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1 #include <tommath_private.h> |
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2 #ifdef BN_MP_IMPORT_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://libtom.org |
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16 */ |
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17 |
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18 /* based on gmp's mpz_import. |
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19 * see http://gmplib.org/manual/Integer-Import-and-Export.html |
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20 */ |
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21 int mp_import(mp_int* rop, size_t count, int order, size_t size, |
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22 int endian, size_t nails, const void* op) { |
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23 int result; |
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24 size_t odd_nails, nail_bytes, i, j; |
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25 unsigned char odd_nail_mask; |
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26 |
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27 mp_zero(rop); |
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28 |
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29 if (endian == 0) { |
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30 union { |
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31 unsigned int i; |
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32 char c[4]; |
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33 } lint; |
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34 lint.i = 0x01020304; |
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35 |
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36 endian = (lint.c[0] == 4) ? -1 : 1; |
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37 } |
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38 |
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39 odd_nails = (nails % 8); |
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40 odd_nail_mask = 0xff; |
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41 for (i = 0; i < odd_nails; ++i) { |
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42 odd_nail_mask ^= (1 << (7 - i)); |
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43 } |
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44 nail_bytes = nails / 8; |
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45 |
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46 for (i = 0; i < count; ++i) { |
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47 for (j = 0; j < (size - nail_bytes); ++j) { |
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48 unsigned char byte = *( |
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49 (unsigned char*)op + |
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50 (((order == 1) ? i : ((count - 1) - i)) * size) + |
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51 ((endian == 1) ? (j + nail_bytes) : (((size - 1) - j) - nail_bytes)) |
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52 ); |
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53 |
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54 if ( |
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55 (result = mp_mul_2d(rop, ((j == 0) ? (8 - odd_nails) : 8), rop)) != MP_OKAY) { |
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56 return result; |
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57 } |
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58 |
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59 rop->dp[0] |= (j == 0) ? (byte & odd_nail_mask) : byte; |
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60 rop->used += 1; |
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61 } |
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62 } |
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63 |
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64 mp_clamp(rop); |
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65 |
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66 return MP_OKAY; |
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67 } |
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68 |
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69 #endif |
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70 |
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71 /* $Source$ */ |
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72 /* $Revision$ */ |
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73 /* $Date$ */ |
