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1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
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2 * |
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3 * LibTomCrypt is a library that provides various cryptographic |
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4 * algorithms in a highly modular and flexible manner. |
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5 * |
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6 * The library is free for all purposes without any express |
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7 * guarantee it works. |
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8 * |
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9 * Tom St Denis, [email protected], http://libtomcrypt.org |
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10 */ |
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11 #include "mycrypt.h" |
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12 |
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13 #ifdef MPI |
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14 |
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15 struct rng_data { |
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16 prng_state *prng; |
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17 int wprng; |
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18 }; |
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19 |
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20 static int rand_prime_helper(unsigned char *dst, int len, void *dat) |
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21 { |
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22 return (int)prng_descriptor[((struct rng_data *)dat)->wprng].read(dst, len, ((struct rng_data *)dat)->prng); |
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23 } |
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24 |
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25 int rand_prime(mp_int *N, long len, prng_state *prng, int wprng) |
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26 { |
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27 struct rng_data rng; |
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28 int type, err; |
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29 |
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30 _ARGCHK(N != NULL); |
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31 |
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32 /* allow sizes between 2 and 256 bytes for a prime size */ |
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33 if (len < 16 || len > 4096) { |
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34 return CRYPT_INVALID_PRIME_SIZE; |
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35 } |
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36 |
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37 /* valid PRNG? Better be! */ |
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38 if ((err = prng_is_valid(wprng)) != CRYPT_OK) { |
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39 return err; |
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40 } |
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41 |
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42 /* setup our callback data, then world domination! */ |
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43 rng.prng = prng; |
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44 rng.wprng = wprng; |
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45 |
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46 /* get type */ |
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47 if (len < 0) { |
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48 type = LTM_PRIME_BBS; |
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49 len = -len; |
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50 } else { |
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51 type = 0; |
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52 } |
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53 |
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54 /* New prime generation makes the code even more cryptoish-insane. Do you know what this means!!! |
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55 -- Gir: Yeah, oh wait, er, no. |
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56 */ |
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57 if ((err = mp_prime_random_ex(N, mp_prime_rabin_miller_trials(len), len, type, rand_prime_helper, &rng)) != MP_OKAY) { |
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58 return mpi_to_ltc_error(err); |
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59 } |
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60 |
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61 return CRYPT_OK; |
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62 } |
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63 |
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64 #endif |
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65 |
