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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 /* AND two ints together */ |
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18 int |
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19 mp_and (mp_int * a, mp_int * b, mp_int * c) |
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20 { |
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21 int res, ix, px; |
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22 mp_int t, *x; |
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23 |
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24 if (a->used > b->used) { |
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25 if ((res = mp_init_copy (&t, a)) != MP_OKAY) { |
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26 return res; |
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27 } |
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28 px = b->used; |
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29 x = b; |
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30 } else { |
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31 if ((res = mp_init_copy (&t, b)) != MP_OKAY) { |
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32 return res; |
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33 } |
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34 px = a->used; |
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35 x = a; |
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36 } |
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37 |
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38 for (ix = 0; ix < px; ix++) { |
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39 t.dp[ix] &= x->dp[ix]; |
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40 } |
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41 |
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42 /* zero digits above the last from the smallest mp_int */ |
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43 for (; ix < t.used; ix++) { |
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44 t.dp[ix] = 0; |
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45 } |
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46 |
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47 mp_clamp (&t); |
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48 mp_exch (c, &t); |
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49 mp_clear (&t); |
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50 return MP_OKAY; |
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51 } |
