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/* 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.
*
*/
/* Implements ECC over Z/pZ for curve y^2 = x^3 + a*x + b
*
*/
#include "tomcrypt.h"
#ifdef LTC_MECC
/** Export raw public or private key (public keys = ANS X9.63 compressed or uncompressed; private keys = raw bytes)
@param out [out] destination of export
@param outlen [in/out] Length of destination and final output size
@param type PK_PRIVATE, PK_PUBLIC or PK_PUBLIC|PK_COMPRESSED
@param key Key to export
Return CRYPT_OK on success
*/
int ecc_export_raw(unsigned char *out, unsigned long *outlen, int type, ecc_key *key)
{
unsigned long size, ksize;
int err, compressed;
LTC_ARGCHK(key != NULL);
LTC_ARGCHK(out != NULL);
LTC_ARGCHK(outlen != NULL);
if (ltc_ecc_is_valid_idx(key->idx) == 0) {
return CRYPT_INVALID_ARG;
}
size = key->dp->size;
compressed = type & PK_COMPRESSED;
type &= ~PK_COMPRESSED;
if (type == PK_PUBLIC && compressed) {
if ((err = ltc_ecc_export_point(out, outlen, key->pubkey.x, key->pubkey.y, size, 1)) != CRYPT_OK) return err;
}
else if (type == PK_PUBLIC) {
if ((err = ltc_ecc_export_point(out, outlen, key->pubkey.x, key->pubkey.y, size, 0)) != CRYPT_OK) return err;
}
else if (type == PK_PRIVATE) {
if (key->type != PK_PRIVATE) return CRYPT_PK_TYPE_MISMATCH;
*outlen = size;
if (size > *outlen) return CRYPT_BUFFER_OVERFLOW;
if ((ksize = mp_unsigned_bin_size(key->k)) > size) return CRYPT_BUFFER_OVERFLOW;
/* pad and store k */
if ((err = mp_to_unsigned_bin(key->k, out + (size - ksize))) != CRYPT_OK) return err;
zeromem(out, size - ksize);
}
else {
return CRYPT_INVALID_ARG;
}
return CRYPT_OK;
}
#endif
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