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1 #include <tommath.h> |
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2 #ifdef BN_MP_REDUCE_IS_2K_L_C |
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3 /* LibTomMath, multiple-precision integer library -- Tom St Denis |
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4 * |
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5 * LibTomMath is a library that provides multiple-precision |
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6 * integer arithmetic as well as number theoretic functionality. |
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7 * |
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8 * The library was designed directly after the MPI library by |
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9 * Michael Fromberger but has been written from scratch with |
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10 * additional optimizations in place. |
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11 * |
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12 * The library is free for all purposes without any express |
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13 * guarantee it works. |
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14 * |
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15 * Tom St Denis, [email protected], http://math.libtomcrypt.com |
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16 */ |
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17 |
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18 /* determines if reduce_2k_l can be used */ |
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19 int mp_reduce_is_2k_l(mp_int *a) |
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20 { |
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21 int ix, iy; |
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22 |
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23 if (a->used == 0) { |
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24 return MP_NO; |
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25 } else if (a->used == 1) { |
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26 return MP_YES; |
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27 } else if (a->used > 1) { |
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28 /* if more than half of the digits are -1 we're sold */ |
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29 for (iy = ix = 0; ix < a->used; ix++) { |
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30 if (a->dp[ix] == MP_MASK) { |
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31 ++iy; |
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32 } |
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33 } |
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34 return (iy >= (a->used/2)) ? MP_YES : MP_NO; |
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35 |
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36 } |
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37 return MP_NO; |
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38 } |
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39 |
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40 #endif |
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41 |
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42 /* $Source: /cvs/libtom/libtommath/bn_mp_reduce_is_2k_l.c,v $ */ |
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43 /* $Revision: 1.3 $ */ |
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44 /* $Date: 2006/03/31 14:18:44 $ */ |
