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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.com |
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10 */ |
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11 |
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12 /* Implements ECC over Z/pZ for curve y^2 = x^3 - 3x + b |
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13 * |
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14 * All curves taken from NIST recommendation paper of July 1999 |
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15 * Available at http://csrc.nist.gov/cryptval/dss.htm |
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16 */ |
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17 #include "tomcrypt.h" |
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18 |
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19 /** |
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20 @file ecc_export.c |
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21 ECC Crypto, Tom St Denis |
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22 */ |
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23 |
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24 #ifdef MECC |
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25 |
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26 /** |
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27 Export an ECC key as a binary packet |
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28 @param out [out] Destination for the key |
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29 @param outlen [in/out] Max size and resulting size of the exported key |
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30 @param type The type of key you want to export (PK_PRIVATE or PK_PUBLIC) |
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31 @param key The key to export |
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32 @return CRYPT_OK if successful |
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33 */ |
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34 int ecc_export(unsigned char *out, unsigned long *outlen, int type, ecc_key *key) |
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35 { |
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36 int err; |
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37 unsigned char flags[1]; |
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38 unsigned long key_size; |
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39 |
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40 LTC_ARGCHK(out != NULL); |
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41 LTC_ARGCHK(outlen != NULL); |
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42 LTC_ARGCHK(key != NULL); |
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43 |
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44 /* type valid? */ |
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45 if (key->type != PK_PRIVATE && type == PK_PRIVATE) { |
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46 return CRYPT_PK_TYPE_MISMATCH; |
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47 } |
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48 |
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49 if (ltc_ecc_is_valid_idx(key->idx) == 0) { |
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50 return CRYPT_INVALID_ARG; |
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51 } |
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52 |
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53 /* we store the NIST byte size */ |
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54 key_size = key->dp->size; |
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55 |
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56 if (type == PK_PRIVATE) { |
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57 flags[0] = 1; |
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58 err = der_encode_sequence_multi(out, outlen, |
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59 LTC_ASN1_BIT_STRING, 1UL, flags, |
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60 LTC_ASN1_SHORT_INTEGER, 1UL, &key_size, |
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61 LTC_ASN1_INTEGER, 1UL, key->pubkey.x, |
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62 LTC_ASN1_INTEGER, 1UL, key->pubkey.y, |
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63 LTC_ASN1_INTEGER, 1UL, key->k, |
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64 LTC_ASN1_EOL, 0UL, NULL); |
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65 } else { |
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66 flags[0] = 0; |
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67 err = der_encode_sequence_multi(out, outlen, |
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68 LTC_ASN1_BIT_STRING, 1UL, flags, |
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69 LTC_ASN1_SHORT_INTEGER, 1UL, &key_size, |
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70 LTC_ASN1_INTEGER, 1UL, key->pubkey.x, |
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71 LTC_ASN1_INTEGER, 1UL, key->pubkey.y, |
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72 LTC_ASN1_EOL, 0UL, NULL); |
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73 } |
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74 |
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75 return err; |
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76 } |
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77 |
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78 #endif |
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79 /* $Source: /cvs/libtom/libtomcrypt/src/pk/ecc/ecc_export.c,v $ */ |
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80 /* $Revision: 1.4 $ */ |
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81 /* $Date: 2006/11/21 00:10:18 $ */ |
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82 |