Merge branch 'miko-ecc_ansi_x963_export-fix' into develop

This closes #58 and closes #99
This commit is contained in:
Steffen Jaeckel 2016-01-14 21:33:04 +01:00
commit f108863dc3

View File

@ -19,7 +19,7 @@
/**
@file ecc_ansi_x963_export.c
ECC Crypto, Tom St Denis
*/
*/
#ifdef LTC_MECC
@ -32,33 +32,40 @@
int ecc_ansi_x963_export(ecc_key *key, unsigned char *out, unsigned long *outlen)
{
unsigned char buf[ECC_BUF_SIZE];
unsigned long numlen;
unsigned long numlen, xlen, ylen;
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;
}
numlen = key->dp->size;
xlen = mp_unsigned_bin_size(key->pubkey.x);
ylen = mp_unsigned_bin_size(key->pubkey.y);
if (xlen > numlen || ylen > numlen || sizeof(buf) < numlen) {
return CRYPT_BUFFER_OVERFLOW;
}
if (*outlen < (1 + 2*numlen)) {
*outlen = 1 + 2*numlen;
return CRYPT_BUFFER_OVERFLOW;
}
LTC_ARGCHK(out != NULL);
/* store byte 0x04 */
out[0] = 0x04;
/* pad and store x */
zeromem(buf, sizeof(buf));
mp_to_unsigned_bin(key->pubkey.x, buf + (numlen - mp_unsigned_bin_size(key->pubkey.x)));
mp_to_unsigned_bin(key->pubkey.x, buf + (numlen - xlen));
XMEMCPY(out+1, buf, numlen);
/* pad and store y */
zeromem(buf, sizeof(buf));
mp_to_unsigned_bin(key->pubkey.y, buf + (numlen - mp_unsigned_bin_size(key->pubkey.y)));
mp_to_unsigned_bin(key->pubkey.y, buf + (numlen - ylen));
XMEMCPY(out+1+numlen, buf, numlen);
*outlen = 1 + 2*numlen;