--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nss/lib/freebl/mpi/mplogic.c	Mon Jul 28 10:47:06 2014 +0200
@@ -0,0 +1,432 @@
+/*
+ *  mplogic.c
+ *
+ *  Bitwise logical operations on MPI values
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mpi-priv.h"
+#include "mplogic.h"
+
+/* {{{ Lookup table for population count */
+
+static unsigned char bitc[] = {
+   0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 
+   1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 
+   1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 
+   2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 
+   1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 
+   2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 
+   2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 
+   3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 
+   1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 
+   2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 
+   2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 
+   3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 
+   2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 
+   3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 
+   3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 
+   4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8
+};
+
+/* }}} */
+
+/*------------------------------------------------------------------------*/
+/*
+  mpl_not(a, b)    - compute b = ~a
+  mpl_and(a, b, c) - compute c = a & b
+  mpl_or(a, b, c)  - compute c = a | b
+  mpl_xor(a, b, c) - compute c = a ^ b
+ */
+
+/* {{{ mpl_not(a, b) */
+
+mp_err mpl_not(mp_int *a, mp_int *b)
+{
+  mp_err   res;
+  unsigned int      ix;
+
+  ARGCHK(a != NULL && b != NULL, MP_BADARG);
+
+  if((res = mp_copy(a, b)) != MP_OKAY)
+    return res;
+
+  /* This relies on the fact that the digit type is unsigned */
+  for(ix = 0; ix < USED(b); ix++) 
+    DIGIT(b, ix) = ~DIGIT(b, ix);
+
+  s_mp_clamp(b);
+
+  return MP_OKAY;
+
+} /* end mpl_not() */
+
+/* }}} */
+
+/* {{{ mpl_and(a, b, c) */
+
+mp_err mpl_and(mp_int *a, mp_int *b, mp_int *c)
+{
+  mp_int  *which, *other;
+  mp_err   res;
+  unsigned int      ix;
+
+  ARGCHK(a != NULL && b != NULL && c != NULL, MP_BADARG);
+
+  if(USED(a) <= USED(b)) {
+    which = a;
+    other = b;
+  } else {
+    which = b;
+    other = a;
+  }
+
+  if((res = mp_copy(which, c)) != MP_OKAY)
+    return res;
+
+  for(ix = 0; ix < USED(which); ix++)
+    DIGIT(c, ix) &= DIGIT(other, ix);
+
+  s_mp_clamp(c);
+
+  return MP_OKAY;
+
+} /* end mpl_and() */
+
+/* }}} */
+
+/* {{{ mpl_or(a, b, c) */
+
+mp_err mpl_or(mp_int *a, mp_int *b, mp_int *c)
+{
+  mp_int  *which, *other;
+  mp_err   res;
+  unsigned int      ix;
+
+  ARGCHK(a != NULL && b != NULL && c != NULL, MP_BADARG);
+
+  if(USED(a) >= USED(b)) {
+    which = a;
+    other = b;
+  } else {
+    which = b;
+    other = a;
+  }
+
+  if((res = mp_copy(which, c)) != MP_OKAY)
+    return res;
+
+  for(ix = 0; ix < USED(which); ix++)
+    DIGIT(c, ix) |= DIGIT(other, ix);
+
+  return MP_OKAY;
+
+} /* end mpl_or() */
+
+/* }}} */
+
+/* {{{ mpl_xor(a, b, c) */
+
+mp_err mpl_xor(mp_int *a, mp_int *b, mp_int *c)
+{
+  mp_int  *which, *other;
+  mp_err   res;
+  unsigned int      ix;
+
+  ARGCHK(a != NULL && b != NULL && c != NULL, MP_BADARG);
+
+  if(USED(a) >= USED(b)) {
+    which = a;
+    other = b;
+  } else {
+    which = b;
+    other = a;
+  }
+
+  if((res = mp_copy(which, c)) != MP_OKAY)
+    return res;
+
+  for(ix = 0; ix < USED(which); ix++)
+    DIGIT(c, ix) ^= DIGIT(other, ix);
+
+  s_mp_clamp(c);
+
+  return MP_OKAY;
+
+} /* end mpl_xor() */
+
+/* }}} */
+
+/*------------------------------------------------------------------------*/
+/*
+  mpl_rsh(a, b, d)     - b = a >> d
+  mpl_lsh(a, b, d)     - b = a << d
+ */
+
+/* {{{ mpl_rsh(a, b, d) */
+
+mp_err mpl_rsh(const mp_int *a, mp_int *b, mp_digit d)
+{
+  mp_err   res;
+
+  ARGCHK(a != NULL && b != NULL, MP_BADARG);
+
+  if((res = mp_copy(a, b)) != MP_OKAY)
+    return res;
+
+  s_mp_div_2d(b, d);
+
+  return MP_OKAY;
+
+} /* end mpl_rsh() */
+
+/* }}} */
+
+/* {{{ mpl_lsh(a, b, d) */
+
+mp_err mpl_lsh(const mp_int *a, mp_int *b, mp_digit d)
+{
+  mp_err   res;
+
+  ARGCHK(a != NULL && b != NULL, MP_BADARG);
+
+  if((res = mp_copy(a, b)) != MP_OKAY)
+    return res;
+
+  return s_mp_mul_2d(b, d);
+
+} /* end mpl_lsh() */
+
+/* }}} */
+
+/*------------------------------------------------------------------------*/
+/*
+  mpl_num_set(a, num)
+
+  Count the number of set bits in the binary representation of a.
+  Returns MP_OKAY and sets 'num' to be the number of such bits, if
+  possible.  If num is NULL, the result is thrown away, but it is
+  not considered an error.
+
+  mpl_num_clear() does basically the same thing for clear bits.
+ */
+
+/* {{{ mpl_num_set(a, num) */
+
+mp_err mpl_num_set(mp_int *a, int *num)
+{
+  unsigned int   ix;
+  int            db, nset = 0;
+  mp_digit       cur;
+  unsigned char  reg;
+
+  ARGCHK(a != NULL, MP_BADARG);
+
+  for(ix = 0; ix < USED(a); ix++) {
+    cur = DIGIT(a, ix);
+    
+    for(db = 0; db < sizeof(mp_digit); db++) {
+      reg = (unsigned char)(cur >> (CHAR_BIT * db));
+
+      nset += bitc[reg];
+    }
+  }
+
+  if(num)
+    *num = nset;
+
+  return MP_OKAY;
+
+} /* end mpl_num_set() */
+
+/* }}} */
+
+/* {{{ mpl_num_clear(a, num) */
+
+mp_err mpl_num_clear(mp_int *a, int *num)
+{
+  unsigned int   ix;
+  int            db, nset = 0;
+  mp_digit       cur;
+  unsigned char  reg;
+
+  ARGCHK(a != NULL, MP_BADARG);
+
+  for(ix = 0; ix < USED(a); ix++) {
+    cur = DIGIT(a, ix);
+    
+    for(db = 0; db < sizeof(mp_digit); db++) {
+      reg = (unsigned char)(cur >> (CHAR_BIT * db));
+
+      nset += bitc[UCHAR_MAX - reg];
+    }
+  }
+
+  if(num)
+    *num = nset;
+
+  return MP_OKAY;
+
+
+} /* end mpl_num_clear() */
+
+/* }}} */
+
+/*------------------------------------------------------------------------*/
+/*
+  mpl_parity(a)
+
+  Determines the bitwise parity of the value given.  Returns MP_EVEN
+  if an even number of digits are set, MP_ODD if an odd number are
+  set.
+ */
+
+/* {{{ mpl_parity(a) */
+
+mp_err mpl_parity(mp_int *a)
+{
+  unsigned int ix;
+  int      par = 0;
+  mp_digit cur;
+
+  ARGCHK(a != NULL, MP_BADARG);
+
+  for(ix = 0; ix < USED(a); ix++) {
+    int   shft = (sizeof(mp_digit) * CHAR_BIT) / 2;
+
+    cur = DIGIT(a, ix);
+
+    /* Compute parity for current digit */
+    while(shft != 0) {
+      cur ^= (cur >> shft);
+      shft >>= 1;
+    }
+    cur &= 1;
+
+    /* XOR with running parity so far   */
+    par ^= cur;
+  }
+
+  if(par)
+    return MP_ODD;
+  else
+    return MP_EVEN;
+
+} /* end mpl_parity() */
+
+/* }}} */
+
+/*
+  mpl_set_bit
+
+  Returns MP_OKAY or some error code.
+  Grows a if needed to set a bit to 1.
+ */
+mp_err mpl_set_bit(mp_int *a, mp_size bitNum, mp_size value)
+{
+  mp_size      ix;
+  mp_err       rv;
+  mp_digit     mask;
+
+  ARGCHK(a != NULL, MP_BADARG);
+
+  ix = bitNum / MP_DIGIT_BIT;
+  if (ix + 1 > MP_USED(a)) {
+    rv = s_mp_pad(a, ix + 1);
+    if (rv != MP_OKAY)
+      return rv;
+  }
+
+  bitNum = bitNum % MP_DIGIT_BIT;
+  mask = (mp_digit)1 << bitNum;
+  if (value)
+    MP_DIGIT(a,ix) |= mask;
+  else
+    MP_DIGIT(a,ix) &= ~mask;
+  s_mp_clamp(a);
+  return MP_OKAY;
+}
+
+/*
+  mpl_get_bit
+
+  returns 0 or 1 or some (negative) error code.
+ */
+mp_err mpl_get_bit(const mp_int *a, mp_size bitNum)
+{
+  mp_size      bit, ix;
+  mp_err       rv;
+
+  ARGCHK(a != NULL, MP_BADARG);
+
+  ix = bitNum / MP_DIGIT_BIT;
+  ARGCHK(ix <= MP_USED(a) - 1, MP_RANGE);
+
+  bit   = bitNum % MP_DIGIT_BIT;
+  rv = (mp_err)(MP_DIGIT(a, ix) >> bit) & 1;
+  return rv;
+}
+
+/*
+  mpl_get_bits
+  - Extracts numBits bits from a, where the least significant extracted bit
+  is bit lsbNum.  Returns a negative value if error occurs.
+  - Because sign bit is used to indicate error, maximum number of bits to 
+  be returned is the lesser of (a) the number of bits in an mp_digit, or
+  (b) one less than the number of bits in an mp_err.
+  - lsbNum + numbits can be greater than the number of significant bits in
+  integer a, as long as bit lsbNum is in the high order digit of a.
+ */
+mp_err mpl_get_bits(const mp_int *a, mp_size lsbNum, mp_size numBits) 
+{
+  mp_size    rshift = (lsbNum % MP_DIGIT_BIT);
+  mp_size    lsWndx = (lsbNum / MP_DIGIT_BIT);
+  mp_digit * digit  = MP_DIGITS(a) + lsWndx;
+  mp_digit   mask   = ((1 << numBits) - 1);
+
+  ARGCHK(numBits < CHAR_BIT * sizeof mask, MP_BADARG);
+  ARGCHK(MP_HOWMANY(lsbNum, MP_DIGIT_BIT) <= MP_USED(a), MP_RANGE);
+
+  if ((numBits + lsbNum % MP_DIGIT_BIT <= MP_DIGIT_BIT) ||
+      (lsWndx + 1 >= MP_USED(a))) {
+    mask &= (digit[0] >> rshift);
+  } else {
+    mask &= ((digit[0] >> rshift) | (digit[1] << (MP_DIGIT_BIT - rshift)));
+  }
+  return (mp_err)mask;
+}
+
+/*
+  mpl_significant_bits
+  returns number of significnant bits in abs(a).
+  returns 1 if value is zero.
+ */
+mp_err mpl_significant_bits(const mp_int *a)
+{
+  mp_err bits 	= 0;
+  int    ix;
+
+  ARGCHK(a != NULL, MP_BADARG);
+
+  ix = MP_USED(a);
+  for (ix = MP_USED(a); ix > 0; ) {
+    mp_digit d;
+    d = MP_DIGIT(a, --ix);
+    if (d) {
+      while (d) {
+	++bits;
+	d >>= 1;
+      }
+      break;
+    }
+  }
+  bits += ix * MP_DIGIT_BIT;
+  if (!bits)
+    bits = 1;
+  return bits;
+}
+
+/*------------------------------------------------------------------------*/
+/* HERE THERE BE DRAGONS                                                  */