-string.c mptext-dstr.c \
        mpmont.c mpmont-mexp.c \
        mpcrt.c \
@@ -233,6 +238,7 @@ CTESTRIG(mptext)
 CTESTRIG(mp-arith)
 CTESTRIG(mp-gcd)
 CTESTRIG(mp-jacobi)
+CTESTRIG(mpint)
 CTESTRIG(mpmont)
 CTESTRIG(mpmont-mexp)
 CTESTRIG(mpcrt)
diff --git a/mpint.c b/mpint.c
new file mode 100644 (file)
index 0000000..de3ed8b
--- /dev/null
+++ b/mpint.c
@@ -0,0 +1,181 @@
+/* -*-c-*-
+ *
+ * $Id: mpint.c,v 1.1 1999/11/25 11:38:31 mdw Exp $
+ *
+ * Conversion between MPs and standard C integers
+ *
+ * (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.
+ */
+
+/*----- Revision history --------------------------------------------------* 
+ *
+ * $Log: mpint.c,v $
+ * Revision 1.1  1999/11/25 11:38:31  mdw
+ * Support for conversions between MPs and C integers.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include "mpint.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- Conversion from C integers --- */
+
+#define FROM(name, type)                                               \
+  mp *mp_from##name(mp *d, type i) {                                   \
+    MP_FROMINT(d, type, i);                                            \
+    return (d);                                                                \
+  }
+
+FROM(short, short)
+FROM(ushort, unsigned short)
+FROM(int, int)
+FROM(uint, unsigned)
+FROM(long, long)
+FROM(ulong, unsigned long)
+
+#undef FROM
+
+/* --- Conversion to C integers --- */
+
+#define TO(name, type, max)                                            \
+  type mp_to##name(const mp *m)                                                \
+  {                                                                    \
+    type i;                                                            \
+    MP_TOINT(m, type, max, i);                                         \
+    return (i);                                                                \
+  }
+
+TO(short, short, SHRT_MAX)
+TO(ushort, unsigned short, USHRT_MAX)
+TO(int, int, INT_MAX)
+TO(uint, unsigned, UINT_MAX)
+TO(long, long, LONG_MAX)
+TO(ulong, unsigned long, ULONG_MAX)
+
+#undef TO
+
+/*----- Test rig ----------------------------------------------------------*/
+
+#ifdef TEST_RIG
+
+#include <mLib/testrig.h>
+
+static int fromuint(dstr *v)
+{
+  unsigned i = *(unsigned *)v[0].buf;
+  mp *m = *(mp **)v[1].buf;
+  mp *d = mp_fromuint(MP_NEW, i);
+  int ok = 1;
+
+  if (MP_CMP(d, !=, m)) {
+    fputs("\n*** fromint failed.\n", stderr);
+    fprintf(stderr, "i = %u", i);
+    fputs("\nexpect = ", stderr); mp_writefile(m, stderr, 10);
+    fputs("\nresult = ", stderr); mp_writefile(d, stderr, 10);
+    fputc('\n', stderr);
+    ok = 0;
+  }
+
+  mp_drop(m);
+  mp_drop(d);
+  return (ok);
+}
+
+static int fromint(dstr *v)
+{
+  int i = *(int *)v[0].buf;
+  mp *m = *(mp **)v[1].buf;
+  mp *d = mp_fromint(MP_NEW, i);
+  int ok = 1;
+
+  if (MP_CMP(d, !=, m)) {
+    fputs("\n*** fromint failed.\n", stderr);
+    fprintf(stderr, "i = %i", i);
+    fputs("\nexpect = ", stderr); mp_writefile(m, stderr, 10);
+    fputs("\nresult = ", stderr); mp_writefile(d, stderr, 10);
+    fputc('\n', stderr);
+    ok = 0;
+  }
+
+  mp_drop(m);
+  mp_drop(d);
+  return (ok);
+}
+
+static int touint(dstr *v)
+{
+  mp *m = *(mp **)v[0].buf;
+  unsigned i = *(unsigned *)v[1].buf;
+  unsigned j = mp_touint(m);
+  int ok = 1;
+
+  if (i != j) {
+    fputs("\n*** touint failed.\n", stderr);
+    fputs("m = ", stderr); mp_writefile(m, stderr, 10);
+    fprintf(stderr, "\nexpect = %u; result = %u\n", i, j);
+    ok = 0;
+  }
+
+  mp_drop(m);
+  return (ok);
+}
+
+static int toint(dstr *v)
+{
+  mp *m = *(mp **)v[0].buf;
+  int i = *(int *)v[1].buf;
+  int j = mp_toint(m);
+  int ok = 1;
+
+  if (i != j) {
+    fputs("\n*** toint failed.\n", stderr);
+    fputs("m = ", stderr); mp_writefile(m, stderr, 10);
+    fprintf(stderr, "\nexpect = %i; result = %i\n", i, j);
+    ok = 0;
+  }
+
+  mp_drop(m);
+  return (ok);
+}
+
+static test_chunk tests[] = {
+  { "fromuint", fromuint, { &type_int, &type_mp, 0 } },
+  { "fromint", fromint, { &type_int, &type_mp, 0 } },
+  { "touint", touint, { &type_mp, &type_int, 0 } },
+  { "toint", toint, { &type_mp, &type_int, 0 } },
+  { 0, 0, { 0 } }
+};
+
+int main(int argc, char *argv[])
+{
+  sub_init();
+  test_run(argc, argv, tests, SRCDIR "/tests/mpint");
+  return (0);
+}
+
+#endif
+
+/*----- That's all, folks -------------------------------------------------*/
diff --git a/mpint.h b/mpint.h
new file mode 100644 (file)
index 0000000..733292b
--- /dev/null
+++ b/mpint.h
@@ -0,0 +1,207 @@
+/* -*-c-*-
+ *
+ * $Id: mpint.h,v 1.1 1999/11/25 11:38:31 mdw Exp $
+ *
+ * Conversion between MPs and standard C integers
+ *
+ * (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.
+ */
+
+/*----- Revision history --------------------------------------------------* 
+ *
+ * $Log: mpint.h,v $
+ * Revision 1.1  1999/11/25 11:38:31  mdw
+ * Support for conversions between MPs and C integers.
+ *
+ */
+
+#ifndef MPINT_H
+#define MPINT_H
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <limits.h>
+
+#ifndef MP_H
+#  include "mp.h"
+#endif
+
+/*----- Generic translation macros ----------------------------------------*/
+
+/* --- @MP_FROMINT@ --- *
+ *
+ * Arguments:  @d@ = destination multiprecision integer
+ *             @type@ = type of integer which @i@ is
+ *             @i@ = a standard C integer
+ *
+ * Use:                Stores the value of @i@ in @d@.  This macro is actually
+ *             rather subtle in places.  Be careful what you change.
+ */
+
+#define MP_FROMINT(d, type, i) do {                                    \
+  type _i = (i);                                                       \
+  size_t _o = 0;                                                       \
+  mp *_d = (d);                                                                \
+  size_t _sz = 4;                                                      \
+                                                                       \
+  MP_MODIFY(_d, _sz);                                                  \
+  _d->f &= ~(MP_NEG | MP_UNDEF);                                       \
+                                                                       \
+  /* --- Set the sign on the MP --- *                                  \
+   *                                                                   \
+   * If the input integer is *not* negative, then negate it.  This     \
+   * fixes a problem with two's complement machines where the most     \
+   * negative value actually has larger magnitude than the most                \
+   * positive, and hence -TYPE_MIN == TYPE_MIN but TYPE_MIN != 0.  If  \
+   * all the work is carried out on negative numbers there isn't a     \
+   * problem.                                                          \
+   */                                                                  \
+                                                                       \
+  if (_i >= 0)                                                         \
+    _i = -_i;                                                          \
+  else                                                                 \
+    _d->f |= MP_NEG;                                                   \
+                                                                       \
+  while (_i) {                                                         \
+    if (_o == _sz) {                                                   \
+      _sz <<= 1;                                                       \
+      MP_ENSURE(_d, _sz);                                              \
+    }                                                                  \
+    _d->v[_o++] = MPW(-_i);                                            \
+                                                                       \
+    /* --- More subtlety --- *                                         \
+     *                                                                 \
+     * Ideally, I'd like to just shift @i@ right by @MPW_BITS@.  But I \
+     * can't, because that might be more than I'm allowed.  I can't    \
+     * divide by @MPW_MAX + 1@ because that might turn out to be zero  \
+     * in my current type, and besides which it's unsigned which messes        \
+     * up all of my negative arithmetic.  So do an explicit test here. \
+     */                                                                        \
+                                                                       \
+    if (_i > -MPW_MAX)                                                 \
+      break;                                                           \
+    else                                                               \
+      _i /= (type)MPW_MAX + 1;                                         \
+  }                                                                    \
+  _d->vl = _d->v + _o;                                                 \
+  (d) = _d;                                                            \
+} while (0)
+
+/* --- @MP_TOINT@ --- *
+ *
+ * Arguments:  @m@ = a multiprecision integer
+ *             @type@ = the type of @i@
+ *             @max@ = the largest value @i@ can represent
+ *             @i@ = an integer variable
+ *
+ * Use:                Stores the value of a multiprecision integer in a standard C
+ *             integer.  If the value won't fit, the behaviour is determined
+ *             by the type of @i@: if @i@ is unsigned, the value of the
+ *             multiprecision integer modulo @max + 1@ is stored; if @i@ is
+ *             signed, the behaviour is undefined.
+ *
+ *             If you don't want to be bitten by these sorts of things, keep
+ *             copies of @INT_MAX@ or whatever is appropriate in
+ *             multiprecision form and compare before conversion.
+ */
+
+#define MP_TOINT(m, type, max, i) do {                                 \
+  type _i = 0;                                                         \
+  type _max = (max);                                                   \
+  unsigned _s = 0;                                                     \
+  const mp *_m = (m);                                                  \
+  const mpw *_v = _m->v, *_vl = _m->vl;                                        \
+                                                                       \
+  /* --- Do all the arithmetic in negative numbers --- */              \
+                                                                       \
+  while (_v < _vl && _max > 0) {                                       \
+    _i -= *_v << _s;                                                   \
+    _s += MPW_BITS;                                                    \
+    _v++;                                                              \
+    _max /= (mpd)MPW_MAX + 1;                                          \
+  }                                                                    \
+  if (!(_m->f & MP_NEG))                                               \
+    _i = -_i;                                                          \
+  (i) = _i;                                                            \
+} while (0)
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @mp_fromINT@ --- *
+ *
+ * Arguments:  @mp *d@ = pointer to destination multiprecision integer
+ *             @INT i@ = standard C integer to convert
+ *
+ * Returns:    The resulting multiprecision integer.
+ *
+ * Use:                Converts a standard C integer to a multiprecision integer.
+ */
+
+#define mp_fromINT(name, type)                                         \
+  extern mp *mp_from##name(mp */*d*/, type /*i*/)
+
+mp_fromINT(short, short);
+mp_fromINT(ushort, unsigned short);
+mp_fromINT(int, int);
+mp_fromINT(uint, unsigned);
+mp_fromINT(long, long);
+mp_fromINT(ulong, unsigned long);
+
+#undef mp_fromINT
+
+/* --- @mp_toINT@ --- *
+ *
+ * Arguments:  @const mp *m@ = pointer to a multiprecision integer
+ *
+ * Returns:    The value of the integer @m@ as a C integer.
+ *
+ * Use:                Converts a multiprecision integer to a standard C integer.
+ *             If the value of the multiprecision integer cannot be
+ *             represented in the return type, and the return type is
+ *             unsigned, it is reduced modulo @TYPE_MAX + 1@; if the return
+ *             type is signed, the behaviour is undefined.
+ */
+
+#define mp_toINT(name, type)                                           \
+  extern type mp_to##name(const mp */*m*/);
+
+mp_toINT(short, short);
+mp_toINT(ushort, unsigned short);
+mp_toINT(int, int);
+mp_toINT(uint, unsigned);
+mp_toINT(long, long);
+mp_toINT(ulong, unsigned long);
+
+#undef mp_toINT
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+  }
+#endif
+
+#endif
diff --git a/tests/mpint b/tests/mpint
new file mode 100644 (file)
index 0000000..d0c9667
--- /dev/null
@@ -0,0 +1,39 @@
+# Test vectors for conversion between MP ints and C ints
+#
+# $Id: mpint,v 1.1 1999/11/25 11:38:33 mdw Exp $
+
+# The tests look messy because I'm fighting with atoi here as well as the
+# integer conversion routines I'm trying to test.
+
+fromuint {
+  0 0;
+  1 1;
+  -5 0xfffffffb;
+  0x7fffffff 0x7fffffff;
+  -0x80000000 0x80000000;              # Bastard torture test
+}
+
+fromint {
+  0 0;
+  1 1;
+  -5 -5;
+  0x7fffffff 0x7fffffff;
+  -0x80000000 -0x80000000;             # Bastard torture test
+}
+
+touint {
+  0 0;
+  1 1;
+  -5 -5;
+  0x7fffffff 0x7fffffff;
+  0x80000000 -0x80000000;              # Bastard torture test
+}
+
+toint {
+  0 0;
+  1 1;
+  -5 -5;
+  0x7fffffff 0x7fffffff;
+  -0x80000000 -0x80000000;             # Bastard torture test
+}
+