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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 /* store in unsigned [big endian] format */ |
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18 int |
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19 mp_to_unsigned_bin (mp_int * a, unsigned char *b) |
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20 { |
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21 int x, res; |
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22 mp_int t; |
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23 |
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24 if ((res = mp_init_copy (&t, a)) != MP_OKAY) { |
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25 return res; |
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26 } |
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27 |
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28 x = 0; |
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29 while (mp_iszero (&t) == 0) { |
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30 #ifndef MP_8BIT |
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31 b[x++] = (unsigned char) (t.dp[0] & 255); |
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32 #else |
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33 b[x++] = (unsigned char) (t.dp[0] | ((t.dp[1] & 0x01) << 7)); |
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34 #endif |
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35 if ((res = mp_div_2d (&t, 8, &t, NULL)) != MP_OKAY) { |
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36 mp_clear (&t); |
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37 return res; |
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38 } |
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39 } |
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40 bn_reverse (b, x); |
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41 mp_clear (&t); |
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42 return MP_OKAY; |
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43 } |
