/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com *//* Implements ECC over Z/pZ for curve y^2 = x^3 - 3x + b * * All curves taken from NIST recommendation paper of July 1999 * Available at http://csrc.nist.gov/cryptval/dss.htm */#include "tomcrypt.h"/**  @file ecc_export.c  ECC Crypto, Tom St Denis*/  #ifdef MECC/**  Export an ECC key as a binary packet  @param out     [out] Destination for the key  @param outlen  [in/out] Max size and resulting size of the exported key  @param type    The type of key you want to export (PK_PRIVATE or PK_PUBLIC)  @param key     The key to export  @return CRYPT_OK if successful*/int ecc_export(unsigned char *out, unsigned long *outlen, int type, ecc_key *key){   int           err;   unsigned char flags[1];   unsigned long key_size;   LTC_ARGCHK(out    != NULL);   LTC_ARGCHK(outlen != NULL);   LTC_ARGCHK(key    != NULL);      /* type valid? */   if (key->type != PK_PRIVATE && type == PK_PRIVATE) {      return CRYPT_PK_TYPE_MISMATCH;   }   if (ltc_ecc_is_valid_idx(key->idx) == 0) {      return CRYPT_INVALID_ARG;   }   /* we store the NIST byte size */   key_size = key->dp->size;   if (type == PK_PRIVATE) {       flags[0] = 1;       err = der_encode_sequence_multi(out, outlen,                                 LTC_ASN1_BIT_STRING,      1UL, flags,                                 LTC_ASN1_SHORT_INTEGER,   1UL, &key_size,                                 LTC_ASN1_INTEGER,         1UL, key->pubkey.x,                                 LTC_ASN1_INTEGER,         1UL, key->pubkey.y,                                 LTC_ASN1_INTEGER,         1UL, key->k,                                 LTC_ASN1_EOL,             0UL, NULL);   } else {       flags[0] = 0;       err = der_encode_sequence_multi(out, outlen,                                 LTC_ASN1_BIT_STRING,      1UL, flags,                                 LTC_ASN1_SHORT_INTEGER,   1UL, &key_size,                                 LTC_ASN1_INTEGER,         1UL, key->pubkey.x,                                 LTC_ASN1_INTEGER,         1UL, key->pubkey.y,                                 LTC_ASN1_EOL,             0UL, NULL);   }   return err;}#endif/* $Source: /cvs/libtom/libtomcrypt/src/pk/ecc/ecc_export.c,v $ *//* $Revision: 1.4 $ *//* $Date: 2006/11/21 00:10:18 $ */