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1 /* LibTomMath, multiple-precision integer library -- Tom St Denis |
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2 * |
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3 * LibTomMath is a library that provides multiple-precision |
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4 * integer arithmetic as well as number theoretic functionality. |
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5 * |
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6 * The library was designed directly after the MPI library by |
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7 * Michael Fromberger but has been written from scratch with |
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8 * additional optimizations in place. |
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9 * |
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10 * The library is free for all purposes without any express |
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11 * guarantee it works. |
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12 * |
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13 * Tom St Denis, [email protected], http://math.libtomcrypt.org |
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14 */ |
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15 #include <tommath.h> |
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16 |
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17 /* computes b = a*a */ |
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18 int |
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19 mp_sqr (mp_int * a, mp_int * b) |
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20 { |
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21 int res; |
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22 |
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23 /* use Toom-Cook? */ |
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24 if (a->used >= TOOM_SQR_CUTOFF) { |
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25 res = mp_toom_sqr(a, b); |
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26 /* Karatsuba? */ |
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27 } else if (a->used >= KARATSUBA_SQR_CUTOFF) { |
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28 res = mp_karatsuba_sqr (a, b); |
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29 } else { |
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30 /* can we use the fast comba multiplier? */ |
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31 if ((a->used * 2 + 1) < MP_WARRAY && |
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32 a->used < |
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33 (1 << (sizeof(mp_word) * CHAR_BIT - 2*DIGIT_BIT - 1))) { |
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34 res = fast_s_mp_sqr (a, b); |
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35 } else { |
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36 res = s_mp_sqr (a, b); |
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37 } |
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38 } |
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39 b->sign = MP_ZPOS; |
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40 return res; |
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41 } |
